ABSTRACT. RePublic_ZEB is a running IEE funded research project, which aims to develop economically sustainable strategies and policies to enforce the refurbishment of the public building stock towards nZEB levels, according to EU 20/20/20 target. In the research project the nZEB regulations of the participant countries were compared, a common definition of nZEB was proposed. In order to develop strategies and guidelines about refurbishment of the public building stock towards nZEBs reference buildings were defined and costs/benefits analyses of the packages of measures for the refurbishments were performed. The paper presents three different calculation methods in a Hungarian reference building. To determine the cost optimal and nearly zero energy levels building energetic calculations were performed with three different methods: - The Hungarian national regulation defines a methodology for building energetic calculations, which should be used for every refurbishment in the country. The methodology is based on the yearly energy demand and energy consumption, and contains simplifications to be able to calculate the energetic indicators of a building in a fast and efficient way. - The participant members of the research project developed a calculation tool. This excel tool is based on EN 15603:2008, and it is able to calculate the monthly energy demand and energy consumption of the reference buildings. Large number of energy efficiency measures will be analysed to find the cost optimal and nZEB ranges. As all the participant members will calculate all their reference buildings with this tool, the results will be comparable. - To examine a more detailed calculation of the packages of measures, dynamic simulations were run with TRNSYS. This paper presents the results of the three different methods.

ABSTRACT. Many buildings erected more than about thirty years ago lack of an effective facade insulation. Some of them can be seen in old residential neighbourhoods, with parts of their concrete structures exposed to outdoor air and sunlight, single pane windows, thermal bridges, etc. Renovation of these facades leads to energy savings and more comfortable and healthy indoor air conditions.An opaque ventilated facade (OVF) is an easy and economic system to reduce heating energy consumption. In this paper the thermal loads of a building with and without an opaque ventilated facade system were simulated for an european country in the winter season to obtain the heating energy savings. A sensitivity analysis was also performed to identify the most influential weather variables on the energy savings. The results showed that solar radiation on the facade is the most influential variable, but certain combinations of low wind speed and high temperature levels can also lead to considerable energy savings, even with low solar radiation. With this information it is possible for designers to decide if a location is suited to install an OVF system.

ABSTRACT. Object of the H2020 project ‘MORE-CONNECT’ is to develop and to demonstrate technologies and components for prefabricated modular renovation elements in five geo-clusters in Europe (The Netherlands, Denmark, Estonia/Latvia, Czech Republic, Portugal). This includes prefabricated durable, innovative, modular composed building envelope elements for the renovation market, including the prefab integration of multifunctional components for climate control, energy saving, building physics and aesthetics, with advanced easy to use plug&play connections (mechanical, hydraulic, air, electric, prefab airtight joints). MORE-CONNECT offers tailor-made renovation concepts, from a standardized industrialized manufacturing and assembly process, in a one-shop-stop concept to the end-user, with a nearly zero energy performance of the total modular renovation concepts, a maximum return on investment less than 8 years and with a limitation of the total renovation time of 5 days. The concept offers performance guarantee for individual energy use and the quality of the indoor environment. Product innovation includes the selection of sustainable materials and sustainable detailing. A specific feature is the development of Plug & Play connection of modular components. Smart combinations of components and executions ensure extra performances for NZE concepts, healthy indoor environment, safety, accessibility. Components communicate by integrated (wireless) sensors and control components for performance diagnostics and control. Process innovation will be achieved by the use of advanced geomatics to make inventories of buildings. Webbased tools will link building characteristics, building (energy) potentials, and end-users demands to program requirements. This will be processed in BIM systems for the steering industrial process and enhanced quality control. This makes it possible to make tailor-made solutions for individuals, in mass production (n =1 series). Business models and advanced energy services (one-stop-shop) will be developed for each geo cluster.

ABSTRACT. Although the energy consumption in Europe is expected to rise only moderately in the next 20 years, the Energy Efficiency Buildings European Initiative has the objective to mitigate this problem aiming a reduction of 165 million tons of emissions (Mtoe) from the existing buildings (in 2005) and a contribution of 50 Mtoe from renewable energies during the period from now until 2020. Existing public buildings have a huge impact on the total energy use in Europe. The potential for energy savings is thus particularly important at national and European level, where many facilities are very energy-intensive, and where the priorities are the functional quality of the buildings and the respect of optimal use conditions.

Within this framework an FP7 EU project “Retrofitting solutions and services for the enhancement of Energy Efficiency in Public Edification (RESSEEPE)” technically advance, adapt, demonstrate and assess a number of innovative retrofit technologies, where reductions in the area of 50% will be achieved in terms of energy consumption.

The present paper is based on showing the work carried out by the authors in this project developing and adapting different numerical simulation tools for the thermal and fluid dynamic behavior analysis of different technologies for retrofitting solutions. Four of the different technologies that are being implemented in four European public buildings have been numerically analyzed in order to have a better understanding of their behavior and virtually analyze their energy efficiency for optimization purposes.

Aerogel-based super insulating mortars have been analyzed looking for optimum size of aerogel within the super insulating mortar looking for the lower thermal conductivity, Influence of envelope and thermal bridges on vacuum insulating panels have been studied to analyze their influence on effective thermal conductivity. PV panels coupled with ventilated façades have been studied in order to obtain the optimum gap of the ventilated façade depending on climate conditions. Finally, new flat plate solar collectors have been optimized by means of these tools obtaining a high efficiency thermal collector for a wide range of working conditions.

These different technical solutions have not only numerically analyzed for optimization purposes but also studied for different working conditions under specific climate conditions to be implemented in four different real public buildings as retrofitting solutions. The numerical methodologies, the numerical results obtained, different experimental comparisons and energy reduction expected are going to be analyzed, presented and concluded.

ABSTRACT. The objective of the project (INSULAtE) was to assess impact of energy retrofit on indoor environmental quality (IEQ) and occupant satisfaction and wellbeing, and to develop a common assessment protocol. The assessment protocol includes measurement of building related parameters (ventilation rate, pressure difference across envelope, thermal conditions), IEQ parameters (including carbon dioxide (CO2) and carbon monoxide (CO) concentrations, and various indoor air pollutants), and questionnaires to the occupants. Assessments have been performed in 45 Finnish apartment buildings before and after energy retrofits. This paper focuses on assessment of CO2 concentrations and ventilation rates. The majority of the buildings were built between 1960 and 1980. Most typical retrofitting actions performed included installing new windows, adding heat recovery system for ventilation system, and / or adding thermal insulation on external walls. Majority of the buildings had mechanical exhaust ventilation system, where more efficient exhaust is typically turned on for two hours once or twice a day: in the morning between 6am and noon, and in the afternoon between 4pm and 8pm. Air flows were measured from the exhaust vents using rotating vane anemometer (Testo 417) with built-in 100mm vane and temperature probe, based on which the ventilation rates were calculated. Carbon dioxide (CO2) and carbon monoxide (CO) concentrations were measured every minute during a 24-hour period, usually in the living room, using portable meter (Delta OHM HD21AB/HD21AB17). The 24-hour average CO2 concentration was 731 ppm before energy retrofits and 722 ppm after retrofits. The average CO2 concentration between 5pm and 8am was 680 ppm and 652 ppm before and after retrofits, correspondingly. Therefore, CO2 concentrations both before and after retrofits were relatively low. The average ventilation rates were 0,44 ACH before and 0,48 ACH after retrofits. The ventilation rates varied between 0,02 … 1,04 ACH before retrofits and between 0,03 … 1,57 ACH after retrofits. The lowest values were measured when exhaust was off. Some correlations between ventilation rate and CO2 concentrations can be found from measured data. The CO2 concentrations and ventilation rates were improved after retrofits in most cases. However, in some cases opposite trends were seen. Pressure differences across envelope and inlet routes of supply air are expected to change as a result of a retrofit, especially if the airtightness of building envelope is improved. Therefore, it is important that the ventilation system is re-balanced after such retrofits. Measurements of CO2-levels and ventilation rates before and after energy retrofits can be used to assess the situation.

ABSTRACT. INTRODUCTION The building sector is responsible for approximately 40 % of the Danish energy consumption. As only 1 % of the building stock is demolished and rebuild every year, energy efficiency enhancement of existing buildings are in focus. In the late seventies to mid-eighties energy efficiency retrofitting of residential buildings resulted in several cases of indoor climate degradations including extensive mould growth resulting in unhealthy indoor environments. This project describes possibilities, barriers and methods of combining energy performance and indoor climate enhancements when retrofitting rental dwellings. METHODS The project followed three energy retrofitting projects of rental dwellings through both planning and construction. Energy performance and indoor climate quality were assessed before and after the retrofitting. The assessments were made using simple classification tools for both indoor climate and energy performance. The energy performance was measured through the Danish mandatory model for assessment of building energy performance and compared to the actual energy consumption data. The indoor climate was assets by the Danish Standard DS 3033 “Voluntary classification of the quality of the indoor climate in residential houses, schools, childrens’ day-care centres and offices”, assessing ventilation rate, thermal indoor climate, radon, formaldehyde, particle, moisture and access to daylight. RESULTS and DISCUSSION The results showed significant difference between expected and measured energy consumption in one building and good agreement in the two others. The results indicate strong impact of good maintenance and operations on a building energy performance. The classifications according to DS 3033 show minor improvements in indoor climate quality after retrofitting. The simple assessments did not include improved thermal climate as a result of increased temperatures of inner surfaces after retrofitting. Access to daylight was not improves as much as expected due to reluctance to have bigger windows among existing tenants. Furthermore interviews to reveal the motivation of the landlords for retrofitting the dwellings, and the tenants experience were carried out and the project planning process has been observed. This showed a wide differing motivation among the landlords, a predominant positive response by the tenants and proof of utilisation of advanced tools for design of retrofitting measures beyond the legal obligations under the planning processes. CONCLUSIONS Neither the mandatory energy performance modelling nor DS 3033 are perfect “easy to use” classification tools for a retrofitting project. However, it is adequate to use the parameters of DS 3033 to make assessment targets for indoor climate quality. By assessing energy performance and thermal indoor climate by advanced tools beyond the simple legal energy performance modelling the rental dwelling marked is a far step ahead of most retrofitting of owner-occupied dwellings and houses.

ABSTRACT. Buildings and the whole built environment are in a key role when societies are mitigating climate change and adapting to its consequences. More than 50% of the existing residential buildings in EU-25 were built before 1970. Thus, these buildings are of significant importance in reducing energy consumption and CO2 emissions. The existence of more nearly zero energy buildings (nZEB) is a possible solution for this problem. This study aims to analyze the application of the nZEB methodology in the retrofitting of a typical Portuguese dwelling build in 1960. It was shown that the primary energy used can be reduced to a very low value (11,95 kWhep/m2.y) in comparison with the reference consumption (69,15 kWhep/m2.y), with the application of the best construction techniques together with the use of energy from on-site renewable sources.

ABSTRACT. Introduction: RenovActive House is a single family house of the social housing company Foyer Anderlechtois, located in Brussels, in the garden city Bon Air in Anderlecht. The renovation is based on the concept of “Climate Renovation”: to renovate houses to create an excellent indoor climate with a good energy performance. Several renovation scenarios were considered, their performance was analysed according to the Active House specifications. The concept is developed to be reused by the FA to renovate 86 other houses in the same area.

The house from the mid-1920s is compact, semi-detached and in a very bad condition. An architecture competition was organised to generate new ideas and innovative concepts for the climate renovation. The window design has been optimised for daylight and natural ventilation. The staircase window e.g. functions as an extract for natural ventilation that helps prevent overheating. To ensure good indoor air quality, a hybrid ventilation system is used, mechanical extraction ventilation when the outdoor temperature is below 14°C. Natural inlet through window vents integrated in the windows. Next to this, natural window ventilation is active all year; as peak ventilation during cold periods and as the main ventilation as soon as the outside temperature exceeds 14°C. Sensors are used to determine when there is need to open windows. The air in- and out-flow happens through automatic opening of the windows, profiting from the stack effect.

After completion of the renovation works (foreseen in spring 2016), the house will be open for visits during 1 year. After this, it will be handed to the Foyer Anderlechtois and inhabited by a social housing beneficiary. During the first 2 years of occupation, the performance of the house will be monitored; technically by measuring indoor climate parameters and energy performance, and also by psycho-social techniques like questionnaires.

ABSTRACT. This paper addresses the implementation of ventilation systems within the context of energy retrofit of residential buildings. The cost of energy retrofit is the main barrier to an increase of the retrofit rate in Europe. Among the retrofit measures, ventilation is often neglected to allow a more significant part of the budget to façade insulation, window exchange or for the heating system. The importance of a good ventilation system in order to guarantee a correct indoor air quality as well as to avoid high heat losses has been underlined by a large number of scientific articles. Therefore, an analysis of the costs of different ventilation systems within the context of energy retrofit is necessary. As a first step, our investigations are based on case studies and performed according to the VDI guideline 2067, analysing the costs with the annuity method and classifying them into 4 categories: - annuity of capital related costs (investment costs), - annuity of maintenance costs, - annuity of electricity costs, - annuity of heat energy costs.

This analysis leads to a comparison between 5 ventilation concepts: - no ventilation system (window ventilation) - central exhaust ventilation - central heat recovery ventilation - dwelling central heat recovery ventilation - decentralised heat recovery ventilation (single room units)

A more specific analysis of the investment costs of central heat recovery ventilation systems, based on three detailed case studies, is proposed and the potential for costs reductions is underlined.

As the costs are provided by different sources and for different buildings, the reliability of this comparison is questionable. Therefore, virtual costs have been calculated for a unique building for different ventilation systems. The strong influence of the airflow control strategy on the energy costs makes it necessary to distinguish the different systems also according to this criterion.

At first, the high spread between case studies shows that the implementation of ventilation systems within the context of building retrofit is not mature yet and still requires more experience to harmonise practises. Secondly, it is confirmed that heat recovery ventilation is globally more expensive than exhaust ventilation with average annuities of around 8.3 €/m².a against 4.9 €/m².a. Other criteria like environmental impact, hygrothermal comfort or indoor air quality are necessary to justify these extra costs. A third conclusion is that among the heat recovery systems, central systems are the most expensive ones with average annuities of around 9.2 €/m².a against 8.1 €/m².a for decentralised systems. At last, it is shown that demand controlled ventilation with moisture control leads to a significant cost reduction of exhaust ventilation systems (-34 % in comparison with constant airflows) as well as of heat recovery systems (-21 % in comparison with constant airflows).

ABSTRACT. The BELOK Total Concept is a method that motivates property owners to carry out larger energy renovation projects with maximum energy savings in a cost-efficient way. The purpose of the present work is to clarify the benefits and business opportunities in using the Total Concept method. In order for the method to be used on a larger scale, there must be commercial interest from the different companies to provide services with the method. The target groups are among others engineering companies with energy consultants, design engineers and architects, contractors and technology providers, energy controllers and ESCO companies. The article provides a market analysis of possibilities and barriers for energy renovations that have been carried out in Finland, Denmark and Sweden together with experiences from pilot buildings where the Total Concept method has been applied. The estimated annual market volume of renovation in the three Nordic countries is estimated to be about 4 million m2 and the total investment volume up to 280 MEUR per year. For the key actors involved in the Total Concept method the annual market volume is estimated to be about 70 MEUR. Furthermore, a new relevant key function relevant for the process, called a Total Concept Manager, has been identified.

ABSTRACT. INTRODUCTION: The Directive on the Energy Performance of Buildings requires that in the following years the EU Member States set cost-optimal levels of energy performance criteria in their regulations, while the methodology of determination of the cost-optimal levels is still in development. The reduction of energy consumption is to a large extent associated with the renovation of the old housing stock. This paper presents a case study of a selected representative apartment buildings A, B in Slovakia, for which the cost-optimal levels of energy performance are determined in terms of life-cycle costs of the building. Buildings are made of different materials – A: brick walls, B: panel walls; different year of construction; different floor area, height and volume.

METHODS: Calculation methods are the same for both apartment buildings A,B. At first, an energy performance calculation is performed for the building in its original condition, followed by calculations for several variants of renovation of the building envelope, heating system and domestic hot water, each variant representing a different level of energy performance. The calculation of life-cycle costs of the building is focused on a period of 30 years and includes the costs of investments, operation costs of heating and domestic hot water (DHW) and the costs of repairs of the apartment building. Besides of the total life-cycle cost, Net Present Value (NPV) and Net Present Value Quotient (NPVQ) are used as the criteria of profitability of the energy saving measures.

RESULTS: From the life-cycle costs point of view the variant with the highest level of thermal insulation can be considered as the most profitable, both for building A and also for building B; although the initial costs are highest, the low operation costs ultimately lead to the lowest costs during the whole life cycle of the building. However, the cost of debt service was not considered in the calculation. From the NPVQ point of view the following measures can be considered as the most profitable: insulation of distribution pipes in the DHW system, automatic control system and night temperature setback in the heating system, insulation of the distribution pipes in the heating system. The saving measures associated with thermal insulation of building constructions are more costly and less profitable.

CONCLUSIONS: The analysis showed a potential of energy consumption reduction of more than 50 % by implementing the energy saving measures. The thermal insulation thickness of 0.20 m can be recommended as optimal for the external walls for both A-brick, B-panel buildings, for the roof it is 0.30 m. Apartment building B has also thermal insulation of floor 0.04 m thick to fulfil the requirements on thermal protection as defined in the Slovak national standard.

ABSTRACT. In 2009, the Community of Moulins decided to renovate its library (area = 3315m2) which was built in the 1980s. The renovation of the building had two main objectives: Energy-efficient Renovation (Label refurbishment with Low consumption Building) and use of local resources such as the use of local ground water. The cost of the renovation was 1397 €/m². The cost of heating, ventilation, cooling and the room for local computers servers was 200 €/m².

ABSTRACT. The regional government of the Basque Country has established a double objective for social housing buildings: to supply free heating in the new constructions and to achieve a cost-optimal refurbishment solution for the existing buildings. It is analyzed the improvement of the energy performance of social housing buildings during the last decade. The analysis includes new buildings and renovations of existing residential buildings. The initial stage of new buildings implemented some renewable energy systems, such as Combined Heat and Power units, solar thermal panels. The second stage reduced the heating demand by demand controlled ventilation and combined conventional systems with Ground Source Heat Pumps or Trombe walls. The present stage has achieved a Zero Energy Building and expects to improve the minimum comfort levels for tenants. It is explained how has been achieved the optimal system operation and the contribution of each system to the final zero energy balance. The renovation of existing residential buildings is analyzed by the results of the main grant programs that have been applied in the last 3 years to more than 1000 dwellings. These grants demanded a reduction of at least 50% of heating consumption and a verification through 3 years monitoring. To conclude, several improvement possibilities will be demonstrated and some additional ideas will be suggested for future social housing projects.

ABSTRACT. The latest directives of EU commission enforce the shift toward renewable energy resources, stating that all new buildings should reach the Nearly Zero Energy standard by 2020, and are re-opening the question of the efficiency and the future of existing building stocks. Current researches in the field of urban design are exploring different strategies how to improve the energy-efficiency of our cities. Regardless of the chosen aspect of analysis;(1) thermal refurbishment and development of innovative retrofit façade solutions;(2) establishing the optimal urban density and searching for balance between transport and building energy consumption;(3) improvement of solar exposure in existing building environment; the final goal is to make cities green and self-sustainable. In this process of city metamorphosis a significant contribution would be to find a solution for the modernist large housing estates. The hyper production of the estates between 1950’s and 1980’s across Europe and worldwide left many cities with significant energy consumption. Only in Germany, about 1,7 million living units were built. In Poland and Hungary around 14 million is living in such housing. In the aforementioned context, this paper will focus on the optimization of large modernist housing estates which, thanks to both “Corbusian” urban design principles and urgent reconstruction demand, could allow experiments both in the field of urban density and optimal solar exposure. The optimization process should lead towards spatial configuration that ensures maximal density in correlation with sufficient solar exposure and minimal shading between buildings. Within the frame of two extreme approaches towards existing structures, such as total demolition and total preservation, following simulation scenarios will be examined: 1. Total demolition – generating a new urban configuration in accordance with maximal solar exposure 2. Total demolition – generating a new urban configuration within the latest urban zoning regulations and in accordance with maximal solar exposure 3. Total preservation – generating supplements for existing urban layout; increase of the density under premise of maximal solar exposure 4. Partial preservation – approach which reinvestigates the existing context combining partial demolition and supplementary structures for existing urban layout; increase of the density under premise of maximal solar exposure. The simulation will be conducted using Grasshopper software including its weather simulation component Ladybug and optimization tool Octopus (evolutionary algorithm) and be evaluated by using a set of given parameters such as usable floor area and estimated solar radiation. The results will give an insight to which of the proposed solutions is satisfying the desired goal in the most efficient way and indicate if current planning regulations are allowing the possibility to build optimal solar neighbourhoods. The final objective of this paper is to confront the two dominating tendencies: demolition and reconstruction, under a premise of an energy efficient development schema, and set up a new decision-making pattern for future reconstruction policies of these housing estates.

ABSTRACT. We report on the study of six similar buildings built in an area of Gothenburg, Sweden, in 1971, which are now in urgent need of renovation. However, the owner of the buildings - a municipal housing company did not achieve a financially viable renovation of the pilot project. This meant that renovation on a similar basis for the remaining five buildings would not be possible. For this reason the housing company chose to undertake a vertical extension, by adding two floors with apartments on top of the existing buildings. This has improved the economics and made renovation of the five buildings possible. The objectives of this study are therefore, to show how a vertical extension can make a renovation of these buildings financially viable. We argue that a vertical extension can be applied to other similar buildings from this era. If vertical extensions could make more renovations possible this would lead to a significant impact on final energy use and carbon emissions. This case study has been supported by a site visit, interviews with the housing company and the contractor, document analysis, energy simulation and global warming potential simulation. Four renovation concepts are compared in order to find the most appropriate: minimalist, code-compliant, low-energy and low-energy plus vertical extension renovation. The conclusion of this study is that vertical extensions provide enough incentive to preform extensive energy renovations, which could reduce final energy use by more than 50%.

ABSTRACT. It is well known that reducing energy use by this amount, even to the level of “net zero” energy NZEB use, is technologically feasible in many locations and for many applications.Often refurbishments end up in low or even modest energy reductions which are a wasted opportunity for the remaining 30-40 years of the building´s life. Besides lacking legal incentives and enforcement strategies the foremost obstacles are lacking knowledge on bundling and inadequate business models: • DER refurbishments require an integrated approach to design that considers all energy sources and equipment in the building. DER is impossible to achieve with single-measure retrofits, which lead to suboptimal results. While much is known about the savings potential of single measures, there is not a great deal of experience in the selection and application of bundles of energy conservation measures (ECMs). • Lacking data: Few DER projects have been thoroughly evaluated, and knowledge is restricted mostly to modeling results. • Inadequate business models: The barriers to DER implementation are most often financial; in the public sector the availability of public money is limited. In other sectors money is available but does not move into energy efficiency and in DER projects due to unknown risks. Different strategies have been applied in the past to decrease cost of emerging technologies. • Business models that perform more efficiently should be preferred. EE is most commonly implemented in “owner directed” business models. Because they perform more efficiently, building owners turn to Energy Performance Contracts (EPCs).ion goals. In an EPC, an energy services company (ESCO) guarantees the performance. • EPC increases the available funding because the project is financed by the recurring energy and energy-related cost savings generated by the measures themselves, thereby avoiding the need for capital appropriations by the government. This approach follows the fact that guaranteed performance parameters can be integrated in financing schemes without increasing the debt of building owner. The paper will present findings of the assessment and advancement of business and financial models for DER projects which was carried out under IEA Annex 61 and which will be published in a business model report by April 2016. The paper will focus on the major topics of the research work at the hand of a case study carried end of 2015 in a dormitory in Germany: • Assess synergies between various technologies that reduce energy and maintenance costs; • Development and implementation of an advanced EPC business model with an extended scope of measures towards DER with integrated energy- and non-energy related life cycle cost benefits of DER into financing mechanisms; • Defining the interface between investors, ESCOs, and building owners by developing eligible quality assurance mechanisms that minimize the risks related to the achievement of energy and life cycle cost goals and by this contribute to reduce risk related capital costs;

ABSTRACT. Introduction Following the fire in the former faculty building in 2008, the Faculty of Architecture of the TUDelft moved into the former main TU Delft building. The building was initially regarded as a temporary home, but it has now been decided that Architecture will remain in the building, now renamed BK City, for the longer term (30-50 years). BK City must therefore be made more efficient and sustainable to meet future needs [1].

Therefore, the building needed improvement, especially for what concerns the indoor climate (upgrade) and sustainable repair of the structures. This is the focus of the second phase of the intervention, ‘BK-City Stay!’, improving the comfort in a durable and sustainable way [2].

Methods The renovation of their own Faculty was an excellent opportunity for the students of the Master Track Building Technology to study the renovated building and check if the indoor climate has indeed improved after the renovation. Within the course “Technoledge Climate Design” 16 master students, in groups of 2, performed surveys, conducted measurements and executed computer simulations to investigate the indoor climate after the renovation. The four different indoor comfort aspects, thermal-, visual-, acoustical comfort and indoor air quality, were taken into account. The aim of the course is that the students learn how indoor environmental parameters affect health and comfort.

Results User assessment after the renovation showed that the users are still not very satisfied with the indoor climate. Measurement of indoor temperatures and the indoor air quality supported these conclusions.

Discussion After the physical renovation is finished, it still takes a long time before the indoor climate in the building is well regulated. It might be caused by the way in which the renovation of a complex building and its installations is managed. It may also be caused by the robustness of the improved climate design as suggested by Kurvers et al. [3]. Or it might just be a problem of modern complex energy renovations where monitoring after the physical renovation must be included in the renovation process.

Conclusion For the Architecture building it must be concluded that after interventions in such a complex building additional monitoring and adaptations are necessary. In this case, students performed the measurements which had the advantage that the students gained practical knowledge and the building management received valuable data on the performance of its building.

1. https://intranet.tudelft.nl/en/a/bk-city-building/bk-city-stay 2. R. van Hees, S. Naldini, J. Roos , Durable Past- Sustainable Future, TUDelft, 2014

ABSTRACT. During 2007-2012 period a very important historical valuable building in the centre of Vicenza was retrofitted by both structural and energy/mechanical plants points of view. Particular attention was paid to the heating, ventilation and air conditioning plant; it was retrofitted installing an underground water source electrical compression heat pump. During the design phase a monitoring and data logging system was provided in order to log many data concerning energy flows and the main operating parameters. In this paper the analysis of the performance data of the 2014 and 2015 cooling seasons and the 2014/2015 heating seasons is developed. Such monitoring activity is also requested by the local Authority in order to verify both the utilization of underground water and the energy performances of the HVAC plant. The analysis reveals that, even if appreciable energy savings with respect to more traditional plants were expected, some critical aspects determined poor energy performances of the plant in the first operation period. This work presents such issues and the technical solutions suggested by the Authors, recently implemented to improve the energy performances of the plant. Data of the first period after the technical optimization are also reported and analysed.

ABSTRACT. In this study, experimental performance analysis of a solar assisted heat pump space heating system (SAHPSHS) installed in Antalya was performed for low (mean value of 55 W/m2), moderate (mean value of 465 W/m2) and high (mean value of 810 W/m2) solar radiation. Antalya has a moderate climate and high solar radiation in winter thus, the highest heating requirement occurs after the sunset. Therefore, unlike common solar-assisted heat pump systems, a storage tank with 2-ton capacity was used for heat storage. The system was designed to operate also on the days when the solar radiation was insufficient thus, the tank temperature was lower than the limit value. In such days, storage tank was supplied by the city water as an auxiliary thermal source. For the performance evaluation, energy and exergy analysis is conducted. Thus, the coefficient of performance (COP) of heat pump and overall system and the exergy destruction rate of each component are determined. It is found out that the highest exergy destruction was occurred in the evaporator.

ABSTRACT. Ground Source Heat Pumps are energy-efficient HVAC systems usually adopted in residential and commercial buildings. However the control of the thermal environment is required not only in spaces occupied by people, but also in intensive breeding farms, in order to maintain healthy conditions and to increase productivity. In the Italian livestock breedings, heating is usually provided by means of gas or Diesel burners directly installed in the stables, an important part of the heating load being related to the large ventilation rates required for the livestock well being. Cooling is either not provided or achieved by evaporative systems that also increase the humidity level in the stables, thus requiring even larger ventilation rates.

Therefore the applicability of geothermal heating and cooling in breeding farms was analysed in a research project co-funded by the Lombardy Region and the Italian Ministry of Research and Education. A pilot system for heating, cooling and ventilation was designed and installed in a piglet room at the Experimental and Didactic Zoo-technical Center of the University of Milan. Five Borehole Heat Exchangers (BHEs), installed down to a depth of 60 meters into an alluvial aquifer, were coupled with a Ground Source Heat Pump. The heat pump provides heating and cooling to an Air Handling Unit, including a Heat Recovery system. A monitoring system was installed in order to measure comfort conditions in the piglet room, operating conditions and energy consumption of the HVAC system, together with the spreading of the thermal plume in the ground.

In this paper the results of a monitoring campaign carried out in a typical winter period are presented and discussed. The overall energy efficiency of the system, expressed in terms of a COP, results to be equal to 4,04. A comparison between the pilot HVAC system and a traditional one is also carried out, showing that the proposed solution can provide over 40% primary energy saving. Following, cost savings in energy bills for farmers are found, although the ratio between electricity cost and fuel cost is a key parameter.

ABSTRACT. In the energy efficient buildings the percentage share of energy for heating and cooling fresh ventilation air in total energy demand of the building constantly increases. In the air-tight and well insulated buildings mechanical ventilation systems with heat recovery and earth-to-air heat exchangers (EAHEs) are used to diminish the energy demand for heating and cooling of fresh ventilation air. Multi-pipe EAHEs are used for buildings such as offices, markets, gyms and others, where large airflows are needed. The energy efficiency of such systems depends not only on the efficiency of heat recovery in the air handling unit, but also on the heat and cool gains of EAHE and the energy used by fans or blowers providing fresh air, which depends on the total pressure losses of EAHE. The total pressure losses of multi-pipe EAHE depends on many geometrical parameters of the exchanger. Especially important is the connection angle between main and parallel pipes. In this paper the influence of the connection angle between main and parallel pipes in multi-pipe EAHEs was investigated experimentally using several models of multi-pipe heat exchangers. The theory of similarity in fluid mechanics was used both for designing of the models and for experimental results interpretation. The total pressure losses and total airflow were measured for various air flow rates values. An original non-invasive method of airflow measurement based on linear pressure losses of smooth pipes at the measuring sector for fully developed flow were used. The angles 45, 90 and 2x45 degrees were taken into account. The flow characteristics in the form of the total pressure loss coefficient vs. Reynolds number are presented and compared for different angles. The results show that the angle of connection between main and parallel pipes of multi-pipe earth-to-air heat exchangers significantly affects the total pressure losses and consequently - the energy efficiency of mechanical ventilation system. It was shown that the angle of connection 2x45 degrees in the most cases results in the lowest total pressure losses. It also seems to be the most convenient one from the installation point of view.

ABSTRACT. Using municipal or residential waste water (WW) as an energy source for heat pump systems offers a great opportunity thanks to huge energy potential in WW, which is otherwise wasted. Recent interest in waste water source heat pump (WWSHP) technologies considers new component designs, mainly heat exchangers. In this paper, however, we focus on developing methods for optimal dynamic operation of a WWSHP system by employing advanced control and optimization algorithms. We consider an experimental WWSHP developed in Yasar University, Izmir, Turkey. We focus on the heating mode of the HP system, and compute optimal set points to compressor and condenser fan motor speeds to manipulate temperature of the cooling fluid as well as air temperature at the condenser exit. Preliminary results suggest that the MPC controller enhances the efficiency of the HP system in the presence of varying heat loads.

ABSTRACT. Heat pumps (HPs) have been used as an environmentally friendly technology for heating and cooling purposes since decades. They are not only named after the source (i.e. air source heat pumps), their efficiencies do also depend on the source that is being used. Wastewater (WW), discharged from buildings to sewerage systems, reserve huge amounts of thermal energy which can be used as heat source in HPs. It can also be considered as a sustainable and renewable source in big cities. WW from local residential drainage systems exhibits relatively high temperatures during the heating season, being about 14 oC in the Cigli district, Izmir, Turkey. WW, therefore, offers an ideal basis for utilization of heat. In summer, the WW temperatures are over 20°C, being between 28-29 oC in the same district. Therefore, it represents a much more efficient heat source than air, when used in HPs. The heat loss via WW for a traditional building in Switzerland accounts to 15% of its demand and 6000 GWh of thermal energy is lost via WW every year in Switzerland.

In the present study, a wastewater source heat pump system (WWSHP) installed at Yasar University, Izmir, Turkey was experimentally investigated. A local wastewater drainage system, through which WW flows, was not utilized because the designed and constructed WWSHP system could not be connected to it. Therefore, two 500 L tanks, where water was stored and circulated by pumps, were used to simulate it while all measured data have been continuously recorded since the operation of the system. In the first part of the study, the whole system along with each component was exergetically analyzed while exergetic destructions and efficiencies in each component were determined to present possible improvements. In the second part of the study, an appropriate building was selected for the WWSHP and was evaluated from the primary energy transformation to the building envelope using the low exergy approach and some exergy-based indicators.

ABSTRACT. Energy consumption for HVAC (heating, ventilation, and air conditioning) systems accounts for a large portion of the total energy consumption of a building. Improving the efficiency of an HVAC system will be helpful for energy saving. In an HVAC system, the energy wasted by running pumps is one of the important components of energy consumption. The pump power reduction under part-load conditions significantly contributes to the improvement in the efficiency of the HVAC system. On the other hand, the supply water temperature of a chilled water circuit is closely associated with the heat transfer characteristics of the heat-exchange equipment. An appropriate supply temperature will improve the heat transfer performance of the related equipment. In thermodynamics, energy can be divided into available and unavailable energy. Exergy is energy that is available for use. Most previous studies on above two factors were carried out mainly from the viewpoint of the amount of energy being used, and not the quality of that energy. But unlike conventional energy analysis, exergy analysis enables us to determine where and how much exergy is consumed Therefore, to elucidate the energy-saving effect of pumps along with the heat-transfer performance of terminal units in heat pump systems, a theoretical analysis of an assumed chilled-water circuit at two supply water temperatures (7°C and 12°C) under four variable-flow control modes (throttle valve control, constant pressure control, constant differential pressure control, and predictive system curve control) was carried out from the viewpoint of available energy, i.e., exergy. The demand side of the chilled water circuit is simplified into one terminal unit, fan coil unit, accompanied with one pump. Exergy input and exergy consumption of the system under different conditions are compared. Subsequently, based on the operating data, the exergy analysis of a part of heat pump system was carried out to verify the energy-saving effect after variable-frequency transformation of the chilled water pump. The exergy efficiency and the net exergy consumption per unit exergy output before and after the transformation are compared. The corresponding results based on the operating data of an actual heat pump system are consistent with those obtained through theoretical analysis. The results and conclusions obtained from the exergy analysis are as follows: (1) The exergy input and exergy consumption under each part-load condition is significantly less than that under the full-load condition. (2) Exergy input and exergy consumption of each variable frequency control is less that of the throttle valve control. In variable frequency controls, the exergy inputs reduce in the following order: constant pressure control, constant differential pressure control, and predictive system curve control. (3) Exergy input is less at a supply water temperature of 12°C than that at 7°C. (4) The use of variable-frequency control and a higher chilled water temperature can effectively reduce the exergy consumption and improve the exergy efficiency.

ABSTRACT. Earth tube is a underground pipe through which outside air is drawn to inside of buildings. Earth tube is considered as a passive heating and cooling technique that uses the relatively constant degree temperature of the earth to preheat in the winter season and precool in the summer season by passing the air through tubes buried under the earth before bringing it into the building. Therefore, earth tube system is considered as an alternative of low cost solutions to reduce the cost of heating and cooling energy in buildings. In this study, thermal performance of earth tube system with design variables variation of residential buildings in Korea will be examined and their impact on energy consumption will be presented with Energyplus simulation. Considered design variables are as follows. . Design Flow rate . Earth tube Pipe Length . Earth tube pipe depth under ground surface . Soil condition . Earth tube type : Intake, Exhaust . Earth tube Fan pressure rise . Earth tube Pipe Thickness . Earth tube Pipe Thermal Conductivity . Earth tube Pipe Radius

ABSTRACT. In the present paper the authors propose an improvement of a one-stage lithium-bromide absorption plant so that it can operate in two different modes –one as refrigeration plant with the heat generator powered by solar panels during summertime, and the other as heat pump during wintertime, with the potential of recovering the waste energy from the condenser and absorber. The experimental results were obtained using an experimental stand located in the Laboratory of the Department of Thermodynamics part of Technical University of Civil Engineering Bucharest. The hot water necessary to drive a single-effect (LiBr/H2O) absorption chiller of 17 kW nominal cooling capacity is provided by a 80 m2 array of flat-plate collectors. The aim of the study is to evaluate the performance under different operating conditions and the opportunity of using the heat recovered in order to heat the air in a heating coil.

ABSTRACT. The energy demand of buildings for heating and cooling is responsible for more than one third of the world’s final energy consumption. Therefore the identification of innovative heat supply concepts based on renewable energies is required. The utilisation of renewable energy sources (RES) in combination with high efficient supply technologies increases the “sustainability” of new housing areas. For a new housing area “Zum Feldlager”, located in Kassel (Germany), various supply concepts are investigated. Main objective is the development of an innovative and optimised heat supply concept based on renewable energies and a low temperature district heating. Central challenge in achieving this objectives is the identification of the most promising and efficient technical solutions for practical implementation. In order to identify the best possible system solution, different centralised and decentralised supply strategies have been investigated and compared. As decentralized supply options, two variants have been selected: an air-water heat pump and a gas-fired condensing boiler with solar domestic hot water supply. In comparison, two centralised variants have been considered. Both variants have a low-temperature district heating net for heat distribution, but have different heat generation technologies. The first one is based on a centralised ground source heat pump combined with decentralised solar thermal systems. The second centralized supply variant is a combination of a CHP units and a ground-coupled heat pump. The CHP plant can be driven by both fossil fuels (natural gas) and renewable energy sources (bio methane). The most innovative and best evaluated heat supply concept is based on the central ground source heat pump in combination with a low temperature district heating (40°C) for space heating and decentralised solar thermal systems for domestic hot water generation and solar thermal regeneration of the ground. The advantages of this supply variant are very low heat losses in the network and about 60% lower CO2-emissions and primary energy demand in comparison to the gas-fired condensing boiler. This project is a cooperative activity of the Fraunhofer Institute for Building Physics (IBP) in Kassel, IdE Institute for decentralised Energy Technologies, Kassel University, the City of Kassel and the local utility company Staedtische Werke AG. The paper will present a short description of the new housing area and the development and evaluation of the various supply concepts. In addition to that, the assessment and pre-selection of the heat supply concepts depending on quantitative and qualitative criteria will be described in detail.

ABSTRACT. Abstract A methodology is presented to identify HVAC control strategies for commercial office buildings that are appropriate for various Real Time Pricing (RTP) intervals. The electric utility is a summer peaking utility. The proposed approach is based on the premise that existing and new commercial office buildings deploy Building Automation Systems (BAS). Further, it is assumed that the building owner undertakes commissioning for new buildings and recommissioning for existing buildings. During the commissioning process, real-time data for various control strategies both for on-peak and off-peak periods are uploaded from the BAS to the customer’s Cloud. The building under consideration has both occupied and un-occupied periods. The data in the Cloud can then be analyzed to arrive at response times determined from the start time of the control strategy to the time the reduction in KW and Kwh values occur say at the end of say 5 minutes, 10 minutes, 15 minutes or 30 minutes to one hour. The corresponding outdoor air temperature is noted and placed in a 2 degree or 5 degree bin intervals. The need to match power generation to demand is critical to ensure reliability of the Power Grid. Demand Response in conjunction with RTP is a tool employed by many utilities to address this issue. Day-ahead notification of RTP at one hour intervals for commercial buildings and industrial facilities is often used. However, shorter intervals of the order of fifteen minutes or less is likely to become more prevalent to more closely match real time power generation to demand for non-residential buildings. The scope and methodology described in this paper vastly differs from the work of previous investigators. One author used an emulator for on-day strategy development to RTP and others used simulations to study the impact of VAV system control strategies. The electric utility load forecast is based on outdoor air temperature and the associated cost of generation determines the RTP for various intervals which in this paper is assumed to be available a Day Ahead to the customer. Hence, the reason for using the prevailing outdoor air temperature with the corresponding KW and Kwh reduction for each of the control strategies. This thinking is not applied to immediately responding strategies such as that occurs with lighting control. This RTP profile when coupled with day-ahead outdoor air weather data for the building location and the associated KW and kwh reduction for the applicable control strategies results in the development of setting up a time- of- day schedule for control strategies one day ahead for responding to the RTP the following day. The schedule is implemented by the building operator using the BAS. Additional research in integrating this approach with a Fault Detection, Diagnosis and System Restoration feature should strengthen the reliability requirements of the Smart Grid.

ABSTRACT. Worldwide awareness of the impact of global warming has led to new policies promoting the integration of renewable energy sources in the energy mix. Due to their intermittent character, their massive development threatens the stability of the electricity grid by introducing a mismatch between demand and supply. To guarantee grid stability, a shift from the "supply following demand" model to a "demand following supply" model by mean of flexible loads is needed. This presents a study of the potential of demand side management offered by a residential building stock with a percentage of houses equipped with heat pumps and thermal storage for both space heating and domestic hot water. The method is based on rule-based control of the systems in response to dynamic electricity pricing reflecting the introduction of renewable energy sources. It is illustrated by a case-study applied to the Belgian residential building stock for a scenario at the horizon 2030. The use of water tank for domestic hot water needs is of common practice in residential housing. For space heating needs, contrariwise, it hasn’t been widely investigated yet. When associated with heat pumps, such thermal storage can offer substantial flexibility to the electricity demand profile of the house and help shift the load from peak to off-peak hours. In this paper, a first analysis is carried out for a single house including optimal sizing of the storage tank as well as temperature control strategies. Two configurations are compared: the parallel hydraulic integration by four pipe connection and the parallel hydraulic integration by two pipe connection. The level of details to include in the models is also discussed. In the second part, the analysis is generalized to the scale of the building stock. As expected, increased peak demand and ramping issues are observed with increasing penetration rate of heat pumps. These issues can be partially tackled by introducing coordination between consumers to prevent all flexible consumers from simultaneously activating their heat pump. Results show that the Parallel hydraulic integration by four pipe connection leads to a substantial overconsumption which is not compensated financially by the use of dynamic tariffs. On the other hand, the Parallel hydraulic integration by two pipe connection provides a suitable solution. Cost savings for the consumer reach up to 4.4%. The coordination mechanism between consumers allowed to reduce the peak demand increase by 19% to 31% without significantly impacting the cost savings.

ABSTRACT. INTRODUCTION Recently, an energy management system (EMS) and storage equipment such as batteries and thermal energy storage (TES) have become increasingly important for optimizing operating schedules to reduce operating costs. Although, there have been many previous studies which aim to optimize the operating schedule of energy system, they have considered perfect predictions of demand and PV power generation. However, the prediction is often different from actual phenomena. In addition, some studies considering the uncertainty only provided a method to measure the effect of each factor such as outdoor temperature and irradiation to the objective function. Thus, an effective method proposing how to control each component under the uncertainty is strongly needed.

METHODS A simple and effective methods are to recalculate operating schedules of all time steps at every time intervals that called all time steps recalculation strategy (AtsR). AtsR can be thought an ideal optimal strategy, but it takes a lot of computation time. Thus, it is not easy to be applied to actual energy management system because we need to recalculate quickly operating schedules when the unpredicted demand change happens. Therefore, we propose a new recalculation strategy that is two time steps recalculation strategy (TtsR). It aims to recalculate operating schedules for two time steps when the change happens and next while fixing the amount of remaining battery and TES at next time step as constraints. We compared TtsR and AtsR in order to clarify the effectiveness of TtsR on four case studies: 1) prediction case, 2) considering the uncertainty of PV, 3) considering the uncertainty of demand change, and 4) considering both changes.

RESULTS and DISCUSSION In Case 2, the objective function that was total operating costs in 24 hours of AtsR and TtsR were 604633 yen/day and 608304 yen/day, respectively. The computation time of AtsR and TtsR were 4608s and 1290s, respectively. In Case 3, as a similar to Case 2, TtsR could reduce the computation time by 73%. The total amount of operating costs of AtsR and TtsR were 640985 yen/day and 641129 yen/day, respectively and increased by less than 0.02%. Thus, TtsR can cut computational costs by 73% while maintaining the computational accuracy.

CONCLUSIONS We compared TtsR with AtsR which optimizes the operating schedules of all time steps. Although AtsR could obtain the quasi-optimal solution accurately and AtsR was an ideal strategy in terms of minimizing the objective function, it needed more computation time. With comparison of two calculation strategies, TtsR could obtain a quasi-optimal solution in 73% shorter computation time than AtsR while maintaining the accuracy. Therefore, TtsR can be applied to any types of uncertainty and energy systems regardless of installed energy equipment and contribute to manage an energy system in actual buildings.

ABSTRACT. Recently there has been increased interest in the potential of Demand Response (DR) as a possible measure to facilitate increased penetration of renewable energy sources in the energy supply mix. To achieve this goal, the potential of the building sector as a demand response resource is of interest to power systems industry. A key challenge to utilize this resource is to meet the utility/aggregator requirements. These requirements determine the magnitude of the load that should be shifted or curtailed, the time at which the response should be activated and the response duration. A control strategy that responds to the different requirements and adjusts building energy demand profile is necessary to identify the appropriate shiftable building loads and control them without noticeable impact on occupant comfort. Of considerable interest is the implementation of DR measures in the commercial building sector. Commercial buildings typically include a wide variety of electrical loads, which when coupled with significant building thermal inertia, can be used to shift or reduce the on-peak consumption, while maintaining thermal comfort within acceptable limits. Heating, cooling and ventilation loads, which are associated with the building thermal inertia, constitute the main opportunities to be exploited for DR purposes The objective of the current paper is to investigate the effectiveness of DR strategies targetting building thermal loads, with the aim of modifying the electricity demand subject to different requirements, while satisying occupant thermal comfort. A building simulation model using EnergyPlus, is used to create a DR testbed, utilising a mixed use commercial building as a case study. The building, located in Ireland, is used as a sports/entertainment centre with a floor area of 11,000m2, which contains a gym, a 50m x 25m swimming pool and additional facilities including: offices, meeting rooms, performing arts theatres and retail units. An energy demand analysis facilitates the breakdown of the building electricity/energy consumption as well as the seasonality of different HVAC system loads. This analysis is utilized to create targeted DR strategies, which are examined using the simulation model to assess their effectiveness, subject to different building schedules, as well as different external and internal boundary conditions. Space and water heating, lighting and ventilation are identified as the three major end-use categories accounting for more than 60% of the final energy use. Different DR requests are evaluated based on the start time and duration of DR events and evaluated based on the variations in building load demand as well as zone variables, such as air temperature, relative humidity and CO2 concentration levels, related to occupant comfort. Pre-conditioning some of the zones coupled with air temperature set-points modification, was found to provide up to 7% reduction in the building electric power demand without exceeding occupant comfort limits on summer weekdays. The results indicate that DR strategies utilizing building passive thermal mass offer a considerable load shifting/curtailment potential which could be utilized in a DR event while ensuring occupant comfort.

ABSTRACT. This study aims to develop simplified multi‐zone building thermal models through model reduction strategies and to explore opportunities for reducing peak power demand due to space conditioning. By creating suitable simplified multi‐zone thermal models of buildings, model based control strategies – for purposes of energy reduction, peak power reduction or occupant thermal comfort – can be quickly evaluated and identified. Through model reduction, adequate accuracy should not be lost within the model and model predictions should be meaningful for the whole building and zone level energy and power results. Models are being studied and developed for future use in control oriented modelling or MPC and studies for easily implementable peak power reduction and energy reduction strategies. The paper compares real data from an unoccupied detached test home facility to three multi‐zone models of varying detail. The test facility is built as a typical detached residential home with a garage, basement, main floor and second storey, built to 2011 building codes of Quebec, Canada. Also, control strategies for space heating are investigated with the aim to reduce consumption and peak power due to space conditioning on very cold winter days. The homes are heated with individual room baseboard heaters with no active air mixing (ie. no air distribution system). A four zone model of the 3‐storey house is used for the purpose of simplified model identification and peak power calculations used for peak power reduction studies. The most detailed model has 4 zones, each with separated walls, windows, doors etc., resulting in a model with 32 capacitances. Each zone represents a level/storey of the house. The thermal mass of the envelope structure is considered as one capacitance in this scenario. Two simplified models are then created and compared with the detailed model. “Simple Model #1” takes the features of the detailed model but combines surfaces to effective areas, creating 14 capacitances and resulting in fewer equations to solve at each time step as well as a simpler calibration procedure. The thermal mass layer of the envelope is discretized into one single capacitance in the middle of the layer. The “Simple Model #2” is similar to the first simple model but considers 12 capacitances by omitting the thermal mass layer in the floors/ceilings between the zones and lumping the inter‐zonal conduction and convective transfers to one effective resistance value. An optimization algorithm was employed to identify certain parameters, thus creating grey‐box models. Next, using the grey-box models, by varying start times of zone set point profiles or introducing preheating, overall household peak can be reduced by roughly 30% on the coldest day of the year. The “Simple Model #1” of a 4‐zone building was found to be superior at the zone level to the “Simple Model #2” and has a CVRSME value of 14.5% for the whole building, while the most detailed model has a CVRMSE of 12.2%. It can be concluded that a four zone simplified grey‐box model of a 3 storey house is adequate for the purpose of control‐oriented modelling and can be used in future control studies.

ABSTRACT. INTRODUCTION A new settlement is planned nearby Bergen, Norway, with the goal to reach a Zero Emission Building (ZEB) target for the entire neighbourhood considering the total energy demand of the buildings: heating, hot water, ventilation, auxiliaries, lighting and plug loads. The Zero Village Bergen consists of more than 700 dwellings divided between terraced houses (68% of total floor area) and apartment blocks (25%) and some area dedicated to non-residential purposes such as offices, shops, and a kindergarten (7%).

METHODS For residential buildings stochastic electric load hourly profiles are obtained from a Time of Use Data (TUD) methodology. The resulting aggregated electric load profiles for lighting and plug loads are normalized per household and used as input in the calculation of the thermal load. The thermal load is calculated by dynamic building energy performance simulations (in IDA ICE). The buildings are passive house buildings according to the Norwegian standard. For the non-residential buildings the energy demand has been calculated directly from real measurements of similar buildings and further adjustment to be normalized to a typical climatic year. PV generation profiles are obtained using state of the art software (PVsyst) considering the variety of roof orientations and shading effects from a 3D modelling. Both load and generation profiles are obtained as hourly averages and are based on the same weather data file in order to guarantee consistency when addressing the mismatch between the two.

RESULTS and DISCUSSION At aggregated level the Zero Village Bergen has a total electric need of 3.3 GWh/y with a peak load of 0.7 MW, and a thermal need of 3.2 GWh/y with a peak load of 1.3 MW. The PV system generates in total 2.9 GWh/y with a generation peak of 2.9 MW. Preliminary results only consider the buildings' energy needs, which coincide with the delivered energy for the electric specific part only. The full paper will also consider the case of an all-electric solution, with heat pumps installed in each building. The preliminary results show that at aggregated level the PV system covers 90% of the electric energy demand, and has a mismatch resulting in a self-generation of 32% and a self-consumption of 36%. Peak generation is 4.3 times bigger than peak load, and even considering the temporal match between the two – on an hourly basis – the net exported peak towards the grid (in summer) is 3 times as big as the net imported peak (in winter) from the grid.

CONCLUSIONS Although the PV system alone is not enough to achieve the ZEB ambition, the mismatch with the electric load causes large amounts of energy to be exported to the grid, with export peaks 3 times as big as the import peaks. Alternative energy system solutions will be investigated, such as a local heating grid with biomass based cogeneration, additional PV capacity on carports and the use of electric vehicles batteries (evt. additional stationery batteries), in order to achieve the full ZEB target and improve the interaction with the grid.

ABSTRACT. In a cold climate, electrical power demand for space conditioning during certain periods of the day becomes a critical issue for utility companies. Shifting a portion or all of it to off-peak periods can help reduce peak demand and to reduce stress on the electrical grid. Electrically heated floor systems consist of heating element embedded in a material with a high thermal storage capacity. Electrically heated floors can store thermal energy in buildings during the off-peak periods and release it during the peak periods while maintaining occupants’ thermal comfort. TRNSYS is a powerful and flexible simulation software. Nevertheless, no model has been developed for simulation of an electrically heated floor. This paper reports the development of an alternative method to integrate an electrically heated floor in TRNSYS and investigate the impact of floor assembly on the electrically heated floor performance. The results show that an electrically heated floor in a cold climate allows to completely shift the energy consumption.

ABSTRACT. The European Union, as well as in the public and private building sector, have goals, requirements and definitions that encourage energy efficiency improvement to enable reduced import of energy to the building as well as greenhouse gas (GHG) emissions. One of these definitions is nearly zero energy buildings (nZEB). Most of the nZEB definitions are based on annual values for delivered and exported energy. In order to reach nZEB in a robust and resource effective way, the energy grids may be used for both delivery and export. However, the reduction of primary energy (PE) demand and climate impact is not automatically achieved just by using the grid. The load matching between the building’s energy demand, the renewable energy production and the exported renewable energy is depending on when in time this occurs. An environmental assessment method for buildings’ energy use has been developed, taking into account the time resolution of energy use, import and export. For exchange of heating between the building and the district heating (DH) grid each DH system is analysed individually. A marginal mix of fuels influenced by a change in heat demand is calculated and resulting environmental impacts analysed. The assessment of electricity exchange between the building and the grid is done by a marginal approach identifying the technologies in the North European electricity system affected by a change in electricity use. By using the method as a sensitivity and risk analysis in the planning phase of new buildings, the stakeholders can avoid unpredicted consequences.

ABSTRACT. INTRODUCTION Solar assisted heat pump system is a technology many discussed in recent years. It represents an important integration in the air-conditioning of buildings due to the following advantages: high renewable energy share, low electricity demand, low primary energy demand, and low CO2 emission depending on the electricity mix feeding to the heat pump. The objective of this study is to investigate the benefits obtained from the adoption of innovative methods of managing heat pumps in order to increase the consumption of electricity produced from renewable sources. The logics of management induce to use the thermal units largely in times when sustainability of power generation is high by a photovoltaic plant on the building or by another renewable source connected to the electric smart grid. The logic of the management plan to maintain internal comfort in any condition and manage the thermal storage to accumulate the energy produced that is not immediately used. METHODS A detailed dynamic simulation code is used to model different types of buildings in different climate conditions and, cost/energy benefits are evaluated by the use of an integrated management of renewable and thermal generating units. A small residential building and a medium commercial one, both of them in two different climatic zones, are considered. RESULTS and DISCUSSION The results show important energy benefits with the use of the strategy of integration used in the simulations, the greatest benefits will are in the summer season when the PV production is high. In heating mode, the unit operates with higher efficiency because they work more in the daily period with a higher average outside temperature. CONCLUSIONS The study confirms the importance of using integrated management methodologies in order to increase the share of renewable sources used for the energy demand of the new buildings and also in energy-efficient retrofit of existing ones. It was possible to evaluate the influence of operating procedures in different case studies by determining the optimal configuration and its energy benefits. KEYWORDS Solar energy utilization, sustainable energy for buildings, energy efficient in heating and cooling systems

ABSTRACT. Zero Energy/Emission Building (ZEB) has become a term for buildings that are self-energy supplied or may even export energy. These buildings are characterized by energy efficient components and energy supply from renewable energy sources. Design of energy storage systems and energy supply systems are some of the important parameters for a proper operation of ZEB. At the same time, operation parameters and occupant behavior may significantly change the performance of the ZEB buildings. Therefore, in this study a demo ZEB building located in Larvik, Norway, was analyzed with respect to the plant operation and occupant behavior. This study examined an integrated solution of the building energy supply system consisting of flat plate solar thermal collectors (STC) in combination with a ground-source heat pump (GSHP) and an exhaust air heat pump (EAHP) for the heating and cooling, and production of domestic hot water (DHW). Photovoltaic were used to provide electricity for the house. The main feature of this building was that the majority of the energy demand should be covered by renewable energy sources available on site. The excess solar heat was utilized to recharge the borehole. The EAHP supplied thermal energy to the DHW storage tank; and cooperates with solar energy in order to preheat DHW. The ventilation air was heated directly from the ground-source heat exchanger. The entire building and integrated energy supply solution were simulated in IDA-ICE. To analyze occupant behavior, hot tap water use, set point temperatures, and equipment use were analyzed. Standard values and different scenarios based on the literature review were tested to examine different occupant behavior. Simulation results and field measurement from the demo house were compared to identify occupant behavior. The results showed that the total specific energy demand was 35.5 kWh/m2. The specific heating demand for the SFD was 27.1 kWh/m2, which was higher than the passive house standard. The system’s total annual solar fraction for heat was 35.9 %. This results showed that 85 % of the total heating demand was covered by renewable energy. The solar energy generated by the system could cover 85-92 % and 12-70 % of the DHW demand in summer and winter respectively. In addition, the solar energy may cover 2.5-100 % of the space heating demand. The results showed that the supply air volume, supply air and zone set point temperatures influenced mostly the total energy use. Approximately 3.6 % of electrical energy could be saved by reducing the supply air and zone set point temperature from 20°C to 19°C. Approximately 4.2 % of the electricity use was decreased by reducing the supply air flow rate from 1.2 to 1.0 m3/h·m2 floor area. This conclusion might be similar for similar buildings on different locations.

ABSTRACT. Increasing complexity of building energy systems has led to a wide range of methods to minimise cost of meeting demand for all types of energy. Metaheuristics and mixed integer linear programmes (MILP) are the two most prevalent optimisation methods in the field, with relative advantages which have not previously been compared under common criteria. The principle objective of this paper is to scrutinise these two optimisation methods when applied to a problem of finding the optimal operational schedule of an energy system serving a hotel. 11 technologies are modelled by both methods, but all exhibit nonlinear characteristics which must be linearised for use in MILP. Comparison of the two models results in variation between objective function below 1%, where piecewise linearised MILP gives the most optimal solution. The time to solution varies by orders of magnitude between models: 0.08s for simple linear MILP, 1.64s for piecewise linear MILP and 274s for metaheuristic. System designers, or controllers, must decide between solution time and realistic representation of technologies when choosing an optimisation method, a compromise which may be balanced by piecewise optimisation. Further, Proposed operation schedules vary slightly between methods, allowing some subjectivity in exact operation schedule, without compromising objective function. Metaheuristics favours qualitative subjectivity, while MILP favours quantitative subjectivity.

ABSTRACT. INTRODUCTION Variations in energy use of buildings are considered a significant issue towards their integration in the overall energy grid. Especially in the framework of Energy Hubs (1) where integrated district energy systems are dominant, the accurate prediction of the operational energy use of a building or clusters of buildings is crucial. According to the findings of IEA EBC Annex 53 (2), these variations are mainly attributed to the following areas: building envelope and equipment, operation and maintenance, occupant behavior and indoor environmental conditions, as well as climate. Starting from this classification, this study will treat these areas as a) the passive parameters mainly representing the building envelope and possibly the equipment and b) the active components standing for users and climate. Uncertainty characterizes both categories of parameters, especially occupancy. Uncertainty analysis has proven to be the main approach to determine the effect of uncertainty on building energy performance. Moreover, sensitivity analysis is conducted to analyze variations in building parameters and their effect on energy use. Previous studies have extensively used sensitivity analysis in building energy analysis such as (3), (4). Generally, the methodologies found in literature are classified into local and global sensitivity analysis (i.e. regression, variance-based, screening-based and meta-model based method). The first methodology is the most commonly used for building energy analysis, while the second one considers the interactions among the input parameters. METHODS The present study aims first at identifying the parameters that are responsible for the variations in energy performance investigating simple building models. Secondly, through the implementation of a sensitivity analysis, it will determine the key variables that affect energy use in residential buildings and propose a new methodology for parameter optimization. RESULTS AND DISCUSSION The derived results will be evaluated based on a reference model. It is discussed whether the levels of detail of each building parameter is necessary to accomplish accuracy. CONCLUSION The results of this study lead to a methodology for realistically estimating the magnitude of key variables on building performance. The next step will be to apply this methodology to housing stock models in future studies considering any sources of uncertainty, such as heterogeneity and parameter uncertainty.

REFERENCES 1. M. Geidl and G. Andersson, ‘Optimal Power Flow of Multiple Energy Carriers’, IEEE Transactions on Power Systems, 2007, 22: 145 – 155. 2. IEA EBC Annex 53, Final Report, ‘Total energy use in buildings’, November 2013. 3. A. Ashouri, F. Petrini, R. Bornatico, M. J. Benz, ‘Sensitivity analysis for robust design of building energy systems’, Energy, 2014, 76: 264-275. 4. P. Heiselberg, H. Brohus , A. Hesselholt, H. Rasmussen, E. Seinre, S. Thomas, ‘Application of sensitivity analysis in design of sustainable buildings’, Renewable Energy, 2009, 34:2030–6.

ABSTRACT. INTRODUCTION Building energy use is a significant driver of environmental emissions. Efficient building design, optimal selection of components, and efficient operation are potential ways of reducing overall demand. Achieving reductions in demand is a key directive of the net zero energy building (NZEB) concept. Building designs dedicated to meeting NZEB requirements are becoming more common as a path towards reducing the overall emissions from the built environment. This work analyses the energy demand of a case study NZEB and compares it with a more standard modern building. Through analysis of energy use, the effectiveness of efficiency measures incorporated in the case study building is evaluated and the results are provided.

METHODS Energy data from two case study buildings – one NZEB, the other a modern standard commercial building – was analysed. Both buildings are situated on the same site and the data used for comparison is from the same time period and weather conditions. Energy consumption on sub-system and whole-building levels were compared between the buildings on a per m^2 floor area basis.

RESULTS Total energy use intensity for the commercial building for 2015 was measured as 142 kWh/m^2, while the total yearly energy use intensity of the NZEB was projected to be 45 kWh/m^2 – 3.1 times lower than that of the commercial building. Calculated lighting power density (LPD) for the NZEB and the commercial building was approximately 1.6 W/m^2 and 8.0 W/m^2, respectively. HVAC loads in the commercial building are more constant but are marginally smaller in winter. HVAC loads of the NZEB peak in winter and are similar to that of the commercial building. Significant savings in HVAC loads of the NZEB are found outside of winter, where natural ventilation reduces the need for artificial heating or cooling. Analysis of the time spent outside a reasonable comfort band at the NZEB shows that the HVAC system is able to perform generally well whilst consuming only 45% of the energy of the conventional commercial HVAC system.

DISCUSSION The results presented here represent NZEB performance in a mild climate, and would differ for more extreme conditions. The climate in this location aligns with a reasonable occupant comfort band, allowing natural ventilation to work successfully within the NZEB. The reliance of the NZEB on natural light means that the LPD can be 5 times lower than the commercial building. This is also a function of building design which allows large amounts of light into the building. Results also show that NZEBs are more sensitive to changes in design than conventional commercial buildings. Controlling artificial light according to available daylight has the potential for significant energy savings, depending on the building design.

CONCLUSIONS Measurements and analysis undertaken illustrate the effectiveness of NZEB concepts for the reduction of energy use. Natural ventilation in mild climate zones can achieve significant savings when implemented in HVAC strategies. Low lighting power densities and daylight harvesting can cut lighting energy consumption significantly. However the building envelope and layout must be properly considered to ensure success.

ABSTRACT. Energy use in buildings accounts for a large part of the energy use globally, and as a result of this, international building energy performance directives are becoming stricter. This trend has led to the development of zero-energy and plus-energy buildings. Some of these developments have led to certain issues regarding thermal indoor environments, such as overheating. Thermal comfort of occupants should not be sacrificed for energy efficiency but rather these should be achieved simultaneously. Although the priority should be to minimize the cooling demand during the design, this is not always achieved and cooling might be needed, even in residential buildings. This paper focuses on the cooling operation of a detached, single-family house, which was designed as a plus-energy house in Denmark. The simulation model of the house was created in IDA ICE and this model was validated with measurement data in a previous study. The effects of cooling demand (internal vs. external solar shading), space cooling method (floor cooling vs. air cooling with ventilation system), and the availability of a nearby natural heat sink (intake air for the ventilation system being outdoor air vs. air from the crawl-space, and air-to-water heat pump vs. ground heat exchanger as cooling source) on system energy performance were investigated while achieving the same thermal indoor conditions. The results show that the water-based floor cooling system performed better than the air-based cooling system in terms of energy performance and also regarding the energy use of auxiliary components such as pumps and fans. The integration of natural heat sinks into the cooling system of the house results in significant energy use reductions. The coupling of radiant floor cooling with ground enables to obtain “free” cooling, although the brine pump power should be kept to a minimum to fully take advantage of this solution. The cooling demand should be minimized in the design phase as a priority and then the resulting cooling load should be addressed with the most energy efficient cooling strategy. The floor cooling coupled with a ground heat exchanger was shown to be an effective means to minimize the energy use for cooling purposes, and this can contribute to achieving zero-energy or plus-energy targets in future buildings.

ABSTRACT. The focus on the indoor environment and the energy use in buildings is increasing which sets higher standards for the performance of HVAC systems in buildings. The variety of available heating systems for both residential buildings and office buildings is therefore increasing together with the performance of the systems. This paper reports the results of a simulation study carried out using the commercially available building simulation software IDA ICE. The considered house was designed as a plus-energy house and it was located in Denmark. The building simulation model has been validated and calibrated with the measurement data from the actual house in a previous study. The studied systems were radiant floor heating, warm-air heating through ventilation system and radiator heating. The energy performance of systems for achieving the same thermal comfort levels was compared. The effects of several parameters on system energy performance for each space heating solution were investigated; floor covering resistance of the floor heating system, having a heat recovery on the exhaust in the ventilation system, and different working temperature levels for the radiator heating. For all cases the heat source was a natural gas fired condensing boiler, and for the floor heating cases also an air-to-water heat pump was used to compare two heat sources. The systems were also compared in terms of auxiliary energy use for pumps and fans. The results show that the floor heating system had the best performance in terms of energy and it can be coupled to other heat sources than a boiler. The floor covering resistance of the floor heating system should be kept to a minimum to fully benefit from the low temperature heating potential since an increased floor covering requires higher average water temperatures in the floor loops and decreases the COP of the heat pump. The water-based heating systems required significantly less auxiliary energy input compared to the air-based heating system. The results show that low temperature heating systems, as in floor heating in this study, can contribute to achieving plus-energy targets by minimizing the energy use for space heating purposes while achieving necessary thermal comfort for the occupants.

ABSTRACT. EMBRACE was designed as a plus-energy house of two storeys (59 m2 floor area), protected by a large glass envelope (referred to as the “weather shield”) which integrates photovoltaic panels (2.85 kWp operational during the studied period). An unconditioned sheltered garden occupies part of the space below this weather shield, and is therefore protected from rain and wind. EMBRACE is located in a thematic park open to visitors in Nordborg, Denmark where it is undergoing a year-round monitoring campaign. This study focuses on the evaluation of its performance in terms of indoor climate and energy, between June and September 2015.

The house’s structure is divided in four modules and its envelope is highly insulated with a U-value of 0.08 W/m2K for the walls. EMBRACE is equipped with a dry-radiant floor system, covered with ceramic tiles, and which is the main source of heating and cooling to the space. A reversible air-to-water heat pump produces the heated or chilled water which is stored in a tank before its use by the radiant floor. Mechanical ventilation with active and passive heat recovery is also installed in the house.

The house was in cooling mode during July and August, with a set-point of 24°C for the radiant floor system, and in heating mode during the rest of the studied period, with a set-point of 20°C. Mechanical ventilation is set to a constant air change rate of 0.7 h-1 for the sole purpose of providing fresh air. The occupancy is not controlled since the ground floor can be visited by the public during opening hours of the park; the access to the first floor is however prohibited to the visitors. Operative temperature is measured on the first floor at 0.6 and 1.1 m heights, air temperature is measured in three different locations of the house as well as in the sheltered garden. A weather station placed on the roof records the outdoor conditions.

The house showed satisfactory results in terms of indoor thermal environment: the operative temperature was above 26°C for 58 hours on the first floor and for 15 hours on the ground floor during the four studied months. Indoor climate Category II of EN 15251 was met during between 66 and 82% of the time during the cooling period, and between 86 and 100% of the time during the heating period. Overheating did not result to be an issue, but the operative temperature sometimes dropped below the heating limit of 20°C even in summer. This was caused by a combination of door openings by visitors and cold outside weather conditions. Even though the sheltered garden was not closed, the air temperature in this space was frequently 2 to 3°C higher than outdoors, increasing the possibilities for comfortable occupancy. The energy balance between the HVAC system’s consumption and the PV production proved to be positive, with a consumption of around 333 kWh and a production of 1563 kWh during the considered four months.

ABSTRACT. Buildings account for around 40% of the final energy consumption in Europe and are central in the work towards increased energy efficiency. In order to plan and perform effective energy renovation of the buildings, it is necessary to have adequate information on the current status of the buildings in terms of architectural features and energy needs. Unfortunately, the official statistics do not include all of the needed information for the whole building stock.

This paper aims to fill the gaps in the statistics by gathering data from studies, projects and national energy agencies, and by calibrating TRNSYS models against the existing data to complete missing energy demand data, for countries with similar climate, through simulation. The survey was limited to residential and office buildings in the EU member states (before July 2013). This work was carried out as part of the EU FP7 project iNSPiRe.

The building stock survey revealed over 70% of the residential and office floor area is concentrated in the six most populated countries. The total energy consumption in the residential sector is 14 times that of the office sector. In the residential sector, single family houses represent 60% of the heated floor area, albeit with different share in the different countries, indicating that retrofit solutions cannot be focused only on multi-family houses.

The simulation results indicate that residential buildings in central and southern European countries are not always heated to 20 °C, but are kept at a lower temperature during at least part of the day. Improving the energy performance of these houses through renovation could allow the occupants to increase the room temperature and improve their thermal comfort, even though the potential for energy savings would then be reduced.

ABSTRACT. Research on thermal comfort in residential houses in Indonesia was limited. Previous researches in this field indicate that the western thermal comfort standard (ASHRAE 55, EN 15251, ISO 7730) was not adapted to Indonesian people due to different historical experience of climate. For this reason, the present study attempts to develop a new predictive thermal comfort standard which will be suitable for Indonesian people. This standard aims to provide minimum requirement for acceptable indoor thermal environment. On the other side, in order to get feeling of comfort, Indonesian people now tends to use mechanical fan or air conditioner to provide more cool environment. This study proposed a solution not only to reduce the energy consumption but also to present thermal comfort by developing a passive house standard for the tropical climatic country, Indonesia. This paper present the initial stage of the project by investigating current climate in Indonesia, current typical house characteristics, thermal comfort and household electricity consumption. Data collection from 18 houses in Depok (West Java) was done in August and September 2015. Result of data collection from eighteen households shows the electricity consumption for cooling was the second highest among all the consumption (16-25% of total consumption). Higher temperature was obtained at noon up to 35oC/32oC for outdoor/indoor, and the lowest relative humidity occurred up to 44% in outdoor. Data regarding the current typical house show that the wall material widely used is low bricks which are cheaper than brick, and floor and tiles material are ceramics and tiles respectively. In addition, most of windows is casement with ray ban glass which had a capability to block sunlight. In this current climate and house characteristics, 4 times/day data (morning, noon, evening, night) with 7-point thermal sensation scale on thermal comfort for 36 respondents were collected for a week during they stay at home. Percentage distribution of the votes shows the most comfortable (votes 0) time at home was in the morning (88% respondents). At noon, 52.6% of respondent feel warm and 12% feel hot. In order to know the standard comfort temperature for Indonesian people, the regression analysis was developed based on this data. The regression line showed that the normal temperature was 27.6oC. This result was almost the same as several previous researches in Indonesia and it possibly be used as a comfort standard for Indonesian people and as a guideline for designing passive house. Finally, current energy consumption in these residential houses figures out that the total energy needs was generally between 300-400kWh/month which should be reduced as much as possible.

ABSTRACT. INTRODUCTION This investigation presents a detailed analysis in an effort of building energy performance improvement from the aspect of building envelope and glazing influence on the annual heating and cooling energy demand. The research was conducted on a reference office building which is part of the Faculty of Technical Sciences complex in Novi Sad, Serbia. Our previous investigations cover building envelope optimization in the function of indoor daylight quality in offices in order to determine preferable window to wall ratios and window geometries. This work is the continuance of the envelope optimization investigation and elaborates the influence of five different glazing types on the annual heating and cooling energy demand of the reference office building in compliance with energy efficiency regulations.

METHODS AND MATERIALS Detailed numerical simulation in Radiance engine was applied in the envelope glazing optimization phases (overview of the previous research). The overall energy performance of five multi-level office building models (tot. area 3430m2) was simulated in EnergyPlus engine. Factors influencing the energy demand were modeled together with the various glazing types. Energy demands were determined according to the energy efficiency regulations of the building construction’s thermal performance. Total energy expenses for district heating and electricity were gathered from the year 2013 in order to compare them with the simulated results. The location and climate data for Novi Sad city were imported from the global climatological database Meteonorm (~150 000 parameters, 15min intervals).

RESULTS A comparative analysis was performed among the gathered annual building expenses and simulated heating and cooling demands from the multi-zone thermal model constructed in EnergyPlus engine. Findings from the dynamic simulations indicated the influence of glazing parameters (U-value, Solar heat gain coefficient) on the annual heating and cooling demand of the multi-zone building model. It was determined that the heating energy demands are highly influenced by the characteristics of the windows. Also it was assessed that the solar heat gain coefficient is crucial since it has: • Major influence considering external solar energy gains and • Indoor energy gain maintenance from internal heat sources. The U-value did not take a crucial part in the influence of the heating and cooling demand. The energy demand for heating according the findings could be reduced by more than 60% on annual basis compared to the reference building.

CONCLUSION The investigation presents the significance on the reduction of annual energy performance of building envelope’s thermal properties and the application of adequate windows in the function of climate conditions, building type and compliance to energy efficiency regulations. The formulated integral method could be applicable in building envelope improvement of existing office buildings and for new projects respectively, in order to indicate methods of efficient intervention for envelope improvement and to offer architects and engineers useful information during decision making process.

ABSTRACT. Introduction: Energy efficiency in buildings is a priority for energy policy at EU level and important legislative initiatives are in place to increase the diffusion of high energy performance buildings in European building stock. However, the high cost for achieving energy efficiency, especially in the field of buildings construction and renovation, is an important barrier in individual investment decisions. This risks to increase the divide between advantaged and disadvantaged social groups, fostering vicious circles of social exclusions, precariousness and uncertainty on the future. Reducing fuel poverty is still a challenge in many Member States. Economical, technical and behaviour barriers still compromise the diffusion of affordable and sustainable buildings especially for young families, already affected by the economic crisis.

Methodologies/ study: The paper presents and discusses the main goals and criteria of a EU-wide Design Competition for an Affordable Positive House. The competition aims at challenging that positive energy buildings are luxury goods. This contest will serve as a catalyst for demonstration, showcase projects, innovative ideas to merge societal, economic and environmental goals in the field of building design and construction. Participants will be asked to provide innovative projects merging affordability, comfort/quality of life and energy performance, with in mind a specific family target (young family). Therefore a holistic approach to building design is required. A "positive energy building" is defined as a building that has high energy performance and that produces more energy than it consumes. Therefore, the energy goal will be achieved by using a combination of technologies which reduce energy requirements and on-site renewables energy production. An affordability criterion is fixed by the requirement of a cost minimizing approach towards maximum overall cost of 80000 Euros. The projects will be asked to comply with four major criteria that will be evaluated in the following contests: architecture, engineering, cost optimization, environmental sustainability, smartness and connectivity. The main criteria will include consideration about modularity and replicability of the construction elements as an important variable for the real chance to achieve a significant diffusion of energy efficient development in EU building stock. Proposed innovations will be evaluated as potentially ready for the positive residential housing market. Special focus will be given to the implementation of renewable energy sources in the projects as well as water footprint and minimisation of maintenance and operations costs of the construction.

Conclusion: The promotion of the widespread diffusion of positive energy buildings, and high energy-efficiency technologies, if not adequately balanced by economic concerns, may limit their diffusion to the most vulnerable social groups. It is important to stimulate architects, engineers and construction industry professionals to adopt innovative low-cost solutions to reach high energy performance, and a specifically targeted EU Design Competition have the potential to be a catalyst in this process.

ABSTRACT. The Passive house is one of the nearly zero energy housing system suggested by Germany. The PHPP, Passive House Planning Packaged, is a criteria which can turn the energy balance, passive house design into reality.

In these days, the topic of energy efficiency and saving problems becomes one of the most important international agenda. The green house gas emission in building industry in Korea is up to 24%. To reduce the green house gas emission, the Korean government makes an effort by planning the compulsory energy reducing in buildings. Until 2025, by offering the zero energy residential building, the target of reducing energy consumption in residential building can be accomplished. In this situation, the Passive house is up for discussion as one of the best solution to solve the the building energy problems. Also, some projects have been accomplished by the PHPP in Korea.

In this paper, the heating energy demand of the newly constructed single family house, general residential type in Korea, was analyzed by simulation method. And the results were compared with the passive house criteria (PHPP).

The results showed that the heating demand of the analyzed building was 56.05 kWh/㎡·year. Four times more heating energy is required in newly constructed single family house in Korea compared to the heating demand of passive house criteria(15 kWh/㎡·year).

Although, the analyzed building has higher performance in insulation compared to general Korean residential building, the heating energy demand is higher than that of Passive house criteria. In this paper, the reason why the analyzed building is needed higher heating energy demand than the Passive house criteria will be discussed. Also, the strategies for reducing the heating energy demand of the analyzed building as PHPP will be suggested.

ABSTRACT. Net zero energy buildings (NZEBs) have been widely considered to be an effective solution to the increasing energy and environmental problems. Most conventional design methods for NZEB systems are based on deterministic data/information and have not systematically considered the significant uncertainty impacts. Consequently, the conventional design methods lead to popular oversized problems in practice. Meanwhile, NZEB system design methods need to consider customers’ actual performance preferences but few existing methods can take account of them. Therefore, this study proposes a multi-criteria system design optimization for NZEBs under uncertainties. In the study, three performance criteria are used to evaluate the overall NZEB system performance based on user-defined weighted factors. Case studies are conducted to demonstrate the effectiveness of the proposed method.

ABSTRACT. The following abstract is proposed to be presented as a Technical Session, in the Smart Building Operations and Maintenance topic of the Congress.

INTRODUCTION This paper presents a case study of the design of a sustainable facility in Canada’s high Arctic through the perspectives of the client, architect, and engineer. Sustainability in this context means more than just energy use. Successful integration into the host community, promotion of local participation in construction and operation, and remote monitoring of system performance were some of the goals that required close collaboration between all stakeholders. The Canadian High Arctic Research Station (CHARS), located in Cambridge Bay, Nunavut, will help anchor a strong research presence in Canada’s north. An integrated design process was used to meet the objectives of supporting world-class, multidisciplinary science and technology research, integrating into the host community, and being a leader in green and sustainable technologies for the Arctic.

METHODS Canada’s high Arctic presents particular challenges to the planning, implementation, and operation of a building which are either not present in southern Canada or are less of a problem. Some of these challenges include energy and water costs that can be five to ten times more expensive than in southern Canada, lack of skilled workers, and a harsh environment. An integrated design process was used to ensure CHARS responds appropriately to these challenges, including community consultation and energy simulation. The process helped the client develop an approach that promotes participation by northern and Inuit-owned firms.

DISCUSSION Community consultations held with elders, youth, and other residents helped to identify the expectations of the community. It also helped the design team better understand how the building will impact the community’s resources, such as trucked water and diesel-based energy systems. For the client, these consultations helped inform approaches to promoting local participation in construction and operations, including requiring the construction manager to develop and implement an Inuit Benefits Plan. Energy simulations were conducted early and throughout the design process using a life-cycle cost analysis approach. This helped sustainable decision-making by the design team and helped the client understand the scope of operational costs. The integrated design process led to the conclusion that monitoring of water and energy consumption is crucial. This monitoring supports building commissioning, the quality assurance process that provides the client with confidence that the building will operate as intended. It will enable remote systems support and diagnostics. The acquired data will help the client in their efforts to use the facility as a ‘living laboratory’ for testing of new, sustainable technologies. Also, the design team realized during the workshops that data collection could become an important teaching tool for community members.

ABSTRACT. INTRODUCTION In Europe (EU) the building sector is responsible for about 40% of the final energy demand and 36% of CO2 gas emissions. The recast of the Directive on the Energy Performance of Building (EPBD) imposed the adoption of measures to improve energy efficiency in buildings in order to reach the objective of all new buildings to be nearly Zero Energy Building (nZEB) by 2020. Moreover, EPBD recast has set out that Member States (MSs) ensure that minimum energy performance requirements are set with a view to achieve the cost optimal level, that is defined as the energy performance level that leads to the lowest cost during the estimated economic lifecycle. Through the so-called cost optimal analysis (COA), based on Global Cost method, each MS should define the most effective strategies to improve building performance with the lowest global cost. Since 2010, many papers from different research groups and countries were published regarding different applications of the cost optimal methodology. After some years, there is the need of identifying the most promising technologies and methodologies for bridging the gap between the zero energy goal and the economic affordability. METHODS This paper analyze most of the applications of cost optimal analyses since the EPBD recast entered into force, in order to point out the different approaches and compare the results. The selected papers were classified according to the country of application, the type of building, the considered financial framework and the methods and tools that have been used for the selection of the energy efficiency measures and for assessing the energy performance of the building to which the different packages of energy efficiency measures were applied. RESULTS The performed analysis resulted in the identification of the main trends in the application of the cost optimal analysis for scientific purposes. In particular, the paper results focus on the methods used for solving the optimization problem related to the cost optimal search and shows how the method influences the results. The most used criteria for the manual selection of the packages of energy efficiency measures and the optimization algorithms in the automated procedures are investigated in their effectiveness. DISCUSSION A critical discussion about problems and advances of the cost optimal analysis is presented based on the review results. The results in terms of cost optimal levels and the related energy performance of the studied buildings show some differences, mainly due to the great amount of variables that makes the nZEB design strictly related to the local scale. At the same time, a shared vision on the most promising methodologies for the evaluation of the cost optimal level is emerging and is presented in the paper.

ABSTRACT. Depending on the Energy Performance of Buildings Directive; energy performance of an existing building is studied over simulation tools by calculating the whole building’s total energy consumption. This study compares the energy calculation results of Turkey’s national building energy performance simulation tool BepTR and a worldwide approved simulation tool, OpenStudio. Moreover, both simulation results are compared with the existing case building’s actual data. Ustundag Apartment located in İzmir, with a 90 m2 total area including the ground floor,4 upper floors. The apartment has one attached façade and 3 detached facades oriented to south-east, north-east and north-west. Regarding to the methodological differences of the simulation tools, the input and output data sets and monthly bills were collected for the 2nd floor flat whereas the heating and hot water demands are supplied by natural gas and the lighting and cooling demands by electric energy. In a preceeding study, the same methodology was used for a municipality office building and the comparison between the simulation results and actual data gave considerable differences. Subjecting to this interrogation point; a small scaled building with a single function and simpler mechanical system is chosen for this study. Within this study, the results energy consumption results gathered from the actual consumption bills and the simulation tools are interpreted over the simulation limitations. Consequently, the rstudy asserts that the ‘detailed dynamic methodology’ calculation results are absolutely approximate to the actual data whereas the ‘simple hourly dynamic methodology’ calculation results are dramatically differentiate.

ABSTRACT. European “Energy Performance of Buildings Directive - (EPBD) EU/2010/31” requires all new buildings in Europe to be nearly Zero Net Energy by end of 2020. As very efficient buildings are more and more common, there is a growing concern about the real performance achieved by these buildings once in operation. Indeed, it is often observed that supposedly “green” buildings consume much more than what was estimated in the design phase: this is the so-called “performance gap”. It is thus of prime importance to compare, each time this is possible, the real behavior of the building with the expectations and identify the causes of discrepancy if any, in order to correct the defaults and gain experience for future projects. The aim of this article is to present such a “real vs. estimation” comparison for the Woopa building, a recent positive-energy large office building in Vaulx-en-Velin near Lyon in France. The study relies strongly on the concept of “simulation calibration”. The idea is to adjust the building model used in the design phase so that the simulation matches well the actual behavior of the building. Four main steps were carried out. First, a target simulation model was created, using the EnergyPlus simulation program. Second, the building BMS data of the third year of operation were analyzed with advanced data analytics techniques in order to understand the actual occupation and HVAC schedules. Then, a calibration process was developed to match the real data with simulation output. Finally, a comparison between the target and the calibrated models allowed us to analyze the discrepancy between the performance target and the real building behavior. The calibrated simulation reached a satisfying precision with a relative Mean Bias Error (MBE) of -1% and a monthly CV RMSE of 5% (to be compared respectively to the 5% and 15% precision required by the ASHRAE Guildeline 14). The precision on temperature is also excellent, since the hourly RMSE over the year is 0,4°C. The study showed that the building actual consumption for 2013 (107 kWh of primary energy/m2) was relatively close to the target one (92 kWh of primary energy/m2). Most of the difference was due to the target model underestimation of the electric equipment consumption. The analysis also showed that AHUs were often not functioning properly with no ventilation during occupation, resulting in a degraded air quality in the building. The article eventually draws conclusions on the best practices for using BMS data and energy simulation for closing the performance gap and improving building day-to-day operations.

ABSTRACT. 1.INTRODUCTION Various optimization strategies have grown in popularity in air conditioning systems due to increasing concerns about the indoor comfort and building energy consumption. For HVAC systems, especially for thermal displacement ventilation systems (TDVS), spatial influence of the indoor environment is important to take into consideration because of the fully stratified air distribution. Many researchers use parametric studies or data-driven methods to achieve better performance of such systems, but the time-consuming problem and the generalization capabilities limit their applications. The development of more controls-friendly building simulation tools is helpful. Genopt and its developments have been used for various complex optimization problems. However, the algorithm interface only allows adding new optimization algorithms that is programmed in JAVA code. In addition, if the model file of the simulation program is considerably large, Genopt will become inefficient. In this study, we establish a kind of general optimization framework, which can couple any Matlab-based optimization algorithm into any text-based building simulation program.

2.METHODS The key part of this optimization frame is the data interactive mechanism, which is realized by C++ program. The interface module passes the independent variables from optimization algorithms to building simulation programs at the beginning of each iteration, and passes the related simulation results back to matlab for cost function evaluation. A general optimization problem using the proposed data interactive mechanism will be set up in four steps: 1, Construct a building model using simulation program; 2, Design an optimization algorithm using Matlab; 3, Set all the Input/Output files of the interactive module; 4, Run the searching procedure until the optimized control variables are obtained. A plenty of Matlab based algorithms are convenient to use for the proposed optimization scheme. Differential evolution algorithm (DE) is applied in this study for its simple structure and effective global optimization ability.

3.RESULTS To investigate the performance of above-discussed optimization scheme, a 3D office room equipped with TDVS is modeled using CFD tool Airpak3. The simulation model is validated by experimental data in advance. The target is to improve the thermal comfort, Indoor Air Quality (IAQ) and energy efficient of the office room. To cover all the issues under consideration, The following indicators are selected: 1) PMV for thermal comfort assessment, 2) CO2-based ventilation effectiveness for IAQ assessment, and 3) Energy demand for ventilation. Accordingly, the objective function for optimization is prescribed by aggregating and weighting the above indices into one equation J. To investigate the advantage of such optimization framework, we set up a baseline case for comparison. Optimal solution of the control variables is found, which improves thermal comfort, IAQ and energy cost in a balanced way. By the proposed framework, various of optimization problems can be easily performed by Matlab based methods regardless of the difficulty of cost function evaluation for complex PDE systems.

ABSTRACT. In a HVAC system, optimization is always adopted to improve the operational efficiency by finding optimal control settings and operation modes since a small increase in the operational efficiency may lead to substantial energy savings. As the HVAC system becomes more and more complex, the real-time optimization of the system becomes a challenge in practical applications due to the computational complexity. In current practices, almost all of the developed methods belong to the type of time-driven optimization, in which the optimization is driven by “time”, i.e. the optimization is performed at a fixed frequency. It is well-known that optimization should be done when the operational condition experiences a significant change, which may cause the current control settings or operation modes not optimal any more. Hence, “time” may not be the real driver for the optimization and the optimization with a fixed frequency may lead to unnecessary or delayed actions in practical applications. In order to overcome the limitation of the time-driven optimization, this paper proposes an event-driven optimization method, which originates from the recent development of the event-driven control in control engineering. The key idea is that, unlike the conventional method that uses “time” to trigger the optimization action, the event-driven method uses “event” as the optimization trigger. The “event” should be a well-defined condition, which can reflect the system state or the state change. Thus, optimization will be conducted only when predefined events happened. To investigate the feasibility of the event-driven optimization for HVAC applications, the computation load and the energy saving potential of the proposed method are compared with that of a conventional time-driven method using a simulation platform, which is constructed to simulate the 24-hour operation of a typical complex HVAC system in Hong Kong. The results show that the computation load of the proposed method can be greatly reduced (up to 90%) in comparison with the time-driven method without sacrificing the energy performance. The proposed method achieves an energy saving of 10.65% compared with the benchmark (in which no optimization is conducted), while the time-driven method achieves an energy saving of 10.01%.

ABSTRACT. Buildings account for about 40 % of national energy consumption, and hospitals represent about 6 % of the total energy consumption of public buildings in Norway. A large university hospital uses twice as much energy per square meter compared to other commercial buildings. Large university hospitals recently built in Norway have annual energy consumption between 300-400 kWh/m2. Hospitals have a wide variety of functional requirements, usage patterns and other operational challenges that determine the suitability of different technical solutions.

Rapid change in the usage of different function areas, without too much rebuilding or retrofitting, is possible by integrating the various technical installations. This integration enables the building to quickly adapt to changes in new and future-oriented hospitals. In most cases, a simple reprogramming is all that is required to reconfigure the technical systems to the new demands.

In order to optimize flexibility and total energy consumption, it is important that the various communication systems (bus systems) can communicate with each other (integrated communication). Building systems such as lighting, ventilation, cooling and heating, can then respond in a unified way to a common set of external demands such as presence detection, room reservation, fire/smoke detection, solar flux and so on. This approach allows customized management of each configuration. Integrating as many technical systems as are feasible within a building automation system is also likely to reduce the amount of cabling and the total investment cost for the installations.

Technical integration has four main categories: • Communication related to specifications in hospitals • Safety (secure) systems • Centralized technical systems • Specific functional area technical systems

A patient room is an example of an area with many different activities and needs for illumination throughout the day. The lighting requirements are different during normal stay, relaxation, examination, cleaning and recovery.

In an operating room the current procedure’s clinical requirements will determine the kind of medical equipment and other installations, the use of X-rays and monitors, the number of staff, and their task locations. All of the different cases must be considered when planning the optimal integrated system for an all-purpose operating room, including also the cases for cleaning and preparation of the rooms before the arrival of medical personnel and the patient.

We recommend using demand control (DC) principles in the design of systems for window shading, ventilation, lighting, heating and cooling to achieve the potential for energy and flexibility. We also recommend an interdisciplinary integration process early in the planning phase to ensure that most systems communicate on the same platform (bus-system); this will make it easier and overall less expensive to achieve good energy-efficient solutions. To get the right level of integration, it is important to analyze all the positive and negative aspects of integrating one system with another. Integration decisions for different technical systems should be verified by lifecycle cost analysis.

ABSTRACT. This study was conducted in a newly constructed office building in Norway in 2015. The office building is equipped with various air handling units (AHUs) that provide air to the different offices and meeting rooms for air quality and cooling purposes by means of variable air volume boxes (VAV-boxes).

In addition to integrated room automation (temperature, air quality and lighting) in the rooms, a state-of-the-art “demand based” controls approach has been implemented to operate the fans of the AHUs based on the position of the related VAV dampers. The Ventilation system has been designed by the HVAC consultant to support such a “demand based” controls approach right from the start.

The study clearly shows that the theoretical power consumption reductions at the fans due to this controls approach are achieved for real in this building. The data for the study has been gathered with the building automation (BA) systems own data acquisition functions (e.g. trend function).

This controls approach fully utilizes the means provided by the BA system and its communication networks between the rooms and the AHUs (in this case KNX and BACnet). Furthermore, no additional parts or installations were required to realize this “demand based” controls approach in comparison with traditional controls approaches such as e.g. constant supply/return air pressure control. The controls approach was easily implemented utilizing readily available standard and proven software solutions pieces of the BA system.

The study further reveals that because of this controls approach, the supply/return air pressure can be operated at substantially lower levels than originally (in the design phase) thought necessary, thus further reducing the power consumption.

To summarize the study clearly shows that by utilizing the “demand based” controls functionality and the communication means provided by the BA system it is easily possible to operate the AHUs – especially the fans – in this office building in a very energy efficient way, thus reducing the power consumption substantially compared to traditional controls approaches.

ABSTRACT. This paper presents an innovative energy concept, covering requirements for multifunctional office buildings, with the integration of geothermal energy and photovoltaic. This energy concept in combination with various extensions provides excellent demonstration opportunities addressing recent research topics. The energy concept bases on geothermal energy and heat displacement in connection with a heat pump process, a cogeneration plant, heat to cold shifting sorption-supported air conditioning units and photovoltaic. Concrete core activation and façade ventilation units distribute heat and cold base and peak loads within offices, displacement ventilation and active chilled beams supply conference spaces and laboratories. We added an extensive monitoring system, measuring the energetic flows of every energy source, energy conversion unit and energy consumer, as well as the thermal comfort conditions. Further, we transformed the building into a multifunctional demonstration bench for control research, enhancing the building automation system into a flexibly programmable and interface-able tool. Additionally, we developed dynamic simulation models for a variety of building components and validated them with gathered monitoring data. While drawing the building’s prospect on control research demonstration, this paper concludes with a specific use case of the application and demonstration of model-based control parameter fine-tuning.

ABSTRACT. Energy used by air conditioning and especially cooling is steadily increasing, and modernization of the technical systems is critical. The standard controllers must be replaced by novel and more efficient controllers. In the present article a model-predictive controller (MPC) called NeuroCool is presented, which features a self-learning building thermal model. In this article an overview of the algorithm and associated simulation / testing environment is provided; simulation results are analyzed to assess the performance of the algorithm. It is shown that when benchmarked against a standard controller, exploitation costs can be reduced by about 11% under similar comfort. If the comfort is lowered, but maintained within the tolerable norms, exploitation costs can be further reduced by 75%.

ABSTRACT. Built2Spec brings together a new and breakthrough set of technological advances for self-inspection and quality assurance that will be put into the hands of construction stakeholders to help meeting EU energy efficiency targets, new build standards, and related policy ambitions. B2S will expand upon a cloud based construction support platform, conceived following the most advanced integrated design and delivery framework for the building sector and hosting applications that facilitate worksite activities and quality compliance by putting knowledge in hands of contractors, in the form of shared design specifications and 3D models, installation guidelines, information on regulatory frameworks, and help from construction experts on smartphones and tablets. New self-inspection technologies managed within the platform and developed in the project include: • Special IR camera in smartphones coupled with new mathematical “reverse” models for on-the-fly analysis of existing buildings envelope thermal properties • Rapid BIM modelling via instant 3D capture with smartphones, passed via the cloud to the refurbishment team backoffice, allowing accurate instant energy efficiency evaluation, quality check and streamlined quotation process • Portable, innovative low pressure air tightness technique allowing testing of occupied buildings • Smart sensor-embedded construction elements (identification, structural performance, and building environment parameters) • Portable single device for Indoor Air Quality tests offering multi-gas capabilities targeting the most harmful gas pollutants • A novel lightweight portable sound source for on-site acoustic tests to regulation compliance The B2S system will be integrated into the operations of SME contractors, large construction firms, and end user clients directly within the consortium and work program activities, assuring systematic and scientific performance measures, feedback and powerful exploitation and dissemination strategies.

ABSTRACT. Toshiba is engaged in a smart community development project in Lyon, France, from 2011 to 2016. In the project, a Home Energy Management System (HEMS) will be introduced to achieve energy saving and comfort. The HEMS provides energy-saving functions that not only visualize energy consumption but also control preset temperature of thermostats operating valves by PID control. Since energy consumption tends to be high when preset temperature is high, it should be set at the lowest temperature compatible with comfort. Though obtaining a comfortable room temperature by means of a questionnaire was proposed, the task of completing the questionnaire would be burdensome for residents. This paper proposes a method of changing the thermostat preset temperature by estimating the resident’s comfortable temperature from motion sensors and thermometers. In the proposed method, which regards the duration of a temperature as a survival time, the resident’s comfortable temperature is estimated by survival analysis, a statistical technique, because the duration of a temperature is shorter when the resident feels cold. The procedure of the method is as follows. First, the method assesses whether the resident is in a room or not per minute from motion sensors. Second, the method obtains the temperature from a thermometer within a thermostat. Regarding rise in temperature as resident’s discomfort while the resident is in the room, the method models duration until the temperature changes with Weibull distribution. The method obtains each Weibull distribution from the duration of each temperature by survival analysis. Regarding the Weibull distributions’ parameters as features, the method classifies each temperature as comfortable or not in the feature space and sets the lowest temperature among those classified as comfortable as the preset temperature. We have evaluated the method for heating, using the data of five houses in Japan in five winter months. We have confirmed the estimated comfortable temperatures in winter approximately coincide with the result of a survey of the residents. The energy-saving ratio for heating was estimated to be 15.6%. The ratio of rooms where uncomfortable temperatures are mistaken for comfortable ones was 17.1%, i.e., six-sevenths of residents could accept the estimated temperature without experiencing any loss of comfort. We have also modified the method in order to apply it to the case where some residents are sensitive to cold and others are sensitive to heat in a room. Assuming that the duration of each temperature for each person is modeled by an individual Weibull distribution, we introduce Weibull mixture distributions. We also confirmed the comfortable room temperature is different for each person. By setting thermostat preset temperature at the lowest comfortable temperature estimated by the first method when there is at least a resident sensitive to cold in the room and at the lowest comfortable temperature estimated by the improved method when only residents sensitive to heat are in the room, we obtained a 1.1% increase in the estimated energy saving. Using this method, we have confirmed it is possible to decrease energy consumption while keeping comfort.

ABSTRACT. INTRODUCTON Due to the implementation of the European Performance of Buildings Directive (EPBD), the issue of energy efficient building operation is becoming more and more significant. Building automation and control systems(BACS) lead to considerable contributions, e.g. by improved and more sophisticated control algorithm or by running hardware-in-the-loop tests in the context of rapid control prototyping. In a hardware-in-the-loop (HiL) environment controller can be tested under predefined boundary conditions. HiL tools allow for example to configure and optimize control systems to the desired demand and energy efficiency.

RESULTS AND DISCUSSION At Biberach University of Applied Sciences there have been developed two HiL environments; one environment for the test of refrigeration controllers and a second one for testing room controllers. Each hardware-in-the-loop environment is composed of a dynamic simulation model of the controlled system (virtual process), a hardware coupling device and the real (physical) controller. For example, the room model consists of an amount of different room type models which can be configured with different parameters. In combination with different load profiles, weather data etc. it is possible to build up test scenarios which match the application conditions of the controller. The hardware coupling device provides an amount of digital or analogue physical inputs and outputs as well as interfaces to different bus and wireless systems. Hence a wide range of different room controllers can be coupled to the HiL system. Additional two different types of HiL systems were developed. A so-called Stationary HiL Environment enables a user specific and energy efficient development and parametrisation of automation systems. The so-called mobile HiL environment is constructed for a flexible utilisation in the field level. It supports operational test, error diagnostic and debugging of previously installed controllers. In the stationary HiL environment different controllers have already been tested under several conditions. Using the results different assessment criteria had been developed and tested in a practically environment. The mobile HiL environment has already been applied in two real rooms, in a seminar room controlled by a programmable logical controller (PLC) and a classroom of a school building attached to a central building automation system. In both applications some faults could be detected by logging and evaluating different data points by running the mobile HiL environment.

CONCLUSION Two flexible Hardware-in-the-Loop (HiL) environments for the design and test of building controllers were developed and tested in practice. In this environments controllers can be tested under predefined boundary conditions and also various controllers can be evaluated against each other. First practical applications show the eligibility of the HiL environments.

ABSTRACT. This study aims to develop different control strategies for application to nonlinear model of a thermal unit and compare their performances as an advanced thermal control methods for HVAC applications of sustainable buildings. The mathematical description of thermal unit was obtained exploiting a data-driven and physically meaningful nonlinear continuous-time model, which represents a test-bed used in passive air conditioning for sustainable housing applications. The presented controller strategies use both inside temperature and air flow control in the thermal unit. The proposed control schemes were assessed with extensive simulations and Monte-Carlo analysis in the presence of modelling and measurement errors. The contribution of this work consists of providing an application example of the design and testing through simulations, of a data-driven thermal unit control. Furthermore, this study provides an insight into different control strategies in air conditioning systems and helps the practitioners and HVAC learners to design proper controller solutions.

ABSTRACT. Fault Detection & Diagnosis (FDD) is at the heart of the European FP7 Performer Project that aims at reducing the gap between expected and actual energy performance. ENGIE joined up with the CSTB to deliver a FDD framework including a method based on expert rules. The purpose of the article is to both describe the methodology used within the Performer project and explain the benefits of such a method on building energy performance and users comfort. The main elements to build up such a method are the Key Performance Indicators defined for the project and the data measured on site (or expected to be measured) as they help identify needs and define the rules. Expert rules are based on operational key performance indicators, relevant to measure and verify the compliance between expected and actual performance. Among those expert rules, some of them are based on thresholds added to the user interface and can be flexible according to the level of energy performance to achieve. These thresholds represent expected values that are to be applied on specific pieces of equipment. When the actual value does not meet the expected one, an alarm is triggered. The method addresses any system in a building to detect a drift between actual and expected values; and can be applied online or offline. The methodology applied within the Performer project to the pilot sites follows several steps including data filtering, threshold definition, rules application and fault diagnosis. In the Performer case, the rules were defined on the basis of the needs expressed by the Building Manager of the French pilot site (the Woopa Office Building in Lyon) which can be considered as a positive energy building. These rules were applied, evaluated and optimized offline on a detailed set of data from the Woopa Building. There are several benefits of applying an expert rules assessment method. The first benefit of the expert rules method is its operational and practical convenience. It is very easy to apply and to use for any type of building. It usually addresses very technical and practical issues on site and therefore gives a very clear answer to the Facilities and Building Managers by providing an accurate picture of the systems’ performance level in their buildings. The FDD piece of work is on-going in Performer and the final results will be delivered after the publication of this article.

ABSTRACT. With global efforts to enforce various measures for energy reduction, South Korea plans to promote a zero-energy building mandate for all new buildings constructed after 2025. For this purpose, as of 2016, active research and construction work are underway to build an apartment complex with zero net energy consumption for 5 main types of energy use (cooling, heating, ventilation, hot water and lighting). As an inhabited residential complex, the apartment complex is expected to be available as rental housing for low-income families in the future. Constructing these zero-energy apartment buildings has the potential to save energy, however, it is still important for residents to recognize the proactive maintenance and management of the complex for zero energy consumption while residing in the complex. Aside from simple facility operations and malfunctions under facility management, there is a need for an efficient maintenance management plan for the people living in the apartment complex. The purpose of this study is to establish an efficient maintenance management plan for zero-energy apartment buildings. By deriving maintenance items that can be applied to domestic zero-energy houses through a comparative analysis of maintenance items from domestic and overseas green building standards and certification systems, we intend to develop the configurations of a maintenance management plan for zero-energy apartment buildings

ABSTRACT. As the smart building solution providers industry continues to mature, the benefits of deploying Building Energy Management Systems (BEMS) to achieve and sustain energy efficiencies goals within the real estate portfolio, becomes ever clearer. However as with any high volume data acquisition environment, BEMS are susceptible to a myriad of ongoing data integrity operational issues that beyond the obvious data outage reporting difficulties, can ultimately lead to a mistrust in the underlying data sets, and therefore a degradation in the value of any applied analytics that relies on the provisioning of accurate sensor or meter data. For example how does the smart building practitioner maintain confidence in a BEMS system accuracy and effectiveness, when there are unknown and undetected data outages, intermittent sensor or meter raw data reporting, or abnormal or corrupted sensor data events? Or how does the user become aware of a problem of sensor drift that may impact the BEMS reporting accuracy, and given the growing complexity of the sensor and metering environments, how does the user quickly fault diagnose the problem once it has been identified? These questions are critical to the notion of ongoing effective use of BEMS in an organisation, and so this paper attempts to address these known industry concerns, by setting out the background of the most important of these practical data integrity issues, by defining a data integrity validation methodology, and finally through a series of use cases, demonstrate how such an approach could effectively be applied, to build trust levels, by introducing detection and timely fault diagnosis in underlying BEMS raw data sources.

ABSTRACT. INTRODUCTION In order to reach the 20-20-20 EU-targets it is essential to increase the ambitions of the property owner´s to make refurbishment towards nearly zero-energy buildings. Most existing non-residential buildings have a potential to reduce energy use in a profitable way. A method called the Total Concept, has been developed and successfully applied on a large number of non-residential buildings in Sweden. The Total Concept method use a systematic approach throughout the whole building process of the energy retrofit, and includes functional performance checks and follow-up measurements the first year of operations. These experiences are systematically used to improve the quality of the Total Concept method. One relevant measure is to convert existing Constant Air Volume (CAV) to Demand controlled ventilation (DCV). DCV means systems that automatically regulate the ventilation rate according to a demand measured at room-level. The room ventilation rates are regulated with VAV-dampers. Studies show that energy use for ventilation purposes can be reduced by more than 50% with DCV compared to CAV.

METHODS The main methods are field studies, literature reviews together with simulations. These have been carried out in the R&D projects reDuCeVentilation (https://www.sintef.no/projectweb/reduceventilation/) and UPGRADE Solutions (http://upgradebuildings.no/). The results are improved with experience from control of new DCV-systems. The functional performance check is adapted to the IEE Total Concept project and fit the Total Concept method.

RESULTS and DISCUSSION Evaluation of real energy use demonstrates that DCV-based ventilation systems must improve their performance to close the gap between theoretical and real energy use. This unfortunate experience with DCV seems to have many causes, but the consequences are typically insufficient capacity at maximum load, or lack of controllability or precision at minimum air flow rates. The purpose of functional performance check is to reveal all kinds of inadequate performance within the full operating range of the air handling unit (AHU) and the VAV-dampers. The full operating range means from minimum load (typically empty building) to maximum design load for the AHU and from minimum (Vmin) to maximum (Vmax) for all the VAV-dampers. Functional performance checks carried out for these operating situations will reveal most types of inadequate performance.

CONCLUSIONS We recommend checking all the VAV-dampers with the Max-max-min and Min-min-max load tests. The Max-max-min load test is a functional test of the DCV system at the maximum airflow rate the AHU is designed for. Each VAV-damper is controlled for Vmax and Vmin at this load. The Min-min-max load test is a functional test of the DCV system at minimum airflow rate the ventilation system is designed for. Each VAV-damper is controlled for Vmin and Vmax at this load. This control test should be documented with a completed VAV control form.

ABSTRACT. New Campus of University introduces various advanced technologies to offer comfortable learning field and achieve a low carbon campus. To realize this target, setting of appropriate target and condition at planning phase and optimal design considering sufficiently how to use the facilities are required. At the same time, commissioning of performance is indispensable for the system to show an expected potential.　Under above mentioned background, the energy consumption, performance of heat source system and secondary side system and the indoor/outdoor environment are analyzed in this study. In this paper, energy consumption and CO2 emission of whole campus and performance of central heat source system for one year after beginning of operation were presented. This campus consists of the Lecture hall wing, the High building wing, Library wing, and the Refectory and Cafe wing. The site area is 23,000㎡. The total floor area is 33,132㎡ and the building area is 9,164㎡. And it is reinforced concrete structure and concrete structure, being a 10 story building. All wings have cool and heat pits to reduce outside air load. The Lecture hall wing has central heat source system, and the others have individual air conditioning system. In addition, Refectory and Cafe wing has the ground source and well water source heat pump. The central heat source system introduces cogeneration and consists of two waste heat input type absorption water cooling and heating machines and three air heat source heat pumps, making efficient use of waste heat and purposing the best mix between gas and electricity according to the heat load situation. As a result of first year operation, 1200tCO2 of CO2 emission of whole campus is lower than 1449tCO2 of the reduction target which is 0.69% of normal facilities. So it can be said that estimated low carbon effect is realized. Also according to the analysis of performance of heat source, the plan to improve the operation of heat source is proposed. Then the validity of the plan is evaluated by using system simulation.

ABSTRACT. Innovative control algorithms for HVAC are necessary if the rising costs associated with air conditioning and more specifically cooling are to be remain reasonable. In the present article we briefly describe such a novel model-predictive based controller, and the practical aspects of its deployment. We describe an implementation based on a MATLAB server, that allows a rapid validation. Then the test sites and associated analysis methodology are presented. Finally, the preliminary results obtained on these sites are presented and analyzed. It is shown that the proposed control algorithm is stable with respect to human disturbances and that comfort is controlled as desired. The communication and deployment architecture has been validated and has proven to work as expected.

ABSTRACT. Due to the rising auxiliary energy demand for the heat distribution in buildings alternative control strategies become necessary. The Unsteady State Floor Heating Project conducted at the Hermann-Rietschel-Institute at the Technical University of Berlin aims at developing a control strategy to reduce the pump energy demand for heat distribution while maintaining comfortable thermal conditions and short response times of floor heating systems. The project idea is to transfer the heat unsteadily by operating the circulation pump in a pulsed manner. By increasing the supply temperature of the heating system the median mass flow rate can be reduced. A dynamic simulation model is created in Modelica. Two typical floor heating systems are modelled - a conventional system with heating tubes installed in a counter flow spiral pattern and a state of the art capillary tube system installed in parallel tube pattern with a reduced concrete layer thickness. Different supply temperatures and mass flow rates are investigated concerning their applicability for an unsteady operation. Both systems are built up at the Institute’s thermal test facility to generate experimental results for the validation of the simulation model. The test facility consists of a test chamber and a climate chamber which can be cooled to around -15 °C. Both transmission and ventilation heat losses can be simulated. Inside the test chamber two office working places are installed to provide for realistic internal heat sources. To compare the energy usage of different operating points the specific energy demand is used. It is the quotient of consumed electric energy and transferred heat within the same period of time. With rising supply temperatures and decreasing mass flow rates the specific energy demand in both systems can be reduced by around 82 % at a supply temperature of 55 °C and a relative mass flow rate of 0.55 compared to the reference steady state operation at a supply temperature of 35 °C and a relative mass flow rate of 1 (nominal mass flow rate of 330 kg/h). The uncertainty of the measured specific energy demand ranges between ± 1.6 %. After a cool down period simulating the absence of the users the time to increase the operational temperature inside the test room is measured. The time to increase the operative temperature from 18 to 22 °C can be reduced by a factor of up to approx. 4.6 using the capillary tube system and by a factor of up to approx. 2.6 using the conventional tube system at a supply temperature of 55 °C. The maximum floor temperature exceeds 29 °C (normative requirement) during few minutes of unsteady state operation using the capillary tube. It does not exceed 29 °C using the conventional system. The results show promising applicability in systems demanding short response times or systems providing supply temperatures higher than those usually applied for floor heating systems, e.g. during renovation of old buildings. However, the maximum floor temperature has to be limited. Extending the control strategy to achieve this goal will be part of the further investigations.

ABSTRACT. INTRODUCTION: Simultaneous heating and cooling demand occurs frequently in office buildings. A four-pipe system is the traditional approach to deal with this situation as it has the ability to provide cooling to one zone and heating to another zone at the same time by operating two separated water circuits. Previous studies conducted by the authors investigated the energy performance of a novel HVAC system that enables simultaneous heating and cooling of office buildings by transferring energy between zones with one water circuit. The system was modelled by using traditional building performance simulation tools. However, these tools did not have capabilities enough to develop a detailed model of the novel system. This article aims to create a detailed model of the novel HVAC system by using Modelica. In addition, a simulation case study compares the energy performance of the novel system with a traditional system.

METHODS: The main characteristic of the novel system is its ability to provide simultaneous heating and cooling by having only one water circuit. Therefore, the same supply water temperature is delivered to all the thermal zones in the building, no matter whether a single zone needs heating or cooling. The system was modelled by using Dymola, a simulation environment based on the Modelica language. Basic elements of the Modelica Buildings library were used. Two office rooms with different thermal loads were modelled and connected to the system. Standard internal gains and construction thermal properties were selected. The system integrated a constant air volume ventilation system with supply air temperature of 20 °C. The water circuit was designed to operate with a constant supply water temperature of 22.5 °C for both heating and cooling mode. Active beams were integrated into the system as terminal units. In order to demonstrate the energy savings potential of the novel system, a simulation case study was performed. The novel system was compared with a traditional HVAC system. Heating, cooling and ventilation loads were calculated by the program and a weekly energy comparison was done.

RESULTS AND DISCUSSION: The use of Modelica as modelling tool allowed to overcome the limitations occurred while using traditional building performance simulation programs. Simulations with Dymola showed that novel system presented a weekly energy use of 64.5 kWh while the traditional system 75.5 kWh. As a consequence, the novel system used approximately 14.6 % less energy than the traditional system to maintain the same indoor air temperature in the office rooms.

CONCLUSIONS: A detailed model of a novel HVAC system for office buildings was developed with Modelica. The results showed that novel system has potential for saving energy by transferring energy between spaces when simultaneous need of heating and cooling occurs in different thermal zones of the building.

ABSTRACT. A large part of the auxiliary energy for cooling and heating systems in buildings is needed for the pumps that distribute the heat transfer medium in the thermal distribution network. A number of nature’s developments such as evolutionarily optimized shapes, drag reducing surfaces and additives have not so far been widely used for thermal distribution networks. The BioNet-project at the Hermann-Rietschel-Institute in Berlin aims at adopting promising solutions to this specific application and evaluating potential energy savings in domestic thermal distribution networks. Based on the typical technical conditions in domestic heating systems, a catalogue of applicable bionic developments was compiled by the project partner from the bionics institute. Numerical simulations (CFD) are used to adopt and evaluate the approaches to heating and cooling nets as well as to explain the physical principles of the bionic developments. In a hydraulic net, only the critical path, which is the path with the highest pressure loss, needs to be improved. About 10 % of all pressure losses are due to the bends and T-pieces. An evolutionarily optimized bend shape was developed that reduces the pressure losses by about 20 % in comparison to the conventional bend. The shape can easily be manufactured and the connection geometry of the conventional fitting is preserved. Due to the low pressure loss of single components, it is commonplace that this small measured quantity has an uncertainty in the range of 20 %. A more accurate assessment is necessary in order to reliably compare the designs. A new hydraulic test rig for the exact determination of pressure losses was therefore constructed. It features an elevated tank for the generation of a constant head and flow rate and utilizes a gravimetric measuring principle to determine the flow rate. A more hands-on board test rig was also constructed. The board test rig includes a small piping circuit with ten bends. The components in this circuit are exposed to rather complex flow conditions compared to the ideal conditions of the aforementioned test rig for testing a single component. This enables a direct comparison between a classic and a new bionic net. Rapid prototyping (3D print) was used to manufacture the new optimized fittings which were then tested on both test rigs and compared to classical fittings. The performance of the new shape is demonstrated by numerical simulations, high precision single component pressure loss measurements and in a practical test case for a demo piping circuit with ten bends. The new geometry is applicable to all typical conditions in heating nets (temperature, flow rate, and diameters). It has a simple geometry so that producing it is suitable for mass production with minimal additional costs.

ABSTRACT. The climate in Japan is hot and humid in summer therefore sensible and latent heat load should be processed and efficiently. Temperature and humidity independent control (THIC) of air conditioning system treat sensible and latent heat load separately. For latent heat process, most of the THIC systems employ desiccant dehumidification; hygroscopic agent removes moisture in the air and dried air is supplied to rooms. Desiccant dehumidification does not require low chilled water temperature which is used for condensation dehumidification. However, heat is necessary to regenerate the hygroscopic agent which contains moisture. In many cases heat source such as exhaust heat of combined heat and power (CHP) or solar heat will be appropriate for that purpose.

In this study, efficient operation of the system including THIC with desiccant dehumidification is explored by using static simulation. The system consists of CHPs, solar thermal collector, thermal storage tank, gas-fired absorption water chiller boiler (absorption chiller) and desiccant air handling system. CHPs and solar thermal system are connected in parallel. The mixed hot water from them is supplied to absorption chiller and then regenerative heating coil for desiccant air handling unit in cascade, which is called as hot water cascade utilization in this study. In summer, whole system performance is mainly dominated by efficiency of the absorption chiller system therefore temperature of chilled water and cooling water are the important factors. In this simulation, the effect of chilled water supply temperature and lower limit of cooling water temperature on the performance is examined.

Simulation is conducted with LCEM tool which has been developed under supervision of Ministry of Land, Infrastructure, Transport and Tourism. From the system simulation result, when chilled water is set at 7°C, the mixed hot water temperature becomes stable at around 80~85 °C. On the other hand, the mixed hot water temperature becomes stable at around 75~80°C when chilled water is set at 12°C. This difference results from the heat balance between heat supply side (CHPs and solar collector) and heat demand side (absorption chiller and regenerative heating coil) in hot water cascade utilization.

High cooling temperature results in high temperature of absorbent and decrease of temperature difference between absorbent and mixed hot water. Absorption chiller requires higher temperature of mixed hot water in order to maintain heat balance between supply and demand side in hot water cascade utilization. From the view point of solar heat utilization, higher chilled water temperature and lower cooling water temperature is preferable.

Simulation was conducted for the chilled water temperature of 7, 10, 12°C and the lower limit of cooling water temperature of 26, 28, 30, 32°C. The chilled water temperature of 7°C and lower limit of cooling water temperature of 32°C is referred as base case. As a whole system, case with 12°C of chilled water and 28°C of lower limit of cooling water is the most efficient in terms of coefficient of performance. However, the impact on whole system is relatively small and maximum increase is only 3% compared with base case.

ABSTRACT. Introduction The hydronic balancing of radiators is a cost-effictive method to reduce, on the one hand, the fuel consumption of temperature sensitive heaters and, on the other hand, the pump energy consumption. However, it is quite complicated and a lot of companies have developed methods to simplify it. Up to now, the solutions mainly focus on radiators (or floor heating systems respectively). Figure 1 shows a distribution manifold for 3 heating circuits each with a circulation pump and a mixing valve. The radiators are balanced but the heating circuits are not. The heat demand of the heating circuit on the left is not fulfilled and the heating circuit on the right makes noise because the flow rate is too high. As the circuits interact, because of the heat losses of the heater circuit, it is not possible to balance the whole system without additional equipment. The self-controlled pumps react in a wrong way. Usually, mechanical differential pressure regulators have been used to balance the heating circuits. But, they increase the energy consumption of the pumps during the whole heating season. The HeatBloC MC The new procedure describes an electronic differential pressure regulator. The differential pressure between flow and return line is measured and a high-efficient circulation pump is controlled via a PWM-signal. The comparison of both technologies is presented in Figure 2. With the mechanical differential pressure regulator the control curve of the pump has to be set very high. In nominal operation the pump consumes 28 W. The nominal flow rate occurs only a few times in the winter. So, in the course of a year a big amount of the pump energy consumption is dissipated in the controller. The electrical differential pressure regulator doesn’t add further pressure losses to the system. That is why it consumes only 20 W at its peak value at nominal flow rate in parallel operation. In opposition to the state of the art, there is a control area for the pump. It modulates its power consumption in relation to the heat demand. The overall energy savings of course depend on the pressures losses of the heater circuit and the frequency of the heat demands in the heating circuits. On the basis of TRNSYS simulations of a multi-family house in Zurich both technologies are compared and the energy savings are presented. The effect of different specific heat demands is assessed.

ABSTRACT. This paper describes the requirements stated in ErP (Eco Design) Directives 2009/125/EC, and implications of ErP legislations.

While the old EuP (former Eco-Design Directive) Directive was covering products that directly used energy, the new ErP Directive (replacement of EuP Directive) covers all energy using and energy related products (the products that do not directly use energy but effect the use of energy such as insulation materials).

ErP Directive was aimed to be a famework for reduction of energy consumption of covered products from the design stage throughout production, transport, packaging and so on. Products that comply with this directive are authorized to carry the CE marking. The CE mark covers energy efficiency requirements as well as product safety requirements.

ErP Directive is divided into lots that covers various groups of products. AHUs are grouped into Lot 6: Air Conditioning and Ventilation of directive. Electric motors and fans are grouped into Lot 11: Electric Motors (IEC) Regulation 640/2009, Fans Regulation 327/2011.

In this paper, requirements for conformity of AHUs and related components with ErP Directive, implications of related ErP legislations and energy labeling standards will be presented.

ABSTRACT. By comparison testing, this paper obtained the energy-saving rate of 12 buildings which had been reconstructed for energy saving purpose in Chongqing, China. The result showed that energy-saving rate was significantly associated with building type. Hospital building and hotel building made best use of reconstruction in four kinds of buildings, 43.92% and 34.5% respectively. That reflected how building running time and load rate effected on energy conservation in chilled water system, they determined the energy-saving potential directly. Further analysis revealed that energy-saving rate has negative correlations with air-conditioning area and annual water pump energy consumption. It was caused by pipe network resistance and the control strategy using fixed pressure differential set-point together. Besides, pump efficiency under part load, characteristic of pipeline network and other factors hard to quantify limited energy conservation too. Take a building in testing as example, in typical air-conditioning period, calculations show that energy-saving potential of chilled water system is 46.8%, the loss caused by control strategy using fixed pressure differential is 12.9%, the loss caused by pump efficiency is 5.8%, the loss caused by factors which are hard to quantify is 4.1%, actual energy-saving rate is 24%.

ABSTRACT. The indoor climate of libraries is expected to have critical negative impacts on the conservation of books and manuscript. Therefore, paper-based collections stored in libraries can possibly face to the chemical, mechanical and biological degradation phenomena if the indoor climate shows insufficient trend with respect to the instructions given in standards or norms. In this study, indoor microclimate of Necip Paşa Library, a historic building located in Tire-Izmir, Turkey, was investigated from the perspective of preventive conservation of manuscripts. The library, which was modeled with the help of building performance simulation tool, DesignBuilder, has no heating, cooling or ventilation system. The thermo-hygrometric parameters temperature and relative humidity) were monitored via data loggers throughout one year period and later used to calibrate the building energy performance model. The measurements showed high chemical degradation risk on manuscripts from April to November. In order to reduce the degradation risks on manuscripts, two measures were proposed: humidity control (humidification and dehumidification) and natural ventilation system. The model was simulated for each measure via building energy performance simulation tool. The results of humidity control system show that the new trend of indoor microclimate of the space in which manuscripts are stored cause less risk of chemical degradation.

ABSTRACT. The Finnish “Condition survey” concept is intended to give the owners and users of existing buildings, residential or non-residential, a reliable and solid basis for decision-making and planning for measures to improve the indoor environment or energy performance of the buildings, or both.

In this concept, the main focus is usually the performance of ventilation and/or air conditioning system, assessed primarily from the indoor environment point of view but taking into account also the energy performance aspects. So, the main principle is indeed to take into account both health and energy aspects. So, it is usually more extensive than the inspection required by the EPBD. The guidelines for condition survey were published first in 2013, after testing the approach in just a few buildings. In order to make the concept more common, altogether 18 pilot surveys were carried out and analyzed under supervision of the HVAC Association of Finland (SuLVI). The pilots included 12 non-residential and 6 residential buildings.

In non-residential buildings the survey is carried out in two phases: 1. Basic survey: study of documentation, walk-through, personnel interviews, general assessment of systems and maintenance, intermediate reporting including recommendations. 2. Detailed survey: detailed study of existing systems and equipment, including measurements, and final survey reporting including recommendations to owners and users.

In residential buildings, the two phases are combined into one survey. In the 18 pilot surveys, the guidelines were followed and assessed, using questionnaires prepared by SuLVI, both by the owners/ users and persons responsible of the surveys. SuLVI checked all survey reports, a few of which were also presented to representatives of all pilot surveys in a feedback seminar.

The pilot surveys can be regarded as successful, because they revealed many typical hidden problems in ventilation and air conditioning systems. These problems are seldom so serious that either the end users or maintenance personnel would have noticed any problems. For example, air flows into or from individual rooms can deviate 50% or even more from the planned air flows, pressure conditions indoors can stay inappropriate. These, and many minor faults in building automation and HVAC equipment can result in discomfort or unnecessarily high energy costs but can remain hidden without a systematic survey. Examples of survey findings will be discussed in the paper.

The pilot studies revealed that the main concept is applicable, but needs adjustments in details. There is also a need for training for persons who perform the surveys (typically HVAC engineers). Also a qualification scheme needs to be developed. It is essential that these experts have sufficient knowledge and understanding of the technical systems of buildings, including cooling and building automation. Even more training, and also practical tools, should be targeted to the clients - owners and users, among which very few decision-makers have any kind of technical education.

ABSTRACT. Building sector presents about 40 % of all primary energy use in European Union. Consequentially this sector presents a great potential of improving energy efficiency, enhanced usage of renewable energy sources and reducing emission of CO2. Beside other approaches for achieving these goals implementation of low-exergy systems for surface heating and cooling is very promising. The efficiency of those systems is mainly influenced by radiative and convective heat exchange on roof surface. Methods for calculating radiative fluxes on room surfaces are well developed meanwhile empirical models for calculating convective heat exchange on room surfaces are mainly obtained from experimental and numerical studies in empty rooms, which are rarely empty in practice. Those empirical equations mostly do not consider real boundary conditions in practice which can effect to over or underestimation of convective heat flux on thermo active room surfaces. We recognized lack of studies for mixed convection at real boundary conditions. Based on this recognition we provided a large experimental research program for mixed convection on vertical thermo active room wall in highly upgraded thermostatic chamber fully made in accordance with EN 442:1996. We experimentally analyzed effects to mixed convection of the most common situation in real rooms which disturb temperature and velocity field near the vertical thermo active room walls. We analyzed effects of vertical thermo active room wall width, flow obstacles alternately on the floor and below of the ceiling and the working place which at the same time presents the flow obstacle and the additional internal heat source in the room. Paper firstly presents theoretical background of the experimental study and main features and description of experimental setup. It continues with experimental results and further on it gives recommendations and limitations about using models for mixed convection on thermo active room wall in non-empty rooms.

ABSTRACT. INTRODUCTION: Europe is seeking new ways to meet the goals of the Kyoto protocol and it is accepted that in buildings there is a huge potential for reducing energy consumption. Insulating buildings is now an accepted measure and is relatively simple to achieve, commonly used and embedded in European and national legislation. However, an additional severe problem is rising: more and more energy is used for cooling of buildings. E.g. in the US there is already more electricity needed for cooling of buildings, than the whole continent of Africa uses electricity in total. METHODS: The big problem with regard to regulating temperatures in buildings becomes apparent in summer when unintentional internal and external heat loads cause rooms to get hotter by the hour. Here the building’s mass plays an important part in determining the resulting indoors temperature. Lightweight buildings do not possess enough mass to avoid heat build-up and can therefore overheat rapidly – even north of the Alps in Europe. Phase change materials (PCM) are a sustainable solution to this problem in that they offer a convenient means of adding thermal mass into lightweight buildings such that they behave more like a heavyweight structure. It will be explained how the principle works, how to calculate the effect by means of dynamic computer simulation and mobile tools, how cooling concepts can be optimized, and which product solutions are presently available. RESULTS AND DISCUSSION: The concept is demonstrated in a detailed case study of a passive house school in Diekirch in Luxembourg. The new building, which is based on steel frame construction, was monitored by Fraunhofer ISE / Freiburg and the results according to EN 15251 will be presented. CONCLUSIONS: The lightweight building has proven to fulfill the criteria of comfort class A. Not only in this case, phase change materials have proven their ability to enable better summer indoor comfort and cut down energy expenses when used in conjunction with A/C-systems. Therefore this means for better energy efficiency needs to be embedded in future EPBD calculation methodologies.

ABSTRACT. Advent of design and operation of high energy performance buildings in context of climate change, designers, and builder operators have focused on reduction of operational energy. Internal thermal mass plays crucial role in achieving thermal comfort especially in climates with large diurnal temperature range across day and seasons. Phase change materials (PCMs) are known for storing thermal energy by the virtue of their inherent latent enthalpies. Careful introduction of PCMs as internal thermal mass along with external insulation is likely to increase thermal comfort hours along reduction cooling energy in hot and dry climates. Form stabilized phase change materials promises to offer ease of construction without encroaching on valuable floor space occupied by building structure. This study evaluates influence of polymer fused PCMs on thermal performance of buildings. It deploys nontoxic, flexible material with high latent heat and structural strength above and below melting point. In first phase, study relied on whole building energy performance simulation to determine thermal characteristics of PCMs before its deployment in experimental setup. In second stage, an experiment was conducted in externally insulated rooms constructed in hot and dry climate. Ceiling tiles with PCM were installed in side by side constructed rooms measuring 3.0m x 3.0m x 3.0m. Fully instrumented rooms capable of measuring various indoor and outdoor environmental conditions and monitoring energy consumption provided insights into PCMs effectiveness. Study compares performance of mechanically operated air-conditioned room with a room having natural ventilation. Study quantifies cooling energy saving potential and potential increase in thermal comfort hours. Study also provide guidance to determine most appropriate melting point of PCM, which helps in manufacturing. A collaborative approach between R&D institute and PCM manufacture provide valuable results leading to understanding of PCM performance in Hot and Dry Climate.

ABSTRACT. In order to fit low energy building policies and reduce environmental impact of buildings, construction materials must have good balance between thermal properties and embodied energy. By using such materials, reduction of both operational and embodied energy are achieved simultaneously. Hemp concrete is a bio-based building material composed of the woody core of industrial hemp and lime based binder. It is a non-load-bearing material, which can be used as floor and around structural frames for walls and roof. The material is characterized by relatively low environmental impact, moderate thermal properties and, high air and moisture permeability. The properties vary with binder composition, mixing and casting techniques, as well as intended application. This research presents preliminary heat and moisture building simulations of single family house made out of hemp-lime composite. To evaluate the performance of hemp-lime, it is compared to models with common external walls, upon defined parameters. The article also determines the variation of thermal conductivity for hemp-lime commercial plaster and wall mix, as a function of moisture content. The most promising binder composition and mixing proportions for the wall mixture are identified through literature review; thereafter samples for the experiment are prepared and tested in laboratory environment. Thermal conductivity is found by using Hot Plate Apparatus λ-meter EP500, while moisture dependence is established upon testing samples with different moisture content. Results from the experiments show non-linear increase in thermal conductivity with increase in moisture content. The results and potential benefits of using hemp-lime are discussed and conclusions are drawn.

ABSTRACT. Large deviations observed between the actual and theoretical gas consumption in Dutch dwellings, cast a shadow of doubt on the accuracy of the energy labeling method. In this sense, the accuracy of the calculation methods as well as the inputs being fed, fall under the question. According to several studies, the significance of wall’s thermal resistance as one of the most sensitive inputs has become clear. From the lack of sufficient information regarding the exact construction of the existing walls, arises a necessity for in-situ measurements. However, such measurements are generally not being performed because the existing methods demand very long monitoring periods. In this research, a rapid transient in-situ thermal resistance measurement technique, Excitation Pulse Method (EPM), has been introduced, experimentally applied to a case study, and compared to the existing international standard method ISO 9869, showing a very good agreement. EPM is based on the theory of thermal response factors. It allows in-situ determination of the walls’ thermal resistance and the average volumetric heating capacity in a couple of hours. The method is therefore believed to aid in better and much quicker estimation of the thermal resistance Rc-value of the walls, leading to more accurate energy labels.

ABSTRACT. The nearly zero energy buildings (nZEB) ideology of the future obliges foremost that heat losses should be reduced remarkably compared to the present levels. The efficient way to meet these requirements is to design and build passive, highly insulated, nZEB buildings. The current study observes the hygrothermal performance of a single-family detached highly insulated house, built in Estonia. This paper presents a hygrothermal measurements data of the external wall with 3 different combinations of materials of this house, which has been in use for 2 years after construction. The analysis indicated that thermal resistance of the wind barrier layer and water vapour permeability of the vapour barrier had the strongest influence on the RH (and hence, to mould growth risk) in the critical point of timber frame exterior wall, which is between the insulation and the wind barrier surface. Field measurements have shown that typical household activities and performance of ventilation provide moisture excess ∆ν=4…5 g/m3 during winter period. This indicates that in design of highly insulated houses indoor humidity loads cannot be decreased. Therefore, the building envelope of the highly insulated building needs careful hygrothermal design and thorough consideration of different material properties.

ABSTRACT. It is known that the EPBD recast has introduced the near-zero energy building. Following Annex III of the 2010/31/EU Directive, the Guidelines have been issued. In these guidelines energy efficiency measures have been identified and evaluated both from the energy and economic points of view.

The definition of energy efficiency measures and packages are strictly related to the climate, considering both temperature and humidity. Therefore, for hot and dry regions specific solutions are certainly required. In particular, Mediterranean climate is characterized by a dominant cooling demand that requires an analysis of the dynamic behaviour of the building systems.

Behaviour of outer walls play an important role on heat gains and heat losses of the building. Thermal insulation of walls is known as an important measure to reduce static heat loss of buildings for cold and mild climates. However increasing thermal insulation thickness plays a reverse effect in dynamically changing hot climates. Evaporative cooling of outer walls can be a very valuable tool reducing cooling loads from outer skin of the buildings in such climates.

An evaporative layer to be applied on the inner surfaces of outer walls has been designed and proposed in this study for Mediterranean region. Considered building has an air conditioning system that keeps indoor temperatures at the required level. The target is reducing cooling loads for energy conservation. The proposed layer basically consists of two plate with a gap between them. Indoor air passes through in this gap from bottom to top all the length of the wall. Inner plate is actually a moist pad and evaporation of water from this pad creates a cooled surface. Proposed system to be coupled with the present ventilation system of the building. Present ventilation system can be either natural or mechanical. Exhausting indoor air passes through the proposed evaporative layer, receives vapour and then this moist air is exhausted to the atmosphere by help of an exhaust fan. Cooling of inner surfaces of the outer walls reduces heat gain and increases the thermal comfort.

A case study has been conducted to analyse the effectiveness of this proposed system. A sample building in İzmir has been considered and this proposed system has been designed and applied to this building. A simple program has been developed to design the system. Performance of the system has been investigated by the help of a building simulation software. It has been shown that this system is more successful comparing the thermal insulation in Mediterranean climate. Depending on the design parameters more than eighty percent of the peak heat gain through the outer walls can be compensate by the system without any additional insulation layer. In some configurations even a reversed heat transfer (heat loss from indoor) can be achieved. This layer is also effective during the winter conditions. In winter the layer is used in dry state and it reduces the heat loses by increasing the inner wall temperatures. A feasibility study has also been carried out and simple payback times have been calculated in this study.

ABSTRACT. Topic proposal: From sustainable buildings to sustainable cities

Green façades are not just a novel and decorative cladding for contemporary architecture, but are also the focus of much research in building physics. Besides the role of green façade in the thermal protection of buildings, principally in the reduction of cooling energy demands, their benefits on the psychical quality of the sustainable urban environment are also significant. In recent research, green façades are modelled with the parameters of green roof. The performance of the two structures are principally different therefore a detailed examination of the thermal properties of green façade is required. The aim of this research is to develop a method, which can simplify the establishment of thermal transmittance of green façades. The examined green façade cladding system consists of different layers, including stainless steel boxes, which contain substrate, and a front plate behind the plant coverage made of painted mineral wool. The water content of the substrate and the plants make the complexity of the structure even higher as they do not have a permanent condition. The calculation of the unit heat loss rate of a green façade with ordinary methods is not possible. Therefore an experimental measurement system was needed to be installed on a green façade in Hungary. Examination of the external surfaces and air temperature was carried out on several points of the façade. Based on the measured data, thermal transmittance can be calculated. This research studies the factors that may affect the accuracy of this method: the accuracy of the measurement system, the temperature difference between the two sides of the structure, the places where sensors are installed, the frequency and length of measurements and the different methods calculating a mean value. This paper represents the effects of these factors and the sensibility of the calculation method on the different factors. Based on these calculations, the measurement of the thermal transmittance of a modular green façade cladding system may be simplified and shortened without decreasing the accuracy.

ABSTRACT. One of the European Directive priority are represented by the improvement of “building performance requirements” and the development of new strategies for “very low energy buildings”. The goals, in particular, is the reduction of the energy consumptions due to the heat flux transmitted through the envelope of residential and commercial buildings. In regions, like Mediterranean region object of this study, with high level of solar radiation ventilation allows to the cooling load during summer period and contributes to the reduction of the energy needs of buildings. The most important advantages is the reduction of the heat fluxes transmitted by the structures exposed to the solar radiation, thanks to the combined effect of the surfaces shading and of the heat removed by the air flow rate within the ventilated air gap. This paper illustrates a numerical investigation on a prototypal ventilated roof for residential use. Due to geometric and thermal symmetry the system has been studied considering a single side of the pitched roof. The roof is long 6.0 m, inclined from the horizon of 30° and the ventilated channel, under the roof, has a height of 10 cm. The analysis is carried out on a two-dimensional model in air flow and the governing equations are given in terms of k-ε turbulence model. The investigation is performed in order to evaluate thermofluidodynamic behaviors of the ventilated roof as a function of the following geometric parameters: 1) channel gap or height equal to 5, 10 and 20 cm; 2) Inclination of 15°, 30° and 45°; 3) Hight of the ridge of 5, 10 and 15 cm. The problem is solved by means of the commercial code Ansys-Fluent and the results are performed for an uniform wall heat flux on the top wall equal to 800 W/m2. Moreover, some different solutions of the exit section have been investigated. Results are given in terms of wall temperature distributions, air velocity, temperature profiles in different cross section of the roof in order to estimate the differences between the various configurations. Further, the ventilated roof has been compared with other types of roof.

ABSTRACT. INTRODUCTION: The roof, as part of the building envelope, is one of the most important areas in the development of sustainable buildings. Various roof design strategies have been developed for reducing building energy usage, generating energy, improving water retention, and waterproofing. Due to an increasing interest to maximize the utilization of building spaces, including roof area, these strategies are actively utilized. However, there are some challenges on finding integral optimal solutions among sustainability, funding, and environmental recognition. Although sustainable roof design technologies have been utilized and improved in prior roof design efforts, they are mostly focused on a single technology, such as either green roof, cool roof, or solar energy generation by PV panel installations. It is quite obvious that if more than one sustainable roof design strategy can be applied, more valuable effects can be achieved. This requires creating a quantitative analysis between spectrums of roof performance factors. Integrating different roof functions such as green roofs, cool roofs, and PV systems is of building practitioners’ interests in order to meet certain criteria in terms of energy efficiency, cost effectiveness, and environmental impact. The key question which should be considered is what are the best and/or optimal strategies of utilizing roof areas in commercial buildings to achieve sustainability goals such as NZEBs or Carbon-Neutral buildings? The main aim of this research is to develop a framework which offers the optimal combination of different roof functions in order to maximize cost savings associated with energy performance and roof functions installation and maintenance costs regarding environmental impact as a constraint. METHODS: This research presents an enhanced roof system or framework that includes a mathematical optimization model as a core that is fed primarily by energy, cost and environmental analyses. It integrates multiple roof functions and optimizes desired roof performances. Energy analysis, which was carried out through roof energy simulation, plays a major role in this framework. The framework or mathematical optimization models has been tested using a case study building on Duke University campus. The test results are discussed in terms of energy efficiency, cost savings, and environmental impact. RESULTS/ DISCUSSION: Through this innovative approach, the inclusion of energy use mitigation and environmental benefits for different roof functions can reduce the investment gap between different roof types which mainly depends on the climate and roof type components. CONCLUSIONS: This proposal presents a novel approach to select a set of different roof types to achieve certain objectives. In this analysis, maximizing the energy savings has been considered for the optimization. Appropriate constraints are developed to account for the dynamics of the system in terms of roof coverage and etc. Environmental effects of different roof types are also considered in the proposed research. The emerged results are investigated and several sensitivity analyses are performed.

ABSTRACT. The paper will report on an extended analysis of an EU research project with the aim of investigating children’s exposure to indoor air pollutants and health risks in European schools. The EU project involved 38 partners from 25 countries. Overall, 114 schools were selected from the 23 countries for the field activities, which cover a total of 6174 children in 54 schools and 148 classrooms. To further assess the impact of the indoor environment of school classrooms and its effect on student learning, about 46% of all the school children performed an attention/concentration test which included a simple mathematical tests and a logical test. Previous studies on learning capability and indoor climate parameters, such as daylight, usually refer to studies conducted in USA. This paper will show the impact of daylight in the indoor environment of school classrooms and its effect on student learning. The analysis show a positive relationship between light-related variables and performance, and the most import determinant is the window to floor area.

ABSTRACT. INTRODUCTION Indoor climate comfort is important task for historical building preservations. A case study focused on the thermal and daylight condition in a building that is historically protected premise – the UNESCO protected villa Tugendhat located in city of Brno in the Czech Republic.

METHOD Indoor climate conditions were studied in the building. Computer simulations were carried out for the thermal and daylight climate in the main residential area of the building. Temperature distribution and ventilation system as well as the building insolation study for direct sunlight and daylight conditions for overcast sky were simulated.

RESULTS The simulations give results about the indoor climate quality in the residential area of the villa designed and constructed in the unique architectural concept.

ABSTRACT. Buildings consume about 40% of the annual world energy consumption and 70% of the annual generated energy in some hot climate countries such as the State of Kuwait. Residential sector has the major share of the energy consumption among other building sectors. This share will be significantly increased because of the planned residential cities. More than 30% of the buildings consumption can be saved if the building design is optimized. Building performance is directly affected by many design parameters such as building orientation; envelope layout; construction materials; heating, ventilation, and air-conditioning (HVAC) system; and lighting system. Each of these components involves many parameters and considering all these building parameters together complicates the problem, increase computation time and may not provide the best solution. Therefore, dividing the complicated building problem into similar and interrelated simpler problems improves the solution and results analysis. Among the divided building problems, the window system represents a real challenge in hot climate countries. Such type of problem needs to link a building simulation program such as EnergyPlus with an evolutionary optimization algorithm, in this research, Genetic Algorithm (GA). Coupling EnergyPlus with GA enables the achievement of practical and reliable window solutions. These solutions provide reliable data for building design to comply with building standards requirements particularly those for energy efficient buildings. The results also provide practitioners and architecture firms with the necessary data of windows layout and construction guidelines. For this reason, the main aim of this paper is to minimize the heat gain through a residential house window and maximize the daylighting through it. The designs variables relate to these objectives are window-to-wall-ratio (WWR), window glazing layers, frame and divider, and shading devices. The solutions are provided for different orientations, zone activities, and layout design. The preliminary results showed that WWRs from about 17% to 70% with different shading devices were obtained. This work can be extended for different building aspects such as construction materials and mechanical and electrical systems.

ABSTRACT. Introduction

The total life cycle energy consumption of a building overall consists of two components: embodied energy and operational energy. Minimising the embodied energy in building components is a neglected task in building design as focus tends to be on the operational energy and operation of buildings. The question is, however, whether results from rather time-consuming analysis of embodied energy provide information that will influence the ranking of building components in terms of their total life cycle energy consumption. This paper features an analysis of how to rank four different low-energy windows for a retrofit scenario based on their energy-efficiency. Initially, the windows are ranked according to the output from two different methodologies for calculation of operational energy performance. Later, it is investigated whether embodied energy has any influence on the ranking of the windows.

Methods

It is assumed that the existing windows in a dwelling have no remaining lifetime and is to be replaced. Four low-energy windows are therefore ranked according to their operational energy consumption to select the most energy-efficient solution. The operational energy is calculated in two different ways to investigate the impact of calculation method on the ranking of the windows: 1) a simple energy balance methodology called Eref, which is used for energy labelling of windows in Denmark, and 2) a dynamic building energy simulation of the four windows with offset in a specific retrofit case. The embodied energy in the windows is then calculated and added to the operational energy consumption calculated in the dynamic simulations to investigate whether inclusion of the embodied energy in a life cycle assessment (LCA) rearranges the ranking of the windows.

Results and Discussion

The result of the Eref-calculations is an unambiguous ranking of the windows with a clear “winner”. One of the windows has an Eref-value below the minimum requirement in the Danish Building Regulations 2015 (BR15) and is thus disqualified for both new buildings and retrofitting projects. Interestingly, the dynamic building simulations show another ranking where the Eref-ranking is more or less turned upside down. Taking the embodied energy into consideration in an LCA does not alter the result of the dynamic simulation ranking.

Conclusions

The analysis presented in this paper indicates that it is critical to not select windows for building retrofit according to an Eref ranking of the energy-efficiency. Instead, the appropriate choice of windows must rely on an analysis of the specific building retrofit case. Taking the embodied energy into consideration in a total life cycle energy consumption analysis does not influence the ranking of the windows as the amount of embodied energy in the windows only makes up a negligible part of the total life cycle energy consumption.

ABSTRACT. Water flow window is a multi-glazing system with a flowing water layer in the window cavity. In its buoyant-flow design, the water flows in a closed loop between the window cavity and a double-pipe heat exchanger above the glass panes. Thermal energy carried away by the warm water stream in the cavity was released to the cold feed water in the heat exchanger for supporting the domestic hot water system. Because of the thermal extraction, the room cooling load, particularly for cooling-dominated climate, is reduced. Thus both the energy consumptions of the domestic hot water and the room air-conditioning systems are reduced. In the original conceptual design, two headers with evenly distributed openings are located at the top and bottom ends of the window cavity. This is to provide flow uniformity across the window width during the solar heat absorption process. In the modified experimental prototype design, these two headers were removed, and the system performance was evaluated firstly via experimental measurements, and then via computer modeling and simulation. Validation tests were carried out to prove the correctness of the FORTRAN program used to predict the performance of the window system. Afterwards, the numerical model was applied to evaluate the typical summer and winter performance based on the typical weather conditions of Hong Kong, a subtropical Asian city. The findings indicate that the heat transfer between the glazing surfaces and the liquid water layer were enhanced; the surface temperature of the inner glass pane was observed more uniform then the previous case with the presence of upper and lower distributors. The mass flow rate of the circulating water stream is also found affected by the return water pipe diameter, but yet the overall system thermal performance is hardly affected.

ABSTRACT. Generally, in a room with thermally active building systems (TABS), there is a removal of thermal load through an effective heating or cooling surface to maintain a set-point temperature of the room, and therefore the characteristics of radiant temperature distribution of the room have been changed according to the interior load fluctuation. Thus, because it can cause discomfort when there is a radiant asymmetry between surfaces, it is necessary to consider characteristics of heat transfer on the surface of the ceiling related to the operative temperature as the reference temperature during the design process. The radiant and convective heat transfer between ceiling and the others is commonly influenced by several parameters, such as the shape of the surroundings, interior air stratification and air velocity. Because convective and radiant heat transfer coefficients between a heating/cooling surface and the room have different physical behaviors and are calculated with different reference temperatures, it is very important to determine an appropriate reference temperature when calculating the total heat transfer coefficient. Furthermore, the operative temperature can also be the reference temperature when considering the thermal comfort condition. Additionally, for the thermal output calculation of TABS during the design process, the surface heat transfer characteristics should be considered according to the room conditions. This study aims to analyze the characteristics of convective and radiative heat transfer in the ceiling of TABS, which can affect the operative temperature related to occupants’ thermal comfort. For this purpose, we have reviewed the basic equations of convective and radiant heat transfer coefficients, for which the reference temperatures are the air temperature and the average unheated surface temperature (AUST), respectively. We have also conducted a theoretical study regarding the reference temperature and, finally, evaluated via simulation according to the variables related to the coefficients and equation.

ABSTRACT. The pedestrian-level wind environment quality in the street canyon formed by high-rise buildings and other low-level buildings will be affected by multiple factors such as, the height and geometry of surrounding buildings, the width of street, wind direction, and wind speed. This study adopted wind tunnel experiments to observe the characteristics of the pedestrian-level wind environment in street canyons under different conditions including different street widths, heights of high-rise building (also the height of the podium), and incoming wind directions.

The experimental results revealed that the effects of street canyon width on the pedestrian-level wind field in a street canyon can be summed up into 3 types of flow patterns. Podium height dominated the wind field characteristics of the street canyon. Regardless of how large the street canyon width is, its inside all had dimensionless average wind velocity higher than the wind velocity before entering the street canyon, and there were significant channeling effects; while the wind fields inside the street canyon were greatly affected by the podium height. For higher podiums, the wind field velocity inside the street canyon was greater.

ABSTRACT. Due to an increased insulation rate and more energy efficient ventilation systems, the production of domestic hot water (DHW) is growing in importance in the overall heat demand of residential buildings. The selection of a DHW-system with a high production efficiency is therefore important to reduce primary energy use in buildings. Besides selection also a proper use, including adequate sizing and control strategy, will have a positive effect on overall production efficiency. In a recently executed research project, funded by the Flanders government (IWT), the selection and sizing instructions for domestic hot water installations are being revised. Hereby, a large attention is paid to the actual hot water demand or DHW tap patterns. These tap patterns are gathered by a large number of detailed measurements and simulations. To deal with this enormous set of data, a methodology to characterize tap patterns is needed to generalize the results which are achieved in this project. Clearly, this characterization depends on the purpose for which it will be used. First, a methodology to size production units based on tap patterns is presented and illustrated with a number of measurements and elaborated case studies. The basic idea behind this methodology is that the tap pattern will be characterized by the maximum demand within a time step and this for different step sizes. This approach allows to present an overview of possible topologies, which will all meet the net heat demand of the selected case study an any time. Afterwards to present some guidelines towards selection, the influence of tap patterns on different topologies is discussed. This discussion is funded with some lab tests executed according to the recently induced Ecodesign regulations. As a result of these considerations, some guidelines to optimize sensor positioning within storage tanks are presented and an evaluation is made regarding the applicability of the Ecodesign labeling within energy performance calculations for buildings.

ABSTRACT. Introduction Due to the increasing building standard in the last years the specific heat energy demand for new buildings but also for refurbished buildings decreases. Due to this fact the percentage of end energy use for hot water production rises. But small scale devices, which can be used for decentralized applications, are hardly available. Usually devices with a high nominal power, short operation times and small capacity utilization are used. Therefore there is a lack on devices for heating and cooling for small scale applications (<2 kWthermal), which do not have moving parts and therefore need low-maintenance, which have no noise emissions and therefore can be used for decentralized applications and which do not use climate-relevant refrigerants.

Method The focus of this paper is the decentralized production of hot and cold water with Peltier elements. Therefore two prototypes with a hot and cold water storage were measured. Between the hot and cold water storage Peltier elements were placed. The temperatures (surface temperatures and water temperatures inside of the hot and cold storage) were measured with calibrated PT100 temperature sensors. The electrical power consumption of the Peltier elements was measured with a calibrated power analyzer. Different voltages were applied to the Peltier elements and the coefficient of performance (COP) as the heating power related to the electrical power consumption was evaluated in each case.

Results The measurements showed, that the best COPs could be reached when the Peltier elements were operated in the part load range, which was 5 Volts this case (the maximum applicable voltage was 29,5 V according to the manufacturer). The maximum COP as a mean value over the first hour was reached with 5 Volts with an initial temperature of both storage tanks of 15 °C. This COP was 1.6. The temperature at the highest measurement point of the hot storage water tank was 17 °C. Compared with a high voltage application of 15 V the mean COP for one hour was 1.0 with a hot water temperature of 24 °C.

Discussion The measurements with two different prototypes showed interesting results. However, it has to be stated that these results were achieved without forced convection of the cold and hot side of the Peltier elements. Therefore it can be assumed, that better results will be possible, if a forced convection on the cold and hot side will be applied. The forced convection will enable lower temperature differences on the Peltier elements and therefore will reduce the losses due to higher temperature differences.

Conclusion The use of Peltier elements for the production of hot and cold water showed, that a maximum COP of 1.6 could be reached only by natural convection on the hot and cold sides of the Peltier elements. The results are interesting for future research in the building sector. In multi storey buildings e.g. the hot water production could be covered by such a decentralized system with a hot and cold water storage.

ABSTRACT. This article studies some of the statistical properties of domestic hot water (DHW) consumption. The study is based on experimental data obtained for a group of households, over a 1 year period. To describe the consumptions, we consider three representative statistical properties of the drain sequence associated to each household: i) the distribution of the magnitude of the drains, ii) a daily pattern of the start times of consumptions, iii) the time between two successive drains. A remarkable outcome of the study is that the time between two successive drains follows a bimodal Weibull distribution. This opens perspectives for piloting applications.

ABSTRACT. The hourly profile of domestic hot water (DHW) is required for system sizing and energy simulations. This paper addresses the hourly DHW profiles for Finnish apartment buildings. The hourly consumption of 191 occupant during one year data were processed. Hourly profile for August, November and January had similar consumption pattern and monthly variation of consumption were also illustrated. Higher variation of consumption was noticed during peak hours and 90% of consumption variation were in between the range of 0-20 L/per./hour. The average consumption during peak and non-peak hours were 3.6 and 1.5 L/per./hour respectively. To understand the effect of the number of occupants on hourly peaks five profiles were drawn for one person, 3 people, 10 people, 31 people and 191 people group. All profiles followed similar DHW consumption pattern and a specific selection procedure was applied for a number of good candidates in order to select the most representative real consumption data based profile for each group. The results revealed higher evening peaks compare to morning peak and smaller groups had a higher peak consumption values compared to large groups. The obtained profiles accompanied by scaling factor can be used with monthly consumption factor of DHW to deliver the hourly profile for any month. Average DHW ratio was 0.31 and varied from 0.10 to 0.39, but was not sensitive to hourly consumption.

ABSTRACT. The Rosborg Gymnasium building in Vejle (Denmark) is partially founded on 200 foundation pile heat exchangers (energy piles). The thermo-active foundation has supplemented the heating and free cooling needs of the building since 2011 (4,000 m2 living area). Operational data from the ground source heat pump installation has been compiled since the beginning of 2015. The heating requirement of the building supplied by the ground source heat pump exceeds the free cooling covered by ground heat exchange. The asymmetric utilisation of the soil should in principle, imply a decrease in the long-term ground temperatures. However, operational data show that the temperatures of the heat-carrier fluid do not fall below +4.2oC during the heating season (winter) and that the soil recovers to undisturbed conditions during the summer when heat demand is low. In addressing the consequences of an imbalanced ground heat extraction/injection activity, this paper provides a performance study of the energy pile-based ground source heat pump installation utilising operational data. The study demonstrates that the measured seasonal performance factors so far are lower than expected: 2.7 in heating mode and 4.2 in cooling mode. Nevertheless, there is room for improvement if novel energy management strategies are applied. This highlights the relevance of considering the daily heating/cooling requirements of the building during the design phase of the heating and cooling system. Moreover, this study demonstrates the feasibility of ground source heat pump systems based on energy foundations in heating-dominant buildings.

ABSTRACT. The effective ground thermal conductivity and borehole thermal resistance, which are key parameters in the design of borehole heat exchangers (BHEs), are often determined using an in-situ thermal response test (TRT). The results of TRTs in saturated porous formations have been reported to depend on the heat injection rate. If this dependence is examined using multiple thermal response tests at a single heat injection rate, the ground takes a long time to return to the initial temperature between tests and the ground conditions have changed. Therefore, the results of multiple TRTs will not depend solely on the heat injection rate, and many uncertainties can be included. In this work, a new practical method is proposed to minimize the effect of temporal changes in the ground condition. The method combines a multi-heat injection rate TRT with a parameter estimation method using the infinite line source model and the quasi-Newton method. TRTs were conducted with two different borehole heat exchangers installed in a saturated sandy formation to verify the effectiveness of the proposed method. The proposed estimation and experimental methods are relatively simple; however, the magnitude of the natural convection can be determined without detailed analysis of the subsurface condition.

ABSTRACT. INTRODUCTION Ground source heat pump systems are energy-efficient and environmentally-friendly means of providing building heating and cooling. Design of the ground heat exchangers for these systems can be challenging for several reasons including estimation of the borehole thermal resistance. The borehole thermal resistance – that is, the thermal resistance between the fluid in the U-tube and the borehole wall – is a key performance characteristic of a closed-loop borehole ground heat exchanger. Lower borehole thermal resistance leads to better system performance. Since the original identification of the concept of borehole thermal resistance by Mogensen (1983), there have been numerous methods proposed for calculating this in the case of grouted boreholes. Either a single or double U-tube heat exchanger involves multiple eccentrically placed cylinders within another cylinder and therefore leads to difficulties in analyzing the conduction heat transfer problem. Therefore, a number of simplified methods, which are usually accurate only over a narrow range of geometries, have been developed. The multipole method developed by Claesson and Bennet (1987) is accurate over a wide range of geometries, but is mathematically challenging to implement. For ground-water filled boreholes, several authors have shown that the borehole thermal resistance can vary with both heat transfer rate and annulus temperature due to variations in the buoyancy-driven flow and heat transfer. However, no convection correlations have been available until recently and therefore designers have had to rely on thermal response tests for similar boreholes. When a thermal response test is used to measure borehole thermal resistance it inherently includes the effects of internal heat transfer between tubes in the ground heat exchanger, and is referred to as the effective borehole thermal resistance. Hellström (1991) developed analytical relationships between the local borehole thermal resistance and the effective borehole thermal resistance. METHODS An Excel/VBA spreadsheet was developed that contains an implementation of the multipole algorithm and can calculate resistance using any order multipole for grouted boreholes. For groundwater-filled boreholes, we utilize a recently published correlation (Spitler, et al. 2016) for the natural convection in the borehole annulus. The effective borehole thermal resistance can be determined using either of Hellström’s formulations. RESULTS AND DISCUSSION Sample results and validation against experimental measurements from several boreholes are presented. The effect of thermal short-circuiting is proportional to the ratio of the tube-to-tube conductance to the thermal capacitance of the working fluid and is more important as borehole depth significantly exceeds 100 m. CONCLUSIONS This paper presents a new tool for calculation of borehole thermal resistance for both grouted and groundwater-filled borehole ground heat exchangers. It avoids the use of simplified models for grout resistance and is the first tool to be able to calculate borehole thermal resistance for groundwater-filled boreholes based on an experimentally-determined convection correlation.

ABSTRACT. Available throughout the world and used in construction for thousand years, earthen materials are well known for their significant properties. The later relies on their abilities to buffer moisture and improve indoor air quality while keeping the internal temperature relatively stable. In Rhône-Alpes, France, the rammed earth technic is the most spread and consists in compacting layers of earth, one by one, within a framework.

Current thermal standards, which are mainly based on static performance of the material (and in particular, on its thermal resistance), urge to insulate walls. However, like others hygrothermal materials, the thermal behavior of rammed earth is significantly above the expectations. It can be attributed to its interaction with its environment, catching and releasing heat and moisture.

The objective of the paper is to highlight the living comfort provided by non-insulated rammed earth walls, for different orientation, from in-situ measurements over more than two years. Winter, with no or a low energy consumption for heating, and summer, with no cooling device, are studied. The study points out the important role of solar irradiance on the thermal balance of the house, and thus the importance of a good architecture. More precisely, the paper deals with a quantification of thermal lag and temperature buffering induced by rammed earth, their link with usual parameters such as effusivity and diffusivity, as well as a comparison with other construction materials.

ABSTRACT. n order to improve the efficiency of the ground source heat pump systems, the effect on the performance of various borehole heat exchangers (BHEs) should be investigated carefully. This paper aims to study the thermal performance of coaxial borehole heat exchangers (CBHEs). A three dimensional model was established based on the commercial computational fluid dynamics software FLUENT to simulate the performance of CBHE. The heat exchange rates were analyzed and compared with that of a single U tube BHE. The soil temperature distribution around the CBHE and single U BHE is presented. The Effects of pipe material, flow direction and flow rate on the thermal performance of CBHE are discussed. The simulation results show that these factors have different degree of influence on the system performance.

ABSTRACT. INTRODUCTION. The development of a lively market of energy efficiency investments on the existing building stock asks for the engagement of building owners and managers. Such a commitment, in turn, rests with a clear understanding of the improvements that energy efficiency upgrades may bring to properties financial performances. Academic literature suggests a positive relationship between environmental and financial performance in property investments: in addition to the energy savings related to the building renovation, co-benefits can be reaped, ranging from being healthier to providing lower ownership risk. Examples of studies addressing the link between green investments and quantification of intangible returns come from the hotel sector. In hotel businesses, the impact of benefits on the hoteliers’ finances comes from workers and guests’ satisfaction and from the building performances, tackling all at once comfort, health, market appreciation and residual value. In this context, the paper describes the EU prescribed cost-optimality calculation performed for a hotel building and proposes an experimental revised version on the cost-optimal methodology, in which the co-benefits of energy retrofit are assessed and included in the calculation. METHODS. An Italian existing Reference Hotel (RH) was selected as baseline model for the cost-optimal analysis. A number of Energy Efficiency Measures (EEMs) for the building envelope were applied to the RH, in compliance with the Italian new mandatory and nZEB levels of performances. Combinations of EEMs composed 10 packages of measures, for which energy performances were assessed through a dynamic energy simulation software. Firstly, primary energy consumptions and global costs of the packages of EEMs were derived to identify the cost-optimal configuration from a financial point of view. The second step of the work dealt with the definition of a revised version of the formula for global cost. Extra costs and gains related to the green value of the retrofitted building were listed and quantified based on literature assumptions. The proposed “global cost-benefit” formula was then applied to the 10 packages of EEMs. RESULTS AND DISCUSSION. The cost-optimal level of energy performances reachable through the implementation of specific configurations of energy efficiency measures for the building envelope in a Reference Hotel is the first outcome of the research. Results from the second part of the research show the gap between the global cost and the proposed global cost-benefit for each package of EEMs. The contribution of the latter in modifying the previously defined cost-optimal level of energy performance is presented and discussed. CONCLUSION. In order to boost the market investments in energy efficiency, key actors should be informed about the improved financial performances of deeply retrofitted buildings, in terms of direct avoided cost and indirect co-benefits. Based on literature assumptions and estimations, the present work strives to quantify the potential positive effect of such co-benefits in the definition of the cost-optimal level of energy performance of a reference hotel.

ABSTRACT. The building sector must reduce its energy consumption and integrate more renewable energy sources in its supply systems if countries are to achieve energy security and manage climate change. Several technological/constructive options are available to improve building’s energy efficiency. However, building owners do often remain unmotivated, are overwhelmed by different technologies and do not know the best investment strategy for a limit budget. From the work done so far, we identified a lack of a dynamic system evaluation with simplified models as a reasonable compromise between system resolution and computational effort. The approach presented in this paper aims at a combinatorial optimization approach for retrofit measures concerning the building envelope and the heating system under consideration of dynamic effects and different target figures. To identify the most appropriate retrofitting options for single and two family house owners we propose a Pareto optimisation using genetic algorithm. We use a dynamic calculation of the thermal building and system engineering behaviour programmed in Python. The building is modelled with a low-order model. For the system engineering we use a new approach based on dynamic plant expenditure figures. As a decision support tool the model approach only needs easy accessible system data from the user. The results are assigned to different personal needs but also to appropriate collateral requirements relative to regional or national goals in energy savings.

ABSTRACT. Introduction “Total Concept” is a European project under the IEE programme (Intelligent Energy – Europe). The project responds both to EU objectives to support the major refurbishment of existing buildings towards Nearly Zero Energy Buildings and to national goals on reduced energy use in existing buildings.

Method The Total Concept method is a systematic approach that focuses on reducing energy use in existing non-residential buildings within the profitability frames set by a building owner, who plans to invest in renovation measures. The method differs from other approaches by making use of a comprehensive energy audit plan, advanced energy simulation methods, a complex economic model and analysis of measures that may have a reasonable energy-saving potential. The work process of the method includes clearly defined tasks, roles and responsibilities for the different key actors commonly involved.

Results and discussion This paper presents results from recently analysed data on two Danish buildings being renovated according to the procedure of the “Total Concept” method. The method leads to the identification of a package of energy saving measures, which as a whole fulfils the property owner’s profitability requirements. After implementation of the action package, it is planned to follow- up on the energy use and validate profitability of the action package.

Conclusions The results from the demonstration buildings in Denmark show that with the Total Concept method, it may be possible to obtain a profitable energy reduction up to 40%. The Total Concept method provides therefore an opportunity to access an essential part of the great energy savings potential in existing buildings by carrying out energy saving measures in a commercially profitable way - as one package of measures that fulfils the profitability requirement of the investor.

ABSTRACT. Compared to their European counterparts, Australian governments have invested relatively little in recent times in the energy efficiency upgrading/retrofitting of existing homes. This paper describes the development and implementation of a comprehensive methodology to optimise the delivery of energy efficiency upgrades to the homes of low-income, older (>60 years) Australians. The research presented was conducted as part of an AUS$5M project entitled, ‘Energy Efficiency in the 3rd Age (EE3A)”, which targeted low-income older residents in the Illawarra Region of NSW, Australia, and was funded under the Australian Federal Government ‘Low Income Energy Efficiency Program (LIEEP)’. The present project comprised both a social marketing and behaviour change component with ~650 households, and a retrofit program for a subset of ~200 of these homes. Households included those from both the general community (home owners) and from the aged-care sector, i.e. those living in Independent Living Units (ILUs). Between approximately $750 to $5,000 was spent on each home for retrofitting elements ranging from installation of roof and underfloor insulation, through solar hot water and reverse-cycle air conditioning systems, to draught-stripping and energy consumption displays.

The paper describes the development of a unique Building Characterisation Tool, which was implemented on laptops/tablets and facilitated the rapid recording of up to 2,000 features of each building, and also included information on the ways in which the occupants used the building. Following the auditing of the 200 homes, a retrofit optimisation process was developed whereby a detailed assessment of each home was made from the Building Characterisation data, and a set of retrofits prioritised from a short-list of possible options. The final installation of the retrofits was then carried out following a rigorous budgeting and prioritization process and then face-to-face consultations with each household and the signing of legal agreements.

Results are presented on the building characteristics of the dwellings occupied by this vulnerable section of the population. The general building typologies and detailed information on the characteristics of the homes and the resultant retrofit prioritisations are discussed. Commentary is provided on the challenges that arise when assisting this older, low-income household demographic, particularly with respect to government-funded household upgrades, and measures developed in the present project to overcome these challenges.

ABSTRACT. In France, almost 75% of the existing buildings will always persist in 2050. In fact, the thermal refurbishment rate of the existing residential buildings which present a high potential in energy saving, is estimated less than 1% per year. In the aim of accelerating this renovation rate till 3% per year, seeking optimal technical solutions taking into account the economic, environmental and societal criteria is a very complex problem due to the high number of parameters to consider. The main objective of the present work is to propose a fast method to find the global optimum. This method is based on the development of polynomial models for the prediction of heating energy needs, final energy needs and thermal comfort. To establish these models, we used the design of experiments method and dynamic thermal simulations using TRNSYS software. From these models, a sensitivity analysis has been achieved in order to identify the leading parameters on energy requirements. A database associating each parameter for its cost and environmental impact on its lifetime was generated from CYPE software and INIES database. Then, a detailed parametric study was performed using polynomial functions for determining a set of optimal solutions using the Pareto front approach. We implemented our method to a project of energy rehabilitation of an existing building located in La Rochelle (France). The developed multicriteria decision method showed a great potential for existing buildings rehabilitated with high energy efficiency. It allows a very fast operational optimization of sustainable buildings at reasonable cost and low energy consumption.

ABSTRACT. Introduction In the EPBD directive, the EU has set nZEB requirements to new buildings (2020) and all existing buildings (2050), which applies also to hospitals. Hereby, it is essential to guarantee optimal and sometimes live saving functionality while saving energy. Therefore, achieving these requirements in hospitals is a greater challenge than, for example in offices. Hospitals have the highest primary energy consumption of all in the Built Environment. Previous studies show that circa 70% of the energy use by Academic Hospitals (AMCs) is related to building and building services to realize the required indoor conditions. Research has shown several lacks in: Monitoring Activity, Building Energy Performance and match between: Building–User–Services. This study was aimed to verify the existence of the aforementioned lacks and to indicate the potential of energy savings that can be achieved.

Method The project objectives were obtained through a three-step methodology: in-depth analysis of case-study, development of an design approach and energy calculations. The in-depth analysis of the case AMC includes literature study on specific requirements for indoor environment and energy consumption in Hospitals, several interviews with the technical staff and building visits. The approach and energy calculations were performed on the outpatient departments of the Policlinic building. The existing Policlinic (built in 1986, G.F.A. ≈ 70,000 m2) was chosen as an interesting case-study. The building is extensively used and although its lifetime has been extended (from 10 to 30 years) any thorough re-commissioning has not been performed and maintenance is provided on a minimal level. These circumstances occur in many AMCs and their campuses, which are in continuous transition to upgrade primary processes according to the latest insights and developments.

Results and discussion The in-depth analysis has provided a clear picture on how buildings (in this AMC) are currently managed. The results show that little attention is directed on inefficient energy systems in buildings, some buildings are old and their design (building and services) are obsolete for current standards and presented important issues. Furthermore, current services are not User-Oriented, hence small attention on occupants (e.g. indoor comfort) and occupancy is considered in energy management. Through the application of the design approach the energy saving measures are identified: upgrading of building envelope and lighting elements, substitution of the CAV system with a VAV system and application of occupancy-based smart controls on ventilation, heating, cooling and lighting. According to the energy calculations more than 25% of energy savings can be realized.

Conclusions This project on an existing AMC Policlinic has shown that energy consumers, energy flows and energy wasting components are often unknown, resulting in uncertainty parameters for sustainable energy reduction investments. Furthermore calculations show that the energy performance and indoor comfort can be significantly improved by upgrading the building envelope, the HVAC system (from CAV to VAV) and applying occupancy-dependent smart controls.

ABSTRACT. Toughening requirements for energy efficiency of buildings sets the new challenges to the building owners, designers and contractors. Although nZEB requirements will apply only to the new buildings, Tallinn University of Technology decided to renovate existing student hostel building to nZEB building. Building has same typical problems as many other existing buildings: high energy consumption, insufficient ventilation, overheating during winter, insufficient thermal comfort. Need for major renovation is evident but goal to renovate this building to nZEB building have raised many new challenges. Somewhat surprisingly chose challenges were not so much related to the specific technical problems but more to the overall understanding of the concept of nZEB and managing the design process in order to guarantee that the end result is nZEB building. In general, building owner is in favour of the nZEB, but nZEB renovation should not mean excessive investment costs. Therefore, designers have new challenge to devise nZEB renovation in such way that it is not significantly more expensive than standard major renovation. Our experience revealed that designers have not yet fully understood the whole concept of nZEB buildings and have some difficulties managing the design process in parallel with the energy calculations and cost optimality calculations. The solution which is often used that energy calculations just one solitary part of the design process is no longer suitable in concept of nZEB renovation. Energy calculations and cost optimality calculations must be used in parallel with designing the technical solutions already in the early stage of design.

ABSTRACT. Introduction

In Europe, buildings have been identified as a major responsible for carbon emissions, due to poor energy performances. In this sense, building renovation plays a major role in the reduction of the energy consumption and carbon emissions. Nevertheless, main regulations and standards are mainly targeted to new buildings, lacking in effectiveness when dealing with the existing building stock. These buildings have specific constrains and many times all the changes that are needed in order to meet the regulations requirements, involve expensive and elaborated procedures, difficult to implement and seldom accepted by users and promoters. For existing buildings, the use of renewable energy sources harvested on-site or nearby can be as effective as energy efficiency and conservation measures. It is therefore important to investigate what should be the right balance between energy conservation and efficiency measures and technologies that require the use of renewable energy.

Methods

IEA EBC Annex 56 has created a methodology for cost effective renovation of existing buildings, to help the entities involved on decision making related to building renovation. The methodology uses a life cycle costs approach, and additionally considers embodied energy and the co-benefits (such as improved thermal comfort and air quality) that arise from each possible package of renovation measures, and focus on the packages beyond cost optimality until the limit of cost effectiveness. The present paper aims at presenting the application of the IEA EBC Annex 56 methodology, for cost effective energy and carbon emissions optimization on building renovation, using a Portuguese case-study. The case-study consists of a building which is part of a social housing neighbourhood from the 50’s of the XXth century.

Results and discussion

The methodology was used to compare the implemented renovation solution with other alternative scenarios to renovate the building, including solutions for the envelope and for the buildings integrated technical systems, with and without the use of renewable energy sources. The results show that the implemented renovation scenario is not cost optimal and is still far from zero energy and emissions. The analysed alternative renovation scenarios further improve the buildings envelope, reducing the energy needs, considerably minimizing the risk of overheating in the summer and improving the users comfort conditions and the shift to building integrated technical systems based on renewables allows approaching very low levels of energy use.

Conclusions

Results are consistent with those obtained in several other buildings analysed within the project, showing that cost optimal levels aren’t ambitious enough regarding the goal of reducing significantly CO2 emissions in the building sector and that the smart combination of energy efficiency measures with the use of renewable energy in building renovation is an efficient and cost-effective way of approaching nearly-zero emissions in existing building stock.

ABSTRACT. INTRODUCTION This paper presents results of conducted research of possibilities to reconstruct an old traditional village house providing its residents significantly improved environment concerning IEQ, sanitary water and electricity supply, as well as an access to the ICT networks. Further, conducted research encompasses total building performance simulation and energy efficiency optimization of the reconstructed building for local typical meteorological year (TMY) obtaining its ZFE (Zero Fossil Energy) and healthy IEQ status. The case study house is a traditional rural, one-family house. These houses are mostly located in South and Eastern Serbia, but also in other Balkan areas. They were mostly built in the 19th and early 20th century. Most of these houses are in bad or even non-functional state, without water and electricity supply in the household. As a result of people migration to cities, significant number of these houses is no longer occupied. Houses wall structures are made of the materials that can be found in local environment (wooden skeleton and cob – a mixture of mud, straw, wood chips and sand). Research study objective is to determine strategy, reconstruction means, appropriate RES (Renewable Energy Sources) technologies and whole integrated sustainable building design to turn these buildings status to the contemporary living conditions, and environmentally conscious status preserving local architecture, construction traditions and culture. METHOD Analysis is conducted for the existing building renovated with the reference to its initial state, and for the several scenarios for the RES integrated refurbished house by implementing the BPS (Building Performance Simulation) using Bentley AECOsim Energy Simulator integrated with the EnergyPlus software. Within defined scenarios have been analyzed and optimized different building’s walls structures and materials, HVAC and other technical and RES supply systems. RESULTS It has been shown that implementing integrated sustainable building design, in Central and Southeast Europe, is possible to minimize all relevant energy loads to the level that exclusively RES can be used to satisfy all total energy loads and annual demand. Heating and cooling loads are minimized, HVAC and all other technical systems energy efficiency is optimized, biomass has been selected for heating energy source and photovoltaic (PV) panels are used for the production of energy needs for cooling, lighting, electronics, appliances and hot water supply (HWS). CONCLUSIONS The results show that house deep energy refurbishment enables locally available RES, to be able to satisfy all its annual final energy forms and amounts in local TMY. In terms of the preservation of traditional architecture and environmental sustainability, it is necessary to consider the new houses and renovation of existing ones, with the use of materials with similar composition and properties to the accessible on or near the settlement. The results of the analysis are imposing to proceed the analysis of the current state of the building, its residual life, the total cost of rehabilitation and refurbishment, and the overall impact on the environment through CO2 emission.

ABSTRACT. Buildings have been recognised as key contributor to the energy consumption and emissions worldwide. In the UK, approximately 50% of the non-domestic buildings energy consumption is due to the Heating Ventilation and Air-Conditioning (HVAC) systems. To achieve the EU decarbonisation targets set for 2050 -emissions reduction to 80-95% of 1990 levels- it is important to consider the integration of novel low-carbon HVAC technologies in the built environment. Nevertheless, the selection of HVAC systems is often performed in the early design stages, when there is limited data available regarding the system operation and specification. This uncertainty, combined with a large number of design parameters, significantly increases the complexity of designing HVAC systems.

An effective means of quantifying the uncertainty is the use of Global Sensitivity Analysis (GSA). GSA can identify the most influential variables related to HVAC performance, and focus the system design on these fewer, but most significant parameters. The features of this study, which differentiate it from other available analyses in the literature, are that it deploys GSA instead of the simpler local sensitivity analysis methods, while focusing on the parameters affecting the HVAC system design in non-domestic buildings. The proposed framework combines two GSA settings, namely Factor Screening and Factor Prioritisation. The GSA methods deployed are based on Monte Carlo sampling of the model input parameters. The Morris Elementary Effects method has been used to perform Factor Screening, and the Fourier Amplitude Test and Sobol analysis have been used for Factor Prioritisation.

The usefulness of the proposed GSA framework in HVAC systems design is illustrated through an office building case-study. The results have identified the heat pump and heat-recovery efficiency as the most influential parameters on the system’s energy consumption. These parameters, along with the room temperature set-point are responsible for 95% of the observed variability in the energy consumption. In contrast, parameters such as the pressure drop to be overcome by the fan-coil units (FCUs), and the fans motor/drive efficiency, are found to have little influence on the total system energy consumption. The analysis also provides probability distribution curves of the system’s energy consumption and load, instead of point estimates. These can be used by decision makers to select the HVAC system that meets the design objectives, with a specified confidence level. The results reveal that the heat pump system sized at 80% of the maximum potential peak load point estimate is capable of meeting the peak load of every single hour with 95% probability.

This study gives confidence that GSA can be used in the early design stages of HVAC systems, to uncover the most influential parameters of their performance, based on which further system optimisation can be performed. Therefore, this framework can inform the design of novel low carbon HVAC and power generation technologies, by identifying the key contributors to the system operational efficiency.

ABSTRACT. The transition towards a more energy efficient and environmentally friendly economy is a recognized objective of the European Union. In Germany, this concept is known as “Energiewende” and aims at reducing greenhouse gas emissions, increasing electricity generation from renewables as well as reducing overall energy consumption. In the context of buildings, energy savings can for example be achieved by installing more efficient heating devices and by improving their control strategy.

Currently, most studies using exact optimization methods for computing the optimal design, sizing and operation of building energy systems (BES) rely on large simplifications. Often, the heating device’s nominal powers are chosen from a continuous range between a lower and an upper bound leading to solutions that are not available in reality.

Thus, the aim of this paper is to extent previous works and to present an optimization model that entirely chooses heating devices from a previously defined pool of available, existing devices. In this manner, more information regarding the devices, such as specific efficiency values for each device can be included in the model, leading to a higher modeling accuracy. Furthermore, this approach ensures that the optimal configuration that exists and can be purchased and installed.

The optimization model is formulated as a mixed integer linear program (MILP) using Python as a modeling tool with Gurobi as solver. The model determines the optimal BES configuration by choosing previously defined heating devices and scheduling their operation. The model considers heat generators such as heat pumps, combined heat and power units, boilers, and electrical heaters as well as renewable energy sources like photovoltaic cells and solar thermal collectors. Furthermore, storage devices like thermal energy storage units and batteries are available. The optimization is based on economic incentives, thus minimizing the sum of annualized investments and operating costs as described in the German engineering guideline VDI 2067.

In this paper, we present the results from applying the developed model to three residential buildings significantly differing in size. Furthermore, we analyze the gap between the developed model and a simplified model in which the nominal powers are chosen flexibly within given bounds, not respecting existing devices’ restrictions. We also analyze if this simplified approach can serve for decreasing the pool of available heating devices for our model in order to reduce the computing times.

The results indicate that the difference between our model and the simplified model is between 7 and 13% which increases with the building’s size. This effect is due to the great diversity of available CHP units which are chosen by the optimizer for large buildings. This diversity makes the inherent assumptions of the simplified model invalid, in particular a constant power to heat ratio for all sizes of CHP units, leading to large deviations from the more accurate, developed model. When using the simplified model for tightening the search space of the developed model, the gap between the developed model with full and tightened search space can be reduced to 1 to 5%.

ABSTRACT. In the course of an ambitious initiative within the Vienna University of Technology, an over 40 years old high rise building has been refurbished comprehensively to Austria´s biggest plus-plus-energy office building. This building is located in the very center of Vienna and consists originally of a two level basement and 12 upper stories. The entire building has a net floor area of approximately 13.500m2 and occupies roughly 500 employees. This research focuses on how energy efficiency arrangements influences and effects the design of the entire HVAC system. The constraints for the plus-plus-energy balance (primary energy, non renewable) is including only the building and its surface over an observation period of one year for all energy flows based on Annex 53. This is including the energy needs for both, operation (heating, cooling, ventilation, lighting and domestic water) and usage (computers, servers, all kitchens as well as all electronic appliances) within the 3rd and 10th floor, which are occupied as office use. The overall aim of this project was to achieve a positive energy balance. This leads to the approach that optimizing internal loads are not only reducing the installed cooling or heating power but also decreases necessary area for photovoltaics and the HVAC and increases more space for additional systems or other usages. For instance, the entire 11th floor was a former HVAC room (mainly for ventilation purposes) and can be now used as a conference room with a viewing platform. Those are essential criteria’s by considering cost optimums and facing urban challenges. By considering a passive house optimized building envelope including external shading devices, mainly the internal loads are influencing the cooling and heating demand as well as the thermal qualities. One of the key elements was to reduce the energy need for all working places. This is including all computers, screens, telephones, printers and all network devices. Only this step by step optimization enables less HVAC efforts for both distribution and generation. A single low temperature change-over floor heating and cooling system (within the screed) was installed in the entire office area. Two CO2 appropriated ventilation systems supplies the entire office area with fresh air, using only a double rotary heat exchanger (no heating or cooling device) and efficient ventilators with fan optimizer. Additionally, a natural night ventilation system which is using a former utility shaft, is reducing cooling loads during the transition periods. These systems are getting complemented by Austria´s biggest building integrated photovoltaic power plant. Due to the precisely optimization of up to 9300 building components and an optimized passive house envelope, the primary energy demand (non renewable) was reduced to a minimum. The consequent implementation of those efficiency arrangements enables less HVAC efforts by simultaneously maintaining thermal quality requirements. Therefor an optimized heating, cooling and ventilation demand simplifies the entire HVAC system to meet all challenges and requirements regarding to a comprehensive refurbishment and the overall aim of maintaining a positive energy balance.

ABSTRACT. Introduction From the start of this research aims were set to understand the nZEB definition(s) for the new Dutch building stock and to use this information during an integral design process. The ambitious targets for a new nearly zero built environment are currently rarely met, this because low energy building typically are seen as more costly than a conventional building, but these buildings can be considered beneficial when by a life cycle analysis additional benefits for a higher renting value, PR and better productiveness will be taken into account.

Methods Heating, lightning and ventilation are the largest energy consumers in sustainable office buildings. Lightning is not only about artificial lightning, there are plenty natural daylight systems available to minimize the energy consumption and improve the well-being of the end-user. In the Netherlands almost all sustainable offices applies geothermal ATES systems for heat and cold storage. By this cooling can be achieved with a relatively low energy consumption, which was found in the primary energy demand diagrams of analyzed buildings, and therefore have a lower share of energy use compared to lightning, heating and ventilation.

Results and conclusions The main specifications of the recent nZEB are given, as well is the main characteristics are gathered in a chart. This provides an overview what is possible already with existing technology. This can be an inspiration for others to do not wait but to follow and start with nZEB design.

ABSTRACT. INTRODUCTION The nZEB is mainly defined according to the total primary energy consumption of a building. In modern new office buildings there can easily be thousands or even millions of different energy performance options, especially when the renewable energy production systems are taken into account. This creates a problem in designing of an nZEB, as the selection of cost-effective energy performance measures should always be based on the real use of the building, not solely on the measures to reach the nZEB. The objective of this study was to determine cost-effective energy performance measures in typical new low-energy office buildings built in cold climate. The studied building is located in Tallinn, Estonia and it represents a typical modern office building type built in the Scandinavian countries and in Estonia. METHODS The research method used in this study was simulation-based multi-objective optimization. The energy simulation tool was IDA ICE (version 4.6.2) software and the optimization program used in the analysis was MOBO (version 03b). The target of the optimization analysis was to minimize the present value of 25-year life-cycle costs, with detailed cost data, and the total energy consumption of the building. The metric of energy performance in the optimization analysis was the real target energy consumption of the building with real usage profiles, not the calculated total primary energy consumption with standardized office building usage profiles. Optimized energy performance measures concentrated on the envelope of the building, ventilation systems, solar-based electricity production system, ground source heat pump and district heating systems and lighting systems. The GSHP system was used in both heating and cooling with free cooling utilized, when possible. RESULTS AND DISCUSSION The GSHP system with relatively small dimensioning power output, combined with water-based ceiling radiator panel system used for heating and cooling, VAV-based ventilation systems controlled according to the CO2-concentration and indoor air temperature in almost all space groups, LED-based lighting system without occupancy and constant light control systems and a moderate area of PV-panels proved to be the cost-optimal solution. Other recommendable measures also included good thermal insulation of roof, fairly energy efficient windows for all facades of the building, blinds between the outer panes of windows and energy efficient air handling units. According to the results, the control strategy of the ventilation system had a relatively significant impact on the energy performance of the studied building. CONCLUSIONS According to the study, a borehole implementation of the GSHP system is a more recommendable alternative than the energy pile solution, when energy performance and cost-effectiveness are discussed. The solar-based electricity production system with PV-panels is also a recommendable measure, especially when the nZEB requirements are discussed. Investing in good thermal insulation of roof is also recommendable.

ABSTRACT. This paper deals with the objective of achieving real energy consumption targets and its implication, as opposed to regulatory or labels requirements which are more commonly found. The author describes the case study of Velux China new headquarter which is a high performance office building. The project is a two-storeys building with a gross floor area of approximately 2000m², located in Langfang, 60km South from Beijing, China.

The author has been involved in the project from the preliminary design assessment, design development, construction documents, tender management, construction management, HVAC and lighting systems commissioning to measurement and verification (M&V) period of two years. The assignment was to help the project owner (Velux) ensure that the project would meet the ambitious goal of achieving a final energy consumption of 40kWh/m²/year (not including office equipment) and 60kWh/m²/year (including office equipment). In order to allow the reader to appreciate the difficulty of achieving this target, we remind that local climate features very cold winter (design outdoor air temperature -11°C with siberian winds) and very hot summer (design outdoor air temperature 35°C and design outdoor wet bulb temperature 27°C). The performance target were also defined to allow the project meet financial blance criteria, highlighting the importance of reaching the target in real life. Moreover project management in China often implies challenges regarding quality management. Lastly, the concept design was inspired from the Copenhague Light House project. Daylight oriented design along with the use of TABS (Thermally Active Building Slabs) were planned.

To achieve such objective a work methodology based on the technical requirements of energy performance contracting has been implemented. The author explains for each project stage what were the challenges and successes that have lead to effectively measure an energy consumption which is compliant to the initial goal. He also explains how each project stakeholder has learned along the process. The concept design had to be reviewed and adapted to Chinese context. Secondly the design development had to be done as per the integrated design process methodology to ensure that the potential for energy performance was not missed. The construction documents had to be carefully reviewed and it was decided to split the tender in two parts (HVAC/BMS were separated from the rest because it was too specific and local general contractors were not experienced enough). The tender stage has been done following a competitive dialog scheme to reach optimum balance between technical and economic requirements. Construction supervision was done using the services of the specialized project management company. Then a commissioning period was done by the design team to ensure the continuity from design (how it should work) to reality (how it actually works) and reach functional acceptance. Finally a two years M&V period has been conducted to verify the actual energy performance and help fine tune building operation. IPMVP option D was used.

ABSTRACT. In this paper we address the general topic of calibrating initial Building Energy Performance Simulation models, iBEPS. We build upon a recently published paper entitled ``Narrowing the Gap - A Framework for Connecting and Auto-Tuning a Design BPS Model to a Physical Building" to outline a methodology for calibrating iBEPS models. We highlight common trends and pitfalls encountered in iBEPS calibration studies, and propose strategies and a methodology for overcoming these obstacles. The methodology is implemented and tested on IEA Annex 58 single housing model.

ABSTRACT. Global climate change is one of the most important environmental issues that human have ever faced. China is taking an active role in reducing carbon dioxide emission in order to alleviate the climate change process. Building sectors contribute for 30% of carbon emission and 27.5% of total energy consumption in China. There is an urgent need for improving building energy efficiency to achieve carbon reduction. New buildings are legislated by national standards and regulations to secure a relatively high level of energy efficiency. However, the diversity of architectural design, system operation and management make it a big challenging to achieve energy efficiency in existing buildings. Existing researches have already investigated the building retrofit technologies and strategies. However, information on the current building stocks is even more important due to its impact in decision makings of retrofit strategies. This paper investigates the energy consumption of public buildings in Chongqing, China. Building energy consumption data collected from Chongqing public building energy consumption monitoring platform was analyzed by SPSS software. The data collection and analysis are focused on governmental office, general office, hotel buildings and shopping mall. Statistical hypothesis test, using log-normal P-P plot and Shapiro–Wilk test, reveals that the annual energy consumption densities of these types of building are log-normal distributed.

ABSTRACT. Building energy consumption data can reflect building energy consumption level， evaluate effect on application of energy efficiency technology, enhance building energy efficiency management and promote energy efficiency retrofit in existing buildings. However, there are few research that used data of energy consumption data to analyze electricity consumption characteristics of buildings. The purpose of this paper is to analyze annual, monthly, weekly electricity consumption in air condition system in order to figure out electricity consumption characteristics in air condition system according to different time in office buildings in Chongqing. The distribution of annual electricity consumption can be proved to obey approximately logarithmic normal distribution with Quantile-quantile(Q-Q) method and K-S inspection method. The paper also found distribution law of air condition system at different periods. In 06:00-10:00 period, 18:00-20:00 period in winter and 8:00-10:00 period in summer, electricity load rate of buildings had obvious volatility. And regulation strategies should be decided during these periods. Compared with the load rate of a unit put forward in IPLV evaluation method, this distribution law was carried out characteristics of air condition system operation rather than defined by subjectivity. The method basic on statistical analysis provided in this paper can analyze electricity characteristics of different air condition systems in different areas, make unit capacity consistent with electricity load of air condition systems during design work, regulate electricity unit load depending on dynamic electricity load of air condition system in the process of air condition system operation. The method can supply effective guidance in improving measures of energy efficiency retrofit and making control regulation strategies in air condition system.

ABSTRACT. Theoretically estimated energy savings associated with better energy performance levels are rarely achieved in residential buildings. Part of this is explained by the higher indoor temperatures found at higher performance levels. Literature associates this temperature take-back with physical and behavioral causes: better insulated envelopes result in higher average indoor temperatures and inhabitants increase their comfort expectations and choose more demanding heating profiles in more efficient buildings. However, literature gives little to no proof for different heating profiles being linked to different energy performance levels. To study possible changes in heating profiles and their causes, a statistical study was conducted on survey data and energy performance assessment data on more than 575 houses and their inhabitants: old, non-insulated houses, houses with standard performance levels and high-performance houses. The study reveals significantly longer heating times in centrally heated houses compared to houses with de-centralized heating systems, but only in the bathrooms. The number of heating hours in the living proved to be more strongly associated with the presence of a low temperature heating system or heat pump than with the presence of people. The number of heating hours was not associated with the calculated net space heating and only to a small extent with other technical and socio-demographic data. These findings indicate that more demanding heating profiles do occur in higher performance houses, but mainly as a result of the type of heating system (its control and response time) and less as a result of behavioral rebound induced by the lower cost per demand ratio.

ABSTRACT. A data-driven model is advantageous since it requires less inputs to mimic the dynamics of the reality than the first principles based simulation model. In this study, the authors developed the Gaussian Process (GP) model, one of the data-driven models, to predict the energy consumption of HVAC systems for two existing buildings. In developing such data-driven model, it is important to identify the correlation between inputs and outputs. The occupant behavior and presence were used as one of the inputs to the model. A Normalized Cumulative Periodogram (NCP) and a wavelet coherence were used respectively to investigate the predictability of occupant presence (behavior) and time-series correlation between occupants and energy consumption. It is shown that the GP model is good enough to predict energy consumption; however the model should be updated in real-time to capture the effect of non-stationary occupant behavior and presence.

ABSTRACT. INTRODUCTION The energy use of hospitals is among the highest of all building types. Within this specific group the academic hospitals, the high care hospitals, form a specific group with an even higher energy use. Given the necessity to reduce the energy demand, it is important to look for opportunities to reduce it without endangering the primary functions within hospitals,

METHODS The energy influencing parameters of the HVAC system are quantified using heat loss and cooling load calculations and simulations. Assumed parameters and changing conditions in these calculations are eliminated using a sensitivity analysis.

RESULTS and DISCUSSION This quantitative analysis show internal room temperature and the amount of fresh air supply to be energy consuming factors of the energy consumption. The HVAC energy reduction potential of isolation rooms in EMC is approximated using the Pareto analysis method, which enables to solve the majority of problems assessing the few major causes, called Key Performance Indicators (KPIs). Special focus was on the barrier function within the isolation concept of an intensive care unit.

CONCLUSIONS A energy management study in Erasmus Medical Centre (one of the University Medical Centres that face challenges in defining energy reduction measures) revealed isolation rooms to be a large energy consuming healthcare function. This formed the starting point to define a framework which lead to long-term energy reduction in the complex building systems of UMCs. It proved that there relevant possibilities to reduce the energy use while maintaining the primary function of isolation in the Intensive Care units.

ABSTRACT. Model-based scenario analysis is an effective way to underpin revision of energy codes/standards and assess new technologies rationally. Many studies have been conducted to develop standard building energy models, e.g. reference buildings, and secure the model validity. The reference building is created based on national statistics on building stocks in general. However, the shape of buildings is typically overlooked and thus the shape is decided on the basis of an expert’s opinion. One of the main reasons for this is the lack of a well-defined framework for handling the building shape in a quantifiable way. The building shape is closely related to cooling and heating loads due to the impact of solar radiation and airflows. Hence in order to strengthen the foundation of the reference model framework, it is necessary to address how to create a representative building shape from a building stock. In this paper, the applicability of statistical shape analysis, which is an analysis of the geometrical properties of some given set of shapes by statistical methods, is investigated to estimate representative building shapes and their variations. The coordinate data of building footprints were obtained by Geographic Information Service of the Statistics Korea, and analyzed by statistical shape analysis. Finally, a mean shape of a building stock was derived as proof of concept. The established framework and the usefulness of the results are described in detail.

ABSTRACT. The paper describes the study carried out by ENEA, to provide technical support to the Ministry of Economic Development on the calculation method and the definition of minimum energy performance requirements, in the framework of the implementation of European Directive on the energy efficiency of the buildings (2010/31/EU).A simplified methodology, aimed to evaluate the energy need for heating, by mean simple parameters, is proposed. The energy demand has been estimated through a standardized procedure according to the Italian legislation for energy certification of buildings (D.Lgs. 19/08/2005 n.192 and subsequent modifications and additions. Considering different type of reference buildings (detached house, small and large multifamily buildings) it has been carried out a numerical simulation to calculate the energy need for heating following the quasi-steady-state calculation methods given in national technical standards (UNI TS 11300). The tests were carried out locating the buildings in different reference sites (15 cities), representative of different climatic zones of the Italian climate, and taking into account three different levels of insulation of building envelope. The clear correlation between the energy need for heating and some parameters considered such as, the building shape factor S/V, the overall thermal transmittance and the degrees-day of the site, has allowed to derive a simplified relation, based on regression methods, to evaluate the energy demand for the whole set of buildings models. Regression analysis has showed the goodness of fit of the model, and has been highlighted the possibility of using the simplified procedure for the estimation of the energy performance in different conditions, as a function of degrees-day, shape factor, and overall thermal transmittance. The linear regression model was also applied to an office building, in order to evaluate the effectiveness of model to different building types,. The test has showed a good linear correlation, but the different trend observed, compared to the previous cases, suggests considering non-residential buildings separately. The method proposed can represent an useful tool, not only to estimate the energy demand for heating, but also, for the legislator, in phase of definition of the thermal characteristics of the building envelope, allowing to verify, in a quick way, as the variation of few main parameters, can modify the energy demand of building. Further studies are needed to analyze the non-residential sector, which includes many different types of buildings, and to assess the possibility of application of regression models for estimating the energy needs for cooling.

ABSTRACT. Recently, VRF systems have become prevalent in Japanese small and medium-sized buildings. It is important to understand the performance of operating Variable Refrigerant Flow (VRF) systems; however, this is still unclear. Therefore, we proposed method to extract the typical partial load characteristics for find a relation between the load factor and Coefficient of Performance (COP) of VRF system under arbitrary operating conditions. This paper reports that we developed method to extract the typical partial load characteristics for Electrical Motor-Driven (EHP) VRF system and show a result used this way. Partial load characteristics is grasped by making a scatter diagram using COP and the load factor. However, if it's the case, COP becomes the curve becoming “0” at the time of high loads and cannot extract the typical partial load characteristics. Therefore, we thought that they could extract the typical partial load characteristics when they calculated the median of COP every partial load in the outdoor unit. First, we calculated the median of COP in the partial load factors "5 ± 1 %, 10 ± 1 %, 15 ± 1 %,･･･". I thought the one which supposed the median of this COP as COP of partial load factors "5 ± 1 %, 10 ± 1 %, 15 ± 1 %,･･･" in the typical partial load characteristics, made a scatter diagram and made approximation of curves by method of least squares using a scatter diagram was the typical partial load characteristics. I show the result that I extracted using data in ten EHPs where the typical partial load characteristics was measured by our laboratory. I found that cooling in high efficiency when compare heating with cooling. Then, the typical partial load characteristics was extracted every outside temperature and it was compared. Cooling was divisible into 21-25 ℃, 26-30 ℃ and 31-35 ℃, and heating was divisible into 0-4 ℃, 5-9 ℃ and 10-14 ℃. COP of cooling goes up when the temperature falls, and COP of heating goes up when the temperature rises. Then, I compared COP of the outdoor units which I measured after 2010 and the outdoor units which I measured before 2009. COP of cooling slightly has efficient after 2010 units. When compared COP every temperature, I found that COP of cooling in the outdoor units after 2010 is very efficient. I found that an outdoor units after 2010 was efficient in a high load of more than 80 % of load factor in heating. However, an outdoor units before 2009 was efficient in a high load of less than 80 % of load factor in heating. When compared COP every temperature, I found a similar result in heating. I proposed this extracting method to understand the performance of EHP. I think when I can use the characteristic made with this extracting method for a comparison with the efficiency of other heat sources or the simulation of VRF systems.

ABSTRACT. Thermal building simulations are widely used in R&D projects in civil engineering. They are applied for the evaluation of the building’s heating and cooling demand, for the optimization of HVAC and building constructions, development of model predictive control strategies etc. It is common that as an input data for the simulation standard schedules of the occupants’ presence, equipment usage, lightning and ventilation are used. However, generally unpredictable occupants’ behaviour can influence on each of the schedules listed above and therefore affect overall energy demand and most importantly - the heating and cooling peak loads during the day. Taking such impact on the thermal building models into consideration can improve the reliability and accuracy of the final simulation results and assess the value of their uncertainty. The aim of the present research is to evaluate the impact of the occupants’ behaviour's uncertainty on the heating and cooling load of a typical building. Furthermore a method to account such effect on thermal building simulations is presented. For this task a typical Swiss four-storied residential building with 8 flats is modelled and simulated for a 1 year period. Each type of the flat’s room (living room, kitchen, WC and bath) was evaluated with a set of 4 schedules: occupancy, equipment usage, lightning and ventilation. Average schedules and their uncertainty (deviation range) were taken from the Swiss Standards for Engineers and Architectures. However, it is not likely that upper or lower boundary schedules occur during the whole day; hence, schedules' randomization is needed. For this purpose a normal Gauss distribution was applied for each time section of the standard schedules. In total 102 schedules were used for the thermal building simulations including upper and lower limit schedules. Such method, which involves repeated simulations with randomized input parameters, is known as Monte-Carlo method. The results show that the variance of total heating and cooling demand equals to 20 % of its absolute average value, although peak heating and cooling loads vary within the range of 40 % to its absolute average value. It should be mentioned that the influence of the user's behaviour would be greater if investigated building is lightweight. The results of simulation were compared with the annual measurements of energy consumption of a residential building. The comparison shows that the impacts of user’s behaviour on energy consumption of the real and simulated building are similar during the day and have the same order of magnitude.

ABSTRACT. Introduction As a consequence of the EPBD, Flanders, as other EU Member States, has set up an energy performance certification (EPC) system for existing buildings, being mandatory when selling or letting a house. In Flanders, the EPC gives the energy rating of a house in kWh/m² floor area, calculated based on detailed housing characteristics. Between 2008 and 2013, 617.489 EPCs have been registered, representing 28% of the current dwelling stock and also representing a magnitude of detailed data on Flemish dwellings. At the same time, in order to meet the EU2020 objectives, the Flemish government has set up different policy programs to stimulate energy renovation with the objectives that all houses should have roof insulation, double glazing and an efficient boiler by 2020 and that all buildings should have a maximum energy rating of 100kWh/m² by 2050. The research question for this paper is to which extent the EPC database could inform on the energy performance of Flemish houses and serve as a basis for policy actions related to the objectives of these renovation programs. Methods First the main characteristics of the houses in the EPC database were determined with a statistical analysis with regard to energy rating, housing type, geometry, insulation, type of glazing, heating systems, etc. To investigate the representativeness of the EPC database, a comparison was made with the Flemish land register, an Eurostat survey on 1000 houses and a large scale Flemish housing survey among 10.000 households. Finally, the current state of the dwellings in relation to the objectives of the renovation programs was calculated both for the EPC database and the two surveys. Results and discussion Despite the richness of the data, the EPC database cannot be considered as fully representative for the Flemish dwelling stock. The distribution between apartments and single family dwellings is quite different and also for the building type and construction year there are differences between the EPC database and the other data sources. With regard to the presence of insulation, the EPC database in general gives an underestimation compared to the two surveys. This can be due to the EPC inspection protocol that requires specific documents to prove presence of insulation. Otherwise, default values related to the construction year, have to be used. The analysis showed that most EPCs rely on these default values, also because they make the EPC assessment less time consuming. More detailed results will be presented in the paper. Conclusions Despite the fact that the EPC database is not completely representative, it is clear that up to now too few houses (only 8%) meet the requirements of the renovation programs. Yet the database contains very detailed data on each of the houses and is already connected to a steady state energy simulation software program. If this could be extended with a cost-benefit calculation tool, this could be used to set up a renovation advisory tool in which the house owner or the architect could investigate different renovation scenarios by means of comparative energy and cost calculations.

ABSTRACT. In most HVAC installations, the ductwork layout, i.e., the network structure of the ducts, as well as the number and locations of the fans, is an important determinant of the installation's cost and performance. Nevertheless, the layout is not explicitly taken into account in existing duct design methods such as the equal-friction method, the static regain method, or the T-method. All existing methods assume the layout of the air distribution system to be predetermined and focus solely on the sizing of each fan and duct in the system. The layout itself is usually determined using rules of thumbs and heavily depends on the knowledge, experience and judgement of the design engineer in charge.

The layout of an air distribution system influences the optimal duct and fan sizes and vice versa. Both are interrelated decisions that jointly influence the installation’s performance, energy consumption, material cost, operating cost, etc. The overarching aim of this research is to extend previous research by developing a design method that is able to calculate the optimal air distribution system configuration, i.e., the optimal ductwork layout and duct and fan sizes, taking into account constraints imposed by the building structure, customer requirements, etc. One of the prerequisites of such a design method, and the subject of this paper, is an efficient simulation model that is able to quickly quantify the cost, performance and feasibility of a given air distribution system configuration. The simulation model proposed in this paper is developed in EES (Engineering Equation Solver), and can simulate large air distribution systems with an arbitrary layout and complexity. Besides the ductwork’s material cost, the model determines, a.o., the required fan pressure and the total pressure loss in each path of the ductwork layout. In practice, the material or installation cost is still one of the key decision parameters in the design process, whereas the last two parameters give an indication of the energy consumption of the air distribution system. The simulation model can also be used to study the effects of variable flow on the duct design. The development of the design tool that will use this simulation model to optimize the air distribution system layout and configuration is outside the scope of this paper.

In this paper, the simulation model is used as well to calculate different air distribution system configurations in one small non-residential building. This test case demonstrates specifically the significance of the ductwork layout as this is new compared to existing duct design methods. Even for a small building, the differences in material cost (up to 20 %) and fan pressure (up to 25 %) are clearly noticeable. The same applies to the pressure balance of the different layouts. Since the impact of the layout will increase with the size of the building, it is clear that the HVAC sector would benefit from a design method that integrates the layout decisions as well as the sizing of the ducts and fan(s).

ABSTRACT. Most of the calculations of pressure losses for HVAC (heating, ventilation, and air conditioning) fittings in networks are based on data, from sources which are over 60 years old. A large part of existing-literature data for pressure drop coefficients are also only valid for high Reynolds numbers, i.e. larger than 200000. This Reynolds number range is often not applicable for HVAC systems. Therefore, new and adequate studies are needed to achieve efficient ventilator operation and avoid energy waste. The objectives of this paper are to present a comparison between the updated data and the literature and to show the Reynolds number dependency of the pressure drop by means of CFD simulations. The results of the simulation study illustrate the influence of the cross-sectional shape (circular, rectangular, oval and ellipse) on the pressure drop at 90° fittings for different radiuses of curvature r over diameter D ratios r/D. The results show that fittings with circular cross sectional shape do not have the lowest pressure losses. The investigation concerns circular ducts with a diameter D = 300 mm within the velocity range 2-8 m/s as standard case. The dimensions of the other cross-sectional shapes have been determined in such a way that the volume flow rate remains the same as those for the circular fittings of the standard case.

ABSTRACT. Desiccant dehumidifiers can be combined with refrigeration vapour compression systems, evaporative cooling systems, solar systems or waste heat systems to reduce and control the humidity ratio in buildings and certain industrial processes. These combined systems are referred to as hybrid systems. Many studies about hybrid systems with desiccant wheels, DW, have been carried out. In these hybrid systems, a significant energy consumption is required for thermally activate the DW. A DW integrated into a hybrid system can be operated at low regeneration temperatures, reaching acceptable desiccant capacities. Values below 60°C were considered low regeneration temperatures and values above 60ºC were considered high regeneration temperatures in this study. The objective of this work is to study empirically the moisture removal capacity, MRC, of a DW activated at low and high temperature. A low temperature activated DW could be integrated in refrigeration vapour compression systems, evaporative cooling systems, solar systems or waste heat in a building or industrial environment. The methodology used is based on the statistical technique of design of experiments, DOE, which allows to study the behaviour of DW with a reduced number of experimental tests. First a DOE was carried out for low regeneration temperatures, from 34 to 42°C. Then, a second DOE was carried out for high regeneration temperatures, from 70 to 80°C. Both DOEs were conducted varying the air process inlet temperature and humidity ratio and the air regeneration inlet temperature and humidity ratio. MRC maximum values achieved for low regeneration temperature were 9.5 kg/h. MRC maximum values obtained for high regeneration temperature were 19.9 kg/h, 52% difference. In both cases, MRC maximum values were reached for high values of air process humidity ratio and high values of air regeneration temperatures. For MRC maximum values, the air process outlet temperature with low regeneration temperature was 36 ºC. A regeneration temperature of 52.5 ºC was obtained with high regeneration temperature, 31% difference. Experimental results showed acceptable MRC values when a DW is integrated in low temperature activated systems.

ABSTRACT. Intro: One possible way to provide heating or cooling for buildings is to use Air Handling Units. The AHU are equipped with heat exchangers to transfer energy to the supply air. A common AHU has three heat exchangers in line (two for heating and one for cooling). While air is passing through the heat exchangers, pressure losses occur at each heat exchanger regardless of its operating state. However, there are many periods throughout the year where one or more heat exchangers are not required. During these periods it would be advantageous to bypass a part of the air around the unoperated heat exchangers so that the air pressure drop is reduced. To minimize the overall energy consumption the size of the bypass needs to be optimized regarding the operating hours. Therefore heat exchangers with and without bypass were investigated by means of experiments and simulations. Method: To optimize the overall package a new tool is developed, which considers the thermal and fluid-dynamic properties of a variably configurable heat exchanger. Furthermore, the tool provides information about the operating hours of all heat exchangers (in the AHU) based on weather data and expected usage profile. Based on these results, an optimally sized heat exchanger with an optimally sized bypass is calculated according to the expected operating hours. To verify the calculations, two heat exchangers (with and without bypass) were tested at different flow velocities. Results and Discussion: The annual operating time of the studied AHU is approximately 5.600 hours. An analysis of the actual operating hours of the individual heat exchanger has revealed that the first heater is in use 1.201 h, the cooler only 1.224 h and the re-heater is operated 3.042 h per year. The results show for a bypass solution annual energy-saving potential up to 43 % and a reduction in material cost up to 25 %. The application of a bypass has a calculated payback period shorter than four years. Conclusion: In this study the optimized application of bypass dampers for heat exchangers in air handling units is shown to be energetically and economically profitable. Resulting from these outcomes, it is most likely that heat exchangers with a bypass would be of advantage to most systems, even though additional costs for the bypass hardware have to be taken into account. However, regarding todays technical guidelines the application of a bypass is always a disadvantage. For example, in German regulations the energy efficiency is rated at the design point considering the maximum air flow resistance. Subsequently, the SFP value (specific fan power in Ws/m³) is worse than for conventional heat exchangers. At this point the question arises whether the current legal requirements need to be reconsidered as a higher-grade calculation method evidently shows annual energy savings.

ABSTRACT. The development in home energy systems increasingly forces the investigation of new control systems for single room heating control. In Germany the most common way to control the temperature in a room while heating is to use a thermostatic valve in combination with a radiator. The user can define a set temperature and the thermostatic valve reduces or increases the volume flow to adapt the heat output of the radiator. This temperature control system is self-sustaining but has no possibility to communicate to the heating system or other devices in the household. New electrical valve actors are designed to control the room temperature and to communicate with the home energy system. Their use is still in a developing state, and especially new investigations have to be tested in controllable surroundings.

Therefore, a hardware-in-the-loop test bench for hydraulic network applications was developed at the E.ON Energy Research Center. This test bench allows analyzing the operating behavior of radiators and hence testing new control systems and the appropriate components in a controllable surrounding under dynamic boundary conditions. The test bench consists of four rooms, which are heated with radiators. The hydraulic network resembles the one in a small flat. These four rooms are coupled with a dynamic simulation in Modelica, which creates realistic and dynamic boundary conditions for the radiator. The heat supply unit, the type of building and the weather can be changed easily in the simulation setup.

To reduce the required space for the test bench we reduce the enclosing volume of the radiator to about 3 to 4 m³. The boundary conditions influencing the heat emission of a radiator are the surface temperatures of the enclosing walls and the room’s air temperature. These boundary conditions are calculated in Modelica and emulated at the test bench. We use the measured heat emission of the radiator as boundary condition for the simulation.

In this paper, the coupling with the simulation and the test bench is described. The room temperature and wall temperature of each simulated room influences the heat output of the radiator in the test bench. Because of the decreased volume around the radiator, the temperatures have to be converted to the right boundary conditions. The verification of this parametrization is shown with comparative measurements in a test bench with real sized dimensions. Finally, the dynamic behavior of the test bench is shown with the emulation of simulated boundary conditions.

ABSTRACT. The objective of this study was to propose a control method with ventilation requirement of variable air volume (VAV) system in multi-zone. In order to control the VAV system at multi-zone, it is essential to control terminal unit installed in each zone. A VAV terminal unit with conventional control method using fixed minimum air flow can cause indoor air quality (IAQ) issue in winter. This research proposes control method with ventilation requirement of VAV terminal unit in multi-zone. And the conventional and proposed control algorithms were compared through a TRNSYS simulation program. The integrated control method with an air flow increase model in the VAV terminal unit, AHU and outdoor air intake rate increase model in the AHU was based on the indoor CO2 concentration. The proposed VAV terminal unit control method satisfies all the conditions of indoor thermal comfort, IAQ and stratification. An energy comparison with the conventional control method showed that, the method satisfies not only the indoor thermal comfort, IAQ and stratification issue, but also reduces the energy consumption.

ABSTRACT. INTRODUCTION Heat exchanger (HX) in general is a distributed parameter system described by a set of partial differential equations. Analytical solution is often not available and therefore numerical procedures are employed. Typical numerical solution method is method of lines, where the spatial variable is discretized into finite elements, spatial derivatives are approximated by finite differences and the resulting system of ordinary differential equations is integrated in time by available integration solvers. Finite difference approximation, however, introduce artificial numerical diffusion to the solution, which for convection drive processes, like HX, results in information flow being faster than the speed of convection itself. The paper proposes HX simulation model having the information propagation speed matched to the speed of convection. Fan coil unit is modeled in the paper and it is used as an example to show the proposed method. METHODS The proposed model uses discretization of metal body and water column into N and N+1 elements respectively. The state vector comprised of the element temperatures is appended by a water column propagation state, which amounts for "shifting" of water elements along body elements. Heat exchange between elements varies according to the propagation state, which in turn is a function water flow. Information, read sharp temperature changes, then propagate through the system with the speed of flow and not faster. The only peculiarity of the approach is, that element temperatures may be sampled only when they travel exactly one length of an element. This is best visualized at the last water element which exchanges heat and changes its temperature up until it completely leaves the HX. In other words the continuous system is sampled for output in discrete events not equidistantly in time but equidistantly in space. Such a system can be represented by a hybrid model formalism and is given in the paper. A simplified discrete-time model, under the assumption of constant inputs between sampling instances, is also given in the paper in a state-space form. RESULTS Simulations of the model show no numerical diffusion, as opposed to finite differences, and true convectional character of the water stream. Validation against laboratory data of a GECO UW11 2-pipe heat exchanger is given and the model shows, after heat exchange coefficient and heat capacities identification, a surprisingly good fit of the water outlet temperature in the steady state and dynamics in the whole range of water flows. The outlet air temperature shows minor differences in steady state, mainly caused by inaccurate heat exchanger coefficient fitting. CONCLUSION A simulation model of a water-to-air heat exchanger with the focus on a true convection behavior has been proposed. The model is given in a hydrid system formulation or under additional assumptions in a familiar discrete time state space form. Simulations show no numerical artificial artifacts included in the solution and validation against laboratory data shows the model's compliance with a real FCU.

ABSTRACT. There is a need in the heat exchanger industry for accurate guidelines in the heat exchanger design phase. These guidelines can be used to predict the thermal/fluid performance of the heat exchanger that will be manufactured. Accurate prediction for the heat exchanger performance will avoid the cost needed for performing tests in terms of facility and man-hour costs on the heat exchanger prototype before the mass production. Therefore, this paper is devoted to study the thermal/fluid properties on typical compact heat exchanger, which can be found in many HVAC industrial applications. We used the CFD tool to study several factors that can affect the heat exchangers performance, such as the fins spacing and flow inlet velocity conditions. For each of these factors, we estimated the heat transfer rate and the pressure drop in the heat exchanger with the aim of providing an optimum heat exchanger configuration and flow inlet conditions that will provide an enhanced heat transfer rate and reduced amount of pressure drop.

ABSTRACT. Maintaining an ice arena with good quality of an ice over the surface and keeping it as uniform as possible is huge energy consumer. The ice arena also consists of many HVAC systems with differencing demands and specific technologies. To save energy is necessary wherever is possible and the heat recovery from the refrigeration system offers interesting possibilities. The cooling in the ice arenas in the Czech Republic is predominantly ensured by a refrigerant compressor units. In the steam compressor cooling cycle the waste heat rises in several temperature levels. According to the waste heat temperature the options of utilization in an ice arena are discussed and evaluated in the paper. Also measured energy consumptions and experiences with operating of the ice hockey arenas will be presented in the paper. The most efficient and cheapest solution detected from the evaluation in the local ice arena is to recover a superheat vapour from the compressor displacement. The utilization is mainly for melting a snow pit, technological water heating, hot domestic water preheating and for subfloor heating. To cover the energy needs there is usually enought of waste heat in the autumn and in the spring period of the season. Because of lower cooling demand of the ice sheet during the winter the amount of waste heat decreases and as a consequence the primary energy sources must be used. In comparison with utilization of superheat vapor of the compressor displacement the utilization of a condensation heat entails a lot of expensive equipment. This is caused by a huge amount of the low temperature condensation heat. To make the heat usable its temperature has to be increased by a heat pump. Also the requirements on the volume of accumulation, piping and pumping work are much higher and therefore more expensive. This solution is not often used in the Czech Republic so far. The highest used amount of energy consumed by all the HVAC systems is the one using for cooling the ice sheet. Conveniently the waste heat from the refrigeration system can be reused for practical purposes. The refrigeration heat utilization leads to energy savings in hot water preparation system, in melting snow pit and also in subfloor heating. If the condensing heat would be reused the energy savings can be also extended in a space heating, preheating ventilation air and in a dehumidification system.

ABSTRACT. INTRODUCTION In HVAC components and other mechanical devices like heat exchangers, heat transfer by natural convection in vertical channels has an important impact on the performance of the system. Typical heat radiators for example deliver approximately two thirds of their heating power by convector channels. Enhancing the heat transfer in such channels yields a significant improvement in performance. As the flow is often laminar, the heat transfer at the walls is low, because the temperature boundary layer has a comparably low temperature gradient normal to the wall. The main heat transfer mechanism in the stable laminar flow is conduction. In this study, a new method of enhancing the heat transfer in heated vertical channels is presented. Vortex promoters are introduced into the flow, leading to Kármán vortex streets. The vortices separating from cylinders and other blunt bodies lead to a convective mixing of the flow, bringing cooler fluid from the center of the channel to the heated walls and thus increasing the temperature gradient and by that the heat transfer.

METHODS In a test facility with a vertical channel of 640 mm height and 42 mm width and a 2D-extension of 470 mm, heat delivery measurements are carried out with different cylinder geometries, like circular of different diameters, semi-circular etc. Also, different channel positions with regard to installation height of the cylinder are investigated. The heat is delivered via aluminum plates of 3 mm thickness, which are connected to synthetic capillary tube mats. All measurements are done with a fixed surface wall temperature and in a temperature-controlled climate chamber to ensure comparability. The flow is visualized with fog and PIV data is presented.

RESULTS and DISCUSSION Heat transfer enhancements of up to 20.6 % are found with a circular 2D-cylinder with a blockage ratio of 0.60. Promising installation heights are found in the first third of the channel. An influence of the cylinder shape is discovered, leading to a differentiation of geometrical and effective blockage ratio. Flow visualizations and PIV data show, that although due to the 2D channel geometry the flow is assumed to be two-dimensional, 3D structures are observed. The vortex street is of strongly irregular topology. Vortex streets are observed for temperature differences between heated wall and ambient air of 45 K, as well as 25 K and 15 K.

CONCLUSIONS In this experimental study, heat transfer enhancement of free convection flows in heated 2D-channel is found to amount to up to 20.6 % through triggering a vortex street by positioning a cylinder in the flow. The enhancement is achieved without adding any additional propelling energy, as the flow is purely driven by natural convection. The flow is found to be three-dimensional despite two-dimensional geometry. Further studies need to be done with multiple cylinder configurations and 3D channel geometries. The obtained data is suitable for validation purposes of CFD calculations.

ABSTRACT. A desiccant enhanced evaporative (DEVap) cooling system has been introduced recently using at least vapor compression technology. The main components of a DEVap cooling system are DEVap unit, regenerator, cooling coil and reheating coil. This system is based on variable air volume system to deal with space load and it requires specific outdoor air intake strategies according to the outdoor air condition. A DEVap unit cools and dehumidifies the process air to control the room condition and cooling coil conducts extra cooling when the humidity ratio of the air is extremely high. A liquid desiccant and evaporative cooling-assisted 100% outdoor air system (LD-IDECOAS) which uses non vapor compression technology consists of liquid desiccant, indirect and direct evaporative cooler and sensible heat exchanger. The purpose of this research is to compare energy performance of a DEVap system and applicability with those of a LD-IDECOAS system by simulation. The operating energy consumption will be estimated using TRNSYS 17 integrated with commercial equation solver (EES). In terms of fan energy consumption, LD-IDECOAS will consumes more energy because of pressure drop caused from each component. For the regeneration of solution, LD-IDECOAS will require more natural gas because it introduces 100% outdoor air in cooling and intermediate seasons. In heating season, LD-IDECOAS will save heating energy using double stage sensible heat exchange between outdoor air and exhaust air with sensible heat exchanger and indirect evaporative cooler.

ABSTRACT. This study investigated the removal effect for particles and volatile organic compounds (VOCs) in liquid desiccant dehumidifier through experiments. In liquid desiccant dehumidifier, outdoor air is dehumidified by directly sprayed lithium chloride solution. Removal efficiency was used to evaluate the ability to capture airborne particles and VOCs. Particles larger than PM 2.5 in ambient air and two representative VOCs, formaldehyde and toluene, were considered. The contaminants concentration was measured at inlet and outlet stream of liquid desiccant dehumidifier. The removal efficiency was calculated when the process air containing contaminants bypassed and passed through packed bed of liquid desiccant dehumidifier respectively. The flow speed was set to 1.9 m/s, acceptable airflow speed of ASHRAE standard 52.2. The condition of process air were constantly maintained at 28-31 degree Celsius of temperature and 52-53% of relative humidity during experiments. Particles were analyzed according to its size range: PM 2.5-5, PM 5-10, PM 10-. The results of experiments showed that the better capturing ability can be expected for larger particles. Overall particle removal efficiency represented 43.9%, 56.1% and 70.5% in size range of PM 2.5-5, PM 5-10, PM 10- respectively. Overall VOCs removal efficiency showed 28.7% and 23.9% for formaldehyde and toluene respectively. When particle removal efficiency is converted to MERV (Minimum efficiency reporting value), liquid desiccant has similar filtering efficiency to filter of MERV 8 which is typically applied to commercial buildings.

ABSTRACT. In this study, radiant to convective heat transfer split of a hybrid heating system investigated experimentally in order to obtain energy-optimum split while operative temperature was kept constant. Operative temperature is fundamental metric of thermal comfort temperature and it is a function of mean radiant temperature and dry-bulb air temperature. Experiments were conducted in a special test chamber that was set up according to ANSI/ASHRAE Standard 138. Interior surface temperature of each wall and air temperature of the test chamber can be controlled independently. Electric fan heater and radiant floor heating were hybridized with different capacities. To obtain optimum radiant/convective split; operative temperature were kept constant for a data set, radiant and convective systems were simultaneously operated with different capacities. According to the results, optimum radiant/convective split interval is obtained between 0.65 and 0.75.

ABSTRACT. The object of this research study was to investigate the energy saved of 5 different constructed air-to air heat and energy exchangers in three in different weather (high, moderated and low temperature regions) European countries. Using the ambient temperature, enthalpy duration curves, detailed mathematical expressions are presented to determine the annual cooling energy saved by air-to-air heat recovery and energy recovery units. The three different climate cities are: Palermo (Mediterranean zone), Krakow (temperate zone) and to Helsinki (cold climate). The investigated heat recoveries that are suitable only for heat transfer were the fixed-plate heat exchanger, the run around coil and the heat-pipe technology. Energy exchangers allow heat and moisture transfer with higher moisture transfer effectiveness by a sorption rotor and with lower without sorption coating. The results of the calculations show that the largest energy saved can be performed during the cooling period by the energy exchanger with sorption coating. Based on the results the amount of the cooling energy saved is 16-17 % in Helsinki, 31-32% in Krakow and 43 % in Palermo compared to ventilation systems without heat or energy recovery based on this study. Using the developed method it is easy to see that during the selection of heat-and energy recovery units when a ventilation system is designed, the energy saved of the units have to considered not only for heating, but also for cooling period depending of the climate location.

ABSTRACT. This work presents a method to make use of gridded historical mesoscale datasets for energy and hygrothermal building modelling and simulation purposes by transforming, merging and formatting them into time series. The main result of this work is a web tool, https://rokka.shinyapps.io/shinyweatherdata, allowing users to create actual climate dataset for any location in North Europe in file formats used by common building simulations tools. A review is conducted on freely available gridded mesoscale datasets/model systems for north Europe: the modelling systems MESAN and STRÅNG currently used as data source for the developed web tool as well as the SARAH model system and MESAN/MESCAN reanalysis datasets.

ABSTRACT. Metro of a metropolitan city is a traffic node and have big impact on the use of city land, urban development is concentrated upon the city railway stations. Previous studies on categorizing subway station have been conducted based on land use patterns, urban spatial structure and the number of people who use subway station, so studies on categorizing subway station by energy consumption are not enough. The purpose of subway system is easing traffic congestion, so many people use subway system. Especially, subway stations are located in crowed area. In corwed area, people cause a lot of energy, so measurement of energy consumption is useful to categorize subway stations. Therefore, for categorizing subway stations, this study clarify characteristics of each of stations and implement factor analysis and cluster analysis. In addition, the study analyzes categorizing subway stations.

ABSTRACT. In this study, we integrated a photovoltaic (PV) system, a double-skin structure and a thermal flow mechanism to design ventilated building-integrated photovoltaic (BIPV) curtain walls that can autogenously control an environment using buoyant force. Full-scale experiments were conducted to investigate the flow pattern characteristics for the channel airflow and the thermal performance of the ventilated BIPV curtain walls under various heating conditions, wall thicknesses, and types of openings.

The results show that the developed ventilated BIPV curtain walls effectively removed their solar heat gain while maintaining adequate wall thermal performance. The indoor heat gain and the overall heat transfer coefficients for the tested prototypes with a fully open outlet and the louver outlet were very low. For the cases with a fully open outlet, the overall heat transfer coefficient was between 0.11 and 0.14 W/m2 K and was not significantly affected by channel width (i.e. wall thickness) and solar heat flux. For the cases with the louver outlet, the overall heat transfer coefficient was approximately between 0.19 and 0.25 W/m2 K. The electrical efficiency of the ventilated BIPV modules was 16-44% higher than that of a conventional BIPV (in which PV panels are directly attached onto the RC exterior wall of a building) under normal heat flux conditions.

ABSTRACT. 1. Introduction Real energy performances of buildings depend on deterministic aspects, such as the building's physics and the HVAC systems, and on stochastic aspects such as weather and occupants behavior. Typically, occupant behavior is not well handled when calculating expected performances. As a consequence, discrepancies between real and expected energy performances of buildings were showed in field test studies all over Europe. In order to bridge this gap, stochastic occupants’ behavior models should be embedded within buildings’ energy performance simulation software. 2. Methods In this work, a method to analyze the probability of a state change of the windows, based on logistic regression, was applied to the monitored data (measured each minute) from two refurbished buildings. The five rooms of each of the 60 apartments located in the buildings were monitored in terms of air quality and thermal conditions during four years. Further, a weather station collected the solar radiation, outdoor air temperature and relative humidity, wind speed and direction. The aim of this work was to investigate which drivers lead occupants to interact with windows through opening and closing actions, and how these actions can be modelled. 3. Results For each window from the 5 rooms of the 60 apartments, following drivers for the opening and the closing action were analyzed: room air temperature, relative humidity, carbon dioxide concentration, daily average ambient temperature, ambient humidity, time of the day. The evaluation showed that the most common driver to open a window is the time of the day, followed by the carbon dioxide concentration and the room air temperature. The most common influencing driver to close a window is the daily average outdoor temperature, followed by the time of the day and the carbon dioxide concentration. An example of a logistic regression model is finally discussed. 4. Discussion The logistic regression was confirmed to be a strong and robust analyses methodology to investigate the drivers for occupants to interact with the built environment. The strengths of the models are related to the high time resolution of the data, the use of an indoor air quality parameter as explanatory variable, and the distinction of the room use typology. The weaknesses are mostly related to the lack of data related to the presence of occupants. Through the logistic regression analysis, each window was modeled singularly. Thus, 300 models were generated. In order to reduce the number of models, but including the occupants' diversity, the use of a generalized linear mixed effect logistic regression model is recommended for future works. 5. Conclusion The results of the logistic regression identified the drivers for occupants to open and close windows. The main drivers for opening of windows were time of the day (for more than 80 % of the modeled windows), and the indoor carbon dioxide concentration (for almost 60 % of the modeled windows). The main drivers for closing windows were the daily average outdoor temperature (in more than 70 % of the modeled windows) and the time of the day (for more than 50 % of the modeled windows).

ABSTRACT. An important task in design of near zero energy buildings is to decrease the energy need for mechanical fan power without compromising the quality of the indoor climate. This can be accomplished by proper use of natural or hybrid ventilation control by the building management system. However, natural ventilation is often deselected already in the early design phase and one important reason is the lack of an appropriate design tool. Therefore this paper presents a way of integrating simulation of natural ventilation in the early design phase. To estimate natural ventilation, even simplified simulations need inputs of wind pressure, buoyancy force and pressure drop through openings. All these inputs are highly affected by the building geometry which is constantly changing in the early design phase, leading to an unsure and time consuming process. Especially the wind pressure can be difficult to estimate according to changes of geometry. To make it even more complex the wind direction is also changing through the year and good building design offers efficient ventilation at all time. Therefore the simulation of natural ventilation needs to be integrated in annual hourly based building simulation of energy performance and indoor climate, and in a way that is more flexible according to the changing building geometry. First this paper discusses the most important geometry to consider in the early design phase when implementing simulation of natural ventilation in an hourly building simulation. The discussing is based on a step-by-step sensitivity study of the annual building performance estimated by hourly building simulations of a typical office room with a variation of wind pressure coefficients and pressure drop calculated for different variations of building geometry. The annual performance is evaluated according to energy need as well as thermal comfort and indoor air quality. Finally the paper presents a case of a building optimization using the final integrated simulation of natural ventilation. Indoor air quality is the most affected with changes up to 45 % when changing the wind pressure coefficient caused by changes in overall building shape or surroundings. Less important are changes in pressure drop caused by changes in size of the window and changes of wind pressure caused by changes in roughness of the facade surface which only change the estimated air quality by 5 %. Often the surroundings are given in the location of the building project and the architect has already decided on the concept of the overall building shape. Leading to the typical freedom to optimize is often room and facade geometry which has less impact on natural ventilation in annual building simulation. Therefore simulation of natural ventilation in annual building simulation can be applied on a huge variation of facade geometry with the same wind pressure coefficient only considering the overall building shape and the surroundings. In this way, it will be easier to consider natural ventilation in the early design of the building envelope and the final case study shows how efficient facade design can be optimized with the integrated simulation.

ABSTRACT. 1 INTRODUCTION The purpose of this study is to figure out ventilation performance and indoor environment in the high-rise office building with the cross ventilation system, which is used for natural ventilation and hybrid ventilation (HV) with using ventilation openings on each perimeter. Occupiers can select NV or AC (automatic select from HV, outside air cooling and mechanical ventilation). Additionally, exhaust assist fans promote air volume, when room temperature is high. In this study, ventilation performances of each modes, indoor air quality, thermal environment and comfort are studied with field measurements and questionnaires. In addition, as an operational improvement solution, we made NV assist charts, which shows its availability at each season and times in a day.

2 METHODS Ventilation performance are solved by decaying processes of tracer gas. The results of measurement of wind velocities at ventilation openings predict the correlation between internal pressure and amount of air flow. They prove the relations between outside wind velocity and air change rate of each modes. Air quality and thermal environment in real situation are solved by field measurements and questioners for office workers. NV assist chart is made in following. At first, to analyze heat load pattern of each occupier and outside air conditions. In second, assuming that NV is selected, to calculate room temperature and to check it for 90% acceptability range of the adaptive standard for natural ventilated buildings. Finally, for every 15 days, to put average agreement rates of each times in a day into a chart.

3 RESULTS First of all, the result of tracer gas method shows, in case of NV or HV without assist fan, the difference of air change rate between windward and leeward. By contrast, with assist fans, air change rate on leeward become well. Secondly, relationship between wind velocity and ventilation performance shows, when it is more than 2.0m/s, the mean wind velocity in Osaka, average air change rate is higher than 1.8h-1, the same level of the mechanical ventilation. Thirdly, the result of measurements in a real situation shows that air quality became well with using NV makes only few effect on pollen particles. In point of thermal sensation, on outflow side of cross ventilation, room temperature increased and some people claimed hot. Finally, NV assist charts express dynamic change of its availability by each seasons and times.

4 CONCLUSIONS Performance of cross ventilation is affected by wind velocity and direction. In this building, NV is designed to keep ventilation performance as well as mechanical ventilation with the mean velocity. Options like assist fan or HV help room environment improved. When there are some difference of thermal sensation between at inflow side, ventilation route and amenity are compatible to use HV at outflow side. NV assist chart is one of the operational improvement solution for a lot of styles to use office. It copes with changing of heat load and difference of occupiers and helps each occupier to select NV.

ABSTRACT. This paper describes a methodology for evaluating the effectiveness of various control strategies for the operation of window actuators to control the indoor climate, and their implementation in a full scale case study building. In this study, the effectiveness of a control strategy is considered in terms of the capability of the controller for maintaining the indoor thermal comfort in a prescribed variable range, and its effect on the minimisation of the operational energy consumption of the building, due to a lower thermal energy demand to be met by the heating and cooling system. A model of the case study building, the award winning Team UOW Solar Decathlon house, was developed and calibrated with measured data. A control strategy was simulated using the ESP-r tool as a building simulator and the Building Control Virtual Test Bed (BCVTB) as a flexible control strategy development platform. The measured states and disturbances of the system from ESP-r are sent to BCVTB at each simulation time step, to determine the windows opening percentage at the next time step. The controller and the house response were simulated in summer conditions in Sydney, and the results from the house with only mechanical cooling, when using natural ventilation only at daytime and when using natural ventilation also at night time have been compared. The base thermal demand of the building, with only mechanical cooling, was reduced by 28.9% using natural ventilation at daytime, and by 54.9% using natural ventilation also at night time.

ABSTRACT. To help member states meet the requirements of the Energy Performance of Buildings Directive recast (EPBD recast, 2010), the European Commission issued a mandate to European standardisation bodies to revise the first EPBD package standards published in 2007-2008 (M/480, 2010). This includes the revision of calculation standards to assess the energy performance of buildings.

The determination of airflow rates is a very important element to assess the energy performance of a building. With the revision process, EN 15242 (2007) that deals with this aspect will be replaced by EN 16798-7 and its accompanying technical report (16798-8). Flowrate through windows may be the toughest part of the calculation. The new pre-standard (prEN 16798- 7, 2014) submitted for public enquiry gives 4 methods to consider airflows through windows: a) A simplified method based on a multiplying factor of the required outdoor air flow rate; b) An explicit method based on a correlation for single-sided ventilation. It was based on work performed by de Gids, W. and Phaff, H. in 1982. It has been modified after public enquiry; c) An explicit method based on a correlation for cross-ventilation inspired from the French regulation RT 2012. It has also been modified after public enquiry; d) An implicit method using internal pressure as input.

Methods a) and b) were already in EN 15242 while methods c) and d) were new in prEN 16798-7.

This study compares window airing models defined in prEN 16798-7 and their modifications after public enquiry between themselves and with results obtained with CONTAM on 3 building geometries: a one-storey house; a 1 ½ - storey house without open staircase window; a 1 ½ - storey house with open staircase window. We have calculated the total outgoing air flow rate through the windows for various wind speeds (0 to 5 m/s), temperature differences (0 to 15 K), wind directions, and windows distributions for three internal resistance scenarios: no internal partitions, open doors and closed doors. As a preliminary step, we have implemented a modified wind speed model in prEN 16798-7 for relevant comparisons of iterative method with CONTAM.

The major findings are that 1) the single-sided direct methods (b) significantly underestimates the air flow rate compared to the implicit method (d) when there is cross-ventilation; 2) the cross-ventilation method (c) gives results in reasonably good agreement with the implicit method (d); 3) the windows distribution has a significant impact on results obtained with the cross-ventilation method (c) and with the implicit method (d); 4) the initial cross-ventilation method (c) tends to overestimate the air flow rate at high wind speeds and high temperature differences whereas it underestimates the air flow rates at low wind speeds and low temperature differences; 5) open doors do not significantly affect the air flow rate; 6) closed doors reduce the air flow rate in the range of 30% to 80% depending on the building geometry; 7) the revisions implemented after public enquiry for the cross-ventilation method reduce the risk to overestimate the air flowrate.

ABSTRACT. INTRODUCTION: A great energy saving potential lies within increased use of natural ventilation. As buildings become more well insulated and airtight according to the tightening of building regulations, the cooling demands increases and are for some buildings in colder climates not only found during summer and midseason periods but also during winter periods. The outdoor air during winter holds a great cooling potential if draft problems can be handled, and used in hybrid solutions, increased use of ventilative cooling also during winter periods, can be the solution that leads to large energy savings in buildings.

In situations where single-sided ventilation is needed, the calculation of airflows has earlier been done by expressions by De Gids & Phaff (1982), Warrens & Parkins (1985) and Larsen (2006), with different levels of details needed for the calculations. However, the aim for predicting ventilative cooling is to find the most suitable simple method that would in average perform well, while reducing the risk of overestimating air flows in individual cases with different temperature difference, wind direction/velocity and incidence angle.

A simplified design expression for single-sided ventilation is proposed for the revised standard EN 16798-7 (earlier EN 15242) and presented in this paper. Knowing that a simplified method for ventilative cooling may underestimate the airflows, this paper compares the simplified and detailed methods looking at pros and cons; so where we miss out and where we gain from using simplified calculation methods for future standards and regulations.

METHODS: An evaluation of existing single-sided ventilation calculation methods are made by parameter variations, comparison to full-scale measurements and wind-tunnel experiments. The evaluation is based on expressions by De Gids & Phaff, Warrens & Parkins and Larsen which are compared to a new simplified design expression proposed for the upcoming EN16798-7. The new simplified design expression is developed from a moderation of De Gids & Phaff to improve the calculation output according to the planned use in future standards and regulations.

RESULTS: The predicted air flow rate from the different design expressions are compared to measurements in wind tunnel and in an office building. The new proposed design expression for single-sided ventilation based on De Gids & Phaff shows results, limiting the overestimation of air flow rates at especially low driving pressures, while maintaining an acceptable correlation with measurements on average. A discussion on the “costs” in using a simplified method (no wind direction) versus a more detailed method (with wind direction) is made.

CONCLUSIONS: The comparison of the simplified and detailed design expressions reveals strengths and weaknesses based on the aim of the calculation. A guidance on when to use which level of details in the calculations are given. The new simplified design expression based on the moderated De Gids & Phaff formula showed results generally on the safe side and the authors consider the simplified calculation method well suited for the use in standards such as EN 16798-7 for ventilative cooling effects from single-sided nat.vent.

ABSTRACT. Recently, passive techniques have received a considerable attention in our modern buildings as a response to energy consumption, global warming and world ambition towards energy efficient buildings. Passive ventilation did not share a big ratio of interest due to several reasons such as the problem of natural ventilation fluctuations and the uncertainty of ambient weather conditions. It is much easier to use current mechanical ventilation systems especially in hospitals to achieve constant and acceptable results in terms of thermal comfort and indoor air quality. Although, not all hospital spaces need intensive control and could form a big ratio of hospital built area such as patients wards.

This study is a result of two previous researches regarding natural ventilation in vernacular hospitals and two modern ones in Jordan and Belgium. It tries to study the feasibility to integrate some of previous passive techniques in a typical patient ward in a Belgian hospital using CFD tool. Historical techniques will be simplified to integrate such techniques in current baseline model. The results of modified models will be compared with baseline model concerning ventilation performance.

The results will give a perspective regarding natural ventilation feasibility in patients’ wards and whether it is possible to enhance this renewable source to be integrated with current HVAC systems. In addition, it will spot the light on the threats that could appear regarding natural ventilation.

ABSTRACT. INTRODUCTION The stack effect occurs always when there exits temperature difference between indoor and outdoor air and climate wind pressure even increases its strength. This stack effect acts like a chimney: natural convection of air entering at the lower floors, flowing through the building and exiting from the upper floors. The vertical movement of the air within the building will occur in the shafts and staircases as well as any other openings that exist at the slab edge or in vertical piping sleeves at various locations that are not perfectly sealed. Uncontrolled air movement over the building envelope and further through the building increases draft risk and energy consumption. Over the neutral pressure level point, exfiltration happens and outflowing air could be condensate inside building envelope and increase the risk of mold grow. Also, high uncontrolled air movement could increase noise and the risk of spread of pollutions between apartments.

METHODS In this study, the effects of air tightness, ventilation performance, air leakage distributions, and outdoor environmental conditions on air pressure conditions in a high rise apartment building were simulated with a multi-zone simulation model using the IDA ICE simulation program. The simulation model was validated on the basis of field measurements, which allow this multi-zone model to be used for air pressure analyses in the cold Finnish climate. The analyzed solutions that prevent stack effect were: spatial arrangements, improved air tightness, control of ventilation and the optimized set points of HVAC systems.

RESULTS AND DISCUSSION Based on the carried out analysis, spatial arrangement and internal air tightness of shafts are playing the major role in the stack effect. Thus, in ideal condition staircases and lifts should be provided with own airtight anteroom. By using floor-specific pressure control of ventilation, it is possible to reduce stack effect. In addition by reducing air temperature of the shaft in the mid-season, it is possible reduce the stack effect. Also, it is important to preclude unnecessary window and door opening.

CONCLUSIONS The uncontrolled air movement through a building envelope leads to problems related to hygrothermal performance, health, energy consumption, performance of the ventilation systems, thermal comfort and noise. The stack effect is possible prevent with airtight spatial arrangement, over-pressurized and cooled stacks and floor-level pressure control.

ABSTRACT. INTRODUCTION To improve the thermal environment in houses, many people prefer using natural cross-ventilation to using an air-conditioner. Furthermore, utilization of cross-ventilation is an important to reduce energy usage in residential buildings. However, utilization of cross-ventilation by using two wall windows is difficult due to the influence of adjacent buildings in crowded city block. As one method of solving this problem, we focused on the ventilation tower (The planar shape of the ventilation tower is a square and the ventilation tower has four windows). It is important to study the best shape of ventilation-tower because it is assumed that pressure affecting ventilation-tower varies greatly by the difference of shape of ventilation-tower. Therefore, the purpose of this study is to evaluate the cross-ventilation performance with various shape and height of ventilation tower.

METHODS We did wind tunnel experiment by using 1:40 scale residential model with the condition in which there are no neighboring buildings. First, we prepared four types of ventilation-tower whose height is 0.25m, 0.5m, 0.75m, 1m (actual size) and surveyed the wind pressure coefficients and the quantity of cross-ventilation. We also surveyed a change of the wind pressure coefficients from the relationship between opening and closing of four ventilation tower windows and approach flow. In addition, we made the ventilation tower models whose shape is different (square, circle, rectangle) and grasped the quantity of cross-ventilation by Computational Fluid Dynamics (CFD) analysis.

RESULTS and DISCUSSION From the measurement results in a wind tunnel, it was found that ventilation-tower over 0.5m high shows nearly same wind pressure coefficients and quantity of cross-ventilation even though height of ventilation-tower is varied. This is because an approach flow reach the window of the ventilation-tower whose height is over 0.5m, without the influence of the separated flow occurred in the roof surface, and velocity of approach flow reached the window of the ventilation-tower did not change. We also found that the ventilation tower produces large negative pressure by closing a window of upwind. This is because an approach flow collide with the closed window of the ventilation tower and the separated flow occur. In addition, by CFD analysis, we found that the ventilation tower of square can get the stable quantity of cross-ventilation regardless of the wind direction.

CONCLUSIONS The cross-ventilation performance of ventilation tower which is over 0.5m high is hardly any difference. In addition, the ventilation tower produces large negative pressure by closing a window of upwind and we can expect to get the large quantity of cross-ventilation. In terms of planar shape, the ventilation tower of square can get the stable quantity of cross-ventilation regardless of the wind direction and we can get twice as large quantity of cross-ventilation as quantity of cross-ventilation by using two wall windows.

ABSTRACT. In educational buildings, efficient ventilation is vital for better indoor air quality and less contaminant level. High level of carbon dioxide concentration causes to drop in concentration and learning capacities of students in addition to headache, dizziness and rapid spreading of infections. In order to provide high indoor air quality; indoor temperature, carbon dioxide level, air humidity and air flow rate should be in the comfortable zone defined by standards. Natural ventilation is preferable solution since it provides improved indoor air quality with reduced energy consumption. The present study investigates the applicability of natural ventilation in the Middle East Technical University Library Reserve Section in Ankara, Turkey for desired indoor air quality defined by ASHRAE air quality standards. Temperature, carbon dioxide concentration and relative humidity data are collected during experimentation period. In the analyses, single zone model is considered. Computational fluid dynamics (CFD) analysis will also be performed for the comparison of results. Comfortable air flow rate is examined using CFD analysis. Energy saving for winter times is calculated. According to the results, solutions are provided for a better indoor air quality and application of natural ventilation. Experimental and numerical results clarify that natural ventilation can be used in winter times in order to reduce the carbon dioxide concentration inside the zone. Mathematical results show that there is an energy saving about 10 percent with usage of natural ventilation. CFD results will be compared with these results.

ABSTRACT. Natural ventilation, as a key passive design strategy, plays a central role in thermal comfort and energy efficiency in tropical climate. High performance of natural ventilation in residential buildings could replace and/or reduce the use of air conditioning system and contribute to energy efficiency, thermal comfort, indoor environmental quality (IEQ), and reduction of household expenses. Based on the advancement of Computational Fluid Dynamic (CFD) technologies, the passive design alternatives of natural ventilation could be further rapidly validated in the building design stage. In this paper, we made an effort to evaluate the natural ventilation performance in design phase of one new public residential housing project in Singapore. This project comprises ten blocks (totaling 1,057 units) with the height between six to seventeen stories. In this case study, an advanced iterative CFD approach was conducted to examine and optimize the air flow conditions of the design alternatives, whereby a number of parameters were considered in both outdoor and indoor environments. Such parameters include pressure, wind speed/air flow, wind flow patterns, regional weather data, adjacent building (diameter: 1,670 m). In the iterative CFD process, firstly outdoor CFD simulations were carried out to examine the pressure values on all the openings. Then the pressure differences in all the units were analyzed in order to select the typical units, followed by the indoor CFD simulations. Finally the thermal comfort within units were analyzed and analogized to the whole project. This study contributes to the optimization and validation of natural ventilation performance of design alternatives in design phase of residential buildings. The results will be expected to serve as a solid basis of CFD applications to shorten the validation process in large scale of residential building design. In the future, comparison of various methodologies of CFD simulations in residential building design will be further studied.

ABSTRACT. This study aims to test how mixing ventilation combined with a hydronic radiant floor system performs removing airborne exhaled contaminants using two different air renovation rates. The two selected renovation rates are 2 ACH and 7.5 ACH. Temperature and velocity probes are used to evaluate temperature and velocity profiles in the room. A tracer gas (CO2) is used to measure the risk of cross infection between two breathing thermal manikins. One of the manikins (P) represents a lying person over a horizontal surface and its breathing represents the only source of contaminants into the chamber. The other one (HW) represents a standing person near P. The concentration of exhaled contaminants reaching its breathing zone is studied. Temperature and air velocity profiles show that a nearly completely air stability situation is reached at the occupied zone. This stability is influenced by the air renovation rate performed. Tracer gas measurement results show a similar distribution of exhaled contaminants but with some discrepancies for both tests conducted. A higher tracer gas concentration reaches the nearby zone of HW manikin when the air renovation rate is increased from 2 to 7.5 ACH. This can lead to a higher cross infection rate. The obtained results suggest that that a higher ventilation rate not necessary leads to a decrease of the airborne cross infection risk for the occupants in an enclosed area.

ABSTRACT. The main purpose of ventilation systems is to satisfy the need of occupants in terms of thermal comfort and air quality. In the case of mixing ventilation, which is based on the use of jets initiated from one or multiple diffusers placed in the room, the diffusers should distribute the fresh air and energy for heating or cooling, in the entire occupied zone. Hence, the design of the diffusers must aim, beyond aesthetic aspect, the ability to well mix the jet with the ambient air. Enhancement of jet mixing with the ambient air by means of lobes inserted into a diffuser, has been recently proposed as a promising and low-cost solution for improving the performance of HVAC systems. In this paper, an experimental investigation is made on jet characteristics and thermal comfort generated in a full scale model room by a conventional circular ceiling diffuser and its performance is compared with an innovative lobed diffuser having similar geometry, under identical inlet conditions. A simplified manikin simulates the presence of a human body in the test room. Airflow pattern from the diffuser and its interaction with the heated manikin were analyzed with whole-field PIV technique. Thermal comfort was explored and analyzed based on traditional point measuring probes and the standard ISO 7730. It is revealed that the thermal comfort was significantly improved using the lobed circular ceiling diffuser compared to the conventional one.

ABSTRACT. Introduction: High energy consumption in the building sector has led to a great need for energy saving and energy efficient solutions for buildings. Reducing the energy needs in high-performance energy buildings encourage simplification of the space heating system, e.g. with a wood stove or a radiator. A reduced space heating system leads to temperature differences and lower temperatures inside rooms which are not directly heated. In addition, depending on the geometry of the building, there is a risk that the room equipped with a heating device may be overheated while the rest of the building may be heated too little. Another problem may be the draught risk in the lower part of the room with the heater as warm air moves up due to buoyancy force. The question arises, how can one heat emission system ensure thermal comfort in the entire building? This still remains unclear due to lack of understanding of some fundamental aspects, including heat transfer within or between different zones and temperature stratification inside zones. In order to achieve a proper indoor thermal environment, the heat transfer between the rooms should be well understood and even enhanced. The objective of this study is thus to examine the airflow distribution patterns through a doorway with and without air curtain. Methods: Laboratory measurements have been conducted in a climate chamber equipped with a heat emission system. The chamber consisted of two zones – heated and not heated. Air temperature measurements were carried out to determine the effect of air curtain operation on the airflow distribution inside and between the two zones together with temperature differences. Measurement results were obtained for various airflow distributions generated by the slot diffuser located above the doorway between the two zones. Different discharge velocities from the slot diffuser were used during the experiments. Results and discussion: The experimental results show that the air distributed by the slot diffuser provides better mixing inside both zones, minimizing the vertical temperature stratification inside zones. The stratification inside the cold zone is 1.8°C for a discharge velocity of 3.8 m/s and 1°C for a discharge velocity of 8.5 m/s. The temperature stratification inside the warm zone is 5.2°C for a discharge velocity of 3.8 m/s and 1.8°C for a discharge velocity of 8.5 m/s. Another effect which comes with increasing velocity supplied with the air curtain system is that it is possible to obtain higher temperatures at lower levels inside the cold zone. Moreover, supplying the warm air through the air curtain system decreases the period of time needed to achieve a satisfactory thermal environment inside both zones. Conclusions: The discharge velocity of the downward plane jet from the slot diffuser in an air curtain system directly affects the performance of the airflow and heat distribution inside and between zones. One of the advantages of distributing air with the air curtain system is that the warm air inside zones is well mixed and quicker distributed to the lower part of the zones, reducing the vertical temperature stratification. As a result, the potential risk of draught is significantly reduced.

ABSTRACT. INTRODUCTION: Active chilled beams are used to simultaneously ventilate and cool or heat indoor spaces. The characteristic feature of these devices is the entrainment of room air due to turbulent mixing at the jet edges of multiple small, high velocity primary air jets inside the device. Usually, air is entrained from a defined direction perpendicular to the primary air jet axis through a defined opening causing the jets to deform and to deflect. Mixing of the primary and the entrained air takes place in a duct further downstream before the mixed air exits the active chilled beam into the room. The thermal power of the active chilled beam depends on the entrainment ratio, meaning the ratio between the volumetric flow rate of the entrained secondary air and the supplied primary air. Main influences on the entrainment ratio are the beam’s internal geometry or additional flow losses, as due to a heat exchanger, for example. In this paper, impacts of three factors influencing the entrainment ratio are investigated experimentally. Firstly, the area of the rectangular entrainment opening is varied by altering the opening length in the jet flow direction. Secondly, the duct geometry is varied with respect to the streamwise cross-section by altering the bottom wall to form a diffusor outlet. Thirdly, the pressure drop in the entrainment air inlet is varied to account for different heat exchanger flow resistances.

METHODS: Measurements were conducted using an experimental setup containing an optically accessible, generic geometry of an active chilled beam with a single nozzle. To determine the instantaneous entrainment rate primary air flow rate was set using a mass flow controller. Secondary air flow rate was controlled and determined using the differential pressure method. Flow fields were measured in the symmetry plane using 2D2C particle image velocimetry (PIV) under isothermal conditions.

RESULTS AND DISCUSSION: Entrainment ratio increases non-linear with increasing entrainment opening area. Maximum entrainment ratios are found for small diffusor outlet angles. Entrainment ratio decreases linearly using small entrainment opening areas and non-linearly using larger entrainment opening areas for higher diffusor angles whereupon a different wall attachment behavior of the jet can be observed. For given entrainment air flow resistances entrainment rates increase with the nozzle Reynolds number.

CONCLUSIONS: It can be concluded that the entrainment behavior of a single jet in a generic geometry of an active chilled beam can be optimized by geometrical values like the entrainment opening area and the diffusor angle of the supply duct. However, optimal geometry values are dependent on factors limiting the upstream entrainment air supply like the pressure resistance of a heat exchanger, for example. Entrainment ratio and flow pattern were evaluated in order to gain insight into the relevant factors influencing the induction behavior. Based on the measurement results the suitability of different numerical simulation models can be evaluated. Ultimately, valid computational models are needed for the development of geometries with improved performance.

ABSTRACT. One of the primary way to save energy, infrared sensor is being applied in residential air conditions. This sensor can detect the human position in the room by infrared radiation that emanates from the body. And control the air flow direction to the occupants. This effect is known to keep the lower ambient temperature about 2~3℃ near the body than other area in the room so, this control can get more cooling effect and less energy consumption. This energy save controlling mode is widely applied on products but, there is no enough research of direct cooling effect on human body by residential air conditioner. This research is focus on the evaluating thermal environments of residential air conditioner’s spot cooling effect based on equivalent temperature. Equivalent temperature is expressed by one temperature value so, very easy to recognize effect of environments without many factors. Before evaluate the thermal environment by equivalent temperature using a thermal manikin simulation, verify the simulation model with previous research data of thermal manikin test. Thermal manikin is separated by 16 segments to see each part of the equivalent temperature by heat transfer. The numerical simulation at 24.0℃ standard environment is calculated by 4.95𝑊/𝑚2∙𝐾 radiative coefficient and 3.12𝑊/𝑚2∙𝐾 convective coefficient. To confirm the air speed effect on heat transfer on body surface, calculate the different air speed of residential air conditioner’s outlet openings (the maximum available air flow speed on outlet is 5𝑚/𝑠). And variable outlet temperatures are simulated to find out the correlation between air flow temperature of air conditioner and equivalent temperature of body. The result shows that the calculated equivalent temperature with 0.5𝑚/𝑠 air speed around the manikin is twice effective than simply expected ambient temperature drop of 2~3℃.

ABSTRACT. In recent years, the introduction of air conditioning for spectators’ seats and grandstands in stadia has increased with the development of technology. However, much of this has focused on indoor stadia, and almost no cases have been seen in outdoor stadia. In contrast to an indoor stadium, the environment in an outdoor stadium is always changing according to the effects of various disturbances; therefore, it is very difficult to air-condition outdoor stadium seats. Consequently, we focused our study and development on outdoor stadium chairs as a way to introduce air conditioning into outdoor stadium seats. This paper provides a rough outline of a developed air outlet called “variable Coanda nozzle” and evaluates the fundamental performance in seats where in the nozzle was installed. Development proceeded from the premise of ordinances in Tokyo, Japan. The minimum stepping floor size in a stadium is 750 mm, as established by a fire prevention ordinance. Therefore, it is difficult to secure sufficient space to install an air outlet. For riser audience seats in a stadium, the existing technology is riser air conditioning. However, cold air remains under spectators’ feet because the existing system is unable to blow cold air to the upper body, and only the lower body is cooled. Therefore as the place where air outlet is installed by the size and arrangement which conforms to the ordinance, the system wherein the air supply function is added to a tergum studied. The inner wing is the streamlined shape, the air current that has passed through inside of the tergum is blown through the "variable Coanda nozzle" upward on the upper part of tergum. This is possible due to the Coanda effect, which occurs because of the difference between the internal and external pressures of a tergum. Additionally, the air current is blown from an opening in the upper part of the "variable Coanda nozzle" by turning the nozzle, with the air current being curved by the difference between the internal and external pressures of the tergum. Finally, the air current emerges at the same angle on the left and right sides of the nozzle, and interferes in the direction of the seated person. Basic performance evaluation experiments were conducted at the Kogakuin Twin Chambers at Kogakuin University in Hachioji, Tokyo. Local wind velocity and surface skin temperature measurements were performed using a thermal mannequin. Basic performance experiments substantiated the extent to which a comfortable summer environment could be achieved in a Tokyo stadium by blowing an air current onto a spectator’s skin surface using a personal variable Coanda nozzle.

ABSTRACT. In many applications, such as in cleanrooms and in operating rooms, free jets are used to form local areas of high cleanliness. The jets are issued from rectangular orifices that contain terminal filters and are therefore assumed to be “clean”, while the surrounding air is potentially contaminated.

Within the so called constant velocity core, the air has not mixed with surrounding air and the initial velocity is maintained. Surrounding air is entrained around this core, forming a contaminated, turbu-lent mixing layer. The core diameter shrinks approximately linearly with increasing distance from the opening. Eventually the core disappears at a certain distance from the opening; this distance is re-ferred to as the “jet length”.

Manufactured goods or persons that are to be protected from contamination must be placed within the core of the jet to avoid contact with contaminated air. To enlarge the protected area provided by a jet, the jet length has to be maximized in order to maximize the diameter at a specific distance.

In this paper, a method called “Design of Experiments” (DoE) is used to determine the factors that influence the jet length the most. A vertical, isothermal jet in a still environment is examined for this purpose. The following three parameters are considered: intensity of turbulence, initial velocity, and length of a solid curtain mounted on each edge of the outlet. The experiments are conducted using two extreme settings for each factor. Using DoE, not only the effect of each factor is identified, but also any interdependencies between factors.

Subsequently, the investigation focuses on these important parameters. The results show, that the jet length may be extended using simple procedures. The results also may help design outlets that pro-vide an improved jet characteristic for a higher level of contamination control.

ABSTRACT. The necessity to drastically reduce the space-heating (SH) needs of residential buildings in Europe has prompted the emergence of building concepts based on a super-insulated building envelope, such as the passive house (PH) standard. While the construction of passive envelopes is more challenging, these envelopes also offer opportunities. Given the level of insulation and the use of high-performance windows, the SH distribution system can be simplified because it is theoretically not necessary anymore to place a heat emitter in each room, or in front of windows. A well-known simplified approach is the so-called centralized air heating but one could also consider a wood stove or a limited number of low-temperature radiators. In practice, there is lack of fundamental knowledge to support the simplification of the SH distribution system in PH. In fact, the limitation of the heat emitters’ number to a couple of rooms inevitably leads to temperature differences with the other “non-heated” rooms. In order to reach an acceptable thermal comfort in the entire building, the heat transfer between rooms should be promoted. Different studies have however shown that the opening of internal doors is an efficient way to homogenize temperature in PH. In fact, a large bidirectional flow will occur through doorways with flow rates that are significantly higher than the nominal hygienic airflow rates provided by the balanced mechanical ventilation. The present study aims at investigating how this convective heat exchange can be properly predicted. The overall objective is to propose a best practice to design simplified SH distribution systems in PH, especially for cold climates.

The airflows assessment using building performance simulation (BPS) most often relies on a ventilation-network model (e.g. the COMIS software). Airflows through doors are then essentially modeled using a large opening approximation which introduces the concept of discharge coefficient, Cd, to tune the model to specific flow physics. (1) Hypotheses behind this model (i.e. “bulk-flow”, isothermal rooms) are unfortunately crude so that it could not be directly applied to the present application: the heat emitter can have a relatively higher surface temperature than the room. (2) Furthermore, the temperature field within the doorway may differ significantly from this theory. Consequently, the convective heat exchange is different than expected. These phenomena have not been reported extensively in the scientific literature.

Consequently, the present contribution will report on airflows in doorways using field and laboratory measurements. Furthermore, these measurements will be compared with theoretical calculation and usual simulations approaches (i.e. using a ventilation network model and CFD). The prediction of the temperature field will be particularly discussed as it is of major importance for the convective heat transfer and as it appeared poorly evaluated using usual modeling approaches. Measurements indeed showed that the temperature field is well smoother than predicted, a phenomenon which can be caused by the flow asymmetry and/or interfacial mixing.

ABSTRACT. Air velocity and turbulence intensity are very important features from the point of view of draught comfort. There are several slot-ventilated rooms, e.g. classrooms, offices, swimming pools, restaurants, etc. Several researchers have investigated room airflow characteristics in ventilated spaces (e. g. also in slot-ventilated rooms). However, most of the investigations had not considered the effect of some important inlet parameters on room airflow. These parameters are inlet Reynolds-number, air diffuser’s aspect ratio (AR), and diffuser’s offset ratio (OR) related to the wall. In this paper a slot-ventilated room is investigated on a full-scale model using measurement method. During the measurements the three most important inlet parameters were changed: inlet Reynolds-number, air diffuser’s aspect ratio and offset ratio. All of the measurements were conducted in isothermal and steady-state conditions using omni-directional probes. The measurement points were fixed at the relevant points of the occupied zone in four heights: ankle level, knee level and head level of sitting and standing person. The measured data were evaluated with statistical methods and tests, including measurement uncertainty calculation. Draught Rate (DR) number features the draught comfort was also investigated in the room. Results can help designing draught comfort in ventilated spaces.

ABSTRACT. Nowadays, in newly built housings, energy losses due to the ventilation can represent up to 50 % of the total building energy consumption. As a result, heat recovery ventilation units are widely used in order to save primary energy and different control strategies for ventilation systems are investigated. For instance, demand control ventilation sounds like a promising solution to decrease the energy impact of the ventilation system in the residential sector. An accurate building model integrating the influence of ventilation (so called thermo-aeraulic building model) is necessary in order to investigate the control and the impact of the ventilation system on a yearly basis.

The aim of the present paper consists in a description of a combined multi-zone airflow network model and thermal building model implemented in the Modelica language. The thermal model is a simplified dynamic model using equivalent thermal resistance and capacity. The airflow network is based on the traditional electrical circuit analogy. The model can be used for ventilation systems design, infiltration rate calculation, inside air quality calculation, energy consumption calculation, etc.

The first part of the paper details the multi-zone thermal building model. The results obtained from the model are compared to experimental in situ results collected in the typical single family house test facilities. Those experimental results have been obtained in the frame of the IEA-EBC Annex 58.

The second part of the paper introduces the multi-zone airflow network building model. Obtained model results are compared with the results provided by a typical multizone airflow analysis software, for a simple three zones test case.

The third part of the paper describes the coupling between both thermal and airflow models. The different numerical problems encountered are described and solutions are discussed.

The last section presents an application example. A typical Belgian apartment is modeled and different ventilation systems are considered: a dual-flow mechanical ventilation system and a simple exhaust mechanical ventilation system. The different configurations are compared in terms of primary energy consumption and indoor air quality.

ABSTRACT. In terms of modelling and controlling indoor air properties like temperature or relative humidity in detail the spatial distribution has to be taken into account. The common approach to do that is the use of Computational Fluid Dynamics (CFD). Although this is a very powerful tool, the method suffers from high complexity and high computational costs. Nevertheless, CFD Simulations are commonly accepted for planning tasks. From a control theoretical point of view the mentioned points depict a great disadvantage and the need of model reduction arises. In this paper we present a fuzzy approach to approximate the spatially and temporally distributed heat and moisture transfer to gain a reduced model that can easily be used for control tasks of HVAC Systems. Furthermore an algorithm for system identification is presented, to derive an accurate system model directly from measured data which can be used for control tasks of indoor heat and moisture transfer. Given the governing equations of a general flow problem, which are also used for CFD-Simulations, a highly nonlinear system is obtained. For that reason we suggest to use a Takagi-Sugeno Fuzzy approach to take care of those nonlinearities of the system. At first, the governing partial differential equations are discretized by finite-difference methods. This leads to a set of nonlinear ordinary difference equations, for which several linear submodels can be derived in different operating points. Those linear submodels are aggregated to an overall model by using the fuzzy theory and defining a weighted validity range. In that way, the nonlinear system can be transformed to a weighted sum of linear systems, which is called a Takagi-Sugeno Fuzzy Model. The big advantage of this approach is that the linear control theory can be applied to each submodel and the nonlinearities can be neglected. Another great benefit is the simplification to learn models from data, by using linear system identification techniques like least squares estimation or recursive least squares estimation for online application. In this paper we will first of all derive the proposed approach and introduce an algorithm that develops a spatially distributed Takagi-Sugeno Fuzzy Model from real measured data in a historical building. We will also compare the results to commonly used CFD-Simulations and give an accuracy estimation of the proposed approach. The generated model can then be used to develop a controller for HVAC Systems, which takes the spatially distributed property into account, to gain better control results. The development of such a controller will be briefly explained and is part of future works.

ABSTRACT. The room air stratification in which a zone is divided into two regions which are the occupied region near the floor and the non-occupied region near the ceiling is the core principle of energy performance in UFAD (Underfloor Air Distribution) system. Through the principle, air conditioning is only needed in the occupied region in cooling mode. Therefore, the building is able to realize energy saving. However, the thermal decay, defined as the supply air temperature rise due to the heat gain into supply plenum, is able to decrease the energy saving. Therefore, in this study, the cooling load and energy consumption of UFAD system were analyzed in an office building. Especially, fundamental impacts of thermal decay on energy performance degradation were analyzed. As a result, UFAD system consumed relative higher energy due to the thermal decay, despite the lower cooling load according to the stratification, and the thermal decay lead to the increase of the supply air flow rate and the decrease of density difference between zone air and supply air. Finally the stratification disappearance caused by those factors decrease the energy performance of UFAD system. Those indicate that thermal decay needs to be resolved for the optimized performance of UFAD system.

ABSTRACT. Due to the overpopulation in urban cities in Korea, high-rise residential building became Korean’s most popular type of residence. High-rise residential building increase stack effect that comes from air temperature and density difference between indoor and outdoor air, and it makes many problems such as elevator breakdown, difficulty to open the door, noise, draught and others. Many researches were reported for these problems and proposed the countermeasures to reduce the stack effect related problems.

When the air flows in buildings driven by stack effect, heat, vapor and pollutants are moved together. This phenomenon is related to the residents’ health and quality of life which is mainly issued in these days. In this study, the characteristics of air flow, heat, vapor and pollutant’s movement in high-rise building were analyzed by long-term measurement in winter. The result of long-term measurement as follows;

1. The air flows from exterior wall into indoors at the lower part of the building and it ascended through elevator hall and vertical shaft. In upper floor, the air flows from elevator hall into indoors. Because of this kind of airflows in analyzed building, a lot of vapor and pollutants was detected in upper floors compared to the lower floors. The highest heat, vapor and CO2 concentration level were measured at the middle floors of the analyzed building.

2. When the temperature difference between indoor and outdoor air was small, the airflow caused by stack effect was decreased, and the concentration of vapor and pollutants were increased.

The result of this study showed that the heat, vapor and pollutants are moved accompanied with the airflow in high-rise residential buildings.

ABSTRACT. Building designers use quantitative models to foresee the expected quality of the indoor climate when designing buildings. Most famous is the concept of Predicted Mean Vote (PMV) which is widely accepted and used for design goals in building design projects. However, a number of experiments show that there seems to be a deviation between this heat balance-based “theoretical” thermal comfort expressed by PMV and the actual user perception of thermal comfort in real buildings. Reasons for this deviation are by some ascribed to be the occupant expectations to the indoor climate and the possibilities of occupants to adapt themselves or their environment to maintain thermal comfort. This is acknowledged in the so-called adaptive comfort models and in the expanded PMV model called PMVe. However, more studies are needed to understand how expectation and other factors may affect the notion of thermal comfort. One challenge of research in this area is to gather data of sufficient quantity and quality. This paper therefore reports on the development of a desktop polling station (DPS) for fast and reliable collection of vast amounts subjective and objective data simultaneously in a fast and reliable manner.

The DPS is a small box with an interface where building occupants can be asked for their subjective assessment of the indoor climate while sensors continuously are logging objective measures like air temperature, relative humidity, CO2 concentration, and illuminance level. The desktop polling station was designed and built to be located at each participant’s workstation making the interaction easier. This allows the occupants to participate in studies without them having to change location, time schedule or environment. Interactions with the DPS are encouraged trough prompts for regular subjective feedback by blinking diodes in the buttons.

A pilot field study was conducted on the lower floor (2nd) of a 5-story open plan air-conditioned office in Aarhus, Denmark. Data was collected at the workspaces of nine participants with a distribution of gender at 40% female and 60% male. All participants had similar work task that involved computer work for the majority of their work hours. A total of 371 subjective assessments of the indoor environment were collected on the course of 10 workdays. In average each DPS collected 4.7 participant responses per day but the most active participants had 8-12 assessments per day. Processing the data, a difference between PMV and Actual Vote was observed. The difference could be explained by a relationship between the derived expectation factor and air indoor temperature and relation between the expectation factor and running mean outdoor temperature. The scale of the pilot study is not sufficient to make any sound conclusions for further developments of indoor climate models. However, the pilot study has illustrated that the DPS technology has the potential to collect vast amount of data in a short time – data which is valuable for various purposes in indoor climate research.

ABSTRACT. Building constructors usually see themselves on the supply side of the housing industry. However if the idea of sustainable buildings is to spread, the demands put forth by users need to be given serious attention. Thus, switching from the supply side (of house builders) to the demand side (of users) we ask: What is it that people actually want in housing? If sustainable housing is to proliferate, we must take the wellbeing of users into account. They will not buy and move into houses they do not find worth living in.

Looking at the demand side, we must relate the wellbeing of users to the physical properties of buildings, sustainable buildings in particular. In quantitative terms what this means is establishing functional relationships between wellbeing scores and physical building parameters. This is basically what classical psychophysics is doing: mental sensations are studied as causally determined by physical objects and object intensities.

But what is housing wellbeing? There are four propositions advanced in this paper:

1. Housing wellbeing is different from the feeling of comfort people have. 2. Housing wellbeing is a descriptive, not a normative concept. 3. Housing wellbeing originates from individuals, but must be conceptualized as an attribute of buildings. 4. Housing wellbeing can be measured representing a multi-dimensional construct.

These propositions are elaborate on in turn and are then put to work in assessing housing wellbeing empirically, first in the VELUX Model Home 2020 experiment (2011-2014) and subsequently in a large-scale population survey of 14 core European countries, the Healthy Homes Barometer (2016), to validate results. We thus work our way from experiment to testing the generalizability of outcomes Europe-wide.

In the Model Home 2020 experiment, several methods were used for exploring wellbeing with the test family: initial group discussions with family members, self reports using diary methods and digital logbooks. In addition, approximately every four weeks respondents completed an online questionnaire including both standardized and open-ended questions about the various dimensions of their wellbeing. About every six weeks, in-depth interviews were conducted in the form of video calls. Finally, extensive structured face-to-face interviews were carried out in the model home itself at the end of the yearly seasons. These different procedures led to the accumulation of a very detailed recording of the family’s wellbeing in the house.

Subsequently, this material was analyzed with factor analytic methods in order to uncover the underlying structure of housing wellbeing that was then put to several empirical tests with subjects from outside the model home. As a last step, the calibrated measurement instrument, the Housing Wellbeing Inventory (HWI), was incorporated into the Healthy Homes Barometer (with N = 14.000 respondents) in order to develop a standard for the measurement of subjective housing quality in sustainable buildings.

ABSTRACT. Different recent studies [1][2] have shown the ventilation of modern Dutch houses, and especially the ventilation of the bedrooms, to often be insufficient. While some is available on the effect of ventilation on persons with sleep-related breathing disorders [3], little is known of the effect of (insufficient) bedroom ventilation on the (perceived) sleep quality of healthy people. The aim of this study was to determine the effect of bedroom ventilation on perceived sleep quality. For this purpose, data from a previous field study [1], which was aimed on the performance of mechanical ventilation systems and its effect on the self-reported health and perceived indoor environmental quality, was reanalyzed. In this previous study, among other things, the air supply and air exhaust rates of 299 Dutch houses, built between between June 2006 and January 2008, were measured. Of the 299 houses 150 houses were equipped with balanced mechanical supply and exhaust systems with heat recovery (MVHR) and 149 houses were equipped with mechanical exhaust ventilation systems (MEV) coupled with natural supply through ventilation grilles. A questionnaire was used to, among other aspects, determine the usage of the ventilation systems by inhabitants and their perceived sleep quality. Questions regarding the perceived sleep quality were based on a shortened version of the Groningen Sleep Quality Scale (GSK) [4][5]. Statistical analyses (p < 0,05) were conducted to determine associations between the amount of ventilation and the perceived sleep quality, corrected for the type of ventilation system. The following significant correlations were found for houses with MVHR systems: - Inhabitants of dwellings with a higher fresh air supply in the master bedroom (ventilation system on nighttime setting) reported lower sleep disturbance (GSK) scores. - Inhabitants of dwellings with a higher fresh air supply capacity in the master bedroom (ventilation system on highest setting) reported to fall asleep more easily. - Among inhabitants of dwellings with a higher total air exhaust capacity (ventilation system on highest setting) were less persons who reported to experience short sleep durations.

The following significant correlations were found for houses with MEV systems: - Among inhabitants of dwellings with ventilation grills with a higher air supply capacity in all bedrooms were less persons who reported to experience a lot of tossing and turning at night; - In habitants of dwellings with a higher total air exhaust rate (ventilation system on the nighttime setting) reported less awakenings at night and less nights in which they slept poorly; The abovementioned results suggest that increasing bedroom ventilation can improve perceived sleep quality. Perceived sleep quality might also improve next day performance.

ABSTRACT. The present study is based on the 6 month long post occupancy evaluation occupants’ perception of indoor air quality of recently renovated 23 apartments in Copenhagen. The apartments are equipped with mechanical ventilation systems. The apartments can be categorised in four, according to the design of ventilation systems. All the ventilation units are reequipped with parallel plate cross flow heat exchangers. The analysis in present article is based on occupants’ perception of the measured indoor quality and energy consumptions. Among four different types of ventilation system, one is traditional decentralized ventilation system which works only on two speeds i.e. high flowrates when kitchen exhaust is on otherwise lower flow rates. There are no sensors in the apartments that have this kind this kind of ventilation units. Second type of ventilation systems are the decentralized ventilation system with motion in hallways and humidity sensors in all the rooms along with the kitchen hood sensor. Third type of ventilation systems is a centralized ventilation system with the motion sensors in hallways and toilets, humidity sensors in each room along with kitchen exhaust hood sensor. The fourth ventilation system is a centralized ventilation system with only kitchen exhaust hood sensor. Second, third and fourth types of ventilation systems are also equipped with a recently designed drop type dampers that has a very low pressure drop. The dominant part of the study is based on the occupants’ perception on the performance of ventilation systems.

ABSTRACT. The two schools Langebjerg and Endrup are located north of Copenhagen in Denmark and renovated recently. The renovation follows Active House principles. The purpose of the renovation was to improve the indoor air quality (benchmarked by perceived freshness and CO2 levels) daylight levels and daylight distribution. To achieve the renovation targets, additional windows were installed and demand-controlled (based on CO2) natural was applied. Mechanical ventilation was used in one of the schools for basic ventilation.

Simulations of Daylight Factor, Useful Daylight Illuminance and Daylight Autonomy were used to optimise use of windows. Simulations of air change rates and CO2 levels were used to optimise the control of window openings.

Temperatures, sound levels and CO2 levels have been logged with sub-hourly values since January 2015 using Netatmo sensor stations. Use of electrical light has been recorded in the same period in one of the schools by installing HOBO Data Loggers in the light fixtures. Unrenovated class rooms have also been evaluated.

The recorded data on indoor climate is presented and evaluated according to the Active House Specification. Renovated and unrenovated class rooms are compared.

ABSTRACT. Nowadays an importance of indoor air quality is highlighted by numerous researches. There are strong dependence between CO2 concentration and human health and office workers performance. This study provides research on sportsmen performance under different indoor air parameters. During the study the IAQ parameters were measured in three different sport halls and special questionnaires were distributed between taekwondo sportsmen. Age of sportsmen 10 – 15 years. In order to evaluate performance of taekwondo fighters the total number of received scores by the same fighters in different sport halls were compared. Results have shown that in sport hall with higher CO2 concentration number of received scores were much smaller in comparison to halls with CO2 concentration at 1000ppm.

ABSTRACT. Introduction: With buildings being responsible for about 40% of the energy consumption of the world (UNEP 2009), there is a need for energy-reducing measures in the building sector. In our modern society, people spend as much as 90% of their time indoors; at home, at school or in their workspace. It is therefore important that the indoor climate should not be harmful for human health. The objective of this study is to investigate the indoor climate in an energy efficient building with balanced mechanical ventilation in Norway.

Methods: Field measurements during the month of November in an energy efficient office building in Trondheim have been performed. Parameters such as temperature, air velocity, relative humidity, PM and CO2 concentration were measured and analysed. Two single offices, two open offices and one meeting room were investigated in this survey. Selected locations in each room were measured. It must be noted that the study is not representative for the whole building as only five rooms in the third floor were evaluated.

Results and discussion: The results showed that the thermal environment was within satisfactory limits. The thermal environmental of measured rooms was within categories of A and B according to the international standard ISO 7730 (ISO 7730 2005). The maximum PPD was 7% and maximum PMV was -0.28. Indoor CO2 concentrations were below the recommended maximum limit and the highest measured concentration, 650 ppm, was detected in a single office. The relative humidity was found to be slightly low and varied between 20% and 25%. The PM2.5 and PM10 values in the breathing zone were below the recommended maximum limits according to the Norwegian Institute of Public Health and the World Health Organization, however higher concentration of PM10 was found at floor level in one office room. Carpet was the floor material in all the measured rooms, which may affect the particle concentration at floor level.

Conclusions: The thermal environment was acceptable with a maximum PPD of 7%. The concentration of PM2.5 and PM10 were below the recommended maximum limits in the breathing zone. However, the concentration of PM10 was high at floor level, which might cause increased PM10 in the breathing zone due to re-suspension of the particles in the air. Low levels of relative humidity were found in the measured building, which might contribute to lower performance among the office workers in addition to the development of SBS symptoms, asthma and respiratory infections. Increasing the relative humidity may improve the performance of workers in the office.

ABSTRACT. Thermal and visual comfort significantly influence the perception of an indoor environment and the subjective well-being of people in those spaces. In this context, the present research focuses on the evaluation of the indoor comfort in building type less frequently taken into account in the literature, namely a health care facility in Vienna, Austria. Short and long-term monitoring of salient parameters (air/globe temperature, relative humidity, air velocity, CO2 concentration, lighting levels) was performed and the data obtained were analyzed. For thermal comfort, PMV and PPD were calculated according to the European standard (ISO 7730). Lighting was evaluated based on the European standard EN 12464. Additionally, patients and employees were involved in indoor environmental assessment via questionnaires. The results from the measurements were then compared with the survey results. The outcome reveals a certain level of difference between patients and employees. Moreover, user’s evaluation display a considerably smaller hand-width as compared to calculated PMV results. Lighting levels are generally lower than recommended, but they were rated acceptable by patients and employees. The results point towards a slightly higher user’s satisfactory level if compared to corresponding standard based estimations.

ABSTRACT. The VELUX Group launched the Model Home 2020 project back in 2008, a vision for climate-neutral buildings with a high livability level. From 2009 to 2011, full-scale experimental demo-houses have been placed at six different locations in five countries. The domestic buildings are located in Denmark (newbuild), Germany (renovation), France (newbuild), Austria (newbuild) and in the UK (newbuild). All houses have an extensive monitoring program for the indoor environment (daylight, thermal comfort, indoor air quality and ventilation) and energy performance, as well as subjective responds from a test family living in the house for one year. The houses reflect and respond to three main principles – efficient energy design, high degree of livability and minimum climate impact – as well as the different climatic, cultural and architectural conditions of the countries in which they are built. This paper combine physical measurements of daylight and thermal comfort with Post-Occupancy Evaluation (POE) of the five families living, for one year or longer, in the Model Home 2020 houses. The POE survey is carried out seasonally during the test year the family lives in the house allowing capturing and exploring variation on a seasonal basis. The results give an indication of what the families think of the houses, of its interior environment, and how the environment is experienced. The focus is on the interaction between the high daylight levels (5% daylight factor in most main rooms) in the houses and the thermal comfort achieved, as overheating is generally avoided.

ABSTRACT. In this study we investigate the potential impacts of future climate change scenarios on overheating risk and primary energy use for space conditioning of a newly built multi-story apartment building in Växjö, Sweden. The building is district heated and potentially cooled by stand-alone air conditioners. We consider climate change scenarios for the period 2050-2059, historical climate of 1961-1990 and recent climate of 1996-2005. The climate change scenarios are based on the representative concentration pathways 4.5 and 8.5. We explore the risk of overheating of the building and analyse the impacts of different strategies for overheating control, including increased airing and solar shading besides mechanical cooling. We investigate the implications of different renewable based electricity supply options for space cooling and ventilation of the building. The results show that the space heating demand is significantly reduced and cooling demand is strongly increased for the building with the future climate scenarios. Furthermore the risk of overheating increases under the climate change scenarios. Among the overheating control strategies analysed, solar shading is the single most effective measure, giving the lowest primary energy use for space conditioning. Complementing the electricity from biomass-fired condensing power plants with solar-based electricity reduced the space conditioning primary energy use by 4-9%. Adding increased airing to the control strategies increased the primary energy use.

ABSTRACT. INTRODUCTION: During a renovation of 92 homes in Montfoort (the Netherlands) it was decided to bring 10 dwellings to an even higher energy label and to ensure an extra healthy and comfortable indoor climate for the residents of those 10 dwellings. The 10 dwellings were renovated in line with the Active House specifications (see http://www.activehouse.info/about-active-house/specification).

AIM: The aim of the study was to develop a method to objectify the health and comfort performance and perception of the indoor environment in dwellings developed in line with the Active Houses specifications.

METHODE: A questionnaire was developed based upon the results of previous projects that involved systematic evaluation of indoor environment perception and complaints. Next the test version of the questionnaire was tested in 10 Active Houses in Montfoort, The Netherlands. The Active House residents were approached twice: once during the summer period of 2015 and once during the heating season (november 2015). The findings from the field study were analyzed and the questionnaire results were reported in the ‘Active House Radar’ format (perception variant).

RESULTS: The project showed that the questionnaire allows for systematic objectivation of end user perceptions of active houses. The outcomes of the pilot project show that in this specific case (Montfoort Active Houses) residents are most satisfied with the visual comfort in the houses and are least satisfied with the thermal environment and the acoustic comfort in the houses.

ABSTRACT. Building energy simulation tools are frequently used during design stage in order to predict energy use in buildings. With the increasing need for higher energy efficiency in buildings, the discrepancy between predicted and actual measured energy performance of buildings becomes a major issue. The expected precision level of model predictions depends on the concerned application: energy performance contracts and guarantees, HVAC default detection, measurement and verification protocol, renovation decision making, etc. The objective of the present work is the development of a methodology of comparison between calculated and measured energy consumption of buildings in order to analyze the observed discrepancies and to identify their causes. It aims to give recommendations for improvements of dynamic energy calculation models and input data assessment. We present and discuss in this article the developed methodology. It is based on sensitivity and uncertainty analysis using a Meta model that approaches the response of a detailed dynamic energy model. The Meta model is constructed using fractional factorial design of experiment and on the basis of eight homogenous groups of building input parameters (climatic conditions, thermal and geometrical characteristics of envelope, parameters of occupant’s behavior, etc.). This methodology makes suitable the analysis of the impact of uncertainties of these groups of parameters and the importance of interactions between each other. The proposed methodology was applied to a real office building case, located in France and designed as a low energy building. Hourly measurements of heating, lighting and ventilation energy consumptions, climatic data and indoor temperatures were recorded during a whole year. Monthly and annual measured energy consumptions were compared to the calculated values of the dynamic energy model of the French thermal regulation. The impacts of 28 variables classified into 8 groups were investigated. Uncertainties of variables were obtained through literature review and field survey. Preliminary results show that climatic data and office usage and occupancy have a major impact on energy consumptions. By using actual measurements of climatic data and occupancy with the predictive energy modeling, the discrepancy between calculated and actual measured energy consumptions was reduced to less than 5% for heating and ventilation. The uncertainty of model prediction can be reduced with improved data collection and the use of more realistic input data. Work still in progress to apply the methodology to other real cases including a single detached dwelling and a multi-family building.

ABSTRACT. The study presents a numerical dynamic model carried out using TRNSYS and discusses the thermal performance of façade building integrated with PV modules on its west and east vertical sides. The needed thermal peak power and energy of the building were estimated added to the produced electrical energy of the installed PV system. The comparative study includes different climatic conditions within two European cities i.e. Venice and Helsinki, two locations of PV modules and two facade inner layer compositions.

ABSTRACT. The needs for energy conservation and acceptable indoor environment are raising an interest on novel building envelope technology. Window, as a weak link between outdoor and indoor environment, causes significant heat loss and thermal discomfort. Among numbers of studies, ventilated window is regarded as one of the most promising solutions, which can fulfill the needs of energy efficiency, thermal and visual comfort. Currently, the studies of ventilated windows mainly rely on complex fluid and thermal simulation software, which require extensive information, data and are often very time consuming. The aim of this paper is to develop a simplified tool to assess the thermal behavior and energy performance of ventilated windows in the early design stage. The simplified tool is developed to treat different ventilation modes: pre-heating, self-cooling and by –pass, and an operation strategy is established to determine the most energy efficient mode in each time step. Cavity air temperature and energy demand are calculated based on hourly weather data. The accuracy of the simplified tool is validated by full-scale experiments and numerical simulation. In addition, a case study on a single family house with ventilated windows in the Danish climate is present. The results indicate that ventilated windows have apparently advantages over conventional windows on the indoor thermal comfort and energy saving.

ABSTRACT. Modern low-energy buildings are often associated with efficient shading devices, as an inevitable component to reduce the peak heat gain in the building and to improve visual comfort. Internal shading devices may have inferior performance compared to external shading, but these are still the most used in practice due to lower cost, simplicity and better acceptance between architects and users.

The interplay between glazing systems and internal shading devices has been studied and in everyday practice this interplay is described by the solar shading coefficient and the total g-value of the system (window + roller blind). Solar shading coefficient in such practice is assumed to be independent of the window properties and solar incidence angle.

This paper is aimed to illustrate the deviation between the actual and assumed performance of the window system with internal roller blind. This task is carried out by experimental work in a full-scale test facility, the Cube, with two types of window (double and triple glazed) and two types of solar shading: highly reflective roller blind and highly absorbing roller blind. Danish Building simulation software, BSim is used to illustrate the scale of deviation between the experimental results and the results obtained with common assumptions for solar properties of shading device.

It is concluded that the solar shading coefficient for an internal roller blind, as a standalone parameter, is not good enough to describe the solar properties of the system, as it is proven to be angle-dependent. Further work is required to investigate the relation between the solar shading coefficient of shading device and window properties.

ABSTRACT. The passive strategies are promoted by the European Energy Performance of Buildings Directive (EPBD) 2002/91/CE and the EPBD Recast (Directive 2010/31/UE) to decrease energy demands of the construction sectors. As the buildings are using 35% of the total energy and causing roughly 25% of the global CO2 emissions, and the existing building stock represents a considerable big ratio compared to new buildings; this study approaches on existing buildings focusing on shading devices. This study obtains optimum effects of the shading devices to decrease energy consumption on a hypothetical building which has the usual features for office types in Turkey. 4 offices (8 thermal zones) are planned as getting the benefit of daylight from different façades. The main goal of this study is to give an advice about using shading devices for existing buildings in order to reduce energy demands. Within this study, OpenStudio simulation tool is used with Radiance and EnergyPlus plug-in software; in order to investigate the differences between the usages of shading devices in an office building. The alternatives will be simulated with an unshaded building for having a base for comparison. The electric, heating and cooling energy consumptions will be calculated by EnergyPlus and Radiance will be giving the daylight autonomy. Therefore we will be able to see the effects of daylight according to shading device usage. As a result; the percentage of decreasing the energy demands with the optimum shading for each orientation will be determined by comparing the base building and the other alternatives.

ABSTRACT. Biological response to daylight presents the synchronization of our biological processes, such as the body core temperature regulation, metabolism, blood flow, sleep cycles, digestion and others with the day and night cycle. These processes are known as the circadian rhythms, because they repeat approximately each 24 hours. The research of the biological response is related to the foundation of a non-visual photoreceptor ipRGC (intrinsically photosensitive retinal ganglion cells) in the retina, and it offers a new, more complex view on the evaluation of the indoor light climate in permanently occupied spaces. The efficiency of the biological stimulation depends on the amount and nature of light impinging on the retina. The biological response is provided most efficiently, when the light spectrum is dominated by the blue colour, i.e. when the circadian photoreception curve peaks in the blue light spectrum at ~450 nm, which, however, does not entirely correspond to the luminous efficiency function, which peaks at 555 nm. This discrepancy between the blue light spectrum and the luminous efficiency function can occur in indoor spaces with insufficient daylight, where artificial light helps provide the satisfactory visual comfort, but may not provide enough biological stimulation. Also internal coloured surfaces can affect our biological response to daylight. A long-term absence of biological response can result in insufficient sleep and tiredness, increased occurrence of chronic depression, bipolar disorder and seasonal affective disorder. The aim of this paper is to prove that the actual regulations, which focus solely on the visual comfort, may not be satisfactory as far as the biological stimulation is concerned. Emphasize is laid on the effect of different coloured surfaces on our biological response. For this purpose, experimental models in the scale of 1:5 were constructed, representing a deep office room exposed to natural daylight passing through the windows. Various internal coloured surfaces were applied; the reference model had all surfaces white and the other two models had a combination of either yellow or orange walls, brown floor and white ceiling. Three work zones were defined at the distance of 3 m, 6 m and 8 m from the windows. In these positions, visual conditions and biological stimulation efficiency were measured by a spectrophotometer at the height of 1.2 m above the floor, representing the eye of a sitting person with a view on a window or wall. In all positions, the modification of the natural daylight spectrum by the coloured walls was calculated by an established computational model and the efficiency of biological stimulation was estimated. The experiment showed the negative effect of the internal coloured surfaces, as the blue light was suppressed and thus the biological response was inhibited. This effect was most pronounced in the room with yellow walls, at the distance of 3 m from the window, when the biological effect was 3-times lower than for the same position in the reference room with white surfaces. The experiments have also confirmed that even at a high illuminance level the biological response to daylight can be relatively low, mainly in the winter period.

ABSTRACT. The inevitable turn of the building sector to sustainable design techniques has brought daylight analysis to the center of attention. Buildings with an enhanced daylight performance have minimized energy requirements and an improved indoor climate. However, assessing daylight conditions is somewhat adhered to old-fashioned methods, as building regulations and schemes in most countries are not updated to research findings.

Daylight Factor is the most widely used method of establishing compliance with building codes and credits within environmental assessment schemes such as BREEAM, DGNB etc. As much as this method is easy to comprehend and apply, it leaves the designer a lot of space to produce a building with uncomfortable or energy intensive daylight conditions. That is because DF takes no account of the building location, façade orientation or varying sky conditions. Moreover it provides no indication of glare or visual comfort nor is the solar shading taken into account. The latter is of increasing importance in low energy buildings since the solar shading is more often used and is vital for the expected performance of the building.

Instead the introduction of climate-based daylight calculations that rely on hourly meteorological data over the year, form much more accurate, yet simple measures of the daylight conditions in a building as it makes daylight assessments tailored to each building, whilst producing information on lighting energy savings, indoor illuminance conditions and occupant comfort. Climate based daylight metrics could effectively replace daylight factor in regulation and scheme requirements. So far the DA and UDI methods are applied by the UK Education Funding Agency for the evaluation of designs submitted for the Priority Schools Building Programme (PSBP). Furthermore a variation of DA, the so-called Spatial Daylight Autonomy (sDA) is used in the environmental ration system LEED v4 and is also proposed for the upcoming EU standard on daylight.

Four shading systems has been investigated and their daylight performance are compared on a number of different daylight metrics such as; Daylight Factor, Useful Daylight Illuminance and Daylight Autonomy. The study shows that the solution achieving the lowest daylight factor in the examined rooms was actually the solution with the most hours/working year of useful illuminance levels and with adequate daylight autonomy. So by accounting for the bespoke climatic annual conditions of the building as well as its location the design decisions for improved daylight can be altered. It underlines the importance of using the right daylight criteria in the design phase and hence also update the existing regulations and schemes to climate based daylight metrics.

ABSTRACT. Artificial lighting is one of the major electricity consumers in many non-residential buildings. Proper use of daylighting in retail buildings can reduce energy consumption effectively and additionally improve the quality of light and increase sales and worker’s productivity. The present study analyses daylight potentials and energy performance using different configurations of skylights, deflectors, clerestories and lighting zones for a large space hall-type retail building located in the northern latitude and cold climate of Finland. The scope of the study was to determine the artificial lighting energy reductions for different combinations and the general impact of daylighting features on the energy performance of the building type. The results show electric lighting energy savings potential from a mere 4% in the case of single zone control with only clerestories, up to almost 60% in the case of multi-zone control with skylights, clerestories and without deflectors. The total delivered energy shows increase between 1% and 20% for the different configurations using single zone lighting control and from 6% increase to 4% decrease in cases with multi-zone control. The primary energy results showed up to 1% lower values for single zone and up to 17% lower values for multi-zone control variants. The outcomes of the research emphasize the potential of daylighting underlining the importance of reducing glare and of a correct lighting zones design which can increase the daylight performances of about 50%.

ABSTRACT. Introduction

The use of Daylight Controlled Dimming systems (DCD systems), which reduce the artificial light levels depending on the daylight penetration, can result in substantial energy savings in school and office buildings. However, it is quite difficult to accurately estimate the actual saving potential of DCD systems. The reason for this is that the energy savings depend on a wide range of parameters. Beside building properties, climate conditions and occupant behaviour, also the type of DCD system and its commissioning affect the obtained energy savings and thus the cost effectiveness of the system. The aim of this paper is to consider the impact of the type of DCD system and its commissioning on both the energy saving potential of DCD systems and the visual comfort. Furthermore, the occupancy of the classrooms is discussed.

Methods

A 1-year monitoring campaign was carried out simultaneously in 3 classrooms in a Belgian school. Each classroom is equipped with a different type of DCD system and all rooms have identical geographical location, orientation, façade and geometry. Monitoring took place under real circumstances. The lighting energy consumption per row of luminaires parallel to the window side was measured and the occupancy of each classroom was monitored because this parameter could have a major impact on the payback period of DCD systems. In addition to this long-term monitoring, momentary illuminance measurements were carried out in order to assess the visual comfort.

Results and discussion

The occupancy of the classrooms was notably lower than expected: the monitoring results show that the occupancy of the 3 classrooms varies from 755 to 806 hours per year, compared to a default value of 2000 operating hours per year, proposed in EN15193:2007. Moreover, the lighting system of the classrooms is switched off during 24% to 28% of the yearly occupancy time (compared to 25%, proposed in EN15193:2007). The differences between the annual energy savings of the DCD systems were found to be significant, even though all classrooms in which they have been installed are equivalent: total energy savings varied from 18% to 46%, depending on the type of DCD system. Further analysis showed that monthly savings in the classroom with the most energy-saving DCD system varied from 23% in November 2014 to 85% in April 2014. The measurements of the illuminance levels in this classroom showed that there is a substantial risk that the visual comfort is not assured at certain moments.

Conclusions

The occupancy time has to be examined before deciding to invest in a DCD system, as it has a large impact on the payback period of DCD systems. Furthermore, the energy savings achieved by the DCD systems can vary strongly with the type of DCD system, apart from the building characteristics. Finally, the correct commissioning of the DCD systems turns out to be of major importance. Not only proper installation is important: the good functioning of the system has to be verified regularly in order to realize the intended energy savings and to permanently assure a satisfactory visual comfort.

ABSTRACT. Windows are the only part in buildings that can directly penetrate the solar radiation into the space and thus the shading devices are needed to control the solar penetration. Among different blind types in office buildings, optimized control strategies of slat-type blinds are suggested in the existing studies. Although many studies have been done, mostly the study focuses on window that is oriented towards the south. As it is obvious that in a real building windows can be facing any direction, in this study the effect of blinds on heating and cooling loads of a building has been done, when the design of blind is either horizontal or vertical, when it is placed either inside or outside and when the slat angle automatically changes based on either solar energy received on vertical wall or on horizontal surface (roof).

ABSTRACT. In the middle of the effort of the energy consumption reduction in buildings, the area of window at building was increasing according to the view of exterior and the method of construction. The insulation performance of window is low than the building envelope and the solar heat gain performance affects the building energy consumption of heating and cooling. The effort to improvement of the window performance was much. Also the method of verification of the window performance was proposed. This method helped designer to the choose of window. The solar heat gain performance test method by the use of solar simulator was proposed. But the measuring equipment about solar heat gain performance of window by use of natural sunlight was not developed. This study proposed the measuring equipment about solar heat gain performance of window by use of natural sunlight.

ABSTRACT. By the area of window at the envelope of building is increasing, the heat loss and heat gain through window is increasing. For decrease heat loss and heat gain through window, researchers and developers of window are effort to improvement of performance of window. At same time to the improvement of performance of window, the shading installation is important for energy savings. Previous studies confirmed an effect about the shape, installation and material of shading. But the shadings must be installed at suitable position and angle by consideration of solar altitude and performance of window. Therefore the guideline of shading design required. In this study, we confirmed the shading design factor through review about the advanced research and the regulation of Korea. And we confirmed an effect of installation of shading through energy simulation. Also we developed to form of guideline of shading design by exist guideline of shading and window. As a result, we proposed the guideline of shading design for energy saving in office buildings.

ABSTRACT. Buildings account for a significant part of the total manmade greenhouse gas emissions and energy use. Reducing CO2 emissions and energy consumption in the building sector are key issues. Optimizing the building envelope and its components is one of the main factors for reducing the energy demand of buildings.

Previous studies show that a large part of the net energy demands of an office building is related to window heat loss and cooling demands induced by solar irradiance. Windows with improved thermal transmittance (U-value) and solar heat gain coefficient (SHGC or g-value) are important for reducing the related energy demands. Windows must, however, provide daylight to the interior, implying that the visible transmittance of such glazing units must be kept at a required and satisfactory level. High visible transmittance values are traditionally difficult to achieve in conjunction with very low thermal transmittance values. Increasing the number of layers in the glazing unit of a window is an effective way of improving (i.e. reducing) the thermal transmittance value of the window.

There is a scarcity of available scientific work addressing multilayer window technologies. Hence, in this study, simulations with the aim of identifying the parameters that play a key role in improving thermal performance of multilayer glazing units have been carried out. A state-of-the-art review is presented, alongside an overview of promising new products, application cases and future perspectives and improvement possibilities for multilayer glazing technologies.

It has been found that increasing the number of glass panes in the insulating glazing units (IGU) yields U-value reductions that decrease for each added glass pane. Furthermore, improving the low-emissivity surface coatings of panes in an IGU yields little possibility for improvement compared with today’s state-of-the-art technologies. Cavity thicknesses between 8 and 16 mm were found to be optimal for IGUs with four or more panes. Reducing the gas thermal conductivity was found to have the largest impact on the U-value. The effect, however, gets less pronounced with an increased number of panes in the IGUs. Improving the low-emissivity surface coatings beyond the best-available technology has a minor effect in U-value reductions.

In addition to the thermal performance of the glazing units, optical properties, aesthetics, ageing properties and robustness should be further studied before the use of such multilayer IGUs may be recommended. Preliminary numerical simulations have demonstrated that thermal stresses to the glazing units due to high cavity temperatures can pose a problem for the robustness and lifetime of such units.