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• Affordable and adaptable VIP based internal and external retrofitting solutions. • Implementation of VIP based integral retrofitting solutions in two tertiary buildings. • Space heating energy saving analysis before and after VIP based retrofit. • Envelope heat loss coefficient reduction analysis before and after retrofitting. Vacuum insulation panels (VIPs) represent a huge opportunity to achieve nearly zero energy buildings, especially in the retrofitting of existing buildings. VIPs can be applied in conjunction with façade cladding elements, considerably reducing the heat losses or gains from the building by means of very slim wall construction systems or retrofit solutions. However, the fact that VIPs cannot be cut on-site, can be easily damaged during their handling, installation and use and have an envelope that can cause thermal bridging in the junction between panels or when combined with other materials, has hindered their penetration in the construction market. This paper presents two innovative façade retrofitting solutions, a rear ventilated façade and a stud mounted internal solution, that have tackled all these issues and provide thermal transmittances of 0.28 and 0.14 W/m2 K in relatively slim insulation systems of 10 cm widths. Solutions have been installed on the entire façade of two existing buildings located in Bilbao (Spain) and Malmö (Sweden) subjected to an integral rehabilitation process, covering 2100 m2. Buildings energy use have been monitored before and after the renovation, showing energy cuts of around 35% from pre-intervention status. This paper presents the lessons learnt during the design and installation process of the vacuum insulation integrating solutions in the façade of two existing buildings and the thermal performance results achieved after their retrofitting. [ABSTRACT FROM AUTHOR]

Highlights • A pre and post renovation energy use analysis of almost 90,000 renovated dwellings. • The (p)rebound effects explain only partly disappointing energy renovation results. • Effectiveness of renovations are dependent on state of building prior to renovation. • Effectiveness of renovations are dependent on type of occupant. • Deep renovations often save less energy than expected but are the most effective. Abstract Energy renovations often result in lower energy savings than expected. Therefore, in this study we investigate nearly 90,000 renovated dwellings in the Netherlands with pre and post renovation data of actual and calculated energy consumption. One of the main additions of this paper, compared to previous studies on thermal renovation, is that it only takes dwellings into account with the same occupants before and after renovation, using a large longitudinal dataset. Overall this paper shows new insights towards the influence of the energy efficiency state of a building prior to energy renovation, the type of building, the number of occupants, the income level of the occupants and the occupancy time on the actual energy savings, the energy saving gap and on the probability of lower energy savings than expected. We also investigate if the influence is different per type of thermal renovation measure. Some of the findings are: it is impossible to conclude which single thermal renovation measure is the most effective because this is dependent on the energy efficiency of the building prior to the energy renovation, type of building, income level and occupancy; occupants with a high income save more energy than occupants with low income; dwellings with employed occupants benefit more from improved building installations than dwellings occupied by unemployed occupants; The prebound and rebound effects are only part of the explanations for lower than expected energy savings; Deep renovations result more often in lower than expected energy savings than single renovation measures but nevertheless they result in the highest average energy saving compared to other thermal renovation measures. The results could be used for more realistic expectations of the energy reduction achieved by thermal renovations, which is important for (amongst others) policy makers, clients and contractors who make use of energy performance contracting, home owners, landlords and (social) housing associations and as a starting point to improve the energy calculation method. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) are used in novel thermal insulating materials in order to exploit their high apparent thermal capacity, which is particularly interesting for buildings with moderate thermal inertia because PCMs have a high potential for CO 2 reduction in lightweight buildings and their energy consumption as well as for increasing the thermal comfort of the inhabitants. In addition, one of the most promising applications of PCMs is embedding them directly in the insulation layers of a lightweight wall. In fact, due to their apparent thermal capacity, light insulators with embedded PCM particles have good performances in smoothing and shaving of thermal peak loads. Furthermore, in some climatic conditions, they can act as thermal storages by reducing thermal loads in buildings. Many sectors of evidence in the literature indicate that it is necessary to use a hysteresis model with two different curves of specific heat versus melting and solidification to assess the transient thermal performance of PCMs embedded precisely in an insulation layer. The main aim of this research is to develop a detailed dynamic model in order to calculate the effects of PCMs in insulation layers of lightweight walls. In this paper, the results of some actions, used to improve the effectiveness of the models, are investigated. In particular they are the adoption of two distinct c p curves, which improves the accuracy of dynamic simulations and, hence, allows the development of the model using a smaller number of points and a larger time step. Several experimental tests validate the numerical model. Furthermore, this paper presents the way in which the position of the PCM insulation layer, in a typical wallboard, affects the temperature and heat flux, inside each layer, in transient conditions. The results show that, in the case evaluated, the maximum reduction of heat consumption, of about 15%, was obtained when PCMs are located in positions three and four, which are approximately in the middle of the wall. In addition, this specific kind of insulation layer generates a delay of the maximum heat flux that is of about two hours. [ABSTRACT FROM AUTHOR]

The design of a complex power supply infrastructure and the satisfaction of the concentrated high energy demand is a constant challenge for data centre owners. Furthermore, economics of the operation and ideas of sustainability are getting more and more attention lately as well. Green data centres are designed to minimize the effect on the natural environment. One of the primary goals of such units is to decrease the energy needs both for the computing infrastructure and the supporting systems (e.g. thermal management), which can be achieved either by increasing the efficiency of processes or by integrating renewable energy sources. Present paper introduces results of an ongoing research and development cooperation between the Centre for Energy Research of the Hungarian Academy of Sciences and Persecutor Ltd., supported by the Hungarian Government’s “PIAC_13” programme. The project aims to develop a new, highly energy efficient data centre infrastructure, which is able to supply IT needs at a high-level, while minimizing power losses. Present paper focuses on decreasing power losses in the distribution and power conversion infrastructure. A power loss model, capable of supporting the optimal selection of different subsystems of the technological chain, is introduced and two case studies are shown to demonstrate the effect of different loss reduction options. [ABSTRACT FROM AUTHOR]

This paper aims to improve our knowledge of energy use and well-being in energy efficient office buildings. It explores the interrelations between forms and patterns of energy use on the one hand and user satisfaction, comfort, and well-being on the other hand. Findings are derived from qualitative and quantitative data collected in a recently finished research project in Austria. Fieldwork consisted of two qualitative case studies as well as an online-based survey amongst users of energy efficient office buildings. In addition, secondary data from energy-monitoring research was used to underpin the analysis. The results show that extremely low levels of energy use in office buildings can be aligned with high levels of well-being. Based on empirical findings the paper argues that both well-being and energy performance in office buildings are the result of a complex, on-going and intertwined process that involves various material and social elements. [ABSTRACT FROM AUTHOR]

Abstract: The shortcomings or limitations of the traditional approach to developing energy efficient buildings are that they can not determine: (1) the ideal thermophysical properties of building envelope material, where “ideal” means that such material can use ambient air temperature variation and/or solar radiation efficiently to keep the indoor air temperature in the thermal comfort range with no additional space heating or cooling; (2) the best natural ventilation strategy; (3) the minimal additional energy consumption for space heating in winter or air-conditioning in summer. To overcome these problems, some new concepts for developing energy efficient buildings are put forward in this paper. They are the ideal thermophysical properties of the building envelope material, the ideal natural ventilation rate, and a minimal additional space heating or cooling energy consumption. A new approach for determining these properties is also developed. In contrast to the traditional approach (the thermophysical properties of building envelope material are known and constant so that the relating equations describing the indoor air temperature tend to be linear differential equations), the new approach solves the inverse problem (thermophysical properties, etc. of a buildings are unknown), whose solution can be a function instead of a value. As a first step, the ideal specific heat of the building envelope material for internal thermal mass is analyzed for buildings located in various cities in different climatic regions of China, such as Beijing, Shanghai, Harbin, Urumchi, Lhasa, Kunming and Guangzhou. We found that the ideal specific heat is composed of a basic value and an excessive one which is of δ function for the cases studied. Some limitations that would need further study are introduced in the end of the paper. [Copyright &y& Elsevier]

Abstract: This paper demonstrates that by understanding how energy is consumed in the manufacturing of reinforced concrete, designers can significantly reduce the overall embodied energy of structures. Embodied energy of products can vary from country to country. Therefore, to accurately estimate the embodied energy of reinforced concrete structures, data specific to the country where they are being constructed must be used. This paper presents the assessment of embodied energy in typical RC building structures in Ireland. The most common methods used to calculate EE are evaluated in this paper and the most suitable method was applied to reinforced concrete. The EE of a typical 30MPa concrete mix in Ireland is calculated to be 1.08MJ/kg. Notably cement is credited with 68% of the total EE. The major contributors of energy consumption are identified, which should aid to minimise energy consumption and optimise efficiency. A case study is presented which compares the EE of a typical reinforced concrete structure in Ireland using two concrete mix designs. The first uses Ordinary Portland Cement, while the second uses GGBS replacing half of the cement content. As expected, the EE of the GGBS mix is significantly lower (30%) than that of its counterpart. [Copyright &y& Elsevier]

Abstract: The latest (4/04 and 5/04) versions of the Hong Kong Building Environmental Assessment Method (HK-BEAM), one covering new buildings and the other existing buildings, have been formally launched in 2005. The paper describes the building energy performance assessment method in these latest HK-BEAM versions. With the use of the energy budget approach, the assessment framework is applicable to a wide range of buildings that may comprise different mixes of premises types. The new scheme provides bonus credits for provisions that allow utilization of renewable energy sources. For existing buildings, it makes allowances for plant performance degradation and constraints to implementation of improvement measures in existing buildings. So far, the new assessment method has been applied to six building developments, including commercial complexes and residential developments. The assessment results are presented and discussed in the paper. [Copyright &y& Elsevier]

One of the long-term challenges outlined within the UK Government's Energy White Paper (2011) is to cut both greenhouse gas (GHG) emissions and energy bills by improving household energy efficiency. As such, several energy-related initiatives have, in recent years, been promoted including the Community Energy Saving Programme. In this study, we explore how patterns of user consumption as influenced by occupant awareness and behaviour, can both positively and negatively influence policy initiative delivery. In so doing, we present the results from an extensive pre- and post-retrofit home energy use and performance survey of 150 properties located in Nottingham's Aspley ward, home of one of England's pilot CESP schemes. Our results show that whilst this specific initiative significantly improved home conditions and reduced energy consumption, it failed to achieve the predicted £300 annual savings on household energy bills. This was found to be largely attributed to occupants’ ingrained habits towards household energy use, higher comfort level preferences, (lack of) energy consumption awareness, and insufficient information provided to help residents better manage their home energy use following the retrofit. By exploring some of the core lessons learned from the survey, this research seeks to inform and improve the uptake and delivery of future retrofit initiatives. [ABSTRACT FROM AUTHOR]

A building influences its surrounding external environment, and its indoor environment is usually sensitive to its surroundings. In order to obtain a more accurate prediction of the indoor thermal behaviour of a building or a building stock, it is necessary to consider the interactions between the indoor and outdoor thermal environments. The modelling approach presented in this paper is based on a building energy model and the urban modelling tool SOLENE-Microclimat. A sensitivity analysis is undertaken to highlight the parameters which influence the performance of the building model. Then, the thermal indoor behaviour of a building is compared to in situ experimental measurements and the outdoor thermal environment is evaluated in terms of external surface temperatures. The model's accuracy and behaviour is evaluated and a crossover approach with the sensitivity analysis results is proposed. The model obtains a good level of performance for almost all variables, unless some external surface temperatures intervals. [ABSTRACT FROM AUTHOR]

This research paper collects the outcomes of an experimental study focused on the energy benefits achieved by coupling an energy efficient building with a sunspace in winter season and Mediterranean climate. Acting as passive Solar heating elements, sunspaces are intended to be a valuable tool among sustainable and energy-efficient constructive and/or retrofitting strategies. In order to assess the energy saving potential of the above-mentioned coupling and relate it to the main design parameters, two operative steps were carried out: the numerical step allowed different simulated configurations to be evaluated in order to identify the optimal one from an energy perspective and physically realize it; the monitoring phase served the double purpose of calibrating the simulation model and provide on-site validated data for subsequent assessments and comparisons. Three main sunspace configurations were tested: irradiative single-glazed, irradiative double-glazed and convective double-glazed. The convective double glazed configuration was found to outperform the others since the daily energy consumption reduction exceeded the 27% (compared to the irradiative, double glazed counterpart) for all weather conditions. Besides, the activation of a mechanical ventilation system was slightly counterproductive in terms of discomfort phenomena since a less stable indoor air temperature was guaranteed. Comparing the two irradiative configurations, it was found that the addition of an extra glass layer was responsible of a quite constant reduction of 1 kW h/day, thus increasing the percent heating energy demand saving achieved through the insertion of the sunspace from approximately 3,3%–8,7%, while minimizing indoor air temperature fluctuations too. [ABSTRACT FROM AUTHOR]

Abstract: Separate heat pipe heat exchanger (SHP heat exchanger) transports heat from the indoor air to the outdoor air by making use of the temperature difference. It consumes much less energy than split air-conditioners in telecommunication base stations (TBSs) because of no compressor. In this paper an annual energy-using simulation module of SHP was built up in the building energy simulation tool DeST. The SHP model was basing on the theoretical and experiment results of the heat transfer performance and the energy consumption. As the heat transfer quantity of SHP was interplayed with the indoor air temperature, the solution for the models of the dynamic thermal process in building and SHP heat exchanger was the key part, which was carried out by the coupling calculation. The reliability of SHP model and the coupling solution was verified by an empirical test. Finally, case study on the design of air-conditioning systems in TBSs was carried out to illustrate the engineering applications of SHP module. [Copyright &y& Elsevier]

Abstract: In Yangtze River area in China, the temperature in the transitional seasons is moderate but the humidity is high so that the inhabitants feel uncomfortable, thus, the air needs to be dehumidified without lowering the temperature (isothermal dehumidification). In this paper, a novel isothermal dehumidification method in a room air-conditioner is discussed. The system can switch between cooling mode and isothermal dehumidification mode by switching valves, and the indoor reheat coil can be utilized as evaporator in the cooling mode. Through experimental study, the dehumidification capacity, energy efficiency ratio, and energy consumption are studied and fitting formula are given. The results show that the dehumidification capacity is 1.08–3.2kg/h, which could meet the isothermal dehumidification demand of an average residential apartment. The dehumidification EER was 1.13–2.5, and the outlet temperature of the unit was 0–2.4°C lower than the inlet temperature. [Copyright &y& Elsevier]

Abstract: Although there have been multiple studies on window thermal properties in energy-efficient fenestration design, the effects of building geometry factors have been studied much less. The study presented in this paper evaluated the role of geometry factors, such as window orientation, window to wall ratio, and room width to depth ratio, on building energy performance in a commercial office building. A series of energy simulations were performed for six climate zones in the United States using a model of a room in a typical office building created in Design Builder, an energy analysis program, to evaluate total annual energy consumption. The simulation results were analyzed to find the combination of parameters yielding the lowest energy consumption and to define potential energy savings for office buildings located in various climate zones. The study showed that geometry factors affect energy consumption significantly in hot climates (Zones 2 and 3) and cold climates (Zones 6 and 7) but only marginally in temperate climates (Zones 4 and 5). Energy savings were on average 3% and 6% reaching a maximum of 10% and 14% in hot climates (Zones 2 and 3) and 1% in temperate and cold climates (Zones 4–7). [Copyright &y& Elsevier]

Abstract: Manual ventilation of dwellings in winter consumes excess heating energy, as cold outdoor air replaces warm indoor air. The German government promotes ‘shock-ventilation’ (Stoßlüften), where all windows are opened simultaneously, fully and briefly, to minimise energy wastage. However, the predominant design of windows in Germany''s housing stock mitigates against this strategy, as these windows open inwards while their indoor ledges provide ideal storage for pot-plants and other objects, blocking normal opening. An alternative window setting, long periods of trickle-ventilation, can consume up to 20 times as much energy as shock-ventilation. This paper reports a pilot study of household ventilation capabilities and practices in the German municipality of Aachen. A statistical analysis indicates 29% of dwellings have sufficiently unimpeded windows to facilitate shock-ventilation, while householder interviews reveal reasons for reliance on trickle-ventilation, including convenience and underestimation of its energy consumption. Analysis of results using ‘social practice theory’ suggests three possible policy interventions to improve energy-efficiency of ventilation. The results suggest the need for a nationwide study to quantify energy wastage through mismanaged ventilation, not least because of its possible cost to the country, of several billion Euros annually, and the millions of tonnes of CO2 emissions it most likely causes. [Copyright &y& Elsevier]

Abstract: The control of indoor thermal comfort in buildings through thermal inertia during the summer season plays a fundamental role in the design of energy efficient buildings, especially in the Mediterranean climate. In fact, lightweight, highly insulated buildings cannot provide the necessary mass to buffer thermal gains. Phase change materials (PCM) have been used to provide lightweight building components with the required thermal inertia without increasing their overall mass. So far the integration of PCM into lightweight piped radiant floors for the control of thermal comfort during summer cooling regimes has not been investigated. This paper reports the development of a lightweight piped radiant floor prototype with an integrated PCM layer aimed at buffering internal gains at constant temperature during summer cooling regimes without affecting its winter warming capacity. Both the construction of the laboratory specimens and the development of the optimized finite element models are detailed and the assessment of the floor performance in a simulated room is discussed. [Copyright &y& Elsevier]

Abstract: This paper presents a thermoeconomic analysis of a trigeneration system interacting with the economic environment. The aim is to determine the energy and total costs of internal flows and final energy services (electricity, cooling and heat). One of the main difficulties in calculating these costs in trigeneration plants within buildings is the continuous variation of energy supply services. Fuel prices and purchase/sale electricity tariffs can also vary. As a consequence there are different operation conditions that combine the possibilities of purchasing or selling electricity, consuming heat from auxiliary boilers, and wasting the excess of cogenerated heat. A novel cost allocation method valid for all possible operation conditions of the trigeneration system is proposed. The heat produced by cogeneration modules is disaggregated into three fractions: heat that meets the heat demand directly, heat utilized to drive absorption chillers (producing cooling), and heat dissipated to the environment. Cost allocation to all cogeneration co-products is determined by applying the principle of avoided expenditures. The cost allocation proposal is applied to a trigeneration system providing energy services to a hospital with 500 beds located in Zaragoza (Spain), encouraging rational and efficient energy services production and consumption. [Copyright &y& Elsevier]

Abstract: The thermal performance of windows is important for energy efficient buildings. Windows typically account for about 30–50 percent of the transmission losses though the building envelope, even if their area fraction of the envelope is far less. The reason for this can be found by comparing the thermal transmittance (U-factor) of windows to the U-factor of their opaque counterparts (wall, roof and floor constructions). In well insulated buildings the U-factor of walls, roofs and floors can be between 0.1 and 0.2W/(m2 K). The best windows have U-factors of about 0.7–1.0. It is therefore obvious that the U-factor of windows needs to be reduced, even though looking at the whole energy balance for windows (i.e., solar gains minus transmission losses) makes the picture more complex. In high performance windows the frame design and material use are of utmost importance, as the frame performance is usually the limiting factor for reducing the total window U-factor further. This paper describes simulation studies analyzing the effects on frame and edge-of-glass U-factors of different surface emissivities as well as frame material and spacer conductivities. The goal of this work is to define material research targets for window frame components that will result in better frame thermal performance than is exhibited by the best products available on the market today. [Copyright &y& Elsevier]

Abstract: The concept of Zero Energy Building (ZEB) has gained wide international attention during last few years and is now seen as the future target for the design of buildings. However, before being fully implemented in the national building codes and international standards, the ZEB concept requires clear and consistent definition and a commonly agreed energy calculation methodology. The most important issues that should be given special attention before developing a new ZEB definition are: (1) the metric of the balance, (2) the balancing period, (3) the type of energy use included in the balance, (4) the type of energy balance, (5) the accepted renewable energy supply options, (6) the connection to the energy infrastructure and (7) the requirements for the energy efficiency, the indoor climate and in case of gird connected ZEB for the building–grid interaction. This paper focuses on the review of the most of the existing ZEB definitions and the various approaches towards possible ZEB calculation methodologies. It presents and discusses possible answers to the abovementioned issues in order to facilitate the development of a consistent ZEB definition and a robust energy calculation methodology. [Copyright &y& Elsevier]

Abstract: The growing worldwide demand for energy is basically satisfied through natural resources such as oil or natural gas generally acknowledged as being responsible for climate change through greenhouse gas emissions. The building sector accumulates approximately a third of the final energy consumption. Consequently, the improvement of the energy efficiency in buildings has become an essential instrument in the energy policies to ensure the energy supply in the mid to long term, and to meet the targets stated in the Kyoto Protocol. During the last decade and being sensitive to this fact, many national governments and international organizations have developed new regulations to achieve those targets. One of these regulations is the European Energy Performance of Buildings Directive but, to date this certification does not follow a standard procedure which is universally accepted. This paper aims to contribute to this standardization, proposing an energy efficiency index for buildings that relates the energy consumption within a building to reference consumption. The proposed energy index can be obtained in a simple manner by combination standard measurements of energy consumption, simulation and public databases. Furthermore, the index is upgradable whenever new data are available. [Copyright &y& Elsevier]

Abstract: From energy statistics (primary energy consumption) and a few Census data (residential buildings floor area) the average specific primary energy use (kWh/m2) of a territorial (Regional or National) building stock may be easily evaluated. However, can we achieve a deeper insight on this building stock using basically the same data bases? This is the question which this paper is aiming at, and the results is an analytical methodology to determine the Statistical Distribution Of residential Buildings according to primary Energy consumption for heating purposes (E-SDOB) at a Regional or National scale. This tool may allow the legislator to define a performance scale for building energy certification, to introduce mandatory measures and incentives for building energy retrofits, to evaluate the potential of new technologies, etc. The main source of data required for determining E-SDOB is still the National Census, but it has to be integrated by energy standards and laws, literature and a few data taken from the authors’ experience and in situ analysis. The results obtained have been compared with those derived from two Italian Regional (Piedmont and Lombardy) energy statistics, with excellent agreement. [Copyright &y& Elsevier]

Abstract: In this paper, we propose a vision-based system for human detection and activity analysis in indoor environment. The developed presence sensor is based on video analysis, using a static camera. Composed of three main steps, the first one consists in change detection using a background model updated at different levels to manage the most common variations of the environment. Second, a moving objects tracking, based on interest points, is performed. Third, in order to know the nature of the various objects that could be present in the scene, multiple cascades of boosted classifiers are used. The validation protocol, defined by the industrial partners involved in the CAPTHOM project focusing among other things on “Energy Management in Building”, is then detailed. Three applications integrated into the CAPTHOM project illustrate how the developed system can help in collecting useful information for the building management system. Occupancy detection and people counting as well as activity characterization and 3D location extend to a wide variety of buildings technology research areas such as human-centered environmental control including heating adjustment and demand-controlled ventilation, but also security and energy efficient buildings. [ABSTRACT FROM AUTHOR]

Abstract: This paper attempts to formulate Overall Thermal Transfer Value (OTTV) coefficients for Composite, Hot-Dry and Warm-Humid climates, the three main tropical climates in India. Four existing air-conditioned office buildings – two mid-rise and two high-rise were modeled as case studies using eQuest v.3.6, which is a DoE2.2, based building energy simulation tool. Based on the study of building envelope, loads, operation and HVAC system characteristics of these case study buildings, a hypothetical high-rise, 16 storey office building, octagonal in plan was created for parametric studies. 98 types of opaque exterior wall constructions and 93 types of glass constructions were varied sequentially in parametric runs to obtain results for hourly wall conduction, glass conduction and glass radiation heat flow in eight orientations for each of the climate type. These hourly results were processed to obtain annual heat gain intensities for each parametric case for all three modes of heat transfer. Regression analysis was used to obtain the OTTV coefficients –TD eq, DT and SF for the three climates. A new OTTV equation is obtained and presented. The set of coefficients obtained were verified by calculating the OTTV for the four case study buildings, for various parametric runs. The computed OTTV for the four case study buildings exhibits good linear correlation with the annual space cooling plus heating energy use in three climates. [ABSTRACT FROM AUTHOR]

Abstract: Minimizing energy consumption in buildings has become an important goal in architecture and urban planning in recent years. Guidelines were developed for each climatic zone aiming at increasing solar exposure for buildings in cold climates and at reducing solar exposure for buildings in hot climates. This approach usually plans for the season with the harshest weather; often forgetting that temperatures in cities at latitude 25° can drop below thermal comfort limits in winter and that temperatures in cities at latitude 48° often rise above thermal comfort limits in summer. This paper argues that a holistic approach to energy efficient building forms is needed. It demonstrates a generic energy efficient building form derived by cutting solar profiles in a conventional block. Results show that the proposed building form, the Residential Solar Block (RSB), can maximize solar energy falling on facades and minimize solar energy falling on roofs and on the ground surrounding buildings in an urban area in winter; thus maximizing the potential of passive utilization of solar energy. The RSB also supports strategies for mitigating the urban heat island through increased airflow between buildings, the promotion of marketable green roofs and the reduction of transportation energy. [Copyright &y& Elsevier]

Abstract: Conditioning and ventilating open office spaces requires innovations as new buildings aim to be more intelligent, energy efficient and healthy. This paper explores the possibility of using a localized airflow to divide an open cubicle office into zones without partition walls. Computational fluid dynamics (CFD) model was used to simulate localized airflow in a cubicle office and both the energy and the indoor air quality concerns were addressed. The findings suggest that (1) localized airflow is plausible for zoning purposes, (2) localized airflow can result in both temperature and pollutant concentration segregations, (3) temperature segregations provide possible energy savings if coupled with occupancy-based HVAC control, and finally (4) limited air mixing between zones provide a novel way for better ventilation and indoor contaminant control. [Copyright &y& Elsevier]

Abstract: This paper presents a detailed meta-analysis of end and primary energy use for heating, cooling and ventilation of 11 low-energy non-residential buildings and one residential building in Germany that belong to the EnOB research program launched by the German Federal Ministry for Economy. In particular, the analysis emphasizes the substantial impact of auxiliary energy use on the efficiency of heating and cooling performance. The investigated buildings employ environmental energy sources and sinks – such as the ground, ground water, rainwater and the ambient air – in combination with thermo-active building systems. These concepts are promising approaches for slashing the primary energy use of buildings without violating occupant thermal comfort. A limited primary energy use of about 100kWhprim/(m2 neta) as a target for the complete building service technology (HVAC and lighting) was postulated for all buildings presented. With respect to this premise, a comprehensive long-term monitoring in high time resolution was carried out over the course of two to five years, with an accompanying commissioning of the building performance. Measurements include the energy use for heating, cooling, and ventilation, as well as the auxiliary equipment, the performance of the environmental heat source and sink, and local climatic site conditions. [Copyright &y& Elsevier]

Abstract: Increased awareness on environmental issues, together with requirements imposed by implementation of energy efficiency codes, has generated the need for tools that evaluate thermal performance of buildings. Their objective is to ensure compliance and certification. However, existing computer models are still rudimentary with many limitations for use in early design stages of any architectural project. They require exact data in a stage when designers consider conceptual ideas from a range of options rather than precise details and numbers. Design tools that suggest solutions based on ideas are rare. This disadvantage can be seen in the planning of intelligent facades, where the number of possible configurations can be overwhelming and decisions made in early stages have profound effects on energy and comfort performance. This paper presents NewFacades, a model that helps pass from ideas to significant concepts in the design of intelligent facades. It uses energy and visual comfort strategies abstracted from a prescriptive energy code for hot climates to suggest a range of good starting solutions. Designers can have energy and visual comfort estimations to these alternatives through an advanced stage energy simulation program such as EnergyPlus, or explore them further with other tools. Methods used by the tool are presented here in the context of sample cases. By working on energy principles or relying on local existing energy standards, the model can be extended to all types of climates. [Copyright &y& Elsevier]

Abstract: Building cooling heating & power (BCHP) system has advantages of energy saving and environment protection. Accurate feasibility evaluation and rational match between energy supply and energy demands are necessary for the realization of advantages of BCHP system. The influence of energy demands on the optimal facility scheme and feasibility of BCHP system needs especially to be studied. Mixed-integer nonlinear programming model is established with integrated optimization of facility scheme and operation strategy of BCHP system. A series of energy demands with different heat-electricity ratio and cooling-electricity ratio are achieved based on the energy demands of a hotel. Sensitivity analysis about energy demands ratios is carried out in this paper to study their influence on optimal capacity of facilities and feasibility indices. And the reason of the results is analyzed. Indices of feasibility evaluation include annual cost, annual cost saving rate and annual natural gas saving rate. It is shown in result that energy demands of different type have different weight in optimal capacities. Optimal capacities of facilities should be designed with consideration of all three kinds of energy demands. Different feasibility evaluation are achieved with different indices. The BCHP system is preferable for buildings with high heat demand. [Copyright &y& Elsevier]

Abstract: The paper deals with the experience in the field of arrangement of the building certification system in Lithuania. The arranged document provides the energy consumption in a building to estimate according to the calculation results, including heat losses through the building envelope elements, due to the ventilation, air infiltration and domestic hot water. The reference U-values for the building elements representing the best 50% of the building stock are derived. The changes in the energy consumption and reference values in regard with building renovation development are discussed. [Copyright &y& Elsevier]

Abstract: ParaSol is a computer program for calculating the solar and thermal properties of windows with sunshades and the energy demands of a room with a window/shading system. The program has three main features. One of them is a calculation of g, T and U for normal incidence of beam irradiation, which is performed as soon as a window or an internal/interpane sunshade is selected. The other two are based on yearly simulations, using DEROB-LTH, a building energy simulation program on which ParaSol is based. One of the applications gives the monthly average of g and T for the window glazing and the glazing/sunshade system. The other application gives the heating and cooling demands for a room with a window, with and without a sunshade, where input data are given for the internal heat, ventilation settings, shading control and temperature set-points. Version 3.0 of ParaSol, which has some new and improved models, is described in this paper. The g-values obtained with this program version are compared with measurements on windows with internal/interpane screens/venetian blinds. The absolute deviation is less than 0.03 for the venetian blinds. The measured values of dark internal screens with closed air gaps exceed those simulated by Parasol, but are lower than the ones simulated with open air gaps. [Copyright &y& Elsevier]

Abstract: The purpose of this paper is to clarify energy performance of the cooling plant system in the industrial building using actual measured operating data and numerical simulation analysis. One aspect of industrial buildings is that they have large energy consumption for manufacturing and air-conditioning compared with office and commercial buildings. Some examples of high-efficiency technologies installed in this particular cooling plant system are inverter chillers, integrated cooling towers and a free-cooling system. The inverter chiller which has been put on the market recently is state-of-the-art technology. The maximum COP of the inverter chiller reaches about 18 under certain conditions and integrated cooling towers make lower temperature cooling water as the whole capacity is large. Actual operating data indicates satisfied values for chiller and system COP during the running period and the simulation results show that the cooling plant system can cut down annual electric power consumption by about 48% compared with conventional cooling system. [Copyright &y& Elsevier]

Nowadays, the most common characteristic of all regulations and buildings is that heat energy requirement of a building is calculated and evaluated for the whole building, not as a sum of those for individual building components. In this paper, first, the recently revised Turkish standard is described in general, and then compared with the ISO 9164, EN 832 and the German regulation. The calculation procedures presented in the standards are evaluated, based on the results of three different types of buildings. The new TS 825 is an application of ISO 9164 in every respect. It uses the same equation, same restriction and same flexibility. EN 832 is basically similar to the ISO 9164 and so is the new TS 825. The most important difference in EN 832 is that solar energy gain is calculated in quite detail including passive solar gains, as well as direct solar gains. This approach gives more accurate results but need huge and detailed database. German regulation is harmonious with ISO 9164, EN 832 and TS 825 only from the point of view of principles and concepts. However, it is a very simplified one, the calculation method defined in the German regulation gave Qyear far from the actual heating energy requirement of buildings for the countries with moderate climate. The main differences between the calculation methods presented in the standards are “the acceptance of climatic data,” “the calculation method of internal heat gains,” “the calculation method of solar heat gains” and “the acceptance of the air change rate values.”The effects of parameters and the building types on the energy demands are discussed in order to determine which parameter should be constant but which ones should be variable, to obtain more simple but accurate results, and to show to designers the parameters to be effectively controlled to decrease the energy requirements of the buildings. Independently of building type, the higher the area of component, the more influential is its U-value on the Qyear except ground. Ground has always the least effect on the Qyear. The effect of air change rate is high being almost similar for all types of buildings, however air change rate affects Qyear slightly less at the terraced office building than the others. With lower U-values of wall and window, the effects of window area and window directions on the Qyear of detached buildings are minimized. Terraced buildings are more sensitive to window area than the window directions. It is clear that the increase in south window area, for all types of buildings, has slightly more effect on Qyear than the increase in north, east and west window areas. The effects of r and g on the Qyear increase, when the heat loss decreases but solar gain increases. Therefore, for modern buildings, to accept these parameters as a constant is not fairly significant. [Copyright &y& Elsevier]

The design of buildings is a multi-criterion optimization problem, there always being a trade-off to be made between capital expenditure, operating cost, and occupant thermal comfort. This paper investigates the application of a multi-objective genetic algorithm (MOGA) search method in the identification of the optimum pay-off characteristic between the energy cost of a building and the the occupant thermal discomfort. Results are presented for the pay-off characteristics between energy cost and zone thermal comfort, for three design days and three building weights. Inspection of the solutions indicates that the MOGA is able to find the optimum pay-off characteristic between the daily energy cost and zone thermal comfort. It can be concluded that multi-criterion genetic algorithm search methods offer great potential for the identification of the pay-off between the elements of building thermal design, and as such can help inform the building design process. [Copyright &y& Elsevier]

The energy renovation of existing buildings is an important tool for the reduction of energy consumption in the building sector, the improvement of prevailing indoor thermal comfort conditions and also for the improvement of environmental conditions in urban areas. At the same time, it is a technical, economic and social problem, due to the way in which many cities have been built and the restrictions imposed by economic constrains that tantalise most countries in South-Eastern Europe, and also Greece. It applies particularly in Northern Greece, with its cold and prolonged heating season, where a series of studies was carried out since 1994 to approach the problem and develop viable proposals. Public and mixed-use buildings form a significant part of the building stock and are therefore a primary candidate for energy saving measures, especially as they also play the role of a ‘pilot-demonstrator’ for the private owned buildings. However, due to the low energy prices that prevailed over the last 10 years, and as energy saving measurements are capital intensive investments, little was done in that direction. The recent sharp increase in oil prices proved that this was a short-sighted policy. In the following paper are presented the results of a study that aimed to determine the potential of energy saving renovation measures, in a representative sample of buildings under realistic conditions, to evaluate the feasibility of these measures, and also the way in which this feasibility is being analysed, under the rapidly changing economic conditions. [Copyright &y& Elsevier]