Search

This paper illustrates an energy upgrading proposal of a historical building in Naples (Italy): Palazzo Fuga, better known as the Real Albergo dei Poveri which was built in the second half of the XVIII century. The proposal consists of energy efficiency interventions on the building envelope and its plants. As energetic and thermal aspects are concerned, simulations were performed in order to size a photovoltaic system, considering lighting aspects, and to evaluate the improvement of the building energy performance. Furthermore, thermal and lighting measurements were performed with a double aim: to verify the factual state of the building and to calibrate the calculation tools to the particular situation. In this paper obtained results concerning the feasibility of interventions will be presented and discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • nZEBs in Eastern Europe lack carbon neutrality metrics and targets. • Performance requirements for nZEBs in Eastern Europe are presented. • Eastern Europe needs strategy and local governance for nZEB market penetration. • EPCs require major reform, and effective monitoring of nZEB performance is needed. • The cost-optimality calculation method must be adopted to ensure cost-effective market uptake. The European Unions' ambition for the construction sector is to be carbon neutral by 2030 for new construction. Since 2021, all new buildings in the EU should have been constructed as nearly zero-energy buildings (nZEB). However, Eastern European countries struggle to implement the 2018 Energy Performance of Building Directive recast requirements. Next to the economic challenges, equally essential factors hinder renovating the existing residential building stock and adding newly constructed high-performance buildings sourced primarily from renewable energy sources. Therefore, this study provides a cross-study to identify the barriers to nZEB implementation in ten Eastern European countries, including Bulgaria, Croatia, Czechia, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, and Slovakia. The study was conducted between 2019 and 2021 and provides an overview of prospects for nZEB in Eastern Europe. The study examines the challenges of nZEB plans faced in those countries and provides constructive recommendations. The regulations and definitions regarding nZEB energy performance, cooling and heating energy demand, thermal comfort, onsite renewables, and construction quality were analyzed. Results show that most Eastern European countries are unprepared to comply with the EPBD guidelines and cost-optimality approach. The paper ranks each country and recommends specific measures to refine the nZEB definitions. The paper provides a thorough comparative assessment and benchmarking of select EU geography that can help shift the identified gaps into opportunities for the future development of climate-neutral high-performance buildings. [ABSTRACT FROM AUTHOR]

Abstract: The paper suggests a multi-criteria approach for the energy refurbishment of historical buildings, proposing methodologies for the performance analysis, coupling several experimental and numerical studies. The target consisted in a rigorous evaluation procedure, in order to guarantee the necessary reliability of a numerical model of the system “building envelope/technical plants”, on which testing the technical and economical convenience of energy retrofit solutions. The paper collects the long work carried out by several Institutions during the last years, on Building “Palazzo dell’Aquila Bosco-Lucarelli”, a historical building located in Benevento (Southern Italy), currently analyzed in order to define the technical adoption of possible improving actions. The carried out studies, beyond the proposition of an operational methodology, are aimed to evidence a best-practice specified for the Italian territorial context, which has several historical buildings needing restoration. Carefully applied investigations, based on various methodologies and through several instrumentations, allowed the definition of a numerical model correspondent to the real building, defined also comparing the results with the historical requests of gas and electricity. Moreover, dynamic energy simulations tested the effectiveness, singularly and coupled, of several solutions for the building energy optimization. A significant potentiality of energy and economic optimization has been demonstrated. [Copyright &y& Elsevier]

The paper briefly describes energy-efficiency standards that have been issued for residential buildings in Northern and Central China as well as energy-efficiency inspection standards and specifications for renovation of existing residential heating systems in Northern China, and development of energy-efficiency standards for Southern China. The paper also describes barriers to improving the energy efficiency of residential buildings in China and strategies for overcoming these barriers, including reform of the method of payment for heating in Northern China. Finally, future prospects for further developing energy-efficiency standards for residential buildings in China are addressed. [Copyright &y& Elsevier]

Museums are buildings of particular significance due to their function and their status. At the same time they are buildings in which the principles of energy conservation are rarely applied, sometimes without reason. It has been decided by the Hellenic Ministry of Culture to convert a medieval tower, built in the year 1344 as a fortress with 0.8–1.5 m thick walls and almost no windows, into a museum. The present paper discusses the difficulties that arise in the attempt to balance between the indoor climate conditions necessary to protect the exhibits and to provide comfortable conditions to the visitors, whilst respecting the aesthetics and the historical significance of the building. Furthermore, one needs to consider the difficult but necessary task of assessing factors such as the building’s shell’s thermal conductivity and capacity, the ventilation necessary as well as the indoor air movement, in order to determine the cooling loads. Finally, the challenge lies in designing and dimensioning an effective and efficient HVAC system, which should be as discrete as possible. The present paper aims to present the results of the study, to discuss the expected energy behaviour of the building and to comment on the options for introducing energy conservation techniques. [Copyright &y& Elsevier]

This paper presents test methods and results of assessment data necessary for determination of building energy consumption, based on measurements in an occupied typical single-family house in Poland. Comprehensive on-site measurements included the building envelope, heating system, domestic hot water system, ventilation system with heat recovery and indoor environment quality. A new wireless measurement system was used. The results obtained from the thermal diagnostics were used to analyze the energy consumption of the house in four different successive building modernization stages. The steps undertaken included improvement of wall and window insulation, installation of mechanical ventilation with heat recovery, improvement of house airtightness and replacement of the boiler and the hot water storage vessel with more efficient ones. Such steps are typical activities undertaken without a prior energy analysis by owners of single-family houses. Before thermal renovation the indicator of non-renewable primary energy was 243 kWh/(m 2 y) and after renovation this decreased to 147 kWh/(m 2 y). Proper selection of thermo-modernization measures would allow to reach the lower value of this indicator. However, it still would be higher than the required for newly built single-family houses in Poland. The execution of thermal diagnostics both before and after thermal renovation of the house enable the correct performance of that process and the achievement of greater energy savings. [ABSTRACT FROM AUTHOR]

This paper presents the SOLEN integrated online tool, dedicated to citizens and local authorities. This methodology, developed to allow precise energy assessment (heating, cooling, ventilation, lighting, appliances, and cooking but also local production of renewable energy) of household energy uses, is firstly introduced. SOLEN uses a typological classification of buildings and thermal simulations. Many parameters are defined and taken into account to capture the specificities of numerous types of buildings exhaustively (e.g. type of buildings; number of floors; common ownership; orientation; thermal performances of the walls, floors, roofs, and windows; and ventilation type). These results related to building energy consumption are then crossed, in an integrated approach, with several indicators of urban sustainability, to take into account in the balance of the impact of the location of buildings on transportation energy consumption or the impact of the urban form on the production of solar renewable energy. This tool makes accessible to a large non-specialized audience the results of a three-year scientific research study in Wallonia (Belgium) and was awarded an Energy Globe Award (Belgium) in 2014. The first feedback from users is presented to conclude this contribution. [ABSTRACT FROM AUTHOR]

Policy makers have realized that without significant increases in the energy efficiency and notable reductions in the energy use of the household sector, it will be impossible to lower carbon dioxide emissions and mitigate the risks of climate change at the global level. The energy demand in residential buildings is influenced by several parameters, such as national economic growth, climate and weather, demographic structure, and technological development. In this paper, we analyze the determinants of electricity and natural gas consumptions in Italy during the period from 2004 to 2013. We provide estimates of price and income elasticities of the demand for both the energy sources in the residential sector. The role played by both energy price and household income is worth attention because it provides evidence for the occurrence of the direct rebound effect. Therefore, the economic drivers of the energy demand are important to improve the policies meant to reduce greenhouse gas emissions and contrast the global warming. [ABSTRACT FROM AUTHOR]

• This paper conducts assessment of hybrid renewable systems for urban buildings. • A new demand model for heterogeneous building types is developed. • Time series forecast of electricity market is proposed. • Novel renewable supply and balance scenarios are developed. • Techno-economic assessment of hybrid renewable systems shows feasibility. This research conducts a technical and economic feasibility study of multi-energy hybrid systems (MEHS) combining different renewables for a northern climate city of Finland to address issues of replacing fossil energy by renewable energy sources (RES) to achieve zero carbon emissions. The renewable energy systems MEHS include geothermal, biomass and solar energy. The selected city-study site is the Olympic Training Center occupied by heterogeneous buildings which presents a good representative urban city for the assessment of the energy supply and demand. A generic and integrated modeling framework grounded in a combination of novel forecasting models for the heterogeneous building energy demands, the splitting of space heating and hot water use, the coupled renewable energy generation, and the time series electricity market is developed to investigate optimal MEHS configurations based on the technical and financial analysis. Innovative scenarios of MEHS are developed. The analysis results show that MEHS can flexibly meet the energy demand for the heterogeneous buildings and the optimal configurations can be realised by an innovative integration of geothermal and solar sources as well as electricity as complementary energy. Model uncertainty and its impacts on the analysis are also considered and discussed. [ABSTRACT FROM AUTHOR]

There is an increasing desire by managers to reduce the amount of energy consumed by the buildings in their portfolio. Energy efficiency measures on existing buildings, however, are often economically feasible only if executed at the same time as the execution of necessary maintenance and refurbishment measures. At the strategic level it would be useful to be able to better plan the costs and benefits of energy efficiency measures so that decisions could be made to execute them when the opportunity arises. In this paper, a Cost-Performance-Indicator (CPI) curve is proposed to indicate additional costs and benefits of energy efficiency measures at a strategic level, and evidence is given that corroborates the hypothesis that energy efficiency measures follow the law of increasing relative costs. The usefulness of the CPI curve is demonstrated through two case studies. An example is provided and the potential is discussed for using this curve for the planning and budgeting of refurbishment and energy efficiency measures, and as a tool to explain the relation between costs and benefits of measures enhancing building energy efficiency, including the production of renewable energy, to investors. [ABSTRACT FROM AUTHOR]

The current rate structures for the electricity retailing exposes utility providers to the full wholesale market risks, and fail to incentivize end-use customers to better estimate and track their loads. In this paper, we propose a Cost-for-Deviation (CfD) retail-pricing scheme, which is designed to minimize the demand uncertainty of individual customers or communities. We formulate day-ahead planning and real-time tracking optimization problems for individual buildings. We also formulate CfD pricing scheme for community of two buildings and devise a collaboration scheme by which the two buildings negotiate. Both centralized and distributed negotiation mechanisms are presented, and the significance of adopting a transaction cost for fair-trading is discussed. A series of experiments demonstrate that CfD pricing is able to reduce demand uncertainty in a building or a community. Hence, a community’s cost of hedging quantity risk in the real-time market also reduces. Our conjecture is that by the virtue of end users being in a position to closely monitor their daily loads and by paying fines for not adhering to their plans would ultimately benefit energy efficiency and will reduce infrastructure costs. [ABSTRACT FROM AUTHOR]

Energy saving and its efficient utilization is of prime interest in today's world due to the limited energy resources and growing significance of environmental issues. Despite the intensive efforts to narrow the gap between conventional energy sources (wood, coal, gas, oil, etc.) and renewables, renewable energy resources currently supply only about 14% of total world energy demand. In this regard, energy management and optimization are considered compulsory as much as the clean energy generation. Recent works indicate that the buildings play a significant role on global energy consumption. They are responsible for about 40% of global energy demand. Among the different building types, domestic buildings have the largest share with 63% and most of energy is utilized for heating, ventilation and air conditioning ( HVAC ) systems in those buildings. Energy consumption levels of buildings can be notably reduced through waste heat recovery in HVAC systems. There are several attempts in literature addressing the possibility of decreasing energy consumption of buildings via waste heat recovery technologies. The heat recovery technologies are cost effective and user friendly applications. The use of heat recovery systems aims at mitigating the energy consumption for HVAC applications as well as the greenhouse gas emissions, and hence decreasing the adverse effects of global warming on the Earth. It is well-documented in literature that the heat recovery systems are very promising for domestic applications. In this paper, experimental results of a novel heat recovery system developed for low-carbon buildings are presented. The proposed heat recovery system consists of a plate-type heat exchanger, blower fans and ducts. The parallel-flow arrangement is used to run the system. The system is designed as under roof application. The aim of the system is to recover waste heat and to preheat fresh air using stale air. The experiments of the system are carried out in winter season in Kent, UK. The study aims to investigate the coefficient of performance ( COP ) of the system as well as the heat recovery efficiency. The results show that the heat recovery efficiency of the proposed system is around 89% while the COP is 4.5. The proposed system can be used in both winter and summer conditions without requiring additional work. Its labor cost is extremely low, so it is cost-effective and user friendly. [ABSTRACT FROM AUTHOR]

This paper shows development of a simple, cheap “Building Energy Management System” (BEMS) to monitor energy consumption, and an application to measure energy consumption, including electricity and gas consumption in buildings. The system uses current transformers to measure electric consumption at each distribution box. Web cameras monitor lighting in each room, as well as air conditioning status by recognizing the movement of a ribbon at the outlet. Web cameras can also monitor gas consumption at the meter through character recognition. The data is sent via network to a computer for monitoring and analysis. As an example, key components of this BEMS were tested to measure building energy consumption of Osaka City University Sugimoto Campus in Japan for a period of 2 years (2013, 2014). The electric consumption of campus as well as the electric and gas consumption for air conditioning use was measured. Web cameras were installed in several rooms in one section of the campus to record lighting and air conditioning use data. The data was analyzed to reveal a correlation between hourly outdoor temperature and hourly electric consumption, with a stronger correlation between hourly outdoor temperature and hourly electric consumption for air conditioning. [ABSTRACT FROM AUTHOR]

Model predictive control (MPC) strategies can be applied to the coordination of energy hubs to reduce their energy consumption. Despite the effectiveness of these techniques, their potential for energy savings are potentially underutilized due to the fact that energy demands are often assumed to be fixed quantities rather than controlled dynamic variables. The joint optimization of energy hubs and buildings' energy management systems can result in higher energy savings. This paper investigates how different MPC strategies perform on energy management systems in buildings and energy hubs. We first discuss two MPC approaches; centralized and decentralized. While the centralized control strategy offers optimal performance, its implementation is computationally prohibitive and raises privacy concerns. On the other hand, the decentralized control approach, which offers ease of implementation, displays significantly lower performance. We propose a third strategy, distributed control based on dual decomposition, which has the advantages of both approaches. Numerical case studies and comparisons demonstrate that the performance of distributed control is close to the performance of the centralized case, while maintaining a significantly lower computational burden, especially in large-scale scenarios with many agents. Finally, we validate and verify the reliability of the proposed method through an experiment on a full-scale energy hub system in the NEST demonstrator in Dübendorf, Switzerland. [ABSTRACT FROM AUTHOR]

Abstract: The energy policy about energy performance of buildings, including minimum energy requirements and energy performance certificate (EPC), is applied to new and existing buildings, especially in the case of energy retrofit. Among existing buildings, heritage buildings are a special case. Another problem is finding an evaluation and measurement tool for town energy consumption which is related to the age and the characteristics of existing buildings. This problem concerns both urban planning discipline and heritage buildings discipline. The introduction of EPC database in Emilia-Romagna legislation (a region located in the North-East of Italy) is an opportunity to perform studies and simulation, in addition to GIS networking elaboration. This paper deals with the case of Ferrara, an old town, in order to debate: [-] number and energy incidence of heritage buildings; [-] influence of typology factor for energy saving in heritage buildings; [-] use of GIS tools to refer EPC, energy class in order to suggest a zone energy indicator (ZEI) for measuring the city and the old town. [Copyright &y& Elsevier]

Abstract: In this paper we undertake a comprehensive study to meet the building heating/cooling and power demand through a sustainable operation. We integrated polymer electrolyte membrane fuel cell (PEMFC) system and triple effect absorption refrigeration system (TEARS) for space cooling/heating and water heating applications in buildings. The analysis is carried out to observe the effects of different operating conditions on the efficiency of the fuel cell, output of the fuel cell and TEARS, and the utilization factor of the system. It is found that the efficiency, the utilization factor, and change in temperature of hot water increases from 36% to 48.8%, 49% to 86%, and 14K to 23K, respectively when the temperature of the cell is increased for different cooling loads and membrane thicknesses. In addition, the increase in membrane thickness affected the efficiency, the utilization factor, and change in temperature of hot water in a negative way and they were found to be decreasing from 47.3% to 42%, 85% to 49%, and 23K to 12K, respectively for different cooling loads. The water supplied to the house is obtained from a geothermal water source which makes the system more sustainable. [Copyright &y& Elsevier]

Abstract: Energy use in the built environment represents a large part of total energy use in Sweden and is one important sector where energy conservation needs to be significantly improved in order to meet the national implementation of the European goals. One key question that needs to be investigated in relation to these goals is the performance and implementation of passive or low-energy houses. This paper presents results and an evaluation of a newly built house in an area with passive houses in Linköping, Sweden. Nine passive houses were built with the aim to be energy efficient, with an annual space heating demand of 21kWh/m2, and at the same time to have the same visual appearance as any other building in the surrounding area. This study evaluates the energy performance of a residential area with low-energy buildings based on Building Energy Simulation (BES) (IDA ICE 4), and measurements from the real object. Both annual and hourly validation is performed using room by room modeling and internal heat gains. A novel approach to internal heat gain modeling is presented using time-use data (TUD). The results show possible improvements in the design, the building envelope and in the heating control. [Copyright &y& Elsevier]

Abstract: As a regular data-driven method, Artificial Neural Networks (ANNs) are popular in building energy prediction. In this paper, an alternative approach, namely, hybrid genetic algorithm-adaptive network-based fuzzy inference system (GA-ANFIS) is presented. In this model, GA optimizes the subtractive clustering’s radiuses which help form the rule base, and ANFIS adjusts the premise and consequent parameters to optimize the forecasting performance. a hierarchical structure of ANFIS is also suggested to solve the probably curse-of-dimensionality problem. The performance of the proposed model is compared with ANN using two different data sets, which are collected from the Energy Prediction Shootout I contest and a library building located in Zhejiang University, China. Results show that the hybrid GA-ANFIS model has better performance than ANN in term of prediction accuracy. The proposed model also has the same scale of modeling time as ANN if parameters in GA procedure are carefully selected. It can be regarded as an alternative method in building energy prediction. [Copyright &y& Elsevier]

Abstract: The concern on climate change leads to growing demand for minimization of energy use. As building is one of the largest energy consuming sectors, it is essential to study the impact of climate change on building energy performance. In this regard, building energy simulation software is a useful tool. A set of appropriate typical weather files is one of the key factors towards successful building energy simulation. This paper reports the work of developing a set of weather data files for subtropical Hong Kong, taking into the effect of future climate change. Projected monthly mean climate changes from a selected General Circulation Model for three future periods under two emission scenarios were integrated into an existing typical meteorological year weather file by a morphing method. Through this work, six sets of future weather files for subtropical Hong Kong were produced. A typical office building and a residential flat were modeled using building simulation program EnergyPlus. Hourly building energy simulations were carried out. The simulated results indicate that there will be substantial increase in A/C energy consumption under the impact of future climate change, ranging from 2.6% to 14.3% and from 3.7% to 24% for office building and residential flat, respectively. [Copyright &y& Elsevier]

Abstract: The present paper suggests a procedure for identification of suitable models for the heat dynamics of a building. Such a procedure for model identification is essential for better usage of readings from smart meters, which is expected to be installed in almost all buildings in the coming years. The models can be used for different purposes, e.g. control of the indoor climate, forecasting of energy consumption, and for accurate description of energy performance of the building. Grey-box models based on prior physical knowledge and data-driven modelling are applied. This facilitates insight into otherwise hidden information about the physical properties of the building. A hierarchy of models of increasing complexity is formulated based on prior physical knowledge and a forward selection strategy is suggested enabling the modeller to iteratively select suitable models of increasing complexity. The performance of the models is compared using likelihood ratio tests, and they are validated using a combination of appropriate statistics and physical interpretation of the results. A case study is described in which a suitable model is sought after for a single storey 120m2 building. The result is a set of different models of increasing complexity, with which building characteristics, such as: thermal conductivity, heat capacity of different parts, and window area, are estimated. [Copyright &y& Elsevier]

Abstract: This paper addresses the application of Energy Efficiency Rating Technical Quality Regulations for Commercial, Service and Government Buildings – RTQ-C in order to ascertain whether the conventional construction system for buildings complies with these requirements. Additionally, it investigates the contribution of labeling to reducing electricity consumption by the building. To do so, the RTQ-C was applied to two buildings in order to calculate the efficiency levels of their envelopes and possible alterations are proposed for upgrading the envelope performance where pertinent. It is noted that conventional buildings adopting measures such as painting the walls and roof white, in addition to using smoked glass, are sufficient to bring the rating up to an A grade. As no specific concern was noted in the architectural designs for the buildings studied, making use of design strategies that minimize the use of electricity in these buildings, the findings of these case studies may well indicate that the RTQ-C has adopted technical requirements that are not particularly stringent. Consequently, it is believed that these requirements should be reviewed during a second stage, in order to make them more restrictive and attain further improvements in the constructed environment with better energy efficiency for buildings. [Copyright &y& Elsevier]

Abstract: This paper presents a novel method for evaluating facilities in regard to their designed intelligence. Facilities intelligence is defined as the designed capacity of a facility to acquire and process data and information to perform its adaptability to lifecycle circumstance changes in terms of people''s requirements of wellbeing and energy efficiency. This definition is then formulated to quantify the Index of Facilities Intelligence, the level of facilities intelligence, and the reliability of facilities evaluation. STEEP (social, technical, economic, environmental, and political) criteria and their sub-criteria are used to set up an ANP (analytic network process) model, and ANP result such as synthesized priority weights is then used to calculate those parameters related to facilities intelligence. An experimental case study is given to prove the effectiveness of applying the proposed method to evaluate the intelligence of facilities in practice. [Copyright &y& Elsevier]

Abstract: It is well known that it is necessary to insulate the buildings to decrease the thermal demand and to decrease the use of heating and cooling. Due to the high cost of fossil fuels and to the necessity to reduce CO2 emissions, and also due to the new building regulations more attention is paid to the insulation of buildings. Different insulation materials are available in the market. Usually, they are compared by their thermal conductivity and with theoretical calculations, but there are no experimental comparisons available, where the behavior of such insulation materials in a building is compared over time. This is why the authors started a comparison of three typical insulation materials, polyurethane, polystyrene, and mineral wool. For this purpose, four house-like cubicles were constructed (with a size of 2.4m×2.4m×2.4m) and their thermal performance throughout the time was measured. The cubicles were built under a conventional Mediterranean construction system, differing only in the insulation material used. During 2008 and the first months of 2009 the performance of these cubicles was evaluated, and the results are presented in this paper. [Copyright &y& Elsevier]

Abstract: There is an obvious and indisputable need for an increase in the efficiency of energy utilisation in buildings and in the energy supply system within communities. Heating, cooling and lighting appliances in buildings account for more than one third of the world''s primary energy demand. In turn, building stock is a major contributor to energy-related environmental problems and CO2 emissions. There are great potentials to be obtained through a more efficient supply of energy and rational use of energy in buildings. An optimisation of the exergy flows in buildings and related supply structures, similar to other thermodynamic systems such as power stations, can help in identifying the potential of increasing efficiency in energy utilisation. Through analyses, it can be shown that calculations based on the energy conservation and primary energy concept alone are inadequate for gaining a full understanding of all important aspects of energy utilisation processes. The high potential for a further increase in the efficiency of; for example, boilers, cannot be quantified exclusively by performing energy analyses—the energy efficiency is close to 100%; however, this potential can be demonstrated by using an exergy analysis, whereby the exergy efficiency of a common gas boiler is about 8%. It is necessary to work out new and more efficient ways to supply energy to satisfy the demand for energy services. This paper outlines the international co-operative work in the general framework of the International Energy Agency (IEA), the ECBCS Annex 49 “Low Exergy Systems for High Performance Buildings and Communities” [Annex 49, Energy Conservation in Buildings and Community Systems—Low Exergy Systems for High Performance Buildings and Communities, homepage: http://www.annex49.com, 2007]. [Copyright &y& Elsevier]

Abstract: In this paper we present an algorithm for calculating the reference temperature in the rooms of a building. The algorithm works in such a way as to properly reduce the reference temperature in the rooms when they are not occupied, and at the correct start time, before the rooms are occupied, recover the reference temperature back to the defined value. The algorithm is tested in six rooms of a simulated hotel building using the well-known TRNSYS software. Different occupancy regimes are considered in the various rooms, and simulations are performed for a period of 1 year using the weather data of the town of Portorož, Slovenia. The results obtained with the proposed algorithm are compared to the results achieved with a constant reference temperature setting. The comparison is made with regard to the energy consumed for the heating and cooling of the rooms, and taking account of the deviations from the allowed temperature rise time. In the rooms where the occupancy is not known in advance similar results can be obtained with the proposed algorithm as with the constant reference setting. However, in the rooms where the occupancy is known in advance, desired level of guest comfort can be preserved with the proposed algorithm with an approximately 10% lower energy consumption for the heating and cooling of the rooms than with the constant reference recovery time setting. [Copyright &y& Elsevier]

Abstract: The energy sector worldwide faces evidently significant challenges that everyday become even more acute. Innovative technologies and energy efficiency measures are nowadays well known and widely spread, and the main issue is to identify those that will be proven to be the more effective and reliable in the long term. With such a variety of proposed measures, the decision maker has to compensate environmental, energy, financial and social factors in order to reach the best possible solution that will ensure the maximization of the energy efficiency of a building satisfying at the same time the building''s final user/occupant/owner needs. This paper investigates the feasibility of the application of multi-objective optimization techniques to the problem of the improvement of the energy efficiency in buildings, so that the maximum possible number of alternative solutions and energy efficiency measures may be considered. It further shows that no optimal solution exists for this problem due to the competitiveness of the involved decision criteria. A simple example is used to identify the potential strengths and weaknesses of the proposed approach, and highlight potential problems that may arise. [Copyright &y& Elsevier]

Abstract: Recent ecological and political developments have created an increased focus on sustainable energy sources. The purpose of this paper is to examine a passive ventilation device, the windvent, and evaluate its potential against current British Standards BS5952:1991 [British Standards, Ventilation principles and designing for natural ventilation, BS5925:1991 (1991)] recommended fresh air delivery rates. The results provide useful information for both engineers and architects when examining ways to reduce new and existing buildings running costs, and conform to new legislation. Numerical analysis is carried out using a commercial Computational Fluid Dynamics (CFD) code, to investigate the effect of various external wind velocities (1–5m/s) and directions (concurrent and counter current) on the device performance. The results show that the windvent is capable of providing recommended rates of fresh air supply even at relatively low incident wind velocities. The performance indications show that the device warrants further analysis and provides a sustainable alternative ventilation system. [Copyright &y& Elsevier]

Abstract: This paper reports on an analytical investigation into the energy saving potential associated with modified comfort limits in transitional spaces in buildings. Such spaces may not require the same high level and close environmental control of more fully occupied spaces and thus a wider variation in conditions and interpretation of thermal comfort may be permitted. Estimations are made of energy saving potential based upon typical floor area proportions utilised for transition spaces of various types in office/commercial buildings. The data are combined with suggested norms for comfort expectation that have wider temperature limits than for normally occupied office zones. The method has been applied to a series of building types situated in the climate of the East Pennines area of the UK using a thermal analysis tool. The results show that useful energy savings (particularly for heating) are possible by allowing for a modest (and realistic) relaxation of prescribed comfort standards in transition spaces. Further work is now required to confirm the limits and assess energy saving in practice. [Copyright &y& Elsevier]

Abstract: The existing buildings stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive on the energy performance of buildings (EPBD), which has come to effect on 4 January 2006. The energy performance assessment for existing dwellings (EPA-ED) is a new methodology supported by software, developed in the framework of a European project that focuses on energy related issues for existing residential buildings, in line with the EPBD. This paper presents an overview of the method and software that can be used to perform building energy audits and assess buildings in a uniform way, perform demand and savings calculations, provide owners with specific advice for measures to improve energy performance, issue an energy performance certificate for existing buildings, and include some representative results from the pilot studies performed in several European countries. Also the sister-method EPA-NR, on non-residential buildings, currently under construction, is introduced. [Copyright &y& Elsevier]

Abstract: An energy cost allocation system records the energy consumption of a building and divides the overall energy costs between the flats. Because the indoor temperatures of rooms are usually not equal, static heat flows between flats cannot be avoided. Hence, in order to ensure fair energy costs per flat the system should be able to determine the static heat flows, preferably without utilising in situ measurements. This paper presents a new method for estimating static heat flows between neighbouring rooms. The approach is theoretical, focusing only on heat transfer issues. Energy cost allocation is not considered. The approach is based on the parametric model describing thermal behaviour of an occupied space. The model is created for each room of a building. Parameter values are identified using real-time measurements collected by a building automation system from each room and its environment. The tuning of parameters takes a few days using a 15-min sampling time. A prerequisite for successful system identification is the overall control of the room temperatures. All test runs are performed in a simulated office hotel using the TRNSYS simulation program. The results are encouraging, but further research is needed, especially in a real building environment. [Copyright &y& Elsevier]

The methodology for baseline building energy consumption is well established for energy saving calculation in the temperate zone both for performance-based energy retrofitting contracts and measurement and verification (M&V) projects. In most cases, statistical regression models based on utility bills and outdoor dry-bulb temperature have been applied to baseline monthly and annual whole building energy use. This paper presents a holistic utility bills analysis method for baseline whole building energy consumption in the tropical region. Six commercial buildings in Singapore were selected for case studies. Correlationships between the climate data, which are monthly mean outdoor dry-bulb temperature (T0), relative humidity (RH) and global solar radiation (GSR), and whole building energy consumption are derived. A deep prediction study based monthly mean outdoor dry-bulb temperature (T0) and whole building energy consumption is stated. The result shows that variations of the energy consumption in most of these buildings are contributed by T0 and can be well predicted at 90% confidence level only with it. The analysis of such kind of model is especially useful for building managers, owners and ESCOs to track and baseline energy use during pre-retrofit and post-retrofit periods in the tropical condition. [Copyright &y& Elsevier]

Almost in all the major cities in Asian countries, residential buildings are characterized with high-rise and high density. Under this circumstance, achieving comfortable and healthy indoor environment with minimized energy consumption becomes a very challenging engineering and societal issue. While the wide use of air-conditioning helped to improve thermal comfort, health problems associated with poor indoor air qualities have appeared more frequently. The increased energy consumption is also a great concern in view of its impact on the energy economics of the region. Drawn from some of the onsite measurements and survey, and also the author’s personal observation, some of the key issues are discussed in this paper. [Copyright &y& Elsevier]

In summer natural ventilation is the most effective passive cooling system of the Mediterranean area. The correct exposure of the buildings and of the urban morphology to prevailing winds allows reducing the cooling loads also in non-bioclimatic buildings, without any cost. This paper points out the cooling capacity and the possibilities of energy saving offered by a correct natural ventilation by means of the simulation of a non-bioclimatic building, that is, a building having common characteristics as for construction materials and technologies. [Copyright &y& Elsevier]

The objective of this work is to evaluate the possibility of ensuring indoor temperature and relative humidity in an acceptable range by controlling heating and ventilation associated with minimising the energy consumption or cost by the use of a numerical simulation program. An acceptable indoor range means that indoor temperature is 20 °C with small fluctuation and relative humidity is in the range of 20–70%. A simple heating and ventilation control regulation is proposed. Simulation examples are conducted for different types of buildings based on energy consumption or cost factor. Simulations demonstrate that the indoor condition is much more improved and significant energy consumption or cost can be reduced by using the control regulation developed in this paper. [Copyright &y& Elsevier]

The selection of the type of glazing as well as its proportion to the total wall area are very important towards achieving a desirable indoor environment. This paper uses a dynamic thermal-circuit zone model to study the influence of the glazed openings percentage (GOP) and type of glazing on the maximum and minimum indoor temperatures, during and after solar hours. The model comprises of four major structural heat-flow paths, corresponding to the external and internal walls, glazing and horizontal slabs. The simulation is performed for winter and summer seasons and for a zone with and without a power plant, with an external wall having south orientation. In the latter case, the optimum GOP leading to the minimum energy consumption is determined. The zone formation comprises masonry walls with insulation in the center plane, concrete horizontal slabs with and without insulation and three different types of glazing (double, double with low emissivity (low-ϵ) coating and double with reflective film). As GOP varies, computer results show how the type of glazing and the insulation of the slabs affect the indoor zone temperatures and energy efficiency. [Copyright &y& Elsevier]

• Telework impacts transportation, building, and Internet-related energy and emissions. • Telework's environmental impact is highly dependent on contextual details. • The majority of studies indicate telework decreases energy use, with some exceptions. • Rebound effects tend to significantly offset and even exceed energy savings. • Existing research methods tend to be simple, leaving room for significant improvement. Teleworking has been widely perceived as a more sustainable mode of working for knowledge workers compared to the status quo of commuting to centralized offices because of its reduced dependency on transportation and centralized office space. However, the situation is far more complex than would appear on the surface, when the scope is expanded to include home office energy use, the Internet, long-term consumer choices, and other so-called rebound effects. Few studies have quantified home, office, transportation, and communications energy or GHG emissions implications of telecommuting simultaneously. To make progress in answering the question of whether telecommuting results in less energy use and greenhouse gas emissions than conventional centralized office working, this paper reviews results and research methods of primarily quantitative studies of any and all four domains that consider operating energy and/or greenhouse gas emissions. The results ultimately show that this problem is complex, and that current datasets and methods are generally inadequate for fully answering the research question. While most studies indicate some benefit, several suggest teleworking increases energy use – even for the domain that is thought to benefit most: transportation. [ABSTRACT FROM AUTHOR]

The aim of the present paper is to investigate the influence of electricity tariffs on energy flexibility in buildings and associated energy costs. A residential building located in Stuttgart, Germany, equipped with a hybrid heat pump which is coupled with a thermal energy storage unit and a gas boiler is used as a case study. A model predictive control algorithm is used to minimise the daily operational cost over a full heating season. Several demand response programs based on controlling the heat pump power consumption were tested and analysed by adopting different metrics capable of describing the flexibility potential and cost of demand response programs. Several tariff structures, including: real-time pricing, two-level day-night tariffs and critical-peak pricing with both fixed and variable feed-in price components, were investigated. The results show that the building can provide up to 1370 kWh e of energy flexibility over the heating season with an average specific (marginal) costs of between €0.024–0.035 per kWh e of flexibility provided. The demand response programs lead to higher utilisation of thermal energy storage along with increased boiler consumption, by up to 17.1% and 12.1%, respectively in case of maximum demand response intensity. This in turn leads to a higher overall primary energy consumption of between 1.6% and 9.1% depending on demand response intensity. Typically, real-time pricing is the most favourable tariff structure, capable of offering the greatest energy flexibility with lowest associated electricity costs. [ABSTRACT FROM AUTHOR]

• A gamification platform to foster energy efficient behaviors in office buildings. • The gamification platform is a mobile application with interactive dashboards. • The mobile gamification platform was demonstrated in an office building. • The demonstration results suggest electricity savings of 20%. Office buildings consume a significant amount of energy that can be reduced through behavioral change. Gamification offers the means to influence the energy consumption related to the activities of the office users. This paper presents a new mobile gamification platform to foster the adoption of energy efficient behaviors in office buildings. The gamification platform is a mobile application with multiple types of dashboards, such as (1) an information dashboard to increase the awareness of the users about their energy consumption and footprint, (2) a gaming dashboard to engage users in real-time energy efficiency competitions, (3) a leaderboard to promote peer competition and comparison, and (4) a message dashboard to send tailor-made messages about energy efficiency opportunities. The engagement and gamification strategies embedded in these dashboards exploit economic, environmental, and social motivations to stimulate office users to adopt energy efficient behaviors without compromising their comfort and autonomy levels. The gamification platform was demonstrated in an office building environment. The results suggest electricity savings of 20%. [ABSTRACT FROM AUTHOR]