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Much research has been focused on maintaining stable humidity conditions in buildings housing heritage collections while reducing energy use. Moisture buffering by collections themselves can have a marked effect on the stabilisation of relative humidity (RH), the key parameter for preservation. Modelling of moisture transport using COMSOL Multiphysics was applied to transform three-dimensional paper and wooden objects into their one-dimensional representations, without changing the moisture uptake and release characteristics. The results were coupled to the modelling of indoor microclimate and energy consumption in collection storage spaces with the use of WUFI ® Plus software. The study revealed the crucial impact of air exchange rate of the building on the stability of indoor RH and the humidification and dehumidification loads required to maintain it. In the adequately air-tight library store, a sizeable paper collection was found to reduce the RH fluctuations from ±9% to ±6% around the yearly average and the energy consumption due to the humidification and dehumidification load by 38% when compared with the empty space, for a high-quality climate control scenario. In turn, a wooden collection, occupying a realistic fraction of a museum store was not large enough to significantly narrow down the RH variations and reduce the energy consumption. [ABSTRACT FROM AUTHOR]

• Automatic MiC envelopes and layout generation by a novel SSG-MOO method. • Multi-objective optimization formulation for passive MiC design. • A pilot MiC study in Hong Kong produced 5 selected Pareto optima out of 625. • Up to 0.42% energy savings and 9.71% spatial daylight autonomy improvement against the baseline. • A multi-level analysis of results and design strategies for practitioners. Modular-integrated Construction (MiC) is an emerging construction technique promoted in the building sector for high productivity and low waste emission in the construction phase; yet, the standardized modules also bring new challenges, such as balancing passive energy efficiency and spatial daylight autonomy, to the operational phase. This paper proposes a Symmetric Skeleton Grammar-based Multi-Objective Optimization (SSG-MOO) method to formulate parametric MiC envelopes and detailed layout, with the two objective functions being energy efficiency and interior daylight performance in the operational phase. Pareto optima of the SSG-MOO, computed by the Non-dominated Sorting Genetic Algorithm II, are generally verified and analyzed in three levels, i.e., MOO's solution space, SSG layout, and MiC design parameters. A case study of MiC residential building in Hong Kong demonstrated the SSG-MOO method through five new passive MiC designs (i.e., spatial reorganization of three architectural modules, and parameter tuning of the envelops and corridors), achieving up to 0.42% energy savings and 9.71% spatial daylight autonomy improvement compared to the baseline design. The contribution of this paper is two-fold, including a novel and sound SSG-MOO formulation for parametric MiC designs, and offering time-efficient and evidence-based design tactics for MiC designers and industrial practitioners to push boundaries of MiC. [ABSTRACT FROM AUTHOR]

• Renewable energy assessment methods used in 12 GBRSs are analysed and compared. • Methods used in green neighbourhood rating system are also introduced. • Evaluation way, renewable energy types, building characteristics, etc. are analyzed. • The effects by using different methods in one building are analysed. • Suggestions are provided to improve the renewable energy assessment. Green buildings and neighborhoods can help mitigate impacts of buildings on the environment, society and economy. Many rating systems or tools have been developed worldwide to assess and certificate green buildings or green neighborhoods. Renewable energy plays an important role in achieving green buildings/neighborhoods or zero energy buildings/neighborhoods by reducing fuel consumption and pollution emissions. However, substantial differences exist in assessing or quantifying the renewable energy in green building/neighborhood rating systems. This paper therefore provides a comprehensive review on renewable energy assessment methods adopted in green building/neighborhood rating systems, which would be very helpful to understand and then improve the rating systems. These methods are analyzed and discussed regarding to the calculation way, involved renewable energy types, building characteristics and energy conversion. Then a case study is conducted to quantitatively illustrate the difference of typical renewable energy assessment. Suggestions are summarized to improve the assessment methods. This paper will help investors, users and policy makers understand the rating systems more thoroughly and promote the development of green buildings and green neighborhoods. [ABSTRACT FROM AUTHOR]

Abstract In 2011, the Danish government published an energy strategy for Denmark where one of the main targets are that Denmark should be a fossil-free society by 2050. Calculations show, that in order to reach this goal it is necessary to reduce the energy consumption of the existing building stock by 50% on average. Since a 50% reduction is obviously not possible for all buildings, those that can should aim for a so-called "deep energy renovation", i.e. reducing the energy consumption to a level corresponding to that of new buildings or even more. This paper describes two case studies where multi-story apartment buildings have undergone deep energy renovation. "Traneparken" where the expected energy use after renovation aimed at a level corresponding to that of a new building according to the Danish Building Regulations from 2015. "Sems Have" where the aim was to go even further and meet the requirements expected for new buildings in 2020, i.e. corresponding to the Danish "nearly zero energy"-definition according to the EPBD. The paper reports on calculations and measurements of energy savings, the economy of the projects and looks at the added benefits or co-benefits that residents, housing association and society in general have achieved in addition to significant energy savings. [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]

Buildings are responsible for about 92% of the total energy end-use in Hong Kong, of which above 70% is from the commercial sector. Most of the buildings in Hong Kong are high-rise, and approximately 15% of the total building stock is commercial buildings. Despite the considerable improvement in the understanding of the life cycle energy use of office buildings, there is still a lack of research into the life cycle energy demand of high-rise office buildings. Such knowledge is however essential for facilitating building energy conservation in the high-rise urban environment. The aim of this paper is to investigate the life cycle energy use of high-rise office buildings. The research was carried out through a critical literature review and case studies of ten real-life high-rise office buildings in Hong Kong. Results show that the life cycle energy consumption is 51.78–73.64 GJ/m 2 over the 50-year study period. Building operation consumes 78–89% and the rest (i.e. 11–22%) is taken by the embodied energy. Despite the distinction in terms of the amount of embodied energy between high-rise buildings and low-rise counterparts, no clear correlation is found between building height and embodied energy intensity. Moreover, energy use for material manufacturing and transport should be prioritised in reducing the embodied energy, of which the transport energy needs to be taken into extra consideration for the case of Hong Kong. The findings should inform construction industry participants of the significant potential in reducing the embodied energy of high-rise office buildings. The paper profiles the life cycle energy use of high-rise office buildings and should be important for the policy formulation towards the holistic energy conservation in high-rise buildings over their lifespans. [ABSTRACT FROM AUTHOR]

There has been general recognition within the construction industry that there is a discrepancy between the amount of energy that buildings actually use and what designers considered that they should use. This phenomenon is termed “The Performance Gap” and is normally associated with new buildings. However, existing and older buildings contribute a greater amount of operational carbon. In response to the Performance Gap, CIBSE have developed the TM54 process which is aimed at improving energy estimates at design stage. This paper considers how the TM54 process can also be used to develop energy management procedures for existing buildings. The paper describes an exercise carried out for a university workshop building in which design energy use has been compared with the actual building energy use and standard benchmarks. Moreover, a sensitivity assessment has been carried out using different scenarios based on operation hours of building/equipment, boiler efficiency and impact of climate change. The analysis of these results showed high uncertainty in estimates of energy consumption. If carbon challenges are to be met then improved energy management techniques will require a more systematic approach so that facilities managers can identify energy streams and pinpoint problems, particularly where they have assumed responsibility for existing buildings which often have a legacy of poorly metered fuel consumption. [ABSTRACT FROM AUTHOR]

• A data-informed building energy management (DiBEM) framework was proposed. • It was demonstrated in an office/laboratory building with two-years' experimental data. • The impacts of energy efficient interventions were quantified through data-driven models. • The energy use intensity was reduced from 54.1 kWh/m2 to 42.8 kWh/m2. To support building operations in reaching ultra-low energy targets, this paper proposes a data-informed building energy management (DiBEM) framework to improve energy efficiency systematically and continuously at the operation stage. Specifically, it has two key features including data-informed energy-saving potential identification and data-driven model-based energy savings evaluation. The paper demonstrates the proposed DiBEM with a detailed case study of an office and living laboratory building located in Cambridge, Massachusetts called HouseZero. It focuses on revealing the performance of the energy-efficient interventions from two-years' building performance monitoring data, as well as evaluating energy savings from the interventions based on the data-driven approach. With Year 1 as baseline, several interventions are proposed for Year 2 including improvements to controls and operation settings, encouragement of occupants' behavior for energy savings, and hardware retrofitting. These were deployed to heating/cooling, domestic hot water, lighting, plug and other loads, and photovoltaic (PV) systems. To quantify the impacts of different interventions on energy end uses, several data-driven models are developed. These models utilize linear regression, condition model, and machine learning techniques. Consequently, the heating/cooling energy consumption that was already ultra-low in Year 1 (12.8 kWh/m2) is further reduced to 9.7 kWh/m2 in Year 2, while the indoor thermal environment is well maintained. The domestic hot water energy is reduced from 2.3 kWh/m2 to 1.2 kWh/m2. The lighting energy is only increased from 0.3 kWh/m2 in pandemic operations without occupancy in Year 1 to 0.8 kWh/m2 in partial normal operations in Year 2, while the indoor illuminance level meets occupants' requirements. Combined with other relatively constant loads and the reduction of plug and other loads due to COVID building operation restrictions, the total energy use intensity is thereby reduced from 54.1 kWh/m2 to 42.8 kWh/m2, where 5.4 kWh/m2 of energy reduction for Year 2 is estimated to be contributed by the energy-efficient interventions. PV generation is 36.1 kWh/m2, with an increase of 1.4 kWh/m2 from a new inverter. In summary, this paper demonstrates the use of DiBEM through a detailed case study and long-term monitoring data as evidence to achieve ultra-low energy operations. [ABSTRACT FROM AUTHOR]

Facing the challage of energy conservation and emission reduction in the building sector, most energy saving strategies of central heating only focus on the performance improvement of building envelope, ignoring the impact of energy use behavior. This paper proposed a building energy conservation strategy based on energy use behavior analysis, which provides a perspective for in-depth exploration of building energy conservation. After investigating a typical university in the northern China, the energy use behaviors were characterized and two different DeST energy consumption models before or after considering energy use behavior were established. By comparing the results calculated by these two models, the impact of energy use behavior analysis on building energy consumption was quantitatively analyzed. The results show that the heating energy consumption and carbon emission can be reduced by 23.28% and 23% respectively through the proposed strategy based on energy use behavior. Therefore, the analysis of energy use behavior can provide a theoretical basis for heating operators to make decisions on energy supply regulation. With central cooling and heating further popularizing in the future, the research methodology of this paper has more extensive reference value for energy conservation and emission reduction strategies in the building sector. [ABSTRACT FROM AUTHOR]

• Obtaining the optimal interpolation method for adjacent sites. • Proposing the method for revising meteorological data at city scale. • Verifying the accuracy of the method by energy consumption simulation. In the development process of building energy conservation design, the correct provision of local Typical Meteorological Year (TMY) data is a prerequisite and basic work to evaluate building energy consumption, which directly affects the fine use of outdoor data for building energy conservation. Based on the recorded and observed data of meteorological stations in China, the acquisition and correction methods of TMY were studied by mathematical statistics and target searching, and the building energy consumption simulation of urban office buildings was conducted to verify the accuracy of the method, including:(1) Reviewed the generation method for TMY and the acquisition of data.(2) Based on the existing TMY data, the best spatial interpolation method of adjacent stations is studied by using the standard deviation method, and the selection method of the best number of stations on a large regional scale is given.(3) An improved method of urban environment TMY is proposed. The dry bulb temperature and relative humidity of the building site are corrected to generate TMY under Urban Heat Island (UHI) effect. The research in this paper improves the coverage and accuracy of urban TMY data and supplies basic research support for building energy-saving designs. [ABSTRACT FROM AUTHOR]

Highlights • The paper studies the impact of urban parks on reducing urban temperature. • Findings reveal that urban park construction reduces building energy consumption. • There is a limit distance to the reduction of energy consumption due to urban parks. • Change of urban characteristics due to park construction affects energy consumption. Abstract A change in the thermal environment of an urban area affects health, living conditions, and energy consumption. In urban planning, urban parks are one of the methods for improving the thermal environment and saving cooling energy. Urban park construction can mitigate temperature, but it also causes urban development by increasing local attractiveness. To achieve efficient energy saving through parks in urban planning, the purpose of this study is to investigate the relationship between building energy consumption and urban characteristics both before and after the construction of an urban park. This study targeted Seoul's Gyeongui line forest, which was recently converted into a linear park on the former railway as an urban regeneration project. We analyzed the relationship between energy consumption and urban characteristics using a regression model, focusing on the changes before and after the construction. In this study, urban characteristics include environment, building physical characteristics, and economic variables. The results show that the construction of the urban park reduced not only temperature but also building energy consumption. The energy reduction effect of the park was limited to a marginal distance. Meanwhile, the urban park construction caused land prices to rise and prompted new development, and this changed the urban characteristics of the area and affected energy consumption. Despite changes in urban characteristics, urban park planning is an effective methods of reducing the energy consumption involved in cooling urban areas. We recommend comprehensive consideration of the urban factors when making park policy to reduce urban temperature and energy consumption. [ABSTRACT FROM AUTHOR]

Abstract: Building energy simulations are key to studying energy efficiency in buildings. The state-of-the art building energy simulation tools requires a high level of multi disciplinary domain expertise from the user and many technical data inputs that curb the usability of such programs. In this paper an IT tool is presented, which has the capability of predicting a building''s energy utilization configuration based on the reported annual energy and a few non-technical inputs from the user; and correspondingly generates cost effective energy conservation measures for the intended savings. The approach first identifies the system variables that are critical to a building''s energy consumption and searches for the combination of these parameters that would give rise to the annual energy consumption as reported by the facility. Genetic algorithms are utilized to generate this database. A statistical fit is formulated between the system variables and the annual energy consumption from the database. Using this correlation, system configuration for the target energy efficiency is determined with corresponding energy conservation measures. A cost analysis is carried out to prescribe the most cost effective energy conservation measures. Competency of the tool is demonstrated in the paper through case studies on three geographies with different climate conditions. [Copyright &y& Elsevier]

Abstract: This paper reviews existing case studies and methods for calibrating whole building energy models to measured data. This research describes a systematic, evidence-based methodology for the calibration of these models. Under this methodology, parameter values in the final calibrated model reference the source of information used to make changes to the initial model. Thus, the final model is based solely on evidence. Version control software stores a complete record of the calibration process, and the evidence on which the final model is based. Future users can review the changes made throughout the calibration process along with the supporting evidence. In addition to the evidence-based methodology, this paper also describes a new zoning process that represents the real building more closely than the typical core and four perimeter zone approach. Though the methodology is intended to apply to detailed calibration studies with high resolution measured data, the primary aspects of the methodology (evidence-based approach, version control, and zone-typing) are independent of the available measured data. [Copyright &y& Elsevier]

Abstract: This paper takes an overall energy system approach to analysing the mismatch problem of zero energy and zero emission buildings (ZEBs). The mismatch arises from hourly differences in energy production and consumption at the building level and results in the need for exchange of electricity via the public grid even though the building has an annual net-exchange of zero. This paper argues that, when looked upon from the viewpoint of the overall electricity supply system, a mismatch can be both negative and positive. Moreover, there are often both an element of levelling out mismatches between individual buildings and an element of economy of scale. For these three reasons mismatches should be dealt with at the aggregated level and not at the individual level of each building. Instead, this paper suggests to compensate the mismatch of a building by increasing (or decreasing) the capacity of the energy production unit. Based on historical data for the electricity supply area in western Denmark, this paper makes a first attempt to quantify mismatch compensation factors. The results indicate that such compensation factors are a little below one for buildings with photovoltaics (PV) and a little above one for buildings with wind turbines. [Copyright &y& Elsevier]

Abstract: Building designers are often limited in their ability to reduce the environmental impact of buildings, due to a lack of information on the environmental performance of building components as well as inconsistencies in the way in which this information is derived. Whilst numerous tools exist to help facilitate the low-energy building design process, these typically require large investments of time and money that are often beyond those available within any particular project. This paper describes an approach for streamlining the design process to reduce building life cycle energy consumption. Building assemblies are ranked based on an assessment of the life cycle energy requirements associated with their use within a building. This facilitates early stage assessment, negating the need for a resolved design before the relative energy requirements of alternate design solutions are known. Previous work assessed the initial and recurring embodied energy as well as the operational energy requirements for heating and cooling associated with the use of a range of building assemblies, using a simplified house model. This paper presents a sensitivity analysis of variations to the floor area, shape and orientation of this model, to test the reliability and applicability of the ranking approach across a broad range of circumstances. It was found that these variations did not influence the ranked order of the assemblies in terms of their life cycle energy requirements. Thus, the ranking of assemblies appears to provide an appropriate approach for streamlining the selection of construction elements during the building design process. [Copyright &y& Elsevier]

Highlights • The urban energy budget can be reduced by retro-reflective (RR) directional cool materials. • The effect of ageing on RR tiles and paints performance is investigated. • The aged samples are characterized by spectrophotometric, directional and colorimetric analysis. • The cooling potential of new and aged RR materials is evaluated by an algorithm simulation. • The aged materials are performant: the urban cooling effect is preserved. Abstract Cool materials have been proposed for building applications given their potentialities in reducing building energy consumption, urban heat island effects, and global warming. Among cool materials, retro-reflective (RR) ones have been recently proposed for their ability to reflect backwards the incidental striking solar energy. This property is useful in densely urbanized areas, in urban canyons patterns, and in urban areas with buildings of different heights, because it avoids that the reflected energy contributes to the overheating of the neighbor buildings and structures. This study aims to predict the long-term performance of some RR tiles and paints intended for building applications. To this purpose, laboratory accelerated aging tests as described in the ASTM G154 were performed to determine the long-term material properties within a much shorter time than with outdoor weather aging. The samples show minimal changes in the reflectivity, directional reflection, and colorimetry. Finally, this paper shows that the RR character of the investigated materials and their urban cooling potential would be preserved. [ABSTRACT FROM AUTHOR]

In order to resolve the contradiction between the lack of building energy data and the need of more detailed information about energy performance, this paper presents a simplified building energy performance diagnosis method which can assess the energy performance from building level to system level with only limited information. Based on multiple-parameter regression between the whole building energy bills and outdoor weather data, the proposed diagnosis method uses the regression coefficients to identify the energy use of main systems (i.e., lighting-plug system and cooling/heating system), as well as other detailed information about physical properties of the building and cooling/heating system (i.e., cooling or heating load, the operation of cooling/heating system and the efficiency of cooling/heating system). One case study was conducted in an office building in China to test the application of this diagnosis method. In addition, the regression result of simulated energy consumption served as benchmark data to further diagnose the performance gap between the operation stage and the design stage and help locate the poor performance and key points of energy-saving. Finally, all diagnosis results have been verified by the performance data from advanced energy consumption monitoring system together with field surveys and measurements. [ABSTRACT FROM AUTHOR]

In Germany, policy-induced energy efficiency improvements typically aim at reducing primary energy consumption. Private households, on the contrary, pursue the maximization of wellbeing or, in microeconomics jargon, the maximization of utility of the occupants. There is a marked difference between upfront-calculated energy performance ratings (EPRs) and actual heat energy consumption (HEC). From an energy and environmental policy point of view, deviations of energy consumption from ex ante calculated EPRs is problematic, as it jeopardizes their usefulness for (prospective) homeowners, policy-makers and researchers relying on EPRs as a guidance. The EPR-HEC gaps reported are, apart from deviations from the mean aggregate values (i.e. heterogeneity), often attributed to anticipated or unanticipated behavioral effects. From an energy economist's point of view, energy rebound induced by lowered costs per unit of energy service due to increased energy efficiency is one explanation. The related literature almost entirely treats building-specific EPRs as universal standards, trying to explain the empirically observed discrepancies. In this paper, we investigate to what extent the current EPR scheme in place in Germany today can address behavioral issues. To this end, based on two different multi-family housing data sets for Germany and regression analysis, we empirically investigate the deviations between EPRs used in the regulatory norms and the HEC levels observed in reality. We find evidence that it is not necessarily the behavioral dimension, but rather the static and mostly technically guided calculation of the EPRs itself that accounts for the major part of the deviations. We conclude that there is indeed a need for further improvements in the field of EPR regulation and methodology. [ABSTRACT FROM AUTHOR]

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: This paper presents a study on energy performance of Singapore''s hotel buildings. Energy consumption data and other pertinent information were collected from 29 quality hotels through a national survey. Building features and operational characteristics contributing to the variations in hotel energy performance were discussed. The annual average total energy use intensity (EUI) in these hotels is 427kWh/m2. Electricity and gas are used in all sampled hotels, and some hotels also use diesel to power standby generator or hot water boiler. We also investigated relationships between electricity consumption and number of occupied rooms in individual hotels; the weak correlations found indicate it is necessary to improve energy management when occupancy rate is low. Besides, Pearson correlations between hotel energy use intensity and possible explanatory indicators revealed that three-star hotels differ from high class establishments in energy use. Worker density and years after the last major energy retrofit were also found to be highly correlated to hotel building energy use intensity. Also discussed in this paper is the effect of weather conditions on electricity consumption of the hotels. [Copyright &y& Elsevier]

Abstract: This paper presents the findings of a case study with building simulation using EnergyPlus dynamic thermal simulation software, in which wall insulation was varied together with cooling set-point temperature in a hot and dry climate of Botswana. Against the established norm that adding wall insulation reduces annual fuel consumption, it is shown in this paper that this is not always the case: there are instances where adding wall insulation directly increases annual fuel consumption. Initial cost of insulation aside, as the cooling set-point temperature is gradually increased, the building switches from an “insulation reduces cooling load” to an “insulation increases cooling load” behaviour. In other words, the well established knowledge that “the lower the u-value the better” gets overridden by “the higher the u-value the better”. We termed this a “point of thermal inflexion”. Simple graphical demonstration of the existence of this point is presented in the paper. According to the findings, design engineers and building economics related professionals who quantify investment on insulation can get disastrous results if they assume that all buildings behave pro-insulation since a building may behave anti-insulation. [Copyright &y& Elsevier]

Large scale smart meter deployments have resulted in popularization of sensor-based electricity forecasting which relies on historical sensor data to infer future energy consumption. Although those approaches have been very successful, they require significant quantities of historical data, often over extended periods of time, to train machine learning models and achieve accurate predictions. New buildings and buildings with newly installed meters have small historical datasets that are insufficient to create accurate predictions. Transfer learning methods have been proposed as a way to use cross-domain datasets to improve predictions. However, these methods do not consider the effects of seasonality within domains. Consequently, this paper proposes Hephaestus, a novel transfer learning method for cross-building energy forecasting based on time series multi-feature regression with seasonal and trend adjustment. This method enables energy prediction with merged data from similar buildings with different distributions and different seasonal profiles. Thus, it improves energy prediction accuracy for a new building with limited data by using datasets from other similar buildings. Hephaestus works in the pre- and post- processing phases and therefore can be used with any standard machine learning algorithm. The case study presented here demonstrates that the proposed approach can improve energy prediction for a school by 11.2% by using additional data from other schools. [ABSTRACT FROM AUTHOR]

This paper proposed a hybrid Logarithmic Mean Divisia Index (LMDI) model that decomposes the change of total energy consumption (TEC) in the building sector to three different dimensions: 1) key influencing effects that include area effect, structure effect, population intensity, value intensity, and energy intensity; 2) three phases that include material production, construction, and operation; and 3) geographically distributed regions. Then, the model was validated in China's building sector based on the data collected from 30 provinces during 2007–2015. The key findings show that: (1) the increased final energy consumption in the building industry accounted for 53.3% of that in China. (2) Building material production contributed the most (69.2%) to the energy changes, followed by building operation (29.6%) and construction (1.2%). (3) The change of TEC was attributed the most to the area effect (90.4%) and the energy intensity effect (42.4%). (4) Zhejiang, Jiangsu, Hubei, Hebei, Fujian and Shandong contributed the most (47%) to the increase of China's building energy use. These findings provide an insightful understanding of the building energy changes and also a quantifiable justification for making building-specific energy policies, which are discussed at the end of the study. [ABSTRACT FROM AUTHOR]

• A dynamic setting temperature that adapts to climate change was proposed. • The method was based on clothing adjustment behavior which adapts to thermal comfort. • The dynamic setting temperature had significant energy saving potential. • The dynamic setting temperature is useful for intelligent control of air-conditioner. Saving energy consumption of air-conditioning is essential to building energy conservation while satisfying the thermal comfort requirements of indoor environment. On the basis of human clothing adjustment behavior, a dynamic setting temperature (DST) that adapts to climate change was proposed in this paper, i.e. indoor air-conditioning setting temperature changes dynamically with outdoor air temperature; furthermore. A method was established to obtain the DST. The daily mean clothing insulation was predicted according to the historical temperature at first, then indoor thermal comfort temperature was calculated based on the variable clothing insulation, and finally the DST was determined. According to the value or range of predicted mean vote (0, -0.5~0.5, -1~+1) corresponding to the thermal comfort, three levels of DST were defined. The corresponding thermal acceptability rates were 95%, 90% and 73%, respectively. A simulation of DST was conducted in a public building in Changsha, China based on meteorological data of 2017. Three levels of DST ranges were obtained, varied from 20.1 to 27.8 °C in level I, 17.8 to 28.7 °C in level II and 15.4 to 29.7 °C in level III, respectively. The simulation results of operational air-conditioning energy consumption shows that the application of DST could save up to 65.5% of energy consumption compared with the traditional fixed setting temperature (FST), and the operational energy consumption decreased by 59.1% due to the application of level-III DST compared with level-I DST. Therefore, the DST proposed in this paper has significant energy saving potential while meeting the thermal comfort requirements. [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]

Photovoltaic (PV) façade on building envelope in an urban area can potentially produce clean electricity to meet the energy demand of the buildings and also provide weather protection. In order to assess the potential of PV application on building façade, energy generated and cost related to the PV installation, it must be analysed during the design process so that it can provide enough information to the designer, investor, and end user to make a decision in implementing renewable technologies. This paper focus on performance and financial evaluation using System Advisor Model (SAM) developed by National Renewable Energy Laboratory (NREL) to evaluate the potential of vertical photovoltaic façade system on a high-rise building in Malaysia based on 5 possible design scenario using Heterojunction Intrinsic Thin-film module (HIT-Si) with the nominal efficiency of 15.6%. The annual energy generated through the vertical photovoltaic system is between 400–700 MWh meanwhile roof system generate about 240MWh annually. The payback period for the vertical photovoltaic system in Malaysia is about 12 years. Although the installation of photovoltaic vertical façade in the tropical region can be quite challenging especially in urban area, but with proper studies and carefully design approach, its can open new opportunities in Malaysian built environment. [ABSTRACT FROM AUTHOR]

To reduce energy consumption in buildings, researchers have in the recent decade explored the potential of changing occupants’ energy consumption behaviors using eco-feedback technologies. Energy consumption behavior is a type of consumer behavior, which has been proven culture-specific in prior research. This paper aims to assess the impact of culture on the effectiveness of eco-feedback technologies in reshaping building occupants’ energy consumption behaviors, and to examine the mechanism of such impact. A total of 39 students from 10 different countries who shared four university dormitories were recruited in an experiment. A web-based eco-feedback system was developed in this study, and implemented in these dormitories. The eco-feedback system was responsible for sending weekly email reminders to students participating in the study and, upon their login, providing them with their detailed energy consumption data as well as those of their peers on a daily basis. Subsequent changes in the students’ energy consumption behaviors were analyzed, and correlated with their cultural background, which was assessed using a survey instrument designed based on Hofstede's cultural dimensions model. The experiment results showed that the mean and variance of changes in energy consumption, in response to the provision of eco-feedback information, differed significantly between participants from different countries. The results also showed that all cultural dimensions were statistically correlated to the effectiveness of the eco-feedback system, which explained how different aspects of culture could influence the energy consumption behaviors of building occupants. The results suggested that eco-feedback technologies should be tailored to specific cultural context to improve their effectiveness in building energy conservation. [ABSTRACT FROM AUTHOR]

Lack of information on energy consumption patterns of intermittent-operating escalators and unawareness of building owners of potential energy savings constitute the main obstacles for the penetration of energy-efficient escalator technology. Even though intermittent operation provides large energy savings in low passenger traffic, little research has been devoted to analyzing the composition of total energy consumption in these situations. This paper presents observations and data gathered during long-term energy measurements of an intermittent-operating escalator pair (one upwards, one downwards operating), equipped with reduced speed and stop & go modes, installed in a store in the Helsinki area. Energy consumption measurements were performed concurrently with people counting. The effect of passengers walking on the step band on daily energy consumption was calculated by relying on the people counting sensor data. Additional experiments were conducted by applying different masses to analyze the dependence of energy consumption on the carried load. Finally, the effect of intermittent operation, or speed control with stop & go functionality, on energy consumption was calculated for the escalator pair on the given site. The energy consumption is reduced up to 42% in the upwards running escalator and 52% in the downwards running escalator compared to a continuously running escalator with the same operating hours. The study concludes that the power consumption profiles of the intermittent-operating escalator pair highly depend on the characteristics of the people flow, mainly the consistency of the people flow. [ABSTRACT FROM AUTHOR]

• A kNN-BS method is proposed to repair lighting and plug energy data. • Using cross-validation method to select the optimal k. • Using 2-step data classification method to decide day type. • Achieved higher accuracy than traditional k NN. The public building energy consumption monitoring platforms (BECMPs) play an important role in building energy conservation and energy-related decision-making. However, problems such as data missing and data mutation are quite common that they impede the effectiveness of the BECMPs. Based on the k NN algorithm, this paper proposes a k NN-BS data repair algorithm with the characteristics of electricity consumption trends taken into consideration. After data classification and cleaning, the data of hourly lighting and plug power consumption of an office building of Dalian University of Technology is repaired using the k NN-BS algorithm. The cross-validation method is used to determine the optimal k value. The relative repair error of the total daily electricity consumption of k NN-BS is less than 4% for working days and less than 6% for non-working days. Compared with k NN, the average CVRMSE of the k NN-BS algorithm is reduced by 1.36%∼1.59% for working days and 5.49%∼8.17% for non-working days. The k NN-BS algorithm shows excellent stability and robustness compared with k NN, polynomial and BPNN, which makes it very suitable for practical use, especially in efficiency-demanding scenarios. The k NN-BS algorithm can effectively improve the quality of public building energy consumption monitoring data and provide a theoretical basis and technical means for solving data quality problems in the BECMPs. [ABSTRACT FROM AUTHOR]

Typically the effect of thermal bridges on the energy performance of buildings is taken into account by implementing an average U-value in 1D whole building energy simulation program, which is referred to as the equivalent U-value method. This treatment accounts for the effect of thermal bridges on the overall thermal transmittance of envelope details, while their thermal inertia effect is ignored. In this paper, the dynamic effect of balcony slab as thermal bridges on the energy performance of a high-rise residential building is investigated by comparing the annual space conditioning loads obtained by the equivalent U-value method to that obtained from 3D dynamic modeling of the balcony junctions implemented in WUFI Plus program. The simulation results show that the equivalent U-value method underestimates the annual heating loads by 2.8–4.4% for the building as-designed. With the increase of balcony portion and better insulated walls, the difference in annual space heating loads modeled using these two methods is increased to 8.6–15.2%. With the implementation of balcony thermal break the annual heating loads are reduced by 8.8–25.7% and the difference between these two modeling methods is also reduced to 1.9–11.5% for the cases investigated. [ABSTRACT FROM AUTHOR]

• The outdoor environment indexes are integrated by simulation and empirical method. • Quantitatively study the interaction between green space and water bodies. • The proper layout of landscape planning can reduce the building carbon emissions. The rapid urban construction has made urban residential buildings become the main source of greenhouse gas emissions. So far, the existing studies on the impact of urban micro-climate on building energy carbon emissions have shown that green space (GS) and water bodies (WB) play positive roles in regulating outdoor thermal environment and reducing building energy consumption. Accordingly, this paper quantitatively explores the influence of the interaction between GS and WB on reducing building carbon emissions. First, the building's micro-climate is simulated by Computational Fluid Dynamics (CFD) to obtain outdoor thermal environment indexes, which are used as inputting data to calculate carbon emissions by software HDY-SMAD. Then, we utilize Geographic Information System (GIS) and Remote Sensing (RS) techniques to explore the natural surroundings of buildings, such as GS and WB distribution within the administrative scope of Dujiangyan. Next, the linear regression method is applied to analyze the relationship between GS, WB, and residential building carbon emissions, in which the residential carbon emissions data is obtained by social survey. Finally, the simulation results are verified by empirical research method. The findings demonstrate that the GS and WB have area, accessibility and seasonal differences in regulating local thermal environment and reducing building carbon emissions, and the overall regulation ability of WB for micro-climate is more significant than that of GS. In addition, the ratio area between GS and WB has the most significant influence on reducing building carbon emissions when it is 3:1 in winter, but this optimal ratio is 1:2 in summer. These conclusions can provide benchmark information for landscape planning and building energy conservation in the future. [ABSTRACT FROM AUTHOR]

Radiant panels are known to be energy efficient sensible heating systems and a suitable fit for low-energy buildings. The main goal of this paper is to optimize the thermal insulation layers of house heated by using the radiant heating systems. This work is conducted to study four radiant systems: floor-heating system, wall-heating system, ceiling-heating system and newly developed floor-ceiling heating system located in a net-zero-energy house in Kragujevac, Serbia. The operation of these panels is simulated by software EnergyPlus. For the optimization of the optimal length of the thermal insulation software GenOpt is used. [ABSTRACT FROM AUTHOR]

Underfloor air distribution (UFAD) system, which is a relative new method of providing conditioned air and ventilation to the commercial buildings and data centers, is focused by researchers and designers for its potential advantages of better indoor thermal comfort (ITC) and indoor air quality (IAQ), layout flexibility, reduced life cycle costs, and energy saving. However, the application of UFAD system are still obstructed by the gap in the fundamental understanding of some new elements, such as the cooling load calculation, control of the thermal stratification, and evaluation of energy consumption. This paper reviews the current situation of UFAD technology, and the existing problems in recent researches are summarized. To improve the performance of UFAD system, several possible directions for the further studies are suggested. [ABSTRACT FROM AUTHOR]

Natural ventilation in residential buildings has a great potential for conserving energy and improving the health of occupants. This paper first presents a design strategy for optimizing natural ventilation in high-rise residential buildings in Chongqing, China, a region with unfavorably low wind speed. Through the use of CFD modeling, building orientation and spacing were adjusted, wind paths were created into internal zones, and two windows were constructed in each bedroom. The optimized design reduced the age of air to less than 6 min in 90% of the rooms, as compared to an age of greater than 30 min in 50% of the rooms in a conventional design. Natural ventilation was found to be effective in the Chongqing area with the optimized design. This investigation also measured the local age of air and air change rate in a building with the optimized design using a tracer-gas method. The measurements confirmed the reliability of the CFD results. [ABSTRACT FROM AUTHOR]

• Encouraging decision-makers to rely on residential tree allocation to transform urban canopy cover target strategies. • Understanding the hierarchy of tree planting parameters, based upon minimum tree number and maximum energy efficiency. • Guaranteed winter optimal residential tree arrangement in conserving annual energy demands, even with evergreen tree planting. • Demonstrating immediate green settings absence in the NatHERS assessment package. • Recommendation of five optimal tree allocation depending upon deep soil availabilities. Energy–efficient dwellings promote substantial urban energy conservation. Residential tree allocation, as an Urban Heat Island (UHI) mitigation strategy, stimulates climate responsivity, lowers Air Conditioner (AC) usage and heat distribution. This paper evaluates dwellings' response to residential tree planting parameters to assess the building–surround relationship. These parameters include tree type (evergreen or deciduous), volume (1–3 trees), Tree–Building distance (3 m or 5 m) in each cardinal and inter–cardinal azimuth. These planting configurations highlight dominant Australian urban planning policy and green open space restrictions. This study quantifies tree planting configuration models, utilising both typical and extreme weather data and a bi–seasonal approach, to arrive at an Optimal Residential Tree arrangement (ORTa). The simulation process tailors local weather data to assess tree impact upon the diurnal and nocturnal microclimate. The ORTa dependence upon orientation ensures correct deep soil levels and viable private backyard volume. The result demonstrates a high probability that deciduous trees save energy bi–seasonally. Across all aspects and weather conditions, ORTa allows for an evergreen tree addition to boost energy conservation without detrimental annual or bi–seasonal effects on building thermal response. Annual weather data indicates two deciduous trees are optimal. These trees would be located east or west at 3 m Tree–Building distance (T-B distance), north at 5 m T-B distance or south at 3 m minimum with the maximum depending upon neighbour's northerly aspect. In typical weather conditions, two deciduous tree arrangements lead to maximum 40% heating energy conservation from any potential ORTa in east, west or north. In addition, it provides 15% east or west cooling energy saving and 7% north. In extreme weather conditions, two tree arrangements provide 25% thermal heating conservation, in any aspect. During heatwaves easterly deciduous tree planting is optimal (18% energy conservation), followed by westerly (7%) and northerly (1%). This research recommends five ranked optimal tree arrangements depending on residential parcel deep soil availabilities. This optimisation result encourages decision–makers to appreciate residential green space and reanalyse future urban canopy cover target measurements. [ABSTRACT FROM AUTHOR]

Abstract: One of the primary reasons for the application of cool materials is their energy and associated environmental impact on the built environment. Cool materials are usually applied on the roof of buildings to reduce cooling energy demand. The relative benefits of this reduction depend on the construction of the building, external weather conditions and use of the building. This paper examines the impact from the application of a reflective paint on a flat roof in a naturally ventilated office building in the area of London, UK where the climate is moderate with high heating demand by buildings. The environmental conditions (internal/external air and surface temperatures) of the building were monitored before and after the application of the cool roof during the summer. It was found that internal temperatures were reduced after the application of the cool roof. The building was modelled using TRNSYS and the model was calibrated successfully using the measurements. A parametric analysis was carried out by varying the reflectivity and insulation of the roof and ventilation rate; the heating and cooling demand for a year was calculated using the Summer Design Year for London as the weather file. It was found that cooling demand is significantly reduced, heating demand is increased and the total energy savings vary between 1 and 8.5% relative to an albedo of 0.1 for the same conditions. In free floating (naturally ventilated) buildings summer comfort is improved but there is a penalty of increased heating energy during the winter. Thermal comfort can be improved by an average of 2.5°C (operative temperature difference for a change of 0.5 in albedo) but heating demand could be increased by 10% for a ventilation rate of 2 air changes per hour. The results indicate that in the case of temperate climates the type, operation and thermal characteristics of the building should be considered carefully to determine potential benefits of the application of cool roof technology. For the examined case-study, it was found that a roof reflectivity of 0.6–0.7 is the optimum value to achieve energy savings in a cooled office, improve summer internal thermal conditions in a non-cooled office (albeit with some heating energy penalty). It indicates that it is a suitable strategy for refurbishment of existing offices to improve energy efficiency or internal environmental conditions in the summer and should be considered in the design of new offices together with other passive energy efficient strategies. [Copyright &y& Elsevier]

Abstract: Chiller sequencing control plays an important role in achieving air-conditioning system energy efficiency since chillers usually account for major part of system overall energy consumption in commercial buildings. This paper compares and evaluates the in situ performances of three commonly used chiller sequencing control strategies. These three control strategies are operating online in parallel on a management and communication platform in a super high-rise building in Hong Kong. The comparison and evaluation focus on the perspectives of chiller switch number, electrical peak demand and overall energy consumption in one week. Meanwhile, the different impacts of two systematic errors (i.e. positive errors which cause direct measurement larger than true value and negative errors which cause measurement smaller than true value) on each control strategy are also analyzed. The performance comparison demonstrates that the strategy, using fused cooling load measurement, achieved the best performance. The applications of the online computed chiller maximum cooling capacity and the advanced data fusion technique, which removes the negative impacts of sensor measurement uncertainties, can significantly improve the performance of chiller sequencing control. [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: Because energy efficiency in buildings will be evaluated not only based upon heating demand, but also according to the primary energy demand, the ecological properties of the building materials for the whole assessment has become essential. The demand for green building materials is rising sharply, especially insulating materials from renewable resources. The application of natural materials has become increasingly important as a consequence of the increasing need to conserve energy, use natural materials, incorporate architecture and construction into sustainable development processes, and the recently promulgated discussions on appropriate disposal of used insulation materials such as polystyrene (EPS). Due to the fact that natural materials are more sensitive to moisture, decomposition factors such as temperature, material moisture content, attacks by microorganisms, and possible decomposition of the material or shorter durability, it is necessary to evaluate the degradation rate of built-in materials and also determine their real in situ hygrothermal properties according to their moisture content, and volume changes. This paper describes the results of a research project carried out at the Vienna University of Technology and Brno University of Technology. The objective is to use jute, flax, and hemp to develop a new insulating material from renewable resources with comparable building physics and mechanical properties to commonly used insulations materials. All input components are varied in the tests. The impact of moisture content changes in relation to the rate of change of other properties was the focus of the investigation. The tests results show that the correct combination of natural materials is absolutely comparable with convectional materials. [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: The cooling degree days concept is a tool to estimate and analyze weather related energy consumption in buildings, i.e. the cooling system electric energy consumption. The main problem with applying this method is that it disregards latent cooling loads. This paper deals with an approach for monitoring electric energy consumption due to cooling in buildings based on cooling degree days, which allows an estimation of latent loads. In addition to applying methods for determining base temperature to base humidity, a new technique is introduced, which is based on a significance test of the enthalpy latent days partial regression coefficient. Analogous to the performance line concept, the influence of latent loads can be presented in the form of a “performance surface” graph. The performance surface is a plot of electric energy consumption as a function of cooling degree days and latent enthalpy days. The above methods are tested on data sets consisting of electric energy consumption data obtained from two buildings and hourly meteorological data. [Copyright &y& Elsevier]

Abstract: To streamline the design of the energy efficient buildings, appropriate tools are needed to assess their energy performance taking into account the microclimatic context. Numerical simulation seems to be the most suitable issue, but none tool is dedicate to the direct evaluation of the microclimate influence on the building energy consumption. A complete solution could be to use both CFD and thermoradiative simulation tools complementary with the coupling technique perspective. This paper presents both a developed CFD–thermoradiative coupled simulation tool and a typical application on an urban fragment. The results lead to two kind of observations: [•] Integration of the thermal model of a building in the microclimatic simulation platform enable a quantitative evaluation of the building energy demand regarding different urban design scenarii (e.g. mineralized vs vegetated). [•] Different physical phenomena do not contribute as much in the energy balance and it is important to compute precisely each one to obtain the small scale microclimatic influence. [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: The evaluation of building energy consumption under typical meteorological conditions requires building energy profiles on an hourly basis. Computer simulations can be used to obtain this information, but generating simulations requires a significant amount of experience, time, and effort to enter detailed building parameters. This paper considers a simple methodology for using existing EnergyPlus benchmark building energy profiles to estimate the energy profiles of buildings with similar characteristics to a given benchmark model. The method utilizes the building monthly energy bills to scale a given benchmark building energy profile to approximate the real building energy profile. In particular, this study examines the robustness of the methodology considered with respect to the parameter discrepancies between a given building and the corresponding EnergyPlus benchmark model used to estimate its profile. Test buildings are defined by perturbing several combinations of the parameters defined in the benchmark building model. The test buildings examined are similar to the EnergyPlus, medium sized office, benchmark building in Baltimore, MD, and a total of 72 distinct test building configurations are examined. The analysis reveals that the methodology can significantly reduce the errors introduced by discrepancies from the EnergyPlus benchmark model. [Copyright &y& Elsevier]

Abstract: School buildings constitute a major part of the non-residential building stock, though due to their operational characteristics, they represent a low percentage of the overall energy balance of the building sector. Although health and productivity of pupils and teachers is strongly affected by the indoor environmental quality of their school, poor indoor air quality has been reported in published literature, even so for recently constructed school buildings. The same applies for the energy consumption, with large amounts of energy being wasted because no energy saving measures are applied for the operation of schools. This paper presents the outcome of a study on the energy performance of Hellenic school buildings. The general features of the contemporary building stock are presented along with the results from an energy survey in 135 Hellenic schools. The derived energy consumption benchmarks are compared with published literature. Finally, the energy performance and indoor environmental quality of a representative sample of schools in metropolitan Athens are assessed in a holistic approach to the “energy efficiency – thermal comfort – indoor air quality” dilemma. The IEQ assessment was based on an objective evaluation by monitoring crucial indoor conditions and a subjective occupant evaluation using standardized questionnaires. The potential of several energy conservation measures is evaluated in terms of energy savings and reduction of greenhouse gas emissions along with the related payback periods. [ABSTRACT FROM AUTHOR]

Abstract: Numerous computer programs are available to calculate the energy efficiency of buildings. Many are based on the use of a reference building to determine the degree of efficiency. However, this methodology presents a major constraint when assessing a building after construction and during the use stage. To assess the energy efficiency of buildings, this paper proposes new indices based on energy consumption during different periods; as well as other parameters of the buildings such as construction area, number of users, and air-conditioned volume. Results are presented as an application for various buildings on the campus of the Universidad Politécnica de Valencia. [ABSTRACT FROM AUTHOR]

Abstract: Looking to the EU''s 20/20/20 program, energy efficient retrofitting will be a key element in the 20% less primary energy in 2020 compared to business as usual. Within that context, field studies that put realizable efficiency in perspective are urgently needed. The dwelling evaluated was built in 1957. In those days energy efficiency was no concern. Houses got no insulation, ventilation was adventitious and heating systems scored badly. The retrofit started in the early eighties, stepwise as to follow the impact of separate measures on heating energy consumed. A solar boiler was installed in 2004. PV followed in 2009. The first 19 years a family of five inhabited the dwelling, then the parents only. Monitoring started in 1978. In the paper, predicted annual energy for space heating is compared with monitored result. The measured data, though showing a net decrease, consistently underscore predictions. Main reason is direct rebound. The benefits of the solar boiler and PV-panels are minimal compared to the energy avoided by better insulation, energy efficient windows, better air-tightness and upgraded ventilation and central heating. However, targeting passive house and zero energy quality is beyond optimal in terms of net present value and not doable in the dwelling. [Copyright &y& Elsevier]

Abstract: Green roofs are a passive cooling technique that stop incoming solar radiation from reaching the building structure below. Many studies have been conducted over the past 10 years to consider the potential building energy benefits of green roofs and shown that they can offer benefits in winter heating reduction as well as summer cooling. This paper reviews the current literature and highlights the situations in which the greatest building energy savings can be made. Older buildings with poor existing insulation are deemed to benefit most from a green roof as current building regulations require such high levels of insulation that green roofs are seen to hardly affect annual building energy consumption. As over half of the existing UK building stock was built before any roof insulation was required, it is older buildings that will benefit most from green roofs. The case for retrofitting existing buildings is therefore reviewed and it is found there is strong potential for green roof retrofit in the UK. [ABSTRACT FROM AUTHOR]

Abstract: The process of building labeling and certification in accordance to the provisions of the European Directive on the Energy Performance of Buildings (EPBD) constitutes a unique opportunity for collecting information on the characteristics of the building stock and its energy performance on a national and European level. Thus, there is a need to handle data from a large stock of buildings and to be able to analyse information and extract practical trends and benchmarks. Stakeholders and technical managers who oversee a number of buildings experience similar needs in order to collect, organize and monitor the energy performance of a large pool of buildings. To facilitate these efforts, a common evaluation database and complimentary software for its exploitation have been developed in the frame of a European project. This paper presents an overview of the database and its available tools, and the main results from a case study on Hellenic buildings that reveals relevant characteristics. The Hellenic database included a sample of 250 buildings from different regions in Greece, with a breakdown that is representative of the national building stock. The main results focus on the buildings’ energy performance, thermal envelope characteristics and the exploitation of solar thermal energy. [Copyright &y& Elsevier]

Abstract: Energy recovery systems can be used in HVAC to reduce energy consumption by recovering wasted energy from the exhausted air to pre-cool inlet fresh air. In this paper, experimental study of utilizing cooling coil (CC) and cooling coil combined with heat exchanger (CCHE) has been developed. Considering the different climate zones in Iran, the experimental study has been done for the areas with high humidity content. In each case, the effects of air-to-air heat exchanger (HE) on the sensible and latent cooling load are investigated. The analysis gives the applicability of HE in Iran for various operational conditions to obtain air with lower moisture content. In CCHE systems more latent load quota is allocated in cooling coils and lower air humidity ratio can be obtained. Also in the cities with higher dew point depression (difference between dry-bulb and dew point temperature) more humidity reduction is achieved and the difference between latent load quotas of CCHE system is higher than CC system. [Copyright &y& Elsevier]