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Abstract In this paper, a new method entitled "BBEE (Building Blocks Energy Estimation)" for estimating energy performance at the district level is proposed. It consists of two branches, namely the BBEE algorithm and an energy database of a typical zone. This method is used to keep architects and urban planners informed of the energy performance of their design by clustering zones and looking up corresponding energy intensities from the database. Because the related energy databases are preexisting, energy performance modeling and simulation are not required from the user. On the other hand, the database is set up and continuously replenished by parameterization simulations with a basic model of typical zones. This task was separated from the estimation process and operated by experts, which shortened the process and reduced modeling errors. As a case study, an urban district with eight buildings was estimated under three climate conditions separately following the proposed BBEE method. Results were compared with the full-model simulation using a simulation tool called DeST. The difference in annual heating demand between estimation and simulation was reported as less than 6% in all three cases. The potential applications and limitations of the proposed BBEE method are discussed at the end of this paper. Although further improvements are still required, the new estimation method could be helpful for energy performance estimation at the district level at the early stage of design. [ABSTRACT FROM AUTHOR]

Occupant behaviour on air conditioning directly influences building energy consumption. Current building energy simulation typically assumes that occupants operate air conditioners ideally ignoring the stochastic characteristic of occupant behaviour, which leads to a large deviation of predicted energy performance from real consumption. This paper proposed a methodology framework for modelling occupants’ stochastic behaviour on air conditioning. This method combined measured data, statistical analysis and logistic regression to derive stochastic behaviour models that give the probability of when and above which temperature occupants may turn on air conditioning, at what temperature they may set and when they may turn off air conditioning. The behaviour models developed in this paper were further incorporated in widely used building simulation engine—EnergyPlus. The accuracy of the developed simulation model was validated against field measurement. Using this model, the cooling energy performance was simulated and compared with results from building energy standard based settings. The result shows that simulation using settings according to building energy standard over-predicts cooling load and total cooling energy requirements by 113% and 5.6 times respectively, which are very large discrepancies and may lead to a misunderstanding of energy savings potential of energy efficiency measures. The methodology developed in this paper has generality and can be extended and applied in other buildings for constructing behaviour models of air conditioning. The limitations of the current research as well as future research works were also discussed. [ABSTRACT FROM AUTHOR]

Research has shown the large effect that occupants have on buildings' performance. Uncertainties related to the actual energy consumption of buildings increase the risks for the investments in low carbon technologies. Monitoring building occupancy can potentially decrease these uncertainties by providing more information about the occupants and their behaviour. The objective of the investigation is to establish an approach to inform the design process (e.g. building simulation) by addressing the complexity of occupants behaviour. The approach integrates information on occupants' behaviour and attitudes regarding energy use and indoor conditions to determine the requirements for building simulation and energy calculations. This paper presents the results of two monitoring campaigns in which the approach was employed. The monitoring campaigns focused on two owner-inhabited apartments in Spain and three social rental dwellings in The Netherlands. The results have given first insights of the power of the methodology to obtain detailed and understandable data on the occupancy patterns. This investigation highlighted the importance socio-economical status and attitudes towards energy conservation on occupants' behaviour in residential buildings. The methods described in this paper can be readily used to develop occupancy and heating profiles for monitored households to be used in building simulation programs. [ABSTRACT FROM AUTHOR]

Recent technical guidance has suggested that comfort and energy efficiency should not be seen as mutually exclusive [CIBSE, “TM54: Evaluating operational energy performance of buildings at the design stage”, 2013]. Currently, however, there is a lack of comprehensive understanding of energy use during building operation and how it influences user comfort. Through comparison of the complex relationships between energy, thermal comfort, and environmental strategy in two flexible higher-education buildings in Sheffield, this paper demonstrates how designers can utilise aspects of active and passive design to deliver more comfortable, lower-energy workspaces. Analysis of the authors’ post-occupancy evaluation of each case study examines what lessons might be learnt and applied to other institutional buildings in order to save energy without compromising occupant comfort. The findings illustrate how perceptions of comfort can be improved by increasing the degree of environmental control occupants have without necessarily increasing energy consumption. The paper highlights the significance of occupancy patterns to a complete understanding of energy efficiency and comfort, and speculates that the prediction and assessment of energy per occupant may have an important future role to play in bridging the gap between energy performance and comfort. [ABSTRACT FROM AUTHOR]

Abstract Dwellings with no heating, ventilation and air conditioning (HVAC) systems are commonly found in many countries. The long-term thermal performance of these buildings can be assessed based on hourly data of occupant thermal discomfort integrated over the required timespan (e.g. total degree hours of discomfort per year). This approach can be easily applied when simulation is adopted in the assessment, but field studies using this approach are rare as they would require complex, costly and long measurement/survey campaigns. This paper addresses the challenges on conducting field studies on long-term thermal performance of dwellings with no HVAC system by introducing a novel performance indicator: the Seasonal Thermal Sensation Vote (S-TSV). S-TSV adopts the standard 7-point thermal sensation scale and is based on the perceived overall thermal sensation recalled by the user of the building for specific seasons and times of day. The new performance indicator is not intended to replace existing ones, but to complement them in the understanding of the complex thermal performance processes taking place in buildings with no HVAC. S-TSV was applied in a field study targeting a small sample of dwellings in Brazil. Results demonstrate the capabilities of S-TSV to describe trends in buildings performance in this sample. S-TSV also assisted on the identification of relationships between such performance and some independent variables addressed in this field study (e.g. windows operation, footwear and income), considering a threshold of p -values <0.05 on the chi-square statistic test. [ABSTRACT FROM AUTHOR]

Occupants account for a significant impact on building performance through their interactions with zone level building components. Empirically-derived occupant models, despite their potential to represent occupants’ impact in building performance simulation (BPS), have minimal penetration in design and code compliance processes. Instead, occupants are represented with static schedules or simple deterministic triggers. The objective of this paper is to better understand the influence of assumptions made in representing occupant interactions with building components over a BPS model's energy use and comfort predictions, as well as their ability to promote better design decisions. To this end, the energy and daylight performance of a generic perimeter office space in Ottawa, Canada were evaluated using a set of comprehensive performance metrics. Results indicate that representing dynamic occupant–building interactions lead to different energy predictions from the static schedules. The maximum difference in the total electricity use was for window-to-wall area ratios (WWR) of 20%, which was about 30% higher with the stochastic cases than the blind-open static cases. WWR 60% and 40% generally yielded the lowest lighting electricity use with the static and stochastic cases, respectively. This paper emphasizes the importance of incorporating empirically-derived dynamic occupant models for simulation-aided design and code compliance. [ABSTRACT FROM AUTHOR]

In a hybrid cooling system, an indirect evaporative cooling (IEC) unit is installed before an air handling unit to pre-cool the incoming fresh air, in order to reduce the energy consumption of the air-conditioning system. When the system is applied in humid regions, as the dew point temperature of the fresh air is higher, condensation will probably occur in the dry channels of IEC unit. However, the model of IEC unit considering condensation had been seldom studied, which would become an obstacle in predicting the performance of the hybrid system. In order to evaluate its energy saving potential precisely, the paper aims to establish a short-cut model for predicting the annual performance of the hybrid cooling system considering condensation in IEC unit. This paper firstly presents the analytical models for IEC under non-condensation, totally condensation and partially condensation states and proposed a method for judging the three states as well. The models were validated by the published data from literatures. The validated model was then incorporated with TRNSYS for predicting the performance of an IEC hybrid cooling system in a wet market in Hong Kong and the annual simulation results were validated by a field measurement with good agreement. [ABSTRACT FROM AUTHOR]

The requirements concerning energy performance of buildings and their internal installations, particularly HVAC systems, have been growing continuously in Poland and all over the world. The existing, traditional calculation methods following from the static heat exchange model are frequently not sufficient for a reasonable heating design of a building. Both in Poland and elsewhere in the world, methods and software are employed which allow a detailed simulation of the heating and moisture conditions in a building, and also an analysis of the performance of HVAC systems within a building. However, these systems are usually difficult in use and complex. In addition, the development of a simulation model that is sufficiently adequate to the real building requires considerable time involvement of a designer, is time-consuming and laborious (Menberg et al., 2019) [1]. A simplification of the simulation model of a building renders it possible to reduce the costs of computer simulations. The paper analyses in detail the effect of introducing a number of different variants of the simulation model developed in DesignBuilder on the quality of final results obtained. The objective of this analysis is to find simplifications which allow obtaining simulation results which have an acceptable level of deviations from the detailed model, thus facilitating a quick energy performance analysis of a given building. [ABSTRACT FROM AUTHOR]

Polycarbonate panels could be considered as a suitable and cheap solution for walls, roofs, and sheds in non-residential buildings and, at the same time, granular silica aerogel is one of the most promising nano-materials for energy saving in buildings. In the paper, three types of advanced multiwall PC panels (thickness 16, 25, and 40 mm) with translucent granular aerogel were investigated by experimental (thermal and optical) and numerical characterization. By comparing thermal performance of air and aerogel-filled PC systems, it can be noticed that the impact of the aerogel is remarkable: the reduction in U-value is 46%-68%, depending on the aerogel layer thickness. U-value is 1.4 W/m 2 K for the 16 mm thickness sample and it is 0.6 W/m 2 K when the thickness increases up to 40 mm. The systems keep their performance in horizontal position, when they are used as roofs. Light transmittance is 0.61 and 0.42 for 16 mm and 40 mm respectively and the reduction with respect to air-filled panels is acceptable (15%) for 16 mm and significant (40%) for 40 mm thickness. The aerogel has also a remarkable impact on the reflectance spectrum , especially between 400 and 1400 nm. The solar factor is 0.58 for 25 mm thickness, quite similar to the low-e glazing one. Finally, energy simulations for a case study showed that aerogel-filled PC systems outperform conventional double glazing systems both for heating and cooling energy demands. However, when compared to low-e glazings, the benefits of the translucent material (also considering the highest thickness) in the interspace are lower for heating and negligible for cooling energy demands. The aerogel-filled polycarbonate systems could be a valid solution for non-residential buildings, enhancing the thermal performance and the light control of the building envelope, especially when they are used as roofs. [ABSTRACT FROM AUTHOR]

This paper analyses annual energy performance of atrium type hotel building in Belgrade. The objective is to examine the impact of the atrium on the hotel building’s energy demands for space heating and cooling. Integrated approach through numerical simulations that include Belgrade climate data and thermal comfort parameters, indicates an optimal model of hotel building with atrium for this area. Building energy simulation is carried out using EnergyPlus simulation engine, as a basic tool in the process of building energy optimization. The methodological approach includes the creation of a hypothetical model of an atrium type hotel building, numerical simulation of energy performances of several design alternatives of the hotel building with atrium, and comparative analysis of the obtained results. The main task of analysis is to change certain parameters in the particular model (for example, building structure, orientation, etc.) and to observe how the changes influence energy performance of the building. The goal of this research is to show that the atrium contributes to the heating and cooling energy savings in the rest of the building, but also that the atrium itself demands a lot of energy for its air-conditioning. The most sustainable solution should be to cover energy demands for atrium by using the renewable energy sources. In this case, the atrium can contribute to the energy efficiency of the hotel building in Belgrade climatic conditions, thus reducing its negative impact on the environment. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of occupant lifestyle patterns on the energy performance of the residential buildings with various building envelopes in different climate zones. For this purpose, an existing multi-family apartment building in Iran was selected as the experimental residential building and the validity of energy simulation was examined based on the real data of the building energy consumption. The energy demand of the building before and after renovation was simulated via EnergyPlus for different climate zones. The sensitivity analyses confirmed that the occupants’ behavior has a significant impact on the building's thermal energy usage especially in hot climate areas and can change the heating and cooling loads up to about 90%. Using the validated model, a parametric study was performed to investigate the influences of the occupant's behavior on the efficiency of the building envelope including window and cladding materials in different climate zones. The results show that the interaction between the occupants’ behaviors and envelope materials is significant in that the occupant behaviors can change the strategy of choosing the envelop material types. Fluctuation of thermal energy consumption caused by changing of window types can rise to 20% for this case study. Also, it is shown that underestimating the level of occupancy loads can exaggerate the effects of the envelope on the thermal energy consumption rate. Overall, this study emphasizes the importance of applying near actual user behavior data on energy simulation analyses performed for the studies of building sustainability and lifecycle assessment. [ABSTRACT FROM AUTHOR]

There are numerous strategies available to design and construct a low energy or nearly zero energy building (NZEB). However, the design strategy for a building depends on a high number of factors including location, climate, cost, available resources, etc. For instance, for countries like Ireland, which have a temperate oceanic climate, a key to achieving NZEB is a high thermal and air tightness performance of the building envelope, installing highly efficient space and water heating systems, and utilising renewable technologies for energy and heat generation. The challenge is to find the best combination of design strategies that would tackle the energy performance problems of a particular building. For example, is it better to design a super-insulated building with minimum heating requirements, or provide less insulation but install a large amount of renewable energy sources? This paper presents the outcomes of a number of case study buildings in Ireland, which focus on the life cycle cost and environmental analysis (using energy and global warming potential as indicators) of NZEBs using various heat sources, such as a gas boiler, biomass boiler, a domestic gas fired combined heat and power unit, heat pump and renewable technology. With the de-carbonisation and increased efficiency of the electricity grid, the low global warming potential (GWP) emissions of biomass fuels and the depletion of fossil fuels, future buildings should be (i) designed and constructed to be super-insulated with high air-tightness performance resulting in minimum heating requirements and (ii) operate with heating systems that have low impact on the natural environment, such as a biomass boiler or heat pump. [ABSTRACT FROM AUTHOR]

In recent years, the construction industry has been comprehensively focusing on energy performance of buildings and on achieving higher standards of living comfort. One of the most sophisticated ways to attain both at the same time is (re)achieving building’s climate balance by using bioclimatic design. Therefore, the main goal of this paper was to present a bioclimatic potential prognosis and to show its application on an example of the Alpine-Adriatic region. The bioclimatic potential prognosis was made for 21 characteristic locations. For this purpose, bioclimatic chart plots were made using elementary weather data and additionally, the actually received solar irradiance was precisely considered at every location. The latter was shown to have a large influence on the analysis results. Furthermore, an evaluation of performed bioclimatic potential prognosis was made with simulations of a generic building model using Energy Plus. The generic building model was tested in five selected locations and the heating and cooling demand results were compared with the bioclimatic potential analysis. The results showed that the application of the presented method can indicate which passive solutions should be applied in building design at a specific location in order to facilitate smaller energy usage and consequential higher indoor comfort. In addition, the presented approach can be used in order to incorporate the latest or predicted climate data into bioclimatic potential analysis. The latter has a significant influence on the design of buildings of the future. [ABSTRACT FROM AUTHOR]

Abstract: The increase of peak and energy demand during the cooling season is becoming a crucial issue, as well as the intensification of the urban heat island effect. This trend is observed at several latitudes, including areas where overheating was unknown at building and urban levels. This phenomenon involves different issues: reduction of greenhouse gases, quality and comfort in outdoor and indoor environment, security of energy supply, public health. The building sector is directly involved in this change and adequate solutions can provide great benefit at energy and environmental levels. Roofs in particular are envelope components for which advanced solutions can provide significant energy savings in cooled buildings or improve indoor thermal conditions in not cooled buildings. Cool materials keep the roof cool under the sun by reflecting the incident solar radiation away from the building and radiating the heat away at night. Roofs covered with vegetation take benefits of the additional thermal insulation provided by the soil and of the evapo-transpiration to keep the roof cool under the sun. These two technologies are different in: structural requirements, initial and lifetime maintenance costs, impact on the overall energy performance of buildings. This paper presents a numerical comparative analysis between these solutions, taking into account the several parameters that affect the final energy performances. By means of dynamic simulations, the paper depicts how cool and green roofs can improve the energy performance of residential buildings in different localities at Mediterranean latitudes. [Copyright &y& Elsevier]

The reduction of energy consumption and CO 2 emissions in buildings has become an essential field of study in the recent years. Simplified design tools, used in the first design stages, can be of great help in adopting concrete decisions that will, at the end, allow these to be reduced. This paper presents a new predictive model for office buildings in Chile. Starting from the 1,386,000 study cases pursuant the ISO 13790:2008 standard, 18 multivariable regression models have been generated, 9 for energy consumption and 9 for CO 2 emissions., They have been adapted to each climatic zone in Chile. In these case studies, 8 fundamental variables have been considered to cover the design parameters. This research considers number of stories (NS), floor area (FA), form ratio (FR), window-to-wall ratio (WWR), coefficient of performance (COP), Energy efficiency ratio (EER), heating emission factors (HEF) and cooling emission factors (CEF). The models generate an R 2 between 91.81% and 98.05% for energy consumption and between 96.83% and 99.56% for CO 2 emissions, with the results of this research being incorporated into future regulations and into the first stages of design for office buildings in Chile. As an expected outcome, the model will contribute to reduce, or at least contain, energy consumption and CO 2 emissions associated with office buildings in the future. [ABSTRACT FROM AUTHOR]

The existing housing stock plays a major role in meeting the energy efficiency targets set in EU member states such as the Netherlands. The non-profit housing sector in this country dominates the housing market as it represents 31% of the total housing stock. The focus of this paper is to examine the energy efficiency measures that are currently applied in this sector and their effects on the energy performance. The information necessary for the research is drawn from a monitoring system that contains data about the physical state and the energy performance of more than 1.5 million dwellings in the sector. The method followed is based on the statistical modeling and data analysis of physical properties regarding energy efficiency, general dwellings’ characteristics and energy performance of 757,614 households. The outcomes of this research provide insight in the energy efficiency measures applied to the existing residential stock. Most of the changes regard the heating and domestic hot water (DHW) systems, and the glazing. The rest of the building envelope elements are not improved at the same frequency. The results show that the goals for this sector will be hard to achieve if the same strategy for renovation is followed. [ABSTRACT FROM AUTHOR]

Semi-transparent photovoltaic (STPV) windows, which can not only admit daylight into space but also generate electricity, have been widely used as a part of building components in recent years. This paper compares the overall energy performance between STPV windows and commonly used energy-efficient windows, viz. double-pane and Low-E windows, in Hong Kong. A new type of see-through amorphous silicon (a-Si) photovoltaic (PV) module was adopted, and this PV module has higher efficiency compared with other commercialized a-Si PV modules with the same visible transmittance. First, a series of testing were carried out to get the technical parameters of this PV module. Second, the simulation models were developed theoretically, and power, thermal and daylighting performance of different windows were analyzed by EnergyPlus accordingly together with the input weather data of typical meteorological year (TMY) in Hong Kong. Then, based on the simulated energy uses of the air-conditioning and the artificial lighting of the room, as well as the power generation of the STPV windows themselves, the overall energy performance was evaluated. The results indicate that STPV glazing can save up to 18% and 16% total electricity per year respectively in comparison with the clear single and double-pane glazings in cooling dominated areas like Hong Kong. The overall energy performance of Low-E glazing and STPV glazing is very close to each other, which means that STPV glazing is quite energy-efficient. In Hong Kong, southwest is the best orientation for power generation for STPV windows and south is the optimum orientation for STPV window installation in terms of achieving the best overall energy performance. [ABSTRACT FROM AUTHOR]

Evaluation methods can be used to determine what constitutes good energy performance in a building. With an increasing focus on energy use of buildings worldwide, this evaluation assumes a fundamental importance. This paper provides a comprehensive review of the available methods for analysing, classifying, benchmarking, rating and evaluating energy performance in non-domestic buildings. Methodologies are grouped in five categories: engineering calculations, simulation, statistical methods, machine learning and other methods. Techniques for evaluating buildings are described, their principal applications are shown and limitations are identified. The use of performance evaluation in energy efficiency programmes and standards is mapped. There is a need to further develop interactions between the main modelling techniques to produce simple, robust and validated models. Also, evaluation techniques must be developed to consider comfort or service provision in the buildings as a factor in energy performance. [ABSTRACT FROM AUTHOR]

Industrial halls pose high energy saving potential that is not yet explored under current design practice. Common design approaches such as parametric study or optimization are largely constrained by the assumptions and do not promote flexibility in the decision making process. Based on the unique characteristics of industrial halls, this paper develops a full factorial design space exploration approach to support multi-criteria design decision making. Energy performance, environmental impact, and cost effectiveness are studied over the whole life cycle. The approach is demonstrated with a case study of a warehouse in Amsterdam. Design parameters of interest are the insulation values, construction types, skylight coverage and transpired solar collector coverage. The results indicate that this approach offers design solutions that might not be otherwise identified. The non-case-specific one-time investigation allows objective space of derived performance to be generated dynamically based on even changing information or inputs specified by the users at the time of making the decision. This new design support approach facilitates designers to assess feasibility of any design solution based on their own desired set of performance requirement under different probable scenarios in the future. [ABSTRACT FROM AUTHOR]

Directives in the European Union are ensuring that buildings in this region are moving towards nearly zero energy buildings (NZEB). For countries like Ireland, which has a temperate oceanic climate, a key to achieving NZEB is to have high thermal and air tightness performances of the building envelope. Consequently, as the operational energy of the building reduces, the embodied energy (and embodied global warming potential) typically increases as a proportion of the lifecycle energy of the building due to increased embodied energy of the building envelope and the lower operational energy. In order to assess if a design strategy is in fact sustainable, it is becoming essential to evaluate environmental and economic LCA of building design strategies. This paper presents the outcomes of a number of case study buildings in Ireland, which focuses on the full environmental and economic lifecycle assessment of buildings to assess the impact changes in building regulations are having on the contribution of both the construction and operation of a building's lifecycle as they move towards NZEB standards. If designed with a focus on achieving a high thermal and air tightness, a building with an embodied energy intensity less than a building that achieves compliance with 2011 Irish building energy performance regulations can achieve a NZEB standard. [ABSTRACT FROM AUTHOR]

In the last decade textile architecture has become increasingly popular: fabrics and foils are more and more used as skins for permanent and enclosed buildings. The thermal-physical behavior of air-supported membrane structures, characterized by low thermal inertia and poor insulation, is definitely different from the traditional architectures, although required comfort levels are often similar. While the thermal behavior of the wider spread ETFE foil cushion system is still investigated, a quantitative assessment of the double-layered fabric skin energy performance is still lacking. This paper studies the latter membrane system, focusing on the evolution of air-supported envelopes for sports halls, from single layer to double layer membranes, either based on pneumatic cushions or on continuous air gaps. By performing measurements on running sports halls and dynamic simulations, the winter energy performance, the comfort conditions and the internal surfaces condensation risk of a typical sport hall in Northern Italy are evaluated. An insight is given into the envelopes dynamic behavior and energy balance. Double layers envelopes allow saving from 11% to 18% of the heating energy compared to single layer. Moreover, further energy saving strategies are proposed and quantified, considering low-emissivity coatings, reduction of the cracks areas, modifying indoor air set points. [ABSTRACT FROM AUTHOR]

The paper focuses on the assessment of the windows’ contribution to the energy performance of buildings in the warmer regions of Europe. This is derived by calculating the cooling energy index q c and the area weighted energy needs for different window configurations installed on a reference room for two different building uses, office and residential. The examined window types differed with regard to their thermophysical and optical properties ( U - and g -value), geometry (frame and window fractions) and orientations. The energy parameters used for the performance assessment were calculated with the help of a dynamic simulation tool for a location with a representative Mediterranean climate. The extensive multi-parametric analysis exhibited interesting results. It was found that for the cooling mode the energy performance of windows in warm climates is influenced significantly by their thermophysical properties. More specifically, the impact of solar transmittance is significant and its optimal selection can contribute in minimizing the energy consumption, especially in environments with controlled ventilation, such as offices. On the contrary, advanced fenestration products with low thermal transmittance seem to behave unfavorably, since their extremely low thermal transmittance prohibits the dissipation of heat toward the ambient environment and results ultimately in higher cooling energy loads. [ABSTRACT FROM AUTHOR]

Building energy assessment methods, used in a regulatory context, impose a calculation procedure under restricted and predefined conditions to check preset energy performance levels. Standardized boundary conditions and input data are implemented allowing for objective evaluation of various building designs. Focusing on school buildings in particular, these specific boundary conditions are however often inaccurate or even unavailable. Therefore, throughout this paper, typical school characteristics and their uncertainty are studied. The impact on the energy demand calculations is then demonstrated in an uncertainty analysis using the Monte Carlo analysis method combined with the Latin Hypercube sampling technique. A sensitivity analysis, using the elementary effect method of Morris, reveals the set point temperature, load and users’ profiles of lighting and equipment in class rooms as the most dominant input parameters on which additional surveys and questioning are focused to determine possible inaccuracies and to define, where necessary, new, more realistic boundary conditions. As a final result, a list of representative boundary conditions for Flemish schools is determined which can be used directly or can be converted into averaged input data for simplified calculation methods. [ABSTRACT FROM AUTHOR]

This paper provides a comparative study of the energy efficiency of a conventional ventilating and air conditioning (VAC) system with three configurations. This system was used to cool an experimental room in an office building in more control scenarios realised by adopting different cooled water temperatures and chiller cooling systems. In this purpose, an air–water mist cooled system for an air-cooled chiller is proposed. Depending on the components, the analysed VAC system has the following configurations: (1) air handling unit (AHU) and fan-coil units (FCUs); (2) air handling unit (AHU); and (3) heat recovery unit (HRU) and fan-coil units (FCUs). The electricity consumption weight of the equipment of each VAC system, the total energy consumption and the influence of control parameters on this consumption are analysed. The results of the experiments indicate that the optimal efficiency VAC system in office buildings includes an AHU and FCUs with an air–water mist cooled chiller and a cooled water temperature of 8 °C. For this system, a mathematical model is developed to minimise the electricity consumption by optimal control, where the consumption depends only on non-controlled parameters (solar radiation intensity and outdoor air temperature). This model is verified with actual measurements to confirm its accuracy, and a good agreement between the prediction and measurement is achieved. Additionally, the assessment of thermal comfort in the experimental office is performed based on the PMV-PPD model using the ASHRAE Thermal Comfort programme. The obtained results demonstrate that the AHU&FCUs system assures an increase in thermal comfort. Finally, a TRNSYS simulation model of energy consumption and PMV-PPD indices for the AHU&FCUs system is developed and experimentally validated. [ABSTRACT FROM AUTHOR]

In this paper, dynamic simulation was used to compare the energy performance of three innovative HVAC systems: (A) mechanical ventilation with heat recovery (MVHR) and micro heat pump, (B) exhaust ventilation with exhaust air-to-water heat pump and ventilation radiators, and (C) exhaust ventilation with air-to-water heat pump and ventilation radiators, to a reference system: (D) exhaust ventilation with air-to-water heat pump and panel radiators. System A was modelled in MATLAB Simulink and systems B and C in TRNSYS 17. The reference system was modelled in both tools, for comparison between the two. All systems were tested with a model of a renovated single family house for varying U-values, climates, infiltration and ventilation rates. It was found that A was the best system for lower heating demand, while for higher heating demand system B would be preferable. System C was better than the reference system, but not as good as A or B. The difference in energy consumption of the reference system was less than 2 kWh/(m 2 a) between Simulink and TRNSYS. This could be explained by the different ways of handling solar gains, but also by the fact that the TRNSYS systems supplied slightly more than the ideal heating demand. [ABSTRACT FROM AUTHOR]

Highlights: [•] This paper analyses the energy performance of LEED certified buildings. [•] We have conducted energy simulations with actual data validations. [•] The results show that green vegetation on LEED certified buildings is not economically viable. [Copyright &y& Elsevier]

Abstract: An archetypal simulation model of office building representing variability in UK office building stock by parameterising built form, construction elements, occupancy/usage and operational/control strategy has been developed thus enabling detailed energy performance simulation to be used for stock modelling and parametric studies. The paper discusses the building characteristics needed to be considered for energy performance simulation, their values, and how they can be used in parametric studies. These parameters include built forms, fabrics (including thermal mass and insulation positioning), glazing percentages and characteristics, daylight and solar control measures and activity and operational related parameters (heating and cooling set points, ventilation rate, occupancy density and metabolic rate, equipment and lighting gain). The default parameter values suggested for the archetypal simulation model reflect typical existing and currently proposed UK office building stock. An archetypal model, combined with parametric studies, can be used in assessing energy performance of building stock and evaluating adaptation/retrofitting strategies. [Copyright &y& Elsevier]

Abstract: This paper described the development of regression models which are able to predict office building annual heating, cooling and auxiliary energy requirements for different HVAC systems as a function of office building heating and cooling demands. In order to represent the office building stock, a large number of building parameters were explored such as built forms, fabrics, glazing levels and orientation. Selected parameters were combined into a large set of office building models (3840 in total). As different HVAC systems have different energy requirements when responding to same building demands, each of the 3840 models were further coupled with five HVAC systems: VAV, CAV, fan-coil system with dedicated air (FC), and two chilled ceiling systems with dedicated air, radiator heating and either embedded pipes (EMB) or exposed aluminium panels (ALU). In total 23,040 possible scenarios were created and simulated using EnergyPlus software. The annual heating and cooling demands and their HVAC system''s heating, cooling and auxiliary energy requirements were normalised per floor area and fitted to two groups of statistical models. Outputs from the regression analysis were evaluated by inspecting models best fit parameter values and goodness of fit. Based on the described analysis, the specific regression models were recommended. [Copyright &y& Elsevier]

[Display omitted] For almost two decades, the Zero Energy Buildings (ZEB) standard has epitomized a commitment to the high energy performance of buildings. Nevertheless, the applicability of ZEB in hot climates is currently limited and furthermore, in light of the current limitations of traditional building energy modeling methods, new methods are necessary to effectively evaluate the energy balance potential of larger districts. To help bridge this gap, this paper introduces solar-based (both sun-hours and solar irradiation) and geometry-based prediction metrics to be used in optimization studies to evaluate the impact of urban morphology on the energy balance of residential blocks in hot urban contexts. These prediction metrics are derived from the simulated energy performance of 1,944 parametric variations of residential blocks in Tel Aviv. In a regression analysis, these metrics recorded high correlation with energy demand, energy supply and the balance between them. To test the applicability of these metrics for optimization, the RBFMOpt method is employed in a multi-objective optimization study of the energy supply and demand of a nine-block residential district in Tel Aviv. Detailed energy simulations are performed for the best non-dominated results from the solar and geometric optimization studies and compared to the non-dominated results from a full energy optimization run. The results indicate that these metrics - the solar and geometric area-weighted exposure and shading indices - can serve as effective energy performance indicators to inform early-stage morphological decisions making. This workflow promotes urban energy optimization towards more harmonized energy supply and demand driven approaches. [ABSTRACT FROM AUTHOR]

• We selected three benchmarking methods to establish building energy benchmarking models based on a sample of 45 hotel buildings in China. • We compared the three benchmarking methods in terms of consistency, robustness and explanatory ability. • The energy efficiency performance obtained from the three methods were found to be inconsistent. • We came up with suggestions based on comparative analysis for policy-makers to develop building energy benchmarking programs. A reasonable building energy efficiency benchmarking program plays an important role in energy consumption control and supervision. Previous studies have focused on the process of establishing a single benchmarking method, but few have compared the performances and outcomes of different methods. To fill this gap, this paper selects three benchmarking methods—multiple linear regression (MLR) based on Energy Star, stochastic frontier analysis (SFA) and the descriptive statistics method (DSM) based on the national energy consumption standard in China—to develop benchmarking models. We demonstrate each method using data on the energy and building characteristics of 45 four- and five-star hotel buildings located in Chongqing, China. To compare the consistency, robustness and explanatory ability of the three methods, we first utilize the Spearman rank correlation analysis to test whether these methods have consistent energy efficiency ranks and then present Sankey diagrams to further reveal the interactions of the estimated energy efficiency grades obtained from the three methods. It is found that the results of DSM and SFA are most consistent, while MLR vs. SFA and MLR vs. DSM present significant differences in evaluating building energy performance. In addition, DSM is more robust for evaluating the ranks of sampled buildings, while SFA is more robust for evaluating energy efficiency grades. Furthermore, we discuss the explanatory ability of each method. In addition to the building characteristics, the design and operational characteristics of the HVAC system have great effects on building energy consumption. Finally, we present suggestions for policy-makers regarding the development and implementation of the building energy benchmarking program in Chongqing and for the management of buildings with different energy performances to further improve the energy efficiency. [ABSTRACT FROM AUTHOR]