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This paper investigates factors associated with variation in daily total (electricity and gas) energy consumption in domestic buildings using linked pre-COVID-19 smart meter, weather, building thermal characteristics, and socio-technical survey data covering appliance ownership, demographics, behaviours, and attitudes for two nested sub-samples of 1418 and 682 British households selected from the Smart Energy Research Laboratory (SERL) Observatory panel. Linear mixed effects modelling resulted in adjusted R2 between 63% and 80% depending on sample size and combinations of contextual data used. Increased daily energy consumption was significantly associated (p -value < 0.05, VIF < 5) with: households living in buildings with more rooms and bedrooms, that are older, more detached, have air-conditioning, and experience colder (more heating degree days) or less sunny weather; households with more adult occupants, more children, older adult occupants, higher heating temperature setpoints, and that do not try to save energy. The results demonstrate the value of smart meter data linked with contextual data for improving understanding of energy demand in British housing. Accredited UK researchers are invited to apply to access the data, which has recently been updated to include over 13,000 households from across Great Britain. This paper provides guidance on appropriate methods to use when analysing the data. [ABSTRACT FROM AUTHOR]

Abstract: Photovoltaic (PV) connected systems are experiencing rapid market growth. This is due to the continually downward trend in PV cost together with government support programs. A scenario has been assumed to analyse the geographical market of PVs. The results provide clear evidence of the influence that some variables have on the profitability of PV investments. This study presents a model for minimising investment risk and maximising the return of a renewable energy portfolio in Italy. The value of the paper is in showing that the energy and CO2 reduction potential that can be reached through consumer-oriented policy measures, but the paper also looks at the effectiveness and social implications of such measures. Private households possess immense unused potential for energy reductions (and climate protection) that could be realised through gains in energy efficiency, behavioural changes, and extended use of low-emission energy. The focus of energy policy has been on businesses rather than on private households, which are only partly captured by direct policy measures. To achieve the goals of climate policies, the current political and scientific discussion increasingly considers measures that aim to reduce energy consumption in the private sector. Quantitative estimates are presented for economic indicators and will show the various effects of policy measures on the implemented household types. [Copyright &y& Elsevier]

Abstract: The success of modeling the sustainable performance of the residential building envelope will be to a great extent associated to the sustainable energy performance indicators used. The sustainable energy performance indicators that these building assessment models are developed around should be chosen by taking into account the targeted objectives. However, it is very common to find building performance assessment models that do not take into account these considerations and therefore have a limited capability and scope. This leads to inadequate aggregate indicators for the actual assessment of the sustainable performance of the building envelope for a sustainable energy efficient building. The focus of this paper is to investigate the principal sustainable energy performance indicators for modeling the sustainable performance of the residential building envelope and develop an approach for determining the most appropriate sustainable energy performance indicators. In doing that, this paper provides an overview of previous research on sustainable energy performance indicators and discusses conceptual framework for developing sustainable energy performance indicators. In order to identify these indicators that influence the capability of building performance assessment models, a comprehensive survey of construction industry professionals was conducted using questionnaire survey technique while the data was analyzed using correlation analysis techniques. [Copyright &y& Elsevier]

The modeling and simulation of domestic hot water systems, including solar thermal and co-generation technologies, relies on accurate, high time-step resolution water consumption profiles. Due to the expensive nature of field studies, previous profiles have been limited in number of participants, or have been generated synthetically using probabilistic modelling techniques. The Solar City program in Halifax has measured hot water flow rate and temperature data in 119 homes at a time-step of 1 min; and includes a survey of occupancy rates and other relevant meta-data. In this paper, we discuss the data acquisition and processing (with a focus on flow rate data), and conduct analysis to reveal consumption trends and produce a new set of time-step profiles for modeling and simulation. Average hot water consumption per household is 172 L/day with a strong dependency on number of occupants. The hourly profile peaks twice daily, and shifts by several hours on Sunday. The average draw temperature was found to be 51.8 °C, which is lower than the default value of 55 °C applied by many building modeling/simulation packages. The average cold water supply temperature was found to be roughly sinusoidal about 12.4 °C with approximately one-month lag compared to ambient air temperature. [ABSTRACT FROM AUTHOR]

This paper proposes a new method for an optimal control of the heating system at the building scale. This control is a new approach of energy planning that aims to decrease the heating consumption/expenses over a defined prediction horizon while respecting the occupants’ thermal comfort. It employs a simplified building thermal model to simulate the building thermal behavior taking into consideration the weather predictions. This approach is based on the application of Monte Carlo method, i.e., a random generator for the heating system scenarios. The aim is to determine the optimal heating plan for the prediction horizon that fulfills the constraints regarding the thermal comfort of occupants and the minimization of the energy consumption/expenses together with achieving a load shedding. [ABSTRACT FROM AUTHOR]

The use of software tools to aid building design, or to show compliance, is now commonplace. This has motivated investigations into the potential of optimisation algorithms, used in such software, to automatically optimise designs, or to generate a variety of near-optimal designs. Optimisation always requires the evaluation of a large number of possibilities, before a final selection is made. Normally when using a building simulator to assess the quality of designs, all possible solutions in the early stages of optimisation (when there is a high volume of choices) are evaluated using the same tool, so that the computational time for the assessment of each of the possibilities is the same as the time required for the final, refined choice of solutions. This paper suggests using a method of evaluation which changes as the algorithm evolves: whereas accuracy is initially compromised to improve the speed of the algorithm, the process is subsequently altered to produce a more accurate, evaluation process. This is a case of dynamic optimisation that requires an algorithm able to cope with changes in the objective landscape. A self-adaptive evolutionary strategy has been chosen, for its ability to “learn” about changes, and the influence of the different decision variables in the objective function as they arise. The results show that this method can reach the same optimal design, with substantially lower computational time than the optimisation methods found in the literature. [ABSTRACT FROM AUTHOR]

Abstract: Jordan heavily relies on imported oil and gas for meeting its energy need as the same time the construction sector consumed more than half of the total electricity consumption in Jordan in 2008. In order to provide the occupants with thermal comfort at least cost, applying energy saving measures into early design stage can be significant to achieve this goal. This paper discusses an assessment of best orientation of the building, windows size, thermal insulation thickness from energetic, economic and environmental point of view for typical residential building located in Mediterranean region. The results show that about 27.59% of annual energy consumption can be saved by choosing best orientation, optimum size of windows and shading device, and optimum insulation thickness. The Life Cycle Cost (LCC) is reduced by 11.94%. The specific energy consumption per square meter is 64kWh/m2 a. [Copyright &y& Elsevier]

Abstract: To mitigate the overheating problem in the warmer seasons, and thereby improve thermal performance and energy efficiency of the double-skin façade (DSF) system, this study introduced an innovative design approach involving the integration of passive thermal mass technique with the air channel of the conventional DSF. To assess the contribution of this integration to energy efficiency of the system, a numerical model was developed, capable of determining the thermal performance of the conventional DSF. The numerical model is composed of airflow and thermal models. This paper briefly describes the development of the models as well as the models’ verifications. Models were then used to carry out a series of parametric studies to investigate the effect of thermal mass on the energy performance of the integrated system. The simulation results revealed that mechanically ventilated DSF can save energy based on configuration from 21% to 26% in summer and from 41% to 59% in winter as compared to conventional DSFs without thermal mass. The results also showed the total saving for a naturally ventilated DSF is negligible year-round. [Copyright &y& Elsevier]

Abstract: The general methodology for estimating energy consumption in buildings, in accordance with the EN ISO 13790, needs the use of constants that are valid for each set of climatic conditions. Furthermore, there are variables other than building structure and weather conditions that have an influence. In this sense, recent research works showed the real effect of permeable coverings on indoor environmental conditions, by controlling indoor moisture. The effect of the associated heat and mass transfer on heating or cooling energy consumption is evident during the initial hours of building occupation. In the present paper, the general methodology of building heat demand calculation is modified to consider different levels of permeability of internal coverings, in order to obtain a more accurate model. Results showed that permeable coverings are related with a higher building utilisation factor, and that the value of this factor is higher in summer than in winter season. Consequently, despite the fact that the sensibility of energy consumption to internal coverings may be lower than to building envelope, new constants are proposed to express a relationship between building permeability and energy consumption, in order to apply the certification equation. [Copyright &y& Elsevier]

Abstract: An Earth-to-Air Heat Exchanger (ETAHE) is a low energy cooling and heating building component. It uses the ground''s thermal storage to dampen ambient air temperature oscillations by delivering the air through a horizontally buried duct. To reduce airflow resistance, some hybrid ventilated buildings have recently adopted large cross-sectional area ducts. This paper describes the development of an Artificial Neural Network based Heat Convection (ANN-HC) algorithm to predict local average Nusselt Numbers along the duct surfaces. Furthermore, the ANN-HC algorithm is integrated with a transient three-dimensional heat transfer model based on finite element analysis of heat conduction in the ground domain surrounding the ETAHE to establish a new thermal modeling method for ETAHEs. A case study is presented to demonstrate the working principle of the new method. It is shown that the method can very well simulate the interactions between an ETAHE and its environment. [Copyright &y& Elsevier]

Abstract: The paper presents an extended method for exergy analysis of buildings and Heating Ventilation Air Conditioning (HVAC) systems, according to an energy demand build-up model from the building side to the energy supply side. The HVAC systems comprise a thermal energy emission and control system, a thermal distribution system, an electricity distribution system and an energy conversion system. Energy and exergy that are required by a building and a HVAC system are posed into the external part and classified by different forms of energy carriers. The external part is out of the boundary of the study. The method is illustrated with an office building equipped with low-temperature heating and high-temperature cooling systems situated in the Netherlands. Thermal exergy and thermal energy demands of the building and thermal energy and thermal exergy losses occurring in the HVAC systems are discussed. The building and the HVAC systems to be considered meet standard Dutch energy performance regulations. Nevertheless their overall exergy efficiencies are low in both cases (17.15% and 6.81% subsequently). The exergy analysis also pinpoints that the thermal energy emission and control system and the energy conversion system are the main causes of the exergy inefficiencies in the heating and cooling cases, respectively. [Copyright &y& Elsevier]

Abstract: Trigeneration systems, also known as Combined Heat, Cooling and Power (CHCP) systems, are interesting alternatives to supply different energy services in urban districts and in large buildings, particularly in warm areas such as Mediterranean countries. These systems can provide substantial benefits from economic, energetic, and environmental viewpoints, since the cogenerated heat can be used for heating in winter as well as cooling in summer with an absorption refrigerator. This paper develops an optimization model using Mixed Integer Linear Programming (MILP) to determine the type, number and capacity of equipment in CHCP systems installed in the tertiary sector as well as to establish the optimal operation mode for the different plant components on an hour-by-hour basis throughout the year. The objective function to be minimized is the annual total cost. The optimization model considers the legal constraints imposed to feed the surplus autogenerated electricity into the grid at a regulated feed-in tariff. The optimization model is applied to design a system providing energy services for a hospital located in the city of Zaragoza (Spain). The effects of the financial market conditions and energy prices in the optimal structure of the system are analyzed. [Copyright &y& Elsevier]

• The DSHP is a valid alternative to both the air and the ground source HP. • A significant reduction in the BHE length can be obtained by the DSHP. • The DSHP has a higher performance leading to a lower electric energy consumption. • The electric energy mix consumption during use plays a key role. Using all phases of a life cycle assessment (LCA), this paper analyses the environmental impact of a dual-source heat pump (DSHP) system that uses either the air or the ground as external heat sources. Data on the production were provided by the manufacturer of the heat pump prototype. The use phase was considered by evaluating the seasonal and annual energy performance of the system, using dynamic simulations. The system maintenance and end-of-life were modelled in accordance with the current regulations and statistical data in this sector. The Ecoinvent database was used as a reference for background data. The ReCiPe, CED and IPCC 100a impact methods were used to assess the environmental impact categories. The results were compared with those of conventional air and ground source heat pump systems. A sensitivity study on the influence of the energy in the use phase was carried out in terms of a variation in energy use and for different energy mixes, including photovoltaic energy. The results demonstrated the environmental validity of the technology in comparison with the two conventional heat pumps used for residential applications in different conditions. The results could be used by heat pump manufacturers to improve the design and performance of their products, by designers in the selection of thermal technologies, and by researchers involved in the study of similar emerging renewable energy technologies. [ABSTRACT FROM AUTHOR]