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Building energy consumption forecasting is crucial for energy managers and policymakers. However, acutely predicting the energy consumption of any building is more important in energy efficiency benchmarking of buildings. Energy benchmarking is a precise technique for measuring, tracking, and reducing end-use energy usage of buildings by employing comparative scenarios. Bottom-Up energy consumption assessment has been used in several studies to evaluate a collection of buildings' energy performance to a standard. Traditionally, researchers have used a single approach to predict the energy use of buildings and to conduct benchmarking. However, it has been found that doing so frequently compromises the accuracy of the predicted energy use of buildings. It also has an adverse effect on the buildings' energy benchmarking framework results. This paper will provide an energy benchmarking framework for residential buildings based on the blending techniques of multiple approaches. Over 3000 datasets were gathered from the Indian city of Jaipur. In order to analyse the trends in energy consumption, the data were divided into categories based on economic levels. The data is then subjected to some fundamental statistical analysis, along with several approaches are blended to forecast the energy consumption of the buildings with the highest accuracy. These benchmark levels set guidelines for assessing and recognising strong performance while also identifying underperforming buildings and giving them more priority for energy efficiency improvement. The technique may be used for different metropolitan levels and climatic conditions. [ABSTRACT FROM AUTHOR]

• Retrofits will be required in 65–85% of covered buildings in most cities. • Heavy (>35%) or deep (>50% savings) energy retrofits will be required in most buildings. • Meeting BPS targets will produce considerable (25–45%) total savings for each city. • Most of the total savings can be achieved by improving a small number of buildings. • Simple payback periods for implementing required retrofits are between 10 and 20 years. Building performance standards (BPS) are a promising policy tool for reducing energy use and greenhouse gas emissions in existing buildings, and have become increasingly popular among major U.S. cities and elsewhere globally. Assessing the scope and extent of the investment required by BPS is critical for shaping their design and preparing jurisdictions for the effort ahead. The goal of this study was to evaluate the feasibility of achieving BPS targets. Municipal benchmarking data for three property types—offices, multifamily housing, and K-12 schools—in 10 U.S. cities was analyzed and compared to the site energy use intensity (EUI) targets in ASHRAE Standard 100–2018. The results show that BPS are a high effort, high reward policy tool with 65–85% of benchmarked buildings not meeting the target and median required reductions of around 30–40% leading to a total energy use reduction of 25–45% for most cities and property types. Median simple payback periods for implementing the required retrofits were estimated between 10 and 20 years. However, the results also show that the majority of BPS savings could be achieved by retrofitting a small number of buildings and these policies could be better tailored to minimize the retrofit effort and maximize the environmental rewards. [ABSTRACT FROM AUTHOR]

Heat pumps and refrigerators are two systems with different usage, but same working principles. Generally, HPs work in steady state condition and specific thermodynamic cycle, but refrigerator or freezer apparatus have variable cycle and work in the unsteady condition. In this study, two different data sources are gathered to analyze thermodynamic differences between two mentioned systems. Initially, an existing heat pump unit is analyzed in different working conditions with different refrigerants and then the unit is converted to a refrigeration device to compare their thermodynamic conditions and treatments. Thermodynamic laws, COP value and efficiency, compressor power consumption, optimum charge amount, and flow rate of secondary fluid are main parameters which are considered to compare heat pump and refrigerator performances by using several refrigerants including R134a, R407c, R22, and R404a. In the case of freezer mode, entropy reduction in compressor and COP L drop to very low values are other substantial issues discussed in this research. It was also revealed that, optimal charge amount of the freezer is 15–25% lower than that of the system when works in HP mode. Experiments showed that, in some cases COP of the heat pump was even more than 100 times greater than that of the freezer. [ABSTRACT FROM AUTHOR]

[Display omitted] • Building policies must be rooted in a good understanding of the targeted population. • Building performance standards may benefit from creating databases of weather files. • A thermal performance analysis should consider multiple key performance indicators. • Building performance policies should address the thermal resilience of buildings. This paper presents the main challenges faced and lessons learned when developing a new method to assess the thermal performance of residential buildings for the recently updated Brazilian building performance standard, NBR 15575–1:2021. It touches on subjects related to the representation of occupant behavior, climate, and thermal acceptability in building performance simulation, as well as the use of reference models, key performance indicators, and performance levels in policies. NBR 15575 provides a thorough procedure to analyze thermal performance, allowing buildings to be assessed while in passive operation mode and also accounting for energy needs when active operation is necessary. Multiple key performance indicators are introduced to provide a comprehensive evaluation. The main difficulty found was dealing with diversity. Given the vast scale of Brazil's territory, a high variation in culture, climate and construction techniques is expected, thus requiring a compromise between detail and scalability. There are still many opportunities for improvement, especially regarding the representation of occupants, and adjustments of the characteristics of reference models to promote high thermal performance, considering the diverse climates, regional practices, and economic needs. This paper might help researchers and other stakeholders to develop and improve other local standards and protocols, especially for warm climates. [ABSTRACT FROM AUTHOR]

Due to the European Union energy reduction strategy, many in-use buildings will be energetically monitored in the coming years to obtain their main thermal characteristics to improve or prove their energy efficiency. This is difficult to do with a reduced set of sensors and a robust data analysis methodology. This paper is focused on proposing some modifications on the existing ISO 9869 method and co-heating method to make them usable with basic energy monitoring data of in-use buildings and obtain their main thermal characteristics: the Heat Loss Coefficient (HLC considers heat losses through envelope plus infiltration) and the solar aperture (S a or gA-value) of the whole building. Under the FP7 project A2PBEER an occupied big office building has been energetically monitored. This monitoring system has been designed and installed while the building was in operation. Using this monitored data a modified ISO 9869 method has been applied to some specifically selected cloudy and cold winter periods to obtain the HLC of the building. Taking this HLC as a reference, a modified co-heating method has been used to estimate both the HLC again and the S a of the whole building. Although monitoring was carried out under very difficult conditions since the building was occupied, the proposed modifications on those two existing methods have delivered very reliable results with these two Key Performance Indicators (HLC and S a ) of the building under real operation conditions. [ABSTRACT FROM AUTHOR]

• A shade net improves thermal performance of the Standard Family Tent (SFT). • The Geodesic Family Tent (GFT) has similar thermal performance to the shaded-SFT. • Practical advantages of the GFT could improve emergency living conditions. Humanitarian tents provide emergency shelter for people displaced by conflict and disaster in diverse climatic conditions. This article compares the thermal performance of two standard humanitarian tents – the Standard Family Tent (SFT) and the Geodesic Family Tent (GFT). The SFT is the most widely used humanitarian shelter, while the GFT was recently introduced as a potential replacement intended to provide, inter-alia , improved thermal performance. The study aims to assess the extent to which this intention is achieved and, in doing so, improve understanding about how tent material and morphology affect thermal performance. Several variables, including internal air temperature, surface temperature, relative humidity and air change rates, were measured and compared in hot and cold conditions. Results demonstrate that the GFT performs better than the SFT regarding radiant heat gain, conductive heat loss and increased air tightness. However, performance of the GFT in relation to heat gain and heat loss is similar to that of the SFT with an additional shade net. Other functional advantages of the GFT are improved structural stability and spaciousness, which, together with improved thermal performance, suggest this marginal innovation in shelter design can positively impact emergency shelter living conditions. [ABSTRACT FROM AUTHOR]

Frequency regulation (FR) is the electric grid service responsible for maintaining the system frequency at its nominal value of 60 Hz in the United States — an indicator of energy balance on the grid. In cases of mismatch between power supply and demand, FR resources either on the generation or the demand side, responding rapidly to restore system frequency to its nominal value. Due to the limited responsiveness of generators, fast and accurate demand side resources (DSR) have recently been encouraged to participate in FR. However, the tested DSRs typically require high initial equipment investment (e.g., flywheels and batteries). Large commercial buildings can provide effective load shaping with little impact to occupants’ comfort and have significant amount of available capacity for FR participation. In addition, commercial buildings are characterized by numerous interdependent HVAC subsystems and control systems. Therefore, a high-level supervisory control strategy is needed that directs the interdependent HVAC systems for FR with strengthened interactions and depressed counteractions. Simulation results suggest that large commercial buildings can provide significant FR capacity and high performance scores. Dynamic building-to-grid integration automatically and continuously provides solutions maintaining energy balance on the gird. The benefit to the power system reliability would be significant. [ABSTRACT FROM AUTHOR]

Abstract: In sub-tropical city of Hong Kong where summer is hot and humid, the usage of outdoor spaces is often hindered due to thermal discomfort. In order to improve the thermal comfort of the outdoor environment and to make urban outdoor spaces delightful places for people to use and enjoy, better understanding of the thermal perception of people is needed. This paper presents the results of an outdoor thermal comfort study conducted in Hong Kong. The findings of the study reveal that air temperature, wind speed and solar radiation intensity are influential factors in determining the thermal sensation of people outdoor. Based on our analysis, the neutral physiological equivalent temperature (PET) in summer in Hong Kong is around 28°C. Under shaded condition, a wind speed of 0.9–1.3m/s is needed for a person in light clothing to achieve neutral thermal sensation in an urban environment. This understanding can contribute towards establishing wind performance standards for thermal comfort in hot and humid tropical and sub-tropical cities. [Copyright &y& Elsevier]

• EU policy efforts on energy efficiency in buildings stared in the 1970s in response to the oil crisis. • The first comprehensive EU policy was the SAVE directive in 1992, introducing policy actions still relevant today. • A major step forward was the Energy Performance of Buildings Directive in 2002 and its subsequent amendments. • Mandatory energy performance standards are progressively converging towards near zero energy buildings. • Additional policies and financing are needed for the full decarbonisation of the building stock. The reduction of energy demand in buildings through the adoption of energy efficiency policy is a key pillar of the European Union (EU) climate and energy strategy. Energy efficiency first emerged in the EU energy policy agenda in the 1970s and was progressively transformed with shifting global and EU energy and climate policies and priorities. The paper offers a review of EU energy policies spanning over the last half century with a focus on policy instruments to encourage measures on energy efficiency in new and existing buildings. Starting from early policies set by the EU in response to the Oil Embargo in the 1973, the paper discusses the impact of EU policies in stimulating energy efficiency improvements in the building sector ranging from the SAVE Directive to the recently 2018 updated Energy Performance of Buildings Directive and Energy Efficiency Directive. The review explores the progress made over the last 50 years in addressing energy efficiency in buildings and highlights successes as well as remaining challenges. It discusses the impact of political priorities in reshaping how energy efficiency is addressed by EU policymakers, leading to a holistic approach to buildings, and provides insights and suggestions on how to further exploit the EU potential to save energy from buildings. [ABSTRACT FROM AUTHOR]