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The air quality in classrooms significantly impacts school children's health and learning performance. It has been reported worldwide that classroom air quality does not meet the required standard and actions are pledged for improvement. However, it poses a challenge for decision-making in terms of prioritising taking-up measures. The aim of this study is to propose a method of identifying the action measures for improving classroom air quality and prioritising them. Case studies in the UK and China were conducted, and the key measures were identified through literature studies, open-ended questionnaire surveys, and workshop discussions, which are classified into three categories: B1, policy; B2, technology; and B3, information sharing. The analytical hierarchy process (AHP) is applied in the prioritisation of the action measures. A total of 138 teachers and parents from China and the UK participated in this case study. The genetic algorithm-optimised Hadamard product (GAOHP) method is applied to justify the consistency ratio (CR) within the required threshold value in order to ensure the consistency of the subjective perception and the accuracy of comparative weights. The results show that item B2, technology, is the most desired measure by both Chinese and British parents and teachers, despite the deviation from the optimal choice in China and the UK. Among the proposed action measures, the UK respondents strongly expected air purifiers with natural ventilation as opposed to their Chinese counterparts preferring to share the real-time status of classroom air quality. Our work will provide strong support for the subsequent selection of indoor air quality improvement strategies for schools. [ABSTRACT FROM AUTHOR]

Building occupancy patterns are an important factor in considering the energy efficiency of buildings and a key input for building performance modelling. More specifically, the energy consumption associated with heating, cooling, lighting, and plug load usage depends on the number of occupants in a building. Identifying occupancy patterns and profiles in buildings is a key factor for the optimisation of building operating systems and can potentially reduce the performance gap between the planning stage and the actual energy usage. This study aims to identify the patterns and profiles of the occupants in a selected case study building in England. In this study, occupancy data were collected over 12 months at five minutes intervals. A sensor was used to obtain high accuracy occupancy data compared to previous studies that encountered uncertainties in data collection. A set of clustering analyses was carried out to identify occupancy patterns and profiles in the building. The results of this study identified three different occupancy patterns and profiles as well as four drivers that influenced the occupants in the case study building: the beginning of the academic term, the examination period, the weekday/weekends, and the vacation driver. [ABSTRACT FROM AUTHOR]

In response to the call for global carbon peaking and neutrality, this study mainly focuses on the comparison of energy-related carbon emissions and the performance of two promising heating, ventilation, and air-conditioning technologies (a ground source heat pump (GSHP) and cogeneration systems) over both short (2021–2030) and long (2031–2050) periods, considering the UK decarbonization plans. The simulation model of the building with the GSHP system is validated by the actual building heating energy data in 2020 and 2021, with yearly deviations of only 0.4–0.5%. The results show that the cogeneration system performed better than the GSHP system in a scenario when there was no electricity decarbonization plan in the future. However, under all of the MARKet ALlocation (MARKAL) scenarios, the GSHP system performed much better than the cogeneration system in terms of carbon reduction in both periods, which can achieve 47.8–84.4% and maximum 97.5% carbon emission savings in short and long-term periods, respectively, compared with the cogeneration system. Due to the truth that electricity decarbonization plans will be optimized and executed in the future, the GSHP system is more promising and recommended compared with cogeneration system in both short- and long-term periods in terms of only decarbonization potentials (e.g., reducing carbon emission and achieving carbon-related environmental protection). [ABSTRACT FROM AUTHOR]

Offsite prefabrication (OP) is an important approach in overcoming some inefficiencies in the U.K. construction sector. Whilst growth in OP can be demonstrated, its uptake is limited in relation to the expected benefit of its application. Perception, in part due to historical application, has been highlighted as a significant contributing factor in its limited uptake. However, despite recognition that the uncertainties associated with perception on OP are important to technological innovation adoption, these uncertainties were not explored in the previous studies. We adopt fuzzy-set theory, in combination with a survey from 76 organisations in the U.K., to explore these uncertainties in perception for a broad range of OP applications. Through fuzzy-set analysis, the study presents insight into some of the uncertainties related to the perception of OP through three themes: Uptake, Impression, and Strategy. This study proposes that the uncertainty in the perception of OP value, within specific and across all applications, needs to be explicitly considered to understand how perception is informing uptake. This research also suggests that negative perception is one of the key constraints to uptake and it is in fact the overall culture of the U.K. construction sector that is limiting the uptake of OP. [ABSTRACT FROM AUTHOR]

Buildings account for more than 40% of total energy consumption in most countries and more than 55% of this energy is used by heating, ventilation, air-conditioning and refrigeration (HVAC&R) systems. This significant energy demand, together with the global need to impose energy-efficiency measures, underlines the importance of selecting the most appropriate HVAC&R system in the early stages of a design process. However, this state-of-the-art study reveals that there is no review paper available in the open literature to critically analyse the existing methods for HVAC&R systems selection. Therefore, the aim of this paper is to critically review the body of knowledge on the adopted approach for HVAC&R systems selection. Based on the comprehensive literature review, the needs and gaps in this field are identified. It is revealed that the integration of probabilistic climate changes into the decision-making processes is one of the main areas that should be addressed in future studies. In addition, reliability and Life Cycle Cost of the systems, health and well-being, occupants’ satisfaction and indoor air quality are of paramount factors that should be taken into account in the decision-making process for HVAC&R systems selection. [ABSTRACT FROM AUTHOR]

Research on the performance gap suggests that the actual energy consumption in buildings can be twice as much as expected from modelled estimates. Energy models rely on predictive indicators and assumptions that are usually done at the design stage, without acknowledging behavioral patterns of actual users, amongst other uncertain elements. Moreover, in the context of the performance gap, it is evident that energy efficiency is overemphasized while other key issues such as health and comfort of occupants associated with indoor air quality, noise levels etc., have been less stressed and discussed. This paper discusses physical measurements of indoor temperature in a case study building at the University of Cambridge and reports findings of a workshop with researchers, building professionals and graduate students working on environmental performance in the built environment. The workshop addressed research issues related to energy, comfort and health (couched in terms of thermal performance), used as a means to understand the complexities of and trade-off between different aspects of sustainable buildings. Retrofit measures were suggested while considering how to balance energy and comfort needs, with some these measures being modelled to determine their efficacy. This research concludes with a reflection on how to implement these retrofit measures in a manner that addresses the performance gap. [ABSTRACT FROM AUTHOR]

The modern built environment has become more complex in terms of building types, environmental systems and use profiles. This complexity causes difficulties in terms of optimizing buildings energy design. In this circumstance, introducing a set of prototypical reference buildings, or so-called benchmark buildings, that are able to represent all or majority parts of the UK building stock may be useful for examination of the effect of national energy policies on building energy consumption. This study proposes a set of reference office buildings for England and Wales based on the information collected from the Non-Domestic Building Stock project and an intensive review of the existing building benchmarks. The proposed building benchmark comprises of 10 prototypical reference buildings, which in relation to built form and size, represent 95% of office buildings in England and Wales. This building benchmark provides a platform for those involved in building energy simulations to evaluate energy-efficiency measures and for policymakers to assess the influence of different building energy policies. [ABSTRACT FROM AUTHOR]

Highlights: [•] Performance of 36 primary and secondary HVAC&R systems is investigated. [•] Energy consumption, CO2 emissions, thermal comfort and indoor air quality are examined. [•] Despite the higher energy consumption, CCHP system has the lowest total CO2 emissions. [•] The outcomes form a robust basis for HVAC&R system performance benchmarks. [Copyright &y& Elsevier]

It is important to reduce primary energy consumption and greenhouse gas emissions associated with residential buildings in the hot summer and cold winter (HSCW) zone of China. Changing the insulation thickness of the external walls of residential buildings (ITEWB) is regarded as an effective way to manage such problems within a budget. This paper aims at developing an innovative way to select the optimal insulation thickness of external walls for residential buildings (OTWRB) in the HSCW zone of China, considering economic, energy and greenhouse gas emissions issues associated with the ITEWB. Four different cities and two different operation modes of the air conditioners (continuous and intermittent) are considered in this study. To explain the selection process, typical hypothetical buildings are simulated in Wuhan, Changsha, Hangzhou and Chengdu. Expanded polystyrene is chosen as the material of the insulation layer while split air conditioners are selected as the equipment for space heating and cooling. Integrated Environmental Solutions-Virtual Environment is used for the dynamic operational energy consumption of buildings. Life cycle cost method is adopted to calculate the economic impact of ITEWB on building performance. The Chinese life cycle database is used to quantize the impacts of ITEWB on building performance in the aspect of energy and greenhouse gas emissions based on the life cycle theory. The most appreciated insulation thickness is chosen from the thickness range of 30 mm to 150 mm. We find that for continuous operation mode of air conditioners in Wuhan, the optimal economic insulation thickness is 70 mm, whereas when considering only energy and environmental aspects, the OTWRB is 150 mm. These are all larger than the current insulation thickness which is 30 mm. When the weighting efficiencies of the economy, energy, and greenhouse gas emissions are different, the OTWRB varies from 70 mm to 150 mm for continuous operation mode. The different cities have little influence on the OTWRB while the different operation modes of air conditioners have some influence on the OTWRB. [ABSTRACT FROM AUTHOR]