Pub Date : 2025-02-04DOI: 10.1016/j.enbuild.2025.115421
Zhaoping Wu , Yandong Tan , Kai Fang , Xu Wu , Ying Ge , Jie Chang
Urban energy metabolism plays a pivotal role in determining the energy efficiency of cities, and is intrinsically linked to economic and environmental sustainability, as well as human well-being. However, the general principles underlying urban energy metabolism are poorly explored, which are needed for devising effective energy management solutions for future urbanization challenges. Drawing inspiration from the scaling laws observed in biological metabolism, an empirical model is introduced in this study to reveal the relationship between urban energy metabolism and urban mass. By analyzing 60 cities in China, we first developed a bottom-up framework for identifying city components and measured urban mass, then explored the scaling laws of urban energy metabolism response to urban mass. Results show that: (1) urban energy metabolism scales linearly (β ∼ 1) with population size, but its response to urban mass shifts from sublinear to linear scaling as economic level raised; (2) superlinear scaling behavior in GDP output (β > 1) promote energy efficiency of larger cities; (3) high-economic city group shows a linear scaling in energy metabolism with urban mass, aligning with that of unicellular eukaryotes; (4) economic level is the most significant factor affecting energy efficiency of cities. (5) urban energy metabolism’s strong link to building mass implies a priority for energy-efficient buildings. Our analysis demonstrates that modern cities share the common scaling principle in energy metabolism with unicellular eukaryotes and provides a methodology for city planning and management by learning from more evolved eukaryotic cells, which could define better strategies to enhance the sustainability and vitality of global cities.
{"title":"Scaling laws of energy metabolism in modern cities: Insights from biological metabolism","authors":"Zhaoping Wu , Yandong Tan , Kai Fang , Xu Wu , Ying Ge , Jie Chang","doi":"10.1016/j.enbuild.2025.115421","DOIUrl":"10.1016/j.enbuild.2025.115421","url":null,"abstract":"<div><div>Urban energy metabolism plays a pivotal role in determining the energy efficiency of cities, and is intrinsically linked to economic and environmental sustainability, as well as human well-being. However, the general principles underlying urban energy metabolism are poorly explored, which are needed for devising effective energy management solutions for future urbanization challenges. Drawing inspiration from the scaling laws observed in biological metabolism, an empirical model is introduced in this study to reveal the relationship between urban energy metabolism and urban mass. By analyzing 60 cities in China, we first developed a bottom-up framework for identifying city components and measured urban mass, then explored the scaling laws of urban energy metabolism response to urban mass. Results show that: (1) urban energy metabolism scales linearly (β ∼ 1) with population size, but its response to urban mass shifts from sublinear to linear scaling as economic level raised; (2) superlinear scaling behavior in GDP output (β > 1) promote energy efficiency of larger cities; (3) high-economic city group shows a linear scaling in energy metabolism with urban mass, aligning with that of unicellular eukaryotes; (4) economic level is the most significant factor affecting energy efficiency of cities. (5) urban energy metabolism’s strong link to building mass implies a priority for energy-efficient buildings. Our analysis demonstrates that modern cities share the common scaling principle in energy metabolism with unicellular eukaryotes and provides a methodology for city planning and management by learning from more evolved eukaryotic cells, which could define better strategies to enhance the sustainability and vitality of global cities.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"332 ","pages":"Article 115421"},"PeriodicalIF":6.6,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-04DOI: 10.1016/j.enbuild.2025.115423
Ang Wang , Shao-Cong Wang , Fan Peng , Jie Xia , Hui Ren , Mei-Lan Tan , Bin Zhou
The heating, ventilation and air conditioning (HVAC) system in the operating room is designed to provide clean air and reduce surgical site infection rates. Although the HVAC system provides a good indoor thermal environment for the surgical team and patients, the different thermal preferences of the surgical team pose challenges to meet the general comfort requirements. Therefore, we conducted a field survey on the thermal environment and thermal comfort of the operating room in Nanjing, and collected 254 questionnaires. The survey results show that the thermal comfort of personnel is related to the class of operating room and work responsibilities. It is shown that only 18.2 % of the medical staff said that the thermal environment in the operating room had no effect on the operation process. 22.7 % of the staff said that the thermal environment in the operating room affected the operation and needed to be improved. The thermal comfort level of the circulating nurse was better. The surgeon felt hot, while the anesthesiologist felt cold. The difference of medical staff’s responsibilities leads to the difference of thermal comfort. As the cleanliness level of the operating room decreases, the thermal comfort level of the medical staff increases. This study provides a basis for improving the thermal environment of the surgical team in the operating room.
{"title":"Field questionnaire survey on thermal comfort of medical personnel in operating rooms for hospitals in Nanjing","authors":"Ang Wang , Shao-Cong Wang , Fan Peng , Jie Xia , Hui Ren , Mei-Lan Tan , Bin Zhou","doi":"10.1016/j.enbuild.2025.115423","DOIUrl":"10.1016/j.enbuild.2025.115423","url":null,"abstract":"<div><div>The heating, ventilation and air conditioning (HVAC) system in the operating room is designed to provide clean air and reduce surgical site infection rates. Although the HVAC system provides a good indoor thermal environment for the surgical team and patients, the different thermal preferences of the surgical team pose challenges to meet the general comfort requirements. Therefore, we conducted a field survey on the thermal environment and thermal comfort of the operating room in Nanjing, and collected 254 questionnaires. The survey results show that the thermal comfort of personnel is related to the class of operating room and work responsibilities. It is shown that only 18.2 % of the medical staff said that the thermal environment in the operating room had no effect on the operation process. 22.7 % of the staff said that the thermal environment in the operating room affected the operation and needed to be improved. The thermal comfort level of the circulating nurse was better. The surgeon felt hot, while the anesthesiologist felt cold. The difference of medical staff’s responsibilities leads to the difference of thermal comfort. As the cleanliness level of the operating room decreases, the thermal comfort level of the medical staff increases. This study provides a basis for improving the thermal environment of the surgical team in the operating room.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"332 ","pages":"Article 115423"},"PeriodicalIF":6.6,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-04DOI: 10.1016/j.enbuild.2025.115348
Corinne Chaton
Most EU countries have introduced financial and fiscal instruments to accelerate investment in the energy renovation of buildings, which is needed to achieve carbon neutrality by 2050. However, in the absence of reliable data, it is difficult for some countries, such as France, to assess the impact of these instruments on both the dynamics of energy renovation and fuel poverty. To compensate for this lack of data, a tool has been developed. It is presented in this study. It takes into account the three predominant factors in the notion of fuel poverty, namely household resources, the price of energy and the quality of housing. It includes two multiple linear models for estimating: 1. disposable income and 2. energy expenditure. A life-cycle investment cost model is used to calculate the probability of an owner-occupier carrying out thermal renovation work. For tenant households, renovation is based on an annual renovation target. The model is tested in the French case with real values for variations in energy prices and disposable income. It has been calibrated to reproduce the distribution of dwellings according to their energy performance in 2017. The effects of different renovation subsidies on the dynamics of renovation and on fuel poverty are studied. Among the results of the simulations, it should be emphasised that financing the renovation of the least energy-efficient homes alone is not the most effective solution for reducing fuel poverty.
{"title":"Impact of public policies on the dynamics of energy retrofit and fuel poverty in mainland France","authors":"Corinne Chaton","doi":"10.1016/j.enbuild.2025.115348","DOIUrl":"10.1016/j.enbuild.2025.115348","url":null,"abstract":"<div><div>Most EU countries have introduced financial and fiscal instruments to accelerate investment in the energy renovation of buildings, which is needed to achieve carbon neutrality by 2050. However, in the absence of reliable data, it is difficult for some countries, such as France, to assess the impact of these instruments on both the dynamics of energy renovation and fuel poverty. To compensate for this lack of data, a tool has been developed. It is presented in this study. It takes into account the three predominant factors in the notion of fuel poverty, namely household resources, the price of energy and the quality of housing. It includes two multiple linear models for estimating: 1. disposable income and 2. energy expenditure. A life-cycle investment cost model is used to calculate the probability of an owner-occupier carrying out thermal renovation work. For tenant households, renovation is based on an annual renovation target. The model is tested in the French case with real values for variations in energy prices and disposable income. It has been calibrated to reproduce the distribution of dwellings according to their energy performance in 2017. The effects of different renovation subsidies on the dynamics of renovation and on fuel poverty are studied. Among the results of the simulations, it should be emphasised that financing the renovation of the least energy-efficient homes alone is not the most effective solution for reducing fuel poverty.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"332 ","pages":"Article 115348"},"PeriodicalIF":6.6,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-04DOI: 10.1016/j.enbuild.2025.115429
Guoqing Yu, Runnan Lu, Xing Lv, Shuang Feng
Limited research has explored the relationship between skin heat flux and thermal sensation. While prior models by Hui Zhang and Yuming Sun addressed thermal comfort, they were unsuitable for personalized heating microenvironments. This study examines changes in local thermal sensation, skin temperature, and heat flux in such settings. Experiments measured local skin temperature, heat flux, and thermal sensation using questionnaire surveys. By analyzing relationships among these variables, separate models were developed for three lower body parts—thigh, calf, and sole—accounting for gender differences. The mathematical models established for local thermal sensation and skin temperature were expressed as segmented exponential functions, while heat flux and thermal sensation exhibited a negative exponential correlation. The proposed models demonstrated enhanced alignment with experimental results, improving accuracy by 85.37 % in personalized heating microenvironments. Additionally, gender differences significantly influenced the models, particularly for the sole. These findings advance the accuracy of thermal comfort predictions and provide a robust framework for analyzing thermal environments.
{"title":"Local thermal sensation model with local skin temperature and local skin heat flux in a personalized heating microenvironment","authors":"Guoqing Yu, Runnan Lu, Xing Lv, Shuang Feng","doi":"10.1016/j.enbuild.2025.115429","DOIUrl":"10.1016/j.enbuild.2025.115429","url":null,"abstract":"<div><div>Limited research has explored the relationship between skin heat flux and thermal sensation. While prior models by Hui Zhang and Yuming Sun addressed thermal comfort, they were unsuitable for personalized heating microenvironments. This study examines changes in local thermal sensation, skin temperature, and heat flux in such settings. Experiments measured local skin temperature, heat flux, and thermal sensation using questionnaire surveys. By analyzing relationships among these variables, separate models were developed for three lower body parts—thigh, calf, and sole—accounting for gender differences. The mathematical models established for local thermal sensation and skin temperature were expressed as segmented exponential functions, while heat flux and thermal sensation exhibited a negative exponential correlation. The proposed models demonstrated enhanced alignment with experimental results, improving accuracy by 85.37 % in personalized heating microenvironments. Additionally, gender differences significantly influenced the models, particularly for the sole. These findings advance the accuracy of thermal comfort predictions and provide a robust framework for analyzing thermal environments.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"332 ","pages":"Article 115429"},"PeriodicalIF":6.6,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present research work develops a new approach for the optimization of thermostat setting and insulation designs in residential buildings located in various Iranian climates, including hot-humid, arid, temperate, and cool regions. The objective functions are set to minimize the construction cost, consumed electricity cost, and PPD to improve thermal comfort. Advanced computational techniques are integrated in a structured way to achieve the mentioned objectives. Numerical modeling is done through the simulation of building energy performance and thermal comfort using EnergyPlus. The exact mathematical relations between design variables and objective functions, which were heating setpoint and cooling setpoint, insulation thickness, and thermal conductivity, were identified using Multi-Polynomial Regression. MPR model has been validated respect to a wide set of statistical measures that included but were not limited to R², RMSE, and MAE for its high predictive accuracy. Then, multi-objective optimization is performed through NSGA-II, a well-known multi-objective optimization algorithm, which provides a Pareto front of optimal solutions balancing energy efficiency, cost, and comfort. Shannon's entropy method assigns weights to the Pareto-optimal solutions, whereas the Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS) selects the most suitable configurations for each city. Calculations show a great reduction in energy consumption to up to 82.66% at Bandar Abbas, with very important improvements in comfort, where the PPD is reduced between 31.1% to 56.3%. The predictive capacity of the MPR model was confirmed by this study, from the value of R², close to 1. The cost-effectiveness of the proposed solutions is underlined by minimizing construction and energy costs while preserving occupant comfort. This innovative approach adapts optimization strategies to regional climatic characteristics, providing practical solutions for sustainable and cost-effective building designs. The integration of advanced machine learning and genetic algorithms offers a scalable framework for future energy-efficient construction practices worldwide, contributing to reduced carbon footprints and enhanced occupant well-being. By addressing the limitations of previous studies and introducing a clear, structured methodology, this research provides valuable insights and practical tools for optimizing residential building performance in diverse climates.
{"title":"Optimizing the thermostat setting points of residential and insulated buildings in the direction of economic efficiency and thermal comfort through advanced multi-purpose techniques","authors":"Peng He , Ali B.M. Ali , Zahraa Abed Hussein , Narinderjit Singh Sawaran Singh , Pardeep Singh Bains , Shaxnoza Saydaxmetova , Mohammadreza Baghoolizadeh , Soheil Salahshour , As’ad Alizadeh","doi":"10.1016/j.enbuild.2025.115428","DOIUrl":"10.1016/j.enbuild.2025.115428","url":null,"abstract":"<div><div>The present research work develops a new approach for the optimization of thermostat setting and insulation designs in residential buildings located in various Iranian climates, including hot-humid, arid, temperate, and cool regions. The objective functions are set to minimize the construction cost, consumed electricity cost, and PPD to improve thermal comfort. Advanced computational techniques are integrated in a structured way to achieve the mentioned objectives. Numerical modeling is done through the simulation of building energy performance and thermal comfort using EnergyPlus. The exact mathematical relations between design variables and objective functions, which were heating setpoint and cooling setpoint, insulation thickness, and thermal conductivity, were identified using Multi-Polynomial Regression. MPR model has been validated respect to a wide set of statistical measures that included but were not limited to R², RMSE, and MAE for its high predictive accuracy. Then, multi-objective optimization is performed through NSGA-II, a well-known multi-objective optimization algorithm, which provides a Pareto front of optimal solutions balancing energy efficiency, cost, and comfort. Shannon's entropy method assigns weights to the Pareto-optimal solutions, whereas the Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS) selects the most suitable configurations for each city. Calculations show a great reduction in energy consumption to up to 82.66% at Bandar Abbas, with very important improvements in comfort, where the PPD is reduced between 31.1% to 56.3%. The predictive capacity of the MPR model was confirmed by this study, from the value of R², close to 1. The cost-effectiveness of the proposed solutions is underlined by minimizing construction and energy costs while preserving occupant comfort. This innovative approach adapts optimization strategies to regional climatic characteristics, providing practical solutions for sustainable and cost-effective building designs. The integration of advanced machine learning and genetic algorithms offers a scalable framework for future energy-efficient construction practices worldwide, contributing to reduced carbon footprints and enhanced occupant well-being. By addressing the limitations of previous studies and introducing a clear, structured methodology, this research provides valuable insights and practical tools for optimizing residential building performance in diverse climates.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"332 ","pages":"Article 115428"},"PeriodicalIF":6.6,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-02DOI: 10.1016/j.enbuild.2025.115403
Tangjun Feng , Ran Peng
This study aims to identify outdoor thermal comfort and the cooling effect among different layouts of shaded spaces for the humid subtropical (Cfa) climatic zones in Guangzhou, China. Six shaded spaces with one unshaded space were investigated by using meteorological measurements and questionnaire surveys during summer and winter. Outdoor thermal benchmarks were determined with Physiological Equivalent Temperature (PET) and compared with other climatic zones. The thermal comfort calendar for shaded spaces was proposed and the thermal adaptation behaviors were summarized. Results showed that: 1) Deciduous tree array provided the best cooling effect of 4.7 ℃ (Ta) and 11.3 ℃ (PET) in summer, and 4.6 ℃ (Ta) and 8.0 ℃ (PET) in winter (warm period). 2) the single row of evergreen trees was deemed as the most comfortable space during summer and winter, despite receiving low thermal sensation votes for “neutral” in summer. 3) Air temperature and global temperature were the main factors influencing outdoor thermal comfort. 4) The neutral PET, the PET range, the PET acceptability range and the preferred PET in Guangzhou were 18.4 ℃, 11.9–24.8 ℃, 8.3–22 ℃ and 18.2 ℃, respectively. 5) All shaded spaces were “moderate heat stress” after 12:00 or warmer in summer, and lake pavilion experienced “moderate heat stress” from 10:00 to 14:00 on sunny days in the winter warm period. These results could help urban designers and planners gain insights into the outdoor thermal comfort and adaptive behaviors of Guangzhou people, evaluate the varying cooling effect in different layouts of shaded spaces, and select suitable thermal benchmarks and appropriate configurations to create thermally comfortable outdoor shaded spaces in humid subtropical urban parks.
{"title":"Outdoor thermal comfort and the cooling effect in different layouts of shaded spaces: A study of Guangzhou, China","authors":"Tangjun Feng , Ran Peng","doi":"10.1016/j.enbuild.2025.115403","DOIUrl":"10.1016/j.enbuild.2025.115403","url":null,"abstract":"<div><div>This study aims to identify outdoor thermal comfort and the cooling effect among different layouts of shaded spaces for the humid subtropical (Cfa) climatic zones in Guangzhou, China. Six shaded spaces with one unshaded space were investigated by using meteorological measurements and questionnaire surveys during summer and winter. Outdoor thermal benchmarks were determined with Physiological Equivalent Temperature (PET) and compared with other climatic zones. The thermal comfort calendar for shaded spaces was proposed and the thermal adaptation behaviors were summarized. Results showed that: 1) Deciduous tree array provided the best cooling effect of 4.7 ℃ (T<sub>a</sub>) and 11.3 ℃ (PET) in summer, and 4.6 ℃ (T<sub>a</sub>) and 8.0 ℃ (PET) in winter (warm period). 2) the single row of evergreen trees was deemed as the most comfortable space during summer and winter, despite receiving low thermal sensation votes for “neutral” in summer. 3) Air temperature and global temperature were the main factors influencing outdoor thermal comfort. 4) The neutral PET, the PET range, the PET acceptability range and the preferred PET in Guangzhou were 18.4 ℃, 11.9–24.8 ℃, 8.3–22 ℃ and 18.2 ℃, respectively. 5) All shaded spaces were “moderate heat stress” after 12:00 or warmer in summer, and lake pavilion experienced “moderate heat stress” from 10:00 to 14:00 on sunny days in the winter warm period. These results could help urban designers and planners gain insights into the outdoor thermal comfort and adaptive behaviors of Guangzhou people, evaluate the varying cooling effect in different layouts of shaded spaces, and select suitable thermal benchmarks and appropriate configurations to create thermally comfortable outdoor shaded spaces in humid subtropical urban parks.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"331 ","pages":"Article 115403"},"PeriodicalIF":6.6,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143219822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-02DOI: 10.1016/j.enbuild.2025.115408
Jingchuan Deng , Xinsheng Wang , Fangang Meng
With the development of building power supply technology, traditional building is gradually replaced by smart building (SB) with advanced energy management system, enabling effective management of building energy resources. However, the uncertainty of photovoltaic (PV) output brings new challenges to building energy management. Therefore, this paper proposes a multi-agent deep reinforcement learning-based energy management strategy for SB, in which SB is decomposed into multiple energy-local area networks (E-LANs) with controllable devices, each E-LAN is then regarded as an agent. According to the multi-agent deep deterministic policy gradient algorithm, each agent learns the optimal energy management strategy for E-LAN through interactions with the environment, thereby achieving overall energy management for SB. To fully account for the uncertainty of PV outputs, first, random PV output time sequences are used during training process of algorithm. Then, the equivalent PV output is obtained according to the converted deterministic constraints from the joint chance constraint of the original problem, and is used for solving the day-ahead energy management. Simulation results show that compared to stochastic programming-based method and deep deterministic policy gradient algorithm-based method, the proposed energy management method reduces the total cost by up to 11.5% within a scheduling period and by up to 7.6% in 3 continuous scheduling period. Additionally, energy interaction between E-LANs is improved significantly to promote local energy consumption.
{"title":"Multi-agent deep reinforcement learning for Smart building energy management with chance constraints","authors":"Jingchuan Deng , Xinsheng Wang , Fangang Meng","doi":"10.1016/j.enbuild.2025.115408","DOIUrl":"10.1016/j.enbuild.2025.115408","url":null,"abstract":"<div><div>With the development of building power supply technology, traditional building is gradually replaced by smart building (SB) with advanced energy management system, enabling effective management of building energy resources. However, the uncertainty of photovoltaic (PV) output brings new challenges to building energy management. Therefore, this paper proposes a multi-agent deep reinforcement learning-based energy management strategy for SB, in which SB is decomposed into multiple energy-local area networks (E-LANs) with controllable devices, each E-LAN is then regarded as an agent. According to the multi-agent deep deterministic policy gradient algorithm, each agent learns the optimal energy management strategy for E-LAN through interactions with the environment, thereby achieving overall energy management for SB. To fully account for the uncertainty of PV outputs, first, random PV output time sequences are used during training process of algorithm. Then, the equivalent PV output is obtained according to the converted deterministic constraints from the joint chance constraint of the original problem, and is used for solving the day-ahead energy management. Simulation results show that compared to stochastic programming-based method and deep deterministic policy gradient algorithm-based method, the proposed energy management method reduces the total cost by up to 11.5% within a scheduling period and by up to 7.6% in 3 continuous scheduling period. Additionally, energy interaction between E-LANs is improved significantly to promote local energy consumption.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"331 ","pages":"Article 115408"},"PeriodicalIF":6.6,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143219824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-02DOI: 10.1016/j.enbuild.2025.115418
Zhuqing Luo, Hongtao Xu
The application of phase change materials in building envelopes has shown great potential to reduce energy consumption. However, current research is typically limited to short-term experimental data (1–3 day s) or data obtained from a small number of measurement points, and lack monitoring of the thermal behavior of phase change materials, which are insufficient to provide a reliable basis for practical applications. This study addresses this gap by constructing two outdoor huts in Shanghai. Both huts equipped with fan heaters controlled by temperature controller to maintain appropriate indoor temperature. One of the huts integrated phase change material into the hollow polycarbonate sheets and porous bricks for the roof and walls, respectively. Over 15 days in April, an in-depth analysis was conducted on the long-term thermal response of the phase change material, roof, and walls, the operational details, and electricity consumption of two fan heaters in both huts to assess the impact of phase change material on thermal performance and building operational energy consumption. Results indicate that applying phase change material significantly improved thermal stability of walls, reducing the average daily amplitude of temperature fluctuations within walls from 6.9–7.3 °C to 5.4–6.0 °C. The phase change material at different positions showed positive effects over a long period, with the roof application delaying the occurrence of peak temperature in the hollow polycarbonate sheet holes by an average of 62 min daily. The paraffin wax on the north wall exhibited optimal performance, maintaining effective thermal regulation for 18.4–24 h before April 14th. Additionally, the integration of phase change material-enhanced energy efficiency, resulting in a 27.8 % reduction in electricity consumption. This study investigated the energy storage behavior of phase change material in various building locations under the combined effects of the outdoor environment and fan heater over 15 days, contributing to enhanced energy performance of building during transitional seasons.
{"title":"An experimental study on thermal performance Characteristics of a hut enhanced by phase change material in Shanghai","authors":"Zhuqing Luo, Hongtao Xu","doi":"10.1016/j.enbuild.2025.115418","DOIUrl":"10.1016/j.enbuild.2025.115418","url":null,"abstract":"<div><div>The application of phase change materials in building envelopes has shown great potential to reduce energy consumption. However, current research is typically limited to short-term experimental data (1–3 day s) or data obtained from a small number of measurement points, and lack monitoring of the thermal behavior of phase change materials, which are insufficient to provide a reliable basis for practical applications. This study addresses this gap by constructing two outdoor huts in Shanghai. Both huts equipped with fan heaters controlled by temperature controller to maintain appropriate indoor temperature. One of the huts integrated phase change material into the hollow polycarbonate sheets and porous bricks for the roof and walls, respectively. Over 15 days in April, an in-depth analysis was conducted on the long-term thermal response of the phase change material, roof, and walls, the operational details, and electricity consumption of two fan heaters in both huts to assess the impact of phase change material on thermal performance and building operational energy consumption. Results indicate that applying phase change material significantly improved thermal stability of walls, reducing the average daily amplitude of temperature fluctuations within walls from 6.9–7.3 °C to 5.4–6.0 °C. The phase change material at different positions showed positive effects over a long period, with the roof application delaying the occurrence of peak temperature in the hollow polycarbonate sheet holes by an average of 62 min daily. The paraffin wax on the north wall exhibited optimal performance, maintaining effective thermal regulation for 18.4–24 h before April 14th. Additionally, the integration of phase change material-enhanced energy efficiency, resulting in a 27.8 % reduction in electricity consumption. This study investigated the energy storage behavior of phase change material in various building locations under the combined effects of the outdoor environment and fan heater over 15 days, contributing to enhanced energy performance of building during transitional seasons.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"331 ","pages":"Article 115418"},"PeriodicalIF":6.6,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143219821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.enbuild.2024.115200
Mingwu Tang , Xiaozhou Wu , Yunfeng Wang , Dong Liu , Jun Wang , Zhong Li , Airong Feng , Xiangli Li
Prefabricated ceiling radiant panel is one type of efficient and lightweight radiant heating and cooling terminal, which has been widely used in many commercial and residential buildings. The surface temperature distribution of radiant terminal is a crucial factor that affects the local thermal discomfort for heating and the surface condensation risk for cooling. However, the existing research on surface temperature distribution lacked a correlation with the average surface temperature prediction model, which was not convenient for guiding the design and control of radiant heating and cooling systems. Therefore, this paper proposed a new simplified model of radiant panels, and the calculation errors of heat transfer and average surface temperature were within ±5 % and ±1 %, respectively. Furthermore, a surface temperature distribution prediction model was established, and the definition of surface temperature uniformity was also determined through derivation. The calculation results indicated that the root mean square error between the predicted surface temperatures at each measurement point and experimental values was 0.8 °C for heating and 0.4 °C for cooling, and the corresponding relative errors of surface temperature uniformity were 5.7 % and 8.9 %. Finally, the effects of water supply temperature, water mass flow rate, pipe spacing, pipe diameter and thickness of heat distribution plate on the surface temperature distribution were quantitatively analyzed. The results showed that the water mass flow rate, pipe spacing (more than 150 mm) and the thickness of the heat distribution plate clearly influenced the surface temperature uniformity.
{"title":"Surface temperature distribution prediction model for prefabricated ceiling radiant panel","authors":"Mingwu Tang , Xiaozhou Wu , Yunfeng Wang , Dong Liu , Jun Wang , Zhong Li , Airong Feng , Xiangli Li","doi":"10.1016/j.enbuild.2024.115200","DOIUrl":"10.1016/j.enbuild.2024.115200","url":null,"abstract":"<div><div>Prefabricated ceiling radiant panel is one type of efficient and lightweight radiant heating and cooling terminal, which has been widely used in many commercial and residential buildings. The surface temperature distribution of radiant terminal is a crucial factor that affects the local thermal discomfort for heating and the surface condensation risk for cooling. However, the existing research on surface temperature distribution lacked a correlation with the average surface temperature prediction model, which was not convenient for guiding the design and control of radiant heating and cooling systems. Therefore, this paper proposed a new simplified model of radiant panels, and the calculation errors of heat transfer and average surface temperature were within ±5 % and ±1 %, respectively. Furthermore, a surface temperature distribution prediction model was established, and the definition of surface temperature uniformity was also determined through derivation. The calculation results indicated that the root mean square error between the predicted surface temperatures at each measurement point and experimental values was 0.8 °C for heating and 0.4 °C for cooling, and the corresponding relative errors of surface temperature uniformity were 5.7 % and 8.9 %. Finally, the effects of water supply temperature, water mass flow rate, pipe spacing, pipe diameter and thickness of heat distribution plate on the surface temperature distribution were quantitatively analyzed. The results showed that the water mass flow rate, pipe spacing (more than 150 mm) and the thickness of the heat distribution plate clearly influenced the surface temperature uniformity.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"328 ","pages":"Article 115200"},"PeriodicalIF":6.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.enbuild.2024.115222
Yi Cao , Hang Li , Ji Li , Yuduo Li , Guofeng Yuan , Shitong Wang , Jiangfeng Wang
Heating, ventilation, and air conditioning (HVAC) systems are major contributors to energy consumption in buildings, making performance improvement crucial for addressing energy challenges. In this paper, a novel CO2-based multi-mode integrated HVAC system is proposed. The operational modes and feasibility of the integrated system are analyzed. Experiments conducted on a self-built platform reveal variations in compressor suction and discharge pressure, temperature, ambient temperature, heating loads, and refrigerant charge under hot water mode and combined refrigeration/hot water mode. Energy, exergy, environmental, and economic analyses are performed. Results indicate that suction and discharge pressure and temperature increase with ambient temperature. However, as refrigerant charge increases, both suction and discharge pressures rise, while temperature decrease. The optimal refrigerant charge for the combined refrigeration/hot water mode is 1.80 kg, surpassing the 1.65 kg for the hot water mode. The electronic expansion valve exhibits the highest energy consumption. Compressor costs account for 51.8 % of lifecycle expenses. When ambient temperature increases from −5℃ to 35℃, pollutant emissions decrease by 20.56 %. At the same water tank outlet temperature (40℃), the CO2 system achieves a COP of 8.7 in combined refrigeration/hot water mode, 5.45 % higher than the R410A system, confirming CO2 as an effective alternative.
{"title":"Proposal and experimental study on a CO2-based multi-mode integrated HVAC system","authors":"Yi Cao , Hang Li , Ji Li , Yuduo Li , Guofeng Yuan , Shitong Wang , Jiangfeng Wang","doi":"10.1016/j.enbuild.2024.115222","DOIUrl":"10.1016/j.enbuild.2024.115222","url":null,"abstract":"<div><div>Heating, ventilation, and air conditioning (HVAC) systems are major contributors to energy consumption in buildings, making performance improvement crucial for addressing energy challenges. In this paper, a novel CO<sub>2</sub>-based multi-mode integrated HVAC system is proposed. The operational modes and feasibility of the integrated system are analyzed. Experiments conducted on a self-built platform reveal variations in compressor suction and discharge pressure, temperature, ambient temperature, heating loads, and refrigerant charge under hot water mode and combined refrigeration/hot water mode. Energy, exergy, environmental, and economic analyses are performed. Results indicate that suction and discharge pressure and temperature increase with ambient temperature. However, as refrigerant charge increases, both suction and discharge pressures rise, while temperature decrease. The optimal refrigerant charge for the combined refrigeration/hot water mode is 1.80 kg, surpassing the 1.65 kg for the hot water mode. The electronic expansion valve exhibits the highest energy consumption. Compressor costs account for 51.8 % of lifecycle expenses. When ambient temperature increases from −5℃ to 35℃, pollutant emissions decrease by 20.56 %. At the same water tank outlet temperature (40℃), the CO<sub>2</sub> system achieves a COP of 8.7 in combined refrigeration/hot water mode, 5.45 % higher than the R410A system, confirming CO<sub>2</sub> as an effective alternative.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"328 ","pages":"Article 115222"},"PeriodicalIF":6.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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