AbstractElastocaloric cooling has no environmental effects during operation, and achieving a compact structure especially the driver is significant for its commercialization. In this article, a compact, standalone crankshaft driven single long NiTi tube compressive elastocaloric cooler is developed. A crankshaft driver was designed and fabricated to drive a compressive elastocaloric regenerator utilizing a single long polycrystalline superelastic NiTi shape memory alloy tube (outer diameter 5 mm, wall thickness 1 mm, and initial length 305 mm). A novel design of ceramic heat insulation plate was applied to the cooler to reduce the conduction heat loss from the NiTi tube to the stainless-steel loading heads. The cooling performance of the cooler was characterized using synchronized thermocouples and infrared thermography, and the specific cooling(heating) power, temperature span, and coefficient of performance of up to 65(125) W·kg−1, 9.1 K, and 5.0, respectively were measured. The progressions of the temperature span, specific cooling(heating) power, and coefficient of performance with the operation cycle and temperature lift were analyzed. An energy analysis revealed that the heat transfer fluid carried out only 14% of the latent heat generated by the NiTi tube, which demonstrated a potential to enhance the cooling performance by the improvement in the regenerator structure. AcknowledgementsWe thank Mr. Yuchen Zhang, Mr. Jiachen Lei, Mr. Junxian Ye, and Mr. William Chi Chung Wong in the Hong Kong University of Science and Technology for the beneficial discussions and construction of the crankshaft driver in the single long NiTi tube compressive elastocaloric cooler.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the National Natural Science Foundation of China (Grant No. 52206224), the Natural Science Research Start-up Foundation of Recruiting Talents of Hebei University of Science and Technology, the Chinese National Training Program of Innovation and Entrepreneurship for Undergraduates (Grant No. 202310082008), and the IER Foundation 2020 (Grant No. IERF202003).Notes on contributorsSiyuan ChengSiyuan Cheng, PhD, is an Assistant Professor. Zhengyu Li, BS, is a PhD Candidate. Weng Zak Lee, is an Undergraduate Student. Shuoyang Liu, is an Undergraduate Student. Yang Fu, is an Undergraduate Student. Yatao Zhao, is an Undergraduate Student. Mengyi Zhang, is an Undergraduate Student.
{"title":"Development of a crankshaft driven single long NiTi tube compressive elastocaloric cooler","authors":"Siyuan Cheng, Zhengyu Li, Weng Zak Lee, Shuoyang Liu, Yang Fu, Yatao Zhao, Mengyi Zhang","doi":"10.1080/23744731.2023.2242756","DOIUrl":"https://doi.org/10.1080/23744731.2023.2242756","url":null,"abstract":"AbstractElastocaloric cooling has no environmental effects during operation, and achieving a compact structure especially the driver is significant for its commercialization. In this article, a compact, standalone crankshaft driven single long NiTi tube compressive elastocaloric cooler is developed. A crankshaft driver was designed and fabricated to drive a compressive elastocaloric regenerator utilizing a single long polycrystalline superelastic NiTi shape memory alloy tube (outer diameter 5 mm, wall thickness 1 mm, and initial length 305 mm). A novel design of ceramic heat insulation plate was applied to the cooler to reduce the conduction heat loss from the NiTi tube to the stainless-steel loading heads. The cooling performance of the cooler was characterized using synchronized thermocouples and infrared thermography, and the specific cooling(heating) power, temperature span, and coefficient of performance of up to 65(125) W·kg−1, 9.1 K, and 5.0, respectively were measured. The progressions of the temperature span, specific cooling(heating) power, and coefficient of performance with the operation cycle and temperature lift were analyzed. An energy analysis revealed that the heat transfer fluid carried out only 14% of the latent heat generated by the NiTi tube, which demonstrated a potential to enhance the cooling performance by the improvement in the regenerator structure. AcknowledgementsWe thank Mr. Yuchen Zhang, Mr. Jiachen Lei, Mr. Junxian Ye, and Mr. William Chi Chung Wong in the Hong Kong University of Science and Technology for the beneficial discussions and construction of the crankshaft driver in the single long NiTi tube compressive elastocaloric cooler.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the National Natural Science Foundation of China (Grant No. 52206224), the Natural Science Research Start-up Foundation of Recruiting Talents of Hebei University of Science and Technology, the Chinese National Training Program of Innovation and Entrepreneurship for Undergraduates (Grant No. 202310082008), and the IER Foundation 2020 (Grant No. IERF202003).Notes on contributorsSiyuan ChengSiyuan Cheng, PhD, is an Assistant Professor. Zhengyu Li, BS, is a PhD Candidate. Weng Zak Lee, is an Undergraduate Student. Shuoyang Liu, is an Undergraduate Student. Yang Fu, is an Undergraduate Student. Yatao Zhao, is an Undergraduate Student. Mengyi Zhang, is an Undergraduate Student.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"167 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134983649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-09DOI: 10.1080/23744731.2023.2247948
M. Van Hove, J. Borrajo Bastero, M. Delghust, J. Laverge
Combined building indoor climate and energy simulation models only recently gained vast popularity and their application has been moving from the research community to a broader audience. Yet, in-situ empirical validation of this new generation of complex multi-purpose dynamic simulation models has lagged behind. Using a dynamic multizone building indoor climate and energy simulation model in Modelica with the IDEAS library and buoyancy driven airflow components (validated with CONTAM), this research presents model validation results and lessons learned from an in-situ empirical validation study of common indoor climate parameters (i.e., indoor air temperature ( ), relative humidity (RH) and CO2 concentration (CO2)) for an inhabited and mechanically ventilated case study dwelling in The Netherlands. The simulation results show that the latest generation of building indoor climate and energy models in Modelica have great ability to accurately predict common indoor climate parameters in multizone inhabited dwellings (provided that user behavior info is available). Evaluation metrics for the three studied parameters show excellent calibration criteria (i.e., MAE between 0.60–0.78 °C ( ), 3.5–4.6% (RH) and 88–181 ppm (CO2)) and the accompanying graphs corroborate the findings. In the event that no motion sensor data is available, statistically generated occupancy profiles prove good representative alternatives on the condition that basic info is available about the number of inhabitants and the inhabitants’ lifestyle. In-situ monitoring for empirical model validation proves to be a real challenge full of (un)foreseen obstacles.
{"title":"In-situ empirical validation of common indoor climate parameters in an inhabited multizone dwelling","authors":"M. Van Hove, J. Borrajo Bastero, M. Delghust, J. Laverge","doi":"10.1080/23744731.2023.2247948","DOIUrl":"https://doi.org/10.1080/23744731.2023.2247948","url":null,"abstract":"Combined building indoor climate and energy simulation models only recently gained vast popularity and their application has been moving from the research community to a broader audience. Yet, in-situ empirical validation of this new generation of complex multi-purpose dynamic simulation models has lagged behind. Using a dynamic multizone building indoor climate and energy simulation model in Modelica with the IDEAS library and buoyancy driven airflow components (validated with CONTAM), this research presents model validation results and lessons learned from an in-situ empirical validation study of common indoor climate parameters (i.e., indoor air temperature ( ), relative humidity (RH) and CO2 concentration (CO2)) for an inhabited and mechanically ventilated case study dwelling in The Netherlands. The simulation results show that the latest generation of building indoor climate and energy models in Modelica have great ability to accurately predict common indoor climate parameters in multizone inhabited dwellings (provided that user behavior info is available). Evaluation metrics for the three studied parameters show excellent calibration criteria (i.e., MAE between 0.60–0.78 °C ( ), 3.5–4.6% (RH) and 88–181 ppm (CO2)) and the accompanying graphs corroborate the findings. In the event that no motion sensor data is available, statistically generated occupancy profiles prove good representative alternatives on the condition that basic info is available about the number of inhabitants and the inhabitants’ lifestyle. In-situ monitoring for empirical model validation proves to be a real challenge full of (un)foreseen obstacles.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"730 - 747"},"PeriodicalIF":1.9,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47691034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-09DOI: 10.1080/23744731.2023.2254102
Chandra Sekhar, William Bahnfleth
{"title":"IAQ 2020: Indoor environmental quality performance approaches transitioning from IAQ to IEQ, part 2 May 4–6, 2022 | Athens, Greece","authors":"Chandra Sekhar, William Bahnfleth","doi":"10.1080/23744731.2023.2254102","DOIUrl":"https://doi.org/10.1080/23744731.2023.2254102","url":null,"abstract":"","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135747018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-09DOI: 10.1080/23744731.2023.2247947
Youngbo Won, Donghyun Rim, R. Mistrick, W. Bahnfleth
Ultraviolet germicidal irradiation (UVGI) systems inactivate microorganisms indoors. Upper-room UVGI systems use wall- or ceiling-mounted fixtures to create an air disinfection zone above the occupied zone. The performance of upper-room UVGI systems varies with indoor airflow patterns induced by mechanical ventilation and thermal plumes from indoor heat sources. Little information is available on the effects of ventilation strategies on upper-room UVGI system performance for the control of viral aerosols in occupied spaces. This study simulated the effects of ventilation system characteristics in an office space on the ability of an upper-room UVGI system to inactivate viral aerosols with UV-C susceptibility representative of coronaviruses. UVGI reduced viral aerosol concentration by two orders of magnitude relative to the concentration without UVGI. Air change rates and air distribution strategy (mixing vs. displacement) had notable effects on the effectiveness of the UVGI system. For mixing ventilation, as the recirculation airflow rate increased from 0 to 5.3 h−1 for a room volume of 108 m3 with a fixed outdoor air change rate of 0.7 h−1, UVGI inactivation increased by 96.7%. Mixing ventilation with 100% outdoor air of 0.7 h−1 yielded airborne virus inactivation that was double that of displacement ventilation, due to enhanced air mixing.
{"title":"CFD modeling of room airflow effects on inactivation of aerosol SARS-CoV-2 by an upper-room ultraviolet germicidal irradiation (UVGI) system","authors":"Youngbo Won, Donghyun Rim, R. Mistrick, W. Bahnfleth","doi":"10.1080/23744731.2023.2247947","DOIUrl":"https://doi.org/10.1080/23744731.2023.2247947","url":null,"abstract":"Ultraviolet germicidal irradiation (UVGI) systems inactivate microorganisms indoors. Upper-room UVGI systems use wall- or ceiling-mounted fixtures to create an air disinfection zone above the occupied zone. The performance of upper-room UVGI systems varies with indoor airflow patterns induced by mechanical ventilation and thermal plumes from indoor heat sources. Little information is available on the effects of ventilation strategies on upper-room UVGI system performance for the control of viral aerosols in occupied spaces. This study simulated the effects of ventilation system characteristics in an office space on the ability of an upper-room UVGI system to inactivate viral aerosols with UV-C susceptibility representative of coronaviruses. UVGI reduced viral aerosol concentration by two orders of magnitude relative to the concentration without UVGI. Air change rates and air distribution strategy (mixing vs. displacement) had notable effects on the effectiveness of the UVGI system. For mixing ventilation, as the recirculation airflow rate increased from 0 to 5.3 h−1 for a room volume of 108 m3 with a fixed outdoor air change rate of 0.7 h−1, UVGI inactivation increased by 96.7%. Mixing ventilation with 100% outdoor air of 0.7 h−1 yielded airborne virus inactivation that was double that of displacement ventilation, due to enhanced air mixing.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"719 - 729"},"PeriodicalIF":1.9,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42018499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-07DOI: 10.1080/23744731.2023.2244337
Yilin Jiang, Junke Wang, Li Song
Many utility companies in the United States have introduced time-of-use (TOU) rates for homeowners with the goal of regulating electricity consumption during peak hours. The electrical appliances in homes include various thermostatically controlled devices, such as air conditioners (AC) for thermal comfort, and nonthermostatically controlled devices such as clothes washers. As a result, homeowners face the complicated challenge of economically operating multiple electrical appliances in their homes while maintaining comfort and convenience. This is usually due to the lack of an explicit understanding of the correlation between cost saving and the users’ comfort. To understand the correlation, this article is designed to construct a framework by integrating three major components: a multi-objective optimization method accommodating multiple competing goals with different weights, a learning-based system modeling approach describing the dynamics and thermal coupling effects of appliances, and a novel comfort index method differentiating preferred and acceptable thermal comfort. Our proposed framework can allow the indoor air temperature to fall into the "preferred" range with a marginal cost increase. The simulation result shows that an additional 8 h for the preferred thermal comfort can be achieved with a cost increase of only 1.77%.
{"title":"Quantitative analysis of cost savings and occupants’ preferences in grid-interactive smart home operation","authors":"Yilin Jiang, Junke Wang, Li Song","doi":"10.1080/23744731.2023.2244337","DOIUrl":"https://doi.org/10.1080/23744731.2023.2244337","url":null,"abstract":"Many utility companies in the United States have introduced time-of-use (TOU) rates for homeowners with the goal of regulating electricity consumption during peak hours. The electrical appliances in homes include various thermostatically controlled devices, such as air conditioners (AC) for thermal comfort, and nonthermostatically controlled devices such as clothes washers. As a result, homeowners face the complicated challenge of economically operating multiple electrical appliances in their homes while maintaining comfort and convenience. This is usually due to the lack of an explicit understanding of the correlation between cost saving and the users’ comfort. To understand the correlation, this article is designed to construct a framework by integrating three major components: a multi-objective optimization method accommodating multiple competing goals with different weights, a learning-based system modeling approach describing the dynamics and thermal coupling effects of appliances, and a novel comfort index method differentiating preferred and acceptable thermal comfort. Our proposed framework can allow the indoor air temperature to fall into the \"preferred\" range with a marginal cost increase. The simulation result shows that an additional 8 h for the preferred thermal comfort can be achieved with a cost increase of only 1.77%.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43057398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-07-25DOI: 10.1080/23744731.2023.2239081
Jianqiao Mao, Dr Ryan Grammenos, K. Karagiannis
Energy efficiency and thermal comfort levels are key attributes to be considered in the design and implementation of a Heating, Ventilation and Air Conditioning (HVAC) system. With the increased availability of Internet of Things (IoT) devices, it is now possible to continuously monitor multiple variables that influence a user’s thermal comfort and the system’s energy efficiency, thus acting preemptively to optimize these factors. To this end, this paper reports on a case study with a two-fold aim; first, to analyze the performance of a conventional HVAC system through data analytics; secondly, to explore the use of interpretable machine learning techniques for HVAC predictive control. A new Interpretable Machine Learning (IML) algorithm called Permutation Feature-based Frequency Response Analysis (PF-FRA) is also proposed. Results demonstrate that the proposed model can generate accurate forecasts of Room Temperature (RT) levels by taking into account historical RT information, as well as additional environmental and time-series features. Our proposed model achieves 0.4017 °C and 0.9417 °C of Mean Absolute Error (MAE) for 1-h and 8-h ahead RT prediction, respectively. Tools such as surrogate models and Shapley graphs are employed to interpret the model’s global and local behaviors with the aim of increasing trust in the model.
{"title":"Data analysis and interpretable machine learning for HVAC predictive control: A case-study based implementation","authors":"Jianqiao Mao, Dr Ryan Grammenos, K. Karagiannis","doi":"10.1080/23744731.2023.2239081","DOIUrl":"https://doi.org/10.1080/23744731.2023.2239081","url":null,"abstract":"Energy efficiency and thermal comfort levels are key attributes to be considered in the design and implementation of a Heating, Ventilation and Air Conditioning (HVAC) system. With the increased availability of Internet of Things (IoT) devices, it is now possible to continuously monitor multiple variables that influence a user’s thermal comfort and the system’s energy efficiency, thus acting preemptively to optimize these factors. To this end, this paper reports on a case study with a two-fold aim; first, to analyze the performance of a conventional HVAC system through data analytics; secondly, to explore the use of interpretable machine learning techniques for HVAC predictive control. A new Interpretable Machine Learning (IML) algorithm called Permutation Feature-based Frequency Response Analysis (PF-FRA) is also proposed. Results demonstrate that the proposed model can generate accurate forecasts of Room Temperature (RT) levels by taking into account historical RT information, as well as additional environmental and time-series features. Our proposed model achieves 0.4017 °C and 0.9417 °C of Mean Absolute Error (MAE) for 1-h and 8-h ahead RT prediction, respectively. Tools such as surrogate models and Shapley graphs are employed to interpret the model’s global and local behaviors with the aim of increasing trust in the model.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"698 - 718"},"PeriodicalIF":1.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47950823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-07-21DOI: 10.1080/23744731.2023.2239080
I. Pittana, F. Morandi, F. Cappelletti, A. Gasparella, Athanasios Tzempelikos
Students in classrooms are exposed to environmental stimuli in the thermal, visual, acoustic and air quality domains, which affect their overall comfort and performance. Therefore, in recent studies, questionnaires are used to collect information about subjective perceptions and investigate links with physical parameters. Most field studies in educational buildings either focus on a single comfort domain, or consider multiple domains but provide inconsistent questions among the 4 domains (i.e., IAQ, thermal, visual and acoustic). Very few studies have investigated cross-domain effects in a consistent manner, considering satisfaction, comfort and perception aspects. To address this research gap, a survey with consistent questions among the 4 comfort domains was designed and used to collect more than 900 subjective responses from students. The analysis of subjective data together with objective measurements allows: (i) correlating the environmental physical parameters and students’ perception in each of the comfort domains; (ii) understanding the students’ preferred environmental conditions; and (iii) understanding cross-domain effects, i.e., the effects between the average conditions and the mean vote expressed for another domain. The results show that air temperature, illuminance and sound pressure level are correlated with the sensation in the respective domains, in contrast to CO2 concentration. Regarding cross-effects, the study confirms interference of CO2 concentration and illuminance on thermal sensation as well as the effect of sound pressure level on visual sensation.
{"title":"Within- and cross-domain effects of environmental factors on students’ perception in educational buildings","authors":"I. Pittana, F. Morandi, F. Cappelletti, A. Gasparella, Athanasios Tzempelikos","doi":"10.1080/23744731.2023.2239080","DOIUrl":"https://doi.org/10.1080/23744731.2023.2239080","url":null,"abstract":"Students in classrooms are exposed to environmental stimuli in the thermal, visual, acoustic and air quality domains, which affect their overall comfort and performance. Therefore, in recent studies, questionnaires are used to collect information about subjective perceptions and investigate links with physical parameters. Most field studies in educational buildings either focus on a single comfort domain, or consider multiple domains but provide inconsistent questions among the 4 domains (i.e., IAQ, thermal, visual and acoustic). Very few studies have investigated cross-domain effects in a consistent manner, considering satisfaction, comfort and perception aspects. To address this research gap, a survey with consistent questions among the 4 comfort domains was designed and used to collect more than 900 subjective responses from students. The analysis of subjective data together with objective measurements allows: (i) correlating the environmental physical parameters and students’ perception in each of the comfort domains; (ii) understanding the students’ preferred environmental conditions; and (iii) understanding cross-domain effects, i.e., the effects between the average conditions and the mean vote expressed for another domain. The results show that air temperature, illuminance and sound pressure level are correlated with the sensation in the respective domains, in contrast to CO2 concentration. Regarding cross-effects, the study confirms interference of CO2 concentration and illuminance on thermal sensation as well as the effect of sound pressure level on visual sensation.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"678 - 697"},"PeriodicalIF":1.9,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46832438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-07-14DOI: 10.1080/23744731.2023.2235971
Yapan Liu, Bing Dong, Tianzhen Hong, B. Olesen, Tom Lawrence, Zheng O’Neill
In developed countries, people spend nearly 90% of their time in buildings or during transportation. Recent research studies demonstrated that occupant behaviors have a significant impact on building performance in relation to the indoor environment and energy use. This paper presents the ASHRAE Global Occupant Behavior Database which aims to advance the knowledge and understanding of realistic occupancy patterns and human-building interactions with building systems. This database includes 34 field-measured occupant behavior datasets for both commercial and residential buildings, contributed by researchers from 15 countries and 39 institutions covering 10 different climate zones. It includes occupancy patterns, occupant behaviors, indoor and outdoor environment measurements. The database is open source, a public website was developed for the users to interactively explore, query, and download datasets. This paper focuses on a detailed data analysis to investigate patterns of nine occupant behavior types, examining impacted factors such as building type, country, and climate zone. EnergyPlus simulations have been implemented based on the occupancy profiles derived from this database, and results showed overall building electricity consumption can be reduced up to around 27% in Summer and around 10% in Winter.
{"title":"ASHRAE URP-1883: Development and Analysis of the ASHRAE Global Occupant Behavior Database","authors":"Yapan Liu, Bing Dong, Tianzhen Hong, B. Olesen, Tom Lawrence, Zheng O’Neill","doi":"10.1080/23744731.2023.2235971","DOIUrl":"https://doi.org/10.1080/23744731.2023.2235971","url":null,"abstract":"In developed countries, people spend nearly 90% of their time in buildings or during transportation. Recent research studies demonstrated that occupant behaviors have a significant impact on building performance in relation to the indoor environment and energy use. This paper presents the ASHRAE Global Occupant Behavior Database which aims to advance the knowledge and understanding of realistic occupancy patterns and human-building interactions with building systems. This database includes 34 field-measured occupant behavior datasets for both commercial and residential buildings, contributed by researchers from 15 countries and 39 institutions covering 10 different climate zones. It includes occupancy patterns, occupant behaviors, indoor and outdoor environment measurements. The database is open source, a public website was developed for the users to interactively explore, query, and download datasets. This paper focuses on a detailed data analysis to investigate patterns of nine occupant behavior types, examining impacted factors such as building type, country, and climate zone. EnergyPlus simulations have been implemented based on the occupancy profiles derived from this database, and results showed overall building electricity consumption can be reduced up to around 27% in Summer and around 10% in Winter.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47948209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-07-12DOI: 10.1080/23744731.2023.2235970
Jian Sun, T. Kuruganti, Brian Fricke, Yanfei Li, S. Xuan, Wenhua Li
With the increasing concerns over climate change and carbon emissions, fault detection and diagnostics (FDD) of low–global warming potential (GWP) refrigerant supermarket refrigeration systems has gained great attention from academic and industrial sectors. Various FDD approaches have been developed to detect, identify, and diagnose faults to save energy, improve food quality, and protect the environment. To mitigate the difficulty of collecting high-quality steady-state operational data in field operations faced by most model-based FDD methods, this study developed dynamic models of a low–GWP refrigerant (CO2) supermarket refrigeration system. The model accuracy was validated using manufacturer data and experimental data. Simulations were conducted to predict the system dynamic response under two common operational faults—evaporator air path blockage fault and the display case door open fault—to identify fault patterns and define key dynamic behavior indexes for supporting FDD algorithm development.
{"title":"Dynamic model-based feature extraction for fault detection and diagnosis of a supermarket refrigeration system1","authors":"Jian Sun, T. Kuruganti, Brian Fricke, Yanfei Li, S. Xuan, Wenhua Li","doi":"10.1080/23744731.2023.2235970","DOIUrl":"https://doi.org/10.1080/23744731.2023.2235970","url":null,"abstract":"With the increasing concerns over climate change and carbon emissions, fault detection and diagnostics (FDD) of low–global warming potential (GWP) refrigerant supermarket refrigeration systems has gained great attention from academic and industrial sectors. Various FDD approaches have been developed to detect, identify, and diagnose faults to save energy, improve food quality, and protect the environment. To mitigate the difficulty of collecting high-quality steady-state operational data in field operations faced by most model-based FDD methods, this study developed dynamic models of a low–GWP refrigerant (CO2) supermarket refrigeration system. The model accuracy was validated using manufacturer data and experimental data. Simulations were conducted to predict the system dynamic response under two common operational faults—evaporator air path blockage fault and the display case door open fault—to identify fault patterns and define key dynamic behavior indexes for supporting FDD algorithm development.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46730451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-07-11DOI: 10.1080/23744731.2023.2234251
Xiaozhou Wu, Hao Gao, Diqi Yu, Jiying Liu, Jie Gao, Zhen Tian, Xiangli Li
A hybrid system with a ceiling cooling (CC) system and a mechanical ventilation system has been extensively applied in modern office buildings with large sensible cooling loads. Both the chilled ceiling and supply air may greatly influence indoor air distribution in the office room. Therefore in this paper, indoor air distribution performances in a ceiling cooling room with underfloor air distribution (UFAD) or mixing ventilation (MV) were sensitively analyzed by numerical simulation. Indoor air distribution performances, which were evaluated by the heat removal effectiveness, contamination removal effectiveness and air diffusion performance index, were quantitatively analyzed by using the orthogonal experiment method. The results showed that when the supply air temperature was 18 °C-24 °C for CC + UFAD and 16 °C-21 °C for CC + MV, the heat removal effectiveness changed by 0.01 with 1 °C increment of supply air temperature or ceiling surface temperature, and the contamination removal effectiveness increased by 0.001-0.002 with 1 W/m2 increment of external sensible cooling load. Moreover, the air diffusion performance index increased by 0.6%-1.1% with 1 °C increment of supply air temperature, and it decreased by 0.02% with 1 W/m2 increment of internal sensible cooling load. Finally, formulas of heat removal effectiveness, contamination removal effectiveness and air diffusion performance index for CC + UFAD and CC + MV were obtained by fitting, and they may provide guidance for the optimal design and control of a hybrid system with a ceiling cooling system and a mechanical ventilation system.
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