The indoor thermal history of residents in the hot summer and cold winter climate zone in China have undergone a significant change in recent years,which also changes their seasonal thermal adaptations and this has fo...The indoor thermal history of residents in the hot summer and cold winter climate zone in China have undergone a significant change in recent years,which also changes their seasonal thermal adaptations and this has formed feed-back effects to the increasing usage of air conditioning units in this area.To study the seasonal variations of thermal adaptation,the thermal comfort experiments were conducted on two groups of participants.Each groups included 20 participants who had indoor history mainly with natural ventilation(NV group)and air-conditioning(AC group),respectively.The results demonstrated that the thermal sensation vote(TSV)in warm environments did not differ between AC and NV subjects in summer.However,the TSV of AC subjects were much lower than that of NV subjects in the same standard effective temperature and skin temperature in a cold environment in winter.Overall,the participants who spent most of their time in AC space in winter showed a low level of thermal adaptation with a narrower acceptable skin temperature range of 32.6-33.5℃.Thus,this study presents the basic information regarding the seasonal effects on human thermal adaptation due to different long-term indoor thermal histories.展开更多
The hot environment and the metabolic heat of commuting in summer caused individual overheating and intense thermal discomfort.Local cooling presents huge potential for optimizing thermal comfort.This study investigat...The hot environment and the metabolic heat of commuting in summer caused individual overheating and intense thermal discomfort.Local cooling presents huge potential for optimizing thermal comfort.This study investigates the performance of a back cooling device,based on the semiconductor Peltier effect,in improving thermal comfort after summer commuting.We studied one case without cooling,and three cases with surface temperatures of the cooling device of 29,27,and 25℃using a simulated summer commute at a moderate activity level.The results showed that thermal sensation,perceived sweating rate,and skin temperature decreased markedly in the cooling cases compared to the non-cooling case,with the changes being most notable in the lower back,in contact with the cooling device.The decrease in overall thermal sensation and mean skin temperature was approximately 0.52 score and 0.31℃on average,respectively,with a 1.71 score increase in overall thermal comfort.We contend that the surface temperature of local contact cooling devices should not be lower than 22℃to minimize local overcooling.Back cooling devices present a huge potential for building energy-savings at ambient air temperature exceeding 30℃.Moreover,the functional paradigms for individual comfort predict improved comfort performance in future applications.This study contributes to the understanding on the well-being and physiological recovery of individuals after a summer commuting.展开更多
Storing thermal energy in mass concrete floors would have a major impact on the stability of the temperature in buildings.The concept of a thermal battery refers to storing the supplied radiant heat and releasing this...Storing thermal energy in mass concrete floors would have a major impact on the stability of the temperature in buildings.The concept of a thermal battery refers to storing the supplied radiant heat and releasing this heat the next day through radiation and convection.In this study,an approach is introduced to examine the idea of thermal battery in thick concrete flooring(1.22 m)using the earth as a heat source.Controlled experiments were built and conducted on an instrumented 3000 m 2 industrial facility.The heating radiant floor combining with ground source system was operated during off-peak hours and the air conditioning system was disabled for 24 h during the test period.The heat pumps were operated in single stage using less power compared to when operated on demand.Indoor air temperature showed that 100(37.78℃)supply temperature at the ground source heat pump would be enough to maintain a stable warm temperature during cold days.Two weather conditions in the winter were selected to do the tests.The second test had a colder ambient temperature to verify the procedure.The indoor air temperature showed that the night heating system performs well for both cases because it maintained a constant temperature for the entire operational day even in the daytime when every heating unit was off.This approach of applying the heating at nighttime with lower electricity rates would lead to significant operational cost savings in the building.展开更多
Individual thermal comfort models based on physiological parameters could improve the efficiency of the personal thermal comfort control system.However,the effect of thermal history has not been fully addressed in the...Individual thermal comfort models based on physiological parameters could improve the efficiency of the personal thermal comfort control system.However,the effect of thermal history has not been fully addressed in these models.In this study,climate chamber experiments were conducted in winter using 32 subjects who have different indoor and outdoor thermal histories.Two kinds of thermal conditions were investigated:the temperature dropping(24-16℃)and severe cold(12℃)conditions.A simplified method using historical air temperature to quantify the thermal history was proposed and used to predict thermal comfort and thermal demand from physical or physiological parameters.Results show the accuracies of individual thermal sensation prediction was low to about 30%by using the PMV index in cold environments of this study.Base on the sensitivity and reliability of physiological responses,five local skin temperatures(at hand,calf,head,arm and thigh)and the heart rate are optimal input parameters for the individual thermal comfort model.With the proposed historical air temperature as an additional input,the general accuracies using classification tree model C5.0 were increased up by 15.5%for thermal comfort prediction and up by 29.8%for thermal demand prediction.Thus,when predicting thermal demands in winter,the factor of thermal history should be considered.展开更多
Diisononyl phthalate (DINP), considered to be an environmentally friendly plasticizer, is now widely used. However, the toxic effects of DINP need to be examined, particularly the effects of long-term dermal DINP ex...Diisononyl phthalate (DINP), considered to be an environmentally friendly plasticizer, is now widely used. However, the toxic effects of DINP need to be examined, particularly the effects of long-term dermal DINP exposure. Research into the mechanisms underlying these effects is urgently needed. In this study we examined the exacerbation effect of long-term dermal exposure to DINP in flnorescein isothiocyanate (FITC)-induced contact hypersensitivity (CHS) in mice, and sought the potential molecular mechanisms. Forty-nine male Balb/c mice were subjected to a 40-day dermal exposure to saline or one of three concentrations of DINP and then three rounds of sensitization with vehicle or 0.5% FITC. The results of a histopathological examination and measurement of ear swelling as well as immunological and inflammatory biomarkers (total-immunoglobulin (Ig)E and Th cytokines) supported the notion that high doses of DINP may aggravate atopic dermatitis. We also showed that melatonin, an antioxidant, could decrease the levels of oxidative stress and alleviate FITC-induced CHS suggesting that oxidative stress may be one of the molecular mechanisms to explain the exacerbation effect induced by DINP.展开更多
This paper analyzes the potential of natural resources to improve the indoor thermal environment in Chongqing through the statistical analysis of natural resources including solar energy,wind,water,and earth,etc.The b...This paper analyzes the potential of natural resources to improve the indoor thermal environment in Chongqing through the statistical analysis of natural resources including solar energy,wind,water,and earth,etc.The building form,systems,and principle of usage of natural resources are briefly analyzed through the building site decision,building form design,and computer simula-tion,which will be the real reference for the design of building energy efficiency.展开更多
基金supported by the High-end Foreign Experts Recruitment Plan of China(Grant No.G2021165006L),and the 111 Project(Grant No.B13041).
文摘The indoor thermal history of residents in the hot summer and cold winter climate zone in China have undergone a significant change in recent years,which also changes their seasonal thermal adaptations and this has formed feed-back effects to the increasing usage of air conditioning units in this area.To study the seasonal variations of thermal adaptation,the thermal comfort experiments were conducted on two groups of participants.Each groups included 20 participants who had indoor history mainly with natural ventilation(NV group)and air-conditioning(AC group),respectively.The results demonstrated that the thermal sensation vote(TSV)in warm environments did not differ between AC and NV subjects in summer.However,the TSV of AC subjects were much lower than that of NV subjects in the same standard effective temperature and skin temperature in a cold environment in winter.Overall,the participants who spent most of their time in AC space in winter showed a low level of thermal adaptation with a narrower acceptable skin temperature range of 32.6-33.5℃.Thus,this study presents the basic information regarding the seasonal effects on human thermal adaptation due to different long-term indoor thermal histories.
基金supported by the 1ll Project(Grant No.B13041)support from the Chinese Scholarship Council(Grant No.202406050003).
文摘The hot environment and the metabolic heat of commuting in summer caused individual overheating and intense thermal discomfort.Local cooling presents huge potential for optimizing thermal comfort.This study investigates the performance of a back cooling device,based on the semiconductor Peltier effect,in improving thermal comfort after summer commuting.We studied one case without cooling,and three cases with surface temperatures of the cooling device of 29,27,and 25℃using a simulated summer commute at a moderate activity level.The results showed that thermal sensation,perceived sweating rate,and skin temperature decreased markedly in the cooling cases compared to the non-cooling case,with the changes being most notable in the lower back,in contact with the cooling device.The decrease in overall thermal sensation and mean skin temperature was approximately 0.52 score and 0.31℃on average,respectively,with a 1.71 score increase in overall thermal comfort.We contend that the surface temperature of local contact cooling devices should not be lower than 22℃to minimize local overcooling.Back cooling devices present a huge potential for building energy-savings at ambient air temperature exceeding 30℃.Moreover,the functional paradigms for individual comfort predict improved comfort performance in future applications.This study contributes to the understanding on the well-being and physiological recovery of individuals after a summer commuting.
文摘Storing thermal energy in mass concrete floors would have a major impact on the stability of the temperature in buildings.The concept of a thermal battery refers to storing the supplied radiant heat and releasing this heat the next day through radiation and convection.In this study,an approach is introduced to examine the idea of thermal battery in thick concrete flooring(1.22 m)using the earth as a heat source.Controlled experiments were built and conducted on an instrumented 3000 m 2 industrial facility.The heating radiant floor combining with ground source system was operated during off-peak hours and the air conditioning system was disabled for 24 h during the test period.The heat pumps were operated in single stage using less power compared to when operated on demand.Indoor air temperature showed that 100(37.78℃)supply temperature at the ground source heat pump would be enough to maintain a stable warm temperature during cold days.Two weather conditions in the winter were selected to do the tests.The second test had a colder ambient temperature to verify the procedure.The indoor air temperature showed that the night heating system performs well for both cases because it maintained a constant temperature for the entire operational day even in the daytime when every heating unit was off.This approach of applying the heating at nighttime with lower electricity rates would lead to significant operational cost savings in the building.
基金This research was financially supported by the National Key Research and Development Program of China(No.2019YFE0100300-05)the Fundamental Research Funds for the Central Universities(No.2020CDCGJ027)+2 种基金the 111 Project(No.B13041)Academy of Finland(No.329306)The author,Yuxin Wu,would like to thank the Chinese Scholarship Council(No.201806050244)for their sponsorship of a research visiting study aboard at Aalto University in Finland.
文摘Individual thermal comfort models based on physiological parameters could improve the efficiency of the personal thermal comfort control system.However,the effect of thermal history has not been fully addressed in these models.In this study,climate chamber experiments were conducted in winter using 32 subjects who have different indoor and outdoor thermal histories.Two kinds of thermal conditions were investigated:the temperature dropping(24-16℃)and severe cold(12℃)conditions.A simplified method using historical air temperature to quantify the thermal history was proposed and used to predict thermal comfort and thermal demand from physical or physiological parameters.Results show the accuracies of individual thermal sensation prediction was low to about 30%by using the PMV index in cold environments of this study.Base on the sensitivity and reliability of physiological responses,five local skin temperatures(at hand,calf,head,arm and thigh)and the heart rate are optimal input parameters for the individual thermal comfort model.With the proposed historical air temperature as an additional input,the general accuracies using classification tree model C5.0 were increased up by 15.5%for thermal comfort prediction and up by 29.8%for thermal demand prediction.Thus,when predicting thermal demands in winter,the factor of thermal history should be considered.
文摘Diisononyl phthalate (DINP), considered to be an environmentally friendly plasticizer, is now widely used. However, the toxic effects of DINP need to be examined, particularly the effects of long-term dermal DINP exposure. Research into the mechanisms underlying these effects is urgently needed. In this study we examined the exacerbation effect of long-term dermal exposure to DINP in flnorescein isothiocyanate (FITC)-induced contact hypersensitivity (CHS) in mice, and sought the potential molecular mechanisms. Forty-nine male Balb/c mice were subjected to a 40-day dermal exposure to saline or one of three concentrations of DINP and then three rounds of sensitization with vehicle or 0.5% FITC. The results of a histopathological examination and measurement of ear swelling as well as immunological and inflammatory biomarkers (total-immunoglobulin (Ig)E and Th cytokines) supported the notion that high doses of DINP may aggravate atopic dermatitis. We also showed that melatonin, an antioxidant, could decrease the levels of oxidative stress and alleviate FITC-induced CHS suggesting that oxidative stress may be one of the molecular mechanisms to explain the exacerbation effect induced by DINP.
文摘This paper analyzes the potential of natural resources to improve the indoor thermal environment in Chongqing through the statistical analysis of natural resources including solar energy,wind,water,and earth,etc.The building form,systems,and principle of usage of natural resources are briefly analyzed through the building site decision,building form design,and computer simula-tion,which will be the real reference for the design of building energy efficiency.