The Investigation Of Thermal Comfort And Thermal Adaptation In Residential Buildings During The Summer Season Of Hot Summer/Cold Winter Region

This paper presents a thermal comfort field study carried out in five cities in the cold summer and cold winter region (HSCW) in China. The survey was performed in naturally ventilated and air-conditioned residential buildings during the summer season in 2006. There were 229 occupants from 111 buildings participated in this study and 229 questionnaire responses were collected. Both the field measurement and questionnaires were adopted in this study. This study is expected to provide relevant and recent data to provide a better understanding of the adequacy of existing indoor environment in providing thermal comfort in the HSCW region.Thermal acceptability assessment reveals that the indoor environment in naturally ventilated buildings couldn't meet the 80% acceptability criteria prescribed by ASHRAE Standard 55 and people tended to feel more comfortable in air-conditioned buildings because that the air-conditioned occupants voted with higher acceptability (89%) than that of the naturally ventilated occupants (58%). The neutral temperatures in naturally ventilated and air-conditioned buildings were 28.3℃and 27.7℃, respectively. The range of accepted temperature in the naturally ventilated buildings (25.0℃～31.6℃) was wider than that in air-conditioned buildings (25.1℃～30.3℃), which suggests that occupants in naturally ventilated buildings seemed to be more tolerant with high temperatures. Preferred temperature was 27.9℃and 27.3℃in naturally ventilated and air-conditioned buildings, respectively, both of which were 0.4 degrees cooler than neutral temperatures. This result suggests that people of hot climates may use words like"slightly cool"to describe their preferred thermal state. The relationship between draught sensation and indoor air velocity at different temperature ranges indicates that indoor air velocity had a significant influence over the occupants'comfort sensation and air velocities required by occupants increased with the increasing of operative temperatures. Thus, an effective way of natural ventilation which can create the preferred higher air movement is called for.Through the analysis of the survey data, we got the adaptive comfort model in the HSCW region, which could be helpful for building designers to determine the indoor set-point temperature of air-conditioning system. This model could also be used as a reference of establishing thermal comfort standards. Finally, the indoor set-point temperature of 26℃or even higher in air-conditioned buildings was confirmed to make people comfortable, which supports the regulation that in public and office buildings the set-point temperature of air-conditioning system should not be lower than 26℃in China.