Field studies on thermal comfort in China over the past 30 years

Field studies are important in thermal comfort research, as they help to better understand people's needs for thermal conditions in real life. Over the past 30 years, researchers have completed numerous thermal comfort field studies in China. However, since most of the field investigations were conducted under certain conditions, such as specific building types, regions, etc., the wider reference significance from those studies was limited. Hence, this article aims to provide a comprehensive understanding of those studies. A total of 324 publications were considered. The literature was analyzed to extract and summarize key information, mainly including the measured environmental parameters and the thermal comfort perceptions from occupants. Through this analysis, the differences between climate zones, building types, and urban and rural areas were identified. It was found that indoor temperatures in the severe cold (SC) and cold (C) zones in winter were relatively higher than those in the hot summer and cold winter (HSCW) zone. In each climate zone where both district heating and non-district heating exist, the average indoor air temperature under the former condition was higher than that under the latter. Residential buildings had lower average indoor air temperatures in winter compared with office and teaching buildings, but higher temperatures in summer. In addition, the indoor air temperature in urban areas was generally higher than that in rural areas in winter. This study also presents the variations of indoor temperatures over the years. These results cover a variety of factors and may provide reference for more reasonable indoor environment control. Tables of key information from all the selected publications are provided in the appendix for other researchers to check and conduct further studies.