Students Responses to Thermal Environments in University Classrooms in Zunyi, China

Abstract

Indoor thermal environment has significant influence on occupants’ working efficiency, study performance and well-being, particularly in space with high population density but no HVAC system. Therefore, in order to understand the indoor thermal environmental conditions and subjects’ interactions with ambient physical environment, a field study was carried out during winter time in naturally ventilated classrooms in Zunyi, China. The range of indoor air temperature variation during investigation period, 11.57°C to 19.80°C, was not within the thermal comfort zone recommended by ASHRAE 55 Standard. Nearly 80% of occupants regarded indoor thermal condition as ‘slight cool’ and ‘cool’, and wanted indoor environment to be warmer as a consequence. The thermal neutral temperature, acceptable range and thermal sensitivity under AMV model were 20.27°C, 16.60-23.95°C and 4.33°C / unit, respectively. People’s clothing adjustment followed the tendency that the mean values of clothing insulation decreased gradually with indoor air temperature increasing. The discrepancies of subjects’ thermal sensations, thermal neutral temperatures, thermal acceptable temperature zone and thermal sensitivity reflected the adaptations of occupants in response to ambient thermal stimuli. Due to the more tolerance of cold environment revealed in this study, the energy used for space heating would be reduced to some extent. The findings obtained from this investigation also provide guidelines on building refurbishment, maintenance and new building design.