Thermal responses of young males of three thermal preference groups in summer indoor environments

Abstract

This study aimed to explore the differences in thermal responses of three thermal preference groups of young male university students during summer. A questionnaire was administered to divide participants into three groups: cold thermal preference (Gcp), neutral thermal preference (Gnp), and warm thermal preference (Gwp). Human trials were performed in a climate chamber where the operative temperature was set at 26, 29, and 32 °C to represent three summer indoor environments. The core temperature, skin temperature, conductive heat flux, heart rate, thermal sensation vote (TSV), and thermal comfort vote (TCV) were recorded throughout the tests. The results indicated that the three groups differed (p < 0.05) in core temperature, heart rate, TSV, and TCV in the 29 and 32 °C environments but did not differ in the 26 °C environment. No significant difference was observed in the mean skin temperature between the groups, whereas the local skin temperature differed between the groups at some body segments. The Gwp subjects were more sensitive to indoor temperature variations in skin temperature than the Gcp subjects; however, they were less sensitive to thermal perceptions. Furthermore, differences were observed in the thermal responses of the three thermal preference groups during summer and winter. The findings of this study provide insights into the evaluation of the thermal responses of individuals, indoor environment control, and energy savings in buildings.