Investigation of thermal adaptability based on facial temperature and subjective evaluation indexes of during the use of HVAC in a summer office

Thermal adaptation is closely related to building energy, as the process of thermal adaptation within a building can influence energy consumption and efficiency. This study was aimed at analyzing thermal adaptation using subjective evaluation indexes of occupants and facial temperature data in a centralized control system building. Conducted during the summer in an office with a centralized HVAC system, this study utilized Thermal Sensation Vote (TSV), Thermal Comfort Vote (TCV), and Temperature Sensation Index (TSI) as subjective evaluation indices. The results indicated that occupants required, on average, 30 min to achieve thermal adaptation. A facial temperature of 34°C before thermal adaptation indicated discomfort, whereas the same facial temperature after thermal adaptation indicated comfort. These findings highlight the importance of considering thermal adaptation in HVAC design, as efficient thermal management can significantly impact energy consumption. Incorporating thermal adaptation strategies into HVAC systems could improve energy efficiency while enhancing occupant comfort. Therefore, when predicting thermal comfort in future buildings, it is essential to consider both the thermal adaptation of occupants and subjective evaluation indices alongside physiological signals. • Occupants took about 30 min to achieve thermal acclimatization. • A facial temperature of 34°C indicated discomfort before adaptation and comfort afterward. • Thermal adaptation, along with subjective and physiological data, is crucial for predicting future building comfort.