Thermal comfort and occupant adaptive behaviour in Japanese university buildings with free running and cooling mode offices during summer

Thermal comfort is one of the most important factors for satisfying occupants within indoor environments, especially in regions that experience warm summer seasons, and analyses of thermal comfort and occupant behaviour are critical for the effective implementation of energy saving programs. This paper presents the results of studies on the thermal comfort and adaptive behaviour of occupants in university buildings with free running (FR) and cooling (CL) mode offices in Fukuoka, Japan. Both thermal measurements and thermal comfort surveys were conducted during the summer season. The mean thermal sensation vote (TSV) in FR and CL modes was 0.7 and −0.1, respectively. These data show that occupants in FR mode offices felt slightly warmer than those in CL mode offices, where occupants typically reported feeling neutral. The mean comfort temperature for both cases, as estimated by using the Griffiths method, was 26.6 °C. For personal clothing, we found that the use of clothing insulation was inversely proportional to the outdoor temperature. The adaptive behaviours of occupants were found to be more active in FR mode offices compared to those in CL mode offices, which were more passive. This indicates that amenable thermal conditions were present in the air conditioning (A/C)-controlled indoor environments where occupants expressed no wish to make changes.