Towards an adaptive model for thermal comfort in Japanese offices

This study investigates the seasonal adaptation to temperature that occurs in Japanese offices, with a view to suggesting an adaptive model for them. Temperatures were measured in 11 office buildings and thermal comfort transverse surveys of occupants were conducted for over a year in the Tokyo and Yokohama areas of Japan. A total of 4660 samples were collected from about 1350 people. The occupants were found to be highly satisfied with the thermal environment in their offices. Even though the Japanese government recommends the indoor temperature setting of 28 degrees C for cooling and 20 degrees C for heating, the comfort globe temperature was found to be 2.6 degrees C lower in cooling mode and 4.3 degrees C higher in heating mode, in line with actual indoor temperatures. The monthly and seasonal variation in the comfort temperature was found to be significantly lower than those in dwellings. The comfort temperature is related primarily to the indoor temperature, but an adaptive relationship can be derived to estimate the indoor comfort temperature from the prevailing outdoor temperature for similar office buildings.