Study on behavioral adaptation for the adaptive thermal comfort and energy saving in Japanese office buildings

Office workers use a variety of adaptive opportunities to regulate their indoor thermal environment. The behavioural adaptations such as window opening, clothing adjustments, and use of heating/cooling are important factors for adaptive thermal comfort. It is well-known that they are the most important contributors in the adaptive thermal comfort model. Thus, if we understand the behavioural adaptation properly, we can explain the mechanism of the adaptive model. The indoor thermal environment is often adjusted using the air conditioning in Japanese office buildings to improve thermal comfort and productivity. Thus, it is necessary to conduct research on the behavioural adaptation in the offices because the occupant behaviour is different from behaviour in dwellings. In order to record the seasonal differences in behavioural adaptation and to develop an adaptive algorithm for Japanese offices, we measured temperatures in seven office buildings and conducted the thermal comfort and occupant behaviour survey for over a year. We collected 1,228 samples. The proportion of ‘open window’ is significantly high in the free running and air conditioned modes. The behavioural adaptation is related to the outdoor air temperature. The clothing adjustments, heating and cooling use can be predicted by regression equations. These findings can be applied to building thermal simulation to predict the behavioural adaptation and energy use in office buildings.