Difference in thermal sensation and behavioural pattern of occupants between passive and active cooling strategies.

We made a series of subjective experiments to grasp individual behaviours and thermal sensation of the occupants in as actual environmental conditions as possible by observation using video cameras. The use of video cameras allows us to have the time-series of scenes of the occupants participating in the experiment; it also allows us to avoid disturbing their natural behaviours and sensations. In this subjective experiment, we focused on investigating how the use of cross ventilation, the use of small fans, the use of air conditioners and the choice of path approaching to the building influence individual behaviours and thermal sensation. It was found that most of the subjects in a room with cross ventilation were very sensitive to the fluctuation of the air current in the given thermal environment and also very active in having coolness. It does not necessarily require lower room temperature in a case that the subjects approach the room by walking in milder outdoor environment. We also made an interview on the subjects' lifestyles including the use of air conditioners and cross ventilation in their daily life. It was found that the subjects who usually use air conditioners in their daily life imagine their comfortable temperature in summer lower than the actual environmental temperature (SET*) to which they are exposed and feel comfortable.