Improvement of Temperatures Stratification caused by Air-conditioner by means of Ceiling Fan in Classroom

This paper discusses on the indoor thermal environment controlled by the air-conditioners and the ceiling fans under the heating condition. An experiment which measured the temperature and the indoor wind velocity was conducted in the classroom with the ceiling fans. The preset temperature was 24oC, and the airflow direction of the ceiling fans was upward. The rotational speed of the ceiling fans were changed (90-300rpm). Questionnaires to the occupants were also conducted to figure out the problem when the ceiling fans were used in the classroom. As a result, followings are shown: (1) It is confirmed that the ceiling fan is beneficial to moderate the vertical temperature difference. (2) If several ceiling fans are installed symmetrically in the classroom, there might be an increase in air velocity at the center of the classroom. (3) When the rotational speed of the ceiling fan is ordinary, noisiness does not matter.