Small fan assisted air conditioner for thermal comfort and energy saving in Thailand

From the fact that Thai people have a tolerance to high air temperature and are accustomed to high air movement from electric fans in non-air conditioned space, this paper proposes the use of small fan assisted air conditioners for human thermal comfort and energy saving in Thailand. In the study, a total 15 students were tested in a 2.5 × 3.5 × 2.5 m3 test room equipped with a 12,000 Btu/h split type air conditioner. During the tests, the room air temperature was varied from 25, 26, 27 and 28 °C every 1 h. A small fan with 15 cm diameter was placed in front of each subject. In each hour, the small fan was varied to supply a small area with velocity from 0.2, 0.5, 1, 1.5 and 2 m/s. In each condition, the subjects were asked to vote for their thermal sensation. The results showed that the temperature set point could be increased up to 28 °C when a small fan was used to supply local air velocity from 0.5 to 2 m/s according to individual preference. This would reduce the electricity consumption of the air conditioning unit. According to the proposed method, this can save energy for office buildings in the commercial sector as high as 1959.51 GWh/year.