Personalized ceiling fans: Effects of air motion, air direction and personal control on thermal comfort

Abstract

Research related to personal comfort systems is growing due to their potential to increase an individual’s satisfaction with indoor environmental conditions and energy efficiency. At moderately high indoor temperatures, the use of ceiling fans can be a low-energy cooling strategy to enhance comfort in a working environment. This paper studies the performance of a personal ceiling fan and its influence on occupants’ satisfaction with the indoor environment, focusing on the effects of personal control, previous experience with fans, variations on participants’ activity level and air coming from different directions. In a laboratory study, 41 participants from two age groups were exposed to six different ceiling fan configurations either in sitting or standing positions, with and without control over the ceiling fan speed, and under two thermal conditions (balanced order of in total 24 conditions). Results showed that participants’ thermal comfort at indoor temperatures of 28 °C and 31 °C was fulfilled when they used the personal ceiling fan, independent of the direction of the supplied air coming from above. The possibility to control the fan speed showed a significant influence on the thermal perception of participants at a slightly higher activity level compared to fully sedentary. The influence of previous experiences with fans had a positive effect on the rating of the analyzed ceiling fan and thermal comfort. The positive acceptance of personal ceiling fans encourages its use in retrofitted office buildings to increase thermal comfort and motivate energy savings.