Effect of Using Ceiling Fan on Human Thermal Comfort in Air-Conditioned Space

Abstract

This paper presents a study of human thermal comfort in an air-conditioned space with the additional use of a ceiling fan. A two-dimensional steady-state problem was solved by using computational fluid dynamics (CFD) simulation. The computational model includes a room with an inlet and an outlet, mounted on two opposite walls, of the air-conditioning system, and a person standing at the middle of the room right under a ceiling fan. A parametric analysis was done based on fourteen simulation cases of conditions combining different locations of the inlet diffuser as well as different vertical forced air velocities produced by the fan. Typical distributions of velocity, temperature, and relative humidity are presented. Predicted mean vote (PMV) and predicted percentage dissatisfied (PPD) are estimated to assess the thermal comfort level of the person. It is found that without the use or with little use of the ceiling fan, thermal comfort is strongly dependent on the location of the inlet diffuser; but as the vertical forced air speed produced by the fan increases, thermal comfort is increasingly dependent on this speed.