Turbulence correction for thermal comfort calculation

Thermal comfort in ventilated spaces depends mainly on air temperature, air speed and turbulence intensity. Mean air speed is commonly measured with o mnidirectional hot sphere sensors, whereas directionally sensitive measurem ent instruments and CFD-simulations normally give the mean velocity vector. The magnitude of the mean velocity vector in turbulent room air flows can be much lower than the mean air speed due to different time averaging proce sses. This paper studies the difference both experimentally and theoretical ly as a function of turbulence intensity. A correction method was developed for calculating estimates for omnidirectional mean air speed and turbulenc e intensity from directional air velocity data. The method can be applied t o the calculation of draught risk and thermal comfort from CFD-simulation r esults. (C) 2000 Elsevier Science Ltd. All rights reserved.