Quantifying the Cooling Sensation of Air Movement

A number of methods have been used to quantify the cooling effects of air movement on the human body. For simplicity these methods limit the number of variables influencing the effect. A new method using the difference in Standard Effective Temperature (SET*) values between a condition with 29.5 fpm (0.15 m/s) and the proposed elevated air speed allows all the relevant variables (i.e. air temperature, mean radiant temperature, air speed, humidity, metabolic rate, and clothing insulation) to be taken into account. Cooling effect of air movement is normally based on uniform velocity airflow. Research indicates that gusting airflow with a frequency around 0.5 Hz increases the cooling effect. Uniform air speeds with an equivalent cooling effect to 0.5 Hz gusting airflows are provided for low air speeds.