The Effect of Flow Rate of a Short Sleeve Air Ventilation Garment on Torso Thermal Comfort in a Moderate Environment

In recent years, air ventilation garments (AVG) have been reported effective to improve thermal comfort. In this study, an AVG incorporated with small fans was investigated on torso thermal comfort in moderate environment (Ta=25 °C, RH=50 %). Eight female subjects walked on the treadmill at a speed of 4 km·h−1 for 30 min and then rested for another 30 min. During the whole test protocol, the AVG was worn in three conditions of flow rates to examine which flow rate was the best choice to keep thermal comfort: fans off with no air ventilation (a controlled condition, CON), low flow rate (12 l/s, LOW) and high flow rate (20 l/s, HIGH). Results showed that HIGH made significantly lowered local skin temperature of the abdomen, scapula and the lower back (p<0.05). The mean torso skin temperature in CON, LOW and HIGH in the last 5 min in the exercising stage was 32.3, 30.2 and 29.2 °C, respectively and it was 32.1, 29.5 and 28.2 °C, respectively in the resting stage. HIGH significantly mitigated thermal sensation in the 40 and 50th min (p<0.05), whereas it produced cool and unpleasant thermal sensation in the resting stage. In the whole test scenario, LOW produced the best torso thermal comfort. The low flow rate of ventilation (12 l/s) should be recommend and used in such a moderate environment to maintain torso thermal comfort.