The cooling performance of forced air ventilation garments in a warm environment: the effect of clothing eyelet designs

Abstract

Heat stress is a common danger for people who work or exercise in hot environments. A Newton manikin was used to evaluate the cooling performance of five forced air ventilation garments (AVGs) with newly designed eyelet sizes and positions, including no eyelets (control), small eyelets at the mid-back, large eyelets at the mid-back, small eyelets at both the mid-back and upper front, large eyelets at both the mid-back and upper front (abbr. CON, B1, B2, FB1, FB2, respectively). The AVGs in fans turned on (Fan-On) and turned off (Fan-Off) were measured in a constant temperature mode (CT, 34 °C, 69% RH, and 0.20 m/s) and a thermoregulatory control mode (TMC, 30 °C, 69% RH, and 0.2 m/s) to simulate human exercising and resting. Air volume between the skin and clothing was also measured using a 3 D laser scanner. FB1 resulted the highest heat loss both in the chest zone (109.2 W/m2) and the stomach zone (77.1 W/m2) in the Fan-On conditions, and it also resulted the lowest torso skin temperature, mean skin temperature and core temperature. The air volume of the eyelet designs in Fan-On was all reduced when compared to that of CON, with FB2 having the greatest reduction by 14.5%. The eyelet designs significantly reduced clothing bulkiness (p < 0.05), but had no significant effect on the torso heat loss (p > 0.05).