| Keywords |
Ventilation; Pit zips; Thermal comfort; Clothing microclimate; Bellow effect; Pumping effect |
| Abstract |
The purpose of the present study was to evaluate the wear performance of outdoor jackets featuring side ventilation designs placed at three locations?the underarm, upper-arm rear, and chest?using zippers of identical length. Thermal insulation of clothing at standing/walking with/without wind (2 m/s) was measured using a thermal manikin. Human wear trial was conducted with eight males at an air temperature of 25°C with 50%RH. A trial consisted of 10-min rest followed by 30-min exercise and 20-min recovery. Thermal insulation showed no differences among the four jacket conditions. However, insulation markedly decreased in the presence of wind (Reduction rate: 48±2% at standing and 42±1% at walking) and body movement. Human wear trials indicated no significant differences among the four jacket conditions in whole-body thermoregulatory responses, including auditory canal temperature, mean skin temperature, heart rate, total sweat loss, overall thermal sensation, and thermal comfort. In contrast, side ventilation designs influenced clothing microclimate variables and local subjective sensations (P < 0.05). The underarm-vent condition produced the lowest local microclimate temperature and humidity at the underarm region. Local thermal sensation, thermal comfort, and humidity sensation around the armpits were most favorable under the upper-arm rear vent condition. These results indicated that the strategic placement of vents improved local microclimate regulation and subjective comfort of the underarm region. Based on these findings, a curved, combined ventilation design enabling simultaneous ventilation of the underarm and upper-arm rear regions is recommended for outdoor jackets. In addition, because back-region humidity remained high even during recovery, future designs should incorporate ventilation features to effectively reduce microclimate humidity in the back area during outdoor activities. |