Investigation on the thermal insulation regulating performance of a newly developed air inflatable garment

It is important to keep body thermal comfort experiencing transient thermal environments, and adjusting clothing thermal insulation is expected to be a feasible strategy. In this study, to realize the thermal insulation regulating performance, a novel air inflatable garment (AirIG) using natural air as the thermal insulator was developed, and the thickness of the air layer entrapped in AirIG was determined through computer simulation. The thermal insulation regulating performance of AirIG was investigated using ‘Newton’ thermal manikin. Thermal insulation values of the AirIG were measured under four air inflation volumes [i.e., CON (no air inflation), 1/3FULL, 2/3FULL and FULL (the maximum air inflation)]. Besides, the effects of garment pattern and air velocity (i.e., 0.15 m/s, 1.55 m/s and 3.04 m/s) on the thermal insulation regulating performance of the AirIG were also studied. Results showed that with the increasing air inflation volumes, thermal insulation in the upper of the AirIG firstly significantly increased and then remained stable (i.e., CON<1/3FULL<2/3FULL, FULL, p < 0.01). Adding sleeves remarkably increased the thermal insulation when the air inflation volume increased from CON to FULL (p = 0.056). Increasing air velocity significantly decreased the thermal insulation in the upper and local body regions of the AirIG. The thermal insulation regulating performance of the AirIG disappeared when the air velocity increased to 1.55 m/s, evidenced by the insignificant thermal insulation difference among the four air inflation volumes (p > 0.1). Therefore, the AirIG can be recommended as an effective thermal insulation regulating strategy for human body in low air velocities.