Performance of Selected Clothing Systems under Subzero Conditions: Determination of Performance by a Human-Clothing-Environment Simulator

It is necessary to measure the performance of outdoor/protective clothing materials in terms of comfort properties under dynamic enduse conditions. A vertical type human-clothing-environment simulator was used to evaluate the thermal comfort performance of layered textile materials under dynamic conditions. Fabric layers of PET knit/fleece and PET knit/micro-porous membrane (MPM), which simulate clothing systems, were compared at a transient state from 25 to -10°C. PVC film was used to compare the effects of permeability. Relative humidity and vapor pressure data confirmed condensation on the fabric layers of the clothing systems during the transient period of temperature decrease. At the subzero condition, fabrics with low air permeability kept the water molecules on their inner surface, which deteriorates the permeability of the membranes. The vapor pressure of the air layer next to the environment was maintained at a relatively high level, which will reduce the driving force for moisture transport from sweating skin to the environment.