A Study on Evaporative Resistances of Two Skins Designed for Thermal Manikin Tore under Different Environmental Conditions

A cotton skin and a waterproof but permeable Gore-Tex skin were designed for the thermal
manikin “Tore” to simulate different sweating styles (the wet cotton skin inside and Gore-Tex
skin outside to simulate the sweating style of thermal manikin “Walter”, and Gore-Tex skin inside
with wet cotton skin outside to simulate the sweating style of thermal manikins “Newton”). The
evaporative resistances of two skin combinations with clothing ensembles were compared at different
environmental conditions. In addition, the total evaporative resistance of clothing ensemble was
calculated by both the heat loss method (option 1) and the mass loss method (option 2) according to
ASTM F 2370. We found that the effect of different sweating mechanisms on the clothing evaporative
resistance should be considered. The results showed that the total evaporative resistances calculated
by option 2 were more accurate than values in option 1 under the isothermal condition. It was also
found that differences of the total evaporative resistance between two skin combinations with clothing
ensembles decreased with the increasing clothing ensemble layer. In a non-isothermal condition, the
total evaporative resistance calculated by option 1 was more accurate than the value obtained in option
2, which was due to the lower ambient temperature and condensations between each adjacent layer.