Assessment of Clothing Effects in Thermal Comfort Standards

Book excerpt: There are four international standards covering the measurement of thermal resistance of clothing, i.e., ISO 15831, ASTM F 1291, ASTM F 1720, and EN 342. They employ the same measurement technique, but they differ in manikin size, test conditions, formula for calculating the insulation, and the parameters for reporting the test results. ASTM F 2370 is the only standard that addresses the measurement of evaporative resistance of clothing. It specifies the configuration of sweating thermal manikin, test protocol and test conditions, and does not call for a specific technique to simulate body sweating. ISO 9920 provides formulas for estimating thermal insulation and evaporative resistance of clothing. The international standards for the assessment of thermal comfort or thermal strain of a clothed body include ISO 7730, ISO/TR 11079 and ISO 7933, for evaluating moderate thermal, cold and hot environments, respectively. Their applications of thermal properties of clothing, principles, and limitations vary. Several suggestions are finally projected with regard to the future revision of these standards.