Testing and evaluating the thermal comfort of clothing ensembles

By using the manikin tests and human trials, many researchers have assessed thermal comfort performance of different types of regular and specialized clothing (Barker, 2008 Bhattacharjee and Kothari, 2009 Famworth, 1983 Hes et al., 1996 Huck and 

2 Factors affecting thermal comfort performance of clothing 

Fiber is the basic element to manufacture a fabric. Fiber properties have a significant effect on thermal insulation characteristics of textiles. Important fiber properties are fineness or hnear density, length, cross-section, and crimp (Matsudaira et al., 1993 Murakami et al., 1978 Varshney et al., 2011). 

Fineness or linear density. Fiber fineness affects thermal insulation and is expressed in terms of denier (weight of 9(X)0m of fiber in grams) (Li, 2001 Varshney et al., 2011). For a given weight of fiber, a smaller ratio of fiber surface to volume is available in the case of coarse fibers compared with fine fibers. As the fiber surface traps air, a given weight of coarse fiber wiU trap less air than a similar amount of fine fiber. Consequently, coarse fibers wiU generally provide less thermal insulation than fine fibers (Wu et al., 2008). 

Cross-section. The cross-section of a fiber can be observed using a microscope. It has been found that the cross-sectional shape of a fiber can have a significant effect on its thermal insulation characteristics (Varshney et al., 2011). A fiber s cross-section with more trapped air may provide higher thermal insulation than a perfectly cylindrical fiber. For example, a hollow fiber traps more air inside its structure than a solid circular fiber. This is the reason why hoUow-fiber based fabrics can provide higher thermal insulation than solid circular-fiber based fabrics. In the same fashion, a noncircular fiber, say with a trilobal or scalloped oval surface, can trap more air than a circular fiber, because of its shape. Relatively large amounts of air trapped by noncircular fibers ultimately enhance thermal insulation characteristics (Matsudaira et al., 1993 Murakami etal, 1978). 

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Testing and evaluating the thermal comfort of clothing ensembles... 

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