An Analysis of Simultaneous Heat and Water Vapour Transfer through Waterproof Breathable Fabrics

Abstract

Perforated metal cylinders were used to investigate simultaneous heat and water vapour transfer through breathable fabrics. The analysis of the condensa tion problem made use of the heat loss and water vapour loss lines obtained from ex periments. An attempt was made to solve the problem of condensation within a clothing system by adjusting a saturation line and water vapour concentration line. For the best results to avoid condensation it was suggested that the innermost fabric near the human body should possess excellent breathability and low thermal resis tance, the outer fabric interfacing with the environment should possess the lowest breathability and highest thermal resistance and the properties of the wadding in be tween should fall between these extremes.