Characterizing the performance of a single-layer fabric system through a heat and mass transfer model - Part I: Heat and mass transfer model

A mathematical model was developed to study the coupled heat and moisture transfer through a fabric system that consists of a single layer of fabric and an air gap. Properties of air and moisture are sensitive to temperature and, hence, were assumed to be functions of local temperature. Therefore, the model is applicable to a broad range of boundary conditions. A numerical scheme was proposed to solve the distributions of temperature and water vapor concentration throughout the layers, from which the thermal and evaporative resistances of the fabric system were evaluated. Experiments were conducted for two particular fabrics using a sweating guarded hotplate, and the data show good agreement with the model predictions, suggesting that the heat and mass transfer model is capable of accurately predicting thermal and evaporative resistances for the single-layer fabric system.