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Over the last decade, modeling of heat and mass transfer through textile materials has become a constant concern of researchers and has been directly influenced by the development of computing systems. The importance of heat and moisture transfer properties of clothing is in particular crucial in high-risk professions like firefighting or sportswear. While some analytical and numerical models have been developed about these materials, the most approaches are at the macroscopic level, where microscopic details are filtered out to reduce numerical and physical complexity. When unsteady transfer occurs the results can have significant errors. On the other hand, the simulation is a cheaper method to obtain the static or dynamic characteristics of porous materials. The goal of this paper is to model a simple textile structure and to perform a water vapour diffusion simulation using the Comsol Multiphysics(R). Comsol(R) is a software environment that allows the simulation of physical phenomena using the geometric models. The appropriate module for water vapour transfer is the Transport of Diluted Species. By applying the standard boundary conditions a comparison between the simulated and experimental value can be made. In order to have a significant results for entire system the dimension of sample was chosen so that it becomes a Representative Elementary Volume. Starting from the properties of the yarns and a geometric model of the textile structure, by simulation were acquired the global characteristics of the material such as: evaporation resistance, porosity, diffusion coefficient, diffusion flux, tortuosity and relative times for which the transfer becomes stationary. Global values were obtained by volumetric average methode, using predefined functions in Comsol(R).

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