Modeling of the sorption hysteresis for wood

This paper deals with an adsorption/desorption model in order to predict evolutions of boundary conditions during the mass transfer process versus time in timber elements. This model is derived from a thermodynamic balance between the free water and its saturated vapor pressure, and is generalized for the bound water phase. It allows describing a realistic adsorption and desorption phenomena characterized by a moisture content hysteresis induced by cyclic variations of the relative humidity and the temperature. The sorption isotherm explains the equilibrium between the bound water phase in wood and the vapor pressure in the environment. The model includes different latent heats for the adsorption and desorption process. An analytic explanation allows to model partial variations in terms of relative humidity domain.