Sorption kinetics model application on the measurement ofwater vapor permeability in building materials

Abstract

This work proposes a simple experimental technique that provides a method, based on sorption kinetics, for the measurement of water vapor permeability of building materials. It is a novel method that has the added interest of easily providing data in a few hours using a dynamic process of moisture absorption based on a pseudo-second-order kinetic model. Experimental measurements of water vapor permeability covering four different types of building materials were carried out for a range of the relevant parameters, such as temperature and relative humidity. The experimental results obtained are in good agreement with the experimental values of the water vapor permeability measured by our team and other researchers using the classic standard cup method; and the results showed that the moisture buffer performance, from a different step of relative humidity, can be predicted with the knowledge of previous values and the kinetics parameters specific to a material using the equations proposed in this work.