INVESTIGATING THE INFLUENCE OF THE WALL MATERIALS AND THICKNESS ON THE REVERSIBLE SINK EFFECT

摘要

The paper deals with a numerical study of the interactions between gaseous air pollutants and building materials. The model used is based on the assembly of elemental mass transfer models including boundary layer diffusion, diffusion in porous materials and sorption at the gas and solid interfaces. Adequate diffusion and sorption data was input in the model to dynamically calculate the room air acetone concentrations, the acetone concentrations in the pores of the materials, and the contaminant flow-rate at the room air and wall interface, for various configurations of contaminant sources and building walls. The temporal profiles observed clearly show the "buffer" effect of the wall and the strong analogy with conductive thermal transfer in buildings. A parametric study is then carried out to investigate the influence of the material thickness on the resulting room air concentrations. It shows that increasing the material thickness over a critical value doesn't significantly change the indoor air concentration profile.