Diffusion studies of VOC mixtures in a building material

Volatile organic compound (VOC) adsorption by indoor materials will reduce peak concentrations, and subsequent desorption will prolong the presence of a compound indoors. Diffusion within materials plays an important role in this context. The purpose of this paper is to present two experimental set-ups to study VOC diffusion, and to show corresponding experimental results. The Field and Laboratory Emission Cell (FLEC) is in both cases an integral part of the setup. The mass flow of VOC mixtures across gypsum board is studied. Diffusion of less polar VOCs in gypsum board can be fast (diffusion coefficents of 0.001-0.003 m2/h). Diffusion coefficients of chlorinated compounds are correlated with boiling points and molecular areas. Different compounds show similar diffusion properties