An analytical solution for VOCs emission from multiple sources/sinks in buildings

An analytical solution is presented to describe the emission/sorption of volatile organic compounds (VOCs) from/on multiple single-layer materials coexisting in buildings. The diffusion of VOCs within each material is described by a transient diffusion equation. All diffusion equations are coupled with each other through the equation of mass conservation in the air. The analytical solution is validated by the experimental data in literature. Compared to the one-material case, the coexistence of multiple materials may decrease the emission rate of VOCs from each material. The smaller the diffusion coefficient is, the more the emission rate decreases. Whether a material is a source or a sink in the case of multiple materials coexisting is not affected by the diffusion coefficient. For the case of multiple materials with different partition coefficients, a material with a high partition coefficient may become a sink. This may promote the emission of VOCs from other materials.