Modelling of emission of volatile organic compounds from building materials—estimation of gas-phase mass transfer coefficient

Abstract

A mathematical model is developed to predict Volatile Organic Compound (VOC) emission rates from homogeneous materials. The model considers both mass diffusion and mass convection processes in the boundary layer between the material surface and the air flow. Establishing the relationship between the surface air flow and emission rate; the model, therefore can predict the material emission rate under different environmental conditions. The other feature of the model is that all the parameters have clear physical meaning and can be either found in literature or calculated using known theories and/or equations. The prediction of the mathematical model was validated at three different levels; with experimental results from the CBS specially designed test chamber, with experimental results from the EPA which were carried out in an ASTM chamber, and finally with the predictions made by other models. The results indicate that there is, in general, good agreement between the model predictions and the experimental results. The main advantage of this model is that the model does not require any experimental data as input.