A New CFD Model for VOC Emission Based on the General Adsorption Isotherm

This paper presents a new CFD model for the transportation of volatile organic compound (VOC) from building materials to the room air in the case with high VOC concentration in the air when Langmuir model or other nonlinear adsorption isotherms are used. In this model, the concentration equation solves the equivalent air-phase concentration and uses the equivalent air-phase diffusion coefficient to calculate the mass flux. A new parameter, specific mass, arising from adsorption isotherm is presented to account for the sorption and desorption effect. The present model and two previous models are applied to the steady and unsteady problems. Results show that the present model correctly simulates the emission of VOC from building materials. And the present model is easy to use with commercial CFD software.