Influence of local airflow on the pollutant emission from indoor building surfaces.

A study was done to obtain a general understanding of the mechanisms involved in the emissions from building materials in ventilated rooms. The investigation was based on fundamental fluid dynamics and mass transfer theory. Also proposed a generally applicable method for the prediction of surface emissions. No particulate emissions were analysed, and the work focused on the emission of vapours and gases. Numerical calculations by CFD and full-scale laboratory experiments were used. The findings indicated that the emissions are a strong function of air change rate, local air velocity and local turbulence, as the mass transfer coefficient increases proportionately to these parameters. The study also found that the mass transfer coefficient increases with the velocity when the emission is governed by evaporation from the surface. For diffusion-controlled emissions, the mass transfer coefficient is unaffected by the velocity.