Effects of surface radiation on gaseous contaminants emission and dispersion in indoor environment - A numerical study

This study presents a computational fluid dynamics (CFD) study on the effects of surface radiation on the emission and dispersion of gaseous contaminants in indoor spaces. Mathematical models are firstly validated against experimental data reported in the literature. It demonstrates that the Shear Stress Transport (SST) k-omega model performs best among other turbulence models when modelling convection-radiation hybrid heat transfer. The study also reveals that surface radiation accounts for 37%-71% of the heat dissipation from the heat sources in a typical office room, which remarkably alters the indoor airflow pattern through cooling and heating the solid surfaces. Beyond that, the emission rate of volatile organic compounds (VOCs) from solid surfaces is also changed due to its dependence on the temperature. Consequently, the VOCs exhibit different dispersion characteristics and distribution patterns in the air, which ultimately results in different evaluations of the indoor air quality (IAQ). This study demonstrates that even in high-momentum indoor spaces such as those equipped with mixing ventilation systems, surface radiation still plays an important role in shaping the overall indoor environment quality (IEQ). (C) 2018 Elsevier Ltd. All rights reserved.