Study on the kinetic characteristics of indoor air pollutants removal by ventilation

Ventilation is an efficient and convenient method to remove indoor air pollutants, such as particulate matter and VOCs. The computational fluid dynamics (CFD) method is an economical and efficient method to study the removal efficiency of indoor air pollutants by ventilation. However, CFD method is usually restricted by the extensive computational time. In this study, the kinetic characteristic of removing indoor air pollutants by ventilation was investigated to reduce the CFD computational time. The impact of ventilation rate and ventilation model on the removal efficiency of indoor air pollutants was studied. The results show that the removal of particulate matter and VOCs is consistent with the Langmuir-Hinshelwood (L-H) kinetic model when there are no barriers. The fit coefficients (R-2) are larger than 0.984 and 0.978 under different ventilation rates and ventilation models, respectively. The fit coefficients of VOCs removal are larger than those of particulate matter. The removal of VOCs in a benchmark full-scale indoor model was successfully predicted by the L-H kinetic model with a mean prediction error of 0.8%. Meanwhile, 99% CFD computational times were reduced. The removal of particulate matter cannot be predicted accurately by the L-H kinetic model when the barriers present (prediction error reached 18.0%). Therefore, the L-H kinetic model is a high-efficient tool to design the ventilation rate and ventilation model when the main air pollutants are airflow-determined (gaseous pollutants or no barriers condition).