Effect of air change rate on particle dispersion from inlet opening under varying particle source strengths

In this study, effect of air change rate (air change per hour - ACH) on indoor particle dispersion and deposition in a ventilated room is investigated. A reduced-scale model is designed to conduct experiments. Numerical predictions are performed by using the commercial software ANSYS Fluent 16.0. Four different values of the air change rate (1.73, 2.88, 5.76 and 7.68) and five different values of the particle diameter (0.181, 2.188, 4.42, 8.89 and 17.8 mu m) are considered. Constant particle flow rate and proportional particle flow rate with inlet velocity cases are examined comparatively. Results show that, except from some inconsistencies for the largest particle diameter due to the accumulation and outlet opening location, the contaminant level decreases with increasing air change rate for a constant value of the particle flow rate while an opposite trend is observed for the proportional particle flow rate case.

Automated summary

The study investigates the effect of air change rate on indoor particle dispersion and deposition in a ventilated room. Experimental and numerical analysis show that the contaminant level decreases with increasing air change rate for a constant particle flow rate, while the opposite trend is observed for a proportional particle flow rate.