Numerical evaluation of influence of door opening on interzonal air exchange

Ventilation plans for rooms with contaminated air must address pollutants because they affect the air quality of adjacent areas. A ventilation plan typically maintains a negative room pressure to remedy this problem. However, the transport of indoor air pollutants between rooms is affected by the movements of humans and doors. The purpose of this study was to evaluate the influence of door opening on the interzonal air exchange volume. We measured the interzonal air exchange volume by dispersing sulfur hexafluoride (SF₆) as a tracer gas, swinging or sliding a door between an air-contaminated room and a corridor in an office building, and measuring the direction and velocity of the airflow. The results were compared to those of a computational fluid dynamics (CFD) simulation. We modeled the influence of swinging and sliding of a door at various speeds and air temperature differences between rooms on the interzonal air exchange volume. The measured absolute interzonal air exchange volume was very similar to the value obtained from CFD simulation (0.428 m³), and the measured and simulated values of flow rate variation over time were also quite similar. The interzonal air exchange volume through the doorway was decreased to 0.052 m³ with a sliding door, compared to 0.317 m³ for a swing door, for isothermal conditions. However, the interzonal air exchange volume through the doorway were not significantly different for a swing door versus sliding door when a temperature difference between areas was involved.