The transport of gaseous pollutants due to stack and wind effect in high-rise residential buildings

• Transport of gaseous pollutant via cracks is studied using multi-zone method.
• Airflow movements and indoor concentration levels by combined effect are analyzed.
• Effects of each parameter on concerned airflow and transport features are discussed.

Several outbreaks of severe infectious diseases occurred recently in high-rise residential (HRR) buildings have motivated a series of engineering investigations into possible airborne transmission routes. It is suspected that, driven by stack and/or wind effect, the polluted air may transport between flats through leakage cracks of doors and windows inside HRR buildings. The pure stack effect has been quantitatively studied and reported in a previous paper. This study further investigates the temporal and spatial distribution of gaseous pollutants due to combined stack and wind effect in an HRR building in Shanghai (China) with doors and windows closed. A well-established multi-zone (CONTAM) model, based on reliable boundary conditions from CFD simulations, is used to analyze the airflow movements and pollutant transport between flats via door and window leakage cracks under different scenarios. It is found that the combined stack and wind effect can cause the pollutant spread in both vertical and horizontal directions. In general, the concentrations in the top rooms are about 3–4 orders of magnitude lower than in the source room in a 33-floor building, and the concentrations on the leeward side are mainly higher than on the windward side before steady state. The effects of the outdoor/indoor temperature difference, wind field, air tightness level and source location are quite complicated due to the interaction between physical forces and the building shape. Despite the complexities, these findings have many implications that cannot be overlooked for the infectious disease control and ventilation design in HRR buildings.