Hong Kong Med J 2012;18(Suppl 2):S39-41
Inter-flat airflow and airborne disease transmission in high-rise residential buildings
J Niu, CW Tung, N Gao
Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong
1. A virus-spread mechanism is related to inter-flat or inter-zonal airflow through open windows caused by buoyancy effects.
2. Both on-site measurements and numerical simulations quantify the amount of the exhaust air that exits the upper part of the window of a floor and re-enters the lower part of the open window of the immediately upper floor.
3. Ventilation air could contain up to 7% (in terms of mass fraction) of the exhaust air from the lower floor.
4. In high-rise buildings, windows flush with the facade are a major route for the vertical spread of pathogen-containing aerosols, especially those <1 µm in diameter.