Aerosol Dispersion in Ventilated Rooms: Effect of Built Space Configuration and Facemasks on Indoor Transmission

Better understanding of the dispersion of virus-laden droplets in ventilated rooms is needed to support mitigation strategies against airborne infections spread through bio-aerosols. Computational fluid dynamics tools are now widely used to study and visualize their spread. In this study, the extent of transmission and the susceptibility of virus-laden droplets on neighbouring occupants within a pair of connected, ventilated rooms are investigated (with and without the source having facemasks on). The dispersed phase model (DPM) was used to track the transmission between the two localized mannequins placed diagonally opposite each other and in separate rooms. Varying conditions of human sneezes and coughs ejected at speeds of 5, 10 and 15 m/s influenced by constant, specific, varying conditions of indoor airflow are studied to investigate the contamination of the adjoining space which contains an occupant (represented by a mannequin) at different locations. The dispersed analyses are drawn off cases of facemasks against cases without facemasks. It was established that the susceptibility of bioaerosol contamination across rooms is reduced by more than 60% when a facemask is used in comparison to cases of non-adherence to facemasks. Although within a single room (of the same dimension as one of the rooms), the transmission reduction across the room is slightly lower with the use of a facemask. As a result, this study reinforces the significance of facemasks in indoor spaces, even in separate rooms as SARS-CoV-2 or other airborne virus transmission can still occur well beyond recommended social distance spacing.