The effect of local ventilation on airborne viral transmission in indoor spaces

We incorporate local ventilation effects into a spatially dependent generalisation of the Wells--Riley model of airborne viral transmission. Aerosol production and removal through ventilation (global and local), biological deactivation, and gravitational settling as well as transport around a recirculating air-conditioning flow and turbulent mixing are modelled using an advection--diffusion--reaction equation. The local ventilation effects are compared with the equivalent global ventilation and we find that the streamlines of the airflow provide insight into when the global ventilation model is a good approximation. When the agreement between ventilation models is poor, we find that the global ventilation model generally overestimates the infection risk.