  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.
