The risk of air conditioning spreading coronavirus is extremely low.
HSE have advised the following:
If you use a centralised ventilation system that removes and circulates air to different rooms, it is recommended that you turn off recirculation and use a fresh air supply.
You do not need to adjust other types of air conditioning systems.
If you’re unsure, speak to your heating ventilation and air conditioning (HVAC) engineers or advisers.
Good ventilation is encouraged to help reduce the risk of spreading coronavirus.
HSE, 22 May 2020