The HSE have sent out a ebulletin regarding COVID19 and air conditioning and what the risks are for work places that currently have air conditioning in place.
The ebulletin reads as follows:
The risk of air conditioning spreading coronavirus is extremely low.
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.
It seems from the advice provided that the risk is relatively low, however caution should still be taken when using air conditioning in the workplace during the COVID19 pandemic.