The government has published Covid-19 official guidance for the UK healthcare sector. Guidance for infection prevention and control in healthcare settings states that the main means of transmission are via droplet and contact, but it says precautions against airborne transmission should be taken when performing aerosol-generating procedures, such as surgery using high-speed devices.
It also says Covid-19 can survive on inanimate objects and remain viable for up to five days at temperatures of 22-25°C and relative humidity of 40-50%.
To clear aerosols, there should be a minimum of six air changes per hour (ACH) in general wards and 12 ACH in negative- pressure isolation rooms. One air change is calculated to remove 63% of airborne contaminants. See