ASHRAE updates airborne transmission guidance

The ASHRAE Epidemic Task Force has updated its statement on the airborne transmission of SARS-CoV-2 in buildings.

According to the Atlanta, GA-based association, “Airborne transmission of SARS-CoV-2 is significant and should be controlled. Changes to building operations, including the operation of heating, ventilating, and air-conditioning systems, can reduce airborne exposures.”ASHRAE


In April 2020 ASHRAE reported that “airborne transmission was ‘sufficiently likely’ that airborne precautions should be taken,” based on World Health Organization and the Centers for Diseases Control statements that transmission of SARS-CoV2 was by droplet and fomite modes rather than airborne. Both organizations have since recognized the risk of indoor airborne transmission.


“This may seem like a small step, but we feel it is important to leave no doubt about our position, given the muted support for ventilation and filtration as important tools in the effort to stop the pandemic, from some organizations that should be leading more strongly,” says ASHRAE Epidemic Task Force chair William P. Bahnfleth.


The ASHRAE Epidemic Task Force was formed in March 2020 to develop and distribute guidance for the control of airborne transmission of SARS-CoV-2. For more information on the new statement visit