The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has published two statements to provide guidance to its members about the transmission of the SARS-CoV-2, the novel coronavirus, through buildings’ heating, ventilation and air-conditioning systems.

“In light of the current global pandemic, it’s critically important that ASHRAE responds with guidance on mitigating the transmission of the virus, as well as ventilation and filtration recommendations,” said ASHRAE president Darryl K. Boyce. “ASHRAE has a significant role to play in ensuring safe and healthy building environments and these statements offer the expert strategies needed at this time.”

Through its Epidemic Task Force, the society has developed two statements in response to what it calls “widening false statements surrounding HVAC systems.” Indeed, the society says it opposes any advice to not run residential or commercial HVAC systems. It also advises that that keeping air conditioners on during the pandemic can help control the spread of the virus.

Its official statement on the airborne transmission of the novel coronavirus is as follows:

Transmission of SARS-CoV-2 through the air is sufficiently likely that airborne exposure to the virus should be controlled. Changes to building operations, including the operation of heating, ventilating, and air-conditioning systems, can reduce airborne exposures.

A second statement on the operation of HVAC systems to reduce transmission says:

Ventilation and filtration provided by heating, ventilating, and air-conditioning systems can reduce the airborne concentration of SARS-CoV-2 and thus the risk of transmission through the air. Unconditioned spaces can cause thermal stress to people that may be directly life threatening and that may also lower resistance to infection. In general, disabling of heating, ventilating, and air-conditioning systems is not a recommended measure to reduce the transmission of the virus.

HVAC filters, it adds, can be part of the strategy to reduce virus transmission and remove other air contaminants that may have health effects.

“ASHRAE, working with its industry partners, is uniquely qualified to provide guidance on the design, operation, and maintenance of heating, ventilation, and air-conditioning systems to the COVID-19 pandemic as well as to prepare for future epidemics,” said Epidemic Task Force chair Bill Bahnfleth.

The ASHRAE Epidemic Task Force comprises nine experts with deep experience in system design, construction, operations and research. The task force is supported by leading public-health and medicine experts. Its mandate is to address the relationship between the spread of disease and HVAC in buildings during the current pandemic and future epidemics.