The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recently launched a web page that provides guidance to its members on how to help address coronavirus disease 2019 (COVID-19) concerns in the operation and maintenance of heating, ventilating and air-conditioning systems.

“The recent escalation in the spread of coronavirus disease 2019 is alarming on a global scale,” said ASHRAE president Darryl K. Boyce, P.Eng. “While ASHRAE supports expanded research to fully understand how coronavirus is transmitted, we know that healthy buildings are a part of the solution. ASHRAE’s COVID-19 Preparedness Resources are available as guidance to building owners, operators and engineers on how to best protect occupants from exposure to the virus, in particular in relation to airborne particles that might be circulated by HVAC systems.”

Available on the page is ASHRAE’s recently approved position document on Airborne Infectious Diseases. The society’s recommends that all facilities follow, as a minimum, the latest practical standards and guidelines.

Some of the publications referenced in the position document and on the resources webpage include:

• ANSI/ASHRAE Standard 62.1-2019, Ventilation for Acceptable Indoor Air Quality.
• ANSI/ASHRAE Standard 62.2-2019, Ventilation for Acceptable Indoor Air Quality in Residential Buildings.
• ANSI/ASHRAE/ASHE Standard 170-2017, Ventilation of Health Care Facilities.
• ANSI/ASHRAE Standard 52.2-2017, Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size.
• ANSI/ASHRAE Standard 55-2017, Thermal Environmental Conditions for Human Occupancy.
• ANSI/ASHRAE Standard 161-2018, Air Quality within Commercial Aircraft.
• ASHRAE Guideline 28-2016, Air Quality within Commercial Aircraft.

The position document also recommends that new and existing healthcare intake and waiting areas, crowded shelters, and similar facilities should go beyond the minimum requirements of these documents, using techniques covered in ASHRAE’s Indoor Air Quality Guide to be even better prepared to control airborne infectious disease (including a future pandemic caused by a new infectious agent).

Because small particles remain airborne for some period of time, the design and operation of HVAC systems that move air can affect disease transmission in several ways, such as by the following:

• Supplying clean air to susceptible occupants
• Containing contaminated air and/or exhausting it to the outdoors
• Diluting the air in a space with cleaner air from outdoors and/or by filtering the air
• Cleaning the air within the room

Owners, operators and engineers are encouraged to collaborate with infection prevention specialists knowledgeable about transmission of infection in the community and the workplace and about strategies for prevention and risk mitigation.