ASHRAE has developed resources for building-industry professionals to address how the heating, ventilating and air conditioning industries can help combat the virus. The resources can be found on the ASHRAE webpage at ashrae.org/COVID19.
“The recent escalation in the spread of coronavirus 2019 is alarming on a global scale,” said Darryl K. Boyce, ASHRAE president, 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.”
The ASHRAE position on airborne infectious diseases states that “all types should follow, as a minimum, the largest practical standards and guidelines.” This includes:
- ANSI/ASHRAE Standard 62.1 – ventilation for acceptable IAQ, which outlines minimum ventilation rates and other measures intended to provide IAQ that is acceptable to human occupants and that minimize adverse health effects.
- ANSI/ASHRAE Standard 62.2 – ventilation for acceptable IAQ in residential buildings, which defines the roles of and minimum requirements for mechanical and natural ventilation systems and the building envelope intended to provide acceptable IAQ in low-rise residential buildings.
- ANSI/ASHRAE/ASHE Standard 170 – ventilation of health care facilities, which addresses hospital spaces, outpatient spaces, and nursing home spaces.
- ANSI/ASHRAE Standard 52.2 – method of testing general ventilation air-cleaning devices for removal efficiency by particle size, which establishes a method of laboratory testing to measure the performance of general ventilation air-cleaning devices in removing particles of specific diameters.
- ANSI/ASHRAE Standard 55 – thermal environmental conditions for human occupancy, which specifies conditions for acceptable thermal environments and is intended for use in design, operation, and commissioning of buildings and other occupied spaces.
- ANSI/ASHRAE Standard 185.2 – method of testing ultraviolet lamps for use in HVAC/R units or air ducts to inactivate microorganisms on irradiated surfaces, which establishes a test method for measuring the intensity of ultraviolet lamps on irradiated surfaces under typical HVAC/R operating conditions.
The document advises that new and existing healthcare waiting areas, crowded shelters, and similar facilities should go beyond the minimum requirements of the documents. The end goal is the better prepare the industry to control airborne infectious diseases (including a future pandemic caused by a new infectious agent).
Small particles remain airborne for a good amount of time and the design and operation of HVAC systems that move air can affect disease transmission. This includes supplying clean air to susceptible occupants, containing contaminated air or exhausting it to the outdoors, diluting the air in a space with cleaner air from outdoors or by filtering the air, and leaning the air within the room.
To address disease transmission, ASHRAE recommends dilution ventilation, laminar and other in-room flow regimes, differential room pressurization, personalized ventilation, source capture ventilation, filtration (central or unitary), and UVGI (upper room, in-room, and in the airstream).
ASHRAE also encourages owners, operators, and engineers to collaborate with infection prevention specialists knowledgeable about the transmission of infection in the community and the workplace. To view the full document, visit ashrae.org/COVID19.