HVAC and COVID-19 (UPDATE)
ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning Engineers has released recommendations for reopening buildings that have been shut down due to COVID-19. Their recommendations for building readiness and reopening are as follows:
- Create a strategic plan prior to opening a building. The plan should include measures to make occupants feel safer, ensuring supply chain for critical items such as filters and communication plans for building support and safety measures for occupants.
- If the building opening takes place when Personal Protective Equipment (PPE) requirements are still in place, ASHRAE’s Occupancy Guides can be referenced to deal with functioning buildings during the epidemic.
- Review HVAC programming to provide flushing two hours before and post occupancies. This includes operating the exhaust fans as well as opening the outside air dampers. For buildings without the capacity to treat large quantities of outside air and when outside air conditions are moderate, open all windows for a minimum of two hours before reoccupation.
- Ensure that custodial scope includes proper cleaning procedures built from EPA and CDC guidance on approved products and methods:
- Disinfect high-touch areas of HVAC and other building service systems (e.g. on/off switches, thermostats)
- Disinfect the interior of refrigerated devices, e.g. refrigerators, where the virus can potentially survive for long periods of time.
- Run the system on minimum outside air when unoccupied.
- Garage exhaust, if any, should run two hours before occupancy.
“Key elements of a strategy to limit the spread of the COVID-19 virus are to perform needed heating, ventilating and air conditioning (HVAC) system maintenance, including filter changes, and to run HVAC equipment, prior to re-occupancy,” said ASHRAE Epidemic Task Force chair, ASHRAE Environmental Health Committee voting member and 2013-14 ASHRAE Presidential Member Bill Bahnfleth.
A decrease in water usage in buildings closed or with limited access during the pandemic can increase the risk of bacteria growth in building plumbing and associated equipment. Facility managers and building owners can help mitigate the risk of waterborne pathogens, such as Legionella bacteria, the cause of Legionnaire’s disease, by developing a water management plan. ANSI/ASHRAE Standard 188-2018, Legionellosis: Risk Management for Building Water Systems establishes minimum legionellosis risk management requirements for building water systems.
Please also see our previous post regarding HVAC and COVID-19 for additional information.