ASHRAE releases guidelines on reopening buildings


The ASHRAE Epidemic Task Force has developed guidance on how to deal with potential health risks during the reopening of buildings that were closed during the COVID-19 pandemic.

“We have reached a time where planning for a safe return to normal activities has become a priority,” said Darryl K. Boyce, P. Eng., president of ASHRAE 2019-20. “Safe operation of HVAC and building water management systems are critical components of building readiness and reopening. ASHRAE’s resources provide a framework for developing plans in a variety of building types.”

A frequently asked questions section has been set up on ASHRAE’s COVID-19 Resources.

Recommendations for building readiness and reopening include:

  • Creating a strategic plan prior to opening the building. This should include measures to make occupants feel safer, ensuring a supply chain for critical items such as filters and communication plans for building support and safety measure for occupants is in place.
  • Determine if personal protective equipment (PPE) requirements are still in place.
  • Review HVAC programing to provide flushing two hours before and post occupancy. 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 occupation.
  • Ensure that custodial scope includes proper cleaning procedures built from EPA and CDC guidance on approved products and methods.

“Key elements of a strategy to limit the spread of the COVID-19 virus are to perform needed heating, ventilating and air conditioning system maintenance, including filter changes, and to run HVAC equipment, prior to re-occupancy,” said Bill Bahnfleth, ASHRAE epidemic task force chair, ASHRAE environmental health committee voting member, and 2013-14 ASHRAE presidential member.

Decreasing water usage in buildings closed or with limited access during the pandemic can increase the risk of bacteria growth in building plumbing. Facility manager and building owners can help mitigate the risk of waterborne pathogens, such as legionella bacteria, by developing a water management plan.

The task force also recommends guidance released in the newly updated ASHRAE Position Document “Infectious Aerosols” as well as the Emerging Issues Brief.

For more information on safe building reopening, please visit


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