International. The ASHRAE Epidemic Working Group has developed guidance to mitigate potential health risks during the reopening of buildings closed by the COVID-19 pandemic.
"We have reached a time when planning for a safe return to normal activities has become a priority," said ASHRAE 2019-20 President Darryl K. Boyce, P.Eng. "The safe operation of HVAC and building water management systems are critical components of building preparation and reopening, and ASHRAE resources provide a framework for developing plans across a variety of building types."
ASHRAE's recommendations for reopening buildings are outlined in the FAQ section of its COVID-19 Resources webpage. Recommendations for building preparation and reopening include the following:
- Create a strategic plan before opening a building. The plan should include measures to make occupants feel safer, securing the supply chain of critical items such as filters and communication plans for building support and occupant safety measures.
- If the opening of the building takes place when personal protective equipment (PPE) requirements are still in effect, reference can be made to the ASHRAE Occupancy Guidelines for dealing with buildings in operation during the epidemic.
- Review HVAC programming to provide rinsing two hours before and after occupations. This includes operating the exhaust fans as well as opening the outdoor air dampers. For buildings without the ability to treat large amounts of outside air and when outdoor air conditions are moderate, open all windows for a minimum of two hours before reoccupying it.
- Ensure that the scope of custody includes proper cleaning procedures created 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 inside of refrigerated devices, for example, refrigerators, where the virus can potentially survive for long periods of time.
- Run the system with minimal outside air when unoccupied.
- The garage exhaust, if any, must operate two hours before occupancy.
"The key elements of a strategy to limit the spread of the COVID-19 virus are to perform the necessary maintenance of the HVAC system, including filter changes, and to operate the HVAC equipment, prior to re-occupation," said the Chair of the ASHRAE Epidemic Task Force, a voting member of the ASHRAE Environmental Health Committee and a 2013-14 ASHRAE Presidential Fellow, Bill Bahnfleth.
A decrease in water use in closed or limitedly accessible buildings during the pandemic can increase the risk of bacteria growing in building pipes and associated equipment. Facility managers and building owners can help mitigate the risk of waterborne pathogens, such as Legionella bacteria, the cause of Legionnaires' disease, by developing a water management plan. ANSI/ASHRAE 188-2018, Legionellosis: Risk Management for Building Water Systems sets minimum legionellosis risk management requirements for building water systems.
"ASHRAE's Construction Readiness Guide empowers building owners with resources and practical guidance for safer operation of HVAC systems as we make a cautious transition to a post-COVID-19 world," said the asHRAE Epidemic Task Force chair of the Construction Readiness guide, Wade Conlan.
The working group also recommends guidance published in the recently updated ASHRAE Position Paper "Infectious Aerosols" as well as in the Summary of Emerging Issues.
For extensive resources and strategies on safe reopening of buildings, visit ashrae.org/COVID19.
