ASHRAE updates Covid guidance

USA: The ASHRAE Epidemic Task Force has updated its reopening guidance for HVAC systems to help mitigate the transmission of SARS-CoV-2. 

While the performance of many HVAC systems in buildings are still being evaluated, the new information provides major updates to the building readiness guidance.

“The Building Readiness Guide includes additional information and clarifications to assist designers and commissioning providers in performing pre- or post-occupancy flush calculations to reduce the time and energy to clear spaces of contaminants between occupancy periods,” said Wade Conlan, ASHRAE epidemic task force building readiness team lead. “New information includes the theory behind the use of equivalent outdoor air supply, method for calculating the performance of filters and air cleaners in series, and filter droplet nuclei efficiency that help evaluate the systems’ ability to flush the building.”

Major updates include pre- or post- flushing strategy methodology, flushing time calculator, and heating season guidance. Also included are adjustments to align with the recently introduced core recommendations and include minimum outdoor air supply and filter efficiency requirements and their role in an equivalent outdoor air supply-based risk mitigation strategy.

 The guidance still addresses the tactical commissioning and systems analysis needed to develop a building readiness plan, increased filtration, air cleaning strategies, domestic and plumbing water systems, and overall improvements to a systems ability to mitigate virus transmission.

The complete ASHRAE Building Readiness guide and other COVID-19 resources can be found here.