August 27, 2020

ASHRAE Updates Guidance to Mitigate Transmission of SARS-CoV-2 as Buildings Reopen

Updates to ASHRAE’s “building readiness” document address guidance for heating, ventilating, and air conditioning (HVAC) systems intended to help mitigate the transmission of SARS-CoV-2 as buildings reopen during the COVID-19 pandemic. One goal of the ASHRAE Epidemic Task Force, which updated the guidance, was to provide “information and clarifications so that owners can avoid operating their HVAC systems 24/7.” For example, the task force updated recommendations related to the pre- and post-flushing strategy, which is intended to ensure that a building’s ventilation schedule assists in removing bioburden before, during, and after occupancy. According to ASHRAE’s guidance, buildings should be “flushed for a duration sufficient to reduce concentration of airborne infectious particles by 95 [percent].”

ASHRAE also updated recommendations related to the operation of energy recovery ventilation systems and building readiness modes of operation. The guidance considers several situations for buildings operating in epidemic conditions, including buildings that are occupied at pre-epidemic capacity, occupied at reduced capacity, and temporarily unoccupied. ASHRAE’s guidance also discusses operation during building closure for indefinite periods.

Building owners and operators will find guidance related to the development of a building readiness plan, increased filtration, air-cleaning strategies, domestic and plumbing water systems, and system improvements to mitigate virus transmission.

The complete building readiness guide is available as a PDF.

Other COVID-19 response resources from ASHRAE, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, are collected on the society’s website.