A first-ever standard for mitigating the airborne spread of infectious pathogens in indoor spaces has been released for public review. ASHRAE standard 241P sets out minimum HVAC-related requirements for a range of occupancies including residential, office, classroom, hospitality, and health care spaces.

“The entire world was touched by the effects of the pandemic and we learned that an effective way to protect ourselves from the spread of pathogens is to improve the indoor air quality and ventilation in the buildings that we occupy,” says Farooq Mehboob, 2022-23 ASHRAE president.

The standard addresses the installation, commissioning, operation and maintenance of ventilation and filtration systems to reduce long-range transmission of infectious aerosols. It also includes specifications of air-cleaning system design. It establishes minimum thresholds for equivalent outdoor air in 13 categories of occupancy, and provides guidance for developing building readiness plans and HVAC system operation in during periods of high risk.

The new standard is built on many of the experiences of the COVID-19 pandemic and related guidance from ASHRAE’s epidemic task force. It applies to both new and existing buildings.

“It is a ground-breaking document that we expect to have significant impact. We look forward to the public’s comments as we work to complete the final version of the standard for publication,” says William Bahnfleth, who chaired the 241P standard development committee.

Comments will be accepted until May 26, and the standard is slated to be finalized this summer.