Microscopic image of pathogens

New ASHRAE Standard 241 Targets Infectious Aerosols

Following a consensus-based process, ASHRAE has published its first pathogen-mitigation standard.  ASRAE Standard 241, “Control of Infectious Aerosols,” aims to reduce the risk of airborne disease such as SARS-COV2 (which causes COVID-19), influenza, and other pathogens in both residential and commercial buildings.

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,” Farooq Mehboob, ASHRAE’s 2022-23 president, said following completion of the draft standard. “Nowhere in the world do we have a standard that universally addresses the concept of mitigating pathogen spread and IAQ and ASHRAE is proud to lead in the development of the guidance.”

According to ASHRAE, Standard 241 establishes requirements for IRMM—Infection Rick Management Mode­—for enhanced protection during times of elevated disease transmission, requirements for equivalent clean airflow rate targets per occupant of pathogen free air flow, and requirements for use of filtration and air cleaning (HEPA filters, air ionizers, UV lights, etc.) to achieve equivalent clean airflow requirements. The standard also provides a building readiness plan outlining procedures for assessing new and existing HVAC systems for times of increased disease-causing pathogen transmissions.

By adhering to Standard 241, building owners and operators can effectively reduce exposure to various pathogens, including the SARS-COV-2 virus responsible for COVID-19, as well as influenza viruses and other disease-causing agents that inflict significant personal and economic damage each year


Because the standard requires significantly higher ventilation rates when viruses are active, it’s further support for investing in equipment with higher-than-minimum code-required capacities, along with proper controls that ensure airflow is optimized for current conditions.

Systemair’s air handling units offer a number of opportunities to enhance protection against viruses. For example, our DELTRI+ filters contain advanced plasma technology capable of neutralizing or destroying 99% of all viruses, including SARS-CoV-2. DELTRI+ filters are available as an optional accessory item for all new or installed Systemair Geniox and Topvex air handling units, as well as replacement filters in standard sizes for existing air handling units, regardless of the brand.

To learn more about and purchase ASHRAE Standard 241, click here.

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