The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has released the ASHRAE Standard 241, Control of Infectious Aerosols, a new publication detailing airborne infection risk mitigation for buildings. The publication establishes minimum requirements to reduce the risk of disease transmission by exposure to infectious aerosols in new buildings, existing buildings, and major renovations.

Aerosols are tiny, exhaled particles that can carry disease-causing pathogens that can be inhaled and remain in the air for long periods of time.

Use of Standard 241 would reduce exposure to the SARS-COV-2 virus – the virus that causes COVID-19, influenza (flu), and other pathogens that cause major personal and societal damage. The standard provides requirements for aspects of air system design, installation, operation, and maintenance. Some of the important aspects include:

• Infection Risk Management Mode – identified periods of elevated risk of disease transmission.
• Requirements for Equivalent Clean Airflow Rate – airflow rate and filtration requirements control normal indoor air contaminants; equivalent clean airflow rate, allows flexibility to select combinations of technologies to comply with the standard.
• Requirements for Use of Filtration and Air Cleaning Technology - requirements to meet equivalent clean airflow requirements as efficiently and cost effectively as possible.
• Planning and Commissioning – procedures for commissioning systems to determine their installed performance.

By implementing the requirements outlined in Standard 241, indoor environments can be made healthier for building occupants. The standard also promotes sustainable practices and empowers building owners and operators to take proactive measures in safeguarding indoor environments.

ASHRAE Presidential Fellow and Standard Project Committee 241 Chair William Bahnfleth, PhD, P.E., said this [standard] is a significant achievement and milestone in connecting building design and operation with public health.

Standard 241 is available now for sale in the ASHRAE bookstore.