ASHRAE recently approved publication of its highly anticipated standard to reduce the risk of airborne infectious aerosol transmission in buildings.
ASHRAE Standard 241, Control of Infectious Aerosols establishes minimum requirements to reduce the risk of disease transmission by exposure to infectious aerosols in new buildings, existing buildings, and major renovations. Infectious aerosols are tiny, exhaled particles that can carry pathogens that cause infections or disease.
Infectious aerosols are so small that they can remain in the air for long periods of time. Use of this standard could reduce exposure to the SARS-COVID-2 virus, which causes COVID-19, the flu virus, and other pathogens.
Standard 241 provides requirements for many aspects of air system design, installation, operation, and maintenance. It includes an infection risk management mode (IRMM) that enhances the normal mode of operation via engineering controls to reduce infectious aerosol exposure of occupants. It also provides a Requirements for Use of Filtration and Air Cleaning Technology section that outlines how to draw in additional outdoor air to ventilate a building in an energy-efficient, cost-effective manner.
More on the standard from ASHRAE:
Important aspects of the standard include:
- Infection Risk Management Mode – Requirements of Standard 241 apply during an infection risk management mode (IRMM) that applies during identified periods of elevated risk of disease transmission. AHJs (Authorities Having Jurisdiction) can determine when the enhanced protections of Standard 241 will be required, but its use can also be at the discretion of the owner/operator at other times, for example, during influenza season. This aspect of Standard 241 introduces the concept of resilience – ability to respond to extreme circumstances outside normal conditions - into the realm of indoor air quality control design and operation.
- Requirements for Equivalent Clean Airflow Rate – Other indoor air quality standards, including ASHRAE Standards 62.1, 62.2, specify outdoor airflow rate and filtration requirements to control normal indoor air contaminants. Standard 241 breaks new ground by setting requirements for equivalent clean airflow rate, the flow rate of pathogen free air flow into occupied areas of a building that would have the same effect as the total of outdoor air, filtration of indoor air, and air disinfection by technologies such as germicidal ultraviolet light. This approach allows the user of the standard flexibility to select combinations of technologies to comply with the standard that best satisfy their economic constraints and energy use goals.
- Requirements for Use of Filtration and Air cleaning Technology – Dilution of indoor air contaminants by ventilation with outdoor air can be an energy intensive and expensive way to control indoor air quality. Standard 241 provides extensive requirements for use of filtration and air cleaning to effectively and safely achieve meet equivalent clean airflow requirements efficiently and cost effectively. These include testing requirements to establish performance and to demonstrate that operation does not degrade indoor air quality in other ways, for example by elevating ozone levels.
- Planning and Commissioning – Standard 241 provides assessment and planning requirements culminating in the development of a building readiness plan, a concept carried over from the work of the ASHRAE Epidemic Task Force. It also describes procedures for commissioning systems to determine their installed performance.
The standard is available for presale in the ASHRAE Bookstore.
Related Stories
Codes and Standards | Jul 15, 2024
New York City code update changes definition of a major building
Changes affecting how construction projects in New York City are permitted will have significant impacts for contractors. On Dec. 11, the definition of a major building in the city’s code will change from 10 stories to seven, or 75 feet. The change will affect thousands more projects.
Government Buildings | Jul 8, 2024
GSA adopts new accessibility guidelines for federal properties
The U.S. General Services Administration (GSA) adopted a new rule with new accessibility guidelines for federal buildings. The rule establishes that pedestrian facilities in the public right-of-way are readily accessible to and usable by people with disabilities.
Sustainability | Jul 1, 2024
Amazon, JPMorgan Chase among companies collaborating with ILFI to advance carbon verification
Four companies (Amazon, JPMorgan Chase, JLL, and Prologis) are working with the International Living Future Institute to support development of new versions of Zero Carbon Certification.
K-12 Schools | Jul 1, 2024
New guidelines for securing schools and community spaces released by the Door Security and Safety Foundation
The Door Security and Safety Foundation (DSSF), in collaboration with Door and Hardware Institute (DHI), recently released of “Are Your Door Openings Secure?.” The document provides guidelines to equip school administrators, building management personnel, and community leaders with a clear roadmap to create a secure and safe environment.
Sustainability | Jun 24, 2024
CBRE to use Climate X platform to help clients calculate climate-related risks
CBRE will use risk analysis platform Climate X to provide climate risk data to commercial renters and property owners. The agreement will help clients calculate climate-related risks and return on investments for retrofits or acquisitions that can boost resiliency.
Codes and Standards | Jun 17, 2024
Federal government releases national definition of a zero emissions building
The U.S. Department of Energy has released a new national definition of a zero emissions building. The definition is intended to provide industry guidance to support new and existing commercial and residential buildings to move towards zero emissions across the entire building sector, DOE says.
Healthcare Facilities | May 28, 2024
Healthcare design: How to improve the parking experience for patients and families
Parking is likely a patient’s—and their families—first and last touch with a healthcare facility. As such, the arrival and departure parking experience can have a profound impact on their experience with the healthcare facility, writes Beth Bryan, PE, PTOE, PTP, STP2, Principal, Project Manager, Walter P Moore.
MFPRO+ News | May 28, 2024
ENERGY STAR NextGen Certification for New Homes and Apartments launched
The U.S. Environmental Protection Agency recently launched ENERGY STAR NextGen Certified Homes and Apartments, a voluntary certification program for new residential buildings. The program will increase national energy and emissions savings by accelerating the building industry’s adoption of advanced, energy-efficient technologies, according to an EPA news release.
MFPRO+ News | May 20, 2024
Florida condo market roiled by structural safety standards law
A Florida law enacted after the Surfside condo tower collapse is causing turmoil in the condominium market. The law, which requires buildings to meet certain structural safety standards, is forcing condo associations to assess hefty fees to make repairs on older properties. In some cases, the cost per unit runs into six figures.
Codes and Standards | May 10, 2024
Guide on electrifying space heating for large commercial buildings with boilers released
The U.S. Department of Energy has released a guide on electrifying space heating for large commercial buildings with boilers. The guide summarizes key considerations for people seeking to retrofit existing large commercial and multifamily buildings, particularly those that currently heat spaces using fossil fuel-fired boilers.