Impact of Commissioning on ASHRAE Standard 241 – Control of Infectious Aerosols

Wade H. Conlan, P.E., LEED AP, CxA, Hanson Professional Services Inc. (Maitland) presents an article “Impact of Commissioning on ASHRAE Standard 241 – Control of Infectious Aerosols” with HVAC/P magazine.

Does the commissioning authority have a part to play when it comes to implementing ASHRAE Standard 241: Control of Infectious Aerosols in new and existing facilities? Yes. In fact, there are several different services that would need to be provided for an existing facility, including testing, adjusting and balancing; building automation and more. Professionals providing these services will majorly affect how facility owners implement ASHRAE Standard 241.

To understand impact, there must be a mutual understanding on the purpose and scope of ASHRAE Standard 241. The standard states the required amount of equivalent clean air if a facility is operating in infection risk management mode, which is what facilities were doing during the COVID-19 pandemic. It
also details air cleaners’ efficiency and effectiveness, the impact of air distribution, the assessment of the HVAC system’s ability to provide equivalent clean air in IRMM, and planning and implementing engineering controls to get the systems into compliance.

Finally, it covers the system operation and maintenance requirements during IRMM. There are a few critical items for this standard; it only addresses long-range transmission. The target volume of equivalent clean air is based on achieving a low-risk level of infection for the occupant during IRMM, the
systems are assumed to be operating in accordance with the local ventilation code (e.g., ASHRAE Standard 62.1), occupancy levels are allowed to be different in IRMM than normal mode, and it is technology agnostic for engineering controls.

Editor’s Note: This topic was discussed at CxEnergy Conference & Expo. Save the date for CxEnergy 2025, to be held April 28-May 1 in Charlotte, North Carolina.