Arkansas HVACR NewsMagazine May 2021

HVACR NewsMagazine May 2021

State National Chapter News

Threat Posed by Airborne Transmission

High-efficiency filtration goes mainstream

When a contagious person sneezes, coughs, talks, or even breathes, infectious particles spread throughout the room and contaminate the air in it. However, those same particles can enter the return air ducts of the HVAC system, which then circulates those particles throughout a building.

Chris Plotz, Johns Manville

Photo courtesy of BanksPhotos/iStock

Clean Air Is the Answer The solution to this problem, as recommended by ASHRAE, involves diluting the concentration of infectious particles with increased amounts of outside air, and cleaning the air with filters with an efficiency rating of at least MERV 13.

As a result of the COVID-19 pandemic, high-efficiency filtration is making significant inroads in awareness and use in commercial and residential settings. Air filters are rated for how effective they are at removing a range of particles – from very small particles to larger particles that are visible to the human eye. The MERV rating for HVAC filters is an acronym for Minimum Efficiency Reporting Value. This rating is determined by filter manufactures in accordance with ASHRAE 52.2 – which is the method of testing general ventilation air-cleaning devices for removal efficiency by particle size. Prior to the COVID pandemic, office building and residential air filtration was typically utilizing MERV 8- to MERV 10- rated filters. However, protection against certain airborne particulate, as well as the SARS CoV-2 virus, can be enhanced by including filters with higher MERV filtration rates. In light of the COVID-19 pandemic, the U.S. Centers for Disease

Upgrading from a MERV 7 air filter to a MERV 13 filter reduces the likelihood of infection by nearly 40% .