Standard MERV 8 filters, commonly found in residential and commercial HVAC units, are designed for dust and pet dander rather than the microscopic PM2.5 particulates generated by wildfires. According to Dr. Jon Rajala, Manager of Research & Development at AAF International, upgrading to a MERV 13 filter can reduce exposure to these hazardous particles by 75% to 80%. These particulates are particularly dangerous because they can penetrate deep into the lungs and enter the bloodstream, posing significant risks to those with asthma, heart disease, or COPD.

With air quality alerts active from Pennsylvania to Massachusetts, experts warn that the danger does not vanish when the sky clears. Research from Harvard’s T.H. Chan School of Public Health indicates that cardiorespiratory effects from wildfire smoke can persist for months. Consequently, AAF advises replacing filters immediately after smoke dissipates, even if the filter appears clean. Before making the switch, homeowners should verify that their HVAC systems can handle the increased airflow resistance of higher-rated media. In addition to upgrading filters, experts recommend sealing windows and doors, running portable air purifiers, and considering carbon-based filters to neutralize lingering odors and volatile organic compounds.