HEPA Filtration
High-Efficiency Particulate Air filtration — captures at least 99.97% of particles at 0.3 microns, the hardest size to catch. Whole-home HEPA systems mount to your ductwork and clean the air in every room, not just one.
The longer answer
True HEPA is a performance standard, not a marketing label — look for certified units, not 'HEPA-type' or 'HEPA-like' filters. Whole-home HEPA bypass systems mount to ductwork and clean all supply air; portable HEPA units handle individual rooms during acute smoke events.
The smoke-season strategy layers both: a breathing MERV 11 or media-cabinet filter on the central system (fan running continuously) plus true-HEPA portables in bedrooms. A choked MERV 13 filtering trickling airflow underperforms a breathing MERV 11 — airflow matters as much as capture rating.
The Seattle angle
During Seattle's late-summer wildfire smoke season, HEPA-grade filtration is what actually clears fine smoke particulate indoors.
Guides that use this term
Where this decision happens
Nearby in the glossary
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