alt Hacker NewsBased on personal experience, HEPA isn't even necessary when you're filtering that much air.
My house downwind of a freeway and a wilderness area, lots of nasty black tire dust mixed with allergens. It did not come with A/C. I had HEPA air purifiers around the house that I would leave in auto mode and they would run for a few hours a day based on the air quality.
Then I got central A/C installed with a standard 1" MERV 10 rated filter on the intake. Just running the blower for 10 minutes every hour is enough to keep the air quality in every room below the level where the air purifiers would kick on. I've given most of them away.
100%. Understanding your air quality is important, since it can vary greatly based on so many factors, some other ones can be location, home type (condo, house), occupant types (seniors, small humans), health conditions (allergies, etc), homes don't always share the same kind of air circulation.