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If you are in the USA, I don't believe your claim that most commercial or schools have HEPA in their air filtration system, and know it isn't true for new resid

by coryrc 6y ago

If you are in the USA, I don't believe your claim that most commercial or schools have HEPA in their air filtration system, and know it isn't true for new residential in the PNW. The school I attended as a child didn't have any filtration at all, for example.

clairity 6y ago
there's certainly variation, regional, by quality level, as well as generational. class A commercial will almost certainly have filtered hvac, for example. my 1930's vintage high school most certainly didn't.
- coryrc 6y ago
  Filtered, yes, but not HEPA.