Videos
The honest science of clean air — no brands, nothing to sell you. Each topic is a short read, with the video where you can watch it in action.
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Why “99.97% HEPA” Doesn’t Mean Your Air Gets Clean
“99.97% HEPA” is on almost every air purifier box — and it’s almost useless on its own. Here’s what that number hides, and the one figure (CADR) you should read instead.
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Never Vacuum Your Air Purifier Filter — A Biologist Explains Why
Vacuuming a HEPA filter to 'save money' does two things, both bad: it tears the fibres so it stops filtering, and it re-releases the dust, pollen and mould spores it spent months trapping back into your air.
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The DIY Box That Out-Cleans Purifiers 5× Its Price
A Corsi-Rosenthal box — a box fan plus a few flat MERV-13 filters — delivers more clean air than most purifiers costing five times more, and you clean it by simply swapping a flat panel.
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