Today, I was asked about effective air cleaners, because wildfires have already begun to flare in North America.

Extensive global testing has found that a DIY #CorsiRosenthalBox will outperform almost every commercial HEPA unit while costing less to run.

For the US & Canada, the best source of filters to build one is Costco: Filtrete 1900, 2200, or 2500 models with at least one 20-inch dimension.

These units also help mitigate allergens and infectious aerosols like #Covid and Influenza.

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