Anyone heard about Corsi-Rosenthal boxes? https://cleanaircrew.org/box-fan-filters/ https://cleanaircrew.org/box-fan-filters/. A box fan and 4 x 2 inch MERV 13

Anyone heard about Corsi-Rosenthal boxes? https://cleanaircrew.org/box-fan-filters/ https://cleanaircrew.org/box-fan-filters/. A box fan and 4 x 2 inch MERV 13 filters. Around $100, including the duct tape. This design is very effective, surpassing commercial air cleaners that are three times more expensive in independent tests. https://cleanaircrew.org/ufaq/does-the-corsi-rosenthal-box-work/ https://cleanaircrew.org/ufaq/does-the-corsi-rosenthal-box-w....