A DIY air purifier built from box fans and furnace filters, the Corsi-Rosenthal Box delivers performance that rivals commercial units at a fraction of the cost. Both Reddit and RTINGS.com recommend it for large, unoccupied spaces like workshops and basements.
If you're covering a workshop, garage, or any large utilitarian space and don't want to spend $300+ on a commercial unit, just build a Corsi-Rosenthal Box — it genuinely works and the internet has proven it repeatedly.
“If you're looking for a good air purifier in an otherwise unoccupied space, a traditional Corsi-Rosenthal box is going to be one of the best”