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Build Your Own Air Filter System

Clear indoor air with do-it-yourself (DIY) air filtration boxes.

The air filter, named the Corsi-Rosenthal Box, is low-cost, easy to assemble and effective. It was first created when Richard Corsi, Dean of the Engineering School at UC Davis, suggested the idea on Twitter, and Jim Rosenthal, owner of Tex-Air Filters, built the first box in response. The materials—a box fan, 4 or 5 MERV-13 filters and duct tape—cost somewhere between $70 and $120, and the box is designed to last six months.

Use this method to build your own air filter with MERV13 furnace filters and a box fan. This easy DIY project is a cost-effective way to help clear indoor air. 

(Important: Fans purchased for this project must be 2012 or newer for electrical/fire safety reasons. Also, make sure to turn off fans when finished and do not leave them running unattended.) 

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