#DIY box fan filters – #CorsiRosenthal box "Also known as a Corsi-Rosenthal box, this DIY method of building your own air filter with #MERV13 furnace filters and a box fan are an easy and cost-effective way to help clear indoor air from airborne virus particles, wildfire smoke, pollen, dust, and more! If you can seal a box, you can build one (or 100!) of these!" https://cleanaircrew.org/box-fan-filters/ #OpenSource #CleanAir #CleanAirCrew #WildfireSmoke #WildfireHaze #AQI #AirQuality #ClimateDiary #WildfireSeason #Wildfires #HEPAFilters #CorsiRosenthalBox