I recently stayed in an apartment that didnt have central air so I created a corsi-rosenthal box since the smoke from the Canadian wildfires were so bad.
After 30 days of continuous use, with very minimal periods of it being turned off, this is what the filters look like!
It's disgusting yet also so satisfying to see the filters get darker from debris, dust, and dirt.
Edit: typos
Been aware of the general idea for a long time, but had no idea that strapping HEPA filters to a fan has a fancy name.
You have to cut some cardboard and use tape too. After when your solution beat every commercial solution you are allowed to name it, just to be able to shame corpo easily.
Could use those circular filters stacked on each other and a fan at the top. Name it my column.
Didgeridoo air filter is also tempting me now.
Dongderidong air filter ?