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
I'm just amazed it apparently took two people to think of taping 4 air filters together with a fan on top.
Curious why it's not 5 filters with some little toilet paper tubes or something for legs. Was it found that the fifth filter is diminishing returns?
Sounds like an argument that would take at least two meetings and a dozen emails if this were done by a company lol.