With the recent wildfires and the gestures broadly at the world I just wanted to share this link to the Corsi-Rosenthal Box. A simple homemade air filter that can be made with a box fan or several computer fans using off the shelf merv 13 or higher filters from your local store.
Yes, these have existed since before COVID. I had someone elsewhere get made at me because “it shouldn’t be named that! Those two didn’t invent it!” but like, I didn’t choose the name lol. Anyways, I’ve made two for my house (former hoarder house we inherited and we haven’t had the ducts cleaned yet but everything else is clean) and I can say, we both sleep better at night and they worked great through the wild fires.
Anyways, just wanted to share this as a quick little easy project. Or you know, not so quick if you wanna be like the people on Reddit’s r/CRBoxes who 3D print fancy housings and do elaborate computer fan builds. Whichever you prefer.
Edit to add: Someone posted a Build Guide (non Reddit link) on Reddit for making boxes with PC fans.
I know we don’t love Reddit links but
- Here’s a Reddit post for a DIY/buy guide
- An Information post
- A tall computer fan box
- Triangle box fan
Sorry for the Reddit links, they just have a lot of conversations going on there currently.
I haven’t heard anything about box fans overheating with the boxes on the back and I’ve been following these builds on Reddit for 2 years before I built one. The general consensus is there’s MORE air flow with the box.
Get a heat gun. You can see it happening in real time. Or not if its not.
Its good not to trust me, as I didnt put any real data on what we did here. But it should be self evident if you make the build,. run the system for a while, then check the temperature. You dont want to strap a ton of flammable material near an engine that could get hot. Also if we were to do real science, I bet its because certain fans are older/have less oil/etc…which causes a buildup of heat.