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.
Variations of this idea are genuienly vital health/survival info, right now, and will continue to be going forward.
Yes, one particular design may or may not be more effective than the other, but the basic concept of ‘duct tape a HEPA filter onto a box fan’ is absolutely a critical life hack to know if you live near anywhere that does or can experience signifcantly degraded air quality.
It isn’t perfect, but it immensely better than doing nothing, and most importantly, it is not horrendously cost prohibitive (at least currently, jfc).
Walking around for 30 minutes in wildfire smoke is roughly equivalent to smoking a couple of packs of cigarrettes.
You probably do not want to be inhaling that shit all day long, for many days at a time, if you live in a home/building that does not have its own air purification system.
Chances are you probably don’t have air filtration. Having AC often does not mean you also have filtration.
So have these things on hand, or ready to assemble, when a wildfire smoke plume or something decides your city is especially beautiful to it.
Fires and smoke can come fast, suddenly, with relatively little warning.
Be prepared.