I like this idea

Corsi-Rosenthal box Here's mine. Works like a charm

I gotta do this

The plans were like $5

You can interchange the fan. Which is controversial in the forums. Meaning you shouldn't blow into the box. @The3DHandyman goes into a lot about these boxes

@washghost1 Don't know off the top of my head. It's a caterpillar circular fan from Amazon

@ThisOldHouse made a better one

We do that in the shop when we are cutting wood

Smart

@drilltheshills Used one during heavy fire season and few times. Brand new filter would be tar brown after a day or so.

@washghost1 Smoke is a whole different problem.

The Corsi Rosenthal box, which has 4 filters to 1 box fan, instead of 1:1, is FAR superior to this. The CR box has also been scientifically tested & proven to work over the years.

Lasko sells this as an all in one unit btw It’s a lasko box fan with a holder for a standard furnace filter Looks cleaner than tape

Been a thing in woodworking for ages

Did this last summer. And it’s sold by Walmart

Actually quite brilliant!

@the_dailydrop It is

I really love all the comments about why this doesn’t work.🙄There is dust in the filter, so it seems to work and she is happy. Just let the people who use this system have their win and move on to the next post no need to be say anything.

better and won't burn out the fan

Love my #corsirosenthalbox one of the most cost effective/efficient air purifiers!

This is a DIY hack, and I'm not going to knock it. As a journeyman HVAC installer I will make this one critical suggestion. DO NOT!! Apply this directly to the back of the fan like this. Leave the filter about an inch away and seal around it. This will avoid airway restriction.

Use charcoal filters for all your vents in your house! Works awesome!!

This doesn't work the same, sorry lady. It's a good idea, no legit, but it doesn't purify the air. You need a carbon filter to really do want you want.

white people in 2016: white people in 2026: "were doing GREAT"

We don’t have dust for 5 years, loving these

Outperforms $1,000 HEPA filtration systems! I run 2 in my classroom. Science in Action: How to Build a Corsi-Rosenthal Box | College of Engineering

I leared something today!...⬅️See what I did there?! lol. This is pretty cool!

Found it (affiliated link)

Available here @grok draw it on a table

Found it (Affiliated Link)

Someone made an air filter out of five filters in the shape of a cube. The top side was replaced with a box fan and it purportedly did a better job than machines that cost hundreds of dollars.

C-R box = Corsi-Rosenthal box. There are a few pics of them in this thread.

Good way to burn a fan up.

Found it (Affiliated Link)

Uummm….🤔

I've been running these for years for my parrot (he gets dusty between showers). I have cheap box fans that have been running since 2018, no issues, and they do filter the air. ...to counter the comments saying it won't work.

She said one of those filters you put in the airways to the house LOL It's a furnace lmao

Not a bad idea at all, and far better than using overly restrictive filters in your HVAC equipment, which can cause problems by restricting air flow. Never use higher than a MERV 8 rating in your HVAC equipment unless it specifically calls for it. 😉

We lived pretty close to the forest fires in the Pacific NW and it was getting pretty smoky even inside the house. I set up a box fan with a filter (don't actually need to tape it though) and went through a filter about 1-2 days. It picked up an insane amount of particles.

It works well. I did a video about it a couple years ago for dust control.

I actually really like that