How to Build a Corsi-Rosenthal Box

[NoelBarlau]

I made one of these on a whim about 8 years ago to deal with the spring pollen here in Georgia. Turns out I forgot to take the time to name it after myself!

[glenesis]

I've always just slapped a 20x20 furnace filter to the intake side of a Lasko, but I needed a solution for a larger space, and this is a great idea. Thanks!

[SalivaYOUTUBE]

I use 4in thick filters for better flow and less stress on the motor over time. Also for everyone asking why not use filters on 5 sides, it's easier to find packs of 4 lol

[SkiDooRydr]

I've been doing this for a lot of years to filter sawdust in a woodshop, I wasn't even aware it had a name lol. Who decided these guys were the first ones to realize a box fan with filters on it operates like any other commercial air filter system?

[georgewuzheer]

Homie really testing the limits of his engineering degree here

[bubba]

I've been building those for years with five filters, feet, pre-filters and pretty white tape, it's actually called "The Bubba Box".

[BigFrankieC]

My only difference, was that my fan shroud was on the intake side of the fan. I used the other half of the fan box, and cut a hole in the middle of it that was 2 inches in diameter smaller than the tips of the fan blades. I think it might be a better shield to keep air from coming in the corners. I also used tape to shroud off the corners on the outflow side of the fan, just to be sure. I use 1" MERV 8 filters on the outside to catch larger dust particles and hair and stuff, then 2" MERV 13 filters for the inner core.

When we have forest fires up here in Oregon, it really clears the whole apartment in short order.

[EMleRoux]

I can't wait for them to release the video on the Corsi-Rosenthal Paper hat. - UC Davis Engineers are on the cutting edge of innovation!

[scottallen]

Wow a man that gets right down to the point no long winded conversation. Hats off to you sir very well demonstration THINK YOU !!

[scottmcm]

How long ago did this become known as a Corsi-Rosenthal box? I built a super size one these 20 years ago using wood frame with casters to hold 8 filters and a 5000 cfm drum fan. It was big but it filtered a lot of air quickly in my workshop.
The more I think about it and reed all the comments, Dr.Corsi being a dean of a College of engineering and a international expert taking credit for this idea is crazy. It would be like naming fixing a torn piece of paper with tape and calling it paper repair system".

[FCWW]

Thank goodness our Uni’s are out their reinventing the wheel. Where would we be without them!?

[bryanseitz]

Been making these for a couple years now. I use a sheet of formica cut to size for the top & bottom, and put 1/2" weather stripping around the edges of the fan.

[motomuto]

These have been around for decades. I built 1 back in the 80's to clean the air when I was cleaning the basement where I lived.

[blessedandbiwithahintofmagic]

S4A sent me here, and I'm quite happy he did <3 Thank you so much for showing me this!

[FCWW]

I’m a woodworker, and I’ve been using this for years. My grandpa had one in his workshop back in the 80’s. So…. It’s just a redneck air filter, not a Corsi-Rosenthal box.

[alexrapada]

Used this method with regular air filters during renovations. Worked really well to keep the fine construction dust to a minimum. Also helped with my allergies during windy season.

[sango_wilko]

I love how Dr. Corsi starts off by saying "What's become known as a Corsi-Rosenthal box" and then proceeds to awkwardly say "Corsi-Rosenthal box" more than a dozen times, it was like a comedy skit where can he work it in next. I remember seeing a bunch of these in New Orleans after Katrina in 2005 and the greatest benefit was that they use readily available materials which let people produce them easily in the close aftermath of storm flooding.

[Foxxorz]

All I do is plop a filter behind the fan and the suction keeps it attached. Works decent to collect dust and is a lot easier to replace the filter.

[devilman]

I made one of these out of wood years ago to help control dust in my shop.
I copied the design from someone who didn't claim to be the inventor.
Most people call this a "Box Fan Filter."

[inkblue]

I built this a month ago, its been running by my front door to protect us from my unmasked neighbors. I also have a very expensive airmega coway. This works better! In my 1000 sq ft 2 bedroom on high speed I can get PM 2.5 and PM 10 to 0. There is no way my coway could do that. It's a little loud on speed 3 so most of the time its running on 1 speed. My dog also has unexplained environmental allergies so she licks her feet and has watery eyes. It's completely cleared up now as well as my own dust allergies. Thank you so much for this!! I got my filters from costco - 3m 2200 and the box fan from Walmart, a little under a $100. My husband has a CR box running in his office where he is the only one that is masked. We are both still covid free while his entire office has had covid multiple times.