I'm going to start talking in vague terms about my own designs for a "Corsi-Rosenthal Box" when I want to sound smart.

It'll be great if anyone bothers to look it up.

I thought it was for filtering weed smoke, designed by the famous grower and strain creator Ed Rosenthal.

It is by far the best air purifier you can get for the money.

Been aware of the general idea for a long time, but had no idea that strapping HEPA filters to a fan has a fancy name.

I think the science comes in showing that it does actually work. Like, this is so simple of an idea that I would be skeptical of if it would work if I had had the idea by myself. I'm glad that I live in a world where, if I had thought of this and wondered "is this a good idea, or am I just being dumb for thinking something so simple could work?", I am able to go online and find information and guides on this and other diy filters

correct me if I'm wrong but anything higher than MERV 13 has diminishing returns because of increased resistance. instead of going for increased MERV I recommend getting thicker MERV 13 because of their bigger surface area.

CR boxes rely on raw total air volume and increased ACH vs HEPA which relies on filtering as much air as possible on the first pass.

I have the same box fan

They may not have been the ones who first thought of it, but the first people to publish research that shows that taping 4 air filters together with a fan works decently compared to other, non-DIY filters (where "worked decently" means does a good enough job that it's worth doing if you want a filter but can't/won't buy or build a more complex filtering system, even if it isn't as good as "proper" filtering systems)

(Tangent: I'm reminded of the "Cox-Zucker machine", a random maths thing that Cox and Zucker made together because when Cox and Zucker met at university, they realised that their names, when combined in the traditional, alphabetical order, sounded "delightfully obscene". )

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?

Ya, they were brand new filters from the store. I bought them along with the box fan and duct tape.

This apartment doesnt have a HVAC system (just wall mounted AC unit) so it's doing all the air filtration.

I buy these and swap as needed

https://www.homedepot.com/p/HDX-20-in-x-20-in-x-1-in-Standard-Pleated-Furnace-Air-Filter-FPR-5-MERV-8-12-Pack-HDXCP5-012020/332831164

Yes it can!

I was a little miffed when i went to buy the goods for this box because i couldn't get MERV 14 filters and had to settle for MERV 13.

I plan to make a frame so i can just slide filters in each side with the fan mounted on top. I'll have to figure out a means to create a nice seal between the frame and filters so the air passes through instead of around.

You can eference the outer edges for a satisfying before/after.

There's also an open source tempest that you can use a CNC for and customize to your liking with a script. https://github.com/opennukit/Nukit-Open-Air-Purifier/tree/main/Nukit%20Open%20Air%20Purifier-W(all)%20v1.0

Funny enough I cleaned that rug after first moving in (apartment was pre-furnished) and it looked clean for a whole day.

Can you order from Alibaba?

I read that as "our-SER-uh-pee" at first. I now have a new adjective.

have you heard of the Ikea Starkvind filters? they're a bit smaller but you can tape together as many as you want

Theres a way i bet. You just need the filter dimensions to match the fan on one axis.

Just doing my part ground control 🫡