I recently stayed in an apartment that didnt have central air so I created a corsi-rosenthal box since the smoke from the Canadian wildfires were so bad.
After 30 days of continuous use, with very minimal periods of it being turned off, this is what the filters look like!
It’s disgusting yet also so satisfying to see the filters get darker from debris, dust, and dirt.
Edit: typos
TIL about the Corsi-Rosenthal Box
It is by far the best air purifier you can get for the money.
I got MERV 13 filters to help with my kids allergies. Inside the house, perfectly fine, but once outside it’s sneezing and runny noses. It’s amazing.
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.
You have to cut some cardboard and use tape too. After when your solution beat every commercial solution you are allowed to name it, just to be able to shame corpo easily.
Could use those circular filters stacked on each other and a fan at the top. Name it my column.
Didgeridoo air filter is also tempting me now.
Dongderidong air filter ?
from huppakke:
Someone posted a link to Wikipedia in the comments, came across their names:
Richard Corsi, an environmental engineer and the incoming Dean of Engineering at the University of California, Davis
Jim Rosenthal, the CEO of filter manufacturer Tex-Air Filters
take what you will from this, but it’s definitely not a stick-it-to-the-corp kinda thing
Yeah I was trying a joke. It still beat commercial alternatives which I fell is a Second good reason to give it a name.
“Corsi-Rosenthal Box” sounds like it’s some theoretical physics thought experiment, but no it’s some filters and a box fan.
Be tempted to build one of those for my shop.
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 mean, it sounds like an Einstein-Rosen bridge.
“My Corsi-Rosenthal Box is designed to efficiently accelerate particles inwards. The particles are then ‘captured’ using a special filtering technique, and separated from the air molecules which are allowed through.”
It’s removing particulates though.
So you could call it and “anti-particulate vertical fluid acceleration device” maybe.
I thought it was for filtering weed smoke, designed by the famous grower and strain creator Ed Rosenthal Ed Rosenthal.
Think it was a covid thing.
No word on ed being the rosenthal in question.
Someone posted a link to Wikipedia in the comments, came across their names:
Richard Corsi, an environmental engineer and the incoming Dean of Engineering at the University of California, Davis
Jim Rosenthal, the CEO of filter manufacturer Tex-Air Filters
Oh, that’s disappointing.
could be his brother
Not the weed guy though.
Oh. A CEO of a filter company. I sort of wondered why I couldn’t just tape a single filter to a fan, why it required four of them. Maybe it has something to do with air flow limitations, or maybe it has something to do with the guy making a profit on every filter sold lol
Pretty sure its about creating negative suction below the fan. Instead of just pulling air from the intake side of the fan, its pulling it from all 4 directions. Theoretically the air flow going through the filter would be at least 4x but probably more in practice.
Well the rate of airflow through the fan is at its maximum when there are no filters attached to it. Each filter likely slows down airflow if hooked up in a “series” pattern, but you’re right that having these four in “parallel” will increase flow compared to one strapped directly to it. I’m sure there’s a problem with reducing the airflow too much, because the fans motor would start to burn, and I’d guess that hoisting the fan up in the air rather than standing upright on the ground would improve airflow.
That being said, I’d need to do it myself and see what strapping a single filter to a fan does. I have hunch it wouldn’t burn out the motor, and I imagine it’d still be effective. If the rate of airflow isn’t severely reduced with a single filter, that’d just mean the same amount of air is being forced through a filter in either case (1 vs 4 filters).
Of course the single filter would wear out four times as fast so it probably won’t make a difference in how many you buy in the long run. I’m just sort of rambling at this point but it’s a neat concept to think about.
These have been around for a long time as DIY filters for folks, I remember seeing one of these on Reddit before comments were a thing.
Once upon a time Reddit drove you to interact with other websites instead of shitposting your best hot take about the title of the post someone else didn’t even visit.
Comments truly ruined Reddit
Long time ago I made my own activated carbon filter from plans I found online out of chicken wire, some duct parts, of course activated carbon, and pantyhose. got some funny looks when buying that last one, but it worked like a freaking charm.
custom filters are common in the aquarium hobby, lots of fun pipe fittings to play with
That a good idea ! Didn’t think about it.
well…
A 2022 study found the clean air delivery rate on the five-filter design was between 600 and 850 cubic feet (17–24 m3) per minute (depending on fan speed), costing roughly a tenth of commercial air filters.
hope you can keep up!
Yeah may be a little overkill
Now imagine that, but in your lungs. Yikes.
lungs are self cleaning, dirt just dosent stay in there it gets pushed out again by tiny moving hairs
… mostly into your stomach.
I have great news for you about what happens to the contents of the stomach!
It also gets pushed out! (Normally)
dont worry they mix with the microplastics down there
I mean, yes.
But like, they have to, without the filter.
Some dirt gets pushed out and sum just stays
I totally did not realize how much real science was behind these things. I mean this design is so simple and obvious, it seems like something I would throw together because it just looks like it “should” work. And according to the research I just read they are very efficient and effective. Super cool!!!
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
This is a great reminder to clean my computer fans.
make sure you get merv 13 or higher for smoke. the filters get gross fast even with 8 but you can tell the difference when you breathe.
I have 2 to 4 of these going at all times and the 8s are full time and 13+ are periodic unless fire season.
Hey, I have that same rug
It really ties the room together
Yeah, well, you know, that’s just, like, your opinion, man.
I have the same box fan
i have the same duct tape
Will all of you get out of my house?!?!
Nope, the air is good here. Have any beer?
I saw a couple left in the fridge. Will you grab more chips while you’re up, please?
Do you have the link for it? So we can all have one.
You’re not a true lemmy unless you own The Rug
Lemmy’s ‘Upvote Soup’?
I got it from my parents after they didn’t want it anymore, but I think they got it from IKEA
Christ i wish we could get these filters in au at non-arserapey prices
I read that as “our-SER-uh-pee” at first. I now have a new adjective.
Say it in a pirate accent
Theres a way i bet. You just need the filter dimensions to match the fan on one axis.
Can you order from Alibaba?
Filtering can be a rabbit hole.
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.
Flexible weather stripping for doors is good for this.
Ohhhhh that’s a great idea! Thanks for the suggestion!
Post a new one for comparison.
You can eference the outer edges for a satisfying before/after.
Now it matches the rug & walls, though
Funny enough I cleaned that rug after first moving in (apartment was pre-furnished) and it looked clean for a whole day.
I feel ya. My house was miles away from the evacuation zone of the PacNW fires a little ways back, and the filters didn’t last the month. We wore masks with filters rated for smoke whenever we had to go outside, and sealed every external seam, hoping the firefighters could get it under control in time. Thankfully, they’re the public servants that actually know what that phrase means, and to the enth degree. I trust every one of them right alongside our Nat’l Park service members (rangers, et al), sight unseen.
When this nation’s collapse comes to your town, remember this simple rule, fellow US peeps:
Firefighters & National Park Service? Heroes of the people, through & through.
Cops, etc.? Shoot on sight (if that’s your chosen theme for the apoc, ofc.) 😅
I really need to make one of these.
Good job, Captain Lovell. That’s some Apollo 13-level engineering right there.
Just doing my part ground control 🫡
Can you talk about how you made this
It’s literally what you see in the picture. Just household furnace filters taped into a box with a fan. You can pick your level of filtration with the type of filters you buy.
Does the fan suck or blow, and why? I seem to recall that the motor will burn out if you face it the wrong way.
Looks like it’s sucking air through the filters.
I would imagine it blows upwards, so it sucks in air through the filters and blows clean air up.
In that pic it’s blowing up, sucking intake through the filters and blowing filtered air into the room.
It is setup to pull in air through the filters into the box and push it up through the top.
UC Davis has a video on how to build one.
I built one back when I lived in California during fire season, and then again during the pandemic. They do such a nice job making the air less gross.
I think that’s about what mine looked like after 3 or 4 weeks too…
