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

      • baldingpudenda@lemmy.world
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        3 months ago

        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.

        • bear
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          3 months ago

          Do you know how much power it uses?

    • Korhaka@sopuli.xyz
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      3 months ago

      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.

      • Diurnambule@jlai.lu
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        3 months ago

        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.

        • Korhaka@sopuli.xyz
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          3 months ago

          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.

        • atlas@sh.itjust.works
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          3 months ago

          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

          • Diurnambule@jlai.lu
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            3 months ago

            Yeah I was trying a joke. It still beat commercial alternatives which I fell is a Second good reason to give it a name.

  • billwashere@lemmy.world
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    3 months ago

    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!!!

    • AnarchistArtificer@slrpnk.net
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      3 months ago

      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

  • Grass@sh.itjust.works
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    3 months ago

    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.

    • amino
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      3 months ago

      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.

      • Grass@sh.itjust.works
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        3 months ago

        this is true. I pick up filters from shut down businesses and warehouses sometimes when people dont know what they cost and post them to fbm or craigslist and if they are higher than 13 I also put a filter for the bottom panel since I usually hang them blowing down with cords taped at the corners. even then they start to suck inward.

  • kayzeekayzee
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    3 months ago

    Those start out white?? I think it’s time to replace mine.

    • ITeeTechMonkey@lemmy.worldOP
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      3 months ago

      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.

    • ITeeTechMonkey@lemmy.worldOP
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      3 months ago

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

      • Øπ3ŕ@lemmy.dbzer0.comBanned
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        3 months ago

        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.) 😅

  • Hello_there@fedia.io
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    3 months ago

    Ok. I’ve been looking into this a lil and there are better options than a cr box.

    Housefresh has been looking into this and they recommend the nukit tempest or luggable XL or another one - think it was a Canadian brand - as the cheapest total costs over time and lowest sound and most efficient purification. All of those use regular HVAC filters which cuts down on operating cost and are quite big which cuts down electricity and sound.

    So recommend getting one of those for long term use, if you have the space for it.

  • Toldry@lemmy.world
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    3 months ago

    I’m viewing this post with the Thunder app and I only see one photo: a box with a fan on top. I see no filter. Is there supposed to be a second photo?

  • tamman2000@lemmy.world
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    3 months ago

    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…