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In a slightly different direction than consumption, if you're worried about inhaling plastic particles: I haven't personally gotten the equipment to do actual

In a slightly different direction than consumption, if you're worried about inhaling plastic particles: I haven't personally gotten the equipment to do actual measurements yet, but I keep pet rats and they have pretty fragile respiratory systems, and anecdotally when I put together a Corsi Rosenthal Box[0] and stuck it next to their cage their allergies/sneezing pretty much entirely vanished. I still need to get air quality measuring equipment and more objectively confirm that it's working, but the research I have read suggests that spending ~$100 to put together a DYI box with good MERV13 filters or higher will solidly outperform the majority of commercial consumer-grade air purifiers out there. And subjectively, I do notice a difference in air quality, although that could be a placebo effect. Regular vacuuming will also help a lot with dust and micro-particles, but that's a lot more work than just plugging in a box fan. [0]: https://en.wikipedia.org/wiki/Corsi%E2%80%93Rosenthal_Box https://en.wikipedia.org/wiki/Corsi%E2%80%93Rosenthal_Box

x3iv130f 4y ago
Consumer grade filters have nicer fans that let them push move more air with less noise. I have multiple in my house and it's amazing how quiet they are.
- danShumway 4y ago
  Not to doubt you, but have you actually measured that they're moving the same amount of air? Circulation-to-noise ratio is something that pretty much every fan manufacturer cares about; I'm a little bit skeptical that there's an innovation here that wouldn't be applied to consumer-grade fans in general; or that you wouldn't be able to find a good box fan outside of the entry-level Walmart offerings that doesn't offer the same quality for a cheaper price. The "vornado" fans seem to get recommended a lot in this area, but I don't know if they're actually moving more air or just directing it better. Anecdotally I did look into a few fan options from purifiers that claimed to be silently moving the air, and was pretty disappointed with the specs on what I was seeing. The conclusion I drew was that increasing the size of the unit and the intake area was the best way to allow for reduced fan speed/noise/power-consumption. But it is completely possible that there's something I missed; again I haven't done my own testing.
bryceacc 4y ago
it's true that cube might outperform many commercial grade purifiers but unfortunately it's only because fires/pandemic have skyrocketed prices on purifiers and made a bunch of scammy looking ones. As you see with that box, having a filter medium and a fan is all you need. No plasma/uvc or charcoal filters necessary. I only have a couple purifiers that are $100 each and have a good centrifugal fan and a filter in front of it that can be replaced for $30. A box fan as pictured doesn't have as much static pressure to pull through the filter well, but because you have four filters worth of surface area its fine. All you could upgrade with a commercial solution is having a smaller physical footprint.
deleted 4y ago
[deleted]
sydthrowaway 4y ago
Alternatively, whats a highly rated budget air purifier that handles VOCs too ?
- danShumway 4y ago
  I haven't done a ton of research into VOCs, but my understanding is that most purifiers targeting them use activated charcoal filters? Those filters are pretty cheap, you can tape them to a Corsi-Rosenthal Box without adding much cost at all. If there's something more complicated going on then maybe that wouldn't be effective, but in general air filtration is just a combination of how much air your filter is moving and what the surface area of the filter is. In theory (I haven't confirmed) tying your own activated filters to a box fan will probably be pretty effective. A big reason why the Corsi-Rosenthal Box works so well is because there's not a lot of innovation or complexity in how good purifiers work. You just want a lot of air to go through a good filter with a sizeable surface area, so it's hard to compete with a 20 inch fan tied to 4 good filters. But again, take that with a grain of salt, maybe VOC purifiers are doing something more complicated that I'm not aware of.
  - flaviut 4y ago
    The cheap activated charcoal filters are bullshit. You can't absorb things without absorbant mass. The black plastic sponge has hardly any mass at all, period. I however do not have a good solution. I've DIY'd my own filter with charcoal pellets, but I've been unable to test it, and I'm somewhat unhappy with the design anyway.
    - bryceacc 4y ago
      correct, i remember discussion a long time ago that people would buy HVAC booster fans that look like inline duct fans and then put a giant bucket of pellets on the top of it to suck through
    - danShumway 4y ago
      Are commercial air purifiers using something better? Part of the reason I'm skeptical of the commercial market is that when I look at the teardowns of these products they're either doing something questionable where they're sacrificing air volume for noise, or they're basically using regular filters of the same or less quality that you can buy from a store. I don't doubt you at all that cheap filters work less well, but at the same time, what are the consumer-grade commercial purifiers that aren't using cheap charcoal filters? I don't think I've ever noticed an in-store purifier that took pellets, but maybe I missed something. Edit: it does make me curious if with a Corsi-Rosenthal box you could hang a non-enclosed/mesh bag/basket of charcoal pellets under the fan inside of the box and if that might produce better results than attaching charcoal filters to the sides. The obvious problem that springs to mind though is that this would make the design a lot more complicated and annoying to build. Might also result in charcoal dust spread around too, which might defeat the purpose of a purifier in the first place.

x3iv130f 4y ago

Consumer grade filters have nicer fans that let them push move more air with less noise. I have multiple in my house and it's amazing how quiet they are.

danShumway 4y ago
Not to doubt you, but have you actually measured that they're moving the same amount of air? Circulation-to-noise ratio is something that pretty much every fan manufacturer cares about; I'm a little bit skeptical that there's an innovation here that wouldn't be applied to consumer-grade fans in general; or that you wouldn't be able to find a good box fan outside of the entry-level Walmart offerings that doesn't offer the same quality for a cheaper price. The "vornado" fans seem to get recommended a lot in this area, but I don't know if they're actually moving more air or just directing it better. Anecdotally I did look into a few fan options from purifiers that claimed to be silently moving the air, and was pretty disappointed with the specs on what I was seeing. The conclusion I drew was that increasing the size of the unit and the intake area was the best way to allow for reduced fan speed/noise/power-consumption. But it is completely possible that there's something I missed; again I haven't done my own testing.

bryceacc 4y ago

it's true that cube might outperform many commercial grade purifiers but unfortunately it's only because fires/pandemic have skyrocketed prices on purifiers and made a bunch of scammy looking ones. As you see with that box, having a filter medium and a fan is all you need. No plasma/uvc or charcoal filters necessary. I only have a couple purifiers that are $100 each and have a good centrifugal fan and a filter in front of it that can be replaced for $30. A box fan as pictured doesn't have as much static pressure to pull through the filter well, but because you have four filters worth of surface area its fine. All you could upgrade with a commercial solution is having a smaller physical footprint.

deleted 4y ago

[deleted]

sydthrowaway 4y ago

Alternatively, whats a highly rated budget air purifier that handles VOCs too ?

danShumway 4y ago
I haven't done a ton of research into VOCs, but my understanding is that most purifiers targeting them use activated charcoal filters? Those filters are pretty cheap, you can tape them to a Corsi-Rosenthal Box without adding much cost at all. If there's something more complicated going on then maybe that wouldn't be effective, but in general air filtration is just a combination of how much air your filter is moving and what the surface area of the filter is. In theory (I haven't confirmed) tying your own activated filters to a box fan will probably be pretty effective. A big reason why the Corsi-Rosenthal Box works so well is because there's not a lot of innovation or complexity in how good purifiers work. You just want a lot of air to go through a good filter with a sizeable surface area, so it's hard to compete with a 20 inch fan tied to 4 good filters. But again, take that with a grain of salt, maybe VOC purifiers are doing something more complicated that I'm not aware of.
- flaviut 4y ago
  The cheap activated charcoal filters are bullshit. You can't absorb things without absorbant mass. The black plastic sponge has hardly any mass at all, period. I however do not have a good solution. I've DIY'd my own filter with charcoal pellets, but I've been unable to test it, and I'm somewhat unhappy with the design anyway.
  - bryceacc 4y ago
    correct, i remember discussion a long time ago that people would buy HVAC booster fans that look like inline duct fans and then put a giant bucket of pellets on the top of it to suck through
  - danShumway 4y ago
    Are commercial air purifiers using something better? Part of the reason I'm skeptical of the commercial market is that when I look at the teardowns of these products they're either doing something questionable where they're sacrificing air volume for noise, or they're basically using regular filters of the same or less quality that you can buy from a store. I don't doubt you at all that cheap filters work less well, but at the same time, what are the consumer-grade commercial purifiers that aren't using cheap charcoal filters? I don't think I've ever noticed an in-store purifier that took pellets, but maybe I missed something. Edit: it does make me curious if with a Corsi-Rosenthal box you could hang a non-enclosed/mesh bag/basket of charcoal pellets under the fan inside of the box and if that might produce better results than attaching charcoal filters to the sides. The obvious problem that springs to mind though is that this would make the design a lot more complicated and annoying to build. Might also result in charcoal dust spread around too, which might defeat the purpose of a purifier in the first place.