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Build a do-it-yourself home air purifier for about $25

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Re: Build a do-it-yourself home air purifier for about $25

#101

Post by flybrand »

blattimwind wrote: post #70
ed_balls wrote: post #52

I wonder if you'd put cotton wool, how effective it would be. Here is my set up: - I bought XIAOMI Mi Air Purifier 2 straight from China for $137.00 and spent 1 euro on a EU plug. It's so quiet that I can sleep next to it, looks nice and it's quite compact, so doesn't take up much space. It has a particle detector to adjust the fan speed. The app is useless, so a cheaper version without WiFi and bluetooth would be gr…

> I wonder if you'd put cotton wool, how effective it would be. Not very. Wet wool is better, but only as long as its wet and clean. > XIAOMI Mi Air Purifier 2 straight from China Interesting question. Does the removal of particulates offset the health impact of its cheap plastics?

Wool fiber diameters are around 20 micron - HEPA can have glass fibers below 1 micron, and big box retail grades are often 5 - 10 micron. Smaller fibers = better filters.

Re: Build a do-it-yourself home air purifier for about $25

#102

Post by gnopgnip »

apo wrote: post #90

Nifty idea, but I'm not sure I agree with the technique used to prove effectiveness: https://www.youtube.com/watch?v=kH5APw_SLUU The narrator puts a particle counter in front of the fan and notes the 90% reduction. So far so good. The problem is extrapolating this result to the entire room. Yes, maybe you'd get close to 90% if the device were allowed to run a few days. On the other hand, it could leave the situation…

This DIY version does not have the same pre filter as commercially available ones, and would need to have the filter changed more often at a minimum. There are studies showing the success such as this one. https://www.ncbi.nlm.nih.gov/pubmed/9192919

Re: Build a do-it-yourself home air purifier for about $25

#103

Post by culot »

adamwong246 wrote: post #14

I do this and it works wonders if you have pets. Tips: - run this homemade air purifier when you are vacuuming, as that tends to agitate particulates a lot - get 2 filters, a cheap low grade and a premium, high-HEPA-rated filter. Stack them together and you can replace the cheap one frequently and the expensive one less frequently.

Swedish tracing paper works well for a pre-filter. It's inexpensive for a long, seemingly inexhaustible roll, and can be washed numerous times.

It also works well by itself if you just want to cheaply filter large particulates. I used to use it in those cheap $40 Hamilton Beach air purifiers. The OEM filters for those cost almost at much as the new unit and wear out [for me] within a couple of weeks. That setup with Swedish tracing paper works well for dust, as a supplement for my HEPA filter purifier.

Re: Build a do-it-yourself home air purifier for about $25

#105

Post by emmanuel_1234 »

pat2man wrote: post #45
io_io wrote: post #38

Earlier quoted context omitted.

I have mine on a homekit enabled outlet ($20) for scheduling and presence-based triggers. Unfortunately I haven't found a homekit enabled air quality sensor to pair with it.

Eve room? https://www.evehome.com/en/eve-room

This looks great but is exclusive to Apple products (requires an iOS device)!

Re: Build a do-it-yourself home air purifier for about $25

#106

Post by hourislate »

wenc wrote: post #94

I wonder: if one is generally healthy and the air quality is unproblematic, should one get an air filter? Does air filtration potentially lower long term immunity and make us less tolerant to particulates? I worry about the long term effects of being “too clean”, that is, I think there’s something to hygiene theory of disease. The body needs small stressors and perturbations in order to thrive.

I wouldn't worry about this if you live in a city. The amount of vehicle exhaust, brake dust, and just general stuff in the air will make up for and most likely counter the time you spend in a clean breathing environment.

Re: Build a do-it-yourself home air purifier for about $25

#107

Post by buzzy_hacker »

abalone wrote: post #82

Can we talk about Molekule? Their team and some SF tech community folks have been plugging it all over Twitter during this tragic wildfire crisis. But it seems like snake oil to me. It’s $800. Certainly for smoke particles it can’t possibly offer any more protection than a standard HEPA filter. But even for its claimed ability to nuke VOCs, the claim seems ridiculous. While particles can deterioriate under prolonged…

I agree it seems sketchy. NYTimes writes, “Unlike virtually all other air purifiers—and all we’ve tested—Molekule is not HEPA-rated and does not claim to eliminate micron-scale particulates with a filter. Instead it claims to remove smaller, nanoscale pollutants, including VOCs and viruses, via a chemical rather than a physical process. Out of curiosity, we requested a model for testing for VOC reduction, but Molekule requested conditions around the testing that we could not agree to.”

https://thewirecutter.com/reviews/best-air-purifier/

Re: Build a do-it-yourself home air purifier for about $25

#108

Post by HillaryBriss »

LeoPanthera wrote: post #57

Huh! I independently "invented" this myself a couple of days ago when the Camp Fire blanketed the bay area in smoke. I got a 20x20 filter and some duct tape from Home Depot and a box fan from Target. (After discovering that Home Depot only sells fans in the summer.) I don't think I was the only one, though. HD was doing a brisk trade in 20x20 filters, and I think I bought the last box fan at any Target in the entire…

nice job. can you say anything about the difference it makes?

Re: Build a do-it-yourself home air purifier for about $25

#109

Post by HillaryBriss »

csours wrote: post #84
blattimwind wrote: post #70

Earlier quoted context omitted.

> I wonder if you'd put cotton wool, how effective it would be. Not very. Wet wool is better, but only as long as its wet and clean. > XIAOMI Mi Air Purifier 2 straight from China Interesting question. Does the removal of particulates offset the health impact of its cheap plastics?

Does anyone know what the actual smell of "chinesium" comes from? The smell of artificial rubber products from china, like remelt and cancer.

I bought a mechanical product like that one time and had to leave it outside for about a month before it off gassed completely

Re: Build a do-it-yourself home air purifier for about $25

#110

Post by electic »

benbojangles wrote: post #85

I built my own air purifier in 2016, living in London, I was living in a basement and was having breathing problems due to mould. My landlady was gaslighting me at the time, so I built the air purifier. It worked for a while but mould spores cling to the paper filter and eventually grow into the filter material. I think Dyson uses glass fiber filter to stop this problem. My filter helped a lot, but eventually I had s…

Woah, this is pretty scary. Thank you for sharing. How did you know it was mold that was in the air? Is there some sort of test kit that you can buy to test for this. Mold is pretty hard to detect because you can't really see it because it typically hides between the walls.

Any advice appreciated.

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