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Reverse engineering Xiaomi air purifier NFC stickers

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Re: Reverse engineering Xiaomi air purifier NFC stickers

#101

Post by Danieru »

5e92cb50239222b wrote: post #69
Danieru wrote: post #10

Earlier quoted context omitted.

HEPA filters get more effective overtime in exchange for more restricted airflow. Thus the failure mode is "air is not flowing" and not "air is not getting cleaned". At home I use 3 air filters in various rooms. These are standard/mid-range Japanese Sharp filters. Japanese because we live in Japan, not because Japanese HEPA filters are special. The filters themselves can be bought for about 30$ online. When the filte…

> because we live in Japan May I ask why you're using them at all? Every time I look at Japanese cities they seem to have PM2.5 levels in a second-digit microgram range. A bad day seems to be something like 15 µg.

First off I don't want to under sell Japan, it is a pretty nice country and Tokyo is pretty clean. Sadly it's still a city with car pollution all cities have.

Unique to Japan is the pollen. After WW2 Japan was reforested in mass with a single variety of tree. Thus making the exact pollen release an annual torture test for anyone without air filters. My theory is everyone eventually gets pollen alergies, it's just a matter of time. My wife is affected during pollen season, and I've starting to notice myself become affected as well.

We do not stir fry, that's not a thing in Japanese cuisine. And our cooking is all IH so no gas particle. Yet even we will notice if the air purifiers are not running. We'll first notice our noises are a bit stuffy, and omly then check to find a kid has turned off the air purifier.

An upshot to low pollution is filters last ages.

Re: Reverse engineering Xiaomi air purifier NFC stickers

#103

Post by Havoc »

muxneo wrote: post #46
qgin wrote: post #33

This is maybe the wrong place to post this, but with fire season approaching, a pretty decent high-volume air purifier can be made using filters, tape, and a box fan: https://www.texairfilters.com/a-variation-on-the-box-fan-wit...

Absolutely brilliant. Saved 100 to 300 bucks right there.

Though for some compromises. The ones that autoscale fan speed are really neat.

I've had more than one instant of airfilter going wild reminding me I had forgotten a cooking plate on

Re: Reverse engineering Xiaomi air purifier NFC stickers

#104

Post by inferiorhuman »

SemAntics0 wrote: post #63
ehPReth wrote: post #52

Earlier quoted context omitted.

curious - why is Wirecutter trash? I’ve been sorta feeling iffy about them for no real reasons but they seem highly recommended

Years ago, they really drilled into the performance of the various products they compared and frequently the winner was a specialist product from a brand you had never heard of, but it really was the best on the market. Wirecutter articles did good testing with defined rationale that might not be up to laboratory standards, but it was enough to clearly identify which products were offering the best performance. When…

I should probably start off with: yeah, I don't like the Wirecutter drill article or find it useful. They eventually call out their intended target audience:

  For most household tasks, a 12-volt drill is more than adequate. It’s the smallest
  class of drill, and due to advances in battery and motor technology, such models
  have become formidable with regards to power. … If you’re a rabid DIYer with plans
  to build a deck, a doghouse, and a tree house, we recommend a stronger, 18- or 20-
  volt drill.
They're not reviewing higher end pro tools because that's not their audience. Were pros ever looking at WC for reviews? I know that for tools I'd be looking at more specialized folks like Project Farm or Torque Test Channel.

WC did cover the popular "pro" brands available in America (Milwaukee, DeWalt, Ridgid). Potentially they should've included Makita but Festool and Hilti are way beyond the price point of the home gamer target audience. Hilti especially goes after the fleet market, so even if you're a pro they're not necessarily going to be your goto brand unless you're at a larger company. Anecdotally Milwaukee kit seems to be very popular amongst tradesmen out here. But like with circular saws there's probably some regional variation.

I think WC did miss some important stuff for home gamers and they definitely got it wrong with the Bosch drill. It's small. It's tiny. It's about as long as the DeWalt and about an inch and a half shorter in height. You don't buy it for the power you buy it for the size. If you need to stand it up on the battery, get a bigger one with a foot.

https://www.nytimes.com/wirecutter/reviews/the-best-drill-fo...

Re: Reverse engineering Xiaomi air purifier NFC stickers

#105

Post by Gigachad »

stavros wrote: post #95

Is there something that works well for cat hair? I can't stand it everywhere, but I don't know if these filters will catch them. I tried to build a box fan filter, but it moved basically no air :(

Nothing is going to be able to pull cat hair out of the air before it hits the ground without creating extreme wind.

Re: Reverse engineering Xiaomi air purifier NFC stickers

#106

Post by Reason077 »

Someone1234 wrote: post #85
BasilPH wrote: post #66

I've built dynomight's DIY filter[^1], and I love it. No DRM issues either. [^1]: https://dynomight.net/better-DIY-air-purifier.html

Very cool. Anyone seen a mod that adds activated carbon? A lot of DIY filters are very cost-effective, but the lack of activated carbon is a big downside compared to commercial solutions. There's really only two air cleaning technologies that are worthwhile right now: - HEPA filters (remove PM 2.5 particulate and above). - Activated carbon (neutralizes harmful gases). The only other thing that may be worthwhile is a…

My Philips air purifier has separate HEPA and carbon filters that can be replaced independently from each other. And also a pre-filter mesh that collects large dust particles and can be vacuumed out.

Re: Reverse engineering Xiaomi air purifier NFC stickers

#107

Post by GekkePrutser »

throwaway4good wrote: post #79
GekkePrutser wrote: post #72

Earlier quoted context omitted.

Oh ok, I heard some of them switch off for sure (after a few hours). I read this on an online forum discussing integration with Home Assistant, some users got around it by just setting an automation in Home Assistant to switch it back on again :) Which is what I would have done if my 3S had had the same problem. But it doesn't. Strange that some models are affected but others not.

Maybe it is because I am in the EU? This stuff is obviously in software and all my xiaomi gadgets get ota updates regularly.

Could be. I'm also in the EU but most stuff on my domotica vlan has no access to internet. It's possible the purifier never updated after I connected it. I know the API I use to control it with home assistant is purely local.

The forum where I read this was also EU based though. Weird.

Re: Reverse engineering Xiaomi air purifier NFC stickers

#108

Post by stavros »

Gigachad wrote: post #105
stavros wrote: post #95

Is there something that works well for cat hair? I can't stand it everywhere, but I don't know if these filters will catch them. I tried to build a box fan filter, but it moved basically no air :(

Nothing is going to be able to pull cat hair out of the air before it hits the ground without creating extreme wind.

It's fine if it hits the ground, as long as it doesn't get disturbed over and over into my food and face.

Re: Reverse engineering Xiaomi air purifier NFC stickers

#109

Post by GekkePrutser »

samstave wrote: post #38
imajoredinecon wrote: post #32

Earlier quoted context omitted.

> that 2018 scenario It’s a little hard to believe if you haven’t lived there recently, but basically the entire US west coast now has an annual fire season where you can expect at least several days of air quality in the “unhealthy” to “hazardous” range. AC (which does ~the same thing for air quality as a purifier) or a purifier is pretty much mandatory.

When the fires were raging, I was looking at all the areas air quality from purple air monitors and some areas near folsom California were at ~700 And healthy is something like <100

Healthy is far lower than 100. 100 especially indoors is really bad.
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