Foreign baby in China essentials: DIY AIR PURIFIERS

(It’s been a while since I cried on the blog about China’s air pollution. But this time we have a solution! Your salvation is at hand…)

Out our windows in Tianjin.

Our first child spent her first month outside the womb in neonatal intensive care. We brought her to China as a 4-month-old. As soon as we’d landed in Beijing the passengers sitting around us started muttering about “…污染…!” because the smog made it hard to see the terminal from the plane. Part of me wanted to take our little preemie right back to Canada.

Air purifiers were on our original list of Foreign Baby in China Essentials (along with imported formula, VPNs and friendly stranger finger shields). But I never wrote the air purifiers post because we quickly discovered that air purifiers are insultingly expensive.

Instead we moved to a less polluted city. But triple-digit air pollution is still not uncommon in Qingdao (you can see and smell anything over 100), and we do get the occasional 400 or 500+ days. Here’s what 172 looks like on a cloudless day in our neighbourhood (that mountain on the left should be crystal clear):

It’s always bothered me that we weren’t doing anything about the air aside from an outrageous amount of air-friendly house plants, especially for our kids. But thanks to PhD student Thomas Talhelm, now we can. Why I did not think of this myself I’ll never know. That’s the Fulbright scholar difference, I guess.

(Click for a larger view.)


If you can handle between $200 to $2000+ per room for commercial air purifiers, yay for you. But that’s tough to swallow for middle class peasants people like us, despite the real worry of raising young children in truly dystopic air quality. Thankfully, it’s cheap and easy to build your own air purifiers that apparently work at least as well.

Buy a pre-assembled kit from Mssr. Talhelm for .. wait for it … 33 bucks (200å…ƒ). Or get the filters and fans yourself on taobao (if you have taobao kungfu like Jessica) for 50å…ƒ less per unit. We’ve made four.

Buying the kit is obviously the most convenient way to go. But either way, a monkey could assemble these things. All you have to do is stick a HEPA filter onto the front of a fan. See how to build one here and here. You need: a fan, pliers/scissors, HEPA filter, and a strap.

“But but but… with DIY purifiers you don’t get the monitoring electronics or the aesthetics or the ionizer or all the other things we’re selling that you didn’t know you needed!” Ok, but do they work? The proles People like us are willing to sacrifice peripherals to save hundreds of dollars.

According to the results of Talhelm’s tests, which are easily reproducible for anyone who doesn’t trust people who sell things (if anyone does do their own tests please let me know!), our $25 air purifiers perform as good and possibly even better than commercial units where it counts.

(Click for the full test results.)

Despite what the high prices suggest, air purifiers aren’t magic. They blow the air in your room through a filter. It’s not like doing rocket science or trying to figure out how to make your 4-year-old not get up to pee 500 times a night.

Here’s one of ours, which cost $25:

‘If there is hope,’ wrote Winston, ‘it lies in the proles.’

About China’s apocalyptic air quality:

About having a Foreign Baby/Kid in China:

(Click to get the free China Air Pollution app.)

13 thoughts on “Foreign baby in China essentials: DIY AIR PURIFIERS”

  1. I am really excited about trying this. We have never even considered purifying the air because there’s no way we could afford it, and then we’d have to choose which room would get the clean air, etc. But this is doable! I might even rent a particle counter off of Taobao and test one myself, just for fun (it’d be interesting to test the air outside, too.

  2. This is Thomas–the nerd behind Particle Counting and Smart Air.

    That’s great! I’m so glad to hear that. My original goal was to create something so that more people can afford clean. The profits (and import taxes) on air purifiers are simply outrageous. So if this helps a few more people get clean air, I’m happy.

    Breathe safe!

    1. I think it’s great the way you guys have not taken advantage of expats who can’t speak/read Chinese by raising the price as high as you could. (…but if you give us a cut I’ll delete the bit about finding the fans cheaper on Taobao… ;) )

  3. That’s a good idea. But, I would be careful about buying HEPA filters on Taobao. When you shop on Taobao, the very first notion that should come to mind is…”fake”. And you really don’t want to take that risk with an air filter. So do some due diligence people.

      1. Thanks, Joel! Good question.

        We used our particle counter to test HEPAs from multiple manufacturers, and then we chose the HEPAs with the best results. The HEPAs we ship from Smart Air are getting over 99% of the 2.5 micron and .5 micron particles from the air going through the filter.

        1. Hi, do you ship to little bitty places in the middle of nowhere China, Like Changle, outside of Weifang? I do have an address and written in Chinese.

  4. Just don’t forget that just because a filter tested well the first time you bought it from the taobao seller doesn’t mean the one they just sent you yesterday is the same. I’ve been here 15 years, and I’ve lost count of how many times–including with air filter replacements and even from “reputable” companies–I’ve been thrown the old switcheroo. Same price; different quality. “Due diligence” in China means constant, unending vigilance every time you get one. If you don’t, you’re going to be cheated. And soon.

  5. The thing is you can go to any auto shop in China or any where or any Home accessories shop and get only HEPA-13 filter to achieve 99.95 result, also maybe can use HEPA-12 filter which with 99% result. Even if you find some smaller sized good HEPA filter then you can use wider skotch tape and tape them together side by sides like 4 pieces into 1 good bigger flat filter or 2 pieces into 1 to into good bigger sized fan.

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