Fight “Crazy Bad” Air Pollution — Cheaply

hunter 31125 air purifier beijingStudents and others with limited incomes shouldn’t feel helplessly left out of the eternal expat discussion regarding air purifiers. I mentioned before but will stress again, given the recent weather: there’s a very decent and affordable Taiwan/U.S.A.-made HEPA air purifier which is perfect for small dorm rooms, offices and bedrooms. It’s the Hunter 31125 model, which you can buy for only 1238RMB at the Sundan electronics store at the Sanlitun Village. You can also order it online here. The replacement filter is also cheap, only ~140RMB every few months.

(UPDATE, Nov. 29: this model seems to be retired; read the comment section below for other low-cost options…)

This is a true HEPA filter, rated for 99.97% filtration, and reportedly is good for rooms up to ~30 square meters. In my recent piece discussing BlueAir vs IQAir, I mentioned my own personal findings regarding this Hunter purifier, which did very well. I have this in my small office, about 10 square meters, and use it 24/7. In my readings with a particle monitor that I borrowed from the IQAir team, the Hunter 31125 routinely eliminated 50-70% of pollution even with the constant door opening. At max speed with the door closed for a while, it got 91% of the pollution. These real-world percentages are quite similar to the improvements I got at home with my Blueair and IQAir machines.

By the way, do not use the ionizer setting, it’s not considered healthy anymore by most reviewers. That goes for any air purifier models.

Don’t Forget You Can Resell It

One good way to look at the cost-benefit of all air purifiers is to feel quite comfortable that all the top foreign air purifiers can be easily resold when you leave Beijing, for quite a reasonable resale value. I guess you can think of items like IQAir and Blueair as the Patek Philippe of air purifiers; you “merely look after it for the next generation”. I suppose the Hunter 31125 is more like a Honda Civic — it’s a bit boring but reliable, and if you take good care of it you can pass it along to your kids for a few more sturdy years. Most students can easily afford the Hunter 31125, use it for a year or two, and quickly resell it to another student for a high resale value.

Don’t Forget Plants, and N95 Masks

Plants aren’t nearly as efficient as a good air purifier, but they can help clean the air a bit, and they also help with industrial indoor chemicals like formaldehyde which are common here. There’s a triad of common and cheap houseplants which really help, but any plant is better than nothing.

And for all you students who bike or walk to school; you should definitely buy a few of those N95 masks and always use them during your commute when the air is bad. These masks are reusable at least a few times, and they’re only a few kuai. Most stores and pharmacies started to stock these N95 masks after the swine flu scare last year.

Want To Read More?

I have a collection of my top air pollution posts at the top of the page, but you can access it here as well.

Anyone Have Data on Other Machines?

I’m sure there are a few other lower-end HEPA models which could be fine as well, I’m simply reporting on what I’ve used. I would love readers to leave comments below discussing real-world results with other models.


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29 thoughts on “Fight “Crazy Bad” Air Pollution — Cheaply”

  1. Thanks for the article Dr. Richard.

    I have a question though, I just bought a ~500RMB YaDu air filter; one of the cylindrical models. Are they any use at all, or did I just end up with a huge paper-weight.

    1. I honestly don’t know! Perhaps there is a reliable Chinese version of Consumer Reports that has done their own independent testing of Chinese models. I do know that Yadu has a good reputation in China and I like their humidifiers. I just don’t feel comfortable recommending without seeing real data — and at 500RMB, i’m not sure how it could be a true HEPA system. I think you can call the guys at IQair or Blueair and they can come over and test your house’s pollution readings…

    1. At low-mid levels, all are quiet-ish, in my opinion. Not a huge difference; the Hunter is nicely quiet here in my office. If the pollution cranks up, I just turn it up a notch and it’s still ok to talk easily.

  2. Just tried to buy the Hunter at Sundan SLT and they say they are out of stock and this model is out of production. The next one up was 3300 RMB. If you know of any place that still carries them or another reliable and inexpensive air cleaner please let us know. Many Thanks.

    1. So sorry to hear that! It was a great deal. Unfortunately, I don't see anything else at a level until ~3000RMB, as you say, such as the Blueair 302 and others. Perhaps people can still save money by ordering from the US and shipping over, maybe using dong-xi.com and it still may be the cheapest option, since many ok small-room models reviewed by Consumer Reports start around US$180-250. Units like the Honeywell 50250; the Hunter Permalife/Quietflo series; Whirlpool Whispure 510 have fair reviews. I always like to start my consumer product searches at Consumersearch.com; here's their review of air purifiers: http://www.consumersearch.com/air-purifiers

    1. Hopefully it's getting better and that I didn't just waste my money. I'm not sure how to 'benchmark' the purifier that I just bought though; that, and I can't really read the manual for specifications either. I just heard the sales rep mention HEPA and I just hoped for the best.

  3. I wish someone, somewhere could give a comprehensive review of the Yadu air purifiers, from their cheaper models to the top of the line. I've been tempted to buy one of the low-end models for my bedroom, but I'm guessing that it is only marginally effective at doing what it's supposed to. Seeing as they are relatively inexpensive, it would be great to know how they compare to reputable foreign brands. Is there really no one out there with some concrete figures?

  4. It’s a year on since your review – are you still happy with your Hunter? It seems to be back on the market (well, its showing online at least).

    1. I don’t use my Hunter much now — but I was very happy with the real-world data I got last year, and if it’s back on the market, great! Where did you see it sold?

  5. It’s on the Sundan website and Taobao. I haven’t actually attempted to buy though so can’t be sure they are in stock. Is there a reason you no longer use the Hunter?

    Have you come across any other good models in the cheaper price range? I’m on a tight budget so trying to decide whether to splurge it all on one higher end model or a couple of cheaper, possibly not as effective brands.

    1. I still like the Hunter — I’ve moved my office and am too lazy to get it out of storage! But it’s still a very good and quiet machine for small rooms, very affordable as well. As for cheaper models, I wish I could find one! I would love to borrow some Yadu models and check them out — but the good HEPA ones are still at least 3,000-4,000RMB

      I would definitely NOT go cheap on air purifiers, sorry! You get what you pay for, especially in China…

  6. I just arrived in China, and am considering buying this model from the link LauraC posted above. Is there any risk of this being a counterfeit product? I’m not very familiar with Taobao sales, and it’s a little weird that this product was discontinued over a year ago, but is still available there.

    Alternatively, Amazon.cn also has some reasonably-priced (under 2000 RMB) air purifiers manufactured by Sharp, Phillips, Panasonic, which seem like reputable brands to me. Some of them (like the Sharp KC-Y180SW) claim to use HEPA filters, so I suppose they’re at least somewhat effective?

    1. There’s always a risk of counterfeits on Taobao — but the price is about right, and the vendor has a good rating. that’s about the best I can say, sorry.

      As for other brands, I’m sure there are a few brands around $250-300 USD which are HEPA-rated and work well in small rooms. So yes, a 2000RMB model may be ok but it must be pure HEPA, working down to 99% filtration or higher. You should research model numbers on English sites such as consumersearch.com.

  7. I just bought a Phillips AC4074 HEPA filter and it seems a remarkable machine. At 5,000 rmb it is less than half the IQ Air 250 and they also have a smaller model, AC4002 for 3,000 rmb. For starters, these machines are much smaller and more beautiful than the IQ “washing machine” size and look. My friends comment “It’s so lovely.” It won a Reddot design award in 2008 and is very quiet. It also has an automatic mode that increases fan speed if room is dirty but it shuts off if room is clean (it has a built in air quality monitor) to save energy. It also has 4 speed modes and a silent mode for night time that is indeed silent, but seems to still move a decent quantity of air. It claims it can handle 270 square meters and that it filters 70% of particles down to 20 nano-meters. While some brands claim a higher percent filtration, that number is most relevant if you have a very large apartment or a leaky one. If you’re trying to just do a bedroom or office the lower percentage is OK because after 5 or more passes through you get down to some pretty clean numbers (0.3 x 0.3 x 0.3 x 0.3 x 0.3 = 0.0024, or 0.24% of the particulate left). This means that 70% filtration rate gets out 99.76% of the particles after 5 passes, more after continued passes so the fixation on the rate alone is mainly relevant for large spaces where you might only get a few passes.

    Many of my patients are concerned about how to address the air pollution problem, but fret about the expense. These two Phillips machines seem like a good option and I just bought mine at Suning appliance store.

    I found your referenced US Children’s Health Study out of USC rather sobering and indeed a number of schools are now considering modifying their physical education and after school sports schedules in response to air pollution reports. That study was done around Los Angeles and we probably average at least 4 times those levels of air pollution. Key point is that some of the damage to lungs may be irreversible. I recently had a patient who grew up in the LA area when it was dirtier and was diagnosed as asthma at age 35 (so had no idea that damage was accruing prior) and in my office had moderately diminished lung function (as measured by PEFR, Peak Expiratory Flow Rate) despite good asthma medications.

    Your website is a very great repository of health related information and conclusions and I love the links to the original papers if you want to read more. I often refer patients to your website for further reading. Keep up the good work. I think that you are right on the mark in your conclusions on the various topics discussed.

    Re costs, what are your lungs worth?

    Dr. Steve Misch

    Parkwayhealth, Chengdu, Shanghai

    Board Certified American Family Physician

    1. Thanks, Steve for your kind words for my blog. It’s especially nice for a family medicine colleague living and working in China to praise the effort I’ve put into this blog! I’ve always enjoyed spreading such information to the community.
      I’m glad you like this Philips option. Price is indeed an issue here. That’s still quite a lot for many people, which is unfortunate. Everyone should keep an eye on websites for sales by people moving away from China. In Beijing, we find some Yahoo groups like Beijingcafe invaluable, as well as posts on the Beijinger and other magazine sites.
      —- On Wed, 28 Nov 2012 13:22:28 +0800 Disqus<[email protected]> wrote —-

      NOTE: This comment is waiting for your approval. It is not yet published on your site. ======

    2. Thanks, Steve for your kind words for my blog. It’s especially nice for a family medicine colleague living and working in China to praise the effort I’ve put into this blog! I’ve always enjoyed spreading such information to the community.
      I’m glad you like this Philips option. Price is indeed an issue here. That’s still quite a lot for many people, which is unfortunate. Everyone should keep an eye on websites for sales by people moving away from China. In Beijing, we find some Yahoo groups like Beijingcafe invaluable, as well as posts on the Beijinger and other magazine sites.
      —- On Wed, 28 Nov 2012 13:22:28 +0800 Disqus<[email protected]> wrote —-

      NOTE: This comment is waiting for your approval. It is not yet published on your site. ======

  8. Hi Dr. Cyr,

    I was wondering if you are by any chance familiar with Philips’ AC4072, AC4074 and AC4076 air purifiers and the difference in their productiveness and maintenance?

    Thanks,
    Tal

  9. You mention “do not use the ionizer setting, it’s not considered healthy anymore by most reviewers.” To exactly what health risk were you referring to? I’m going to assume you were amusing to the dangers of inhaling large concentrations of ozone. If that was your concern, this technical issue has long been solved with the use of an inline catalyzer in the path of the air stream. A company my dad works with, Englehard, makes the majority of the catalyzer modules for home air purifiers. Ionization does a great job of killing bacteria and deactivating viruses. Most modern purifiers should come with the catalyzer pre-installed, so people shouldn’t have to fear using that feature.

  10. You mention “do not use the ionizer setting, it’s not considered healthy anymore by most reviewers.” To exactly what health risk were you referring to? I’m going to assume you were amusing to the dangers of inhaling large concentrations of ozone. If that was your concern, this technical issue has long been solved with the use of an inline catalyzer in the path of the air stream. A company my dad works with, Englehard, makes the majority of the catalyzer modules for home air purifiers. Ionization does a great job of killing bacteria and deactivating viruses. Most modern purifiers should come with the catalyzer pre-installed, so people shouldn’t have to fear using that feature.

  11. For a 50 square meter studio a blueair 503 seems to be a good choice and a bit more affordable when comparing on US Amazon. Where in Beijing would I purchase one and the smokestop filters bearing in mind limited mandarin.

    1. Blueair’s website is always the best option for dealers. A lot of expats use the Torana chain of stores…

  12. I use the Philips 4076 and two 4025s in the bedrooms… I can smell and feel the difference.
    I bought all on Taoboa … Using them over a year with the big one in the living dining room on full and the other two smaller ones in the bedroom.
    Walking out of my apartment into the elevator area I smell the difference. In one year I replace the filters every 6 monthes as recommended by the warning lights. I can easily get filters with next day delivery on Taoboa ….

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