UPDATE, March 2015: Please check out my buyer’s guide to air purifiers; my 2014 review of the science behind air purifiers; my 2015 tests of air purifiers under 1,000 RMB plus my 2014 review of two dozen top air purifier models in China.
Beijing’s internet forums are always filled with heated debates as to which air purifier is best: IQAir vs Blueair vs others; import vs local; etc etc. I finally decided to jump into the fray and enter the great debate. As I’ve mentioned in many posts, I am a big fan of indoor air purifiers because I think indoor air pollution is a serious public health concern here in China. And while indoor plants can help a lot, I think the machines are far more effective. So, which machine should you buy — if any?
I personally use three brands; in my small office I have a Hunter 31125, which is a true-HEPA filter. It’s Taiwan-made from the American company Hunter, and I bought it for around 1248RMB at the Sundan electronics store at the Sanlitun Village mall basement. At home, we have two machines which are also HEPA filters; the bedroom has the Blueair 501 which we bought for around 6,000RMB, and the living room has an IQAir 250, which I believe was around 11,000RMB.
Real World Tests: Blueair 501 vs IQAir 250
Last year I borrowed an air particle monitor from IQAir and did a lot of spot checks at home to check out which purifier at home — my IQAir or Blueair — worked best. My den (living room) is about 40+ square meters, and my bedroom is ~20 square meters. Both of my machines’ filters were a couple months old. The original data is in the table below (note that “%” means “percent of that room air versus current outdoor air”).
You can parse (spin?) the data many ways, but here are my conclusions:
- Normal settings: with the typical mid-level speeds, I didn’t see much of a difference. Both took out 60-80% of the particulates.
- Max settings: Again, I found no major difference. Both removed 80-90% of particulates.
- On the worst days with AQI over 500 (!), I still couldn’t get any room under the more desirable 100,000. Scary, no?
- Rooms are different: my bedroom consistently had better air than the den (good news for me)
- Without any air purifiers, the indoor air was 72% of outdoor air
My Hunter Did Very Well
My smaller air purifier, the Hunter 31125 in my small office, also did quite well. It routinely got 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. I think this is a great option for small rooms, and at 1290RMB is far cheaper and smaller than the other brands.
Real World Reviews: Survey Says…
Readers should definitely read the most objective sources out there and try to avoid the many “review” sites which are essentially shills for selling particular brands. One reputable consumer group, which is free, is the Consumer Search group. In their reviews of air purifiers, they list:
- Best Air Purifier Overall: IQAir HealthPro Plus
- Best Value: Austin Air HealthMate
- Best For Small Rooms: Honeywell Enviracaire
This website has a ton of good info and links to the most reputable reviews, so readers should definitely use this website. The magazine Consumer Reports also has an excellent reputation for reviews; interested people would need to pay online to download their review of air purifiers, but a tiny one-month charge is nothing compared to the thousands you may spend on machines, and their advice is highly regarded.
What About Local Products?
I would love to endorse a locally made brand such as one from China’s reputable brand Yadu, but I’m simply not aware of any good research, at least available in English. If anyone has such information, please share with readers in the comments section below.
The Bottom Line: It’s All A Cost-Benefit Analysis
So here you are with all this information, and you need to decide. The biggest factors are quality and cost. Buying imported seems to be a no-brainer, at least for now. In my real-world tests, I didn’t see much difference at all between Blueair and IQAir. IQAir does have many good reviews out there but the price difference is a serious issue for many; it’s less of an issue if you plan to resell, since the resale value is high. I think the next level under these two brands are the highly regarded but less locally available models from AlenAir, Austin Air, and Honeywell. I’ve read on the Beijing blogs that some are happy with Alen Air, which has an easy website in English and ships for free from Hong Kong. (I think World Health Store just started to carry Alen Air?)
Don’t Get Ozone Ionizers
Last but not least; do not buy ozone-creating purifiers that ionize the air. This was trendy a few years ago, but there is now excellent data that ozone itself is an indoor hazard. No reputable company or reviewing magazine recommends ozone-creating ionizer machines anymore.
Air Pollution Info-junkies, Here’s Your Fix
I created a full page listing my top pollution articles here.