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.
In my seven years here in China, one of my most annoying chores has been researching air purifiers for my house — and maintaining them. It’s just exhausting to research brands, figure out what rooms need which — and of course calculate what’s the best value. It’s also an endlessly annoying hassle to keep searching for the cheapest replacement filters, which are far more expensive here than in the USA. I hated feeling helpless to rely on sales pitches from just a couple of companies, so I started to do my own home testing and posting on this blog. This summer I tested a new entry to China, the Airgle series (Chinese website here). I pitted their PM2.5 flagship model, the PurePal Clean Room Air AG900, against my steadfast friends IQAir and Blueair. Which came out on top this time? Here’s my report.
The Prep Work
First, I needed a handheld machine to measure the pollution. This time, I borrowed a model called Chinaway from the team at Vogmask. This calculates the PM2.5 and PM10 concentration directly, in ug/m3. To convert this to the more familiar AQI, you need to use the online concentration-to-AQI calculator here, from the US EPA.
Next, I borrowed the Airgle from the local vendor (started by Charlie Thomson, our local Aquasana rep). According to their website, it “features a 40 sq ft cHEPA filter with an efficiency of over 99.991%”. I then spent two weeks comparing this to my home’s five (!) machines: two IQAir Health Pro 250 models, one IQAir Health Pro 150, one Blueair 501 and a Blueair 403. I rotated all of them through four different rooms: my kitchen, the living room, and two bedrooms. Then I recorded the PM2.5 a couple of times each day and entered all the data into a gloriously complicated and colorful Excel spreadsheet. Since I didn’t have a “test room” this time, I compared each room’s PM2.5 with the outdoor air at that same time (outside my window).
The Main Conclusions
1. General protection was good with all: Wouldn’t it be wonderful to eliminate 80% of your lifetime exposure to China’s pollution, at all times? How about 90% or better when you’re sleeping, which is one third of your life? I think that’s a pretty darn good goal — and my tests showed overall efficiency of 84% using all models together, which I feel is extremely reassuring. While the outside PM2.5 averaged an unhealthy 84 ug/m3 (AQI of 166), my indoor PM2.5 was a much better 13 ug/m3 (AQI 53). Think about that — my newborn child, since he’s almost exclusively at home, has a sharply reduced exposure to China’s air pollution during his entire childhood here in China, thanks to air purifiers.
Here’s the overall efficiency for each model:
- Larger models: Airgle AG900: 85%; IQAir 250 #1: 78%; IQAir 250 #2: 79%; Blueair 501: 81%
- Smaller models: IQAir 150: 83%; Blueair 403: 80%
As you can see, all the larger models were about equal effectiveness, getting 78-85%. The Airgle did the best, but given the homemade statistics of my sampling, it’s difficult to state if this is truly a better machine. But in either case, it worked at least as well as the other models.
2. Bedroom Results: As I’ve mentioned in previous results, you can instantly eliminate one third of your lifetime exposure to China’s pollution simply by using a good purifier in your bedroom and closing the doors while sleeping. All models were on their quieter settings, providing a nice white noise in the background which I actually like. Here are my results this time:
- Master bedroom: doors closed overnight 90%; total average 84%
- Small bedroom: doors closed overnight 88%; total average 89%
I mostly worry about protecting my six month old son, so I am pleased that his bedroom was 90% protected at all times. Some morning readings approached 99%! But you certainly don’t need the flagship models in a small bedroom: the smaller models were perfectly fine.
3. Large room results: My open kitchen, dining room and living room are all connected, so it’s been difficult in the past to properly filter these rooms. I recently added a second IQAir 250 to join its older sister in the front, and I am very pleased that my results prove that I finally have good coverage, hitting that 80% goal for the first time in my three tests over the years. The further good news is that all combinations of the larger machines did well. The Airgle also did very well, and is much quieter than the Blueair 501 at the maximum speeds. Here’s the data:
- Living room average: 85%
- Kitchen average: 82%
Sometimes the PM2.5 levels shot up, especially with Chinese cooking (also candles and incense!) and cranking them all up would bring levels down. But at max settings, I’d have to give Airgle kudos for having the quietest volume at max speed.
My Bottom Line
Clearly the filtering technology in the Airgle and the IQAir are superior to the Blueair, as they both have closed HEPA filters which literally filter essentially 100% of particles even smaller than PM2.5. Both models got a very impressive PM2.5 reading of zero (100% efficiency) when I held the monitor right at their outflow of filtered air. But as my results show, it’s not just about the HEPA filter, it’s also about air flow rates and CADR results. Blueair was a solid performer in my tests even with their lower-CADR Smokestop filters — which weren’t even brand new, by the way (8 months old). But I’m sure you can argue that a better HEPA filter is preferred for China’s harsh environment, as there are plenty of other pollutants and VOCs which may be much better handled with a better filter.
Actually, one could argue about a lot of variables with these machines, especially value. And the prices of both Airgle and IQAir models in China right now are super expensive, and there’s just no way I will be convinced that it’s all about taxes and shipping extras. Sure, every commercial product has premium brands, but the markups boggle the mind. The Airgle models sold in China are made in China, and they are far more expensive here than the ones in the USA — which are exported from their South Korea factory! The Airgle AG900 in the USA is only 5,518 RMB ($900) on Amazon, a small fraction of the 17,990 RMB price here in China on their Taobao store. I personally think there’s a lot of pure corporate greed going on in this industry, taking advantage of Chinese consumers’ fear and demand. It may be legal, but it’s not ethical, and it really irks me that the world’s most vulnerable populations, much poorer and in far more polluted cities, are forced to spend far more to protect their health. It’s no wonder everyone’s reading about an American’s testing of a DIY air purifier for 166 RMB! I also recommend that consumers check out an excellent comparison from Shanghai of two dozen models, including prices and results from PM2.5 and formaldehyde.
But don’t get too bogged down on the sticker shock — in general, you do get what you pay for. And don’t forget to factor in the replacement filter costs, which can easily cost more than the original machine when stretched out over a 3-6 year window.
I am honestly very impressed with Airgle’s technology, style, solid build and quietness, but I already have a bunch of purifiers. If I had to start all over again, I think both the Airgle and the IQAir top models would be great for my large front rooms and kitchen. But right now my two IQAir 250’s are doing just fine — and the newest models are reportedly even more efficient and quieter, which would be nice. My IQAir 150 remains in little Alex’s bedroom, and the Blueair 501 quietly hums away in our bedroom. No matter how the wind howls outside, no matter what the next airpocalyse will bring, we sleep safe and sound.