Which is the best air purifier for China? I get asked this question all the time, and my articles discussing my own test results still are the most popular articles on my website (here, here and here). But I’m just one data point and can’t try all the models available. For objective tests, I’ve always been telling people to read the independent Consumer Reports test results, as well as the reviews from Consumer Search. But finally we have new data points specific to the machines available here in China. Mentioned in Shanghai Daily, they report on the Shanghai Consumer Rights Protection Commission’s new analysis of 22 air purifier models. They focus on PM2.5 and formaldehyde, arguably the two most serious indoor air pollutants on our health. Quite a few brands didn’t do so well! Anyway, the original article is in Chinese but I’ve Google Translated the table below. How did your model do? I’m happy as my home’s Blueair did great, removing 97-99% of both formaldehyde and PM2.5;

I don’t see results for my IQAir here. But there are many others: Panasonic, Daikin, Sharp, Yadu, Honeywell…The Chinese smartphone startup Xiaomi is being assaulted from all angles. Analysts are questioning the company’s $45 billion valuation; CEO Lei Jun must defend his smartphones sales target; and the press is questioning the quality of its product—not even the foreign press, China’s own media. This week, a story appeared on the People’s Daily website, the top mouthpiece of the Communist Party, Xiaomi’s air purifier was producing believable results. The reporters were tipped off by posters on Chinese social media who complained that their new purifiers, which include a HEPA-filter packaged in plastic, were producing results with the wrapping still on. “It’s still running at full speed without removing the filter cover and its app display level decreased significantly,” the story said, referring to the smartphone app that pairs with the filter to show real time changes in air quality.

“Therefore, there’s a suspicion of fraudulent data.” The story bounced around Chinese media this week. It ran under an official Xinhua news agency byline on Tencent’s WeChat, and appeared on popular tech hubs like Sina news. The CEO of the Xiaomi subsidiary making the device, Zhimi Technology’s Su Jun, tried to explain the misreadings, or misunderstandings, in a Weibo post, China’s Twitter equivalent. But the company deleted it soon after, explaining that it was too complicated. A Xiaomi spokeswoman declined to comment about the stories. Zhimi posted a certification from Chinese testing agencies testifying the quality of its air filter on Sunday. The post was , ‘We let the reports and data to speak for themselves.’ It ended with a nonchalant smiley-face emoji wearing sunglasses, smoking a cigar. That may be the best tact to take with gripers on social media. The Xiaomi air filters reviews online. Immediately 800,000 units were sold when it launched earlier this year.

In China today, most consumers are skeptical about products, especially Chinese-made ones, that carry health claims because of a recent history filled with . The air filter skepticism may be a symptom of that mistrust. What’s worth following in the Xiaomi story, should more criticism surface, is how closely the state media follows the reports. air purifier retailersThat’s one thing the Chinese haven’t come to expect. small plug in air purifierWritten Upvoted by Kaiser Kuo, There's no such thing as a "budget" air purifier in China, as the markups here are much more than you'd pay in the USA, for example. pure ion air cleanerThe cheapest setup often is an installed HEPA filter inside your heating and AC ducts. But for most people, a portable unit in each room is the more convenient option.

There are many models here in China; website, which collects reviews from all major sources. There was also a very helpful testing done in Shanghai in 2013, they tested over 2 dozen models for formaldehyde and PM2.5. Their results also include prices. I translated their post into English here: Finally, Great Data on Air Purifiers in China!Written Hey John, thanks for the shout out! I've been doing research on how filters work and using a particle counter to test the effectiveness of a DIY design. I've come up with a 200 RMB model (tests below), and I'm coming out with an even stronger model soon that will be between 400-500 RMB. I post all of my data and tests online, so you can judge for yourself: 1. Live test of the filter2. Tests showing the original DIY filter gets an average of 84% of particles larger than .5 microns and 92% of particles larger than 2.5 microns3. Tests of a newer, stronger model that gets 96% of both!Instructions on how to make one are on the Tumblr. However, several people told me they were having trouble finding the parts, so I've started ordering in bulk and shipping from Smart Air.

Clean air really shouldn't cost $1,000.Written When you use the term a budget air purifier are you referring to an air purifier which is cheap just based on the initial price you pay for buying it? Then there are many out there but I'd suggest you factor in both the operating cost (most large air purifiers consume a lot of power) and the maintenance cost (most air purifiers need a filter change every 2-3 months) and then make a wise choice. For instance I use this small yet effective room Air Purifier which fits my bill. You can look for similar ones.Updated Here's a tumblr of a guy who seems pretty serious about finding a budget air purifier, and maybe has done so.  166 RMB or so: Particle Counting  Edit: formattingOne of the most frequent questions I get asked is “What kind of air filter should I get?”  This is great to hear because it means that people recognize the need for clean air and are trying to do something about it!  Also, in China, the level of air particulates indoor is quite high and we regularly see clients test at levels that are as high as 15x that of the EPA annual standard (15 micrograms/ cu. meter of air).  

There are multiple solutions to high particulates, but oftentimes, clients want to achieve cleaner air without a lot of change in their daily habits.  (ie. washing your cat). Or, if you close your windows to the outside air, you can cut down your particulates but at the cost of less ventilation, which can generate stuffier air and higher levels of other indoor pollutants. Air filters (sometimes called air purifiers) are a good way to both make a big dent in particulate levels, and some can also reduce odors or toxic gases. For options we have, please check our online store. Unfortunately,  it’s pretty confusing, especially when you are trying to do your homework and have each brand salesguy telling you a different thing.  There are also a lot of different technologies out there, many of them proprietary and unfortunately, gimmicky. Since I test air for a living, I’ve had the chance to evaluate what’s out there, play with the units, and spend time with the product reps.  

Today, I had a call with a client who is very conscientious about her health and is doing all the right things, but still had a high particulate (PM2.5) count and wanted to know what she could do.  There are a few general points I shared with her that I’ve replicated here: 1. Get the filter that is right for your situation or problem. For instance, someone who has recently renovated and has high levels of formaldehyde needs a different purifier (something with a gas filter, usually activated carbon) than someone who has allergies or asthma (HEPA filter capable of filtering the smaller particles likely to trigger allergic reactions) than someone who has a compromised immune system (special type of HEPA filter capable of ultrafine filtration plus UV-light to kill bacteria or viruses). The big differences are particulates, odor/gas removal, and ability to kill microbes. Like everything else in life, trying to get one that does everything well will either cost you a lot or sacrifice performance somewhere else.

Spending some money to test your air first can help you identify what to get and save you from overspending on a filter you may not need.  Here’s a primer on what are the most common pollutants in Shanghai, their sources, and health effects. 2. Look for HEPA (high efficiency particulate absorbing) filters. It’s a dirty secret, but all true HEPA filters will filter 99%+ of particles sized 0.3 microns or larger. A filter cannot be called HEPA unless it meets this industry standard. For reference, a human hair is about 40 microns thick and your body (if healthy) does a pretty good job of naturally removing particles 10 microns or larger. The smaller, the worse it is for you because the smallest particles bypass the body’s nasal hairs and mucous (yes, the Beijing hack does serve a purpose!) and penetrates deep into the upper lungs and into the bloodstream.  There’s a pretty complete guide for particle  sizes, but strangely, they don’t list one of the most common allergens  – can and dog dander.  

(for the record, around 2 microns) Avoid things that sounds like “HEPA-like” or “partial HEPA”. “True” HEPA is ok. The finer the filtration, the better, right? The finer the filter, the harder the machine must work to push the air through the filter — the only way it can do this is to either have a stronger motor (louder) or wear out the filter faster. Just get enough for what you need and don’t get swayed by one manufacturer that says they can filter 99.97% vs. their competitor who “only” filters 99.3%! 3. That said, all HEPA machines are not built the same. The capability to circulate the air is very important. The larger the room or living space you’re trying to purify, the more important this is. Generally, this is where the larger, more expensive machines shine. IQ Air, Blueair, Alen, are the biggies in Shanghai and all of them do a good job of ensuring that all of the air in the dimensions their machines are rated for are clean. Ask to see the manual to understand the number of air changes they can do every hour as a common metric.

However, this is only useful if you understand what efficiency the air is being cleaned at. If you only need to clean a single room (ie bedroom when sleeping), you can do well on a limited budget with a small HEPA purifier. Or, you can drag it around with you wherever you go on a long extension cord (not a joke — one of our clients does this). 4.  Avoid purifiers that produce ozone.  Ozone is a gas that is extremely reactive and forms byproduct gases on contact with organic material.  In the atmosphere,  it protects us from UV and in water, it is used to disinfect.  But, if you breathe it in, it is very damaging to the body, causing coughs, chest discomfort and eye, nose, and throat irritation.  It can also aggravate asthma by increasing sensitivity to allergens and cause long-term scarring of lung tissue.  There is a 30% higher incidence of lung disease in cities with high ozone.  A few machines produce ozone to attract particles which drop to a collection tray or worse, emit ozone.  

Remember the Sharper Image’s Ionic Breeze machine?  Shows you what millions in marketing dollars can do when an air purifier creates more unhealthy air than you had to begin with.  Most retailers and manufacturers avoid ozone like the kiss of death, but this is China and you never know, so check the fine print.You’ll be trying to sleep while it’s running. Manufacturers have a decibel rating, but this is not very useful — I’ve seen some of Blueair’s machines’ rating to be inexplicably high when the sound is actually much lower in practice. Go and test out the machines before you buy on all speeds. Better yet, listen to it in someone’s house instead of a noisy salesroom floor. 6. Cost of filter replacement. This is a biggie. Think total cost of ownership over time for the filter you need. Alen and Blueair are quite similar, at about 500-700rmb / 6 months. Filters with gas removal capability usually cost more because they add carbon to the mix.  IQ Air is about twice that.

There are some interesting models by Sharp (Plasmacluster) that can be washed (including the carbon odor/gas filter), which means you actually don’t need to replace the filter for 5 years. However, I haven’t seen how efficient these are over time.  Models that have a precleaner that can be vacuumed may extend the life of your HEPA filter.  Most importantly, change your filters according to the recommended guidelines!  A 1000rmb HEPA Yadu purifier with a new filter will clean your air better than a 15000rmb IQ Air Health Pro Plus with an old filter, hands down. 7. Why not just buy a unit from the US (usually cheaper there than in Europe) and bring it here? Assuming you don’t want to use up that luggage allowance bringing over salami, nice hard cheeses, or 20 iPads to sell here, there is a matter of voltage. US machines will be 110V, requiring a transformer here and if you run the machine 24/7, the transformer will waste a lot of energy being constantly on. Even if that didn’t bother you, there’s a reason that the manufacturers don’t recommend this.

The cycle is different. US are on 60 cycles, China is on 50. Transformers change the voltage but not cycles, meaning that the motors run at a different speed than designed, causing all kinds of mechanical weirdness and potentially different filtration results. I am not sure if this voids the warranty, but it wouldn’t surprise me. Just don’t do it. 8. Don’t undervalue after sales service. The three brands I mentioned before all have local product experts who will support you, answer your questions, differentiate between models, and continue to provide filters and warranty service after the sale. They also will be able to answer your questions halfway intelligently as opposed to the brand sales clowns in Gome or Suning who will look at you like you’ve got a pecker growing out your head if you start asking these questions. When I first came to China (before getting into the testing industry) I bought a big Yadu and Malata, another local brand. A year later, when it was time (overdue actually) to replace the filter, the retailer no longer carried the model at all, and when I got a factory number from them, the factory didn’t have the filters anymore.