Grad Student Rigs Cheap Alternative to Rival $1,000 Air Purifiers in Smog-Choked China


During the winter of 2012-13, air pollution in Beijing was so bad scientists likened it to a nuclear winter. Thousands of people checked into hospitals with respiratory diseases caused by a thick, choking fog.

The air has been so bad in Beijing that the U.S. Embassy issues hourly air quality updates on a special Twitter feed.

During the so-called “airpocalypse,” University of Virginia graduate student Thomas Talhelm was living in the Chinese capital on a Fulbright Scholarship. He was doing cultural psychology research that culminated in a “rice theory” study explaining north-south cultural differences that was ultimately published in the journal Science in May.

He also became one of the millions to suffer from the sometimes-lethal air pollution, the result of massive coal burning during a cold snap and China’s growing love affair with motor vehicles. Beijing alone has more than 1 million cars on the road.

Grad Student Rigs Cheap Alternative to Rival $1,000 Air Purifiers in Smog Choked China“I had to use a mask when I biked,” Talhelm said during a recent phone call from Beijing, where he has returned to do follow-up work on his rice theory paper. “I felt like I had asthma and it hurt to breathe deeply.”

Those who could afford it were resorting to an expensive solution: air filters costing up to $1,000. Because he was only going to be in Beijing for eight months, Talhelm was unwilling to lay out that kind of cash. “I thought it was pretty ridiculous. And on top of the sticker price, they really stick you for the replacement filters,” Talhelm said. “I could have afforded it, but if you are gouging me, it’s unfair. And there are plenty of people who cannot afford it.”

His solution was remarkably simple and really cheap. He strapped a HEPA filter to a fan and quickly began to enjoy clean air. A particle counter he purchased confirmed the filter was effective.

Talhelm published the results and began offering “Smart Air” workshops for people who wanted to make their own air purifiers. (He held one last week at U.Va.’s office in Shanghai.)

The workshops “mostly started as an expat thing,” but more locals are coming, he said. “I really enjoy the workshops.” During the 30-minute sessions, Talhelm presents data to support the efficacy of the filters and demonstrates how to build them. “I don’t ask people to believe me because I’m wearing a lab coat. People find that to be refreshing in China,” where transparency can be lacking.

Talhelm says the goal is not to make money and the cost of the workshops only covers materials, which cost about $33 per purifier. “I’m not putting money in my pockets – I’m paying employees,” six of whom work at Smart Air. “It’s like a social enterprise.” he said.

Smart Air is working with an engineering firm to help manufacture the air purifiers from the ground up, while continuing to keep the price down. “Once we have a product in place, our goal is to expand to India, Malaysia and Indonesia,” Talhelm said. The kits currently offered have found homes in the United States, England, Hong Kong, and Singapore.

So what do the high-end purification makers think of Smart Air? “My best guess is they have probably chosen to ignore us, that paying attention would legitimize what we are doing. I think I would ignore us, too.”




Grad Student Rigs Cheap Alternative to Rival $1,000 Air Purifiers in Smog Choked China

6 Responses to Grad Student Rigs Cheap Alternative to Rival $1,000 Air Purifiers in Smog-Choked China

  1. Bilter August 1, 2014 at 12:09 am #

    This is like fighting climate change with air conditioners.
    (Increase power demands with air filters, hell yeah.)

  2. Markoff July 31, 2014 at 5:40 pm #

    this article just it’s not truth, I live in China and I am familiar with Chinese prices and official air filter (with better design, but doing same thing as what this guy provides for public) start at 140-200USD range, far away from 1000USD BS mentioned in headline

    so yes, you can build it on your own for 1/5th of price but it will be more noisy and unprofessional looking, basically same as with any other product

    and btw. this was news like 1 year ago or even more

  3. Joe B. July 31, 2014 at 2:34 pm #

    China needs to enact emissions controls (vehicle and industry emissions checks) enforcement now, not air purifiers. This just addresses a symptom of a problem when the air is contanminated with particles AND gases, the gases (NOx, COx) will not be filtered out by HEPA filters that only trap particles. It’s much better to clean up the sources of pollution, and go from thick yellow smog to just haze.

  4. Chris K July 31, 2014 at 12:25 pm #

    Whats even more sad is that those $50 airfilters you can buy on amazon in the USA are all made in china, yet they charge their own people $1000 for essentially the same product.

  5. Clint July 31, 2014 at 11:24 am #

    I built nearly the same thing with a box fan and two square filters about a decade ago. Duct-tape the filters together in a triangle in front of the fan and seal the top and bottom with cardboard. This gives more surface area and so is quieter. $30-40.

    I have used this when sanding drywall, etc., when dust was a problem.

    For my time in China, it was the kerosene-like stench coming off the coke batteries that was the real problem. China has no EPA, thus no filtering – think Dante. Anyway, I used an electrostatic filter then to great effect, it cost $179 from Sears.

    The thing I credit this guy with is getting the word out. I never realized the answer wasn’t obvious.

  6. Mike Perry July 31, 2014 at 10:00 am #

    Much ado over nothing This sort of thing has been around for a long time. In the U.S. they sell devices that do precisely this. Search Amazon for ‘air filter” and you’ll see lots of examples, some under $50.

    The design is just like this. Fans pull in air, passing it through a HEPA filter. You can typically pick them up at Goodwill for about $10, although the filters are still pricey. I used them when I lived in Seattle.

    Were I building one, I’d put a regular, cheap-as-I-could-find air filter in front of that HEPA, so it doesn’t need to be replaced as often.

    –Michael W. Perry, Across Asia on a Bicycle

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