The Smartest Air Filter In China

I've been living in Beijing, China since last August. Whenever I talk to friends in other countries, the subject of air pollution comes up. Is it really as bad as the international media makes it out to be?

Yes and no.

Sometimes we get blue skies in Beijing, especially after a day of strong wind or rain clears the smoggy air. But then the pollution builds. If we go more than ten days without much wind or rain, the pollution can reach horrendous levels.

The typical metric used to measure air pollution is the PM2.5 count. This measures the concentration of particles that are 2.5 micrometers in diameter. A PM2.5 count below 50 is considered healthy. As I write this, Los Angeles is at 60 (moderate, few people will be affected).

Late last year, the PM2.5 count in Beijing reached 500.

Some friends and I rode across the city in a taxi that night. Visibility was so low, I felt like I was in Grand Theft Auto, and the background wasn't rendering properly. Or maybe “pea soup fog” is a better analogy. Either way, it was quite scary. Buildings, cars and people seemed to appear out of nowhere. I was worried there would be a traffic jam (a common occurrence in the city), and our driver wouldn't see it until it was too late.

Luckily, it rarely gets that bad. Typically, the level is high, but tolerable. And we usually get at least one blue sky day every week.

One thing I've learned since moving here is that everyone who can afford an air filter has one. The name brand filters are about twice the size of a desktop computer tower (remember those?), with blinking lights and other bells and whistles. They tend to cost upwards of $1000, with some models costing far more. Katie and I almost bought one right away, with the thought that you couldn't put a price on our health. But then I heard about Smart Air, a new company that aims to make air filters available to the masses. The concept is simple: buy a desktop fan and Velcro a HEPA filter to the front. Smart Air sells their fan/filter combos for $33. Replacement filters are $14. They ain't pretty, but the price is right.

I bought their DIY kit and set it up. After running the fan for a day, I was astonished. A dark circle had already formed on the front of it. After two months, I changed the filter. Here are the “before and after” photos:

Of course this isn't scientific, but it sure looks like the filter did its job. It's scary to think of the amount of soot that would have ended up in my lungs had I not been using a filter.

Smart Air has some more extensive empirical data on their website. They even compare their filters with the most popular brands. The most expensive filters did perform slightly better than the HEPA filters that Smart Air sells, but at a significant cost.

I've become a big fan of my Smart Air fan. I plan to continue using it as long as I'm in Beijing. What do you think?

External Websites:
Smart Air
More info about PM2.5 from the EPA
Current pollution levels