Four years ago, I was coughing through a Beijing winter and wanted some clean air. But all the purifiers I could find cost hundreds of dollars, so I strapped a filter to a fan I had at home and made my first DIY purifier.

It wasn’t pretty, but I tested it with a laser particle counter, and the data showed it significantly reduced the particles in my bedroom air.

It worked, but it had some problems:

1. It’s loud. On high, it’s about as loud as major purifiers, but that’s still loud.
2. It’s kind of a hassle. You have to strap the filter on, and I’ve seen some people do it wrong.
3. The fan isn’t really made to power through a dense HEPA filter. A stronger fan would give a lot more clean air.

Fast forward 4 years and hundreds of tests later, I’ve got a new pair of machines that squashes those problems, and they’re badass. They’re my first non-DIY purifiers. Meet the Blast and the Blast Mini (or Ladakh and Ladakh Mini in India!).

OK, OK, the Blasts are pretty basic. It’s a metal box with a fan and a super fat HEPA filter inside. That’s not some kind of technological marvel. All purifiers are boxes with a fan and a filter inside, but the Blasts have a bigger fan and a much bigger HEPA. That means:

The Blast Mini puts out as much clean air as about 2.2 Blueair’s or IQAir’s.

But with that much air coming out, it’s gotta be noisy, right? This bad boy is actually quieter than a Blueair or IQ Air.

As always, I’ve been testing this under real apartments and publishing all the data and methods. But it’s kind of unfair because they clean so fast. Here’s the Blast in the 34 m² Smart Air office, and here’s a video of the test.

Throughout all this testing, several times I’ve asked, “Did anyone turn this on?” It’s that quiet. After experiencing it for a month, I bought up the first few to give to a few friends.

Your lie detector should be going off by now. How can it be more powerful and quieter? Well, for one, the HEPA is fat.

(area calculated taking the HEPA filter and opening all the folds)

That means the air can spread out over a large area. Imagine trying to blow really hard through a straw. Now imagine blowing air through a traffic cone. It’s a lot easier, and it’s quieter.

Second, this guy here Paddy engineered the fan and air duct, and he’s an aeronautical engineer. Really. He believes in his creation so much he even pretended to read a magazine next to it.

It also means he knows how air moves and designed the fans so that they work well and stay quiet.

So the Blasts are more powerful and quieter, well then they must be more expensive. Nope:

I calculated that the Blast Mini can easily clean up to 85 m². That’s good for most apartments or houses. And for big apartments or places like offices, gyms, and cafes, there’s the Blast which cleans up to 130m². And because the Blast’s HEPA is twice the size of the Blast Mini’s, it’s even quieter.

So, what makes the Blasts so special then? Not a whole lot, just in true Smart Air fashion I’ve packaged them without the high price tag and margin, and bundled them along with hundreds of hours of test data to verify they actually work.

My aim is still the same: make clean air more affordable, and get it out to more people.

As I write this, I want to apologize for feeling like I’m selling this thing. After four years of working on Smart Air, I still haven’t taken a penny for myself. I’ve got a day job (I’ve now moved from grad school life to professor life), so I use any leftovers to pay the Smart Air team an almost-livable wage, set up in India and Mongolia, and subsidize our educational workshops.

So I’m sounding a bit different from usual, but it’s because I’m excited. Four years after building my first DIY, the accumulated data is saying my initial hunch was right—it IS possible to get clean air for a heck of a lot less than what Blue Air and IQ Air say. Data sets us free!

P.S. I couldn’t help making a GIF.