Car air purifiers sound like a great idea. Soon after I started making DIYs, people emailed me asking if we could make a DIY for their car. My initial reaction was, “Great idea!” On the highways, we’re surrounded by all of that awful pollution. Best to get a car air purifier. … Read more
Air purifiers work best in a closed room environment and this worries some who are concerned that there wouldn’t be enough oxygen coming in when all doors and windows are closed. Yet recent tests in a real apartment — with as many as seven people in a small room — show less … Read more
Tests show that keeping the doors and windows closed will keep particulate levels at 50% less than outdoor air on average. But some people really want to keep their windows open. For some people, it’s an old wive’s tale that windows must be kept open. For others, it’s a way to … Read more
When buying a purifier, you’ll sometimes see companies use the word “airflow” (风量) to describe an air purifier’s performance and other companies the word CADR (clean air delivery rate) as seen in the picture below. They’re both a measure of purifier performance, but are they the same thing? … Read more
When I started Smart Air, a lot of people asked me how long the HEPAs last. Several people criticized the DIY on Zhihu because they said you’d probably have to change the HEPA so often that it’d end up being more expensive than the expensive brands. At the time, I really wanted to … Read more
We know that air pollution is bad for our health, it causes heart attacks, strokes and lung cancer. But how about the more day to day impacts of air pollution? Feeling tired, drowsy or does going to the office make you sick? The data shows that poor indoor air quality is … Read more
The World Health Organization tallied up all the deaths due to outdoor air pollution based on different causes, and the major killer isn’t what most people think. Asthma, lung cancer, and emphysema come to mind when we think about air pollution. But lung problems are only a small portion of the … Read more
The other day, someone on Quora asked whether ionizers actually purify the air. This is an important question because ionizer purifiers are all over the place. For example, I was at a friend’s apartment in the US, and I saw his tower fan had an ionizer button on it: It’s … Read more
HEPA filters are a nearly perfect solution for air pollution. They are backed by tons of scientific tests; they’re pretty cheap; they use about as much energy as a lightbulb; they even have documented health benefits. Just about the only remaining problem is that you have to throw out the HEPA filters every … Read more
After I tested every fan in China I could find with a flat front… …the results of one fan stood out above the rest. Because of its appearance and how much butt it kicked, I called it “the Cannon.” In Anna’s 15m2 Beijing bedroom, it crushed particulates. It removed 97% of … Read more
