When to change your HEPA filter can be a difficult question to answer. I’ve always questioned those numbers that air purifier companies give you. Where do those HEPA filter replacement numbers come from? If a company that’s based in Switzerland is telling you can use it for six months, is …
The Xiaomi Mi 2 air purifier – a good cheap and effective air purifier? Ever since I coughed through a Beijing airpocalypse, I’ve been saying clean air doesn’t need to cost an arm and a leg. I even set up Smart Air to provide low-cost purifiers to people around the …
Many purifier companies offer air purifier rental services as part of their business model. It sounds great: they offer to rent you an air purifier short term, and you save money in the process. This simple analysis will show why that system is flawed, and how renting air purifiers is …
There’s a lot of fuss around 0.3 micron particles. What’s a 0.3 micron filter? Why are HEPA filters listed as filtering 0.3 micron particles? Can masks and HEPA filters capture 0.3 micron particles? This article will provide the answers to these questions. What Does “PM” Mean? To understand what PM0.3 …
Should air purifiers have the filter on the front or the back–is it better to push or pull air? The Smart Air lab in Beijing ran tests of the same fan with the HEPA filter on either side, and the results contradict most people’s intuition. When I made my first …
