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 world based on that data. […]
Category: Reviews
Recent Reviews Articles:
Dyson Pure Cool Air Purifier Test: Shockingly Bad | Review
Dyson’s Pure Cool air purifier looks impressive. However a review of its clean air rating (CADR) reveals this filter does a poor job of providing clean air – the Dyson TP05 Pure Cool’s CADR comes in at just 164m3/hr. That means the Dyson Pure Cool air purifier out as much clean air as a $20 […]

How Long Does a HEPA Filter Last?
“How long does a HEPA Filter last?”. “How often should I replace my HEPA Filter”. These are two common questions I got asked when I started teaching people how to build air purifiers. Rather than just give people a nice-sounding answer, I wanted to see what the data says, so Smart Air co-founder Gus has […]

Can Masks Capture Coronavirus Particles?
With the outbreak of the coronavirus, many people are wondering if masks capture coronavirus particles. It’s a lot to ask billions of people around the world to become mask experts overnight. There is a lot of conflicting information. Do surgical masks capture coronavirus particles? Media outlets like US National Public Radio have claimed they don’t. Fortunately, […]

Are Japanese Pitta Masks Effective Against Air Pollution? Review
In recent months, the Japanese Pitta masks have seen a surge in popularity in Chinese cities like Beijing and Shanghai, as well as in India, the US and South Korea. They look sleek, but I wanted to review whether the Pitta masks actually work, and how effective is the Pitta Mask at filtering PM2.5, […]

Top Air Purifiers in Shanghai Consumer Protection Bureau Tests
Using actual air purifiers test data on is the best way to cut through the misleading marketing claims purifier companies make to try to get us to pay more money for clean air. For that reason, I’m always on the look out for good test data. Data is power. One source I like […]

Do Masks Really Work in India’s Air Pollution?
Every year when winter rolls around, a billion people in India are left breathing toxic, polluted air when on the streets. Be it in Delhi, Mumbai, Kolkata or Hyderabad, everyone is forced to become experts in a complicated scientific question to cope with the pollution: Do air pollution masks work? I’ve heard doubts from smart, […]

IQAir Atem Review – Is This Portable Air Purifier Effective?
The IQAir Atem is a personal, portable air purifier that’s new on the scene. Recently, air-breather Vincent asked Smart Air to review the IQAir Atem, which IQAir calls “the most effective personal air purifier.” IQAir Atem Review and Test Being the data nerds that we are, we decided to get some data to help us […]

Why You Should Never Use Your Air Purifier’s Auto Mode
Many air purifier companies add fancy features to help market their products. One of these features is an “auto mode”, also called “smart mode”. The idea behind smart purifiers’ auto mode is simple. The purifier has a small air quality monitor inside. When the air is bad, the purifier turns on. After the air […]

This Data Explains Why You Should Never Use Your Purifier’s Auto Mode – Supplemental Data
Data and Test Details Test Methods: These tests were identical to my previously published tests, details of which can befound here, here, and here. Original Data: The original data for all 13 tests is available as an Excel file here Average Outdoor PM2.5 During Tests It’s important to note the average outdoor PM2.5 during tests because purifiers achieve smaller percentage […]
