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 few months. So wouldn’t it […]
Author: Choon Khin
Choon Khin is a Smart Air engineer from Singapore, studying chemical engineering at the National University of Singapore
You thought rain washes away pollution?
I’ve wondered whether rain decreases pollution for a long time because I’ve noticed two things: 1. Sometimes after it rains in Beijing, the sky is gloriously blue. When that happens, many people like me say, “Wow, the rain really washed away the pollution!” 2. But then sometimes it rains and rains, and the sky still […]
Smart Air Indoor Air Quality Audit in 3ESpace
Date of audit: 27/05/2017 Audit conducted by: Yap Choon Khin Paddy Robertson Air quality monitor: Dyloc DC1700 Pro AirVisual Node Audit location: 3ESPACE, Beijing Jiaodaokou, Xinhua New Culture Building, 5th floor Air quality measurement outside premises: 115 µg/m3 Corresponding Air Quality Index (outdoors)[1]: 182 Air quality inside premises: 70 µg/m3 Corresponding Air Quality Index (indoors): […]
How much pollution do we breathe every day?
How much pollution do we actually breathe in every day? Are masks or air purifiers more benefiting to our health? Do we really need both? The answer to this comes down to how and where we are spending most of our time every day. There are two possible theories: masks might seem more effective since when […]
Are Purifiers Useless If Windows are Opened?
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 reduce chemicals coming from […]
When wind blows from the north, Beijing’s air quality becomes better
To the northwest of Beijing is sparsely populated Inner Mongolia. Thus, wind from there cleans things out. Here’s what happens on average to PM 2.5 levels with wind from different directions in Beijing: When wind comes from the south or east, PM 2.5 is above average. When wind comes from the north (on the far […]
Is There Less PM2.5 on Higher Floors? Does Living in a High Rise Protect People From Pollution?
Living on the 20th floor of a high rise building isolates people from the world. Cars, streets, shaokao vendors—they’re all farther away. So does that mean PM2.5 is lower on the higher floors of buildings? The Test Tristan from the Smart Air team tested this by taking laser particle counters from floor 1 to floor […]
Surgical Masks Surprisingly Effective Against PM2.5
There’s a fantastic educational poster from Greenpeace that I’ve seen in several places (for example, here on AQIcn). It offers great advice on masks, but then it says this: “No effect” it says. But when I read the cited articles, I saw no tests of surgical masks. But I should be nerd fair. Maybe they […]
New DIY Design Increases CADR 15% – Supplemental data
Methods Results were identical to my earlier tests of the Original DIY, Blue Air, IQ Air, Xiaomi, and Philips. Anna conducted the overnight tests in her 15m2 Beijing bedroom. Doors and windows were closed during the test (except for occasional opening during the first couple hours before bed—that random variation is one reason I use […]
Recruiting: Campus Ambassador
We are a Chinese social-enterprise founded by an Assistant Professor from the University of Chicago (with branches in India and Mongolia) dedicated to selling low-cost air purifiers and spreading awareness about air pollution. Our headquarters are in Beijing, and we have a modest, international, and passionate team committed to alleviating one of China’s biggest problems: […]