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 […]
Author: choonkhin
Smart Air Indoor Air Quality Audit in 3E Space
Air Quality Audit Report Date of audit: 27/05/2017 Audit conducted by: Yap Choon Khin Paddy Robertson Air quality monitor: Dyloc DC1700 Pro AirVisual Node Audit location: 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 […]
How much pollution do we breathe every day?
When people ask me how they should protect themselves from air pollution, I’ll say you need a purifier for indoors and a mask for outdoors. Many people have both (great!) but which one is benefiting your health more? Do you really need both? The answer to this comes down to how much air pollution we’re breathing […]
Are Purifiers Useless If My Window is Open?
Are Purifiers Useless If My Window is Open? 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, […]
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 […]
New DIY Design Increases CADR 15%
After I made my first DIY, a design magazine called me up to interview me. I said, “You realize this has no design in it, right? It’s just a fan and a filter.” Now I actually have a design improvement! I’m calling it the DIY 1.1. The Problem The data shows the Original DIY significantly […]
Surgical Masks Surprisingly Effective for 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: […]