Hazardous Weather Alert

I decided to approach the smog problem like an engineer, so I bought a high-quality air quality sensor.

My original goal was to measure how much 3D printing affects the air quality in my apartment.

What I discovered was more surprising than expected: during winter, opening a window was worse for PM2.5 levels than running the 3D printer.

Opening the window caused a rapid spike in PM2.5, much higher than the printer itself. At one point, the printer effectively started helping air quality because I had already installed filters on it.

For context, according to WHO guidance, annual average PM2.5 should not exceed 5 ug/m3, and 24-hour exposure should not exceed 15 ug/m3 for more than a few days per year.

Theory is one thing. Real life is another.

Experiments

1. Closed room, around 8 m2

• Starting PM2.5: around 60
• Air purifier set to maximum power
• After around 30 minutes, PM2.5 dropped below 5

2. Apartment, around 75 m2

• Starting PM2.5: around 50
• Air purifier set to maximum power
• After 1 hour, PM2.5 dropped to 11 near the purifier
• At the point farthest from the purifier, PM2.5 was still around 20

3. Driving a car

• Starting PM2.5: around 130
• Closed air circulation, fan set to maximum
• After 10 minutes of driving, PM2.5 dropped to 25

While testing this, I also discovered that my car decides on its own when to disable closed air circulation.

It switched back after about 30 seconds every time. The service center told me this was normal and intended to prevent the windows from fogging up.

Modern technology.

I decided I would rather deal with humidity than breathe PM2.5 inside the cabin, so I used the Bimmercode app to disable that behavior and finish the measurement properly.

My Takeaways

Long term

• Fund replacement of old heating systems
• Live in a place where the air is actually clean
• Keep raising awareness

Short term

• Know how to reduce pollution locally at home and in the car
• Use purifiers where they make a measurable difference
• Be careful with opening windows during heavy smog periods

And maybe there is still more to add to that list.