I bought Qingping and it’s best and worst purchase at the same time. On one hand it proved you need to open windows frequently and it’s cool to monitor co2 in p

I bought Qingping and it’s best and worst purchase at the same time. On one hand it proved you need to open windows frequently and it’s cool to monitor co2 in public places. On other hand it’s depressing good ventilation won’t happen for decades if not centuries and it’s unfeasible to open windows in super cold, hot or humid climates. Also, my measurements were different from author. On a plane co2 was pretty bad until AC was turned on (usually around midway boarding), then it hovered around 1000ppm. On a train it also stayed around 1000ppm.