I expected after COVID there would be much more focus on air control/monitoring. How nice would it be to have constant air measurements in neighbourhoods and inside houses. And not only CO particles, but a wide variety.
Unfortunately I see hardly any focus on it anymore.
I got a CO2 sensor too, cheap but not entry level (about €125). It also does TVOC, PM1.0 and PM2.5.
One reason was I "balloon" sealed an unused chimney (old house) for the winter, that was the main driver of ventilation (and drafts).
If I don't crack a window, me, desk-working in a ~85m³ room pushes the reported CO2 from 400 to nearly 800 ppm by lunchtime, though the device is close to (not on) my desk which probably skews it a bit. I don't have any data to compare though, I might remove the balloon when weather improves next month to see.
There's also a gas hob(!) in the adjacent kitchen, the other VOC/PM readings are elevated for as long as 12 hours (depending on how badly my cooking went :),
even with a hob extractor fan running and permanently open intake vents.
The speed of CO2 increase and persistence of the effects of cooking were both a surprise to me.
I bought a CO2 sensor, and found that the CO2 levels rise to unhealthy levels in like half an hour in my room without opening my window. Since then I only sleep with a window slightly open, and open it periodically during the day.
I also run an air purifier all the time, but I cannot yet measure it's efficacy, because a particle counter is like 2-3× more expensive than a CO2 sensor, so I haven't invested in it yet.
A PM sensor is 2-3 times cheaper than a decent CO₂ sensor if you're willing to get your hands dirty. Look for PMS5003 (or PMS7003 which is pretty much the same beast in a different package), and any ESP32 dev board (they're dirt cheap) + ESPHome as firmware.
Yep, I leave the fan on all the time to circulate air in the house. The levels seem to range from 450-550ppm. I was surprised at how low that is considering this is a newer house.
450-550 is great, especially since ambient levels outside are about 420. I live in an old house and with windows closed and no hvac fan running, rooms only take about 30 minutes to get up to 800ppm with one person in them. After an hour or two they get up to about 1050ppm. With two people, they get > 1000 pretty quickly.
Looking at metrics from the sensor is pretty interesting too. You can see, to the minute, when a room went from unoccupied to occupied.
This would be nice, but I fear we can go too far down this road, particularly with children.
Hormesis is important for our health: exposure to periods of starvation to induce autophagy of senescent cells, exposure to allergens and less-than-lethal pathogens (at a young age) to train our immune systems [1,2], etc.
Obviously we want to minimize heavy metal, PFAS exposure, etc - but living in ultrapure environments risks throwing the proverbial baby out with the bathwater.
Absolutely in favor of better environmental monitoring, but we need to be very selective about the specific things we don't want.
