[ioulian]

For people who use Home Assistant, I've gone with DIY route with ESPHome [1] and senseair CO2 sensor. You can buy those sensors for +- 26 USD on AliExpress. Together with 5 USD, ESP32 devkit, it's mostly "solder"-n-play.

Of course, I only have one of them, so I can't say if they are accurate, but I just need to know if the CO2 levels are normal (+- 400ppm) or high (+1000ppm), to open a window. I have tested it with just blowing on it, the CO2 value jumps up, putting it near a window, goes directly to +- 400.

I haven't had any strange readings with it, ESPHome developers really made an excellent product, that is stable and "just works". You can even calibrate the sensor by putting the it outside (but I haven't really bothered with it).

ESPHome has also support for a lot of other sensors that you combine on a single ESP32 module.

[1] https://esphome.io/components/sensor/senseair.html

[plett]

I attached a cheap IKEA Vindriktning PM2.5 sensor to esphome to get air cleanliness data into Home Assistant [1]. That's also very simple to do - solder some wires and write a few lines of yaml and it shows up in the web UI. I bought two of them and they are accurate to each other, so the sensors appear to be acceptable.

[1] https://plett.uk/posts/ikea-air-sensor/

[jve]

They are extremely inaccurate. But relative measurement is OK - you can see rising or falling pollution. When I put one in kitchen it "died" pretty fast - I think the cooking oil grease got onto the sensor and it is game over for me. Shows MAX PM2.5 all the time.

[noja]

Do you know if the new ikea air quality sensor has the same fan as the first one? The original had a fan that would turn on and off every ten seconds.

[joecool1029]

It does but it's a different sensor and doesn't pulse as frequently (I think it has a weekly pulse to clean it... SENS54 is the sensor if you want to look it up)

[eternauta3k]

You could measure (almost) pure CO2 sensitivity by putting it in a pot with a glass of sparkling water.

[whamlastxmas]

Can’t wait for the Thread ESP32 units to be better developed