[loufe]

I just bought an AirGradient sensor and set up home assistant. What an absolute joy, both experiences (though I had issues building AirGradient's firmware due to some issues on their end, to their credit their dev team told me they're going to adopt my recommendations) are streamlined and professional and super easy to set up for a techie. I've already got in the habit of opening the window to the office as the sensor detects elevated CO2 (happens faster and more often than expected, very glad I invested).

However, I also bought a 3 SCD41 sensors and ESP32 C3 Superminis from the most reputable sellers on AliExpress, that's been an abject failure. I wanted additional sensors in other rooms less at risk, and wanted to try using ESPHome and putting together my own soldered little devices. Got counterfeit sensors (no laser engraving on the side as Sensiron indicates is without reception the case in genuine parts) and either counterfeit or defective microcontrollers (cannot connect to wifi, even 2.4GHz WPA2, a common enough problem from my research with ). The spread from reputable sellers in NA was absolutely ridiculous and worse then buying premade pieces by a large margin.

All to say, as fun as DIY is, I'm grateful to have trustworthy products available affordably. I'll still block internet access and leave them on a dedicated IoT VLAN, but I can at least not worry it's going to incorrectly label the air quality for a child's bedroom. I'll probably pick up 3 of the CO2 sensors from IKEA, if reviews look good.

[scosman]

I suggest the SenseAir sensors. They don't seem as susceptible to fakes, and auto calibrate when exposed to fresh air. Supported by ESP home so build is simple.

Any evidence the Ikea sensor are actual CO2 censors and not just cheap "eCO2" sensors? Lots of the "CO2" censors our there are just cheap VOC censors with an calculation to estimate CO2.

[bjoli]

I really hope that is CO2 and not eCO2.