[throwaway9d0291]

Any CO2 sensor (part) that gives you the ability to turn off ASC should work just fine and most of them do, you just need to trigger it.

Personally, after trying out a bunch of sensors, I use the Sensirion SCD30.

As for devices, I'm not aware of a consumer device that I'd recommend. If you're willing to do at least a little bit of DIY, Watterott [0] sells an SCD30 hooked up to an Arduino-compatible MCU with WiFi, a red/green/blue indication of CO2 levels and ASC disabled by default [1].

It's an open-source hardware design and software [2] and has a few reference firmwares [3], including one [4] for MQTT.

If you want to go a little bit further, I'd recommend an ESP32 with an SCD30 and ESPHome [5]. That's what I use myself, mostly because I already had the sensors prior to Watterott's product existing.

[0]: https://shop.watterott.com/

[1]: https://shop.watterott.com/CO2-traffic-light-Plus-version-Wi...

[2]: https://github.com/watterott/CO2-Ampel

[3]: https://learn.watterott.com/breakouts/co2-ampel/

[4]: https://github.com/mariolukas/Watterott-CO2-Ampel-Plus-Firmw...

[5]: https://esphome.io/