I have done a bunch of writeups, in this category [1]

The weather station post in particular with the sensors is here [2]

[1] https://partofthething.com/thoughts/category/electronics-and...

[2] https://partofthething.com/thoughts/weather-and-air-quality-...

Thank you.

+1 for the air quality sensors question. I only found 1 for CO2 levels, and it is not connected. And even that one costed $120.

Tuya Zigbee air quality sensors on AliExpress start around $20. I can't speak to their accuracy, but they are supported by Zigbee2MQTT and provide a CO2 reading.

https://www.zigbee2mqtt.io/devices/TS0601_air_quality_sensor...

Answered here: https://partofthething.com/thoughts/weather-and-air-quality-...