Having co2 made it much much more aware to me to keep window open or open them and this effect is very long lasting for me, i'm doing this now for years and it stuck.
I can highly recommend buying a $60 or so co2 device.
Still way more than $60 but more reasonable for what you get. It's basically a $60 sensor that costs more because of WiFi and phone integration.
The indoor kits include a high quality NDIR CO2 Sensor from senseair.
You need a device that specifically quotes having an “NDIR” sensor and most are $100+
And it doesn't meassure anything else. So a good point that its not the same thing and if you want both, you probably need to spend 100+