How should someone contact you? I looked into setting up something on an Arduino last year, and the CO2 sensor I ended up purchasing was not very good, so it's cool to see someone thinking about this problem domain.
We use the Senseair S8 CO2 sensor which is very accurate and of high quality.
Some of the TVOC sensors give an estimated CO2 level (eCO2) which is not recommended because these values are not very accurate.
Yes the Senseair S8 is very good. Only problem is that the automatic baseline calibration sometimes needs 7-10 days to kick in. But you can also do a manual calibration.
