FallenDemon:
Mirith I totally agree with you. I just do not know how to wire everything up and write the code. Could you look at me temp controller code and see if I can use that with some adjustments?
Assuming simple bang-bang control like you have, then all you need is to do is basically read the C02 sensor and feed it into temp. It would work exactly the same. Then whatever you do with output, you would do it the same with with the value. You might need to adjust conversions, but that is about it.