Pete, here I would disagree with you. I would not use a software based thermostat solution. I would use a thermostat with embedded logic for reliablity that exposes control, settings and status to a PC based software solution. Not that technically it isn't very possible (almost easy), it just is not recommended for mission criticial functions like Heat control (even more important than Cool). This is especially important in freezing climate areas. If you are in Phoenix, probably less of an issue.