re: Question for OT HVAC engineers

The only real savings I can see with constant temps and using a heat pump is to try to heat your house during the daylight hours, when the heat pump is more productive and efficient, as opposed to heating it a lot when you get home and it is dark and colder.
This will lead to the auxillary heat coming on as well, which will drive up your power bill.

I can not see the savings benefit in any type "constant" temp using AC, or a gas furnace heater.