Suppose you had complete control of your thermostat. What would be the most efficient operation in this case:
You have a dual fuel system and are between the balance points. The thermostat calls for heat but the HP needs to defrost (cooling the house for a few minutes), so it turns on the furnace. After the HP is done defrosting should it turn off the furnace to take over or let the furnace complete the cycle?
The furnace is more expensive, but the cost of starting up the heatpump may outweight the cost of keeping the furnace on for a few more minutes. Also having the heat pump take over from the furnace would decrease the time it would take until the HP needs to defrost again, thus turning on the furnace more frequent.
Any experience or thoughts on this subject?