I have read multiple scenarios but none completely apply to my situation. I have a very OLD home approximately 4000sq feet in size in cold climate Canada. It presently has a propane furnace and an oil furnace that heat 2000 sq each. Oil being the price it is has limited how often we choose to turn on the oil furnace but as the ductwork is joined through common delivery pipes, the propane is able to deliver to the whole house, but not efficiently. We worked out with a energy equivalency calculator that at present pricing electric heat is equivalent to oil when prices reach $1.58 per litre and it is presently at $1.98 so it has to get pretty cold to make us turn that furnace on and we have started subsidizing the kitchen with an electric space heater.
We are waiting for the installation of a hybrid heat pump that will have an air handler connected between the the two systems and become the primary heat cool source with the other two working as second and third options consecutively. To make the setup even more complicated there is a wood fireplace located on the propane controlled side of the house / family room.
Two independent thermostats have always controlled their respective zones, and this worked well until recently when prices jumped. In an attempt to try and more effective control this house I just installed a google nest thermostat on the propane side as a test see if it would help optimize control. Here’s my problem presently. I want the nest to read the situation eg. if I have a fire burning and the family room temp goes above 20deg C I want the fan to trigger and distribute that extra heat and it doesn’t no matter how low I set the cool set point? When I add a third source of both heat and cold ( heat pump ) will it be able to control it in descending priority eg. 1 heat pump, 2 propane, 3 oil as a last resort and can I program it to accommodate the wood stove or is that not a possibility? There are also other independent heat sources in this house I haven’t mentioned ( gas fireplaces 2, in floor heating basement, and old baseboards) but let’s leave those out of this equation as this is confusing enough already.
