My wife and I just built a new home in Minnesota and had the Bryant Evolution Extreme Heat Pump installed, paired with a 97% efficient furnace with the modulating speed blower.

I'm new to the world of heat pumps, so I'm curious about a couple things.

1. When on "Hybrid Heat" the furnace seems to run more often than I think would be necessary, given that our temperatures have only been getting down to the low 30s. Does this happen to help "warm up" the system in some way when it's just turning on? If I select "Heat Pump Only" on the evolution control, the heat pump does a fine job keeping the house warm without the furnace.

This leads to what might be the bigger question...

2. How does the "Hybrid" system know when to switch between the furnace and the heat pump? Is it based on the # of degrees it is trying to warm the air inside, or the exterior temperature, or some other factor? For the lowest operating cost, would I be best served to leave it on the "Hybrid" mode or keep it on "Heat Pump Only" mode until the nighttime temps get closer to the single digits?

3. With this sort of system, will I see lower operating costs by having the program drop the temperature just a few degrees during the day, then bring it back up before we get home in the evening, or would it be more advantageous to set the temperature very low while we're gone, to minimize the amount the system needs to run while we're gone, then turn it way back up before we get home, in essence, have it not work much at all, then a big workload to warm it up, or a lower but more consistent workload?