What are the best air heat pump systems that use the heat pump for cooling but use a natural gas heater for heating?
Are there any reasons to not consider that design instead of an all-electric heat pump for cooling and heating? Obviously we are hoping to save on heating costs by using cheaper natural gas, but I understand it may not be so straightforward, and in certain temperature ranges using the air heat pump for heating may be more efficient than natural gas. I guess the perfect unit would sense those conditions and switch between electric and natural gas heating based on outside conditions?
I also understand that an air heat pump does not work well with the temperature outside below 40F, so the unit would of necessity need to switch to natural gas in that case.
I would have preferred the simplicity and low operating costs of geothermal, but I have sadly concluded that this is a technology only for the extremely rich.