I live in metro Atlanta. My GE furnace is 28 years old and on its last leg; my Trane condenser unit is 12 years old. My house has 3 floors, including a finished basement, for a total of approx 3200 sf. I want to replace the single existing system with 2 new systems: one for the main floor & basement, and one for the upstairs bedrooms. I have had two contractors perform load calculations, and both proposed a 2.5 ton system to replace my existing funace in the basement, and a 2.0 ton system to be installed in the attic.
Both contractors have proposed Trane systems. One recomends a traditional gas furnace (XR80) and A/C condenser (XR13) for both systems (80,000 BTU in basement, 60,000 BTU in attic), while the other recommends a heat pump (XR 13) and 48,000 BTU duel fuel furnace (XR80) for the basement plus a heat pump (XR13) and 2.0 ton air handler for the attic. I am considering upgrading to an XV80 furnace based on discussion I've seen on this web site.
I have no experience with a heat pump system. One contractor swears by them and the other does not recommend them. It seems like a wise investment for the duel fuel option, particularly the way gas prices have skyrocketed. One concern is with the all-electric air handler for the attic. Sometimes the temperature in Atlanta can dip to 10 degrees during the winter, and I've heard that electric systems are not very efficient below 35 degrees. Will the warm air from the main floor (gas furnace) keep the upstairs comfortable in these extreme conditions?
Any input from you experts would be greatly appreciated.