Which is cheaper to operate?
I am in sacramento ca. It freezes here sometimes but rarely and the summer is pretty warm but we get a nice breeze off of the delta so it normally cools down good at night. I built the house last year its has r-38 in the ceiling and r-19 in the walls and the roof sheating is radiant barrier type. If it cools down at night we do not need to use the AC. This year we had the record # of days over 100 degrees, and it did not cool down at night so we had to use the AC for a week strait. We have a Trane 14 seer unit and my electrical bill went from $80 to $130. Many people I talked to had $500 electrical bills and their AC units would not even keep up. We were maxing out our unit pretty good, but it kept us comfortable.
Now in the winter I have an 80% efficent propane heater and my bills are about $300 a month in propane (100-150gallons). My neighbors house (heat pump) is smaller but her electrical bills have never been over $140. It just seems to me that there is no way a heat pump would cost $250 (assuming $50 goes to water heaters)a month but wanted to ask the experts here.