[bettered]

We recently replaced our A/C with a HP, keeping our gas furnace for "emergency heat" instead of "heat strips" which are frightfully expensive. We just got our 1st billls for less than a month on the new system. The electric bill was the same as the previous month at $110, but the gas bill was $80 vs last month's $120. This is remarkable because during the conversion we were running our gas logs - which have a higher BTU input than our furnace!

The em heat (furnace) is set to come on below 40 deg, and I have setback set for 64 until 10:30 am, by which time outside temp is generally above 40 even when the overnight low is in the 20's. The HP seems to run a lot, but that's not reflected in the bill. My opinion is that it's a struggle for a HP to extract warmth when the outdoor temp is near freezing. So far, I'm very satisfied with the change.