As we've discussed elsewhere we had our 45 year old gas furnace replaced this spring with a heat pump both because it was 45 years old and because a new heat pump will be cheaper to operate and also because it meant getting central a/c as part of the deal, essentially for free. It also meant that we could move the air handler to our attic, freeing up space so we can expand our kitchen by renovating to make refrigerator space where the old furnace was and putting a big pantry cabinet where the fridge used to be. (that part will be done this fall once our contractor has time) A/C season seems to have ended with a whimper this year after a fairly cool summer. According to the nest thermostat, which shares the data, we used the a/c about 40 hours this entire summer. Going with a baseline of 300 kwh/month without a/c we used about 80 extra kwh running it. It will be interesting to see if using the heat pump proves to be as much more economical as my rough calculations were. Last winter we spent upwards of $200/month for gas, mostly for heat since the only other gas appliance we have is the hot water heater, which runs about $20/month for usage in the summer.

We had to spend $1300 replacing a section of our gas main when we dug out the koi pond to put in the front patio. I would have loved to put that money towards a heat pump water heater so we could cancel the natural gas service which has a $15/month connection fee plus usage but the plumber convinced us to wait a few years because heat pump water heaters are still in the early stages and supposedly newer, better models come out every year. Also, though, we got a $3,000 tax credit for switching to the heat pump for space heating, and can get another $3,000 credit when we switch the hot water heater, you can't get two credits in one year, so I suppose we'll still come out ahead assuming that the credit still exists in 2-3 years when we convert the hot water heater to a heat pump system.