Heat Pump

I have learned that, though natural gas is the cheapest heat source in Taos, the price that we pay does not cover the damage to our environment and climate. Production of methane (natural gas) releases a lot of methane to the environment, and methane adversely affects the climate much more than does carbon dioxide, which is produced when gas is burned. Of course, in order to get heat out of methane, I must burn it, producing carbon dioxide!

Heat pumps are somewhat like a refrigerator, moving heat from one place to another by compressing a refrigerant (which releases heat) and then evaporating that refrigerant (absorbing heat) in another place. Heat pumps are relatively efficient down to below freezing, and some to nearly zero Farenheit.

So I have been trying to get a heating contractor to provide an estimate, or even answer the phone, for several months. I finally found a local vendor of Mitsubishi heat pumps, one of the better brands for working in cold climates. Since I alreay have a ducted heating system with a gas furnace and blower, I would want heat pump coils that can be installed in my existing system. Then, if the weather gets very cold -- too cold for the heat pump -- I can still use the gas furnace to stay warm.

But Mitsubishi has at this time only a heat pump with air handler (the blower), and plans to release coils that can be integrated with an existing furnace later this year. So, we shall see.

November update: I can now measure the power used in 15-minute increments. Last night was very cold (6°F at 7 am) and the power consumption appears to be about 1 kW overnight. The nights are about 12 hours long, so the battery should be just about enough.

Wiring

I have a 30 Amp outlet under the mechanical room -- intended for clothes dryer. But now a clothes dryer is available that is basically a dehumidifier, and does not need so much current. It seems to me that I can divert this 30 Amp circuit up to the mechanical room, install a subpanel, and run the heat pump off that. That would remove the need to run a new cable from the power panel in the garage.

Turns out that the wiring is not easily accessible. I will need to remove part of the wall in the laundry area (behind the dryer up to the ceiling).

I plan to install an electric sub-panel in the mechanical room from this 30 Amp circuit: