[snuxoll]

Power outages aren’t an argument against heat pumps anyway. Without power my central fan can’t run and thus my forced air natural gas furnace is dead in the water.

Anyway, where I live in Boise most utility outages are due to physical damage - whether that be animals, auto accidents, extreme weather (not “it got cold”, but wind gusts toppled a tree that brought down a utility pole), and fiber seeking backhoes. Even had the gas get shut off at my old house because an auto accident hit some equipment a street down causing a gas leak.

[rainbowzootsuit]

I will compare some nominal power inputs to add perspective about the dead in the water forced air furnace.

I will compare a nominal 3Ton = 36,000 BTU/h (10.55kW) furnace+AC running at about 1200CFM with gas fuel input at 45,000 BTU/h to similar heat pump system outputs and electric resistance heat.

The central furnace fan is probably about 1/2 horsepower rating (372W) and has some design tolerance built in where the brake horsepower is less than this. The heating output at 80% efficiency is 36,000 BTU/h (10.55kW). This output is constant regardless of outside temperature. This could be run with a small inverter generator or possibly a robust battery system in the 20kWh range with appropriate solar.

Note that the heating input for this size of furnace can go up to ~155,000 BTU/h (45.4kW) with only the same amount of fan power needed in the form of electricity.

Looking through Mitsubishi literature, a 3ton hyper heat pump (SUZ-KA36NAHZ) at 17f can deliver 25400 BTU/h (7439 W) of heat output with an input of 2490 W. You will need strip heat to supplement this output to make up the difference (10.55kW - 7.439kW = 3.1kW of electric heat) So total power input is 3.1kW + 2.49kW = 5.6kW input for 10.55kW output. This might be short a few hundred watts as you still have to run the fan. This could be done with a larger portable generator.

http://mylinkdrive.com/USA/M_Series/R410A_Systems-1/Outdoor_...

Electric resistance heat would need the full 10,550 W to equal the output and now you need a relatively large fixed natural gas generator and transfer switch.

My personal opinion is that a heat pump system for normal operation with a natural gas or propane furnace as backup emergency heating is a good option to cover emergency situations as much as possible without adding an additional separate system like a wood burning heater or similar device.

[OJFord]

Would you even have gas for it to burn if there was no electricity to run its meter?

[josephcsible]

Every gas meter I've ever had has been purely mechanical. Have you ever seen one that needed mains electricity to work, and that acted like a shutoff valve when it lost it?

[irq]

You’re right about the gas meter, but the town/city infrastructure necessary to pump gas through said meter does rely on electricity. They have backups, but for how long? Long enough to ride out most power outages, but nothing unexpectedly extended.

Many rural houses have tanks on site because there are no public gas lines to connect to. My house has a 1000 gallon tank and is not vulnerable to the above, for example.

[NickNameNick]

Most reticulated gas networks use the pipe network itself as the storage facility.

eg: https://en.wikipedia.org/wiki/Natural_gas_storage#Pipeline_c...

There may be more than a day of capacity just in the pipe network.

[NavinF]

Yes, natural gas pumps run on natural gas.

I'm sure there are exceptions, but I've never heard of one.