Sure, totally agree with you on that for truly cold climates. My only note would be that using natural gas as a backup/emergency source for cold climates only makes sense if you have existing gas infrastructure there... and it still makes sense to upgrade to a heat pump assuming that you don't live in a climate where it's just frozen constantly (e.g., parts of Canada, Alaska, etc)
Even just routing a new gas pipe to your HVAC closet can easily be $5-10k, which would erode all potential savings during the truly cold parts of the year... not to mention the additional cost of a furnace + emergency heat wiring etc.
> that assumes 100% efficient gas furnace. Cheaper furnaces are ~80% efficiency. Really good furnaces are ~95% efficiency.
>> natural gas is around 4 cents per kwh. Gas furnaces are extremely efficient, buts lets round up to 5 cents/kwh to be conservative.
> So for the periods when it's mild, but heating is still required, the heat pump is an obvious winner
>> it is wonderful for 3 seasons of the year. I think all new construction should have one. But the cost to heat during winter is ridiculous.
>> Heat pumps as a _sole_ heat source are not cost competitive in cold climates.
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