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Who has gone all electric in a colder climate?

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La Bibliotecaria Feroz:
We want to replace our gas furnace with an electric heat pump. We live in Denver, so the winters are medium cold. Please don't try to talk us out of the furnace replacement. My husband cannot smell gas, so we are trying to eliminate gas from our home, and we also have like a 10 to 15 temperature difference between the upstairs and downstairs and we do not want half measures. It's not like we can afford to move, we have five people and 1800 square feet, we need the basement to be livable!

Anyway, I had the first visit toward getting an estimate today, and the guy was trying to convince me that I do not want to go all electric because my electric bills will be too high. He says they are really pushing hybrid systems, where the backup heat runs on gas. I think there are some folks around here who have made the switch, so I wanted to hear what people's experiences have been. Is he right that it's a huge mistake to go all electric?

We live in Seattle. We replaced our old gas furnace with a Daikin heat pump system a little over a year ago. No gas furnace backup, and I'm pretty sure our system didn't come with electric resistance heating backup either. This is of course more of a mild climate than you have. We had an unusually cold week this winter, with temps hovering in the 15-25F range for three days straight. Our electric usage went up dramatically during this time, and also our system was unable to maintain our desired temperature when the outside temp was below 20F. It was still blowing warm air, just not quite enough of it to make up for heat lost to the outdoors.

We have a house with about 2,000 finished square feet and about 500 square foot unfinished basement. It's 100 years old, not well insulated at all. Pulling data from our smart meter...we use about 20 kWh in a typical spring/fall day when the heat pump is idle. On a more typical Seattle winter day with temps in the 40s we use about 50 kWh (so 30 kWh on the heat pump). The coldest day with a low of 15F we used 162 kWh (142 kWh for heat pump). In other words, we spent about $20 to heat our house that day. Such days are extremely rare here though.

All this is to say that in a place like Denver where the average daily low is about 20F lower than Seattle in mid-winter, you're probably going to want something besides just a heat pump. Whether a heat pump with electric resistive backup will be good enough, or if you really will save a bunch of money by having a gas furnace for the cold days is something I can't answer for you.

We have, three times

First was in our condo in Quebec, where we had a heat pump coupled with a couple baseboard heaters. Worked brilliantly, even down to -30F. IIRC the heat pump functioned down to -14F before a resistance coil kicked in to make it basically a radiant heater with a fan in it.

Then we removed the 40 year old boiler in our previous home in Maine and have installed four heat pumps (a single exterior and a triple) plus a single 8k heater for extreme weather (might be overkill).  We are also putting in s pellet stove as much for the ambiance as for a back up heating system for power outages (the pellet stove will have a power backup). We will occasionally get nights that go into the single negative digits but going colder than the rating on our heat pumps (-17F) has not happened in the last 40 years.

Paper Chaser:
I bought an all electric house in the lower Midwest last summer. Google says my location sees average low temps pretty similar to Denver, but average highs stay about 10 degrees cooler here. Denver sees ~30 degree delta between low/high temps each month while I see ~20 degree deltas. Similar lows, but I don't get as warm each day.
It's been a full remodel down to the studs, so no full time occupancy yet, but my electricity consumption in Dec was about 6 times what it was in July.
It has a heat pump AC with forced air furnace (not a ductless mini-split style). I kept the indoor temp set to 60F during colder months, and kept the AC set to 80F for dehumidification purposes in warm months.
I don't have the water heater on since there's no need for hot water.
I've added new windows and exterior doors since Summer as the old ones were damaged and leaked a lot of air.
Insulation and air sealing was below current standards upon purchase, but is being improved as the rehab moves forward.

With it being an unoccupied rehab, it may not be the best data point, but I think it's safe to say that your cold season usage will be pretty high. A lot of it depends on how well insulated your home is, and how your specific furnace or heat pump system is specced and implemented in your home.

If the heat switch allows you to eliminate gas service to the house altogether I would consider that you are avoiding the gas fixed charge which here at least is a couple hundred bucks a year before you use a single therm, helps cover higher winter costs. And insulate insulate insulate. The tech definitely exists to run electric only in your climate but you have to seal the place. Your utility probably has a program to do it fairly cheaply and you are likely eligible for substantial credits under the IRA (check out the rewiring America calculator for number specific to your state/income/etc.)


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