Mitsubishi heat pumps with the "Hyper-heating inverter" technology are above 100% efficiency down to -15℉ (-26℃). They are 200% at 0℉ (-18℃), 300% at 32℉ (0℃).
Their capacity drops from 100% at 23℉ (-5℃) to 76% at -13℉ (-25℃).
Fujitsu has similar technology, as do a few others now.
100% efficiency on a heatpump is really, really, really bad. It's effectively like warming your house with electric baseboard heating which is very expensive, 4-5x the cost of natural gas in my area. Thus why I said they don't work great when its 10 below. Because they don't work great.
I decided on heat pumps and was lucky enough to find a reseller of Mitsubishi who mentioned his contacts there were looking for a cold climate home in elevation that wanted heat pumps to prove their tech.
Long story short, I put in heat pumps at a fraction of the cost of what it would normally cost. Now the benefit of the mountains as opposed to Denver is it rarely gets below 0 even if Denver is -15 the mountain low might be -5ish.
Yes efficiency goes down the colder it gets but when I owned the home I never had to supplement the heat pumps to keep the house warm. It would pull 120F heat when it was -5 out. Again when its -5 natural gas is a lot more efficient but the idea is its not -5 all year. The first year I had them my electric bill averaged $650ish to $310. Also I got AC in the summer as a bonus.
But the average house and older homes especially (in northeast esp) have poorer insulation. Heat pumps are still very expensive and for many need backup for extreme weather or require major inconvenience.
Not to mention how expensive electricity is, and the fact that it's getting more expensive.
insulation always pays for itself multiple times over. Why is rhere no financial oroduct like mortgage that wouldballow you to direct the energy saving from extra insulation into repaying installation cost ay favoirable tax-free terms and low interrest rate like mortgage?
See also how the real estate sector was whining in the recent years about the (quite mild !) new insulation laws, seemingly only caring about their short term profits. Well, hopefully they have shut up now (or maybe not, with, now that we ARE in the predicted crisis, serious laws coming up, and at the same time, the real estate bubble popping).
She has gas heating, while I have electric (which got something like +75%, but starting from a lower baseline), and I don't even have a heat pump !
But then my insulation is average (and I haven't even started heating yet, though to be fair should have for at least one week, this winter is insanely warm so far), while hers is supposedly very bad, probably one of those apartments who have been recently announced will be illegal to rent soon.
And she got furthermore protected by the government which froze gas prices - someone will have to eventually pay those ×5-×10 bills !
In the medium-long term, methane is probably less viable than electricity, which is easier to transport and can come from a variety of sources including 60% efficient gas turbines.
Good to hear on the heat pumps though. I’m planning to eventually replace the propane boiler with them.
When I bought the home I had a company come to help me plan the heating and I don't fully understand the science but the home is built to keep heat in with the windows and no attic.
The hyper heat can pull 120Fish heat down to -15F
You might be an order of magnitude higher than reality here.
I do live in the French Alps (relatively cold) in a 160m2 house warmed with an heat pump. My bill is around 600-800€ per year, not per month. My house is from the 1970s with an average insulation from the 80s
I do not see how you can get 600-800$ per month, excepted if you do live in a -25˚C climate and in a house insulated with a sheet of paper. But then you will probably get an even worst bill with a gas boiler.
Quick google shows that electicity in France[0] costs roughly 1.6x more than natgas. For Washington State this ratio is around 2.45x.
Eyeballing this graph[2] that corresponds to breakeven outside temperature of <-20℃ and -8℃ respectively for 40℃ output (~-18℃ and 0℃ for 50℃).
[0] https://www.globalpetrolprices.com/France/ [1] https://www.bls.gov/regions/west/news-release/averageenergyp... [2] https://support.sefaira.com/hc/en-us/articles/115000249971-A... -> scroll down roughly 2/3.
Interesting perspective, thank you. Considering that the average winter temperature in Seattle (Washington) is around 3-4˚C [1], it is far over the breakeven.
It is even more true in my case: my system is is a water-water geothermal type. They do maintain maximum COP (4-5) and maximum power independently of the outside temperature. They are perfect for cold climate.
For the little side story: My heatpump has been installed in 1987 by the previous owner of the house and I believe he was truly a visionary.
Nobody was talking or even speaking about heat pump at that time. From his own words: people of the neighbourhood took him for a mad-man when he said in the 80s he would warm his house with the cold water from the river. Facts are that his system is still running 35 years later and provided a cheap, reliable and low carbon source of heating for over 3 decades.
[1]: https://weatherspark.com/s/913/3/Average-Winter-Weather-in-S...