this post was submitted on 12 Sep 2023
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Oxford study proves heat pumps triumph over fossil fuels in the cold::Published Monday in the scientific journal Joule, the research found that heat pumps are two to three times more efficient than their oil and gas counterparts, specifically in temperatures ranging from 10 C to -20 C.

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[–] [email protected] 19 points 1 year ago (1 children)

My air heat pump has been ticking away happy for 15 years with no issues. It's worked fine warming up the house when it's -20°C in the winter and cooled nicely in the up to +30°C in the summer.

I do supplement it using electric heating and a fireplace though.

[–] DarthBueller 5 points 1 year ago (2 children)

Thank you for responding and sharing your counter-experience. Greatly appreciated. What keeps your unit from icing over? Are they designed differently in northern climates?

[–] [email protected] 12 points 1 year ago

Here's a good video showing how the heat pump will reverse and basically dethaw the coils when it freezes over: https://youtu.be/7J52mDjZzto?t=1317

[–] [email protected] 4 points 1 year ago (1 children)

They're spreading all over the Alps too. Easily a 50° temperature difference between summer and winter, and they tick over nicely for years with no problems

I think in Europe it's a fairly common method now so reliability has been sorted out.

Generally the US is a decade or so behind everyone else though so it might take a while

[–] [email protected] -4 points 1 year ago (2 children)

The COP coefficient falls down drastically to 1 as soon as temperature drops below -5C and they basically start working as an electric heater. It wouldn’t be a problem if I wasn’t living in a country with the most expensive electricity in Europe which is produced mainly from coal…

[–] alvvayson 7 points 1 year ago (1 children)

Then you're looking at the wrong models.

The Mitsubishi H2i has a COP of 2.88 at -15 C (5 F).

There are also models with COP above 2 at -30 C.

Yes, a typical A/C isn't designed for subzero temperatures. But you gotta get the right heat pump for the right climate.

For cold climates, it does get more expensive and less efficient and at some point it will always be cheaper to just burn wood or fossil fuels. But with the right heat pump, even very cold climates can get most or all of their heating cheaply with a heat pump.

[–] [email protected] 1 points 1 year ago (1 children)

Hah look at the downvotes, you can’t have civilized discussion these days.

Your last paragraph and my last sentence is the whole culprit for me. The money I have to pay here for good heat pump with COP 2 at -30 and the associated electric bills have currently no chance here to ever be cheaper than burning gas either nor more friendly for the climate where my government burns coal to produce electricity.

And no, I cannot install enough solar to power this heat pump in the winter or offset the cost of electricity during summer (inverters already turn off in the summer, no electricity is produced as too many neighbors have solar and voltage rises above shutdown threshold in the grid)

[–] alvvayson 1 points 1 year ago

Solar in winter for high latitudes is never gonna work, fully agree on that.

But at some point a hybrid system will be cheaper for part of the year than a pure gas system, at any latitude.

Whether it justifies the investment is indeed a cost/benefit analysis.

Downvoting on Lemmy is toxic, fully agree on you there. It really stifles healthy discussion. It seems Lemmy is engineered by communists who only want agreement lol. 😂

[–] [email protected] 5 points 1 year ago

Yeah that's just incorrect. People wouldn't use them then. All new build chalets have them