• regul@lemm.ee
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      3 years ago

      The coldest temperature ever recorded in the UK is -27. That’s right around the inflection point for where heat pumps become less efficient than electric heaters. Until the gulf stream fails, the UK is pretty safe to use heat pumps everywhere.

        • cygnus@lemmy.ca
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          3 years ago

          I’ll chime in here since I own 2 heat pumps and live in a cold climate (often below 20C). Our house is heated with 100% electricity and after installing heat pumps our power bill dropped by about 18%. That includes all electricity, not just heating, so the gain in heating efficiency was very considerable.

        • abhibeckert@beehaw.org
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          3 years ago

          Generally, cold climate heat pumps are an efficient source of heat down to -15 degrees Fahrenheit

          “Generally” is the wrong way to approach this. What you should be looking at is the specific capabilities of the actual system that you are considering installing. Some of them can go much colder.

          If the Mitsubishi FE18 isn’t efficient in your climate… then don’t buy that unit. Simple.

          If it’s really cold where you are… then you could consider a ground source heat pump instead one that uses air as a heat source. The ground doesn’t get anywhere near cold to have efficiency issues no matter where you are in the world and ground source heat pumps don’t cost all that much… though they do require a bit of digging.

          Also, if your heat pump is inefficient for a couple really cold weeks a year… oh well. You’re still coming out ahead because it’s very efficient the other 50 weeks a year. It’s not like they stop working at extremely cold temperatures, they just produce a bit less heat than you might like for the amount of power consumed. Maybe they’re “only” 80% efficient instead of 600% efficient… you know what else is 80% efficient? Heating with gas.

    • nous@programming.dev
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      3 years ago

      So? It is basically always as efficient as resistive heating at its worst, and the vast majority of the time it is massively more efficient. And even then they can remain more efficient even as low as -25C and might need resistive heating backup at places that get below that. But even in places that can dip below that they are often not that cold all year round. So overall throughout the year they are way more efficient on the majority of days even if you need a less efficient backup system.

      We really need to think of the whole situation rather than just focus on the but sometimes part of the problem. Yes, sometimes they dont work as well. But overall through a year for the vast majority of places a heat pump can be all you need and is a lot more efficient than other heating systems.

        • nous@programming.dev
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          3 years ago

          And what point does that happen? According to the article and other sources say similar things:

          Even at temperatures approaching -30C, heat pumps outperform oil and gas heating systems, according to the research from Oxford University and the Regulatory Assistance Project thinktank.

          And the lowest recorded temperature in the UK since 1961 is -27.2 °C. So the times you need to fall back to resistive or other backup systems is 0% of the time. And what do you count as a cold climate? is 0C cold? or -10C? -20C? I know many people that would say yes at any other those and I bet there are others that live in places that go way lower. Yeah, what you said is technically true, but without these numbers is almost a meaningless statement. In the UK, and most of europe this article is basically saying that heat pumps are more effective than other sources of heat even at colder temperatures and it takes extremes before they require alternative heating methods.

          The way you worded your post it makes it sounds like on a average coldish winters day heat pumps become useless and there is little point in having them. Even if that is not what you intended.