Heat pumps can’t take the cold? Nordics debunk the myth::By installing a heat pump in his house in the hills of Oslo, Oyvind Solstad killed three birds with one stone, improving his comfort, finances and climate footprint.

  • onlinepersona@programming.dev
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    1 year ago

    It never ceases to amaze me how people don’t read past the title 🤦 There are people debating about -10 to -30C when the article clearly states that it works in those temperatures. Not only does it work, it’s twice as efficient as electrical heating at those temperatures.

    • Zeshade@lemmy.world
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      1 year ago

      I think it does, and it seems to work because of a defrosting feature that earlier models didn’t have. But I wouldn’t say it does so very clearly. Unless I missed it.

      • NotSoCoolWhip@lemmy.world
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        1 year ago

        Electric heat is not always 99.9% efficient, resistive heating is.

        Heat pumps are more than 100% efficient(compared to resistive heating)

        It’s not bs, because we are moving heat, not creating it. You thinking it is bullshit will not change the laws of thermodynamics. Try to think about it this way.

        “Cold” is a made up human concept, it really is a lack of heat energy. The coldest is 0K, but even a Midwest winter is waaaaaay above that. Heat pumps (and all refrigerant-based systems) work by changing the phase of the refrigerant from liquid to gas to cool, or by compressing a gas to a liquid. This phase change takes energy from the surrounding air (think about computer duster, the can gets cold) and then pipes it inside, where it can be compressed to release the heat it just picked up from outside. In the summer you flip the reverse switch to cool your house.

        Here is an explanation from someone much more eloquent than myself:https://youtu.be/7J52mDjZzto?si=sYlNlpvGnJs16lwk

      • Kazumara@feddit.de
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        1 year ago

        I just don’t buy this twice as efficient bullshit.

        Do you understand how heat pumps work? The heat you’re drawing on is the the heat of the outside compartment on the outside, therefore the heat moved to the inside can be more than just the heat equivalent of the electric energy you put in. That’s how these achieve more than 100% efficiency, in general. In fact if the outside isn’t so cold outside they can achieve 300%-500%.

        Now the trick to moving heat from a cold outside compartment to a warmer inside compartment lies in the compression. If you draw even a moderate amount of heat energy into your medium, then compress it, it will turn quite hot allowing you to dump heat into your warm inside compartment. Then as the medium flows out you let it expand and it turns really cold, cold enough that it can draw in heat from the cold outside. But the lower the difference in temperature of the outside air to your expanded medium gets the less heat you can transport per unit of time, that’s why we’re only looking at 200% here.

        • T156@lemmy.world
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          1 year ago

          You also have the waste heat being converted into useful heat, which only helps the efficiency. A standard resistive heater is almost all waste heat, so if you can use some of that energy to get more heat from elsewhere, that’s how you can get 100%+ heat efficiency.

      • Cethin@lemmy.zip
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        1 year ago

        So you’d rather trust your feelings? Just loon into it if you’re that skeptical.

      • justJanne@startrek.website
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        1 year ago

        “at those temperatures”

        well, to a heat pump even -40° is still 230K, which is plenty of energy to move around and work with. It may be cold to you, but to a heat pump it’s not.

  • Overzeetop@lemmy.world
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    1 year ago

    Good Lord - $2600 for a whole house system? I think that’s what my local (mid-Atlantic US) HVAC shop is getting for a single-room mini-split.

    Wait until people find out about ground-source heat pumps and water heater heat pumps. What you get out of those is more consistent year round, too. It’s almost like leveraging technology has benefits over just burning carbon and hydrogen to make heat.

    • happyhippo@feddit.it
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      1 year ago

      2600 is dirt cheap even by Euro standards, trust me.

      Here in Italy a single room split would cost you around 1k to 2.5-3k depending on the brand.

      A whole house system you’re probably looking at 10k and then some.

    • douglasg14b@lemmy.world
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      1 year ago

      I got a quote in rural America for a single room minisplit, $10,300.

      Absolutely bonkers.

      • Dozzi92@lemmy.world
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        1 year ago

        That is absolutely bonkers. I put one in myself for my one room garage that I converted to a place to hang. Cost 720$ after tax for a Pioneer mini split. It’s entering its third year in use and I love it. That being said, I wouldn’t be so risky as to put my own in when its task was heating or cooling my home. Just my garage is my problem, the rest is my family, and so I paid. But I got a whole home solution, two floors, Carrier units, for about $15k.

        I believe what you’re looking for is out there and not ridiculous price.

      • Calavera@lemm.ee
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        1 year ago

        The guy you quoted just want to make his monthly paycheck on you alone, because that’s way over anything reasonable

      • NotSoCoolWhip@lemmy.world
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        1 year ago

        Also in rural America. How did you get someone not to laugh at you when you asked? God I fucking hate the small mindedness around me, but I couldn’t stand the city either. I cannot find someone to put one in my house so I’m going to have to install it myself next summer.

    • ikidd@lemmy.world
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      1 year ago

      $2600 is utter bullshit. I had several quotes for a 1000sf house, not a single one was under 16000 installed, after rebates. My payback period was going to be almost 20 years even against a medium efficiency gas furnace.

      • timbuck2themoon@sh.itjust.works
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        1 year ago

        And this is why the comments here miss the point- sure, heat pumps nowadays can work that low but in a lot of places the payoff period is well outside what anyone is looking at.

      • Nobsi@feddit.de
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        1 year ago

        You’re just repeating what all the gas installers keeep repeating so they don’t lose business.
        Every House built after 1990 or houses that have had insulation makovers in the past 20 years are perfectly fine to heat with a heatpump.

    • Avg@lemm.ee
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      1 year ago

      Half of my house was 8k, the other side I’m planning to install myself because I don’t have that kind of money just waiting to be spent anymore.

    • kameecoding@lemmy.world
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      1 year ago

      I don’t think Geothermal makes much sense unless you live in one of the extremes, mainly the cold one, For example I an from Slovakia and I don’t think the temperature here went under -20C in the last few years, I barely remember any days going under - 10C, so you would be paying quite a premium for a geothermal heat pump for rather marginal gains, it would certainly need quite a good analysis if the difference in performance would ever pay for the price difference, especially with better insulation and heat recuperation systems becoming mandatory.

      There are also things like heat pump based driers now on the market btw.

      • Overzeetop@lemmy.world
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        1 year ago

        I suspect it’s mostly a function of mass availability. Even here in the states ground source heatpumps are rare, even though the systems are more reliable (since there is no equipment exposed to weather) and a shallow borehole isn’t excessively expensive.

        I’d forgotten about heat pump clothes dryers. Those are fascinating, and really interesting for older buildings or locations without close access to exterior venting.

      • barsoap@lemm.ee
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        1 year ago

        Shallow geothermal is basically dead in most of the world because it’s too much hit and miss, the geology is simply too complex and involved (and underground) to predict. There’s also a fuckton of issues with water ingress, minerals that like to expand when getting wet and such. You can’t really take Iceland as an example for countries not straddling a continental rift.

        Deep geothermal is utterly reliable but for the longest time drilling that deep was just too expensive. Plasma deep drilling is a solution but it’s still in its infancy.

    • tony@lemmy.hoyle.me.uk
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      1 year ago

      Yeah similar in the UK. £3k for a single room mini split. £6k for a two room, etc. There’s no way you’re doing a whole house for less than bend-over money.

    • regbin_@lemmy.world
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      1 year ago

      Wow that’s really pricey. Here in Malaysia a 2 HP mini split with inverter costs roughly RM 2400 including installation (around $500).

      Granted the average salary here is much lower but it’s amazing how much the prices differ given that they all basically come from the same factory.

  • Pogbom@lemmy.world
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    1 year ago

    Hell yeah, we’ve got a heat pump and we’re in Canada where it can get to -40°C (which is coincidentally also -40°F) and that thing works like a beast. Fortunately we also have the cheapest electricity in North America so the decision was easy.

    • Chetzemoka@startrek.website
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      1 year ago

      Electricity monopoly in the US = they can price gouge, and this is literally the only reason I installed a dual fuel system with a less efficient heat pump. The Eversource electricity price hikes last year probably would have meant I couldn’t afford to heat my home in the worst parts of winter here in Massachusetts.

      This is how policies are killing the planet. Socialize electric utilities, upgrade the electric grid, subsidize the use of electric heat pumps so they’re actually affordable for all end users, and of course more people would adopt them.

      As it is, I run my heat pump as much as I can, which is like 9 months a year. Better than only having gas heat at least.

      • Earthwormjim91@lemmy.world
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        1 year ago

        The US has some of the lowest electricity prices in the world though. Only a couple pennies per kWh higher than Canada. And MUCH lower than pretty much all of Europe.

        In 2020 (last year I could find from Canada specifically) Canada averaged 11.25¢ per kWh. The US averaged 13.04¢. The UK averaged 21.91¢, France averaged 19.91¢, Finland 20.56¢, Spain 28.77¢, and Germany 33.39¢.

        https://www.electricity.ca/knowledge-centre/the-grid/customer/electricity-rates/

        It’s more that Canada uses a LOT of hydro power which is cheap.

        • Chetzemoka@startrek.website
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          1 year ago

          This is the problem I’m facing though:

          https://www.wbur.org/news/2022/11/18/eversource-western-massachusetts-electricity-rates-hike-2022-2023-winter

          Our electric rates went from 18¢ to 25¢ last winter with no warning. It’s not that our prices are particularly high for now, but rather that they’re unreliable. I didn’t feel secure installing an electric only system because of this, even though I could have gotten a more efficient system. The dual fuel allows me to toggle between the two as needed, which feels like the safer option for the next 15-30 years that I expect to have this thing.

          Sucks because I’d really prefer to have one of those Mitsubishi hyperheat systems. But even with the less efficient system, I’m running in heat pump only mode in the to 0⁰C nights we’re seeing right now and it’s fine.

          • pedalmore@lemmy.world
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            1 year ago

            You made the most sensible choice and are dramatically reducing you gas use, so you should feel good about that! I have a new Mitsu hyper heat (Colorado here), but recognize it wasn’t the most cost effective system and ultimately just really wanted it. It’s bonkers how well it work though. We’ve only hit 10F this last weekend but it didn’t skip a beat. Looking forward to -10F. For most people, keeping a gas furnace for a few weeks a year, and using a smaller heat pump than you would spec if only using a HP makes a lot of sense. You’re not missing much (and some would argue that peak winter demand in an electrifying world is a big problem that has backup gives us more time to solve anyway).

            • Chetzemoka@startrek.website
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              1 year ago

              Yeah, you did exactly what I wanted to do haha. I just love the Mitsu products so much. I had Mitsu mini-splits when I lived down in the Caribbean, and I’m a complete convert. I did install a supplemental Mitsu mini-split in the largest room in my house, which actually is so god damned efficient, it reduces the load on the central heat pump. The two combined get me through a really reasonable portion of the year. Those things are just amazing.

    • ikidd@lemmy.world
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      1 year ago

      What’s your heat pump? I’ve been looking into them and I can’t find one that’s willing to say it works past about -15.

      • bbbbb@lemmy.world
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        1 year ago

        The Mitsubishi Hyper heat can work down to -13F, The absolutely best resource I’ve found for heat pump research is the NEEP database which will you give you actual BTU outputs at various ambient temperature readings: https://ashp.neep.org/#!/product_list/
         Also worth considering a geothermal heat pump depending on your geography, as then you have a guarantee of efficiency all year round

        • pedalmore@lemmy.world
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          Second the NEEP database. I’d just add that the lowest temps listed here aren’t the actual equipment minimums - each model has a cutoff temp where it will literally shit the bed (except ground source of course). For my mistu hyper heat, it’s -26F. Capacity will keep dropping after -13F though (where it’s still at like 80% I think).

    • SendMePhotos@lemmy.world
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      1 year ago

      Can you just start saying “America” that way it includes south America and Central America, also?

      • QueriesQueried@sh.itjust.works
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        1 year ago

        When the context is involving climate, electricity rates, and money, there is little overlap between all of the Americas. It makes sense to tighten it down to the top half (more similar climates, etc) or bottom half (electricity rates for example). Canada has the wealth and the electricity rates to make heat pumps extremely viable, and for the most part climate too. The USA shares a lot of this. The Central/South Americas do not overlap like this with Canada.

      • Pogbom@lemmy.world
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        1 year ago

        But that wouldn’t be accurate because there are South American countries with even cheaper electricity than here, so it’s only the cheapest in North America.

        Also not to be too pedantic but central America isn’t technically a continent, and it all falls under North America anyways.

  • Magister@lemmy.world
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    It depends on the model (and the price), I’m in Québec where we have -30°C (-22F) about every winter, my heatpump is mid-range, and works fine until -20C (-4F) so 95% of the time. It is set to 23C (73F) and it’s between 21-23 everywhere in the house. The electric baseboard are set to 21C (70F) as backup.

    So yeah, heat pumps can works great in winter, no problem.

    Also as written in the article, with defrosting and variable speed compressors, it is very efficient. Mine is Energy Star compliant, and act as air conditionner in summer.

    • NightAuthor@lemmy.world
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      1 year ago

      Makes sense to me that they could theoretically work all the way down to near 0 kelvin, just depends on their efficiency. Just so long as there is heat to be had…

      Also, not sure energy star really means much.

      • applebusch@lemmy.world
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        1 year ago

        They theoretically could, but the coefficient of performance would go below 1 long before you get close to zero Kelvin. That means it would cost more energy to pump the heat than is pumped, so you’d be better off using an electric heater.

        • KairuByte@lemmy.dbzer0.com
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          Not to mention, you’d need a material to pump. R-32 which I believe is the most common at the moment, has a freezing temp of -132, meaning it would be useless at temps near 1K.

        • NightAuthor@lemmy.world
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          Ah yes… that’s a very good point. I’m not about to learn a bunch of chemistry and physics and stuff… but I’d be interested in reading about this theoretical optimization if electricity was free, there was no gravity, friction was 0, etc etc etc.

  • Obinice@lemmy.world
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    1 year ago

    How is this a myth? Nobody with more than two braincells thinks that heat pump heaters don’t work in the cold.

    If we start comparing everything that idiots think to a mythological mystery worthy of note, we’ll be here for an eternity.

    • Buffalox@lemmy.world
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      This is not a myth but a fact, heat pumps don’t work at extreme cold temperatures.
      What temperature exactly depends on the coolant used.

      The efficiency also degrades at lower temperatures.

      This is a random example of first hit I got on a heat pump.
      https://heatnow.dk/produkt/altech-sirius-9-varmepumpe/

      Notice the effect drops dramatically below -20 C°.

      But this is a pump sold for the Scandinavian market, therefore it is of course designed to work at low temperatures. It doesn’t state the minimum, but I’m guessing it would be around -40 C°. Which is very good compared top older models.

      • AA5B@lemmy.world
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        1 year ago

        But that’s not sufficient. As the temperature gets colder, it’s not just less efficient but produces much less heat. At the lower temperatures, it may not be able to keep up. Since it would be wasteful most of the year, heat pumps aren’t sized for that

        • Buffalox@lemmy.world
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          IDK why you are downvoted, this is exactly true. The pump can only use it’s max power, and at max efficiency it generates 4-5 times that power in heat. But at temperatures below what the coolant allow, it only produce heat equivalent to the power put in, or a 4th to a 5th it’s max output.

          Meaning the pump gets less efficient as it gets colder, and potentially will not be able to keep up in extreme conditions. As output goes down at lower temperatures, the same time demand for more heat increases.

          The Heat pump shown however, does go very low, and it would be exceptional if the limit was reached. But just a decade ago, most heat pumps couldn’t go nearly that low, and lost efficiency quickly already below zero Celsius.

          Despite that, the advantages with the newer heat pumps are still big enough for it to make good sense to switch to it for most, even Scandinavians.

          • AA5B@lemmy.world
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            1 year ago

            Here in New England as far as I can tell, HVAC contractors tend to recommend hybrid systems, with a gas furnace as the secondary heat. However maybe that’s because gas is much cheaper than electricity.

            Maybe there’s a contractor around who can give a better opinion on whether my experience is general

            • Buffalox@lemmy.world
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              1 year ago

              I never heard about that, here it’s very extreme if it’s below -20 C°, and new heat pumps can handle that, and remain pretty efficient.
              I think the consensus here is to get rid of the gas. Despite we have it from the Nordsea, but the price structure is 100% dependent on the situation in Europe as a whole.
              And Russia has fucked that up. So I don’t think anybody here is recommending gas for that reason. Although gas has already returned to be the cheapest option even here AFAIK, and prices have stabilized in part due to LNG from USA.

      • whoisearth@lemmy.ca
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        1 year ago

        How much did it cost and what rebates are available? I’d love to say fuck Enbridge.

          • whoisearth@lemmy.ca
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            Damn that ain’t cheap. What’s the expected savings per year in reduced gas/hydro?

            Edit - how quick is it expected to pay itself off

            • PizzasDontWearCapes@sh.itjust.works
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              I’m not sure, likely somewhere between 5-7 years.

              We wouldn’t have done it if our furnace wasn’t shot. As a plus our A/C leaked it’s freon in the winter, so replacing it was an improvement as well.

          • Sparlock@lemmy.world
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            1 year ago

            You could have gotten a whole home mini split from senville for less and it works down to -30. My heatpump from 15 years ago only did down to -10.

            I found all the HVAC guys in my area were still really pushing the heatpump and furnace combo because that’s what they knew and not what was best, cheapest or most efficient.

            • PizzasDontWearCapes@sh.itjust.works
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              How does a mini split system work? Does it plumb into traditional ducting?

              Edit: just looked them up. Also found out that a friend out East with an older, oil heater house (no central ducting) was quoted a mini split for their place at over $20K

              Our place is a four bedroom, two storey with a basement. I wonder if a mini split with the requisite air handlers would be cheaper

              On a side note, we have a West facing room with large windows that I have to run a portable AC and space heater in as it’s temp is always extreme vs the rest of the house. A mini split just for that room would be great

              • Sparlock@lemmy.world
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                They are honestly pretty easy to install if you are at all handy. The smaller ones (like for a room) have minimal electrical needs and are something you could get an electrician buddy to do for a case of beer if you buy the parts off amazon. Depending on the brand they are varying levels of DIY but nothing a 5 min youtube video can’t teach you. All in for my house it was 6k and a saturday afternoon to get it done.

                • PizzasDontWearCapes@sh.itjust.works
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                  1 year ago

                  How many mini split heat pumps and air exchangers did you put into your place

                  Overall, we should be net $5K with an installer because of rebates, but it’s good to know cheaper alternatives are available

    • Iamdanno@lemmynsfw.com
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      It’s not that people think they don’t work in the cold, it’s that they are less suited for the areas or days of extreme cold.

      • OminousOrange@lemmy.ca
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        1 year ago

        Which is why you have a backup system. I have a net zero house in Saskatchewan, Canada. My Carrier heat pump will operate to -15C, and switches to electric heating coils in the air handler if it’s colder outside. It’s a rather extreme climate here, but in most other places, you’d be fine with some baseboard heaters as backup.