• roofuskit@lemmy.world
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    2 days ago

    Is this really an article saying heat pumps are more efficient than resistive heaters? Yes, that is why heat pumps exist.

    The biggest issue is the battery itself. If it gets cold enough you can have difficulty even charging an EV outdoors. I would be a lot more concerned with whether or not my battery is well insulated and heated. Heat pumps are great and should be the default, but unless you’re going really far or have a very low range EV it’s not a huge issue.

    • GreyEyedGhost@lemmy.ca
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      1 day ago

      Yes, resistive heat is expensive, but that’s only part of what makes heat pumps in cars more effective. They don’t just heat your cabin, they heat your battery so you maintain range while it’s cold out. Here’s an article with more details and some pretty infographics.

    • Ulrich@feddit.org
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      2 days ago

      It defintely is a huge issue, considering resistive heaters use 3x as much energy. Most EVs have a “low range” and anything you can do increase it without adding more batteries and weight, especially in winter, is a huge advantage.

      • roofuskit@lemmy.world
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        2 days ago

        The lowest range EV in the US is 114 miles. The average commute is 52 miles. Most EVs sold in the US have a range of 250 miles or more. So a resistive heater eating 10% of your range is way less of an issue than your battery not charging properly in cold weather. Again, heat pumps should be available, but they aren’t going to save you if cold weather kills your battery.

        • rusticus@lemm.ee
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          8 hours ago

          if cold weather kills your battery

          Tell us you’ve never driven an EV, especially in cold weather, without telling us you’ve never driven sn EV in cold weather.

          Or maybe you should teach Norway how bad EVs are in cold weather, since over 90% of new car sales are EVs there.

          • roofuskit@lemmy.world
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            1 hour ago

            Tell us you didn’t read the entire context of the thread without telling us you didn’t read the entire context of the thread.

            Also, the fucking news for the last few years? There are EVs out there without enough cold protection for their batteries. Which is why, if you can drag your ego back up the thread, you’ll see that my original post said I would be more concerned with making sure my battery had those protections than a heat pump because the affect on range is much more drastic.

            You know, as the article in the post points out. EVs are not all the same.

    • bluGill@fedia.io
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      2 days ago

      You still need resistive heat as heatpumps don’t work below about -20C and those temperatures happen to at least some car buyers.

      • GissaMittJobb@lemmy.ml
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        2 days ago

        heatpumps don’t work below about -20C

        I don’t think that’s true? There are cold weather models that can work at COPs > 1.5 at -30C. Are we talking about a sizing constraint for the model here, perhaps?

        • foggenbooty@lemmy.world
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          2 days ago

          There are, but then I think you’d have problems with the effective rang of the AC in the summer. To my knowledge this is all about at what temperature the coolant is a liquid and when it’s a gas (because that’s how you exchange heat).

          A traditional AC only needs coolant that does this at summer temperatures. A heat pump tries to use one that will work at colder temperatures as well. A cold weather heat pump goes even further but I think there is a sacrifice in AC efficiency in the summer.

          Somone please correct me if I’m wrong. But I’m not sure if a do-it-all extreme cold and extreme hot heat pump exists, and as a car manufacturer you want to put in the one that will fit most cases, as opposed to a house which only needs to operate in the range of the climate it is built in.

          • Cocodapuf@lemmy.world
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            1 day ago

            It would make sense if the two stage heat pumps use different liquids in the different stages. I don’t actually know how these are made, so I can’t assert that this is how it works, but I would be surprised if it worked any other way.

      • HubertManne@moist.catsweat.com
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        2 days ago

        Im in one of those places but where im at its rare and at this point I will resist leaving the house pretty massively at those temps.

        • bluGill@fedia.io
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          2 days ago

          If it is rare enough and you don’t have an emergency that is the right thing. Odds are the rest of your city doesn’t have the ability to deal with those temperatures and so you going out will make things harder for emergency workers who must get out. If your city deals with this often then everyone will know how to deal with it and expect you to deal with it. You cannot shutdown your life for something that happens every single year, but if it is just a day or two every 5 years it isn’t worth being knowing how to deal with it other than the minimum emergency needs (that is make sure your HVAC system at home can handle it)

          • HubertManne@moist.catsweat.com
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            2 days ago

            I mean its more like we can go a winter without below zero F. Its a lot less common in the last decade and usually it does not last to long and that is really for lows. Highes below zero aren’t shockers but yeah we can go some years now without them and for most folks they are doing things while the sun is up. My thing is if I grab a metal doorknob with a bare hand and it is actually painful, then its like ef this im staying inside unless someone forces me out. Even back in the early aughts I had a job that was not wfh all the time like now but did it as needed and I could easily email I was wfh do to the weather being extreme. Its actually the wfh policy outside of all the time type one I like the best. wfh anytime there is a reason to and actually that place was like do not come in if you are sick. if you came in and coughed you would get the maybe you should have stayed home today comment.

    • MagicShel@lemmy.zip
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      2 days ago

      I know the resistive heater in my Volt can’t compare to the heat put out by the ICE. Often in the winter we’ll have to run the ICE to keep the cabin warm enough. It does have heated seats and wheel, but my wife is the type to set the heat to max until it gets too hot rather than just picking a temp and hitting auto to let the car manage it.

      If the heat pump can put out more heat for less energy, that would be a boon. That might be the second biggest issue (next to range) that has my wife vetoing an all-electric car. She gets the next vehicle, but I want the one after that to be a full EV.