Comment on Heat-pump water heaters are a winner for the climate — and your wallet

• sunbeam60@lemmy.one ⁨11⁩ ⁨months⁩ ago

  In most places in Europe, hot water that’s been stored is treated with some suspicion. Besides, having a heating element is probably the least error prone thing you could make.

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• Mr_Blott@lemmy.world ⁨11⁩ ⁨months⁩ ago

  A lot more efficient

  Hundreds of engineers and scientists who designed modern dishwashers disagree with you

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  • Squizzy@lemmy.world ⁨11⁩ ⁨months⁩ ago

    I don’t think you understand how it works if you think there is an opportunity for disagreement here.

    It is more efficient to heat hot water to hotter water than it is to heat cold water to the hotter level. If I have a tank of hot water doing nothing why wouldn’t it be more efficient to use that instead of cold water?

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    • orrk@lemmy.world ⁨11⁩ ⁨months⁩ ago

      ya no, I think you might be the one overlooking something here, you talk about efficiency, but leave out the energy needed to heat the water to “hot Water” in the first place, all you did was split the work, and ignore everything leading up to the second work step.

      you are getting water from the tap, let’s say 10°C and need it heated to 70°C, it will always require the same amount of energy input (10°C->40°C->70°C is the same amount of energy as 10°C->70°c), but if you centrally heat part of it you will lose energy while you store it, and during transport.

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      • Squizzy@lemmy.world ⁨11⁩ ⁨months⁩ ago

        My air to water heater operates at 4.3:1 efficiency and heats to 60°. It stores it and loses 1° a day. The dishwasher would need to heat the water just 10° more given the tank is in daily usage.

        Otherwise the dishwasher would have to do it on in a faster timeframe. This is why electric power showers are more expensive to run than mains showers, they have to heat quicker which takes more energy.

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    • Mr_Blott@lemmy.world ⁨11⁩ ⁨months⁩ ago

      You misunderstand on-demand hot water

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• Zron@lemmy.world ⁨11⁩ ⁨months⁩ ago

  Do they not have mixing valves where you are?

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  • Squizzy@lemmy.world ⁨11⁩ ⁨months⁩ ago

    Genuinely for the longest time you’d only ever see mixer taps at a kitchen sink, they were not allowed anywhere else for fear of stagnant hot water contamination.

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• wax@lemmy.wtf ⁨11⁩ ⁨months⁩ ago

  That probably means that the hot water tank needs to be larger though. Guess it depends on the heating source though

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