• bjorney
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    3 days ago

    Microwaves don’t generate heat directly, they produce ionizing radiation, only some of which gets absorbed by the thing you are heating. Energy is also lost as heat in the coils, and from spinning the plate. Microwaves are only between 50-75% efficient

    • Dave@lemmy.nz
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      3 days ago

      Wouldn’t there be an argument for a kettle, where as you heat it some heat (including steam) is lost through the top? The microwave has an enclosed cavity that captures this loss and so reduces future loss as the water heats.

      Also, the kettle heats a certain quantity water of which only some is used. A mug in the microwave would heat only the water you use.

      • bjorney
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        2 days ago

        Wouldn’t there be an argument for a kettle, where as you heat it some heat (including steam) is lost through the top?

        Yes, but evaporative cooling happens in a microwave too.

        The microwave has an enclosed cavity that captures this loss and so reduces future loss as the water heats.

        Microwaves don’t have an airtight seal. If they did you would be able to blow the door off if you heated a large enough bowl of water.

        Also, the kettle heats a certain quantity water of which only some is used. A mug in the microwave would heat only the water you use.

        You don’t have to fill kettles up to the top to use them