Test community
cross-posted from: https://reddthat.com/post/20260613
Kettles are more efficient and thus faster at a given wattage.
The only reason a microwave would be faster is if you have low-wattage kettle or a 220v microwave, in which case it isn't an apples to apples comparison
I'm curious what would make a kettle more efficient than a microwave (or vice versa).
Having a stove element heating a pot of water, you lose a lot of energy around the sides. It's easy to see why that would be less efficient.
But a kettle and a microwave are only heating their contents. Why would one be more efficient than the other?
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
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.
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