this post was submitted on 17 Feb 2024
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Showerthoughts

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A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. The most popular seem to be lighthearted, clever little truths, hidden in daily life.

Here are some examples to inspire your own showerthoughts: 1

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If you made it this far, showerthoughts is accepting new mods. This community is generally tame so its not a lot of work, but having a few more mods would help reports get addressed a little sooner.

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If a machine is never 100% efficient transforming energy into work because part of the energy is converted into heat, does it mean an electric heater is 100% efficient? @[email protected]

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[–] [email protected] 54 points 11 months ago* (last edited 11 months ago) (3 children)

Technically, yes. Even the internal resistances outside of the heating elements eventually radiate into the space. Since the purpose is space heating, it's not a waste product and they can be roughly considered 100% efficient.

The reason heat pumps are more efficient (i.e. around 300% or more) is not that they create more heat from the same amount of energy but because they concentrate and move existing heat from one source to another.

[–] [email protected] 15 points 11 months ago (1 children)

This is correct, but it's also, it's only 100% of the heat at that point in the circuit.

Technically, using natural gas to make electricity, then sending that electricity to an electric heater would be less efficient than burning that natural gas for heat at the source.

So it depends on where you start counting from.

[–] [email protected] 14 points 11 months ago

True, and also the transmission losses between the power plant and your outlets are also factors. I just treated the question like a high school physics one where you're allowed to disregard air resistance. lol

[–] trolololol 1 points 11 months ago

If so that means moving a block of ice has negative heat efficiency. Sounds like nitpicking to me.