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I'm sure I've read about this somewhere but I can't remember where and my Google search all seems to be too genetic to find what I'm looking for.

I'm looking for a component that uses electricity to move heat from one face to another (with the possibility of cold face to hot). I have a feeling it's piezo electric in nature but I'm not sure. I don't think it has any moving parts (ie. Not a fan), it's also not a heat pipe. Just a generic name for the type of device would be great. Thanks!

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    \$\begingroup\$ Peltier cooler? \$\endgroup\$ – 0xDBFB7 Dec 10 '16 at 3:03
  • \$\begingroup\$ It is not piezo electric, it is a peltier element. The first letter p was correct. ;-) \$\endgroup\$ – Uwe Dec 12 '16 at 16:57
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You are describing the "Thermoelectric Effect" popularly called the "Peltier Effect" and sometimes the "Seebeck effect". You can buy small arrays of diodes made up into a "Peltier Element" for reasonable prices.

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  • \$\begingroup\$ These elements transfer heat from the cold to the hot face, but due to their bad efficiency, the add a lot of heat in the transfer. That is why Peltier element pyramids are built for generating larger temperature differences. \$\endgroup\$ – Uwe Dec 12 '16 at 17:12
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The component you speak of is one you're familiar with, you definitely already have some. It's usually called wire, though this is just one convenient form. More generally, it's a component called a conductor. Metals are a good example.

If you run voltage through two dissimilar conductors of any kind that are in contact (creating a junction), then you are also pumping heat out of one conductor and into the other, and you can theoretically do this to cool one side of the two conductor junction to below ambient. This is a universal physical effect called the Peltier Effect. The peltier effect is really the same as the Seebeck Effect, only in reverse. If you introduce a temperature difference between two dissimilar metals and put them in contact (thus again forming a junction), then voltage will spontaneously appear across the two metals, and in proportion to the the temperature difference. That is the seebeck effect. If you do the reverse, and apply a voltage, then this will force heat out of one metal (cooling it) and into the other, only we usually call this the peltier effect.

Personally, I prefer the simpler umbrella term "thermoelectric effect".

This can be (and is) used as a convenient way to measure temperature gradiants (since this effect only cares about temperature difference, not absolute temperature), as well is generate minute amounts of power. It also varies with the two materials used, and temperature, so some clever maths can enable you to use this effect to measure absolute temperature (which is what thermocouples do) or even identify what type of metal or alloy something is simply by touching a probe to it. Pretty...ahem...cool huh?

You can even make a fairly effective (albeit low power) thermoelectric generator or thermopile at home simply by putting alternating bits of cooper and iron wire in series, making many junctions. Put one end in cold water, and heat the other, and you'll get current!

There are of course devices optimized to produce this effect which is what you were probably actually asking about.

Thermoelectric coolers aka peltier junctions are their name. You apply DC power, and one side will get hot, the other side will become cold, and it is using electrical power to pump heat out of one side and into the other. If you verse the polarity, the hot side is now the cool side and vice versa.

These devices are cheap and readily available, just google TEC or peltier, or check eBay, and you should find a plethora of devices you could experiment with, and some significant wattage will only cost you a few dollars.

Just be aware that they really only work well in a very narrow window of ideal operating conditions, and generally you should expect performance far inferior to things like phase change coolers (your fridge/freezer, AC etc). They do have the advantage of being small, inexpensive, and solid state however.

Anyway, you can read all about this neat and quite useful phenomenon here: https://en.m.wikipedia.org/wiki/Thermoelectric_effect

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