Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: crimsonknight3 on 28/10/2016 00:36:06
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I have been looking around at various experiments and uses of peltier elements, and a question crossed my mind which I can't really find a good answer to....
Imagine, for a moment, that global warming/an asteroid impact/aliens cause the next ice age, would it be possible to use peltier plates to produce heat to keep a small room warm by alternating sides, so that the energy produced by one group of plates, powers another group of plates, and using the heat of the plate/body heat/other heating methods on the interior plates, continue the cycle? or would an interior temperate of say 22-24c not be hot enough to generate enough heat to be practical? In the ice age scenario, keeping one side cool will be extremely easy....
Thanks
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What you propose sounds a bit like a perpetual motion machine (...and these don't work).
Unfortunately, Peltier junctions are not very efficient - it uses about 4 times less energy to move the same amount of heat via a conventional reverse-cycle air conditioner.
I understand that one of the major efficiency limitations of Peltier junctions is that the active material is not very thermally conductive. But new materials are being investigated.
If you want to save energy, just insulate the room better. Then the heat of the humans inside will help keep the humans warm.
Of course, a well-designed heat exchanger will allow fresh air to enter, efficiently warmed by the exiting stale air.
See: https://en.wikipedia.org/wiki/Thermoelectric_cooling#Performance
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Heat pumps are sometimes used for heating, and peltiers are just heat pumps.
https://en.wikipedia.org/wiki/Air_source_heat_pumps