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I have a TEC-12706 thermoelectric peltier module. I am making a mini refrigerator (simple box refrigerator). I'm using this peltier and heatsink of equal size as compared with the peltier. I have given the picture of the heatsink attached with the hot side of the peltier. I'm facing a very big problem. While I connect this peltier with a DC source, it works properly for some time, i.e., the cold side of the peltier gets cool and the heatsink starts becoming hot. But just after a few time the peltier starts working in a different way. That is, the cold side of the peltier also gets some heated and the heatsink stops or reduces absorbing heat from the hot side of the peltier. I think the heatsink compound (or thermal paste) which I'm using is not proper. What do you think, what may be the problem? Please help me, I'm struck and am not able to make my refrigerator.!See this picture

enter image description here

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  • $\begingroup$ can some explain the down vote for this question. $\endgroup$ Aug 8, 2018 at 12:34
  • $\begingroup$ my bet is on the heatsink being too small $\endgroup$ Aug 8, 2018 at 14:41

2 Answers 2

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It is typical of a Peltier device to require an active method of dissipating the heat. You should have a fan on the hot-side capable of moving cooler air over the fins, in order to keep from destroying the device. The same aspect applies to the cold side. Use a fan to move cooled air to the desired location.

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  • $\begingroup$ Thanks for your answer a lot FRED DOT U. But I have one doubt, why should I attach a fan to the cold side. Please explain. $\endgroup$ Aug 8, 2018 at 16:27
  • $\begingroup$ The fan on the cold side will help to distribute the cooler air within the box refrigerator. It is possible to have the cold side to collect ice which will insulate it and prevent additional cooling. I have a commercially produced Peltier cooler which works in this manner. It provides a 40°F reduction from outside temperatures. $\endgroup$
    – fred_dot_u
    Aug 9, 2018 at 21:58
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Peltier modules are extremely inefficient and therefore need excessive heat dissipation. What you are experiencing is that the peltier module cannot dissipate all of the heat that it is moving (either from a heat load or from itself) and as a result it cannot maintain an appropriate delta-Temp.

I suggest adding a larger heat sink, a fan blowing over the heat sink (good 'ol convective cooling), or a water block.

See some options below: Fan: Click me! Water Block: Click me!

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  • $\begingroup$ What is the function of water block. Please explain. $\endgroup$ Aug 11, 2018 at 9:42
  • $\begingroup$ A water block acts similarly to a finned heat sink. With the water block attached to the hot side of the peltier, flowing water will use convective heat transfer to carry waste heat out of the system. The peltier is essentially a heat pump — the heat needs to go SOMEWHERE and if you aren’t able to remove it from the device, it won’t perform as it’s intended. TL:DR The water block will keep the TEC reference temperature relatively cool. $\endgroup$ Aug 11, 2018 at 20:42
  • $\begingroup$ Hey Vailbhav -- please +1 my response if it helped you with your problem. Thanks! $\endgroup$ Aug 13, 2018 at 16:26
  • $\begingroup$ Yeah I have voted +1 for your answer. $\endgroup$ Aug 15, 2018 at 0:46

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