I am designing a 9u rack server with optical ports. I want to implement Thermo Electric Cooler(TEC) for cooling the ICs(switches, FPGAs) on board, so that I can reduce the fan speeds. Is this a good idea, if yes suggest some TEC modules.
1 Answer
TECs aren't magic: they don't destroy heat. That would be a violation of conservation of energy.
All they do is pump heat from one side of its plates to the other while using some energy. When you make one side cool, you still need to cool off the other side of the plate. The other side of the plate will probably get pretty hot, more hotter than the CPU alone.
TECs aren't very good for constant thermal loads, so you're probably not gonna go anywhere with this setup. I don't have any numbers to back this up, but you're probably going to see a tiny decrease of temperature in the CPU while your heatsink gets way way hotter. Not a great idea if you're trying to reduce fan speeds.
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\$\begingroup\$ Thanks, I need to control the fan to meet the acoustics. Then I will try controlling the fan according to the heat in the device. \$\endgroup\$– pavanCommented May 22, 2018 at 6:25
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1\$\begingroup\$ Well theoretically heatsinks transfer more heat if the difference with the ambient temperature is larger. So less airflow would be required. However, the TEC moves less heat the greater the difference becomes between the plates, using more power. Thus with the loss of the TEC itself, and it's (significant) power supply, it's probably still not viable. \$\endgroup\$– Jeroen3Commented May 22, 2018 at 6:26
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3\$\begingroup\$ "I don't have any numbers to back this up but you're probably going to see a tiny decrease of temperature" ... it's potentially worse than that: for some setups, the peltier cooler actually makes the cold side warmer, because the amount of power dissipated in the cooler is actually a significant contributor to the net power dissipation of the whole system. This article has a good analysis of the situations where that can happen, and gives guidelines for when a peltier cooler is beneficial and when it isn't. \$\endgroup\$– JulesCommented May 22, 2018 at 9:39