220w peltier help needed
 

Im getting pretty close to assembling my first water/pelt cooled rig and i had bought a 220w pelt a while back. The site I got it from seems to have changed and they dont sell peltiers with this high of watts anymore. I am definitely getting a dedicated power supply for it (duh) and I was cruising over a few power supply manuals and some of the higher end Antec PSUs can get to 20 to 24 amps on the +12v line. And with the 550w Enermax PSUs maximum current rating at 36amps. I keep reading that its better to under-volt pelts, not sure why though. So....can I get a recommendation for powering my pelt? And is running it at 12v too low if it requires 15v or so?

Thanks in advance!

The reason people get optimal cooling at a voltage below the pelts maximum, (Vmax) is that the power consumption of the pelt goes up roughly as the square of the input voltage. At about 75% of Vmax, you are getting 90% of the pelt's heat pumping capacity. (Q)

Running the pelt at Vmax instead of 75% of Vmax means putting 78% more power into the pelt to get 10% more cooling.

That extra 78% power consumption has to be cooled by the hot side cooling system. The hotside cooling system (and thus the hot side of the pelt) is going to get hotter because of the increased power input. Even though you get a slightly higher deltaT across the pelt at Vmax than at 75% of Vmax, most hotside cooling systems will allow the hotside temperature to increase such that the additional deltaT is cancelled out or worse.

I've attached a crude paint drawing that gives a rough idea of these issues.

Edit: Don't take these curves too seriously. The power consumption curve should be exponential, and the cooling capacity curve should be parabolic. I was too lazy to generate accurate curves with excel.

thank you very much for the explaination since87. i have seen the light :D

I was told that for a 220w TEC, 13.6v tends to be about optimum... so that's what I'm running mine at... using a Meanwell s320-12 PSU