killer byte

I'm thinking of getting a 226W peltier to cool a cpu, hopefully to negative temperatures. i will take the necessary precautions to prevent condensation. I was just wondering, running it at the max voltage, will the peltier be constantly gobbling up 226W? because i have my suspicions that when you first start the computer up it will consume 226W but after a few minutes it will be "warmed up" (well, not warmed up but just sort of settled to a steady state) and it will consume less power.
i was thinking this because a resistor has higher resistance after it has been running for a while and is heated up because heat increases it's resistance. Is this the same with a peltier? I mean, once the temperature difference reaches T MAX after a few minutes, will it consume less power?
does anyone know a bit about peltiers who can confirm this?

ChielScape

at the max voltage, it will continuously consume 300+W of electricity, moving up to 226W of heat.
im not much of a peltier guy, so i cant go into it as deeply as you may want.

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mrkryz

Each 226W pelt consumes about 350W when run at full power in real world applications. That means you should *really* have a stable and high quality power supply to not run into problems. A dedicated PSU will prove much more prudent then trying to tax an existing psu (unless you've accounted for all consumption in your machine under load)

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killer byte

ok then, it's just running an extra 300w+ will add a bit to the power bill
i will get a separate power supply for it, maybe about 300w if I'm running it at 12v?
I want to air cool it as I don't have the budget for water cooling, I know that i will need a beast of a fan for this, i'm getting one with 0.17C/watt.
this will be cooling an intel pentium D 925 dual core 3.0Ghz http://www.aria.co.uk/Products/Compo...roductId=29012
anyone have any idea what kid of wattage of heat this cpu will produce?
given the wattage of the cpu and peltier, the thermal resistance of the fan, the T MAX of the peltier etc how do i work out what kind of temperature this will cool the cpu to?

The_Rocker

Get a good 420 / 500 watt PSU for it because you want a PSU which can handle it comfortably.

A 300w PSU will be stressing its nuts off.

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CPU's in past 18 months: Pentium D 925, Q6600 B3, Q6600 B3, Q6700 G0

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mrkryz

http://www.3dcool.com/PWC.php
http://www.benchtest.com/calc.html


Should help with ballpark numbers and I think your chip has a TDP of 95W? Are you overclocking?

So add 95W & add +20W (sanity check) + 350W TEC = 105W + 350W = 455W heat load

Yes I overestimated just to be safe.

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mrkryz

And as TheRocker suggested .. a 2nd 500W PSU will serve you well... and leave room for when you decide to go to a 437W TEC lol The draw will be split between the CPU (105W from existing PSU) and all the TEC and fans you need (off hopefully a single rail psu)

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ChielScape

the 437W is a 24v unit, and can consume over 600W.
you could do a 320W with the 500W PSU though.

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Bigger = better, except for transistor size.
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Ultrasonic2 (muffy)

i think this is isn't going to work .. you'll need a way better cooler than a small air cooler to cool your TEC .. and even with a great watercooler you'll be lucky to get a loaded temp below 0

oh and a 226 TEC will consume 454watts of electricty moving 105 watts with theTh temp of 20c

mrkryz

Man ... Im off by one degree on my ballpark estimate of 455W ... Geeeeze cut a guy some slack doing the math in his head LOL

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