Originally posted by: Luckyboy1
I cool with a Peltier and as already stated, trying to cool with a Peltier on air is in most cases, just about useless due to the inability of even the best of air cooling to carry the heat generated by the Peltier fast enough. As a result, and believe it or not, this is the good news, good quality water cooling will take you about 80% as far as you can go with current cooling technologies. Add Peltiers done right that is to the mix and you get to about 90% as far as you can go. Go to compressed gas cooling and you can add maybe another 6-8% to that and for the last 2% you want to submerge everything in liquid nitrogen!
Then you need to consider what CPU and GPU you will be cooling with a Peltier and get a Peltier big enough to do you some good. For most modern CPU's that would be a 220 watt or bigger Peltier and for the GPU, a 170 watt or bigger GPU and they run on 12 volts DC. Let's see here... 220 + 170 / 12 = almost 33 amps on the 12 volts rails and you'd still need more power by at least 6 more amps to run the water pump and cooling fans for the radiators. You noticed I said radiators and not radiator. You would want to run a double looped system and have a pump big enough to push it all along.
Lucky, what the hell are you talking about? Most radiators can remove several kW [Yes, KW.] of heat. As the water gets hotter, heat becomes even easier to remove.
The temperature of the water is important [see below], but a double heatercore radiator with 2 38mm fans @ 7V can take car of quite a bit
Also, remember you're running these on 12V, and peltiers NORMALLY RUN ON HIGHER VOLTAGES. [Hence the undervolting charts at XS

]
If you run a 226 Pelt @ 12V, it'll draw 18.94A. Cooling capacity? 140W.
320 Pelt @ 12V draws an 22.3A..235W cooling capacity.
So...
With the 226 Pelt, it's Dt=(1-[110/140])*69=14.78C
So, you'll have a ~15C difference between the hot and cold side. If you can keep the water at
Now...
With the 320 pelt..
Dt=(1-[110/235])*69=36.70.
Wowsers, eh?
So, your best bet is to buy TWO 320Watt Pelts, buy a PSU with a VERY large amount of amperage on the 12V rail [read: Well over 40A....a 46A PSU might even be insufficient.

.]... oh, and watch your electricity bill skyrocket.
Most would think 'Oh, if you can afford another 120 dollars for a power supply and the 60 you'll shell out for the peltiers, on top of the money for the insulation and cold plates... I don't think Half a kilowatt hour will do you much harm.'
But, for those who care:
$0.10 kw/hr on the high end... half a kw/hr per hour, so 12Kw/hrs.. assuming 500W [Actually a bit more, because efficiency will only be around ~70%], you pay anywhere from 1.20->2 bucks a day.
Over a year, 700 dollars. Not cheap. Costs just as much to cool these as running your entire computer at full load 24/7. Keep that in mind when looking into peltiers.
Just though I'd point that out.
--Trevor