I'm sure this will **** somebody off...

[cdrikari]

Let me lay out the situation and then we can get to the meat of it. This will be on the semi-long side, for which I apologize in advance.

Here is the current cooling system:
Lian-Li PC-60 with all the 80mm fans replaced with 39CFM Sunons, Eheim 1048 pump, 1/4" ID PVC tubing, and the radiator and water block from a AquaCool system that I bought awhile ago to make my break into watercool (relatively) painless. It worked. I had been running a PAL6035 w/ the BlackLabel and a day after the water system went in I (and my wife) fell in love with it. This rig cools a AHYJA 1.4 T-bird.

To feed my addiction, I have been looking to upgrade the water cooling system for awhile and went out and found a roomier case (Antec SX1200) that at $50 I won't mind hacking into like I would the Lian-Li. I ordered a Maze 2 from Danger Den and started thinking about radiators. My own thoughts lead me in the direction of Heater cores, though for mountability I am considering the Hayden 676/7.

However, I ended up at Overclock-Watercools site looking at the Black Ice series and it led me to the "Radiator Performance" page at OCWC http://www.data-detective.com/overclock/rad_perf.html
I stared at this page for a long time. As a grad student I TA Thermodynamics and my brain started screaming at me. I don't believe their numbers. Back of the envelope calcs confirm this, making some pretty wide assumptions on materials and construction. Specifically, I don't think that the degree of differential is possible, nevermind the fact that there is no proof, no citations, no mention of method by which the numbers were reached. This is problematic, since I realize that engineering is a highly empirical science, so tests are always the way to go if you can.

Can anyone comment on their figures? I'm not saying that it is necessarily impossible, it just sets off my Sesame Street-o-meter. "One of these things is not like the other..." Specifically, anyone who has for instance, run a BI2 and maybe a heater core on the same system. I've read most of the articles here and everywhere else I could find.

Thanks in advance.

[RoadWarrior]

Those figures look okay to me, but impressive as they are, they don't of course mean that they'll necessarily do all that in your particular set up. I'm going on the empirical experience that car heater cores are about twice the size of most of those coolers, and the heat output from a car heater is about equivalent to a 1200-1500W household electrical fan heater, so those figures seem believeable.

Now, it doesn't mean it will take more than 80W out of your CPU, it merely means that given the ideal flow rates and thermal interfaces at the hot end, that you could cool several CPUs and get the same degree or two above ambient cooling, and the core could dump all that heat. It become relevant of course if you start thinking about stacking up 150W peltiers, then you need to match your CPU output plus your peltier stack output, and those figures will start to get real important when you have that much power to dissipate.

So, I guess the way you are probably thinking is, that somehow these figures should mean that CPUs should get cooler than ambient. Well, of course not, not without a heat pump to actively extract more than the 80W that a CPU might nominally put out. Once you've got it in the system, they can dump it, but it'll only get rid of what you give it.
regards,

Road Warrior

[RoadWarrior]

Oh, maybe you were also calculating the theoretical performance as convective output, well, those babies were never designed to convect much, it's all forced air, so some assumptions about airflow have to be made, like they all get 40 cuft/min through them or something.. For equivalent convective performance we'd be looking at something rather different, I'd guess a hotwater central heating system would be a good example, a radiator from one, designed for convective output. I guess to get 3000 BTU or so out of one of them you'd be looking at something like a 3ftx3ft double layered unit.

regards,

Road Warrior