I've kept up with computer technology and hardware for about 10 years
but never built my own until February. I went into it whole hog - water cooling
and overclocking. It didn't take me long to start thinking about sub-ambient
cooling. Obviously, the main difficulty in cooling a processor is the fact that
150+ watts are being generated in area less than 1.5 sq inches ( high overclocks ).
Phase change gets the job done, but involves skills that I don't
possess ( I'm an electrician, not a HVAC guy ). So, I gravitated towards TECs.
I decided that the best results would come from building a liquid chiller
using multiple TECs. After deciding on my design, I found this part of the
forums, which has given me additional information .

Here is my design:

One 12" x 1.75" copper chamber mounted to the cold side of the
TECs that is part of the cooling loop of the processor.

Two 12" x 2" copper chambers mounted on the hot side of the
TECs and part of the cooling loop for the TECs.

Two PA 120.3 with Sanyo Denki fans to cool the TECs.

Blueline 30HD pump for the hotside loop.

PDD-20 pump (rebadged Iwaki MD 20) and 24volt power supply
for the coldside loop.

Two server PSUs for power

14 TEC1-12706 tecs

I was going to use 10 TECs in an attempt to get the best temps and stay
under 600 watts used, but right before assembly I decided to add 4 more
TECs ( I had enough room for them and enough power ).

Here are some pictures:



These are the copper bars I used. Four of the bars are 3/8" thick and two are
3/16" thick.



I used a hand-me-down Black&Decker router and a two flute spiral cut router bit to make the chambers.



I had some trouble at first keeping the depth consistent with that cheap router, but on average,
the dimensions of the middle chamber is 11.5" x 1.5" x 3/8"
deep, and for the outer chambers it's 11.5" x 1.5" x 3/16" deep.






To improve the heat transfer coefficient of my chiller, I inserted copper mesh in each chamber.



I applied silver-bearing solder paste on the inside of the chambers in order
to improve the heat flow into/out of the copper mesh.



I clamped each chamber and applied heat ( propane burner
and a thick aluminum griddle to act as a heat spreader )
and soldered the halves of the chambers together.
It was difficult ( little experience at soldering ) and not completely successful.



All three chambers have three 1/4" tubes on each end and with a 1/2" copper stubout soldered on each end.




Here is one of the chambers after some sanding ( I had to do much more sanding to get them flat enough ).
The gray stuff is JB weld, which is necessary
to seal the various leaks that appeared when I did a leak test.





This is a test run on the hotside loop to check out how much flow
it will have.




As you can see, the flow is a bit uneven between the two parts of the
loop. Also, the flow is a touch lower then I had hoped for ( I wanted
about 2.0 gallons a minute), but I think it will be enough. According
to Martin's test on the PA120.3 and with the fans I am going to use,
the air in / water out delta should be no more than 7 to 8 deg Celsius.




This the test run on the coldside loop. I used an apogee gt and an apogee
gtx to simulate, the best I could, a more restrictive block.



By adjusting the potentiometer on the Meanwell 24 volt power supply,
I could vary the flow rate from 1.29 gal/min to 1.72 gal/min.




Here are a couple of pictures of the chiller assembled. I had to figure out
how to sandwich the TECs and chambers together, and I had these
heatsinks that I got cheap off of eBay, so I decided to use them on
the hot side also. Using the info that Uncle Jimbo gave on how to apply
enough force to the TECs, I think that I have about 250 lbs per sq inch
on the TECs.

I still have several things to do. I have to mod my PSUs, construct my
open test bed, and eventually build a case for the chiller.

I will be testing this on a hot QX6700 (B3) and see how high of a stable
overclock I can get.