SUMMARY: Recycling heatsinks into a plastic-enclosed waterblock will perform as well as drilled copper blocks.
Overclock-Watercool sent us a couple of blocks to test out; one copper block with a lot of channels and a conventional heatsink enclosed in a plastic block (the one pictured below is a prototype). When Chip Eckert first told me about what he was doing, my immediate reaction was “Plastic will melt or deform.” Well, as Chip explains it, the material he used is tough stuff:
“The polycarbonate (a type of Lexan) is the same one used to make eyeglass lenses, the Lunar Module windows, F-14, F-15, F-18 canopies and bulletproof cashier windows. It’s UV resistant and retains its structural integrity to 400 degrees F. The silicone is 3M Hi-Temp Red; once cured, it doesn’t pass moisture or deteriorate from heat up to 450 F. The screws to hold the parts together are tempered nylon. No rust, and while they do absorb about 2% moisture by volume (if it gets past the silicone seal) it only serves to make them a bit tighter in the hole.”
Pictured below are the two blocks I tested out.
Below is a close-up of the heatsink used for the plastic block. It does not have a lot of surface area compared to more aggressive air-cooled heatsinks (e.g., Alpha, Global Win) so how it performs will be interesting.
Per usual, I used the stacked portable peltier rig; this puts out about 100 watts, cooled by a 5 x 5 inch radiator and submersible pump. I mounted each block and ran it until temps stabilized.
Plastic: -33.8 C
Copper: -33.4 C
Surprised? I’m not – just as in air-cooling, surface area is a major determinant for water cooling efficiency. I tried this out (HERE) but my crude attempt was nowhere as good as what Chip accomplished. What’s interesting about Chip’s plastic block is the potential for larger encased heatsinks for higher cooling efficiency – needed especially for those of you running double or triple peltiers.
I think it also opens a new approach to water blocks that marries good heatsinks to a substantially higher performance level; is an Alpha water block around the corner?