50 watt 120 volt full spectrum led. Needing heat sink.

markstrimaran

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Going with 4 chips at 200 watts, over a 18 x 48 surface. Thinking of a aluminum 1/2" bar as a heat sink.

This one lite is cooled with a large magnet and a soup can full of water.

Kind of like to use water to cool, or make the heat sink big enough to be self cooling. I am planning an mixing in some greens to whiten the lights.
 
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CarpCharacin

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Just make sure you use thermal adhesive between the chips and the heatsink, it makes the heatsink cool better by increasing the efficiency of the thermal transfer from the lights to the heatsink.
 

Tarsun

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Make sure its adhesive and not thermal paste. The paste works well but you would need to secure the light to the heatsink.
You can pick up computer "tower heat sinks" for cheap on line. It might be a little better than a can of water. lol

The aluminum bar could get heat soaked and not function was good as you'd expect if the chip sets get really hot, which i'm pretty sure they do. You can add a fan to a smaller heat sink or add cooling fins to make it more efficient.

Adding a small aluminum heat sink on top of the aluminum bar above each chipset would help out allot.
 

markstrimaran

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Currently useing a .002 " epdm rubber adhesive.

The can sink is my test light to see how hot these 50 watt chips get.

I will probably use 2×1 aluminum tube with the ends plugged, then drip water thru, with the overflow heating the tank.

20181224_163051.jpg
 

Tarsun

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You have to be very careful when you run water in such a close proximity to electronics, especially when every part of the build is conductive.
 

markstrimaran

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Thermal adhesive would probably work better than the EPDM adhesive.
I know EPDM is non galvanic with aluminum. Probably not the best but I have it on hand. It's also very heat tolerant. Were some of the others are brittle and will eventually crack and cause a air gap with a glued only connection
You have to be very careful when you run water in such a close proximity to electronics, especially when every part of the build is conductive.
It will be grounded to a GFI , and the connections sealed water proof with EPDM.
 

CarpCharacin

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Thermal adhesive is heat conductive, so it will work more efficiently, and I think most thermal adhesives are non-conductive also.
 

markstrimaran

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The led is still going, but it is growing some fluff algea at 50f. Which is too cold for my cichlids.

I will try a sealed 316stainless steel 1" x 2" tube, about 18" long. Filled with water. As the heat sink once I find some scrap.
Might make a tester with mild steel, with the same volume as the can but long and thin.
 

markstrimaran

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So far these lights grow only fluff algea. All the long strand has died .

Might make a good candidate for a algea scrubber. But then at 59'F . I don't really know.
 
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