Water cooled COBs

ohdang said:
i haven't done any of the math
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to sink 0,6KW of heat energy - you need to vaporize 1L
Your lamp 300W / 15H will produce ~ 3200-3600W of heat.
A part is lost at the front side and LES (20% till now)
Count with 80% max and you will need to substitute ~ 1.5 Gal
Mount a room fontain on top of your 5 Gal bucket or a little cooling tower.
@ watertemp > 32°C your lamp and your waterbucket start to transfer
much moore heat to your grow room
S6002014.JPG
You see 320W lamp with 15 Gal bucket .

@ equilibrium i had air temp 28°C watertemp.(water surface) 33°C adding ~ 1,5 Gal of water/day - no need to blow out much air.

With only 5 Gal bucket i would mount a plastic pipe over a bigger bottle - drill some holes over the waterline and put a dimmable fan on the top to produce RH or connect it directly with the outgoing air - with a good fan power maybe you can suck your 5 Gal away in 1 day and get your room to 20°C. Make shure not to run your pump empty.bongsmilie(:
 
ttystikk said:
Another option is to drop the return water back into your garbage can from a height of a foot or two. This will also encourage evaporative cooling..
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yeah i agree on that, i remember the first time i had the return line above the water line, so the flow would sorta splash in the container creating small air bubbles to move around the water at the surface level. That container was actually 15 gallon trash bin.

what worked better before that was a 10 gallon bin, the reason was surface area. not just water to air surface area, but the container had more contact with the ceramic tile floor, which actually help conduct the heat out of the water.
I always wanted to use a large steel trash can. you could do that with 5 gallon steel buck and just make sure you line it with a heavy duty plastic bag. then you can just blow a fan over it intermittently to save on power. the container would be like a radiator basically and a fan would act as active cooling.
 
ohdang said:
How have you all gone about attaching cobs to the cooling bar??
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https://www.rollitup.org/t/water-cooled-cobs.909674/page-13

If you don`t like * the COOLMAC-SYSTEM * and direct contact of platine and water - you
can do it like that:

Use thermal grease (often they have better heat conductivity and can get to thinner layers than glue) - clean the outline and " secure " your chip with 4 points of a hard adhesive for metalls.(super glue)
If you want to change your chip - just scratch these points with a needle.
 
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ohdang said:
@DIY-HP-LED , @mahiluana , @ttystikk How have you all gone about attaching cobs to the cooling bar?? I'm brainstorming a method that won't require glue... some kind of bracket perhaps? What are the methods available?
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Not really much available that wont take excessive time and/or money. 2 part epoxy is cheap and easy to apply. Mix together and apply all around the edges of the cob to the heatsink. You could lift the entire Assembly by the cob and it would hold up. Just make sure the cobs you have on there are the ones you want because it will take some work to get them back off.
 
Ken Beck said:
it will take some work to get them back off.
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The chip and your heatsink can get destroyed easily.

Use thermal grease (often they have better heat conductivity and can get to thinner layers than glue) - clean the outline and " secure " your chip with 4 points of a hard adhesive for metalls.(eg. super glue)
If you want to change your chip - just scratch these points with a needle.
 
Ken Beck said:
Not really much available that wont take excessive time and/or money. 2 part epoxy is cheap and easy to apply. Mix together and apply all around the edges of the cob to the heatsink. You could lift the entire Assembly by the cob and it would hold up. Just make sure the cobs you have on there are the ones you want because it will take some work to get them back off.
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I'm definitely interested in methods that might take a little extra time and effort.. Especially if it will keep the setup somewhat modular and not require cleaning of the cobs and cooling blocks. I've seen the website big blue saw, and the idea of custom fabricating something seems fun. It couldn't be that hard to configure some sort of bracket that would go over an ideal cob holder style chip holder. So it would be cooling block, TIM pad, cob, holder, extra bracket. If you were using rectangular tubing, it would really only need to be a couple pieces of metal with some screw holes which could clamp on both sides of the tubing.. Maybe put some soft rubber or foam to keep the cob holder in place against the bracket.
 
1212ham said:
I'll soon be testing this "thermal plaster"... http://www.ebay.com/itm/Heatsink-Th...277735?hash=item465fff4d67:g:VRIAAOxyaURThZk1
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I may not bother testing the adhesive, I tested some paste of the same brand (Stars) and the cob was about 10°C higher than with Arctic MX-4. I tested by running the cob on a CPU water block with stable water temperature and measured voltage, works very well. Lapping the anodized and machined surface of the water block had zero effect! I plan to test that again. I'll do more testing if my new pump ever arrives.
 
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