led heatsink?

[uireef]

Hi I'm doing a 48" heatsink led fixture with 24 cree 3w leds. Ok my plan is to mount the leds on a aluminum plate the length of the heat sink. Doing this so I can mount the leds on the bottom and have the wire on the other side. I plan on spacing the plate about an inch or less from the heatsink. Will the heatsink still work as if the leds were mounted to it? Also I'm running a ati powermodule down the middle. How many dimcables do I need to run the leds and powermodule with the apex?

[SnowManSnow]

I'm NO EXPERT as some here are, but IMO you'll loose a GREAT DEAL of effectiveness of the sink by doing that.

If you want to just hide the wires. You can drill holes in the sink and run the wires up and through the fins.

B

[uireef]

Ok thanks. Save me some doe. As much as as spending on this I want to make it look worth it.

[der_wille_zur_macht]

You might as well toss the heatsink if you're going to do that, and just use lots of air movement (fans) against the aluminum plate.

I concur with SnowManSnow regarding hiding the wires - just put holes next to each LED and feed through that. Of course, you want to make sure the wires aren't in danger of rubbing/catching on burrs on those holes and cutting the insulation.

[uireef]

So ill mount everything on the heatsink and get some mesh sheet of metal and put holes in it for the leds.

[Dustin1300]

Why not watercool the heatsink like my computer? Great heat reduction and little/no fans needed thus reducing the noise and increasing the life of the LED by keeping temps down? This is a crazy idea (DIY forum, right?!?) but you can pick up these kits relatively cheap.

[der_wille_zur_macht]

So ill mount everything on the heatsink and get some mesh sheet of metal and put holes in it for the leds.

Not sure if I understand what you're talking about - I don't see how you'd need the heat sink AND a piece of sheet metal.


Why not watercool the heatsink like my computer? Great heat reduction and little/no fans needed thus reducing the noise and increasing the life of the LED by keeping temps down? This is a crazy idea (DIY forum, right?!?) but you can pick up these kits relatively cheap.

Complicated, expensive, and failure-prone IMHO. Water cooling in a PC case makes sense because you have a ton of heat generators (ICs) packed in a nearly airtight box with a form factor dictated by it's function. In most aquarium builds, we don't have the same restrictions.

Plus, show me a water block (to mount the LEDs on) big enough to provide coverage over a typical aquarium! You could use square Al tube, but the tube on it's own is probably enough assuming you get a little air moving over it. In that case, the water cooling rig is just adding complexity (a pump, plumbing, etc.).

[Dustin1300]

That was just a crazy idea I threw out. It would require customizations in regards to a heatsink but failure prone I would disagree with. They are very reliable but would be very complex to integrate. :spin1:

[uireef]

Just going to with acrylic painted silver on one side to match the heatsink.
How big of a whole do I need for the cree led lense?

[uireef]

Just going to with acrylic painted silver on one side to match the heatsink.
How big of a whole do I need for the cree led lense?

[der_wille_zur_macht]

If you are thinking of putting a piece of acrylic "tight" against the LEDs/heatsink with small holes for the LED to poke through, I would advise against it. By the time you got a hole big enough to not obstruct the LED or cause thermal issues, it's going to defeat the purpose.

Instead, use a (clear) splash shield made from acrylic and mount it an inch or two off the face of the heatsink.

[uireef]

yes put a acrylic shield about an inche. Off the heatsink but also have holes for the leds to polk through. Also paint the side facing up silver to hide the wires.

[der_wille_zur_macht]

Don't paint it and don't drill holes. An inch away, the light spread from the LEDs is going to be very large - to get the light through, you'd need very big holes, which would totally defeat the purpose.

Drill holes through the heatsink next to each LED and run your wiring on the back of the heatsink (between the fins) if you're really concerned about hiding it.

[uireef]

thanks for your help. Why not paint it and drill holes in acrylic? Tink the heat? Do you have a pic or link of a light.