Will the work as an LED heatsink

[undertai]

I was at home depot the other day getting some wood to build my DIY LED build. When I was walking around looking for someone to cut the wood pieces . I came across this.

Its call an Aluminum Hawk

http://www.antonline.com/p_AH659-GP_485239.htm?sID=GP

Its size is 13" x 13" square and will go perfect for my 24G Aquapod. Right now I'm doing 24 LED's for the project but with this size I can probably add about 6 or 8 more leds to the project at 2 inch spacing. The leds are cree xr-e q5's and the cree royal blue. The middle or the hawk has a hole were you are suppose to screw in the handle. But I can just have all my wires run through the hole since I want be needing the handle anyway. What do you guys think of this as the heatsink for the leds. Also I will be running 2 meanwell on dimmables drivers 3 drivers if I get the other leds.

[mcgyvr]

will it work...sure... and you will get a free handle.

but a heat sink is all about surface area.. without fins you have very little surface area.
but I've seen many just using a sheet of aluminum like that with no problems.. I've got a true heat sink on my LED build with 24 LED's and it doesn't even get warm to the touch. stays cool as ice. the cooler you keep the LED's the longer they will last

[Neogenocide]

I say it will work, however you will not be able to run it in a passive application. You will also need much higher airflow across it just to keep it cool. Anything can be made to work, it just if your willing to accept the other issues it may bring along with it, like a nosier fan that moves a higher volume of air.

Scott

[Tony78]

Have you seen this site? This guy does individual heat sinks... you can buy just one from him.

http://www.heatsinkusa.com/

[der_wille_zur_macht]

Philips Lumileds published a good thermal design guide a few years ago. It's currently marked as obsolete but still contains a lot of great information:

http://www.philipslumileds.com/uploads/232/AB05-pdf

Being in danger of providing misleading information (I haven't done the math), your build sounds too power-dense for a horizontally mounted flat plate heatsink.

[XSiVE]

I think you're going to be looking at some pretty hot LEDs if you go with that and 24 LEDs, but it depends on how much current you're throwing at them too..

[undertai]

To help will cooling I'm already doing fans into my custom canopy. Also I can pickup some cpu mounts to add to the top of the metal sheet. And just use some thermal paste to attach the fins to the metal sheet.

Checked heatsink USA already. Shipping cost me more than the heatsink that I would need. Heatsink is like $15 shipping is $15 plus a $5 fee; so a total of $35. Where the hawk is $12 and the fins are free as I still have some extras laying around the house.

[theatrus]

Its a little hard to calculate the thermal resistance of a trowel without more information :-) My only concern is the probably thinness of the plate.

If you are employing some form of active cooling, and carefully monitor the temperature during operation, it should work. What current were you planning on driving your LEDs? You can relatively easily calculate the thermal output.

[undertai]

24 leds running at around 670ma to 700ma for 8 hours. (Depends on brightness and corals)
3 royal blue (moonlights) running at 700ma 24 hrs a day.

Their will be two fans built into canopy. 2 fans blowing air in; 1 on back of canopy other on left side of canopy. With 1 open air hole on right side of tank for air exit.

I think the metal peice is like heavy guage hard-rolled aluminum. Its not flexiable or bent easy so no problem of the sheet sagging under led weight.

[theatrus]

Heatsinks are generally rated for thermal resistance to ambient, both under laminar convection and forced air. To simplify a bit - more surface area = low thermal resistance. However, to determine the actual performance is an amazingly complex process.

If you carefully experiment, you can determine the performance of your plate under some conditions. Start at very low currents and carefully monitor ambient and plate temperature. Make sure the system is stable before bumping up the power. You will likely need a fan moving air over the plate.