Heat sink material

[jprince]

Hi all

Just starting the planning stages of my LED build for my 210 FOWLR. I am looking at using extruded aluminum u channel in 6 foot lengths like this.
https://www.brunnerent.com/Tools/Portfolio/frontend/item.asp?type=7&size=0&lngDisplay=0&jPageNumber=18&strMetaTag=

Anyone have any first hand experience or long term results from using something like it for an LED heatsink? Thoughts and comments appreciated.

Jeff

[Tron87]

Definitely don't tank my word as the last word, but my light fixture has run off L Channel from Lowe's for 1.5 years.

The corals are still growing, though I have no way to gauge light intensity.
I have 12x120mm fans blowing on my 12 LEDs. Got two fans becuase they came in a pack.

[jimnrose]

I used 5 U channels [1 1/4" x 1 1/4" x 1/8" x 5'] for my 72" x24" x 17" 125 gal tank. I got mine from a local awning mfgr for about $50. There is plenty of heat removal capacity for my 72 LED's. I did add 6 3" muffin fans (3 on each side) running at half speed to provide some convection flow.

IMO, you'll do fine. Jim

[King Nikon]

Lots of people use those for LEDs. It will work just fine it's just very important to make sure they are cooled VERY well. Since there isn't much material to them and there are no fins to help the cooling, they will get hotter much easier and possible burn your LEDs.

[jimnrose]

The U channel does have fins (the two vertical wings). I screwed the LED's to the heat sink with thermal grease to ensure good heat transfer. My fans are running low (low noise) and the heat sink temperature is 20 degree (F) above ambient with the LED's running at 2.2 watts each (average).
IMO, there is no risk. Jim

[jprince]

The U channel does have fins (the two vertical wings). I screwed the LED's to the heat sink with thermal grease to ensure good heat transfer. My fans are running low (low noise) and the heat sink temperature is 20 degree (F) above ambient with the LED's running at 2.2 watts each (average).
IMO, there is no risk. Jim

I like the sounds of that. You probably have what I am envisioning. I figure with a couple of fans moving air, it would be plenty to keep the heat dissipated. Not only that, I only plan on having 48 3 watt Cree's over the tank. Thanks for all the great input!

[jdykert]

Thanks for the good reference site for the aluminum heat sink. I just started looking at building my own yesterday, and I think I am hooked.

[marineaquariums]

heatsinkusa.com

[sfsuphysics]

I use U-channel as well, in fact I bolt a few pieces together to make a wider bit as needed.

That said, fans are only necessary if you really cram your LEDs tight together.

[jimnrose]

The U channel would dissipate more heat if they were spaced by at least an inch. I spaced mine by using aluminum strapping (1" wide) from HD.

Go Sox, Jim

[jprince]

I use U-channel as well, in fact I bolt a few pieces together to make a wider bit as needed.


I was thinking along the same lines. If I use u channel, then I can always leave room to add or shift the rows around with relative ease should I not like the layout or need to add more in the future. I would like to make the rows adjustable on the end tracks or maybe add j plugs or something for a quick connect should I need to add or move some. I actually have an awning and canopy company not far down the road.... maybe I can score some cutoffs for cheap!!:thumbsup:

[lucky_snapper]

I love RC so much useful information.. I have been debating weather to do a U-channel or a true heatsink with the fins..

[jprince]

Go Sox,

Red Sox Nation!! Gotta love it.

[sfsuphysics]

The U channel would dissipate more heat if they were spaced by at least an inch. I spaced mine by using aluminum strapping (1" wide) from HD.

Well my mind set is that by bolting u channel together they can transfer heat to one another as necessary, so if you have a system where there's no LED on a particular channel, or some LEDs are off, that they can effectively make a larger heat sink.

[kcress]

You should leave gaps between the U-channels for a flow. At least a 1/4 inch. Better would be 1/2".

[jimnrose]

Heat is transfered to the air by a combination of surface area and air movement. All heat sinks (for aquariums) are mounted horizontally but as the air temperature is elevated it wants to rise vertically. IMO, it's important to keep this in mind whenlaying out the LED's and the arrangement of the heat sink. Jim

P.S.Down here (in Florida) a Red Sox Nation club was started & met the quota of 600 members at the frist meeting. There are 300 on stand-by.