How many led's without fan

[kevantheman35]

How many royal blue cree XT-E's can I put on a 1''x15'' heat sink without needing a fan. I have 9 available. Looks are everything since this is a rimless tank and I really don't want an ugly fan hanging there. Anybody have a pic of there set up?

[ghellin]

What kind of heatsink? What drive current? Is it going to be open at the top or a floating canopy? These will help us help you figure this out. Here is my heatsink they are 1" wide and 10" long I have 4 LEDs over about 8" of heatsink and they are driven to 750 ma and there are no fans with no heat.

Hope this helps.


http://i737.photobucket.com/albums/xx12/ghellin/IMAG0915.jpg
http://i737.photobucket.com/albums/xx12/ghellin/IMAG0913.jpg
http://i737.photobucket.com/albums/xx12/ghellin/IMAG0336.jpg

[kevantheman35]

http://www.rapidled.com/09-led-actinic-supplement-kit/
This is the exact kit I am using. I am cutting the heat sink down to 15'' to match the length of my metal halide reflector. I am mounting this directly to the front of my reflector some how. It will be clearly seen which is why I would like to go without any fans. Thanks for taking the time to help

[kevantheman35]

If you know of a better alternative for a heat sink used for this application please let me know. I couldnt find a black one anywhere near the size I need unfortuneately :(. I have seen L brackets used for I would assume they would get even hotter since they have less surface area?

[ghellin]

That heatsink is fine with that driver you should be able to do 7 or 8, maybe the 9th.