I thought about this way also. separate fans will use a bit more power but the heat removal will be more efficient as in a long aray driven by a single fan the air temp would be more by the end.

which fans are you using?

Steve

Yes !

But notice I said THERMAL mass. Think of it like thermal capacitance or heat capacity. In the end though, you are correct -it's about the transfer from one medium to the other. You can actually have a very small and light heat sink but at some point, as the thermal mass decreases, you'll need a fan. Whereas with a more thermally (and to an extent, physically) massive heat sink, you may get away without the fan.

ok you are using different terms than we used in thermodynamics :mrgreen:

for instance heat capacity is how much a material will hold, which is what we don't want in this aplication as we want it to transfer it as fast as it can, not hold it.

and thermal mass is realy a measument to the resistance of temp change.. more specificaly the ability to hold heat and release it slowly, which again we don't want.

what we want is a material that has a high thermal conductivity, which means it passes on heat very easily when there is a temp difference.

so we mean the same thing I guess, but your choice of words confused the issue :wink:

Steve

I ordered the Pressurizing Cooling Fans from Steve's LEDs. I also ordered most of the LEDs for my build and drivers from him.

cool, I have been thinking of using his for a test build, but let me know what you think of his stuff. to bad you didn't have a PAR meter or live closer.. I would like to see how the edison LEDs preform compared to the Cree. I think my only problem with Steve's LEDs is he has no nutral white.

Steve

Will do, one of these days I'll update my build thread on some of my progress.

I just went with his 10K and blue leds, 56 of each. I then ordered some red and yellow LEDs from another supplier so I should be able to get the color and effect I'm looking for. I went with Steve's LEDs mostly because he seemed to have the best balance for performance and price plus his LEDs have a 90 degree spread so I won't need any optics which I prefer. The crees are nice but for the price I think these will be more than adequate for what I need.
I'll also be using the profilux PWM LED control 4 to control everything so I guess we'll see how that works out.

Princess Auto
 

Princess Auto had U shaped Aluminum Heatsink that you can use.

Hope this helps

I know this is a bit of a sidetrack from what you guys are talking about and it it works better living close to the border but this is what I did. I ordered heatsinks from rapidled, it was free shipping within the US. Many small towns along the border have businesses that will accept packages for Canadians. I got the package shipped to that business, gave the heatsinks plenty of time to ship and then went and picked them up. You have to enter into the states and declare them at the border but it easily saved me a couple hundered on shipping expenses. Just a thought for ya if your within proximity to the states.

I just wanted to add that the cheapest I found for heatsinks is LEDgroupbuy.com.

In Calgary, I got my C-channel aluminum at metal supermarkets. They have any kind of shape/metal you would need and much cheaper than Home Depot. http://www.metalsupermarkets.com/

you can get heat sinks from rapid LED they are canadian progressive reef now sell there product. You dont have to go through progressive to get them it is just an option