Looking for heatsinks

[GMGQ]

The heatsink is to dissipate massive heat from the LEDs, which will theoretically extend their lifespan. Each of these little suckers generates a LOT of heat @_@

Just like any electronic component, the hotter it runs, the shorter its lifespan. A good example are CPU's and their honkin' heatsink/watercooling setups. Sure it will still run at the higher temperatures, but are you willing to risk burning it out? I think that's the fear.

Having said that, I do believe these big Amp style heatsinks are overkill for these LED setups. I just finished my 8LED build with a 6"x7" heatsinkusa heatsink, it's about 5lbs. It gets warm to the touch pretty quickly, but I have a 80mm fan sitting on top of it, running at about 5V (it's a 12V fan), and that's enough to cool the heatsink down to slightly cool to the touch.

When I do my next build, I'm using aluminum channels (not u-channel). I think the main thing is to slap on a decent fan to blow away the heat from the heatsinks, so they can continue to suck the heat away from the LEDs. I read that some guys would rather have a big ass heatsink, so that they can avoid adding a fan (due to noise) and just let it air cool. I cant even hear my fan when it's on.

Originally Posted by globaldesigns

Just wondering, I have look at a few of the DIY LED setups, and everyone has huge heatsinks.

I personally am not using LED, but if LED uses less energy and has less heat creation, why such a big heatsink? Just wondering, as my MH, just have fans with no heatsinks.

[SmallFry]

Originally Posted by calgaryreefer

Does anyone know of a place in Calgary or even online within Canada that sells heatsinks large enough to make LED lights, I know there is a couple in the US like heatsink USA, but shipping is pretty expensive, trying to look for local to save and to support our own industries at home!!!!

Thanks.

Wish I had better news, but when I was looking I drew a complete blank - I would've liked to get something locally, or even in Canada but found pretty much nothing. I'm instead going with a large aluminum channel with a smaller one nested inside (thermal grease between the two) and holes drilled in the bottom of the channels to allow air to rise up through instead of stagnating in the bottom of the channel. I will also be using some fans to push air up through and assist convection. I'll make it clear I don't know exactly how well this is going to work since the light is still in the build process - I will be watching temperatures closely during testing. I'm hoping this will work well since my LEDs are going to be fairly tightly spaced.

I'm also interested in the idea of using heat pipes to push the heat from individual LEDs to a number of processor coolers, each handling the heat form a number of emitters - mainly because I'm a bit of a nerd and think that heat pipes are cool.

Originally Posted by globaldesigns

Just wondering, I have look at a few of the DIY LED setups, and everyone has huge heatsinks.

I personally am not using LED, but if LED uses less energy and has less heat creation, why such a big heatsink? Just wondering, as my MH, just have fans with no heatsinks.

LEDs are very efficient at turning electricity into light with relatively little waste heat. That is not to say they don't produce waste heat though. The rub comes in the fact that the emitters are producing that heat in a very small space (i.e. the junction) so the energy density is high, and to make matters worse the junction needs to be kept relatively cool for reasons of efficiency and longevity. For this reason people tend to go for huge heatsinks that can soak up the heat at a prodigious rate in order to be sure those junctions are being kept cool. The bulk heat produced at the end of it will be a lot less than your MH lights which actually have to be very hot in the part of the bulb where the light is produced.

I personally suspect that these heatsinks are a little overkill, but they provide a handy broad flat surface on which to mount the emitters, and after spending hundreds on those emitters a large heatsink seems like a small price to pay for protecting the investment. Bear in mind also that most of these large, flat, finned heatsinks are by necessity mounted in the most inefficient way possible (i.e. flat, fins pointing up) with regard to convective cooling, hence the fans to offset this..


Besides, those big heatsinks just look so cool - especially if you can anodize it a funky colour!

[calgaryreefer]

i went to home depot today and saw some 1"x48" aluminum square tubes that might work, making them like a t5 bar, add enough fans it will work i think, i will try one to see how the heat is, but i suspect it will work really nicely.

[sphelps]

Originally Posted by calgaryreefer

i went to home depot today and saw some 1"x48" aluminum square tubes that might work, making them like a t5 bar, add enough fans it will work i think, i will try one to see how the heat is, but i suspect it will work really nicely.

I recall reading somewhere that 1.25" x 1.25" x 0.125" 6063 aluminum works best for this application.

[mike31154]

You could look around for a place that recycles electronic components, shouldn't be that difficult in a large city. They'll have plenty of heatsinks out of old computers etc. Trick will be convincing them to sell you the stuff rather than ship it off for 'recycling'. I recall when I lived in Ottawa, there was a place in the south end where you could get all kinds of surplus electronics dirt cheap.

Only downside I guess is that your lighting set up might end up looking like something out of a '60s horror movie.

[rstar]

I thnink it would be interesting to see a pc liquid cooling concept applied to cooling LED's. Most kits are inexpensive in the grande scheme of things and allow expantion.

[mason dixon]

Would empty aluminum soda cans work? Put the leds on an aluminum bar stock and then use some thermal glue to glue a bunch of soda cans end to end(caps removed) and have a pressurized fan blow air through the soda can tube?

[themastr]

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

Hope this helps

[Jfish]

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.

[justincgdick]

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/