LED Heat Sink Principles

[Imbarrie]

I was following a post that included a build that incorporates LEDs on a flat sheet of aluminum.
From an early interest in thermodynamics I can recall the relationship to surface area, composition and fluid contact time.
This link pretty much sums up the importance of all three and explains why we should not use a flat sheet for a heat sink.

http://en.wikipedia.org/wiki/Heat_sink

 

[Anthony.Luciano710]

what about with liquid cooling

 

[Imbarrie]

Why liquid cool something that has plenty of efficiency without it?

The people using liquid cooling are doing so to overdrive certain things for short term gains. Like CPUs, you can, but why?
They are doing that to achieve a benchmark level.

A reef tank requires long term stability. The engineering used in this hobby has to be bullet proof and reliable. It needs to work 100% of the time for as long as it can. Every mechanical system will fail, what we do in this hobby is use the systems that have long life spans.

 

[Anthony.Luciano710]

no liquid cooling if its on an aluminum plate

Why liquid cool something that has plenty of efficiency without it?

The people using liquid cooling are doing so to overdrive certain things for short term gains. Like CPUs, you can, but why?
They are doing that to achieve a benchmark level.

A reef tank requires long term stability. The engineering used in this hobby has to be bullet proof and reliable. It needs to work 100% of the time for as long as it can. Every mechanical system will fail, what we do in this hobby is use the systems that have long life spans.

 

[Imbarrie]

Why not use a traditional heat sink?

Im still trying to find active cooling of flat aluminum. Even CPU liquid cooling has increased surface area.
I get where you are going, but for a DIY project, experimentation is best left at the OEM.

 

[Anthony.Luciano710]

because i already built the leds. someone was telling me i can get a resevior under the tank and then silicone any openings for the wires come through the aluminum and then put a pump in the resevior and pump water across the whole aluminum sheet and then go back into a pipe and back to the resivior on the other side. also can i just use small traditional heat sinks and glue them with thermal glue to the aluminum sheet to help a little because al the leds are glued down thats why i can put them on a heat sink right now.

Why not use a traditional heat sink?

Im still trying to find active cooling of flat aluminum. Even CPU liquid cooling has increased surface area.
I get where you are going, but for a DIY project, experimentation is best left at the OEM.

 

[JonnyJ]

experimentation is best left at the OEM.

couldn't have said it better myself.

 

[noobzy]

because i already built the leds. someone was telling me i can get a resevior under the tank and then silicone any openings...

Anthony, it sounds like water cooling would be the most complex solution to your particular problem. Personally, I'd go with thermal glued heatsinks on your plate, and ensure that you have fans circulating the air.

 

[Anthony.Luciano710]

i have 6 small computer fans but ill definitly get some high powered ones 2 because this is a lot of money to destroy here and a lot o people told aluminum sheet was fine but i guess not.

Anthony, it sounds like water cooling would be the most complex solution to your particular problem. Personally, I'd go with thermal glued heatsinks on your plate, and ensure that you have fans circulating the air.

 

[JonnyJ]

This is one of those things that just makes me say why?

Heat sinks shouldn't be avoided.... im not sure why anyone would try to use fans or any other type of cooling to make up for something as simple as a heatsink.

Some of the cheaper companies, mainly the asian ones use very thin heat sinks and more fans to cut on costs.



You say you spent a lot on your leds...protect your investment with a heatsink.

 

[Imbarrie]

Personally, I'd go with thermal glued heatsinks on your plate, and ensure that you have fans circulating the air.

This is a great idea if you cannot get those LEDs off the sheet.

 

[Anthony.Luciano710]

ok i will but i can not remove 144 leds and everything i built for it to put them all on heat sinks now. s it ok if i buy the heat sinks not and thermal glue them to the aluminum sheet. wont that be even better because i have the surface area from the heat sinks and the aluminum sheet.

This is one of those things that just makes me say why?

Heat sinks shouldn't be avoided.... im not sure why anyone would try to use fans or any other type of cooling to make up for something as simple as a heatsink.

Some of the cheaper companies, mainly the asian ones use very thin heat sinks and more fans to cut on costs.



You say you spent a lot on your leds...protect your investment with a heatsink.

 

[Anthony.Luciano710]

ok you guys convinced me to buy heatsinks. but like i said before i can not take the leds off the plate they are on now. so i will just glue these 3 heatsinks with thermal glue or screw it on. what do you recommend? i got 3 900 square inch heatsinks.

 

[Imbarrie]

The best quality thermal paste you can find. That creates the best lamination and will provide the most efficient heat transfer. You can use screws to secure it. But the thermal paste is a must.

 

[Anthony.Luciano710]

ok i have a few tubes of the arctic alumina thermal adhesive. is that high quality?

The best quality thermal paste you can find. That creates the best lamination and will provide the most efficient heat transfer. You can use screws to secure it. But the thermal paste is a must.

 

[Imbarrie]

Check with a PC store. They use it on motherboards.

 

[CHEMCHEF]

Thats not a heat sink.
THIS IS A HEAT SINK LOL

 

[Anthony.Luciano710]

LOL it looks like a heat sink/chiller

Thats not a heat sink.
THIS IS A HEAT SINK LOL

 

[tosiek]

Your going to need at least a half pint of thermal paste to cover that area. =0) So get alot of it. You can buy it bulk online if you look around and it shouldn't cost too much. Here is the coolermaster one at Newegg. And yes, gluing a heatsink using thermal paste and screwing it together is the easiest and best way to fix the problem. Not setting up a cooling system thats going to run you the same amount of money if not more and you have the chance that if it leaks its probably going to leak right into your tank.

I don't know how cheap you got the aluminum plate but a heatsink would cost you what? 20-50$ more for a 12x48" piece? I think thats a good investment to make on the 700-1000$ your spending on LED's and drivers.

Thanks for starting this Barry.

 

[Anthony.Luciano710]

ok thanks for the link for the thermal paste im ordering it now. yesterday i ordered 3 10x7 heatsinks and i will just glue them to the top. i know its still now as much as its supposed to be but it will definitely help right? im going to put 6 small fans and im looking for 2 high powered ones to go across the bottom and top of the aluminum plate by the way i paid $98 for the aluminum 72x12 .190 thickness. also should the thermal paste be a thick layer or thin?

Your going to need at least a half pint of thermal paste to cover that area. =0) So get alot of it. You can buy it bulk online if you look around and it shouldn't cost too much. Here is the coolermaster one at Newegg. And yes, gluing a heatsink using thermal paste and screwing it together is the easiest and best way to fix the problem. Not setting up a cooling system thats going to run you the same amount of money if not more and you have the chance that if it leaks its probably going to leak right into your tank.

I don't know how cheap you got the aluminum plate but a heatsink would cost you what? 20-50$ more for a 12x48" piece? I think thats a good investment to make on the 700-1000$ your spending on LED's and drivers.

Thanks for starting this Barry.