LED-WATER-HEATSINK

[LedElk]

Hello! I am a noob DIY-LED-GUY, in need of assistance. Now, I'm about to fire up an LED-DIY grow and since this is my first time ever making an LED-LAMP I've decided to jump straight into the deep end of the pool and do a water-cooled rig. As pipes are mostly round there was an issue with lack of flat space to mount the LEDs on and the right parts was hard to find, so it kind of just ended up like it is.

My question is:

will it work?

I have an aquarium pump that goes between the "radiator" and the rig. The rig is supposed to cool 6x10w LedEngin LEDs. I have no idea how much heat they generate or how this heatsink will handle it. It might heat the water faster than it cools and end up like an expensive short-lived radiator.

So, I'm hoping someone with the XP can just take a look at this thing and give it a "YES" or a "NO". The four sides are about a foot each.

Attachment 290303Attachment 290304Attachment 290305

LedElk Reviewed by LedElk on 03-17-2013. LED-WATER-HEATSINK Hello! I am a noob DIY-LED-GUY, in need of assistance. Now, I'm about to fire up an LED-DIY grow and since this is my first time ever making an LED-LAMP I've decided to jump straight into the deep end of the pool and do a water-cooled rig. As pipes are mostly round there was an issue with lack of flat space to mount the LEDs on and the right parts was hard to find, so it kind of just ended up like it is. My question is: will it work? I have an aquarium pump that goes between the Rating: 5

[Mal420xl]

that looks like it could develop sweating problems. maybe try to duplicate a pc/drive cooling system.

[LedElk]

sweating problems

What exactly is sweating? Are you thinking of condensation? It had not occurred to me at all, I'll have to take a look at that!

Do you think this rig would manage the heat? It's basically a solid heatsink but with running water going through it, I'm not counting very much on the "radiator" to dissipate alot of heat.

[Mal420xl]

yeah i meant condensation. i think it will but you need fill in the middle section also. the idea is to use water to move the heat off. even if you just have a fan blowing over the coil it can help. just make sure you make absolutely sure its all water tght. and insulate the hoses. take thermal tubing and run it thru the fins of the heat sink.

[LedElk]

The middle-section is actually where I was going to place a cpu fan/heatsink with 3x10w Leds... I'm trying weezards advice of separating the reds and the blues so that I can adjust the height of the two lamps and thereby control the R/B-ratio.

So what you see there is basically the whole thing, except for the aquarium pump and the second lamp of course.

I'm placing the coil beneath the air-intake so I hope that will be a sufficient airflow. If not, I'll try to mount a small fan on it, like you said. As for water-proofing I guess it would be a small catastrophe if there was a leak! I'll make sure to have it running atleast a day before mounting the LEDs to find the weak spots.

Thanks for the replies, much appreciated!

I may have to rethink the independent-lamps plan to utilize the middle section for heatsinking.

[Mal420xl]

sounds good man be cool to see it when its done

[LedElk]

sure thing! I'll post an update when it's all assembled. Got my seeds in germ yesterday, so things are happening!

[Weezard]

Howzit Ledelk?

Way to go, brah!
That's a clever design!
It should work a treat too.
Wish I had thought of this.

Don't worry about condensation though, your water temperature will be higher than the ambient at all times.

As for leakage, I suggest that you disassemble and reassemble using teflon pipejoint tape.
It allows a tighter fit, seals micro-leaks and separates and insulates the dissimilar metals.

(If you use dissimilar metal with water, you create a voltaic junction.
In effect, a small battery that will actively corrode the joint.)

Then polish the cap heads until they shine like good deeds in an evil world.
The led/cap interface is the most critical for rapid heat transfer from the junction.
All the rest can handle some "lag".

Just for safety, I'd add a cheap 50 ℃ thermal switch to cut the power.
Water can not be compressed, so a radiator fan failure that allows the water to reach it's boiling point might create some drama, yah?

Now I'm gonna pull up a hammock and watch.
Attachment 290322

Aloha,
Weezard

[LedElk]

Hello, Weezard! Pleased to meet you, sir I've been reading alot about LEDs in these past few months and your contribution to the area has been very helpful! :thumbsup::thumbsup:

Now, as I said earlier, I would like to make two lamps for ratio-control, so I'm glad to hear you think it should work without adding more heatsink (I'm assuming that's what you meant). The rig was just put loosely together to get the pics so disassembly will not be needed. I wasn't really sure how I would get the joints watertight, but my default plan was to use some kind of glue or sealant. I haven't heard about the "voltaic joint" phenomenon, and although the glue might have prevented it, I will definitely be looking into using the kind of tape you described. It might be a good thing to have a non-permanent assembly for later, if I can avoid the glue alltogether!

As for safety, I'll try to find such a switch as you described there, but could I also add a fuse? If there is a leak somewhere and it shorts the circuit, could I save some expensive LEDs by adding a fuse to the beginning of the circuit and stopping the floodwave of current before it reaches the LEDs, or is that not how it works? (Guess the best thing would be to make the rig water-tight from the get-go, right?)

Well, thanks for tuning in!

[Weezard]

"(Guess the best thing would be to make the rig water-tight from the get-go, right?)"

Absatively!
Half the battle is knowing what not to worry about.

Problem with fuses, even the super-fast micro-fuses, is that LEDs blow faster!
They will handilyprotect your fuses from current spikes.

By all means use a fuse.
But don't expect any LED protect.
Bet da fuse, you gonna lose.
Betta buy a smoke detect.

By-m-bye
Weeze