Building a water cooled LED light

[Paul B]

I started this on my normal Tank reached 38 years old...in 2009! thread or whatever it is called but decided to put it here because it may get complicated. I am building a water cooled, copper LED fixture for my 6' reef to replace my existing DIY air cooled fixture. Do I need a water cooled fixture? Of course not. But it is a fun build. This frame will have fresh water flowing through it by a pump and will circulate to a DIY radiator under the tank (that may be a car heater core) That very short copper pipe is not a through connection and is just soldered on the outside of the pipe for support. There will be 72 LEDs on here that I am taking from an existing broken LED fixture that my good friend at Aquarium Village gave me. I fixed that fixture but couldn't use it in that configuration so I am using it for parts.

This is the fixture I am taking the parts from.



I punched out and soldered on the 72 copper disks that will support the LEDs. Now (if I get time) I will clean it up more and shoot the entire thing with some clear coat because copper turns green and ugly. This way my Steam Punk look will last. But before I do that, I will make and solder on the supports for the plexiglass shield and also the supports to hang it over the tank. I am waiting for the thermal adhesive. I still have to either build or buy the heater core for the cooling.

 

[ENB]

Awesome.

 

[johnsonpics]

Paul B, That is insanely impressive! I can't wait to see more!

 

[LongIslandAndy]

Paul, you are one wild and crazy guy

 

[Paul B]

Andy, now doesn't that fixture look a lot better now? This is the fixture of the future. At least in my house. Now I am going to make everything water cooled, my TV, radio, toaster, microwave and electric toothbrush. :biggrin::biggrin:

 

[mrdobie]

try a motorcycle radiator some have a built in 12 volt cooling fan.

 

[Paul B]

That would be very cool. But harder to get than a car heater core. Unless of course you have one. I am not far from Merrick

 

[mrdobie]

sorry don't have one but if you call a couple of junk yards (Freeport or garden city park (nhp) boarder) you mite be able to find one. good luck

 

[Paul B]

Thanks, I am sure I will find one. I am not looking yet, I want to see this thing light up first

 

[mrdobie]

we want pics and videos when done please.

 

[Paul B]

I searched for heater cores on line and can get one for less than $30.00. Not a problem.

 

[Paul B]

I decided not to use thermal switches for this project because I have a better idea. Today I built a water flow cut off switch that also allows me to see if the water is flowing visually. What I am planning to do is have the timer that turns on the lights, turn on the water pump instead of the lights. When the water starts flowing through the pipe, The water flow will raise a magnet encased in a glass cylinder that is in a vertical acrylic tube. When the magnet gets near the top of the cylinder, it trips the magnetic switch that turns on the LEDs. When the pump goes off, the magnet will drop, breaking the circuit to the lights. I would like to take credit for this, but I didn't invent it. I saw a very similar switch on the net. With this installed, the LEDs can't go on unless there is water flowing and if water is flowing, the fixture will stay cool. Even if the water leaks out of the system, the lights will not turn on whish is what I want. By looking at the position of the magnet, I can determine if water is flowing.

 

[lnevo]

Very cool idea, but not really the most efficient in terms of energy. Some small PC fans and heatsinks should cool these LEDs just fine. Also I think you said you were gonna keep the radiator below the tank. Maybe you could regain some efficiency finding a way to mount that on the wall or somewhere it wouldn't have to lift water to the very top of your lights.

 

[Paul B]

Inevo, thanks for responding. This will be a closed system so there would be no lifting of water, just circulating. There will be a very small water pump to do this. I realize fans could cool the thing as that is the way virtually all LED systems operate. This is just an experiment. Something to build and in no way a means to get more efficiency from the LEDs. I am having fun building it. When I am done, I will build something else.

 

[lnevo]

So your plans changed then as far as running the water to a radiator under the tank. It's definitely a cool thing to build. But what's the plan now for the radiator part?

 

[Odysi]

Hey Paul will this be enclosed in some sort of housing? Just thinking about condensation and that dripping copper into the tank. Hope it works out looks like a fun project!

 

[Paul B]

Inevo, same system and I am still using a radiator.

Odysi, no condensation as that only happens if you run cold water through the pipe.
There will be a plexiglass shield under the thing

 

[ReefWreak]

Really interesting idea. Reminds me of a lot of the DIY PC watercooling stuff that I've seen. Some parallels worth considering are containment of leaks on the copper tubing side, which it sounds like you addressed above (though if it leaks into the plexiglass housing of the LEDs, won't it ruin them too? Maybe add a drain for the fixture, or a leak sensor?).

One thing you haven't mentioned, which I'm not sure this is as much as an issue as with PC cooling, is galvanic corrosion between copper heatsinks and plumbing and either an aluminum or brass radiator. I know brass will have much less corrosion than aluminum, and in either case it may not impact the cooling loop dramatically, but just something to keep in mind when shopping cheap radiators.

 

[Paul B]

ReefWreck there will only be about a pint of cooling water in the entire system as there will be no reservoir. If there is a "leak" there will only be minor seepage and not a real leak because there will also be no pressure in the system. It is a simple recirculating system so even if there is some little seepage, it will evaporate long before it drips in the tank. Plus, there will be a plexiglass shield under it that will have the sides bent up and end plates on it that will contain any water. The entire system is copper so there also will be no galvanic corrosion. There is no aluminum or any other metals in the system. If any water leaks out, the pump will stop because of the water flow switch I devised and will test tonight.

 

[Paul B]

I tested the water flow, shut off switch and it works very nice. Now I need to solder on the copper management system and glue on the LEDs