Water cooled LED fixture

[Rybren]

Man. What bad luck. I hope that Mrs. B is okay.

 

[Paul B]

The two of us look like we just filmed an episode of ER

 

[twilliard]

I will be with you Paul!
I am waiting for my back surgery and my wife was diagnosed with cancer
2 operations in one month in this house.. ugh with 5 kids!

Hope you guys heal up quick !
Prayers from my family

 

[Paul B]

OMG this is horrible. I wish you guys luck. W e just got home. MRI is good. S he has 5 staples in the back of her head, not to bad. Now she can get back to taking care of me.

 

[Rybren]

Good luck to your wife twillard. Cancer sucks!

 

[Paul B]

I am working on the pump/power supply/ shut off switch/ LED drivers etc and it is all in this enclosure, I tested the pump and am very surprised that that little pump pumps faster than my sink can supply. The pump pressurizes the system, pushing up the glass with the magnet in it, engaging the magnetic switch to turn on the relay that energizes the LEDs. It all works seamlessly and I may try to wire it all together permanently. My hand is all bandaged up so I will have a little trouble, but not insurmountable. I am now waiting for the copper tubes to build the radiator. If it all works together on a bench, I will go out and get the splash shield. I don't want to get that yet because I have to go to the Bronx for it and it will not be cheap so I will test the system first but I think it will all work perfectly.

 

[twilliard]

Love the yellow wirenuts reminds me why I have arthritis lol

 

[Jwalker814]

Just an option. Not sure how you ended up doing a heat exchange (saw you ordered ridgid pipes) but you can get an automotive oil cooler from ebay or local auto parts fairly cheap and plenty enough flow for what you are looking for. 7 row I would imagine to be ideal and excellent cooling properties!


Also too, I like the switch idea, not sure what LEDs you will be running but I would look into a way to keep the liquid flowing for 5/10 minutes after lights shut off as to help with actual cool down time.

 

[Paul B]

Jwalker. Originally I was going to use a heater core and I found some on line for about $30.00. That is about the same price as what I am spending on the thin copper tubing I am using to build the thing. I just like building things which is why I opted to build it. If my home made heat exchanger doesn't work good enough I will get a heater core. I don't think I will need to keep the pump running after the LEDs go off because I am sure the copper alone will have the capacity to absorb enough latent heat when the pump stops. The LEDs are about 2" apart so there is not that much heat to disapate anyway.
Twillard, wire nuts I have as I was also an electrician

 

[Jwalker814]

Wanna build one for a 84x24x24 200g tank?

 

[Paul B]

Not if I can help it. But if I do build another one, I will tweek a few things. I can't wait to finish this thing but I can't move to well yet. I still didn't get the stuff for the heat exchanger either.

 

[LILBUDDHA]

I see the thought behind it . It's no different than trying to keep high temp electronics cool . CPU's ,server's etc .
I wonder if it will make the colors of the leds shift . I know if you cool t5's at the incorrect temp u will get different results .
I would bounce it off Sanjay or Riddle on their thoughts .

 

[Paul B]

It will be tested very soon. I am almost done. It won't take more than a couple of hours to build the heat exchanger after I get the tubing.

 

[redfishbluefish]

........I wonder if it will make the colors of the leds shift . I know if you cool t5's at the incorrect temp u will get different results .
I would bounce it off Sanjay or Riddle on their thoughts .

A couple thoughts on this....first off this Rube Goldberg plumber's nightmare isn't going to be "cool," below say 65-70 degrees. So cold isn't an issue....even if this was a T5 fixture.

Secondly, T5's (fluorescent bulbs) work by ionizing vapor, and if too cold, it disrupts this vapor ionization thing causing color variations. The cold temperatures might also play with the phosphor coating, and the reactions going on there. I'm an idiot, so I don't know exactly. LED's don't do this vapor thing, so no impact on cold.

Now back to Paul's build......not sure if you thought of this, but my experience with race car engines, if the water flow is too great, it won't efficiently remove the heat. You might have to play with flow rates to get the most efficient heat extraction. Still following along......and the Rube Goldberg thing was in jest.

 

[Jwalker814]

Do you know the specifics of the individual LED? Number of LEDs?

Interested in building my own fixture with 14 or 28 channels on a 7' fixture so that I can emulate the change of light with sunrise/set

Help to have a friend who has a board etching setup so I can make a board for each channel to make wiring a breeze

 

[Paul B]

Redfishbluefish. I am quite sure this thing isn't going to cool to much, or too little. Almost any cooling will work in this configuration due to the spacing of the LEDs on the copper. I am sure I will have to tweek something when it is done, but that is the fun of it. I hope no one gets the silly idea that I really "need" a water cooled fixture. To me. This is fun, nothing more as I already have a light that works fine. The pump I am using is a DC pump and I can easily put a rheostat on it to control the flow, but I doubt that will be needed. I am drawing up the schematic now so I know where to place everything. I have 4 configurations I need to wire. The LEDs themselves, the pump/radiator with fans, the drivers and the flow switch.

 

[Paul B]

I finished the schematic and will start wiring it.

 

[Paul B]

The control box is built and tested. The copper tubes also arrived today so I can start building the heat exchanger.

 

[Paul B]

The system is finished except for the acrylic splash guard and some bleeder valves to get the air out of the system. It is being tested on my bench to see first of all how it runs and second, how efficient the cooling system is.


Here is the heat exchanger. I still need to put it in a housing and I may build another one to connect to it depending on how much cooling I need. It has been running for 15 minutes and the pipes and heat exchanger are only slightly warmer than room temperature.

 

[Rybren]

Looking great Paul. How is Mrs B?