Jump to content
paul b

Water cooled LED fixture

74 posts / 5497 viewsLast Reply

Recommended Posts

Paul,

 

Seth Solomon was telling me the other day about a really neat chaetomorpha reactor that used LEDs and high CO2 water from a calcium reactor to grow the macro algae with mineral oil as the LED coolant.  After your water is warmed up by the LED heat, are you going to send it somewhere to cool it?  And if you run it through a heat exchanger in a closed loop, do you think mineral oil would be as effective a coolant as water?  

 

The reason I ask is that I'm thinking of installing LEDs in a vertical glass tube which runs down through an algae cylinder like the one Seth was describing.  I was thinking of installing a squirrel cage fan at the bottom of the tube to help the draw of the "chimney effect".   But I can see high humidity air interfering with the electrical connections.  

 

So I admire your idea of using thermal adhesive to mount the LEDs directly to the cooling copper tubing, and running warm water through the tubing to prevent condensation. This would probably work better than my idea of fan cooling with high humidity air.  If I make an algae reactor I'll need a lot more LEDs, do you think your system would support closer LED spacing without heat buildup?  

Share this post


Link to post
Share on other sites

Justin and I thought of this idea some years ago but decided it wasn't worth it to produce. There have been several water cooled halides that hit the market some time ago and led me to believe that a water cooled LED on copper tubing would work as well but could'nt figure out where the source water was from and how to use it in a marine environment. To build the necessary heat exchanger would add to the complexity significantly.

Coolling fans work great on a heat sink for only a small amount of electricity.....

Share this post


Link to post
Share on other sites

Are you guys talking about the Pax Bellum ARID chaeto grower?  I think they're really pretty, even if they didn't work, but they look like they work.  No idea what that thing is on the top, but it looks like a big heatsink or something.

 

http://reefbuilders.com/2015/09/24/arid-chaetomorpha-macroalgae-scrubbers-paxbellum/

 

http://reefbuilders.com/2015/11/12/pax-bellum-arid-filter-review-intense-grow-chaetomorpha/

 

They're middling expensive.

Share this post


Link to post
Share on other sites

AlanM, yes that looks like the system that Seth described.  And Rob, I'm glad you and Justin were smart enough to think several years ahead of the curve.  Someone was a genius to use the output of a calcium reactor to supply CO2 to an algae reactor.  I'm just trying to think of a way to use Paul's genius use of copper tubing as a heat sink for LEDs in an algae scrubber application rather than a coral lighting application.  

 

I think Paul's copper tubes dovetail with LEDs.  Both need the same environment: low humidity, no condensation, saltwater protection.  I agree with Rob about cooling fans but I worry about humidity.  My greenhouse environment is worst than most people's homes but in either case humid air would shorten the life of LEDs.   I don't mean to hijack Paul's thread and turn it into an algae scrubber thread, so I hope he doesn't mind a different angle.  It's just like his coral lighting application but with twice the lights and submerged.  

 

So how do you build it cheap?  I'm thinking of a glass flower vase inside a white (for reflection) 5 gallon bucket.  Maybe pipe cool air to the bottom of the vase so it warms and rises out the top but at least connect a series of Paul's copper U tubes from one vase/bucket to the next in modules.  I thinking this can be done in the $30-$40 range for anyone handy.  Now to get radical, why not put a long glass tube deep into the aquarium to light corals?  It would need to be removeable to clean algae off the tube.  

 

Does anyone see a WAMAS build party here?  We'd have to fly Paul down from New York for a day.  That's $100 for a plane ticket and $50 for beer.

Share this post


Link to post
Share on other sites

Dave, my system will be connected to a car heater core for the heat exchanger.  I think this system will run very cool and may not even need the water running because the LEDs are spaced about 2" apart and copper is almost twice as efficient at cooling as the original aluminum plate they were connected to.  And on that aluminum heat sink, they were mounted right next to each other with just some fans for cooling.  That aluminum got very hot but I think this copper tubing will just get a little warm and with the water running I think it will stay room temperature.  I am sure I can double or triple the amount of LEDs I am installing and in the future I may do that.  But this fixture will double the amount of light I will have over my reef so I feel that will be plenty.  This is an experiment and I designed it so I can easily change or add more lights.  I can easily add another copper tube across the middle.

And mineral oil can be used but it flows slower than water and if there is any sort of leak (which I doubt) it would be very hard to clean the copper sufficiently to re solder it as oil is not a good thing to solder on.  Also, if there is a leak, I will have a pint of fresh water on the floor instead of oil.  For this other reactor you guys are designing, I would need a diagram as my mind works in pictures. 

Share this post


Link to post
Share on other sites
I just soldered the wore management system on the water cooled fixture.  It's those small copper rings that will support the wires around the frame.  I installed about 20 of them.  Next I want to clean it up, make it nice and shiny, then shoot it with some clear coat to keep it from tarnishing.  The next step after that is to glue on the 72 LEDs and solder them together.  I doubt I will finish this for a while because of some hand surgery this week, but I will try,

 

2015-02-13%2005.00.03_zpsdasajnjg.jpg

Share this post


Link to post
Share on other sites

I finished soldering the 72 LEDs on the copper and tried the thing out.  I can't believe it works.  I had my doubts because the terminals on the LEDs are meant for a robot to install them on a circuit board so the terminals are the size of a pin head or smaller. 
Now to make the enclosure for the drivers and get a heater core.

Share this post


Link to post
Share on other sites

I decided to build my heat exchanger so I just ordered a bunch of 5/16" rigid copper tubing.  I realize I could use a heater core but after seeing these things work, I don't think I will need that much cooling.  I would also rather build the thing myself.

Share this post


Link to post
Share on other sites

Looking good!

 

One question, though - given the higher heat conductivity of copper, and assuming there's decent air flow around it, do you even need the water flow and heat exchanger? I understand in some ways that's the whole point of the exercise, but just curious. :why:

Share this post


Link to post
Share on other sites

LCDRDATA, I did run the thing for about a minute just as you see it on the bench and it did start to get warm.  I do believe it could be run just as it is which is why I'm opting for a smaller heat exchanger which I will build.  If I can keep the system running at about room temperature, I think the LEDs should last forever.  And you are correct, the whole point of this is to build a water cooled fixture.   If this works as good as I believe it will, I may build another one with twice as many LEDs, just to test the concept.   If I do, It will be nicer looking.

Share this post


Link to post
Share on other sites

I just got home from the hospital for some knee and hand surgery and was surprised to see my circulating pump for my water cooled fixture arrived.  It is smaller than I thought.  I figured I would post it before the anesthesia wears off and I start screaming.  This little pump is very cool but I hope it will run continousely.
I am tryng to type with two fingers from my left hand and not having much luck

2015-02-17%2005.26.59_zps8qwe9frc.jpg

Share this post


Link to post
Share on other sites

Paul, that's a beautiful light fixture.  Its easy to see why you want to clear coat it, it will look more like art.  We hope you recover quickly from surgery.

Share this post


Link to post
Share on other sites

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. 
2015-02-19%2000.00.02_zps4zuds7nj.jpg

Share this post


Link to post
Share on other sites

I've skimmed through some of the thread, are you just building this because you're bored and retired? Because a water cooled LED fixture might by the most pointless thing in reefing equipment. 

Share this post


Link to post
Share on other sites

I am never bored, but I am retired.  I think a water cooled fixture is extreamly cool.  I could have also made it oil cooled or Grand Marnier cooled.  But I opted for water as air cooling is so yesterday.

The control box is built and tested.  The copper tubes also arrived today so I can start building the heat exchanger.
2015-02-21%2002.07.57_zps4i07aimt.jpg

Share this post


Link to post
Share on other sites

I've skimmed through some of the thread, are you just building this because you're bored and retired? Because a water cooled LED fixture might by the most pointless thing in reefing equipment. 

 

I disagree. An AMMONIA cooled fixture would be significantly more pointless.  :tongue:

Share this post


Link to post
Share on other sites

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.

2015-02-22%2000.27.23_zpst33fcu0x.jpg

 

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.

2015-02-21%2022.48.20_zpscc24qoq3.jpg

Share this post


Link to post
Share on other sites

I re-designed and re built the water pressure switch and although it works better, I am still not happy with it so I can't install this fixture over my tank yet. That and I need to get a bunch of stitches out of my hand. The pump I have works good enough to circulate the water through the fixture, but it is hardly powerful enough to push the plunger all the way up in the switch so that it maintains a magnetic connection with the magnet switch to keep the LEDs energized. I need a stronger pump or a lighter plunger in the switch. There is a magnet in the plunger which weighs quite a lot and pushes back on the tiny pump a little too much. Tomorrow I will go to a LFS to get some of that cheap, thin walled plastic tubing they sell and build a much lighter plunger. If that works better, I will get the acrylic shield and find some help to aid me in getting this thing over the tank without dropping it in the water.

Flow%20switch_zpso3c98gwq.jpg

Share this post


Link to post
Share on other sites

I don't care if it's useless. It is totally cool. 

 

+1. In my opinion its never useless to make your own stuff and experiment. Thats how you get ideas for other things and evolve the hobby.

Share this post


Link to post
Share on other sites

I've skimmed through some of the thread, are you just building this because you're bored and retired? Because a water cooled LED fixture might by the most pointless thing in reefing equipment.

I think there are plenty of pointless things in the reefing world. Flake food, quarantining, UV sterilizers, bloodworms, brine shrimp, and bio pellets just to name a few. But of course those are my opinions and I am not the God of fish keeping. Although it does seem that I am the God of Reverse undergravel filters and now, water cooled LED fixtures. There is a plethora of fantastic, wonderful and unbelievable tanks on these forums, many of them much nicer than mine. But reefing is only one of my many hobbies, another one is making stuff out of copper and electronics so as you can see, this pointless water cooled fixture helps make my life complete, pointless or not. You would be totally "under amazed" if you saw some of the things I have built,over the years, many of which are even more pointless, but very cool. Some of those things were useful and at least one of which saved my life. Many of them made me a nice sum of money and some still do. So something that is pointless to some is gold to others. But I do appreciate your opinion as I appreciate the opinions of most people.

See this "rock". I built this for practically free. It is hollow and my tank is filled with this stuff. Do I need to build rocks after I already filled my tank with real rock that I collected in the sea? Of course not. But anyone can collect or buy rock. That takes no brains or creativity. And real rock is not hollow like this. One of my hobbies is cement work, which this "rock" is.

IMG_1009.jpg

 

See this M-16 I am holding in the jungle of Viet Nam? That is the only 30 round magazine you will ever see on that weapon. Did I really need such a thing? Actually, yes I did, and if it were not for that silly thing made from hacksaw blades, bamboo and some sheetmetal from a crashed helicopter, I may not be here today writing about pointless devices.

VietNam.jpg

 

Now this thing, I agree with you is pointless. It was a revolving algae growing system. I built it for fun and as an experiment. But it never worked well at all.

 

IMG_2238_zpsnzqspo9f.jpg

Share this post


Link to post
Share on other sites

 

Completed heat exchanger. I am so glad I decided to build it rather than buy a car heater core. It was a fun build and a core would have been very heavy and over-kill as I don't need that much cooling. I am getting the stitches out of my hand tomorrow and if I get the time I need to drive to the Bronx to buy the acrylic to make the splash guard. Then it is ready to install. I am rather proud of this thing and am glad I built it.

 

2015-02-242004.16.51_zpsugse9dzk.jpg

Share this post


Link to post
Share on other sites

Paul, I'll contact you for the copper work when I'm ready to get my distillery up and running.  If you can build that one-handed you can probably make some nice still parts. 8)

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...