Water cooling leds

Jonesfamily7715

Well-Known Member
I've played around with tec peltiers, they can get really cold especially if you stack em but not very efficient. The hot side gets really fucking hot Might be good for a diy dwc chiller or dehumidifier. I have everything to build a water cooled cob light, I will be using vero 29 SE , cmu 2287, and cxb3590 cobs with copper tubing coils for cooling, I also have a cpu radiator and a bunch of reds to add. Should be fun.
 

cdgmoney250

Well-Known Member
It’s a cool idea, but I would be worried about condensation accumulating on your cooling pipes/heat sinks in your grow room. I’m guessing you would exchange the heat outside of the grow area, but the heat sinking taking place inside the grow would likely get drippy with condensation, without adequate insulation. Unless you are just using ambient air exchange with a fan radiator combo, which then I would question just how effective the heat transfer would be for all the extra hassle without some serious airflow, which then you have the fan wattage creating heat also. You’ll have to adjust the grow room air temperature anyways, so passive cooling/air exchange just seems to make more sense for economical purposes.

My point being is 1 Watt = 3.412 BTU/HR
no matter how you slice it. I’m not sure adding more watts to cool only your lights makes any sense, if it isn’t for a serious performance advantage. It would seem to make more sense to water cool the grow area to the desired canopy temp, and just have a large enough passive heat sink to keep the chips from getting too warm. Or cool everything with water, I don’t know. Just my thoughts
 

cdgmoney250

Well-Known Member
I get condensation on uninsulated lines with 56F water flowing in a room with 75F ambient air temps, and that’s outside of my grow. If it was inside my warm humid grow room it would condensate like a fire sprinkler.

I’m not sayin that you would water cool your lights with that cool of a water temp, but if not, is there any point/environmental advantage/performance benefit? I mean you still gotta transfer the heat somewhere
 

1212ham

Well-Known Member
Ahhh yeah!

Just gotta be mindful when mixing both copper and aluminum parts in a cooling loop. Not too big of a deal as long as you use extra anti corrosion inhibitors in the coolant..
:razz:

What latest strips you think would work best with 4' lengths of 1/2 or 3/4" square tubing? Not sure where to even look on Arrow..
The quote is from another thread, but I think it fits here.

I suggest single row strips on 3/8" or 1/2" tube and possibly two row strips on 1/2". Something wider for multi row strips.

Several years ago I used Bridgelux EB Gen 2 on 1/2" square tube, very effective. They were recently removed and my GLA strips with 1/8" flat plate sinks were strapped on. You might be surprised how suddenly the air temp drops when the pump is turned on!

For strips, I'd love to find flat aluminum extrusion with a small water passage. Hmm, possibly small square tube attached to flat plate with Devcon F epoxy or thermal paste/adhesive... the wheels are turning... I have ideas!

I've been using distilled water, any ideas for a non toxic corrosion and bacteria inhibitor for aluminum?
 

Drop That Sound

Well-Known Member
I get condensation on uninsulated lines with 56F water flowing in a room with 75F ambient air temps, and that’s outside of my grow. If it was inside my warm humid grow room it would condensate like a fire sprinkler.

I’m not sayin that you would water cool your lights with that cool of a water temp, but if not, is there any point/environmental advantage/performance benefit? I mean you still gotta transfer the heat somewhere
As far as being environmentally advantageous.. Keeping the LEDs and other components (including the drivers, they do make water block\plates just for that purpose, btw!) cool should keep them from degrading, and ending up in a landfill sooner than later. Heat is the primary killer of electronics.. but then again, some components are specifically designed to operate at certain temps.


Performance wise.. Suppose you could over volt your water cooled LEDs and push a little harder, and boost the maximum output? I know my processors in my water cooled PCs sure benefit, with no condensation. From 2.7 to 4.5 Ghz, with a massive performance boost. Still stays under 65c too, and runs way quieter than an air cooler would..


Still gotta transfer the heat somewhere is right. Right into a big insulated water tank that can act like a mass storage battery, which you can then use another radiator loop to transfer all the heat that built up during the day back into the grow, during the night cycle. Or into the ground, etc? To another flip flopped room?
 

1212ham

Well-Known Member
It’s a cool idea, but I would be worried about condensation accumulating on your cooling pipes/heat sinks in your grow room. I’m guessing you would exchange the heat outside of the grow area, but the heat sinking taking place inside the grow would likely get drippy with condensation, without adequate insulation. Unless you are just using ambient air exchange with a fan radiator combo, which then I would question just how effective the heat transfer would be for all the extra hassle without some serious airflow, which then you have the fan wattage creating heat also. You’ll have to adjust the grow room air temperature anyways, so passive cooling/air exchange just seems to make more sense for economical purposes.

My point being is 1 Watt = 3.412 BTU/HR
no matter how you slice it. I’m not sure adding more watts to cool only your lights makes any sense, if it isn’t for a serious performance advantage. It would seem to make more sense to water cool the grow area to the desired canopy temp, and just have a large enough passive heat sink to keep the chips from getting too warm. Or cool everything with water, I don’t know. Just my thoughts
Well, cooler temps do increase the efficiency and life span of LED's
I grow in the winter and the heat is transferred to my living space, any power used by the fan helps heat it.
On the other hand, I don't know how practical it would be during the summer or in warm climates, I'd have to think about that.
 
Last edited:

Rocket Soul

Well-Known Member
As far as being environmentally advantageous.. Keeping the LEDs and other components (including the drivers, they do make water block\plates just for that purpose, btw!) cool should keep them from degrading, and ending up in a landfill sooner than later. Heat is the primary killer of electronics.. but then again, some components are specifically designed to operate at certain temps.


Performance wise.. Suppose you could over volt your water cooled LEDs and push a little harder, and boost the maximum output? I know my processors in my water cooled PCs sure benefit, with no condensation. From 2.7 to 4.5 Ghz, with a massive performance boost. Still stays under 65c too, and runs way quieter than an air cooler would..


Still gotta transfer the heat somewhere is right. Right into a big insulated water tank that can act like a mass storage battery, which you can then use another radiator loop to transfer all the heat that built up during the day back into the grow, during the night cycle. Or into the ground, etc? To another flip flopped room?
Just seems so much easier to just drive twice the leds at half current than getting into water cooling. If using 301 samsungs with decently old heatsink its just going to be a few degrees more than the sink. A fan on the back of a board sink also does wonders... And water sinking tends to make your light stay at the same height all the time, or be prone to leakage.
But i fully support any tinkering but not for me really. Unless i had like thousands of watts of high powered leds and could use the water for central heating :)
 

Drop That Sound

Well-Known Member
The quote is from another thread, but I think it fits here.

I suggest single row strips on 3/8" or 1/2" tube and possibly two row strips on 1/2". Something wider for multi row strips.

Several years ago I used Bridgelux EB Gen 2 on 1/2" square tube, very effective. They were recently removed and my GLA strips with 1/8" flat plate sinks were strapped on. You might be surprised how suddenly the air temp drops when the pump is turned on!

For strips, I'd love to find flat aluminum extrusion with a small water passage. Hmm, possibly small square tube attached to flat plate with Devcon F epoxy or thermal paste/adhesive... the wheels are turning... I have ideas!

I've been using distilled water, any ideas for a non toxic corrosion and bacteria inhibitor for aluminum?
1732221117889.png
 

Drop That Sound

Well-Known Member
I think those aluminum balusters ^ are pre drilled with a set of screw holes through on both ends, but could be filled back in with cheap alumaweld brazing rods, and capped off on the ends. Or tap some of the existing holes out a little bigger to add the fittings for the tubing to attach.

You can get longer ones for more $, but only 10 come in a box. Seams like it could be a better deal than buying regular square tubing. Thinner walls too, for better heat transfer and lighter weight. I like the rectangular dimensions better, being like 1/2" x 1" instead of 1x1, which is a waste and will take way more coolant to fill..

Otherwise, the cheapest I see for regular aluminum square tubing locally is $34 for a 1' x 96" stick, but aren't in stock and have to be ordered. Otherwise its over $40 for the ones in stock, which still only gets you two 4' channels to work with.

I would rather have a box of 10-15 balusters to make DIY aluminum water cooled LED strip water blocks for $60-80. Plus it comes with a fancy black anodized paint job..
 

Drop That Sound

Well-Known Member
For the thinner LED strips, they also have 1/2 x 1/2" aluminum baluster railing kits without the screw holes. Could easily stuff a 3/8 nipple fitting in each end and weld it in with the brazing rods. Thats what I'm using to make the frame on my new LED fixture I'm workin on. Got almost a full box at the "ReStore" building salvage center for $1! The fancy black ones :). Not using them for pumping coolant through though (I wish!), just for the framing.. to hold my screw in LED bulbs, lol.



Edit: The ones I got are 5/8”..

6533FD65-03F8-4804-A26A-CAA0A713581A.jpeg
 
Last edited:

Drop That Sound

Well-Known Member
3C366974-8B40-4824-BDD8-42C369C6685C.jpeg
My standard threaded PC water cooling fittings fit right in the end of the 5/8 aluminum stair railing picket channels. Barely much wiggle room or gaps to fill. The fittings are just nickel plated brass, so should be compatible when brazing it directly to the aluminum with alumaweld rods and a torch.

Maybe I’ll try it out sometime. I think Id rather go with wider LED strips though, on 1” square or preferably rectangular tubing. Weld little plates on the ends, then drill and tap the fittings in..
 
Top