Water cooled COBs

wietefras

Well-Known Member
What typically happens when you drop a hair dryer in a bathtub?
Yeah what happens when you do that?

Or even if it doesn't switch off:

Still, that's not even remotely the same. Even if all the water leaks out of the water cooling, it will be all over the floor and therefore nowhere near the electricity. So that would be more like throwing a bucket of water in the bathtub while holding a hair dryer in your hands.

That's why I'm asking seriously, what actually could go wrong.
 

mahiluana

Well-Known Member
Air cooling is just as effective as water cooling, each just have their strengths and weaknesses.

The whole water and electronics thing always makes me laugh though. Computers have been water cooled for decades...

Youre light should never be powered any time you are working on it... It really is that simple. Anyone who does that deserves the darwin award. (knocks on wood). lol
Sorry I`m new here ! But would you buy an aircooled car if you can get a watercooled ?
The last one I´ve seen was my fathers`peoplecar in 1968.
So I guess watercooled led light will be the future.
2 weeks ago I saw a 300 W watercooled lamp that store the energy in a watercube.
Then you can chose to heat the roots(ground in your growroom) - the shower - and with a big farm even your living room. For many growers it`s a problem to get out the heat off the growroom in summer - not with this lamp.
You can get back up to 60% of your eletricity-bill if you need hot water .
That led light only converts 10 % of the input in heat - is just a fairy tale.
 
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fearnoevil

Well-Known Member
So time for an update, I've been running my water-cooled proto-type for almost 2 months now and so far so good. I've got it hooked up to a 5-gal bucket with a fountain pump and as long as I keep a fan on the bucket, it keeps the water in the 70's (ambient temps are a little cool at 65F). The COB temp is runs from the 90's F to near 115 F so I believe with a better cooling system it'll run even cooler.

I've got 5 more tubes fabbed up and I decided to go to a smaller size - the rectangular aluminum tube dimensions are 2" x 4" x 4' with 1/8" wall thickness and they are considerably lighter than that monster prototype which was 2' x 6" x 4' and 1/4" thick (way too much, lol). I am about to order the COB's and drivers and hope to get them built over Christmas, if I didn't wait too late, lol. Here's a few pics ;?)
20161211_174500.jpg20161211_174535.jpg 20161211_174617.jpg 20161218_195334.jpg
 

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fearnoevil

Well-Known Member
Yeah, I know that, but this room is just being used for vegging, and it's right above the flowering room in the basement. The basement is unfinished so I have been diverting the forced air from that room downstairs to heat that area, and with the temps outside dropping to the low teens to sub-zero when these pics were taken, it's been cooler than normal to say the least.

But I'm not too worried, once I get everything cobbled together, I'm planning on installing a bypass so that the heat being removed from the light bars can be used to help heat the grow area. But the run-in period is going to take so time to dial in and control temps and rH, although I'm hoping it's easy enough transition. But it's definitly going to be a different animal than when I was venting the heat from 6 - 600w HPS lights and ballasts.
 

brewbeer

Well-Known Member
Wow great idea water cooling the array, I like it. I know a little about moving heat energy using water and I can attest that you can move a TON of heat with water using very little effort and almost no noise if you set it up correctly. The electricity/water concerns are easily managed with good light design and ground fault circuit interrupters @fearnoevil if you have any data from the smaller tube please post it. Also, do you know flow rates and fluid temperature changes across the bar? These would be great data to have.

My state just became legal and I'd like to set up a modest grow room. I have a 20 year old mh/hps but it would be way too hot for the small space I'd like to set up. Been researching LEDS and think diy cob build is the way to go, but still concerned about the heat. Was originally thinking passive heat sinks but the water cooled option is so intriguing. Even if you are running relatively warm water i would guess the ability to conduct heat away from the cob is still quite high. Does anyone have any data from running relatively warm water (say 60C/140F) under the cobs? At those temps it is easy to dissipate the heat outside the grow space.
 

ttystikk

Well-Known Member
Wow great idea water cooling the array, I like it. I know a little about moving heat energy using water and I can attest that you can move a TON of heat with water using very little effort and almost no noise if you set it up correctly. The electricity/water concerns are easily managed with good light design and ground fault circuit interrupters @fearnoevil if you have any data from the smaller tube please post it. Also, do you know flow rates and fluid temperature changes across the bar? These would be great data to have.

My state just became legal and I'd like to set up a modest grow room. I have a 20 year old mh/hps but it would be way too hot for the small space I'd like to set up. Been researching LEDS and think diy cob build is the way to go, but still concerned about the heat. Was originally thinking passive heat sinks but the water cooled option is so intriguing. Even if you are running relatively warm water i would guess the ability to conduct heat away from the cob is still quite high. Does anyone have any data from running relatively warm water (say 60C/140F) under the cobs? At those temps it is easy to dissipate the heat outside the grow space.
There's a thread link in my signature line. The modern water cooled COB LED era starts on page 129. I'd like to hear your thoughts.

Here's a link to the page;
https://www.rollitup.org/t/ttystikks-vertical-goodness.787572/page-129
 

majins

Well-Known Member
Been running my water cooled setup for 6 weeks now.
Need to figure out a way to stop the coolant loss. Dehumidifier manages to draw out the coolant even tho the res is air tight.
I guess I could keep topping it up tho since 6 weeks for 220ml loss isnt too bad.
 

visajoe1

Well-Known Member
Been running my water cooled setup for 6 weeks now.
Need to figure out a way to stop the coolant loss. Dehumidifier manages to draw out the coolant even tho the res is air tight.
I guess I could keep topping it up tho since 6 weeks for 220ml loss isnt too bad.
Is that possible? You have to have an air leak somewhere? Did you to a pressure test before filling with liquid?
 

Observe & Report

Well-Known Member
I use PVC line in my setup and water slowly evaporates out of it. Have to refill my reservoir annually. Most types of ordinary plastic will slowly let water vapor through, that's how Boveda packs work.
 

Shugglet

Well-Known Member
Was originally thinking passive heat sinks but the water cooled option is so intriguing. Even if you are running relatively warm water i would guess the ability to conduct heat away from the cob is still quite high. Does anyone have any data from running relatively warm water (say 60C/140F) under the cobs? At those temps it is easy to dissipate the heat outside the grow space.
Its all simply a function of how fast you can remove heat from the system vs how fast your light and pump are adding heat. The temperature then of the system will be more dependent upon ambient temperatures if you are using a radiator, as it will reach an equilibrium at (x) degrees above ambient temp. As long as your pumps can handle the heat, there is nothing wrong with running hotter water through your system.

Best ways to achieve a lower system would be to increase the amount of water in the system or increase airflow across / increase size of your radiator. Increasing the water flow does not significantly lower system temps. The lower your system temps, the more efficiently your cobs run.
 

visajoe1

Well-Known Member
Homeboy lost a whole cup, I think he'll live lol
Agree, small amount, completely manageble. Its just from my experience, or lackthereof?, in hvac. I dont fix the crap, Im the guy that sells the crap, then gets yelled at by the customer when it breaks. But I usually hear or can find out what the solution was if I want. I've just never seen an instance where a liquid in a sealed system or refrigerant within a system go missing without a leak existing somewhere . Its the investigator in me, now I'm curious and have to know. I'll ask my service guys tomorrow whats possible
 

ttystikk

Well-Known Member
Agree, small amount, completely manageble. Its just from my experience, or lackthereof?, in hvac. I dont fix the crap, Im the guy that sells the crap, then gets yelled at by the customer when it breaks. But I usually hear or can find out what the solution was if I want. I've just never seen an instance where a liquid in a sealed system or refrigerant within a system go missing without a leak existing somewhere . Its the investigator in me, now I'm curious and have to know. I'll ask my service guys tomorrow whats possible
I lose a little on a regular basis. It's not an emergency unless there's enough loss to affect performance.
 

Organic Miner

Well-Known Member
So hydronic uses a sealed system under pressure, are you guys doing that? I hear the word "reservoir " and sound like an open system subject to evaporation? I ask because I am thinking of going water cooled in my new place and I have been studying up water cooled hydronic systems to figure out all the pieces I need to put together.

It would be really nice if one you guys uploaded a diagram of your system to see how it's all plumbed together.
 

Shugglet

Well-Known Member
So hydronic uses a sealed system under pressure, are you guys doing that? I hear the word "reservoir " and sound like an open system subject to evaporation? I ask because I am thinking of going water cooled in my new place and I have been studying up water cooled hydronic systems to figure out all the pieces I need to put together.

It would be really nice if one you guys uploaded a diagram of your system to see how it's all plumbed together.
Theres a million ways to skin that proverbial cat. Why dont you share more info on what you want to achieve.
 
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