Water cooled cobs

shimbob

Well-Known Member
It's been running for over 24 hours now, hasn't burned down the house so looks like a success!

4 cxb3590 5000k (it's a pure veg light),
EGL-200-C2100A meanwell driver
4 generic copper water blocks
radiator, reservoir, pump, fan
And the rest of the plumbing.

Only been running it at the lowest driver settings and the water remains no higher than room temperature. Will crank it up once the plants are ready.
 

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shimbob

Well-Known Member
The Killawatt says...

Measuring only the pump at the lowest setting and the fan, they consume 16watts. Crank the pump to max and they consume 40watts. I'm using a recycled 300watt PC power supply, no doubt very inefficient at such low load.

The driver is currently on 120v due to me being lazy, 240v is available and I'll make the switch later. On 110v and at the lowest setting, killawatt says it's consuming 60w. Cranked up to max it consumes 160w.
 

CobKits

Well-Known Member
in most cases water cooling is a wash

simple things like:
-using 240V on the driver
-passive cooling on heatsinks
-subbing more efficient chips than CXB for the same price

would be ultimately more reliable, efficient, cost effective, and easier to build
 

shimbob

Well-Known Member
in most cases water cooling is a wash
You're right it's definitely a niche thing. My desire to build it came after we used a Cirrus 1K led light in a 4x4 tent, with poor air flow and without AC, during the summer. Dreadful heat issues. You can see inside the 1K light that they use what appears to be bog-standard PC cpu coolers. So I told the girlfriend that some day I'll rip the 1K apart and replace the coolers with water blocks, but she asked me to build a prototype first. So, voila!

My final design would have 4 of these boards, for a total of 16 cobs in a 4x4 tent. I sized the radiator, reservoir, and pump for the full build. But lately I've thinking strips instead, so... I'm interested in building a mini grow room inside an antique fridge or the 42U server rack sitting in my garage. These lights will probably end up in there.

Nice use of the AIO water cooler for that mini tent!
 

dabby duck

Well-Known Member
You're right it's definitely a niche thing. My desire to build it came after we used a Cirrus 1K led light in a 4x4 tent, with poor air flow and without AC, during the summer. Dreadful heat issues. You can see inside the 1K light that they use what appears to be bog-standard PC cpu coolers. So I told the girlfriend that some day I'll rip the 1K apart and replace the coolers with water blocks, but she asked me to build a prototype first. So, voila!

My final design would have 4 of these boards, for a total of 16 cobs in a 4x4 tent. I sized the radiator, reservoir, and pump for the full build. But lately I've thinking strips instead, so... I'm interested in building a mini grow room inside an antique fridge or the 42U server rack sitting in my garage. These lights will probably end up in there.

Nice use of the AIO water cooler for that mini tent!
I was just going to reply, cool as fuck, equally as niche.
But the effect is kinda like exotic car builders who are ahead of their time and even if the direct technology isnt used, usually in the future these guys/gals pushed it.
Porsche built a battery car in the 1890s and Duesenberg built a blown dual overhead cam 4 valve motor before the 1920's, both considered very niche in their time and now just about every ic engine mimics this design and battery powered cars are on the comeback as well.

Personally, cool as hell to see people push what is possible.
 

shimbob

Well-Known Member
The aliexpress radiator came dented with a pinhole leak, jbweld to the rescue.

A real challenging part was finding the right combination of tubing, tees, splitters and reducers to go from the 1/2" pump to the whatever-sized water blocks, and while multiplexing the water so the blocks are all in parallel.

Switched over to 220, still not burning the house down. We just moved, I have no idea where my ammeter is.
 

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Chip Green

Well-Known Member
How are you guys recovering the heat watts? Or is it still just wasted.
There is somebody around here, name has escaped me now.....Runs a water cooled cob system that maintains the hot water service in his home....

Ive considered a water cooled VEG light, to warm the clone trays. Since I'm on a small scale it didn't really seem worth it....
 

shimbob

Well-Known Member
How are you guys recovering the heat watts? Or is it still just wasted.
When i started designing this kit before we moved, I was very interested in dumping the heat into the house crawlspace during the cold winter months. Alas, now our grow is detached from house.

Quick and dirty measurement, measured the lights with a Lux app on my phone(ya ya, terrible units to use). Measuring dead center of the fixture it maxes out at 8000lux until I'm more than 3 away and it starts dropping off. Probably maxed out a 13bit sensor (2^13=8192). I'll be able to borrow a proper light sensor later.
 

shimbob

Well-Known Member
Cranked it up full blast, still can't find my ammeter but here are some other numbers for the number lovers.
Ambient air temperature 18.6C
Radiator fan exhaust temperature 20.1C
Water temperature 71F (+- 2F, it's a kitchen-grade thermometer for the oven)
Vout of the driver 68.7v
Some slight variation of the voltage at the cobs: One pair of cobs in series has the two cobs at 34.3v and 33.7v, other pair in series has 33.8v and 34.2
 

skoomd

Well-Known Member
In my experience water cooling PCs, watercooling is just another headache to deal with unless you're using a closed loop setup like @The Dawg is using (is that a corsair H100i you're using?). Leaks do happen more than you'd think, and water + high voltage/high current lights/fans/etc is a bad time.

I believe you can use non conductive coolants like PG or something, but it's less effective at transferring heat than plain ol' H2O.
 

ttystikk

Well-Known Member
Cranked it up full blast, still can't find my ammeter but here are some other numbers for the number lovers.
Ambient air temperature 18.6C
Radiator fan exhaust temperature 20.1C
Water temperature 71F (+- 2F, it's a kitchen-grade thermometer for the oven)
Vout of the driver 68.7v
Some slight variation of the voltage at the cobs: One pair of cobs in series has the two cobs at 34.3v and 33.7v, other pair in series has 33.8v and 34.2
Take your temperature readings after things have been running for an hour or two.
 

The Dawg

Well-Known Member
In my experience water cooling PCs, watercooling is just another headache to deal with unless you're using a closed loop setup like @The Dawg is using (is that a corsair H100i you're using?). Leaks do happen more than you'd think, and water + high voltage/high current lights/fans/etc is a bad time.

I believe you can use non conductive coolants like PG or something, but it's less effective at transferring heat than plain ol' H2O.
Its A Cooler Master 240 :hump:
 
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