Liquid Cooled 8 COB Cabinet

bicit

bicit

Well-Known Member
Doer said:
I've seen cold plates that are spec for mineral oil. It is a bit more costly to pump around.
Click to expand...
I guess it depends on the application. Mineral oil is more stable for sure. But it's more viscous thus requiring a beefier pump. It's also pretty costly to buy compared to purified water.

I think water would be a better choice for this scenario
 
a senile fungus

a senile fungus

Well-Known Member
I saw a video on YouTube and the mineral oil maintained convection currents throughout. The oil nearest the exterior of the container was the coolest (in this case mason jars) and the warmer oil in the center would rise.

DIY 100 WATT COD LED MINERAL OIL COOLED, LED RUNNING TEMPS,STEMS LOWER PH:

But then again, researching further shows that mineral has a thermal conductivity of around 0.1w/mK and water at 0.54w/mK.

Water
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

Mineral oil
http://forums.anandtech.com/showthread.php?t=1477783

I only took physics, didn't excel in it, but a higher thermal conductivity is better for this.

Edit: haha maybe shoulda read a bit more before jumping in, the thermal capacity of mineral oil and it's failings have already been discussed earlier in the thread.
 
Sxott

Sxott

Well-Known Member
Running into issues. Since I had to order a min of 10 xcb3070, this cabinet may become a 10 cob cabinet.
I have been scouring the internet looking for a HLG-185H-C1400A or B and everything seems to be on a big back order. (was going to save the 2 extra)
So now my idea is to use all 10 and run 5 cobs each a HLG-185H-C1050B. 10@1.05 amps will give me within 1500 lumens of 8@1.4 (and 34 less watts)
Does anybody see any issues with this? How much cooler would this cabinet be?

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2189337_-1
 
Sxott

Sxott

Well-Known Member
Observe & Report said:
Since you already had to front the money for the extra chips, go for 10@1 amp, depending on what you pay for electricity you'll come out ahead after a few years. I doubt you'll see any difference in growth but I'm not an expert.
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The HLG-185H-C1050B Im talking about is 1 amp. Well 1.05 amps. It goes up to 190 volts. But 5 of these chips are only about 173 in series. I hope it does not lose very much efficiency by running it below its max.
 
C

churchhaze

Well-Known Member
Sxott said:
The HLG-185H-C1050B Im talking about is 1 amp. Well 1.05 amps. It goes up to 190 volts. But 5 of these chips are only about 173 in series. I hope it does not lose very much efficiency by running it below its max.
Click to expand...
That's a pretty good driver and cob combination. I don't think you'd lose any driver efficiency.. You'd be running it at 91% load capacity anyway, so I'm sure you'd get 94% efficiency.

1.05A is a great balance between efficiency and startup cost... and if you can get top bin, your lamp will be very good efficiency.
 
bicit

bicit

Well-Known Member
elektrician said:
if the liquid is still in questions for this setup, id like to through in baby oil, no electrical connectivity, and its been used for fully submerged server setups.
Click to expand...
Same thing as mineral oil, electrical conductivity isn't really a problem in this instance. Wouldn't really want to submerge the cob. If you think the light loss from a lens is bad...
 
Sxott

Sxott

Well-Known Member
Alright.. Got the 2 HLG-185H-C1050B ordered from Jameco. Looks like Ill be running an even spead or around 60,740 lumens @ 166 Lm/watt :) Im so friggin stoked to have found all this info here and making the move. This is one of a bunch of cabinets I will be making. Hopefully the 1000 HPS are a thing of the past.
Im eyeballing the cxb3590s for my next build.
Can somebody send me a link to a place where I can get COB holders that will fit my chips. Solderless would be great but I can solder if I have to. trying to make maintenance and upgrading easy.
Now that I have dropped the amps, Is passive cooling an easily doable option?
 
nogod_

nogod_

Well-Known Member
If you are trying to cool 2x180w passively you will need two pretty massive heatsinks. Something like 2 x 40" of the 12" profile. Going to be a bummer to ship.

Just use 3' of the 5.886" and put a 6" case fan on top.

Sxott said:
Alright.. Got the 2 HLG-185H-C1050B ordered from Jameco. Looks like Ill be running an even spead or around 60,740 lumens @ 166 Lm/watt :) Im so friggin stoked to have found all this info here and making the move. This is one of a bunch of cabinets I will be making. Hopefully the 1000 HPS are a thing of the past.
Im eyeballing the cxb3590s for my next build.
Can somebody send me a link to a place where I can get COB holders that will fit my chips. Solderless would be great but I can solder if I have to. trying to make maintenance and upgrading easy.
Now that I have dropped the amps, Is passive cooling an easily doable option?
Click to expand...
 
Sxott

Sxott

Well-Known Member
Update:
Im sorry to report that this will not be liquid cooled after all :( Over the past week I have came up with several design ideas for liquid cooling. All of them seem to be more complex than I would like and should a part fail, it could fry my spendy little chips and plants.

Here is the new idea:
I ordered a 1/4" x 16 1/4" x 48 5/8" big honkin piece of aluminum plate that I found a good deal on. I also ordered 20 cpu heatsinks (no fan) that I got a great deal on by ordering 20 of them. I will be drilling and tapping the 1/4 plate for the cob holders on the bottom of the plate and doing the same thing with the heatsinks above the chips on top of plate. Imagine I will only need 10 but Ill put the extra 10 on if need be. The whole light will be mounted in the top of cabinet and will pull air from the front top of cabinet , over the heatsinks, and out the back. I will have PC fans across the back of the cab. Maybe some ceramic paint underneath by the chips to further insulate it from the top heat. I will prob mount the drivers inside on the top of plate also in case I ever pull it out to use outside cab. Another thing is this design will also help keep the light inside the cab.

cpucooler.jpg newtopside.jpg
 
salmonetin

salmonetin

Well-Known Member
...i saw info about watercooling... ...its a expensive way to my eye... .

...but i like the info about watercooling... ...not only for leds...

...and lot of times i look in comercial solutions for inspiration... or look about general prices...

...the link(s) its only for examples or ideas... ...not for buy nothing...

https://www.youtube.com/playlist?list=PLC6EA48744A9A954D

...inspirative for a diy way... but expensive way (with pc parts) to my eye too...

:peace:

...sorry for my bad english....

saludos
 
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bicit

bicit

Well-Known Member
salmonetin said:
...i saw info about watercooling... ...its a expensive way to my eye... .

...but i like the info about watercooling... ...not only for leds...

...and lot of times i look in comercial solutions for inspiration... or look about general prices...

....i dont want to nobody buy nothing... ...im only looking for good info...

...the link(s) its only for examples or ideas...

https://www.youtube.com/playlist?list=PLC6EA48744A9A954D

:peace:

saludos
Click to expand...
Large scale commercial operations could probably make good use of it. Directly cooling the cobs with chilled water would be more efficient than cooling the air around HID bulbs. Greenhouses, who may already have a large water chiller unit would greatly benefit. Large indoor warehouses as well, esp in areas with high ambient temperatures that AC is required just to maintain 'room temp'. Indeed water cooling cobs has many interesting possibilities.

Not so practical for the smaller grower in a tent or a closet. Passive cooling would be the way to go there.
 
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