Is it possible to over cool COBs? Liquid cooling

TEKNIK

Well-Known Member
Great point, liquid cooling should have a sealed COB or other components, with one way ventilation of course
 

ANC

Well-Known Member
even a simple active CPU cooler keeps a COB remarkably cool.
Like a load cooler than what the average strips is run at.
 

TEKNIK

Well-Known Member
I actually want to see this guys liquid cooling system now. Please follow it through as I am genuinely interested in how it is going to work and how much better it will be
 

TEKNIK

Well-Known Member
I haven't learnt to navigate this forum too well yet. I really like liquid cooling and I can see it working great in a commercial environment. As far as hobby growers go it's far too expensive and difficult to get it right. But please try you may surprise me.
 

CobKits

Well-Known Member
short story: ttystiks was more work than he anticipated, ended up having to insulate all exposed parts and also blew some chips i believe due to condensation getting trapped under his lenses
 

Hadez411

Well-Known Member
Or run at 30w.. just run 2 parallel strings of 4 in series.
Two parallel strings would be another 240$, not looking to spend 700$ on only 480w of light. Even if it is 10% more lumens per watt than the strips, which would make it kind of like 520w equivalent to the strips, it still isn't very economical compared to strips at 435$/480w.

What would be the estimated lumens per watt you'd give a warm eb strip? From what I read there's typical about 10% drop in lumens from 25c to 80c operating temps. So I'm assuming the EBs at 1A would be somewhere around 160 lm/W if, as the manual says, they're at 175 lm/W at 25c.

That's where I like the cobs, they don't seem to mind running low amperage (1a) and fairly high temps while outputting 180'ish lumens per watt.
 
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Airwalker16

Well-Known Member
Two parallel strings would be another 240$, not looking to spend 700$ on only 480w of light. Even if it is 10% more lumens per watt than the strips, which would make it kind of like 520w equivalent to the strips, it still isn't very economical compared to strips at 435$/480w.

What would be the estimated lumens per watt you'd give a warm eb strip? From what I read there's typical about 10% drop in lumens from 25c to 80c operating temps. So I'm assuming the EBs at 1A would be somewhere around 160 lm/W if, as the manual says, they're at 175 lm/W at 25c.

That's where I like the cobs, they don't seem to mind running low amperage (1a) and fairly high temps while outputting 180'ish lumens per watt.
No... You're driver runs 4 cobs right? So make 2 series strings of 4, and connect them in parallel. It halve the CC driver current for you
 

Hadez411

Well-Known Member
No... You're driver runs 4 cobs right? So make 2 series strings of 4, and connect them in parallel. It halve the CC driver current for you
I have two 240w drivers running 4 cobs each at 60w for a total system of 480w. Vero 29D is 30$CAD. Adding 8 more to the 8 I already have is adding 240$ more to my system. I'm trying to be economical, not reach for the utmost efficiency without any thought about the cost.

Even if we're taking about each 240w unit, that's 240$ for the 8 cobs and 105$ for the power supply.

Long story shart, eb strips are back in stock in 3 days and this was a waste of my time and some shipping fees.
 

1212ham

Well-Known Member
I haven't learnt to navigate this forum too well yet. I really like liquid cooling and I can see it working great in a commercial environment. As far as hobby growers go it's far too expensive and difficult to get it right. But please try you may surprise me.
My 180w strip light wasn't difficult or expensive. I TIG welded 1/2" square tubes to 1/2" square headers, bought an $10 pump off eBay and used a plastic tote for a reservoir.

I also tested a Citizen COB at 250W on a $6 CPU water block . With good water flow, junction temp was only slightly higher than water temp. Voltage would stabilize in a less than a second after power on.
 
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ApfelStrudel

Well-Known Member
I'm using Arctic Cooling Freezer 64 lp heatainks for cooling CXB3070 at 1.9-2.1A (whatever the driver puts out at certain temperature). Picked those for the ease of mounting. You can put your finger on the copper base if the heatsink or base if the cob at any given time and you'll barely feel any warmth.

798a297da9d54915008dbbb47957a119.png ACfreezer64LP_d.jpg
IMG_20181118_205235_819.jpg

Remove the already applied thermal paste and clean it with iso then glue the cob with some arctic silver adhesive or go even crazier and reflow the cob to the copper base with some S-bond

I got those brand new at $10 a pop, copper footprint is 35x35mm
 

Airwalker16

Well-Known Member
I'm using Arctic Cooling Freezer 64 lp heatainks for cooling CXB3070 at 1.9-2.1A (whatever the driver puts out at certain temperature). Picked those for the ease of mounting. You can put your finger on the copper base if the heatsink or base if the cob at any given time and you'll barely feel any warmth.

View attachment 4307796 View attachment 4307798
View attachment 4307799

Remove the already applied thermal paste and clean it with iso then glue the cob with some arctic silver adhesive or go even crazier and reflow the cob to the copper base with some S-bond

I got those brand new at $10 a pop, copper footprint is 35x35mm
Damn those are some quality sinks. Where the hell did you get them so cheap??
 

Airwalker16

Well-Known Member
I'm using Arctic Cooling Freezer 64 lp heatainks for cooling CXB3070 at 1.9-2.1A (whatever the driver puts out at certain temperature). Picked those for the ease of mounting. You can put your finger on the copper base if the heatsink or base if the cob at any given time and you'll barely feel any warmth.

View attachment 4307796 View attachment 4307798
View attachment 4307799

Remove the already applied thermal paste and clean it with iso then glue the cob with some arctic silver adhesive or go even crazier and reflow the cob to the copper base with some S-bond

I got those brand new at $10 a pop, copper footprint is 35x35mm
Do you have a pic of the other end of the pipes? Like do they just go through the 2 sinks, spaced out evenly? Pinched off like the other sides?
 

TEKNIK

Well-Known Member
That's a heatpipe cooler, it's all sealed, the pipes are a sealed unit and they bend them into shape. He purchased that really cheap.
 

ANC

Well-Known Member
Never underestimate the creativity of a pot smoker., CPU cooler is like $10.

AS someone who has overseen a pretty large (for a personal grower) COB grow, I would recommend building in simple cheap NC thermal fuses inline with the power cord and connected to the heatsink for any active cooling.
 
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