DIY COB MINERAL OIL HEAT SINK

oill · Jul 3, 2015

wassup.

I have been running a 600w hps, and love it. Perfect for 3 plants in a 3x3 area. I could maybe to 4x4.

I have been looking at making my own cob light and I have a few questions.

1. Do I use colored lights or just cool and warm whites from brigelux?

2. How many would I need for a 600w equivalent? Woukd it be 6 lights and if so... Woukd that save any power?

3. I was thinking of mounting to a aluminium container and filling that with mineral oil to deal with the heat as opposed to using heat sinks and fans.... Any thoughts?

Ta

borbor · Jul 3, 2015

The mineral oil thing has briefly occured to me, but how freakin' heavy can you stand your light being?
It'd probably turn out at worst as a mess and at best as something that looks cool and different, that achieves the same results others do but requiring more work and possibly $

alesh · Jul 3, 2015

oill said:
wassup.

I have been running a 600w hps, and love it. Perfect for 3 plants in a 3x3 area. I could maybe to 4x4.

I have been looking at making my own cob light and I have a few questions.

1. Do I use colored lights or just cool and warm whites from brigelux?

2. How many would I need for a 600w equivalent? Woukd it be 6 lights and if so... Woukd that save any power?

3. I was thinking of mounting to a aluminium container and filling that with mineral oil to deal with the heat as opposed to using heat sinks and fans.... Any thoughts?

Ta

1. Warm white from Bridgelux or Cree seems to be working well.
2. Depends on how efficient setup you put together. I'd say that 300W of CXB3590 run very soft could be a serious competition for a 600W HPS.
3. Not worth it IMO.

oill · Jul 3, 2015

alesh said:
1. Warm white from Bridgelux or Cree seems to be working well.
2. Depends on how efficient setup you put together. I'd say that 300W of CXB3590 run very soft could be a serious competition for a 600W HPS.
3. Not worth it IMO.

borbor said:
The mineral oil thing has briefly occured to me, but how freakin' heavy can you stand your light being?
It'd probably turn out at worst as a mess and at best as something that looks cool and different, that achieves the same results others do but requiring more work and possibly $

So I'm trying to avoid loads more fans. I was thinking I could use a single long heat sink and enclose it. Then I would use my exhaust fan to pull air over the heat sink with one of these adapters....

http://m.buyspares.co.uk/product.pl?pid=1232549&utm_source=google&utm_medium=base&utm_campaign=products&mkwid=ATVQv3iS&pcrid=55040302709&pdv=m&gclid=CIGjvIi-v8YCFe7KtAod7u4O0A

PurpleBuz · Jul 3, 2015

oill said:
So I'm trying to avoid loads more fans. I was thinking I could use a single long heat sink and enclose it. Then I would use my exhaust fan to pull air over the heat sink with one of these adapters....

http://m.buyspares.co.uk/product.pl?pid=1232549&utm_source=google&utm_medium=base&utm_campaign=products&mkwid=ATVQv3iS&pcrid=55040302709&pdv=m&gclid=CIGjvIi-v8YCFe7KtAod7u4O0A

KISS

a single long heat sink is a good way to go, enclosing it is bad since it traps heat and you lose most of the passive cooling capability of the heat sink. Best designs I have seen are using low powered, hi efficiency computer fans that fit the heat sink well. Amazing how little fan power is actually required to keep a heat sink close to grow room temperature.

I'm currently using 2 rosewill hyperborea fans that fit the width of my heatsink on a 1 meter long heatsink. http://www.amazon.com/Rosewill-ROCF-11004-Hyperborea-120mm-Case/dp/B006DKEQV0/ref=sr_1_1?ie=UTF8&qid=1435948455&sr=8-1&keywords=rosewill hyperborea

oill · Jul 3, 2015

PurpleBuz said:
KISS

a single long heat sink is a good way to go, enclosing it is bad since it traps heat and you lose most of the passive cooling capability of the heat sink. Best designs I have seen are using low powered, hi efficiency computer fans that fit the heat sink well. Amazing how little fan power is actually required to keep a heat sink close to grow room temperature.

I'm currently using 2 rosewill hyperborea fans that fit the width of my heatsink on a 1 meter long heatsink. http://www.amazon.com/Rosewill-ROCF-11004-Hyperborea-120mm-Case/dp/B006DKEQV0/ref=sr_1_1?ie=UTF8&qid=1435948455&sr=8-1&keywords=rosewill hyperborea

I take your point, but my idea is more simple. There would be a channel over the single heat sink. The extractor fan would pull enough air over the heat sink. My extractor is also temp controlled. This way i don't need a cpu power supply to power pc fans. It's all covered by me extractor fan just like a cool tube for an hps works. You get the idea?

PurpleBuz · Jul 3, 2015

I understand, Doesn't sound simpler to me, its less than $30 parts for two fans and a power supply, but if it works for you and you can integrate the grow room ventilation that's cool.

420Sm0keWeedEveryday · Jul 5, 2015

Enclosing your heat sink in a coolant, without also incorporating a pump and radiator, will cause the heat sink to not work. The way you dissipate heat across a temperature gradient efficiently, is through increasing surface area. By encasing the fins on the heat sink you lose most of the surface area that had contact with a temperature gradient.

420Sm0keWeedEveryday · Jul 5, 2015

Try using antifreeze with an anticorrosive additive along with a high flow/pressure pump and a car radiator or heater core. Probably will still need a fan, but it could be run at low speed and would likely provide more cooling capacity than a simple air cooled heatsink.

PurpleBuz · Jul 5, 2015

420Sm0keWeedEveryday said:
Try using antifreeze with an anticorrosive additive along with a high flow/pressure pump and a car radiator or heater core. Probably will still need a fan, but it could be run at low speed and would likely provide more cooling capacity than a simple air cooled heatsink.

yes but at what cost ? these are led cobs, with most people trying to underdrive for efficiency. The concentrated point high heat source just isn't present unlike an HID system or a tightly enclosed overdriven gaming computer.

bicit · Jul 5, 2015

PurpleBuz said:
yes but at what cost ? these are led cobs, with most people trying to underdrive for efficiency. The concentrated point high heat source just isn't present unlike an HID system or a tightly enclosed overdriven gaming computer.

Depends on your situation. If you're in a insulated and sealed room for example, you'll need some way to remove the heat. Water cooling the cobs is a good way to directly remove the heat and displace it someplace else, reducing AC loads. Water cooling LED's is a bit of a specialized tool in a way. It's only viable in a few situations.

oill said:
I take your point, but my idea is more simple. There would be a channel over the single heat sink. The extractor fan would pull enough air over the heat sink. My extractor is also temp controlled. This way i don't need a cpu power supply to power pc fans. It's all covered by me extractor fan just like a cool tube for an hps works. You get the idea?

How about sizing you heat sink to be adequate to function passively /semi passively and simply place a carbon filter over top directly. That way you don't add unnecessary back pressure on your fan and won't have to worry about a fan failure of any sort.

Rahz · Jul 5, 2015

oill said:
So I'm trying to avoid loads more fans. I was thinking I could use a single long heat sink and enclose it. Then I would use my exhaust fan to pull air over the heat sink with one of these adapters....

http://m.buyspares.co.uk/product.pl?pid=1232549&utm_source=google&utm_medium=base&utm_campaign=products&mkwid=ATVQv3iS&pcrid=55040302709&pdv=m&gclid=CIGjvIi-v8YCFe7KtAod7u4O0A

Pound for pound radial heat sinks perform the best without fans. Problem is sourcing them for a reasonable price. You can find radials on Ebay listed as 50W Watt LED Aluminium Heatsink and bid $12 in bulk w free shipping. They work very well for 25 watt output or less (around 15 watts of heat). Feasable for up to 20 watts of heat with slight performance drop. There are also 100w versions that would probably do a good job dissipating 30 watts of heat, but are more expensive of course.

The strategy a lot of peeps here use is to get a bar heatsink from heatsinkusa and go "semi-passive". Oversize the heatsink a bit and use a single fan on up to 200 watts output to keep things cool. If the fan fails the heatsink will still get the job done til repairs are made with a slight loss of performance. Unless you're getting really crazy with effeciency desires you can build something nice in the 400w range using 2 fans that will compete with a 600w HPS, though I would recommend a bit more so as to kick the HPS ass so to speak.

420Sm0keWeedEveryday · Jul 6, 2015

Not saying a watercooling loop is necessary for most of the heat loads discussed on this forum. I just would hate to see him go through all the trouble of enclosing a heat sink and covering it in mineral oil. That type of setup just won't be as effective as leaving the heat sink passively air cooled. A watercooling loop could be built to handle a much larger load if that's what he's looking for.

oill · Jul 6, 2015

420Sm0keWeedEveryday said:
Not saying a watercooling loop is necessary for most of the heat loads discussed on this forum. I just would hate to see him go through all the trouble of enclosing a heat sink and covering it in mineral oil. That type of setup just won't be as effective as leaving the heat sink passively air cooled. A watercooling loop could be built to handle a much larger load if that's what he's looking for.

Rahz said:
Pound for pound radial heat sinks perform the best without fans. Problem is sourcing them for a reasonable price. You can find radials on Ebay listed as 50W Watt LED Aluminium Heatsink and bid $12 in bulk w free shipping. They work very well for 25 watt output or less (around 15 watts of heat). Feasable for up to 20 watts of heat with slight performance drop. There are also 100w versions that would probably do a good job dissipating 30 watts of heat, but are more expensive of course.

The strategy a lot of peeps here use is to get a bar heatsink from heatsinkusa and go "semi-passive". Oversize the heatsink a bit and use a single fan on up to 200 watts output to keep things cool. If the fan fails the heatsink will still get the job done til repairs are made with a slight loss of performance. Unless you're getting really crazy with effeciency desires you can build something nice in the 400w range using 2 fans that will compete with a 600w HPS, though I would recommend a bit more so as to kick the HPS ass so to speak.

bicit said:
Depends on your situation. If you're in a insulated and sealed room for example, you'll need some way to remove the heat. Water cooling the cobs is a good way to directly remove the heat and displace it someplace else, reducing AC loads. Water cooling LED's is a bit of a specialized tool in a way. It's only viable in a few situations.

How about sizing you heat sink to be adequate to function passively /semi passively and simply place a carbon filter over top directly. That way you don't add unnecessary back pressure on your fan and won't have to worry about a fan failure of any sort.

Thanks for the input guys. It's helping shape the thinking for sure.

So at the moment I am still thinking..

2 x 80mm long heat sinks (100mm with the ends chopped off so that it fits in the tent)

6 x cxa3590's or vero bxrc-30g10k0-l-03

I'm in UK. What woukd be a good driver for these? Can I drive all 6 with one driver?

The cooling fan is still yet to be decided. I still like the extractor fan pulling over the heat sink idea. Would need to make sure that the "tunnel" is the same size in order to not get negative pressure on the fan. I have an awesome extractor that is heat controlled so I think it's a good way to go. There wont be co2 added to the tent.

oill · Jul 7, 2015

420Sm0keWeedEveryday said:
Try using antifreeze with an anticorrosive additive along with a high flow/pressure pump and a car radiator or heater core. Probably will still need a fan, but it could be run at low speed and would likely provide more cooling capacity than a simple air cooled heatsink.

Might just use my car... Just drive it into the house.

skunkd0c · Jul 7, 2015

Are you really going to put a led in cooking oil, like the guy with his pc in cooking oil ?
i have been waiting so long for someone to be brave/stupid enough to suggest this
you're awesome man if its true and not just some pipe dream

oill · Jul 8, 2015

skunkd0c said:
Are you really going to put a led in cooking oil, like the guy with his pc in cooking oil ?
i have been waiting so long for someone to be brave/stupid enough to suggest this
you're awesome man if its true and not just some pipe dream

There is a dude on youtube already. Looks like it works. If you cook your food in mineral oil maybe it's effected your brain buddy.

skunkd0c · Jul 8, 2015

oill said:
If you cook your food in mineral oil maybe it's effected your brain buddy.

If you're going to be a smart arse you should try to be grammatically correct too imo

For future reference , you should of used the word "affected" not effected*
Effected means "executed, brought about, produced something."
Affected means "impacted, created an affect on, changed in a certain way."

Your sentence actually reads "mineral oil created skunkd0c's brain or caused his brain to come into existence"
I do not believe this is what your wanted to convey

Nice video btw .. educational

PurpleBuz · Jul 8, 2015

I can imagine building a small oil chamber to house a single cob out of anodized aluminum, and then bonding a standard aluminum heat sink to carry the heat away. That would take advantage of the thermal transfer efficiency of immersing the cob directly in oil. The mineral oil container would have to be sealed 100% since leakage or contamination would probably fry the cob.

oill · Jul 8, 2015

skunkd0c said:
If you're going to be a smart arse you should try to be grammatically correct too imo

For future reference , you should of used the word "affected" not effected*
Effected means "executed, brought about, produced something."
Affected means "impacted, created an affect on, changed in a certain way."

Your sentence actually reads "mineral oil created skunkd0c's brain or caused his brain to come into existence"
I do not believe this is what your wanted to convey

Nice video btw .. educational

Yeah your right... Affected. It's definitely affected... And this is the effect...

DIY COB MINERAL OIL HEAT SINK

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