Heatsinks for DIY LED lamps

Abiqua

Well-Known Member
I knew it wasn't just laziness on my part! cleaning/wiping is all I have ever done!
I did this with my last two heatsinks, which are Used laptop cpu coolers straight from the 'bay. Both had copper pads, with scratching but no large gouges. Swabbed it with ISA, threw down the PK2, vero 10 and then kapton. No hiccups. Obviously a lower voltage/wattage, but the lights run excellent in the veg chamber, no abnormal heating issues whatsoever, in fact, they seem to run cooler than my estimated Ta, so that should be a + .........:peace:
 

SupraSPL

Well-Known Member
I ordered 3 of these heatsinks from China to use with 2 VERO18 per sink @1050. (dimmable) According to the sellers description, it should be enough to work passively. We shall see...

The price for the sinks is good until you add the shipping. Still cheaper than HSUSA.
http://www.lck-led.com/aluminum-heatsink-20x3w-50x1w-400x120x20mm-black-p-1111.html?cPath=152_185
Great find ellydee :leaf: I have done business with LCK before and they are solid. I put these heatsinks in the spreadsheet and I agree, they are competitively priced even with shipping. They do have thin bases though, not sure they would work well with large COBS. Don't forget LCK discount code 12% off: CPFer

LCK heatsinks.png

HUSA 4.85", very similar profile. This is the total price shipped for a 12" piece
HUSA 4.85 X 12.png

They also sell Cree XPL for a fair price, although there is a typo the 7A3 warm white is a U5 bin not a V5 bin.
 
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Bueno Time

Well-Known Member
Impressive the cooling you got from a small fan. What 50mm fan was that ? How many watts was it drawing ? Trying to get a handle on how much air flow is going through the heatsink....
The fan sticker on it says .1A 8cfm just tested using it on an old 12v supply for a Remington electric shaver that died on me a couple years ago, actually its the power supply for my DIY colloidal silver gen. Im sure its not the most efficient supply, I plan to use a MW LPV-35-12 for the 12v supply also not that efficient only 84% but should have MW reliability and only $15 is fairly reasonable.

Kill-A-Watt
One 50mm on Remington 12v supply .56PF 1.6w .02A
Two 50mm on same supply .60PF 3.2w .04A

Kinda surprised they pull 1.6w each at 12v.

The fans were 50mm x 50mm x 10mm for $2 each off ebay, I just saw some 50mm x 50mm x 20mm that are rated at 14.6cfm, the fan blades are twice as wide as what I got but they want $3.30 each for those fans.
 
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Imptspd

Well-Known Member
So I've read through this entire thread and can't grasp some aspects for passive cooling. But from what I'm now thinking, from the graphs on page 1, the 10.00" profile from Hsu should effectively dissipate 4.25 watts per inch of cut length. Is this correct?
 

PurpleBuz

Well-Known Member
The fan sticker on it says .1A 8cfm just tested using it on an old 12v supply for a Remington electric shaver that died on me a couple years ago, actually its the power supply for my DIY colloidal silver gen. Im sure its not the most efficient supply, I plan to use a MW LPV-35-12 for the 12v supply also not that efficient only 84% but should have MW reliability and only $15 is fairly reasonable.

Kill-A-Watt
One 50mm on Remington 12v supply .56PF 1.6w .02A
Two 50mm on same supply .60PF 3.2w .04A

Kinda surprised they pull 1.6w each at 12v.

The fans were 50mm x 50mm x 10mm for $2 each off ebay, I just saw some 50mm x 50mm x 20mm that are rated at 14.6cfm, the fan blades are twice as wide as what I got but they want $3.30 each for those fans.
thanks for the info.... incredible what a tiny little fan like that can do
 

bicit

Well-Known Member
Cell phone chargers are great power supplies for fans. Most I've discovered in the junk drawer are 5v, 1000ma, constant voltage. Tablet USB chargers or dual outlet USB chargers can be rated up to 2000ma.

So I've read through this entire thread and can't grasp some aspects for passive cooling. But from what I'm now thinking, from the graphs on page 1, the 10.00" profile from Hsu should effectively dissipate 4.25 watts per inch of cut length. Is this correct?
yup, I get between 4 watts with 110cm^2 of surface area per watt, or 5 watts with 90cm^2 of surface area per watt. However it's one of the more expensive profiles they have available at 130cm^2/$
 
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nomofatum

Well-Known Member
There are too many pages for me to look though, did anyone ever just use water cooling and much smaller heat sinks with no fans, just water heat blocks? It should be even more effective than large heat-sinks with fans and potentially cheaper. Also a bonus is you can put your radiator and pump outside the room so you aren't blowing heat around the grow area.
 

Imptspd

Well-Known Member
Thank you bicit.
From what I calculated from the charts on page 1 was:
Profile--surface area at 1"cut length-- watts disipation per cut inch capability.
2.060"=84.43cm^2=0.768w
3.500"=126.42cm^2=1.149w
3.945"=378.23cm^2=3.438w
4.230"=164.86cm^2=1.499w
4.600"=342.88cm^2=3.117w
4.850"=200.60cm^2=1.824w
4.900"=234.78cm^2=2.134w
5.375"=345.08cm^2=3.137w
5.880"=260.01cm^2=2.364w
7.280"=342.88cm^2=3.117w
8.460"=396.80cm^2=3.607w
10.00"=468.27cm^2=4.257w
10.08"=908.87cm^2=8.262w
I do understand that shape of the profiles do effect the passive cooling capabilities, but on paper this is what makes sense to me. If something is incorrect with how I'm viewing this please correct me, and I will change this post. If not and other people are having as hard of a time figuring out the proper size heatsinkusa for passive cooling, I hope this helps.
 
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bicit

Well-Known Member
There are too many pages for me to look though, did anyone ever just use water cooling and much smaller heat sinks with no fans, just water heat blocks? It should be even more effective than large heat-sinks with fans and potentially cheaper. Also a bonus is you can put your radiator and pump outside the room so you aren't blowing heat around the grow area.
observe and report built a water cooled cab. It works well and has interesting implications. It's not very practical for the average person though and certainly not cheaper. When you consider that you have to have a water pump(20-50watts) going constantly in addition to a high pressure fan(for the radiator ) it doesn't make a good case for the overall efficiency of the system.

http://rollitup.org/t/more-money-than-brains-a-water-cooled-cab-build.802108/
Thank you bicit.
From what I calculated from the charts on page 1 was:


Looks pretty similar to the numbers in my spreadsheet.
 
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nomofatum

Well-Known Member
observe and report built a water cooled cab. It works well and has interesting implications. It's not very practical for the average person though and certainly not cheaper. When you consider that you have to have a water pump(20-50watts) going constantly in addition to a high pressure fan(for the radiator ) it doesn't make a good case for the overall efficiency of the system.

http://rollitup.org/t/more-money-than-brains-a-water-cooled-cab-build.802108/

Looks pretty similar to the numbers in my spreadsheet.
Fan on radiator is only needed if the radiator is small, a motor cycle radiator would cool a lot of lights without a fan.

This 13w pump will work (add ac/dc converter to power), I used one for a 7ft tall hydro strawberry system outdoors.
http://www.aliexpress.com/item/12V-DC-Mini-Brushless-Magnetic-Self-priming-Hot-Water-Pump-65-degrees-C-ZC-A40/1596115565.html

I used it for solar 12v, but it will work inside with a ac/dc converter too or I'm sure there is a 110v version out there. I also tested and it can pump to heights over 15ft (just a trickle at that height.)
 

PurpleBuz

Well-Known Member
There are too many pages for me to look though, did anyone ever just use water cooling and much smaller heat sinks with no fans, just water heat blocks? It should be even more effective than large heat-sinks with fans and potentially cheaper. Also a bonus is you can put your radiator and pump outside the room so you aren't blowing heat around the grow area.

logistic nightmare. The grow space has to be well ventilated regardless of light source, so might as well use that to get rid of excess heat.
 

bicit

Well-Known Member
Fan on radiator is only needed if the radiator is small, a motor cycle radiator would cool a lot of lights without a fan.

This 13w pump will work (add ac/dc converter to power), I used one for a 7ft tall hydro strawberry system outdoors.
http://www.aliexpress.com/item/12V-DC-Mini-Brushless-Magnetic-Self-priming-Hot-Water-Pump-65-degrees-C-ZC-A40/1596115565.html

I used it for solar 12v, but it will work inside with a ac/dc converter too or I'm sure there is a 110v version out there.
Go for it, report the results. If you're running a sealed environment with zero air exchange, I could see water cooling being a practical option. However it's going to be an expensive venture by the time you get the water blocks, fittings, tubing, pump, radiator, clamps, and other necessities. Then there is always the safety concern of mixing water with high voltage electrical devices. PC water cooling is a niche market for that reason as well.

It's just hard to beat the price and simplicity of a fan and a hunk of aluminum(maybe even without the fan). You should go back and read a few pages on supra's testing. It's surprising how easily it is to hit the point of diminishing returns for cooling power.
 

nomofatum

Well-Known Member
Go for it, report the results. If you're running a sealed environment with zero air exchange, I could see water cooling being a practical option. However it's going to be an expensive venture by the time you get the water blocks, fittings, tubing, pump, radiator, clamps, and other necessities. Then there is always the safety concern of mixing water with high voltage electrical devices. PC water cooling is a niche market for that reason as well.

It's just hard to beat the price and simplicity of a fan and a hunk of aluminum(maybe even without the fan). You go back and read a few pages on supra's testing. It's surprising how quickly you hit the point of diminishing returns for cooling power.
I'm entertaining the idea for if I decide to run in summer this year. I wouldn't need much to setup a system. A copper coil water supply line for a fridge/drinking water, thermal epoxy, rubber hoses and adapters to connect the coil to pump, pump to radiator, radiator to coil. You would just have and in and out hose coming into your grow area. The copper coil would be thermal epoxied to the smaller heat sinks (or simple aluminum channel/angle.)

I will just find a $10 scrap radiator if I do this.
 

nomofatum

Well-Known Member
Aluminum is not a good idea to use. Brass and copper should get along fine.
Most car/motorcycle radiators are aluminum, so that will be pretty much a requirement.

I see that I should just use a corrosion inhibitor in my coolant to make sure the copper doesn't get corroded by the aluminum from a forum on PC water cooling.
 
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