Heatsinks for DIY LED lamps

SupraSPL

SupraSPL

Well-Known Member
Finally got around to organizing this and I figured it might come in handy for those who are designing DIY lamps. These charts show the surface area and surface area/cost for each of the Heatsink USA profiles.
HeatsinkUSA.png

So in summary, the cheapest surface area is the 2.08" profile. It gives a lot of spread, maybe too much spread for our purposes. The 4.85" is also cheap and might be good for a vegging heatsink. Thin base plate though, not ideal for COBs.

The 4.6" serrated is a good value and it has a .23" baseplate thickness/riser height so it might be good for COB and gives a good spread between COBs. It has decent height to the fins, so uses active cooling efficiently (120mm fan should cover all fins). The 4.9" has a thick.3" base plate and still gives a good spread, should be very good for high powered COBs. Same with the 5.88" and it fits 140mm fans.
 
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SupraSPL

SupraSPL

Well-Known Member
One of the tried and true CPU coolers many DIYers are using:

100W CPU Coolers:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186070&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-CPU+Fans+&+Heatsinks-_-N82E16835186070&gclid=CL_Ds4Ogk8ICFSgQ7Aod8X8AJQ

I have some of these on order to test with very high dissipation Vero29:
150W CPU Coolers:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186093&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-CPU+Fans+&+Heatsinks-_-N82E16835186093&gclid=CO2fw46gk8ICFQ4Q7Aod6nAAJA
 
DonPetro

DonPetro

Well-Known Member
SupraSPL said:
One of the tried and true CPU coolers many DIYers are using:

100W CPU Coolers:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186070&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-CPU Fans & Heatsinks-_-N82E16835186070&gclid=CL_Ds4Ogk8ICFSgQ7Aod8X8AJQ

I have some of these on order to test with very high dissipation Vero29:
150W CPU Coolers:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186093&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-CPU Fans & Heatsinks-_-N82E16835186093&gclid=CO2fw46gk8ICFQ4Q7Aod6nAAJA
Click to expand...
Can you suggest a "plug and play" power supply for the AA11?
 
C

churchhaze

Well-Known Member
I have a few artic 11 setups and I don't like them as much as the heatsinkUSA sinks I have. It's a purely active design with thin fins and fin spacing with a dedicated 90mm fan for 1 cob.

1 Vero 18 at 700mA doesn't justify its own 90mm artic 11 fan. You'd have to make some sort of mod to slow it down. The less power the cob uses, the more the 90mm fan is a waste.

To get the best economic value out of the artic 11, you really have to load it with heat. A vero 29 or cxa3070 at 2.1A makes it easier to justify the fan, but then you run a bigger risk if the fan goes out. The sink will get blistering hot because the fins are so close together.

Also, the wires/connectors on the artic 11 are crap. You get what you pay for. The fan has no backwards protection diode, and will break when you run backwards voltage. I've had the connector rip off one with minimal stress. They're not the worst, but they also kinda suck.

Then yet another disadvantage to the artic 11 is it's mounting base. You can only put one cob on, and no stars along the perimeter.

Another advantage to larger, semi-passive heat sinks is making it safer to use 1 driver for multiple cobs in series. If the cobs in series are on the same heat sink, there is less risk of opening the circuit and creating a short risk. The wiring can be done much more snug since the cobs are all on the same sink.

I think it's better to use the heatsinkUSA sinks as they're wider and longer and less reliant on any individual fan working. Also, what else are you going to put between your heat sinks if not more heat sink mounting surface.

Use all the heatsinks!!
 
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Positivity

Positivity

Well-Known Member
One thing I love about the CPU cooler cooler approach is the weight savings. So much lighter...especially when it comes to shipping weight with the bigger heatsinks. I worked out the cost a little the other day and I can actually build them for about the same price using either. The CPU coolers ship for free.

I must say it was nice hauling out my heavy ass veg 2ft sink and putting in a light box..

But on the other hand..my 2ft - 10" profile Heatsink USA flower light does a helluva good job with 400w of cxas

Either way I guess..:razz:
 
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FrozenChozen

FrozenChozen

Well-Known Member
SupraSPL said:
Good question DP. Maybe with a PSU like this:
http://www.amazon.com/Coolerguys-100-240v-Molex-Power-Adapter/dp/B000MGG6SC/ref=pd_sim_e_4?ie=UTF8&refRID=1XS6ZPDFAG8ES4PTN872

and then with some fan power splitters you could put together a plug and play setup.

My strategy has been to cut the ends off the fan and the PSU and make my own connectors and splitters, but it is time consuming
View attachment 3300211 View attachment 3300212
Click to expand...
Your builds always look so clean! Who cares how time consuming it gets, you do a killer job!
 
bicit

bicit

Well-Known Member
So supra, using the equations you gave me in another thread. I estimated that a 32" piece of the 4.85 profile would be able to displace 200 watts of power if actively cooled. Obviously it's overly simplified since it does not take into account the performance of or the number of fans.

Would a single 120mm fan be inadequate to cool 200w? Or is the system as a whole inadequate?
 
SupraSPL

SupraSPL

Well-Known Member
Thanks FC, I am with you, I don't mind spending some time if there is a worthwhile benefit.

Bicit, yes I do believe a single 120mm fan would be sufficient and you could add a cover over the fins if necessary to get good airflow the entire length. You are correct there are other variables. Higher current fans will move move air at a given voltage. You can run it up to 15V if necessary.

Yes you could use a 32" piece but you could use as much as 40" if you want to reduce fan power and get a larger spread. The 4.85" does have a relatively thin base plate so if you are running COBs hard that might be an issue but I have not tested it.
 
DonPetro

DonPetro

Well-Known Member
SupraSPL said:
Finally got around to organizing this and I figured it might come in handy for those who are designing DIY lamps. These charts show the surface area and surface area/cost for each of the Heatsink USA profiles.
View attachment 3300177

So in summary, the cheapest surface area is the 2.08" profile. It gives a lot of spread, maybe too much spread for our purposes. The 4.85" is also cheap and might be good for a vegging heatsink. Thin base plate though, not ideal for COBs.

The 4.6" serrated is a good value and it has a .23" baseplate thickness/riser height so it might be good for COB and gives a good spread between COBs. It has decent height to the fins, so uses active cooling efficiently (120mm fan should cover all fins). The 4.9" has a thick.3" base plate and still gives a good spread, should be very good for high powered COBs. Same with the 5.88" and it fits 140mm fans.
Click to expand...
Regarding passive cooling...would the 3.5" profile at 36" be sufficient for 5 or 6 Vero 18's at 700ma?
 
SupraSPL

SupraSPL

Well-Known Member
DP, that gives you 4550cm² so at 110cm²/W, it would be good for about 40W of dissipation. So that would be (2) Vero 18s at 700mA.

In this case, if you added an 80mm or 92mm fan and ran it a 9V, (~2W) it should be sufficient for 115W, plenty for (4) Vero18s at 700mA.
 
SupraSPL

SupraSPL

Well-Known Member
epicfail said:
Loving the info Supra, I'm liking the new 4.9" profile and while surfing their site just now I found a pdf on the FAQ page with some good info in it also. In it I am seeing that some of theirs and your perimeter #'s don't match, check it out and see for yourself.

https://store-ddfcc.mybigcommerce.com/content/AvailableProfiles2014.pdf
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Thanks for the heads up EF, I double checked my work and it looks to be sound. The formula is really pretty simple: (profile width * 2) + (riser height *2) + (number of fins * fin height * 2) = perimeter. I confirmed the measurements with the tape measure and the numbers agree.

I would be curious to see what method they are using to get their figures?
 
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SupraSPL

SupraSPL

Well-Known Member
Just ran a test on the 3000K CXA3070 AB bin, mounted onto an Acrtic Apline 11 Plus heatsink with 92mm fan and Prolimatech PK3 thermal paste. The surface was flattened to 1000 grit. The idea of this test is check the theory that at 700mA, there would be virtually no decrease in light output from Ambient temp to fully warmed up, thermally stabilized. Ambient temp was 21C. I did the test with 3 different fan speeds, 5V, 9V and 12V.

At 700mA (25W)
With 5V fan there was a decrease of .9% and a Tj increase of 7C (based on the Vf change).
With 9V fan there was a decrease of .6% and a Tj increase of 6C
With 12V fan there was a decrease of .44% and a Tj increase of 6C

I also did the test at 2.2A (87W) but it was a Z4 bin and mounted onto a different CPU heatsink with a copper pad that was manufactured perfectly flat. The results were interesting though:
At 5V there was a decrease of 3% and a Tj increase of 22C
At 12V there was a decrease of 2% and a Tj increase of 18.5C.

An finally, tested a Vero18 3000k 97CRi at 2.2A (69W), mounted on a CPU heatsink with copper pad, manufactured flat. This Vero is running at very high current and it is a very low efficiency COB (18%) so I was expecting much worse performance than this, a testament to the excellent thermal package of the Vero.
no fan! - 22% decrease, Tj increase of 55C
5V fan - 12.5% decrease, Tj increase of 29.3C
12V fan - 5.8% decrease, Tj increase of 11C
 
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C

churchhaze

Well-Known Member
The losses from being 97CRI comes from the yellow phosphor coating I thought. The blue dies are no less efficient, right?

SupraSPL said:
An finally, test on a Vero18 3000k 97CRi at 2.2A, mounted on a CPU heatsink with copper pad. This Vero is running at very high current and it is a very low efficiency COB so I was expecting much worse performance than this, a testament to the excellent thermal package.
no fan! - 22% decrease, Tj increase of 55C
5V fan - 12.5% decrease, Tj increase of 29.3C
12V fan - 5.8% decrease, Tj increase of 11C
Click to expand...
 
SupraSPL

SupraSPL

Well-Known Member
That is correct CH, rather than boost up the output of the light blue and deep red, they simply decrease the output of everything else to make a flatter curve. And the 97CRI really takes that idea to the max.

I use the 97 CRI for indoor photography so I don't need a ton of light and it is only running for relatively short periods of time, so for this purpose the Vero18 97 CRi is great at what it does. I could probably crank it higher than 2.2A if I needed more light for some reason. Normally I keep it on a 500mA-1800mA dimmable driver.
 
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