Heatsinks for DIY LED lamps

Voidling

Voidling

Well-Known Member
@SupraSPL
Did I do the above numbers right?

How about these?

Extruded Aluminum Heatsink
Width: 1.813"
Fin Height: .95"
Base: .300"
C/W/3": approximately 4.5
Weight per Inch: .10

(1.813 x 2) + (0.300 x 2) + (0.95 x 2 x 6)
(3.626) + (0.6) + (11.4)
15.626 perimeter
15.626 x 6.4499618029
100.8 cm squared

100.8 / $0.66
151.5 cm/$
 
bizfactory

bizfactory

Well-Known Member
Is there any cheaper option for 8x CXB3950s mounted to a big heatsink other than heatsinkusa? One heatsink of the 10.08" profile with a 25" length is $165 before shipping!! That's absurd!

Is the shorter finned 12.00" profile any good? I'd be mounting a 140mm fan on it and COBs @ 700mA
 
Voidling

Voidling

Well-Known Member
Width is 12.000"
Fin Height is 1"
Base Height is .300"
Weight is approximately .60 lbs per inch
C/W/3": approximately .85

(12 x 2) + (0.3 x 2) + (31 x 2 x 1)
(24) + (0.6) + (62)
86.6 perimeter

86.6 x 6.45 = 558.57 cm2

Price $5
558.57 / 5 = 111.714 cm/$

Really wish I could get confirmation on my equation.

If I did it right it looks like the 10.08" has more surface area
 
AllDayToker

AllDayToker

Well-Known Member
bizfactory said:
Is there any cheaper option for 8x CXB3950s mounted to a big heatsink other than heatsinkusa? One heatsink of the 10.08" profile with a 25" length is $165 before shipping!! That's absurd!

Is the shorter finned 12.00" profile any good? I'd be mounting a 140mm fan on it and COBs @ 700mA
Click to expand...
Should see my passively cooled 10" x 62" heatsink for my 8x 3070s. Looks clean in the closest but fuck does that thing weigh a ton haha.
 
AllDayToker

AllDayToker

Well-Known Member
Voidling said:
Damn. Why go with one extremely long one instead of smaller ones? My plan is modules to adapt to different size grows as I move around
Click to expand...
Well two separate panels would of been more practical but I was making a light for a long and skinny grow area, so a long and skinny light fit.

The two lights would help a little bit more with spread, and would help with growing different strains that will get different heights.

But I grow under a screen, and my sativa dom. And indica dom. Plants are suppose to finish at,the same time, we will see. Plus I love the one piece look, besides the passive only cooling required.

You want to match lighting to sqft, and get the most out of odd and/or unusual spaces, this cob shit is where it's at.

I could easily run some small pc fans at a low wattage to cut away from all the heatsink, but now I have a large piece to work with.

I can add more lights and drivers and add fans as I please. I have a lot of play space with a passively cooled setup.
 
alesh

alesh

Well-Known Member
bizfactory said:
Is there any cheaper option for 8x CXB3950s mounted to a big heatsink other than heatsinkusa? One heatsink of the 10.08" profile with a 25" length is $165 before shipping!! That's absurd!

Is the shorter finned 12.00" profile any good? I'd be mounting a 140mm fan on it and COBs @ 700mA
Click to expand...
At least something is cheaper in Europe:) I'm getting heat sinks at about $7/kg incl. VAT and shipping.
 
qwerkus

qwerkus

Well-Known Member
alesh said:
I'm wondering if you'll be saying this once you peek inside the case of the driver...or after a year of use.
Yes, some small MW drivers are pretty expensive but ie HLG-185H-C or ELG-150-C series have the top quality parts, functions and protections with a competitive pricing.
Click to expand...
Acutally, they sent me a picture! I agree about HLG-185H-C, but I'd rather take many small drivers than one large. For the rest, nearly all electronics we are using is made in china, wether it's apple or a cheap led driver. You have to know what you do before ordering, and ask for the right docu. Before my last order, I asked to see the test charts; wasn't great, but not bad either.
 
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J

J-Icky

Well-Known Member
I just went ahead and ordered 6 of the alpine 64 gt rev 2 heatsink/fans. If what I read is true the flat base on the extrusion is 1.5", which means it is just bigger than the vero 18s I plan on using. So The thermal paste should cover the bottom of my cob easily and it should fit perfectly. Now I just have to figure out what power supply I can use to power the fans. I know I just hook all the wires together and then connect those to the dc side of the driver. But I honestly wish there was a controller I could use to control the fan speed, but the only ones I have found in a quick glance around the net are for 3 pin and these fans have 4 pin connectors. Are there adjustable voltage power supplies I could use to control fan speed, kinda like they have dimmable drivers for cc. I hope so cause it would be much easier to only worry about wiring the red and black wires off the fan and then being able to dim the power supply to control the fan speed.
 
Voidling

Voidling

Well-Known Member
I would not hook up the fans to an led drive if that's what you mean.

I'll see if I can find what I'm thinking of
 
littlejacob

littlejacob

Well-Known Member
Bonjour
If you want something cheap and good for 4 fans look at Meanwell APV-12-12...or just as me an universal 12V dimmable psu for less than 8 $
Have a great day ★
 
J

J-Icky

Well-Known Member
Sorry no I was talking about wiring the fans to a separate power source, not a cc led driver. But what I really want is to be able to wire the six fans in 2 sets of 3 and to be able to easily adjust the fan speed. So I would have 3 of the fans hooked up into a single power supply with dimming or whatever and the other 3 into a second power supply with dimming.
Also, the fans run at 12v but with 160mah, so for the 6 combined I'd need a 960mah 12v driver, or 2 480mah 12v drivers. I would prefer 2 just incase 1 of the power supplys fail I would still have at least 3 working fans moving air.

That fan controller looks awesome, just not sure I need that much power, 5 channels pushing 15 watts each. I would need less than 12 watts to power all 6 fans to max. I really like the fact that it would also give me the temp. I may have to do alot more research into that. But in reality I'd be happy with something that had 6 channels pushing a max of 2w each and had old fashion knobs to turn them up and down in speed, as long as it was at least half the price of the one you linked too.

Thanks for the replys, you've given me alot too look into and at the very least given me the start in the right direction to look into the more advanced stuff I'd like to get into and use.
 
SupraSPL

SupraSPL

Well-Known Member
Voidling said:
Width is 12.000"
Fin Height is 1"
Base Height is .300"
Weight is approximately .60 lbs per inch
C/W/3": approximately .85

(12 x 2) + (0.3 x 2) + (31 x 2 x 1)
(24) + (0.6) + (62)
86.6 perimeter

86.6 x 6.45 = 558.57 cm2

Price $5
558.57 / 5 = 111.714 cm/$

Really wish I could get confirmation on my equation.

If I did it right it looks like the 10.08" has more surface area
Click to expand...
Your equations are correct regarding the perimeter. There is one point of complexity for the wide profile sizes, a 1" length has ~10% of its surface area on the cut sides. So that makes it hard to offer a "surface area/inch" guide for people to use because at longer lengths it will have much less of its surface area on the cut edge. I havent figured out a solution for that yet except people would need access to the interactive spreadsheet or something similar. So a 1" length of the 12" profile has ~ 600cm² rather than 558cm². For longer lengths it would not matter much.

The 10.08" has an extra thick base, extra thick fins, wide fin spacing and very tall fins. The tall fins makes it passive cooling unfriendly and if it was active cooled it would pack too much light in a small area. I do use them for passive cooling (because I had a bunch on hand) but I more than doubled the surface area to make up for it. It is cheaper/surface area than the 12" profile. The 10" profile is much cheaper/surface area than the 12" profile.
 
K

kliend

Active Member
Hey ya'll,

Quick question. Are my LEDs running too hot? I ordered based off of Supra's chart here:

@ 56.3%
(4) CXB3590 3500K CD 36V @ 1.4A (49W ea) $190
(1) HLG-185H-C1400 $65
196 dissipation W -> 85.7W heat ->
passive cooled heatsink 10284cm² -> 5.88" X 38" heatsink $72 (could split in 2 to improve uniformity/spread)
110.3 PAR W covering 6ft² = 824 PPFD
passive cooled (great value point IMO, very efficient use of driver)


In fact, I even went overkill and used a 40 inch heatsink instead of 36. But I do have glass lenses on and I do have the driver screwed on top of the heatsink.

Ambient temp: around 75* F
Reading on back of heatsink: 130* F ? (This is a hard reading to get, the reflective surface of the aluminum was messing with my IR thermometer. I tested with a piece of black tape and the temp went up 20*)

I'm starting to wish I included a PC fan in the build. Are my LEDs running too hot? Should I be worried or am I overthinking about it?
 
SupraSPL

SupraSPL

Well-Known Member
130F/55C aluminum would feel very hot, almost too hot to touch. If it is that hot it will not harm the COBs in the short term, but much higher than we are aiming for. You can also try other types of thermometers to verify the temp, mercury or meat thermometer style. That said, the design is ultimately semi passive and benefits quite a bit from the circulation fan. Is there any air movement in the tent while you are getting these readings and is any of the circulation fan air hitting the heatsink? If the heatsink is installed close to the ceiling where it cannot effectively dissipate heat, active cooling will address that.

I have a 5.88"X12" so I will run some tests and see how hard I have to push it in a static air condition to get it up to 130F so we have another reference point.
 
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