Heatsinks for DIY LED lamps
- Thread starter SupraSPL
- Start date
littlejacob
Well-Known Member
Bonjour
What about raijintek rhea X 3= 20 $ in newegg if you want cpu cooler?
Have a great day ★
CanadianONE
Well-Known Member
littlejacob
Well-Known Member
Bonjour
Good question...I don't know, I never used those sorry.
I took a h.s + fans.
See you
Good question...I don't know, I never used those sorry.
I took a h.s + fans.
See you
dandyrandy
Well-Known Member
I think I've just about bought them out. Sorry.
littlejacob
Well-Known Member
QUOTE="Oldsoul7, post: 11870949, member: 568682"]It's all good dandy. What size heatsink are you running and for how many watts LJ?[/QUOTE]
Bonjour
I have 4 3590 on a hlg 185 1400 so normally about 200w on a (sorry metric system...) 1000X165X35mm h.s cut in 4 pieces for a better spreading...and so bright...
Have a great day ★
Bonjour
I have 4 3590 on a hlg 185 1400 so normally about 200w on a (sorry metric system...) 1000X165X35mm h.s cut in 4 pieces for a better spreading...and so bright...
Have a great day ★
silvrsurfer77
Well-Known Member
I apologize if this was covered, but I did read thru alot of this and did not find what Im looking for. So heres my questions...
How do you calculate heat watts from dissipation watts?
Also is there a formula for how much surface area per watt is required...is that heat watts or dissipation watts?
Then how do you calculate how much with active cooling and how much active cooling (1 fan or 2,3...)?
Basically Im very new and Im trying to understand what Im building. I got all this from SurpraSPL in another post and have started building it...
From SupraSPL
"@ 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)
or
active cooled heatsink 3428cm² min -> 3.5"X36" heatsink (for spread) $45 +80mm fan +psu $10
(4) lenses $16
110.3 PAR W covering 6ft² = 824 PPFD
$311 = $3.07/PAR W passive cooled (great value point IMO, very efficient use of driver)
$326 = 2.96/PAR W active cooled?
( I chose to do 3 of these on 5.88" x 36" heatsinks...for 4x4 tent....dont think I need fans)
Since I started with close to zero knowledge on electricity and LEDs, I decided to outline notes and formulas of what I learned so far and I want to make "all in one" kinda guide on everything from understanding ohms law, the COB color, bin, voltage, driver, heatsinks, cooling, wiring, efficiency, PAR W, etc. I really dont want to be the one to do as Im sure one of the pros here could write it up in 5 mins, but since Ive been digging on here for weeks Ive noticed its very time consuming and hard to find what you need from each thread, I figured maybe ill save some future DIYers some time as well as keep people interested......Im finding its not nearly as hard or complicated as I thought....just hard to find Math formulas or a comprehensive newb guide.......If anyone wants to help with this guide, my inbox is open
How do you calculate heat watts from dissipation watts?
Also is there a formula for how much surface area per watt is required...is that heat watts or dissipation watts?
Then how do you calculate how much with active cooling and how much active cooling (1 fan or 2,3...)?
Basically Im very new and Im trying to understand what Im building. I got all this from SurpraSPL in another post and have started building it...
From SupraSPL
"@ 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)
or
active cooled heatsink 3428cm² min -> 3.5"X36" heatsink (for spread) $45 +80mm fan +psu $10
(4) lenses $16
110.3 PAR W covering 6ft² = 824 PPFD
$311 = $3.07/PAR W passive cooled (great value point IMO, very efficient use of driver)
$326 = 2.96/PAR W active cooled?
( I chose to do 3 of these on 5.88" x 36" heatsinks...for 4x4 tent....dont think I need fans)
Since I started with close to zero knowledge on electricity and LEDs, I decided to outline notes and formulas of what I learned so far and I want to make "all in one" kinda guide on everything from understanding ohms law, the COB color, bin, voltage, driver, heatsinks, cooling, wiring, efficiency, PAR W, etc. I really dont want to be the one to do as Im sure one of the pros here could write it up in 5 mins, but since Ive been digging on here for weeks Ive noticed its very time consuming and hard to find what you need from each thread, I figured maybe ill save some future DIYers some time as well as keep people interested......Im finding its not nearly as hard or complicated as I thought....just hard to find Math formulas or a comprehensive newb guide.......If anyone wants to help with this guide, my inbox is open
AllDayToker
Well-Known Member
Having troubles finding the right size heatsink for my setup.
I am trying for passive air cooled so no extra fans are needed.
I'll be running 8 CXB3070s, running 4 on a single HLG 18h c1400b 1.4a.
Trying to cover my 6' by 2' flowering canopy.
I am trying for passive air cooled so no extra fans are needed.
I'll be running 8 CXB3070s, running 4 on a single HLG 18h c1400b 1.4a.
Trying to cover my 6' by 2' flowering canopy.
SupraSPL
Well-Known Member
One way to find heat watts -> multiply dissipation W * efficiency. That gives you PAR W. Subtract PAR W from dissipation W and you have heat W.
I have been recommending 40cm²/W for active cooling and 120cm²/W for passive cooling (using passive cooling friendly heatsink profiles). That recommendation is referring to heat Watts
If you are active cooling on CPU cooler, 5V seems to be the best overall efficiency, even when driving COBs above 50W. On a long heatsink you might want more power to the fans, 9V does the job very well but it depends on the current of the fan motor used. (Use 80mm fan for 3.5" heatsink, 120mm fan for 4.9" and 140mm for 5.88"). I have never taken the time to approximate CFM because I figured it varies depending on the pressure the fan is seeing and the accuracy of manufacturer specs. Instead I have been examining the actual temp droop from the COBs and comparing that to the power used in the fans.
In this test .5W of fan power was enough to cool a 100W COB. (92mm fan on the Rosewill RCX-Z1 CPU cooler, running at 5V)
SupraSPL
Well-Known Member
So you have about 210 heat Watts and ~720 PPFD. Great setup, in order to get as uniform coverage as possible you could stagger the COBs a bit. You could use one giant heatsink 8.46"X62" or you could break it up into 2 sinks 10"X28" each.
AllDayToker
Well-Known Member
Great to hear.
Yeah I planed on staggering them for the best coverage possible.
What would you think would be a better choice? Splitting them up or doing a large one?
I would like the option of upgrading, adding more cobs/drivers, and adding fans to it to help with heat when I do upgrade. Think a single one would be better if I want to do that later on?
Just figured I'd be adding cobs as I go to tweak the system.
littlejacob
Well-Known Member
Bonjour
I went the 1 cob per heatsink way...since cobs are multiple sources of light why put them all on the same hs? I am adept of spreading. I believe that each cob have to be at the center of the area it cover, in order to use it at full capacity and have it own h.s for flexibility!
I spaced them at 15/16 inch.between cobs.
Have a great day ★
I went the 1 cob per heatsink way...since cobs are multiple sources of light why put them all on the same hs? I am adept of spreading. I believe that each cob have to be at the center of the area it cover, in order to use it at full capacity and have it own h.s for flexibility!
I spaced them at 15/16 inch.between cobs.
Have a great day ★
CanadianONE
Well-Known Member
Not testing your numbers @SupraSPL more like testing my calculations lol But could he not use 10" x 26"? I know its only two inches and better to have more then not enough. Just want to make sure I have been doing calculations correct more then anything. On another note I had came up with 677 PPFD can you clarify your calculations so I can see where I might have went wrong?
CanadianONE
Well-Known Member
Here are my calculations for you to see @SupraSPL I would like to figure out where I went wrong so I can make proper calculations in the future lol
SupraSPL
Well-Known Member
its saul good man, a great thing to double check our maths, I am notorious for "careless mistakes" always rushing through too much math since 1st grade LOL. Anyway, looks like your surface area is very close to my figure. What is the formula in Box F4 of your first sheet?
Regarding PPFD, looks like you used AB bin and I used AD. Here is where my math came from, assuming CXB3070 3000K AD bin at 1.4A.
50W X 8 = 400 dissipation W
400 * .48 efficiency = 192 PAR W and 208W of heat
192 * .9 (lens/reflecter/scatter losses) = 172.8 PAR W / 12ft² = 14.4 PAR W/ft²
14.4 * 4.66 * 10.7 = 718 PPFD
208W of heat * 120cm²/heat W = 24960 cm² of heatsink surface area for passive cooling
He has 72" of width so if we take 6" of each end we get about 60" that should be covered by the heatsink, depending how close to the edges the COBs are mounted. The 8.46" X 62" is 24634cm², a bit less than the recommendation but should work well.
A pair of 10"X28" is 26,261 cm², slightly more than the recommendation but offers good spread and good opportunity for staggering. He could definitely tweak it a bit and with 26" pieces, The 10" is a bit cheaper/cm² and if it were me I would prefer the system in 2 pieces for adjustability and it works well as far as wiring, one driver and 4 COBs per heatsink. Then again if you have an even canopy, one heatsink might be a great way to go.
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CanadianONE
Well-Known Member
F4 is G2/110 for total surface area / 110cm2/heat watt
CanadianONE
Well-Known Member
I see that now and will update my spreadsheet thank you.