LED temperatures

What kind of temps are you guys seeing with LED setup.

Mine gets pretty warm, just wondering whats "normal"

with a fan on full intensity, i saw 103.9*
 
that seems warm to me but I havent checked mine with an temp gun. I run 24 cree on a 4*23 heatsink with 1 fan and mine are cool to the touch
 
Based on the data sheets and research the cree XP-G LEDs will run for 19 years at 153 degrees. You could be a little warm but I would not be extremely concerned with losing life out of them.
 
@niteowl03 wrote:
Based on the data sheets and research the cree XP-G LEDs will run for 19 years at 153 degree. said:
Do realize that that would be inside of a controlled laboratory setting, with an ambient temp of 77*F. [smilie=wink.gif] That said.... 105*F is fine.

Cheers,
 
@bimmerzs wrote:
[I]@niteowl03 wrote:[/I][quote="Based on the data sheets and research the cree XP-G LEDs will run for 19 years at 153 degree. said:
Do realize that that would be inside of a controlled laboratory setting, with an ambient temp of 77*F. [smilie=wink.gif] That said.... 105*F is fine.

Cheers,"]

77degrees is pretty cool for any electrical fixture running this much juice through it.....ive never seen or heard of this particular stat.......where can I find this information? Thanks in advance.
 
I'm reluctant to believe that 77 degrees would be the right temp as many manufactured fixtures don't run this cool and they are extremely successful

Sent from my Inspire 4G using Tapatalk
 
77 degrees f is probably a reference to the junction temperature vs effeciency/output graph on crees data sheets. too hot to hold is too hot, or at least thats my motto.

Tapatalkput
 
Got my curiousity going, so I pulled out my temp gun. I run 3- 120w Evolution fixtures in an open top- suspended canopy. 20K-14K-20K configuration.
1st.) 20K Face = 101.9 Top @ fan 78.4
2nd) 14K Face = 96.9 Top @ fan 80.1
3rd) 20K Face = 105.1 Top @ fan 81.6

Tank 79.0
Ambient air 74.8

I'm sure dust build up will contribute to inefficiencies in heat dispersal.
 
In comparrison, I have a 150W HQI Coralife fixture with a burned up fan. Face of MH bulb glass 347 deg. !!! Top where fan should be exhusting.. 172.7 Deg. Light came on at 9am, so.. about 3 hrs run time. Water = 80.1 Air = 73.5

I really need to order that replacement fan!
 
@Pool Man wrote:
In comparrison said:
HOTT DAM!!!!! [smilie=thinking.gif] thats some warm stuff.

I actually, oddly enough have my fan over my LED's hooked up to my fan controler in my computer. Ill post pics later tonight, I need to run an ext wire from the controler for the temp probe so that I can program the controler to respond accordingly. very handy if you have the setup near a tank.
 
@JBsmurf wrote:
[I]@bimmerzs wrote:[/I][quote="[I]@niteowl03 wrote:[/I][quote="Based on the data sheets and research the cree XP-G LEDs will run for 19 years at 153 degree. said:
Do realize that that would be inside of a controlled laboratory setting, with an ambient temp of 77*F. [smilie=wink.gif] That said.... 105*F is fine.

Cheers,"]

77degrees is pretty cool for any electrical fixture running this much juice through it.....ive never seen or heard of this particular stat.......where can I find this information? Thanks in advance."]

Pretty much every led manufacture base their output spec's on the junction temp, we can go into an extremem amount of detail on this but it is much easier to reference the data sheets. The aquastyle uses the bridgelux led's but most led manufactures test under similar lab conditions and not real world condition's. The below graph is from a bridgelux datasheet and shows the led's are running at 350ma with a juction temp of 25*C/77*F. The actual light output is not important for this example but will show you that if you had these same led's running at 700ma then that junction temp would get pretty high and shorten the life and output characteristic's of the led. You can extrapolate this across every led out there including cree's, running the led's at higher current's/forward voltages equals more heat and shorter life. When you start cranking up the current to led's and then run into a cooling issue either with the led fixture etc or the room temp, then you can get into issues.

LED_Data.png
alt="">


Cheers,
 
@JBsmurf wrote:
[I]@bimmerzs wrote:[/I][quote="[I]@niteowl03 wrote:[/I][quote="Based on the data sheets and research the cree XP-G LEDs will run for 19 years at 153 degree. said:
Do realize that that would be inside of a controlled laboratory setting, with an ambient temp of 77*F. [smilie=wink.gif] That said.... 105*F is fine.

Cheers,"]

77degrees is pretty cool for any electrical fixture running this much juice through it.....ive never seen or heard of this particular stat.......where can I find this information? Thanks in advance."]

The info is in the data sheets, I can help you find it if you like. Here's from the Cree XP-G datasheet, now everybody know's most people run their cree's at 1000ma but looking at the datasheet, all you will see is info based on 350ma. The cheap fixtures with several loud running fan's are there to help overcome the lack of effective heat management. http://www.cree.com/products/pdf/xlampxp-g.pdf

Cree_data.png
alt="">

Cheers,
 
"bimmerzs' wrote:
The cheap fixtures with several loud running fan's are there to help overcome the lack of effective heat management. http://www.cree.com/products/pdf/xlampxp-g.pdf

Cree_data.png
alt="">

Cheers,


what cheap fans?
 
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