# Questions on Custom LED light for 125g



## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Hi, I'm about to order some LED's, drivers and power supply and would like comments if I have everything correct.
> 
> The tank is 72" long, 18" wide and 22" deep - 2-4" substrate. Full canopy on tank so light should go down not out. I want to keep the build as simple as possible and would like the look t5ho 6500k bulbs produce.
> 
> ...


LED voltage adds in series.. LED amps add in parallel..
LED's require a threshold voltage to work.. You cannot under volt them (much).. You can underamp them w/ output loss..

Keeping that in mind and this:


> Vero18
> 1050mA, 29.5V, 31W


A 36v power supply will be able to run one in series.. Multiple in parallel up to the amp output of the ps..
BUT you need to add drivers to make them constant current.. 1 LDD-h 1000mA per 18.. You can use bigger drivers (higher amps = more output= more heat) but you cannot use much less voltage (well 29 plus 3v driver loss 31V)

There are other ways to crunch the numbers..


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## robsworld78 (Aug 14, 2014)

Thanks, do you think these would be better LED's. I've been going through LED's for hours now, these look promising to me. $10 a piece. If I got 12 of these instead do you think that would work? I would make 2 rows of 6.

Since these are 6500k wouldn't they be the same as T5HO's and give the plants everything they need?

Manufacturer:	Cree, Inc.	
Product Category:	High Power LEDs - White	
RoHS:	RoHS Compliant Details	
Illumination Color:	Cool White	
Color Temperature:	6500 K	
Color Rendering Index - CRI:	80	
Viewing Angle:	115 deg	
Forward Current:	700 mA	
Forward Voltage:	18 V	
Mounting Style:	SMD/SMT	
Series:	CXA1310	
Packaging:	Tray	
Brand:	Cree, Inc.	
Height:	1.55 mm	
Length:	13.35 mm	
Luminous Flux/Radiant Flux:	1200 lm	
Maximum Operating Temperature:	+ 85 C	
Minimum Operating Temperature:	- 40 C	
Factory Pack Quantity:	100	
Width:	13.35 mm


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## gus6464 (Dec 19, 2011)

You can run 2 LDD in parallel to an LDD-1000H so that it cuts your LDDs in half. I highly doubt you will need to run them higher than 500ma anyway as they are potent. If you do this at the minimum you would need a 36V 4.2A power supply but you can get 48V 7.2A power supplies on the bay for ~$30.

Bump:


robsworld78 said:


> Thanks, do you think these would be better LED's. I've been going through LED's for hours now, these look promising to me. $10 a piece. If I got 12 of these instead do you think that would work? I would make 2 rows of 6.
> 
> Since these are 6500k wouldn't they be the same as T5HO's?
> 
> ...


Those look like XM-L. Price to performance ratio is considerably greater with Vero.


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## robsworld78 (Aug 14, 2014)

I was thinking these LED's would be better because of the 6500k? Isn't that better than 5600k and 2700k? Here's a link.

http://ca.mouser.com/ProductDetail/Cree-Inc/CXA1310-0000-000F0HK20E1/?qs=sGAEpiMZZMu4Prknbu83y1zhPTc0SxQxBoRT4NaCePkb7U5c8APy8g%3d%3d


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Since these are 6500k wouldn't they be the same as T5HO's?


no, even different T5HO 6500k's are different from each other.. There are thousands of ways to equal 6500K..

that said,most 6500k LED's are fairly similar, but also different.. 

White LED COLOR temp differences (not comparing 6500k's)










Plant action spectrum:








simplist approach is a mix of 2 whites.. w/ higher weighting for the "cooler" one


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## robsworld78 (Aug 14, 2014)

gus6464 said:


> Those look like XM-L. Price to performance ratio is considerably greater with Vero.


I agree, only 1200lm compared to 3000+ but like you said the Vero's are overkill. Wouldn't it just cost more upfront with the Cree's but operating should cost the same?

Bump: I was also thinking these because they will be close to the surface of the tank and having 6 in a row instead of 4 should give it an even light.


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## gus6464 (Dec 19, 2011)

robsworld78 said:


> I agree, only 1200lm compared to 3000+ but like you said the Vero's are overkill. Wouldn't it just cost more upfront with the Cree's but operating should cost the same?


Yes but why spend more for the same? Also it's not really the same as the spectrum of that 6500K Cree is not the same as the spectrum of a 97CRI and 90CRI Vero.

A single Vero 18 can cover an 18sq. inch area with ease at 24" high with no reflectors. 4x clusters of Vero would have no problem on your 72" tank.


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## robsworld78 (Aug 14, 2014)

I'm actually saving money, the veros are $128 the Crees would be $120, plus I need 2 less drivers.

I guess I'm confused on the kelvins. My current T5HO came with a 6500k and 10000k bulb and says on package ideal for freshwater plants. I didn't like the color it produced so went with 2 - 6500k bulbs and like it. So it looks like the higher kelvin is better. The Veros are 5600 and 2700k opposite from what these T5HO's are sold? Confused?

Bump: Those charts help, thanks! So technically shouldn't these T5 fixtures come with a 2700k and 5000k?

Bump: How about 1 - Vero13 2700k, 1 - Vero13 5000k (cheaper, don't need the vero18), 1 - Cree 6700k? Each on there own channel so I can mix each color? Or is it pointless to add the 6700k? I'm just worried about what I see, lol.


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## gus6464 (Dec 19, 2011)

Color temp is strictly preferential. Some people prefer a warmer color and some a cooler temp. You can buy T5HO bulbs in all colors to suit your desired look. I run a tank with quad t5HO and I have 1 red bulb, 1 purple bulb, and 2 6400K bulbs. It's all about preference. Now by going with those Vero you will not be able to get a 6500K look but more like 5000K. It's up to you to decide what color you want. If you want a cooler color then the Vero 5600K is not the way to go.

Also you need to decide what kinds of plants you want to grow. Are you doing Co2? A 6500K bulb is not very good at growing red plants unless you are blasting it with PAR. A 97CRI Vero is a lot better at growing reds because it has a ton of red spectrum on it. But again it's all a balancing act. You first need to decide what you want out of your tank and then go from there.


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## robsworld78 (Aug 14, 2014)

Yeah that 97 is a nice number, it seems the smaller the LED the less accurate it is. 

My plants are low - medium light and doing good under 2 - 6500k ho bulbs and that is the color I want, that's my 50g tank. I plan to put a controller on it so I can dim each type of bulb individually and that will probably solve color issues. I did want to add a few red plants in time so that's good to know. 

My other concern is having an even spread. The LED's will only be about 4" above the tank so I'm thinking more spread out evenly is better. That's why I started looking at the lower powered LED's. If I went with 50 3w LED's that gets expensive and might not penetrate deep. One day I might get a deep tank.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Bump: Those charts help, thanks! So technically shouldn't these T5 fixtures come with a 2700k and 5000k?


Technically for the plants .. probably.. Probem was stated above.. you can "mix" all sorts of colors to "average" 6500k.. and that is what that number means.. an AVERAGE color... The correct term is CCT (correlated color temperature) since flour and LED's are not "black body" light sources w/ a "true" K...


> The correlated color temperature (CCT) designation for a light source gives a good indication of the lamp's general appearance, but does not give information on its specific spectral power distribution. Therefore, two lamps may appear to be the same color, but their effects on object colors can be quite different.


http://www.lrc.rpi.edu/education/learning/terminology/cct.asp



> Another weakness of CCT is illustrated in Figure 8 by points A and B, representing two light sources with the same CCT (3000 K). Although lights A and B have exactly the same CCT they have very different chromaticities and will look very different to the eye. The light emitted by source A will look greenish-white, while the light emitted by source B will look purplish-white.


http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightsources/whatisCCT.asp


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Yeah that 97 is a nice number, it seems the smaller the LED the less accurate it is.


nope...

http://www.yujiintl.com/high-cri-led-lighting










"Tiny" 5630's.. 5.6 X 3 mm...
http://store.yujiintl.com/collections/frontpage/products/5630-high-cri-95-led


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## robsworld78 (Aug 14, 2014)

Sh*t's complicated thats for sure. I think I've made my decision on LED's, they'll be Cree CXA1304 Series with Mean Well drivers, $186 for this which sounds good to me. I should be able to stay under $500 for everything.

http://ca.mouser.com/ProductDetail/Cree-Inc/CXA1304-0000-000C0Y840E8/?qs=sGAEpiMZZMu4Prknbu83yy5jvTecRalIGMcJPHoHGWQ%3d

http://ca.mouser.com/ProductDetail/Cree-Inc/CXA1304-0000-000C0HC265F/?qs=sGAEpiMZZMu4Prknbu83y9VUK3Vb4TG%252bj0TBjCVLBYTZ04CnaR0rSA%3d%3d

I choose these because of price and I can have more balancing things out better. 

I'm going with 2700k and 6500k, the 6500k seems to cover basically what the 5000k covers in spectrum and gives me the color I would like to see.

This is based on the Luxeon 3535









Here's how I plan to lay them out. They are 7.5" apart expect where there are 2 colors I will put them next to each to mix better.









This would give me up to 15,000 lumens running them at 700ma, the max for them is 1amp. Do you think I have enough 2700k in there? Better than what I currently use I suppose.

I'm going to use the Mean Well LDD-700HW driver.
http://ca.mouser.com/Search/ProductDetail.aspx?R=LDD-700HWvirtualkey63430000virtualkey709-LDD-700HW

This is where I need help.

I believe I can run 4 LED's on 1 driver so I'll need 7 drivers?

How do I do the math to calculate what size power supply I need? I couldn't find anything on google.


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## jeffkrol (Jun 5, 2013)

I assume you are using the 9V(f) ones..
voltage adds in series..

+(1)- _____ +(2)- ______ +(3)-_________+(4)-______ =36V + 3 (driver "loss") = 39V PS
so go w/ 48V PS

So one driver per/4 LED's = 700mA 

Add 2 more 6500k (not "really" necessary but makes the design all balanced) and you need *7* Drivers..and a 48V ps w/ AT least a 5A/176W rating..

err.. after looking at the data sheet your V @700mA is like 10.1V
soooo
10.1 X 4= 40.4 + 3 = 43.4 so definitely a 48V PS.. 
10.1 X .7 = 7.07 x 18 = 127.2W.. and using a 10% safety limit = 140W


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## robsworld78 (Aug 14, 2014)

Yeah the forward voltage is 9v up to 10.5v so that could put me up to 45v.

Still confused, does that mean I need a 48v power supply for each driver?

How does this one look?

http://ca.mouser.com/Search/ProductDetail.aspx?qs=wWxCkh6mprxAfMA9pUwKHw%3d%3d


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Still confused, does that mean I need a 48v power supply for each driver?
> 
> http://ca.mouser.com/Search/ProductDetail.aspx?qs=wWxCkh6mprxAfMA9pUwKHw==


No, the drivers can be all parallel-d off the same power supply..
Ignore everything but the PS to driver wires (for now).. and the fact it's 220V..









Yes, that power supply is fine..


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## robsworld78 (Aug 14, 2014)

Great, thanks for your help, now I can order tonight and if all goes as planned have everything on Friday, fingers crossed.

So no question this should grow easy to medium plants? lol


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Great, thanks for your help, now I can order tonight and if all goes as planned have everything on Friday, fingers crossed.
> 
> So no question this should grow easy to medium plants? lol


don't forget the thermal paste or epoxy.. 
Are you going to glue or drill and tap???
and yes that should be a good medium light..


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## robsworld78 (Aug 14, 2014)

Yeah I was going to use thermal paste, that's better correct?

I guess if I use thermal paste I have to drill and tap, correct?

What do you recommend?

You didn't answer this, lol "So no question this should grow easy to medium plants?"

Come on give me a guarantee.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Yeah I was going to use thermal paste, that's better correct?
> 
> I guess if I use thermal paste I have to drill and tap, correct?
> 
> ...


I'm a masochist I drill and tap and use cheap paste (paste won't hold by itself well) The 2 part epoxy is too expensive for my taste and I like to swap diodes as well..There is a "heatsink plaster" yep that is the name.. that is like a thermal silicone. A cross between the epoxy and paste sort of..
As to a guarantee.. you missed my last line above..

Oh for $50 more you can control 4 channels for dimming.. Yes one PWM output can dim more than one meanwell..
http://shop.stevesleds.com/Typhon-Typhoon-LED-Controller-Typhon.htm


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## robsworld78 (Aug 14, 2014)

It's official, just ordered everything.

I checked with mouser they want $95 for a tube of adhesive, crazy... I'm just going to get the paste locally and drill and tap. Like you say this way they can be easily moved.

Bump:


jeffkrol said:


> Oh for $50 more you can control 4 channels for dimming.. Yes one PWM output can dim more than one meanwell..
> http://shop.stevesleds.com/Typhon-Typhoon-LED-Controller-Typhon.htm


Funny you mention that, I emailed them a while ago to ask if a channel could support more than one meanwell. The description only says it supports more than one for Steve's drivers.

He replied with this. "Do you mean run the outputs of multiple drivers in parallel? "

I replied but haven't heard back. 

So it will be ok? Hope you're around on the weekend.


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## robsworld78 (Aug 14, 2014)

What gauge wire do you recommend for the led's, solid core or stranded? I figure 22g solid.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> It's official, just ordered everything.
> 
> I checked with mouser they want $95 for a tube of adhesive, crazy... I'm just going to get the paste locally and drill and tap. Like you say this way they can be easily moved.
> 
> ...


As far as I remember.. the Typhon is based on the Arduino which has a max out of 30mA. I "believe" (can't verify at this point, it's buried over at Reef Central or Nano) but the Meanwell PWM circuit only draws like


> The _LDD_-_H PWM_ input requires a positive voltage of up to 6V DC, with a _current_ source providing 0.1mA


.. 2 per pin is considered quite safe..

Bump:


robsworld78 said:


> What gauge wire do you recommend for the led's, solid core or stranded? I figure 22g solid.


CREE recommendations are in the designer notes pdf..I believe the link is in the spec sheet.

For short runs (betwen LEDs) most use CAT6 pieces (the 23ga stuff) or better. Some Cat 5 (24g)..
I prefer heavier wire, where ever I can get it. 20ga or thicker.
As to stranded or solid I prefer solid so as to not have "stringies" to worry about. Many like the flex of strands. Personal choice really.
Stiffer and a bit hard to work w/ but for smaller diode count boards it's fine. Honestly I use more 18ga solid since that it what I use for the power cord (power supply to drivers to LED's). Bit stiff and overkill to be honest for short runs (3-4ft) but easy enough to get 8 conductor "thermostat wire" at Lowes. The only catch is it easily gets stressed and pop off the solder pads. 

The current to the LEDs is under 1A.. 

14ga from ps to wall..

ONE last thing for now.. IF you get a controller the only "tricky" thing is to remember to tie the PWM negative to the ps DC neg (not AC neg) or it won't dim at all...and usually all PWM grounds (neg) are tied together so only one wire is needed...I've forgotten this more times than I care to admit..Oh and wiring the LDD's "backwards" lets out the magic smoke... 

Again.. (more for my own verification..  )


> Yes. Connect the Typhon pwm negative to the LDD incoming negative (black wire). The alternative is to connect the negative from the Typhon power supply to the negative on the LDD power supply (the outputs that is, not the AC input to the power supply). The point behind this is to create a common ground reference. If you don't do this, the drivers will not work correctly.


http://www.nano-reef.com/topic/336421-ldd-driver-question/

Addendum CREE designer notes recommend 21ga wire for the 9v model.. smaller for others..20ga is a fair compromise..


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## robsworld78 (Aug 14, 2014)

Thanks!


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## jedimasterben (Aug 21, 2011)

LDD-H pull 53 microamps at 0% duty cycle on their PWM circuit, meaning that if each Typhon PWM pin supplies 30mA, then you can dim up to *535x *per pin.


In addition, it takes less than a second to pop an epoxied LED off of a heatsink using a flat screwdriver or a chisel.


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## robsworld78 (Aug 14, 2014)

Well LED's still haven't even shipped yet, suppose to go out today so Monday or Tuesday now. 

I did get the heatsink today. Went with 1" x 2" x 1/8" thick aluminum rectangular tube.

I bought this manual controller today, will it work? Guy I bought it off didn't really know but only $10. Can I hook up more than one driver to a single color on this thing? It's 3amps per color. It does use PWM dimming. It also says "three CMOS drain-open output".


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## jedimasterben (Aug 21, 2011)

For LDD drivers, no. You need a 5v PWM controller (typically Arduino-based). You can also convert a 0-10v signal to 5v PWM through a small converter board. O2Surplus sells those. Just add a 10v input and a potentiometer and you can have manual control.


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## robsworld78 (Aug 14, 2014)

damm! lol

Can I convert a 12v single to 5v PWM? I'm hoping to get the things I need for manual dimming locally, I'll get a nice controller another day.

I have an Arduino board, can I use that in any way?


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## jedimasterben (Aug 21, 2011)

Arduino is natively 5v PWM. Just hook it up and program it.


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## robsworld78 (Aug 14, 2014)

jedimasterben said:


> Just hook it up and program it.


oh yeah you make it sound so easy. I need knobs to control the dimming, can I hook it up to the controller I have?


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## jedimasterben (Aug 21, 2011)

You'd have to finish out the controller to have it fully functional, but I'm honestly not sure what all that entails. Someone like O2Surplus is much more qualified than I am in that regard. That being said, a Typhon is $50 and a Storm is $65, and has all the work done for you.


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## robsworld78 (Aug 14, 2014)

Those are excellent prices for the controllers and I have no problem spending the money but I don't want to wait for it. I plan to assemble this Monday or Tuesday and need something to control the brightness at that time. I'm sure I can't run it full.

Is there a program for the ardunio that I can just load? Maybe a program I can change the brightness value and reload till I get what I want?


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## jedimasterben (Aug 21, 2011)

Without an active PWM signal, LDD drivers 'float high', aka sit at 100%, so you can use them on a timer until you get a PWM signal going.

The good thing with a planted tank is that you aren't going to have an algae farm overnight if you're just waiting on a controller to arrive.


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## robsworld78 (Aug 14, 2014)

yeah but I was thinking 100% is to bright, lol. You settled it for me, I'll just hook up at 100% and wait it out, I won't have plants or fish in there for a week or 2 anyways.

I never saw the storm when looking at controllers, it looks better than the typhon. What do you think is better? I like the 6 channels. Do you know how many LDD drivers can go on one channel?


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## jedimasterben (Aug 21, 2011)

Oh hell, if the tank is empty, running it full on won't do anything but make you see spots if you look at them 

The Storm is a better controller from the getgo than the Typhon (though the Typhon can be reprogrammed to have some of the features of the Storm, but not all). 

The Storm gives ~40mA per PWM pin (six total), the Storm X gives ~10mA per pin (16 total). At 100% duty cycle, the LDD pulls 7.7µA on its dimming circuit. At 0% duty cycle, the LDD pulls 53µA on its dimming circuit. For the Storm, you can run up to 754x per pin for a total of 4,524x across the controller. For the Storm X, you can run up to 188x per pin for a total of 3,008x across the controller.


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## robsworld78 (Aug 14, 2014)

jedimasterben said:


> Oh hell, if the tank is empty, running it full on won't do anything but make you see spots if you look at them


I just had laser eye surgery and don't want to go blind again. 

I'm reading the manual for the storm and it looks quite a bit better than the typhon, I'm sure I'll order it up. I liked the typhon because I could set the channels on their own schedule and intensity but looks like the storm can do that and a lot more. I'm really glad you mentioned it, I was about to order the typhon but feel bad now because I was emailing Steve's and said I was ordering.

I don't think I'll ever need to hook up 4,524 drivers  let alone 188. I think I'm going stormx I like the diming display. 

Do you know where I can get the DS18B20 temperature probe? He mentions it but doesn't sell it.


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## jedimasterben (Aug 21, 2011)

LOL! When you go to fire it up, you should still have those REALLY dark sunglasses cover things they gave you, right? Put those on! B)

And yeah, the Typhon is good, but the Storm is better. I've been pimping stuff from Steve's for a couple of years now, and they're really awesome, but when better hardware is available, it doesn't make much sense to go with something else when the cost is similar.

I'm not sure about the probe. I think they're available direct from Coralux? If not, I'm sure you could find one on amazon or Ebay


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## robsworld78 (Aug 14, 2014)

Broke those designer glasses in bed, lol.

They should be giving you commissions, I'm sure you get them lots of sales.

Yeah 16ch that's crazy, you should be able to achieve any look with that. 

Last question for today and I think I know answer but want to verify before I order.

Plan to date is to have 7 drivers that means I can only use 7 channels right?

I need 16 drivers to use all channels right?


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## jedimasterben (Aug 21, 2011)

Yes, one driver can only have one PWM input. Luckily, though, LDD are DIRT cheap compared to everything else, so it's not much to get more and make more channels!

You can separate your tank into sections and dim left to right for sunrise/sunset.


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## robsworld78 (Aug 14, 2014)

Yeah cheap is good, that's why I asked cause I'm gonna get more with the stormx. Don't think I'll run 16 but maybe 10. Later I plan to add moonlights so need to save some for those.

Soon my shrimp will be dancing about.


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## robsworld78 (Aug 14, 2014)

I picked up some 1" x 2" x 1/8" thick aluminum tubing and was going to make my frame however I didn't realize but the glass lids get in the way of 2 strips of LED's. Now I'm thinking I only have room for 1 - 66" heatsink. 

Do you think all the LED's could go on this without overheating? Is there a rule to follow for heatsink to LED wattage?


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## jedimasterben (Aug 21, 2011)

What kind of heatsink? Is it the tube heatsink that you talked about earlier?


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## robsworld78 (Aug 14, 2014)

Yeah, its tube, here's a pic.


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## jedimasterben (Aug 21, 2011)

I wouldn't run that many LEDs on just one. In addition, you'll really need a pressilurized fan to push through it, I've never seen one that has a rectangular output.


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## robsworld78 (Aug 14, 2014)

How many would you be comfortable putting on one strip without fan? This has more surface area than the heatsink sold at Steve's.


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## jedimasterben (Aug 21, 2011)

Without a fan? Zero. I'm not a fan of running LEDs hot, and that's a surefire way to keep them way up there.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> How many would you be comfortable putting on one strip without fan? This has more surface area than the heatsink sold at Steve's.


wise words from reef cental.. 


> 3. LED fixtures don't need active cooling if heat sink has enough surface area. This does NOT mean they need to be large. I have 36 emitters on a passively cooled 8x12x1 heat sink and it doesn't get any hotter than 90 degrees. LEDs are also more efficient when running them at less than 100%.



Sorry just dislike fans.. 

YMMV based on density and drive current..


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## jedimasterben (Aug 21, 2011)

By that logic, I can take that same size heatsink, 8x12x1, and put 36x 100 watt LEDs on it and it should stay at 90 degrees (Fahrenheit, Celsius?) without a fan. That statement gives basically no data on LED wattage, type of heatsink, surface area of the heatsink (are the fins serrated, etc), and airflow around the fixture.


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## Fissure (Jun 29, 2014)

The cooling part is a guessing game for us. I asked the one making my heatsink and in a room temp of 25 degrees celsius he calculated that for my 10 vero 18s and 50ish 3 watt leds a fixture of 1490 x 250 x 80 (W x D x H)(millimeters) would keep the hotest leds at 75 degrees at their Tj by passive convection cooling, anodizing was a must according to him to keep it passive. If the heatsink is 90 degrees then you can imagine what the Tj temp may be on the LED. Also the cooler the leds are the more lumens they produce


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## jedimasterben (Aug 21, 2011)

Fissure said:


> The cooling part is a guessing game for us. I asked the one making my heatsink and in a room temp of 25 degrees celsius he calculated that for my 10 vero 18s and 50ish 3 watt leds a fixture of 1490 x 250 x 80 (W x D x H)(millimeters) would keep the hotest leds at 75 degrees at their Tj by passive convection cooling, anodizing was a must according to him to keep it passive. If the heatsink is 90 degrees then you can imagine what the Tj temp may be on the LED. Also the cooler the leds are the more lumens they produce


Your measurements don't sound right. That heatsink would rather tiny to cool 300-400w of LEDs passively, even keeping the LEDs at such high internal temperatures.


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## robsworld78 (Aug 14, 2014)

jeffkrol said:


> 3. LED fixtures don't need active cooling if heat sink has enough surface area. This does NOT mean they need to be large. I have 36 emitters on a passively cooled 8x12x1 heat sink and it doesn't get any hotter than 90 degrees. LEDs are also more efficient when running them at less than 100%.


My question would have been how many watts were the LED's, mine can run up to 6.3w which I'm sure produces more heat than a 3w.

I guess I'll just slowly add them and see what happens. 

How long would one wait for them to get as hot as they get? Would I have to run them full 12 hours to see the heat they output?

Bump: Would this have any benifet?

I have 2 strips of aluminum, what if I put a line of thermal paste along the 1" edge and screw the 2 pieces firmly together? Would it become 1 - 1" x 4"?


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> How long would one wait for them to get as hot as they get? Would I have to run them full 12 hours to see the heat they output?


The heatsink will be saturated fairly quickly. Run them at the maximum current you plan on running them and then leave them for 10-15 minutes. If the heatsink is more than slightly warm to the touch, you need better cooling.



robsworld78 said:


> Bump: Would this have any benifet.
> 
> I have 2 strips of aluminum, what if I put a line of thermal paste along the 1" edge and screw the 2 pieces firmly together? It would become 1 - 1" x 4"


They would essentially be one piece. One of my previous heatsinks was this:










1.25" square tubing with 1/8" walls, cut and welded together, using a pressure blower fan from Steve's LEDs pushing into one of the holes.


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## robsworld78 (Aug 14, 2014)

Glad to hear that, don't want to wait all day for testing.

How did that light work out for you? Looks good! All welded right? I would think that is better than screwing, that's why I'll add the thermal paste, wish I had a welder. Are those 3w LED's?

I read Steve's retrofit kit manual for assembly, he didn't seem to worried about heat and used a lot less tubing with more LED's. That's kinda how I based what I would need.


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> Glad to hear that, don't want to wait all day for testing.
> 
> How did that light work out for you? Looks good! All welded right? I would think that is better than screwing, that's why I'll add the thermal paste, wish I had a welder. Are those 3w LED's?
> 
> I read Steve's retrofit kit manual for assembly, he didn't seem to worried about heat and used a lot less tubing with more LED's. That's kinda how I based what I would need.


It worked out well. I eventually added another dozen or so LEDs to it, didn't have many issues out of it other than the fan being a bit louder than I'd wanted (though it was because I was pushing the full 12v into it, I should have used two fans and two exhausts and ran the fans at 5v or so)

It works well when done correctly - Steve's kits use strong fans to keep the heatsinks cool. If you're running this passively using the same style tubing, you won't have pleasant results. Tube heatsinks absolutely require active cooling.


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## robsworld78 (Aug 14, 2014)

So basically I'm screwed, there's no fan going to fit on this tubing.


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> So basically I'm screwed, there's no fan going to fit on this tubing.


After having used that style of tubing, I'd say pretty much.


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## robsworld78 (Aug 14, 2014)

Well lets just hope you don't know what your talking about, lol. :hihi:


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## jedimasterben (Aug 21, 2011)

:angryfire:





:biggrin:


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## robsworld78 (Aug 14, 2014)

What size aluminum do you think would be sufficient, no fan?


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## robsworld78 (Aug 14, 2014)

This light has 72 - 3w LED's and only 46" long, also looks like it has no fan. They have an exploded view and no fan showing.

http://www.aquaticlife.com/products/3544


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## jedimasterben (Aug 21, 2011)

They've got large plate heatsinks inside of them and what looks to be an aluminum shell around them. They're passive and will be running the LEDs very hot unless there is a lot of mass (and even then, think of a heatsink like a cup, only so much heat can go into it without needing some 'poured out').


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## robsworld78 (Aug 14, 2014)

Yeah it is heavy, 28lbs. Can't wait to find out, either way I'll get some on it. UPS says by end of day tomorrow.

Is thicker plate aluminum better than tubing As in a 6" x 1/4" x 66"?


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## Fissure (Jun 29, 2014)

jedimasterben said:


> Your measurements don't sound right. That heatsink would rather tiny to cool 300-400w of LEDs passively, even keeping the LEDs at such high internal temperatures.


I am not sure tbh this was just the info i got from birmingham aluminum. I assume they know what they are talking about 

This is the answer i received from him:

*Hi John,*

*If I understand correctly you will have 13 x 36W/2 = 234W total plus 13 x 10 x 3W = 390W, so in total 624W.*

*If you use our 1850HS profile 250 mm wide x 83 mm high in a length of 1490 mm and black anodised the junction temperature between the Heatsink and LED PCB will be around 74°C in a 25°C ambient temperature with a evenly distributed load.*


This is the heatsink type

http://www.birminghamaluminium.com/heatsink_detail/107

I do hope he is not pulling my legs but i see no reason for him doing so.
This is also a high calculation. The leds will be driven far from maximum current.

Though i am not sure I would agree to call this heatsink tiny


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## robsworld78 (Aug 14, 2014)

How much?


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## Fissure (Jun 29, 2014)

Way to much. 390€ :'(


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## robsworld78 (Aug 14, 2014)

damm


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## Fissure (Jun 29, 2014)

Yeah, was looking at the makersled heatsink but with shipping from the states to Sweden it would actually have been more. Plus silver anodized would have looked crap on my tank. This hobby of friggin expensive if you have a passion for gadgets :/


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## robsworld78 (Aug 14, 2014)

Well it should be nice when finished and last long, still a lot cheaper than that one I posted at $1500 locally and will blow it away.


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## Fissure (Jun 29, 2014)

Well I have to get it all together and working first  Not sure if to drill small holes in the sink and attach the leds with short screws or use some thermal adhesive. Would prefer screws because normal thermal paste has better thermal properties than the thermal adhesives. Though I am very exited and now have to fight my lack of patience waiting for all the parts.


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## robsworld78 (Aug 14, 2014)

The adhesive is expensive but you get a cleaner install. 

I got a large tube (150g) of MG Chemicals its thermal conductivity is 0.66 W/m * K, is that good? This thing will last a lifetime. Apparently its not good to use to much so you need to be careful there.

Don't know how you can wait!


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## jeffkrol (Jun 5, 2013)

Fissure said:


> I am not sure tbh this was just the info i got from birmingham aluminum. I assume they know what they are talking about


some people aren't happy till the fans are hovering the lights above the tank.


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## gus6464 (Dec 19, 2011)

Fissure said:


> I am not sure tbh this was just the info i got from birmingham aluminum. I assume they know what they are talking about
> 
> This is the answer i received from him:
> 
> ...


That is one massive beast of a heatsink.

Bump: Have some of you not heard of Noctua fans? They are dead silent and can push some serious CFM. Pumps, filters, and just regular ambient noise are louder than these things.


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## robsworld78 (Aug 14, 2014)

They arrived, and controller should be here tomorrow although it says customs delay right now. 

I hooked one up and wow super bright, definitely need to be careful working around these, I have black spots and I didn't even look directly at it. It's sitting on the floor and casting major shadows up on my walls. In the ceiling I have 2 - 75w CFL's and it can't do anything to the shadows. Still not as bright as the CFL but major intensity. I have a feeling 26 will be to many. 

I have to say at this point I think I could run them in a line next to each other along the 66" tubing and there would be no heat. Its been running 20 minutes now and there is literally zero heat, I can easily touch the led plastic and don't even know its on.


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## robsworld78 (Aug 14, 2014)

When I hook these up I go + to + to + to + right?


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## jedimasterben (Aug 21, 2011)

No, the positive output of the driver goes to the positive of the first LED, then connect the negative of the first LED to the positive of the second LED, and so on, then the last negative connects to the negative of the driver.


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## robsworld78 (Aug 14, 2014)

lol, oh sh*t, I owe you 4 LED's and a driver. :icon_redf


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## robsworld78 (Aug 14, 2014)

One down, expect for some reason 2 LED's didn't light up, its not the driver because its lighting another one, good thing I got extras. 

It looks good, I'm happy with it. It is currently brighter than my other tank which has 2 - 54w T5HO's. After running 15 minutes there's no more heat than with one. I'm gonna let it run for 12 hours or so and see how it heats up, I think I'll just end up adding all of them to the one tube. I feel heat when I hold my hand under them so maybe most of the heat is let out that way.

The light isn't even in the picture because of wires blocking the light on the right side, when its mounted it will be 5" higher and wires cleaned up.


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## robsworld78 (Aug 14, 2014)

Well you guys called it, not enough heat sink. Its getting uncomfortable to touch. 

Damm what to do now, hmmm...


----------



## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Well you guys called it, not enough heat sink. Its getting uncomfortable to touch.
> 
> Damm what to do now, hmmm...


120F is a bit "uncomfortable" but not terrible in LED terms..If you can hold it it's not "too hot"
What is your density on that bar again and your drive current?










55C is 131F...85C is 185F 

















So first off, and in no way changes the fact that cooler is better.. but most LEd's can and do run hotter than we would like but not as to be "terribly" detrimental in the long run..at temps that may appear "uncomfortable".
To complicate it the temp of the heat sink is not indicative of the junction temp except as a guesstimate but it is the best we have.

That said, one would prefer to be able to handle the light w/out discomfort.. 

Heat loading decreases w/ decreasing current.

As to yor situation, a few thoughts.
1)fit a blower w/ mod of the rect. profile.. complicated a bit
2)drill holes .. in the bar for a)passive convection heat release or b) as ports for biscuit fans on top.
Fairly easy.
3) use a chop saw and "fin" the top w/ say 1/8 slit every 1/2 inch. w/ or without added fan support.
4)find finning to attach to the top to act as a radiator..

Of course things are a bit complicated if the LED's are glued to the bar.. 

Anyways IF one could run them ice cold it would be "Ideal" but the necessity is a bit of a real world trade off.. as the above charts show.

What can one "tolerate" in the lights performance..Can you live w/ a 10% decrease in output... ect...

not always black and white..

50,000hrs is 17 years at 8hr/day......

reference:
http://www.sekhmet.co.kr/LED_press_room/LED_technical.html

Oh and if you need to change the end profile from rec to round a PVC pipe reducer (or expander might work. A bit of filling in ect and a bit crude.. but doable.
Putting a square hole on a rect. one is not too difficult though..


----------



## jeffkrol (Jun 5, 2013)

Interesting addendum:


> Cost Justification for LED Lamps
> 
> Since LEDs are current driven, each degree the ambient temperature rises it affects the Based LED's (including its components) operating temperature. In order to maintain the projected longevity (100,000 hours) of the Based LED, the Based LED and its components should be redesigned to operate within the nominal desired operating temperature range of 35°C - 45°C.
> 
> ...











http://www.ledtronics.com/TechNotes/TechNotes.aspx?id=22

Smaaaaaaall LEd's but concept is a bit the same..

About that guessitimate from the heatsink temp..


> Graph 1 shows an ideal LED current verses temperature relationship. Up to the manufacturer’s specified maximum operating temperature, the LED current remains constant. As the LED temperature exceeds the limit, the current and therefore the power is reduced and the LED dimmed to protect it from overheating. This curve is called a “Derating Curve” and keeps the LED working within its safe power dissipation limits. The 55°C “threshold” temperature in the above graph is the base plate or heat sink temperature – *the LED itself will be typically 15°C warmer (i.e. 70°C) and the internal junction temperature close to 35°C warmer (i.e. 90°C). Thus 55°C is thus a safe full power limit*, although it could be increased to a maximum of 65°C for high performance LED lamps


http://ca.mouser.com/applications/lighting-derating/

Check the real temp of your heat sink...IF it is below 131F.. you are "fairly" safe albeit w/ some "long" term minor damage possible..Your power supply will fail long before the LED's will.. 

Reference:
http://www.mouser.com/pdfdocs/lumiled-understanding-led-performance.pdf



> For the MFR 4 emitter, these
> operating conditions are consistent with the lumen
> maintenance conditions: the device is able to provide
> 50,000 hours of use at a junction temperature of
> ...


135C is 275F


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## robsworld78 (Aug 14, 2014)

Thanks for all the info, I appreciate it! I ran them again for about 2 hours and I could hardly touch it so its no good, I don't want it running that hot even if it was ok.

There's 10 LED's lite up, they were running at 6.3w @ 700ma, they are rated for 9w @ 1000ma.

I got the controller today so I'll turn it down some and see what happens. I'll also run less LED's till I know what works and go from there I guess.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Thanks for all the info, I appreciate it! I ran them again for about 2 hours and I could hardly touch it so its no good, I don't want it running that hot even if it was ok.
> 
> There's 10 LED's lite up, they were running at 6.3w @ 700ma, they are rated for 9w @ 1000ma.
> 
> I got the controller today so I'll turn it down some and see what happens. I'll also run less LED's till I know what works and go from there I guess.


Yea, that a lot of watts for that type of heat sink..


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## gus6464 (Dec 19, 2011)

Wait so why didn't you go with a finned plate heatsink? Also I don't know why so many people are against fans. You can get very high quality fans (Noctua) that are dead silent and push tons of air. You can even get PWM versions that hook up directly to your arduino so you can control the speed so when your lights are off so is the fan and have it ramp up as you crank the light.


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## Fissure (Jun 29, 2014)

gus6464 said:


> Wait so why didn't you go with a finned plate heatsink? Also I don't know why so many people are against fans. You can get very high quality fans (Noctua) that are dead silent and push tons of air. You can even get PWM versions that hook up directly to your arduino so you can control the speed so when your lights are off so is the fan and have it ramp up as you crank the light.


Visible fans are not very nice to look at in a well decorated home 
The DIY solutions also looks crude at best where i have seen fans. And moving air always make a sound no matter how good the bearings or blade design are. 
Other than that there is no reason do dislike fans!


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## jeffkrol (Jun 5, 2013)

Fissure said:


> Visible fans are not very nice to look at in a well decorated home
> The DIY solutions also looks crude at best where i have seen fans. And moving air always make a sound no matter how good the bearings or blade design are.
> Other than that there is no reason (to) dislike fans!


LOL.. that seems to infer there is not much reason to like them either.. 










SORRY, just for fun................ 

and in the spirit of fairness...


> With all these issues, is there any reason at all to consider active cooling? The answer is yes, given how LEDs can supply light. Many LEDs can increase light output with additional current input, until the point of current saturation. Today, the most costly parts of an LED system are the LEDs themselves. If one can reduce the LED count by driving the LEDs with higher currents, then the system cost can be sharply reduced. Adding cost with an active cooling system can actually reduce the overall system cost by lowering the LED count. Hence a good active cooling system is an advantage, when it is designed properly, which means it must be efficient, quiet, reliable, and cost effective.
> 
> *Summary*
> LEDs are changing the world of lighting due to their efficiencies, size, durability, and lifetime cost. One of the key changes in lighting system design is adapting to a primarily conduction-based heat transfer design within the system, followed with an adequate convection design to the ambient air. This will require new designs of the LED system and the lighting fixture designs that will act differently than previous generations of lighting where radiation played a dominant role. The challenges to develop new systems of passive and active cooling will keep LED and lighting designers busy for the foreseeable future.


http://www.electronics-cooling.com/2006/11/thermal-challenges-in-led-cooling/

Reference:
http://www.electronics-cooling.com/2005/11/advances-in-high-performance-cooling-for-electronics/


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## robsworld78 (Aug 14, 2014)

gus6464 said:


> Wait so why didn't you go with a finned plate heatsink?


I thought the tubing would be enough. I was looking at Steve's retrofit kits and based it off of that. I wish I would have asked you guys first. I don't know what I'm gonna do, I can't be spending $350 on a heat sink.

LED's aren't that great, what's the point of being so small if you need a massive heatsink???? Just make the damm LED bigger so it can handle its own heat.

jeffkrol those last links don't work.


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> I thought the tubing would be enough. I was looking at Steve's retrofit kits and based it off of that. I wish I would have asked you guys first. I don't know what I'm gonna do, I can't be spending $350 on a heat sink.
> 
> LED's aren't that great, what's the point of being so small if you need a massive heatsink???? Just make the damm LED bigger so it can handle its own heat.
> 
> jeffkrol those last links don't work.


You missed the very important part of Steve's kits in that 100% of them are actively cooled with at least one strong pressure fan.

If you don't want to pay the money for a plate heatsink, then you'll need to come up with a pressure fan that can push through what you have. Or, purchase 1.25" aluminum tubing with at least 1/8" walls like Steve's uses and then buy some of their fans and use them.

Would you rather the LEDs be small and have one cooling solution for an entire array or have large, single LEDs and having to deal with multiple cooling solutions?


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## Fissure (Jun 29, 2014)

jeffkrol said:


> LOL.. that seems to infer there is not much reason to like them either..
> 
> 
> 
> ...


Hehe that is a cute fan. Fans are good for many things and in some cases necessary. I do not have any form of fanhatred but i personally just don't want a bunch on my tank. Especially when the girlfriend already thinks there is to much noise  

For the thread creator i think it is a necessity. Highpowered leds on a hollow piece of aluminum wont work, the heat buildup inside the profile will be pretty bad.


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## gus6464 (Dec 19, 2011)

robsworld78 said:


> I thought the tubing would be enough. I was looking at Steve's retrofit kits and based it off of that. I wish I would have asked you guys first. I don't know what I'm gonna do, I can't be spending $350 on a heat sink.
> 
> LED's aren't that great, what's the point of being so small if you need a massive heatsink???? Just make the damm LED bigger so it can handle its own heat.
> 
> jeffkrol those last links don't work.


You don't need a massive heatsink, you just need a properly designed fixture.

Steve's LEDs uses a very high pressure fan with his tubes to dissipate the heat inside the tube. You missed the most important part of his design.

An LED is a semiconductor. You can't beat the laws of physics.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> jeffkrol those last links don't work.


They worked fine for me one 2 different systems..
Anyways a chart for fun: It is def. "dated" though (2006):











> Cree, Inc. (Nasdaq: CREE) records another significant LED milestone with the demonstration of 303 lumens per watt from a white, high-power LED.


http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/March/300LPW-LED-barrier

Currently:


> According to the company, cold forging produces heat sinks that have better heat dissipation than die-casting and aluminum extrusion. The Igloo FR210 and Igloo FR210HP are fitted with AL1050 aluminum, meaning that thermal conductivity can be increased 2.36 times compared to die casting: 96.2 W/mK to 227 W/mK.


http://www.electronics-cooling.com/2014/08/cold-forged-heat-sinks-boost-thermal-management-leds/

http://www.electronics-cooling.com/2013/12/heat-sink-correlations-design/

Sorry.. just having some fun at that site:


> "Zeta LED has developed an air-cooled LED light bulb. The Lifebulb consumes 10 watts of power and puts out as much light as a standard 60 watt incandescent, pretty much like existing LED bulbs. The difference comes in the absence of an aluminum heat sink.
> 
> Zeta keeps its bulb cool by channeling air through the vents in the structure itself: the vents are the strips and holes separating the yellow LED arrays. The bulb does not come with a covering glass dome as air wouldn’t circulate if the electronics were completely covered. "


http://www.electronics-cooling.com/2012/04/cooling-leds-with-air-instead-of-heat-sinks/

Polycarbonate heat sinks:
http://www.materialscience.bayer.co...ations/inspiration-gallery/led-heat-sink.aspx
such a young industry..


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## robsworld78 (Aug 14, 2014)

> Today, the most costly parts of an LED system are the LEDs themselves. If one can reduce the LED count by driving the LEDs with higher currents, then the system cost can be sharply reduced. Adding cost with an active cooling system can actually reduce the overall system cost by lowering the LED count. Hence a good active cooling system is an advantage, when it is designed properly, which means it must be efficient, quiet, reliable, and cost effective.


That statement is so out of date, my 26 LED's for the system only cost $122 and now I need $500 to keep it cool. I'm better off running 52 LED's at 25% power and no fancy heatsink.

I was looking at small heat sinks at mouser to add on top of the tubing but there like $15 - $20 for 3". 

I was pretty sure I read somewhere on Steve's site it said a fan wasn't really necessary, guess I imaged it.

I've got all 13 LED's working on the bar now and have the controller hooked up. At 20% it only gets warm, I'm running it at 40% now and its starting to get hot. That will probably be the limit. I think with 13 more LED's running at the same level I'll have plenty of light still.


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> That statement is so out of date, my 26 LED's for the system only cost $122 and now I need $500 to keep it cool. I'm better off running 52 LED's at 25% power and no fancy heatsink.
> 
> I was looking at small heat sinks at mouser to add on top of the tubing but there like $15 - $20 for 3".
> 
> ...


Your thinking is quite backwards. At 40% across 26x LEDs, I think your LEDs are like 9v right? And on 1A drivers? If so, that's 400mA x 9v = 3.6 watts each, times 26 is 93.6 watts. Adding 13x more LEDs and running them at 400mA as well will put you at 140.4 watts, increasing heat load by an additional 46.8 watts.

If I got your LED amperage and voltage wrong, then insert your proper numbers and you'll see that adding more LEDs at lower current won't work, as they're not really gaining the extra efficiency you need to match the output of your LEDs at 100% without a lot of extra heat.


EDIT: Ok, I see what you are saying now - you have 13x LEDs running and at 700mA (91 watts) and it's too hot. You are going to run all 26 LEDs at 280mA (40%), which puts you around 65 watts with a few hundred lumens less output.


This seems like an awfully tiny amount of light for a 72x18x22 tank.


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## robsworld78 (Aug 14, 2014)

jedimasterben said:


> Your thinking is quite backwards.


LOL, it has its benefits. 

I meant adding 13 more on another piece of tubing, no more on this tube. If I added 4 tubes with 13 LED's each and ran them at 25% that would be cheaper than running 13 full power with proper cooling.

These are running at 700ma (driver full power), they can handle 1amp.



> You have two temperature related pain sensors in your skin, called the VR1 and VR2 pain receptors. VR1 kicks on at about 43 to 45 deg C for most folks, which is below the point where damage to your skin occurs. VR2 kicks in at about 50 or 51 deg C, where damage actually does occur. Between roughly 43 to maybe 48 deg C is the range where you really, really, really want to move your hand away, but it won't cause any physical damage to your skin.


If this is accurate than I'm not even close to pushing them in temperature, never once have I had to really really move my hand away. Sure this isn't the contact point I'm feeling but I can get pretty close.

Fissure you mentioned on your thread that your LED's will run at about 75 so that won't that get the heat sink over 55 which means you'll burn yourself handling it? I'm certain I read a quote about temps from the manufacture that you posted on your thread but can't find it now?


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## jedimasterben (Aug 21, 2011)

See my edit


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## robsworld78 (Aug 14, 2014)

They've been running at 40% for over an hour now, I can squeeze the tube all day, nice and warm but no pain. I just turned it to 50%.

If I do 50% that 350ma at 9v = 3.15w x 26 LED's = 82 watts

or lumens

Based on Cree's data sheet @ 400ma (close enough) running at 85c. The lumens are from my exact part numbers.

2700k = 220lm x 8 LED's = 1,760 lumens
6500k = 440lm x 18 LED's = 7,920 lumens

Total Lumens = 9,680 or there about

You don't that that's equivalent to 2 - 54w T5HO on a 4ft tank same depth?


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## robsworld78 (Aug 14, 2014)

It would be twice as bright.


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## robsworld78 (Aug 14, 2014)

Also isn't the point of LED's to run less watts?


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> It would be twice as bright.


Pretty much. Someone at an Orchid growing site did some measurements and number crunching to compare LEd's to T5's Numbers showed LED equivalency was 1/3 to 1/2 W LED vs 1W T5...

Others have verified this "guessitmate"... of course nothing beats actual measurements of an actual light... 

Bump:


robsworld78 said:


> Also isn't the point of LED's to run less watts?


Or double your light w/ the same watts..


----------



## robsworld78 (Aug 14, 2014)

My 2 cents is high powered LED's aren't ready for the real world yet, at least indoors. 

After running at 50% the tube got where I could hardly touch it, went back down to 40% and it cooled some so I feel 40% is my limit passive.

I went through my junk and found a small 1.75" square fan and decided to give it a try. I made a connector using cardboard which seals well and added it to the tube. The air makes it down the tube nicely and lots of heat blows out. Sure enough it works, I ran at 70% for 45min and it was cooler than 40% without fan. I'm now running at 100% and think it will be ok.

But now my room temperature has gone up a full 2 degrees and rising as this fan is blowing heat, its like a small heater. Just as if it was an HPS light. It'll be ok for the winter but now I'll need an air conditioner for the summer to combat the light. 

It seems to me large amounts of high powered LED's isn't a good idea as there is just to much heat. T5HO's have them beat IMO as they are still cheap to run and no heat. I think it would have been better to go with a ton of 1w or less and have no heat.


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## robsworld78 (Aug 14, 2014)

jeffkrol said:


> Or double your light w/ the same watts..


Don't forget about the fishes.


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> My 2 cents is high powered LED's aren't ready for the real world yet, at least indoors.


Tell that to Philips, Cree, and every other LED manufacturer that is mass producing chips for interior lighting 



robsworld78 said:


> But now my room temperature has gone up a full 2 degrees and rising as this fan is blowing heat, its like a small heater. Just as if it was an HPS light. It'll be ok for the winter but now I'll need an air conditioner for the summer to combat the light.
> 
> It seems to me large amounts of high powered LED's isn't a good idea as there is just to much heat. T5HO's have them beat IMO as they are still cheap to run and no heat. I think it would have been better to go with a ton of 1w or less and have no heat.


Your logic is backwards. Every watt of power you use ends up as heat no matter what kind of light you choose, that's the law of conservation of energy in play. If you have 100 watts of LED light or 100w of T5 or MH you will output 100w heat from all of them, except with T5 and MH you get around half the light per watt.


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## jeffkrol (Jun 5, 2013)

Best current estimated based on your LED's give output at 108lm/w. For t5HO that is about 87lm/w.. Now lumens isn't a particularly good measurement for plant lighting. Matter of fact if one takes into account the spectrum, LED efficiency comes to 1/2W is = to 1w of T5HO. (arguable).

From below you need to understand that the flour. produces different forms of heat, not less...Granted the sum of the "heat" between flour. and LEd's is not much different 
w for w there is not much difference. One is not cooler or warmer than another..
http://www.britegate.com/index.asp?p=/static/compare_led_vs_fluorescent_light.html


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## robsworld78 (Aug 14, 2014)

jedimasterben said:


> Every watt of power you use ends up as heat no matter what kind of light you choose, that's the law of conservation of energy in play. If you have 100 watts of LED light or 100w of T5 or MH you will output 100w heat from all of them, except with T5 and MH you get around half the light per watt.


That can't be true, I have 108w of T5's going now and there is no heat or very little, I have 58w of LED's going and heat is crazy.

Also if I used low output LED's and used enough to add up to 100w there would be no heat, not like this.


----------



## jedimasterben (Aug 21, 2011)

robsworld78 said:


> That can't be true, I have 108w of T5's going now and there is no heat, I have 58w of LED's going and heat is crazy.
> 
> Also if I used low output LED's and used enough to add up to 100w there would be no heat, not like this.


So where is that energy going, then?


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## robsworld78 (Aug 14, 2014)

I don't know maybe in the light, all I do know is 108w of T5 is much much cooler than 58w of high powered LED's.


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## jedimasterben (Aug 21, 2011)

108w of power is 108w of power, 58w of power is 58w of power.


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## robsworld78 (Aug 14, 2014)

I guess my thermometer is wrong then.

Is there 50lbs of heatsink in a T5 fixture?


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## jedimasterben (Aug 21, 2011)

If you're checking with a thermometer, say, right above the LED heatsink or touching it, you're going to find it reads higher. Fluorescent bulbs spread their heat over their length (along with their light output), so while you may think that nearly double the heat output is less overall, it is far from it. Double the heat is double the heat.


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## robsworld78 (Aug 14, 2014)

Sure my t5's are 4ft, this is 6ft, longer and hotter! The heat is even along the 6ft tube.

I don't need a thermometer, I can feel the heat radiate off it, can't feel that from my t5's.


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## jedimasterben (Aug 21, 2011)

Can't beat physics.


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## robsworld78 (Aug 14, 2014)

Agree to disagree.  I don't need physics to tell me when something is warm or putting of heat. 

If I turn something on in a room and the thermometer starts to rise and I start warming up I know its putting off heat.


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## robsworld78 (Aug 14, 2014)

Do you have anything I can read? This is bugging me, maybe I am wrong. 

When CFL's came out the big thing was they burn cooler the incandescent. I run the same real wattage and the CFL is cooler?


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## robsworld78 (Aug 14, 2014)

These are cool images. By the first image it appears design has a lot to do with it. The higher powered LED is the coolest. Maybe with enough heatsink the heat disipates to nothing?


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## gus6464 (Dec 19, 2011)

Funny how I can cool 150W of LEDs on a 24x4.8x0.8" heatsink with one very silent fan and generate not much heat. Ohh and the heatsink weighs 3.12 lbs.

Bad fixture design can't beat the laws of physics.


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## robsworld78 (Aug 14, 2014)

How many watts are you driving each LED at? That obviously makes a big difference. Those Vero's must put out major heat as so many watts in such a small package.

What makes it all so confusing and why I disagree with jedimasterben is if I had 156 - .5w LED's running this tube would be a lot cooler correct? But why with 13 - 6w LED's is almost red hot? So based on that 78w isn't 78w? There can be very different types of 78w which produces different levels of heat.

Bump:


gus6464 said:


> Funny how I can cool 150W of LEDs on a 24x4.8x0.8" heatsink with one very silent fan and generate not much heat. Ohh and the heatsink weighs 3.12 lbs.
> 
> Bad fixture design can't beat the laws of physics.


I have a feeling if you removed the LED's you have and added 150w worth of Veros you would overheat, which leads me back to the same watts can put out different levels of heat.

EDIT: Maybe this is why there isn't any fixtures with more than 3w LED's in them as its just to hard to cool? Think that's possible?


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> What makes it all so confusing and why I disagree with jedimasterben is if I had 156 - .5w LED's running this tube would be a lot cooler correct? But why with 13 - 6w LED's is almost red hot? So based on that 78w isn't 78w? There can be very different types of 78w which produces different levels of heat.


No matter what kind of heatsink you have or how quickly the heat is dissipated from it, heat wattage is heat wattage, and it always goes somewhere. The reason your single exhaust feels so dang hot is because it's the only place that heat can go and is all concentrated in that single 1x2 output. It feels a lot hotter than if you had a plate heatsink with fins of the same dimensions that had 3-4x fans blowing onto it, but the reality is that you're still putting out the same wattage of heat, just over a larger area, making it seem like it would be less hot, though it is not.


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## gus6464 (Dec 19, 2011)

You mean these Vero?










Those are Vero 18's on my fixture. Ohh and I could push way more than 150W if I wanted to would just need to add more fans.

The 24" heatsink that I wrote about above has 4 nanobox pucks. Each puck is 35W at full power in a 1.5" sq inch MCPCB.


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## robsworld78 (Aug 14, 2014)

I believe this image also says something, to me it does. Look at the bases of them, they are all smoking hot, coolest is 69c and this is the area where the heatsink is. So its obvious the manufactures use a heatsink that will keep the LED under 85c the limit. Good LED bulbs they go for cooler for obvious reasons. 

So if those heatsinks are 80c then the LED contact point can't be much higher. Even so the heatsinks are 80c so lets go with that.

My thinking then says that my tube should be able to get to at least 70c and there would be no issues (other than possible melted wires) with the LED's. If that's correct then mine could be built bang on. I like tools so I think I'm gonna get a temp reader and see what it gets to on high. I've also seen a couple DIY that claimed they got to hot to touch but worked for years without issues. Just like the household bulbs get to hot to touch at least the heatsink, the top can be touched.

Bump:


jedimasterben said:


> No matter what kind of heatsink you have or how quickly the heat is dissipated from it, heat wattage is heat wattage, and it always goes somewhere. The reason your single exhaust feels so dang hot is because it's the only place that heat can go and is all concentrated in that single 1x2 output. It feels a lot hotter than if you had a plate heatsink with fins of the same dimensions that had 3-4x fans blowing onto it, but the reality is that you're still putting out the same wattage of heat, just over a larger area, making it seem like it would be less hot, though it is not.


Ok fair enough but why those low power LED's no heat, I can run 100's of them?

Bump:


gus6464 said:


> You mean these Vero?
> 
> 
> 
> ...


Looks good! Where are the wires? If you turn the fan off how hot does it get?


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## gus6464 (Dec 19, 2011)

I don't think you understand what an LED is. An LED is not a light bulb, its a semiconductor. A semiconductor requires some form of heat exchange to cool, hence heatsinks. The bigger the exchanger (heatsink), the better cooling efficiency. Now because of the surface are required to cool high wattage semiconductors passively would be huge, forced induction (fans) is introduced to take all the excess heat from the exchanger so that you can have a smaller heat exchanger surface area.

By using those tubes you started with a tiny heat exchange surface area to begin with which obviously cannot cool that much wattage passively. You remedy that by adding a high cfm fan that can push all that excess heat away from the exchanger. The bigger the exchanger surface area, the less excess heat it will put out. You are getting a huge spike in room temp because you started with a puny exchanger which is putting out a ton of excess heat and it has to go somewhere.

Properly cooling a semiconductor is a balancing act. Proper design finds that balancing act. You go massive exchanger if you want passive cooling, but if you can't go that big then you introduce forced induction to take care of expelling the excess heat the exchanger cannot handle.

Bump:


robsworld78 said:


> I believe this image also says something, to me it does. Look at the bases of them, they are all smoking hot, coolest is 69c and this is the area where the heatsink is. So its obvious the manufactures use a heatsink that will keep the LED under 85c the limit. Good LED bulbs they go for cooler for obvious reasons.
> 
> So if those heatsinks are 80c then the LED contact point can't be much higher. Even so the heatsinks are 80c so lets go with that.
> 
> ...


The molex connectors are not on there yet in that pic but they are routed on the other side. If I turn off the fans it gets hot real quick. I have no need to run passive and kill my LEDs quicker so I just run fans.

And also 100W of 0.5W LEDs is the same exact thing as 100W of a 100W LED. Wattage is wattage. You also wouldn't be able to fit 100W's worth of 0.5W LEDs on that heatsink of yours.


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## jedimasterben (Aug 21, 2011)

gus6464 said:


> The bigger the exchanger surface area, the less excess heat it will put out. You are getting a huge spike in room temp because you started with a puny exchanger which is putting out a ton of excess heat and it has to go somewhere.


This is not correct - the heat put out into the room will be higher no matter what, as the heatsink is only holding onto it until the fan can blow it off, the heat load is always the same.


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## robsworld78 (Aug 14, 2014)

I know an LED is not a bulb, I said bulb because we turn them into the term "bulb". 

I understand what you are saying and yes before I added the fan my room temp didn't climb because I wasn't forcing out the concentrated hot air. 

My second point with the "bulbs" is that heatsink reaching temperatures of 70c is ok so our heatsink should also be able to get to 70c with no damage to the LED's.

Bump:


jedimasterben said:


> This is not correct - the heat put out into the room will be higher no matter what, as the heatsink is only holding onto it until the fan can blow it off, the heat load is always the same.


I would think so to but honestly as soon as I hooked up that fan my room temp started climbing. It was running hours hot without the fan and I didn't notice it, only a bit when I opened the canopy. After adding the fan when I opened the canopy it was very warm in there.


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> I would think so to but honestly as soon as I hooked up that fan my room temp started climbing. It was running hours hot without the fan and I didn't notice it, only a bit when I opened the canopy. After adding the fan when I opened the canopy it was very warm in there.


Think of the heatsink like a sponge. You can keep putting more water (or heat) onto it and it will continue to hold it. If you wring it out (or add a fan), then all of that water (heat) leaves.


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## robsworld78 (Aug 14, 2014)

gus6464 said:


> The molex connectors are not on there yet in that pic but they are routed on the other side. If I turn off the fans it gets hot real quick. I have no need to run passive and kill my LEDs quicker so I just run fans.


Ah, it looked to impossible.  That's what I wanted to hear with the heat, something like my situation although your heatsink does look better. What is it in the picture?

Now I don't think running passive would hurt your LED's if the heatsink stays under 70-80c, what do you think about that? Obviously its better with the fan and you being able to the touch the heatsink but those "bulbs" run high and last long?



gus6464 said:


> And also 100W of 0.5W LEDs is the same exact thing as 100W of a 100W LED. Wattage is wattage. You also wouldn't be able to fit 100W's worth of 0.5W LEDs on that heatsink of yours.


Hmmm, I was thinking about those strip LED's, 5050 or something. I saw some build on here, guy used tons of them, used a par meter to prove results and had no heatsink. I was thinking that route after seeing it but like the high powered ones plus I'm quite skeptical of those little guys for growing plants.

Bump:


jedimasterben said:


> Think of the heatsink like a sponge. You can keep putting more water (or heat) onto it and it will continue to hold it. If you wring it out (or add a fan), then all of that water (heat) leaves.


Yeah your right and I haven't run it yet with the fan on from the get go which will probably make it so the tube never really heats up and I don't feel that hot exhaust.

Bump:


gus6464 said:


> The bigger the exchanger surface area, the less excess heat it will put out. You are getting a huge spike in room temp because you started with a puny exchanger which is putting out a ton of excess heat and it has to go somewhere.


I agree with that. When I had just one LED on this tube it was cold meaning the heat was dissipated and never had a chance to enter the air. If the heatsink was big enough it wouldn't warm up so the air around it wouldn't warm either.


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## gus6464 (Dec 19, 2011)

jedimasterben said:


> This is not correct - the heat put out into the room will be higher no matter what, as the heatsink is only holding onto it until the fan can blow it off, the heat load is always the same.


The bigger the surface area of the exchanger, the better the dissipation. One can test this easily by taking a big heatsink and putting 2 different heat sources on it. For example a 0.5W SMD LED on a big plate heatsink will have 100% dissipation within the exchanger vs a 10W LED. Hence why the heatsink with the 0.5W chip will be cold to the touch vs the 10W chip and will put out no excess heat requiring forced induction to cool the exchanger.


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## jedimasterben (Aug 21, 2011)

robsworld78 said:


> Now I don't think running passive would hurt your LED's if the heatsink stays under 70-80c, what do you think about that? Obviously its better with the fan and you being able to the touch the heatsink but those "bulbs" run high and last long?


If the heatsink is 70-80C, then the LED die will be much hotter, usually 10-20C depending on the LED C/W, PCB C/W, and heatsink C/W. An LED run at 40-50C, which is typical of a well-cooled array, will last far longer and output much more light than those run 90C+.



robsworld78 said:


> Hmmm, I was thinking about those strip LED's, 5050 or something. I saw some build on here, guy used tons of them, used a par meter to prove results and had no heatsink. I was thinking that route after seeing it but like the high powered ones plus I'm quite skeptical of those little guys for growing plants.


The issues with 5050 and those other generic chinese strips are numerous - color, color consistency, output, output consistency, efficiency, etc. In addition, the amount that you need to use to have a decent array output capable of high light gets ridiculous quickly.



robsworld78 said:


> Yeah your right and I haven't run it yet with the fan on from the get go which will probably make it so the tube never really heats up and I don't feel that hot exhaust.


It will still exhaust the same amount of heat as before, because that is how much heat the LEDs are putting out.

Bump:


gus6464 said:


> The bigger the surface area of the exchanger, the better the dissipation. One can test this easily by taking a big heatsink and putting 2 different heat sources on it. For example a 0.5W SMD LED on a big plate heatsink will have 100% dissipation within the exchanger vs a 10W LED. Hence why the heatsink with the 0.5W chip will be cold to the touch vs the 10W chip and will put out no excess heat requiring forced induction to cool the exchanger.


The dissipation is better, but the heat load remains the same for the same wattage and so that same amount of heat will still be transferred to the surrounding environment. I'm on your side


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## robsworld78 (Aug 14, 2014)

So what do you guys do when your on vacation the cooling fan dies and your LED's overheat? How do you know the heatsink won't climb past an unsafe limit? Have you tested that? A proper design should be able to cool the LED's enough passively without damage and then add air to run optimum.


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## gus6464 (Dec 19, 2011)

Here is a good example, the Sicce GNC AMC 466. This thing has 466 tiny LEDs for a total of 120W which is cooled passively.










Now look at the massive size of the heatsink which cools it.


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## robsworld78 (Aug 14, 2014)

That is a good example, I like the look of the heatsink.  

So how do you know yours won't overheat if the fan dies? You said it gets really hot quick. What if its running 8-10 hours with no fan?

And be honest, did you plan to run without fans and realize after that wasn't going to happen?


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## gus6464 (Dec 19, 2011)

robsworld78 said:


> That is a good example, I like the look of the heatsink.
> 
> So how do you know yours won't overheat if the fan dies? You said it gets really hot quick. What if its running 8-10 hours with no fan?
> 
> And be honest, did you plan to run without fans and realize after that wasn't going to happen?


No I always put fans in my fixtures. I like to overcool my stuff so I actually ran 5 fans in the Vero fixture.

4x 120mm
1x 200mm

I could run the thing at 200W and it would be cold to the touch. Also this helps as backup as there is no way 5 fans are dying at once.


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## robsworld78 (Aug 14, 2014)

That sounds good, least you're covered if one dies, that's what I was wondering. Do you have a picture of how you added your fans?


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## jedimasterben (Aug 21, 2011)

gus6464 said:


> No I always put fans in my fixtures. I like to overcool my stuff so I actually ran 5 fans in the Vero fixture.
> 
> 4x 120mm
> 1x 200mm
> ...


There is no such thing as cooling overkill. I just wish there was something I could do with my Nanobox housing over my reef. The heatsink is 1.9"x34" and is like 1" tall, so it doesn't have a lot of mass, and the largest fans that can be used are 50x50x10mm, which don't exactly have a lot of output. But that's what happens when you want a small fixture


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## gus6464 (Dec 19, 2011)

robsworld78 said:


> That sounds good, least you're covered if one dies, that's what I was wondering. Do you have a picture of how you added your fans?


I took down the light for a remodel as it's now being converted to reef. But basically I made a top for it and cut holes on it and mounted the fans on it.

Bump:


jedimasterben said:


> There is no such thing as cooling overkill. I just wish there was something I could do with my Nanobox housing over my reef. The heatsink is 1.9"x34" and is like 1" tall, so it doesn't have a lot of mass, and the largest fans that can be used are 50x50x10mm, which don't exactly have a lot of output. But that's what happens when you want a small fixture


Yeah it's all trade-off which sucks. How hot does your fixture get?


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## robsworld78 (Aug 14, 2014)

...


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## jedimasterben (Aug 21, 2011)

gus6464 said:


> Yeah it's all trade-off which sucks. How hot does your fixture get?


If I run everything at 700mA, the LEDs use around 199 watts including LDD and HLG inefficiencies, bumped up to 1A that goes up to 273 watts. The heatsink with them at 700mA gets around 45C, at 1A that climbs to ~60C, which is too hot. I don't max out any of the channels, the most I use is 600mA on royal blue, the rest are at 500mA peak on a parabolic dimming setting.

With all LEDs at full bore and both T5 lamps on, I get just over 400 PAR on the sandbed


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> Do you have anything I can read? This is bugging me, maybe I am wrong.
> 
> When CFL's came out the big thing was they burn cooler the incandescent. I run the same real wattage and the CFL is cooler?


Well the catch is that your "real" watts/output was lower w/ them .. Which is why they ran "cooler"..

A REAL 60W that ran at 60W CF w/ produce much the same heat (ignoring the higher light l/w efficiency for now) as a 60W incandescent..
BUT will be MUCH brighter than that.. Go to a store and look at a 65W CF yard light vs. a 60 "bulb" ..



> *GE Reveal *
> 
> * Model # FLE13HT3/2/RVLCD*
> 
> ...


Says it all....
http://www.homedepot.com/p/GE-Revea...ight-Bulb-1-Pack-E-FLE13HT3-2-RVLCD/202514271

A real 65W CF light. 
http://www.homedepot.com/p/Unbranded-65-Watt-White-Fluorex-Fluorescent-Yard-Light-9165/100141834


> Uses 65 watt with 500 watt output.


If you want you could see how warm your house gets w/ a 500w incandescent type bulb.. 

5/100w bulbs would do w/ a small fan blowing across them..


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## robsworld78 (Aug 14, 2014)

Do you think a 3/4" x 3/4" 16 gauge square aluminum tube 66" long be enough to cool 6 moonlight led's without a fan? They would run at 350ma max, 1.15w each.

http://www.lowes.ca/metal-products/steelworks-6-ft-l-x-34-in-w-x-34-in-h-aluminum-plain-square-tube_g1342861.html

http://www.rapidled.com/royal-blue-moonlight-led/

EDIT: Forget it, I can put them on the same heatsink I have already, they won't be on when the others are.


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## robsworld78 (Aug 14, 2014)

gus6464 said:


> You can get very high quality fans (Noctua) that are dead silent and push tons of air.


Look what I found on my journey, big enough box for such a small fan, these are 40mm.


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## jedimasterben (Aug 21, 2011)

Lol


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## robsworld78 (Aug 14, 2014)

These should last longer than the LED's.


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## robsworld78 (Aug 14, 2014)

All done, except for the moonlights, they didn't have any 350ma drivers so later I guess. Any chance I can wire 2 some how so they each get 350ma from a 700ma driver?

I'm not impressed with the Noctua fans, they don't move that much air, the Chinese one I was using pushes 3 times the air at least, same size fan, but 10 times louder. With the noctua's the air is still making it all the way down the tube and so far so good.

It's to bright at 100% so I'll probably be running around 70%.

Here's some pics of the build.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> All done, except for the moonlights, they didn't have any 350ma drivers so later I guess. Any chance I can wire 2 some how so they each get 350ma from a 700ma driver?


wire 2 in parallel..

Voltage adds in series.. Amps add in parallel..


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## letoan (Aug 7, 2012)

robsworld78 said:


> So what do you guys do when your on vacation the cooling fan dies and your LED's overheat? How do you know the heatsink won't climb past an unsafe limit? Have you tested that? A proper design should be able to cool the LED's enough passively without damage and then add air to run optimum.


Use something like arduino with a temp sensor as a controller and have it dim down/shutdown/alarm/control fan duty according to your desires temp tresholds.

@jedimasterben
Didn't know you're into planted tank too. How's the shallow reef coming along?


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## robsworld78 (Aug 14, 2014)

That's cool I can use a 700ma driver, I got extras.

Those fans are useless unfortunately, only keeps the first foot or so cool and at the end it gets very hot. So I did what I didn't think I could do, I put a 4 1/2" fan on the end. Bent up some box board and made a dual outlet adapter. 

The Fan I had laying around doesn't push as much air as I thought it would but very quiet, can't hear it standing 2 feet away and under the canopy impossible. Its pushing enough to force lots of air out of each of the holes along the tubing, however this still isn't enough, at 100% it still gets very hot. It works fine for 80% but I'll probably add another large fan on the other side, it should be able to run at 100% without heat issues even though I don't need that much light.

So if I learnt one thing (I learned lots) through this it would be not to underestimate how hot LED's get. I definitely like the look of the light LED produces and when this is running at 100% my whole living room lights up.  I'm glad I went this route.

26 - 9w Cree LED's - $156 (running at 6.3w each)
7 - Meanwell LDD-700HW Drivers - $56
2 - 1"x2" Rectangular Aluminum Heatsink - $70
2 - Noctua 40mm Fans - $29
Coralux Storm LED Controller - $75
Wire - $15
Wire Organizer Strip - $12
Thermal Paste - $12
Disconnects - $7
Screws / Washers - $4

*Total - $436*

Thanks for all the help everyone has given, couldn't have done it without that.


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## jeffkrol (Jun 5, 2013)

robsworld78 said:


> That's cool I can use a 700ma driver, I got extras.


Just be aware that "if" one fails open, the remaining one will get all 700mA...
Most that run parallel fuse the end (1/2A fuse is probably good in this case) as a precaution on losing both in this event....

One of the gotchas of parallel LED design..

Out of curiosity , why did you put the holes in the side, not the top??

Or are there some there?

Putting them on top would give you a bit better "chimney" effect...


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## jedimasterben (Aug 21, 2011)

I would not have drilled holes in the heatsinks at all - it may not seem like it, but you've actually reduced your overall cooling, as now as air travels through the heatsink it will have less and less flow since it will be escaping out of the sides, so the end of the heatsink won't receive as much cooling as the beginning.


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## robsworld78 (Aug 14, 2014)

Thanks for the heads up on running parallel, least I know what I'm getting into. I'm going to see if I can get one locally first if not I'll take my chances.

The holes were never drilled for air release. At one point I was going to screw the 2 heatsinks together to make one so I drilled those holes to get a bit in there to get to a screw. After drilling the holes I decided not to do that and was upset I drilled them all. So I had one tube with and one tube without holes.

When I used my original 40mm fan I had it on the tube with no holes which helped but when I moved it on the tube with holes it ran much cooler on the first half, the second half did get hotter than if there were no holes. I knew I couldn't rely on a single fan because if it dies this will overheat. So only option is to have a fan on each side which means I need holes to let the air out somewhere so I went ahead and put holes in the other tube as well. I never once thought I would need a fan to cool, if I thought that I would never have gotten this tubing.

All this stuff going wrong for me is actually great, its the best way to learn (maybe not cheapest). My tank for instance, first planted one for me, did it 2 months ago and everything is perfect, I didn't learn a dam thing.


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## robsworld78 (Aug 14, 2014)

The only thing I don't like with this light is lots of it escapes the tank and lights up the living room. The light is at the top of a 6" canopy which helps but it still comes out 10-15ft lighting up the floor.

Would lens be a good idea? I can get 55degree or would that cause spotlighting? The Led's are about 7" apart and the light will sit 2" - 6" above the tank. Tank is 18" wide and 22" deep.

Would that help keep the light in the tank? They would cost $140 so its a tough one.

http://www.ledil.com/node/2/p/10757


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