Ultimate LED guide

[allactiondan]

Would a 5.886x12 inch heatsink be enough to cool 20 XP-E Cree royal blues and 10 XP-G neutral whites, or should I step up to the 7.280x12 inch?

The fixture will be run at about 1000ma, and cooled with a 120mm fan moving 47 cfm. LEDs will be in 2 very tight 15 LED clusters - Here are the C/W ratings of the heatsinks acording to heatsink USA.

5.886x3" =1.75 C/W

7.280X3"=1.30 C/W

 

I have found a few calculators online to figure out the capacity of the heatsinks, but my math skills are lacking and I don't know how to take the active cooling into account.

 

Is there even a point to running the numbers, or are heatsinks this size tried and tested?

Edited March 29, 2011 by allactiondan

[evilc66]

A heatsink that size will work, but it is going to be relying on the fan to keep everything cool.

[allactiondan]

A heatsink that size will work, but it is going to be relying on the fan to keep everything cool.

 

 

ok, thanks.

[Paleoreef103]

OK. I'm going to be upgrading to a 40 breeder when I move into a new house in August. Obviously, I want to run LEDs as the main lighting of the new tank. My plan is to run 45 LEDs on Nanocustoms 700 drivers (the trio when it comes out). I plan on running them about 12" off the water with 60 degree optics. I plan on using two 5.25"X32" heat sinks for cooling and a couple of 120mm fans for cooling. My questions:

1) I have two plans for arranging the LEDs. One is to arrange 7 smaller arrays (4 on one heat sink, 3 on the other) of 2 NW, 3 RB, and 1 CB each. (yes only 42 this way) I feel like I would get good spectral completeness and good color blending this way, but I worry about spotlighting. The second would be to make 15 smaller arrays of 1:2 NW:RB or 1:1:1 NW:RB:CB like AI fixtures, and arrange eight on one HS and 7 on the other (with a small gap for an overflow on one side). What do you guys think?

2) Would I benefit from running 2 X29W T5s between the two heat sinks? I was thinking running a purple bulbs and fiddling with the other bulb to maximize coral color. I know it's not necessary, but I think it would be beneficial.

[Dcson]

Hello everyone ...

I'm new to the forum and am developing my DIY LED lamp ...

I wonder if anyone has a circuit design to turn the LEDs gradually, mimicking the sunrise and sunset, for example:

League in 20 minutes

Hold for 8 hours

Shut in 20 minutes

[evilc66]

OK. I'm going to be upgrading to a 40 breeder when I move into a new house in August. Obviously, I want to run LEDs as the main lighting of the new tank. My plan is to run 45 LEDs on Nanocustoms 700 drivers (the trio when it comes out). I plan on running them about 12" off the water with 60 degree optics. I plan on using two 5.25"X32" heat sinks for cooling and a couple of 120mm fans for cooling. My questions:

1) I have two plans for arranging the LEDs. One is to arrange 7 smaller arrays (4 on one heat sink, 3 on the other) of 2 NW, 3 RB, and 1 CB each. (yes only 42 this way) I feel like I would get good spectral completeness and good color blending this way, but I worry about spotlighting. The second would be to make 15 smaller arrays of 1:2 NW:RB or 1:1:1 NW:RB:CB like AI fixtures, and arrange eight on one HS and 7 on the other (with a small gap for an overflow on one side). What do you guys think?

2) Would I benefit from running 2 X29W T5s between the two heat sinks? I was thinking running a purple bulbs and fiddling with the other bulb to maximize coral color. I know it's not necessary, but I think it would be beneficial.

 

1) Clustering will always result in spotlighting to some extent. Obviously, if you run without optics, then the effect is minimized. The tighter the optic used, the more noticeable it will be. Some planning will help minimize it, with correct spacing based on the lens used.

 

I think keeping the clusters slightly larger would be better, so that each cluster has the same count of each LED color. It will help to make the color more uniform across the tank. Smaller clusters will reduce spotlighting, but will create uneven color seeing as you are looking to run multiple colors, some of which you don't want to use all the time in every cluster.

 

2) Benefit? Depends on what you consider a benefit. At the very least, you have more flexibility with overall tank color and color rendering. You are adding in another heat source, and a yearly consumable. I think you will be surprised by the color rendering of just the LED setup that you are planning.

 

Hello everyone ...

I'm new to the forum and am developing my DIY LED lamp ...

I wonder if anyone has a circuit design to turn the LEDs gradually, mimicking the sunrise and sunset, for example:

League in 20 minutes

Hold for 8 hours

Shut in 20 minutes

Lot's of people do this. From the multitude of 0-10v compatible reef controllers, to DIY controller solutions, there are choices for everyone.

[Paleoreef103]

1) Clustering will always result in spotlighting to some extent. Obviously, if you run without optics, then the effect is minimized. The tighter the optic used, the more noticeable it will be. Some planning will help minimize it, with correct spacing based on the lens used.

 

I think keeping the clusters slightly larger would be better, so that each cluster has the same count of each LED color. It will help to make the color more uniform across the tank. Smaller clusters will reduce spotlighting, but will create uneven color seeing as you are looking to run multiple colors, some of which you don't want to use all the time in every cluster.

 

2) Benefit? Depends on what you consider a benefit. At the very least, you have more flexibility with overall tank color and color rendering. You are adding in another heat source, and a yearly consumable. I think you will be surprised by the color rendering of just the LED setup that you are planning.

Thanks Evil! If I could pick your brain for just a few more moments... My plan is to run an SPS dominated reef, so I am hoping for at least 200 PAR at the sand bed. I was hoping that keeping the emitters 12" off the water and using 60 degree optics would help keep the the spotlighting down to a reasonable level while the clustering is for color blending. Do I need optics with 42 Crees running at 700 mA if I drop the height to about 8" ? Would 80 degree optics be more reasonable ? Would the T5s help with light uniformity? I am a little bit concerned about the lack of light below 430 nm so I figured T5s would help.

[evilc66]

To hit those PAR numbers, you are going to need 60 degree optics. 4" difference in mounting height won't account for enough of a change to not use optics.

 

T5's won't really help with uniformity, as it's just another light source. The LEDs will still create different brightness areas.

 

I wouldn't be too concerned about missing light below 430nm. You are still hitting your photosynthetic peak at 450nm.

[Paleoreef103]

To hit those PAR numbers, you are going to need 60 degree optics. 4" difference in mounting height won't account for enough of a change to not use optics.

 

T5's won't really help with uniformity, as it's just another light source. The LEDs will still create different brightness areas.

 

I wouldn't be too concerned about missing light below 430nm. You are still hitting your photosynthetic peak at 450nm.

Thanks again! One last question. How would you personally light a 40 breeder? I know you have your breeder with PAR38 bulbs which is kind of what the 6 LED arrays would giving me, but I think I'd rather have a fixture than track lighting on the basis of my wife would rather it have.

[evilc66]

Color separation has never really bothered me, so I'd probably use a more traditional grid array in a 12x3 pattern. That's just me though. If I were to try a cluster based setup, I'd probably base it around Bridgelux N803's though.

[Svirdulys]

Hi Evil,

I've read most of the topic from the begining and found a few similar posts about what I needed.

But still, I'd like to hear your thoughts on my project, because its a little different from the ones I've read.

The tank is 78x24x24 (200x60x60cm) (i plan to hang my leds 3.15" from the water. total height between leds and sand is 24 inches) I want to get to as close as 250w mh level setup. I know I will have to use 40 degree optics for 24 deep tank.

Next, I want to get more to 20000K look. I am planing to use 2 to 1 (royal blue xr-e to cool white xp-g r5). I'm planing to get 6 rows of 28 (I want to leave ~10" space in the middle). The spacing between leds are 2.36" and between rows 3.15". I know I need to get to as close as to 2" between leds, but the problem is that my cool white rows have already been made for a different project and I have no chance to move them. But I can adjust my RB rows (if you think that spacing is a little too wide). To get everything more even I have no problem on putting more whites towards the middle (if needed).

Also, I've been running 14 cool whites on ELN-60-48D (dimmed to 900mA) with no problems (rapidled has on the description: "runs ~8-14 LEDs"). That's why I want my rows of 28 (2 drivers per row). Do you still think that this might be a problem and I should go with 13? And, what current should I be running for whites and for royal blues to get the most perfect PAR readings?

Look at my drawings. Tell me what you think. I need it to be perfect before I start, because its not a cheap thing

Thanks for all your help

[evilc66]

You should be good with that setup. Don't worry about the spacing issue. You may just have to raise the fixture slightly to reduce any spotlighting effect in the tank.

 

As for the drivers, you can run up to 14 XP-Gs on a single ELN-60-48, but 14 XP-E's is really pushing it. They don't have as low of a forward voltage as the XP-Gs, and will go over the voltage limit on the driver. 13 is borderline.

 

Obviously, more current equals more PAR. You can play with current and lens angle to get your desired PAR values.

[TheWAND]

Color separation has never really bothered me, so I'd probably use a more traditional grid array in a 12x3 pattern. That's just me though. If I were to try a cluster based setup, I'd probably base it around Bridgelux N803's though.

I've been looking for these online, but can't seem to find any sources. Where would I find these LEDs? Would this work?

 

http://www.mouser.com/molexhelieon/?utm_so...CFQImbAod-hwWsA

Edited March 31, 2011 by TheWAND

[Svirdulys]

Thanks again. I was really concerned about the spacing issue. Now I'm fine

What is the optimum height from the water?

And that's it? What do you think about 2:1 rb to cw? Won't be too blue? I guess I could raise xp-g's if wanted to lower K's, correct?

[bmhair03]

Wow thanks to everyone thank added info to this thread. I had to join the forum to say thanks for all the help I got from here. I do have 2 questions .

I think I read that heat sink temps up to 140' where ok? Mine are around 90. Colder better right?Obviously .

I just finished a DYI setup .Heat sink is 4.25' X 24"

24 cree xp-e's running on 2 en-60-48p" just read what (evilc66) wrote about not running 14 on each.

I luckily did a 13 11 slit . At a 750ma output on the 13 xp-e string does that help? Or should I go lower? or change over to 12 12 split. If 12 12, would adding a NW in the center be any better to just another CW.

My heat sink is 20"off the sand should I expect ok PAR when ran at 100% of dimming? no PAR meter. Or lenses.

Ok 2+ questions !

Thanks again.

[evilc66]

I've been looking for these online, but can't seem to find any sources. Where would I find these LEDs? Would this work?

 

http://www.mouser.com/molexhelieon/?utm_so...CFQImbAod-hwWsA

The LEDs are Bridgelux. The Helion product was a colaboration between Molex (housing and connections), Bridgelux (LED), and Ledil (reflector).

 

Thanks again. I was really concerned about the spacing issue. Now I'm fine

What is the optimum height from the water?

And that's it? What do you think about 2:1 rb to cw? Won't be too blue? I guess I could raise xp-g's if wanted to lower K's, correct?

I'd probably start around 6-8" off the water, but make the height easily adjustable so yuo can fine tune it.

 

2:1 should get you a pretty good 20K color temp as a base. Your drivers are dimmable, so you will be able to adjust it to your heart's content.

 

Wow thanks to everyone thank added info to this thread. I had to join the forum to say thanks for all the help I got from here. I do have 2 questions .

I think I read that heat sink temps up to 140' where ok? Mine are around 90. Colder better right?Obviously .

I just finished a DYI setup .Heat sink is 4.25' X 24"

24 cree xp-e's running on 2 en-60-48p" just read what (evilc66) wrote about not running 14 on each.

I luckily did a 13 11 slit . At a 750ma output on the 13 xp-e string does that help? Or should I go lower? or change over to 12 12 split.

The lower current does help with lowering the forward voltage slightly, but you are safe for now. There shouldn't be a need to reconfigure things unless you start to see problems.

 

If 12 12, would adding a NW in the center be any better to just another CW.

 

You'll never notice it. If you want more red spectra out of the LEDs, change all the cool whites to neutrals. That will give you the biggest change. One LED with a 2000K difference is going to get lost.

 

My heat sink is 20"off the sand should I expect ok PAR when ran at 100% of dimming? no PAR meter. Or lenses.

Ok 2+ questions !

Thanks again.

It could be fine, but it's all dependant on what you want those PAR values to be. For a mixed tank, it could be just fine. For an sps heavy tank, more current and/or optics could be required to increase the output.

[bmhair03]

Thanks for the reply.My tank is mostly LPS but have a few SPS at the top probably 8-10" from the LEDS.

Could I bump up my output to 900ma and be OK or is that asking for trouble?

Thanks

[evilc66]

You have dimmable drivers. Try it. If you get a negative reaction, change it back. I'd raise the intensity slowly though (over a week or two).

[bmhair03]

I think I'll finish off this accumulation and see where I'm at. I went with 3 pieces of window screen and plan on removing one every 5-7 days. It made it easier then writing a couple different programs to do both accumulation and sunrise -sunset over a period of time. .Thanks again for the help.

[TripleToe]

For those who are interested, I posted my thoughts on my new Nano Customs 5.6 CREE XRE LED retrofit kit here. Sorry for the crosspost but I wasn't sure which thread to post it in

[evilc66]

Thanks for the review TripleToe

[JChap]

Evil,

I've had my LEDs up and running for almost two weeks now and I've noticed the tank temp goes up into the 81-82 degree mark after being on all day. What do you recommend I do? I current have two of the silenx fans in lieu of the original fans. Also, I have the nanotuners heat sink with 26 cree LEDs.

 

Thanks,

Justin

[evilc66]

Sounds like you need more airflow. The heat isn't allowed to escape the hood fast enough, and warms the water as a result. It's probably also increasing the temperature of the LEDs too. SilenX fans are nice for noise (or lack thereof), but they don't flow that well. On our 3.6 and 4.6 kits, they work ok, but with the higher wattage from a large Cree array, it's not enough. Try looking for some Vantec Stealth fans. Quiet, but better flow than the SilenX fans.

[JChap]

Just ordered, thanks a lot.

[dubbly]

Humm.. I have been reading this thread and just ordered the 5.6 nanocoustoms setup. Is there currently any good way to add 2-3 violet LEDs to the setup? Either by replaceing some of the royal blue leds or adding 3 additional LEDs and a power supply?

 

Ben