critique my diy led plan.

[vinnythebat]

this led im planning is for a led light for a mother plant in a 19x19x24 inch room. i will be using cree leds attached to a heatsink. my plane is

15xCREE XT-E Royal Blue LED
5xCREE XP-E Red LED
8xCREE XP-G R5 Cool White LED
2xMean Well ELN-60-48P dimmable driver

I will drive all leds at .700mW this should add up to about 61 watts. do you guys believe this will be an adequate led set up?

 

[trem0lo]

Looks like a good plan!

Have you considered warm whites over cool whites? Cool whites have a huge spike in blue, but you already have that spectrum covered. Warms have a bigger spike over the yellow/green/red spectrums, so they'll fill in the gaps better. But since you're not blooming this is probably not a big deal. And if you don't need dimming, the LPC-35-700 is a cheaper driver.

 

[vinnythebat]

thanks for heads up on controller. do you know of a cheap cree supplier?

 

[trem0lo]

Other than the usual suspects (Mouser, Digikey) no not really. Rapid LED has good prices but not a big selection.

 

[vinnythebat]

thx man, what do you think i should use for flower my flower area in kinda small, its W40"xH30"xD20" i was thinking 160-200w of leds just cand find a good ratio of r,b,w any thoughts?

 

[trem0lo]

That sounds pretty good, I use 5R:2W:1B for my ratio in flower. For a veg lamp we only need red/blue but I'd throw a white in there just in case.

The reasoning is, in flowering we want to cover the peak PAR wavelengths for chlorophyll A&B, which are approximately 425-450nm (blue) and 625-660nm (red). So why the whites? The warm whites contain good amounts of red and some blue while covering green, yellow and orange just in case the plants need it (the jury is still out). So if you have enough of them, an argument can be made for using only 660nm for your reds which is the more efficient wavelength anyway. Sorry I got rambling a bit, but that's the reasoning behind my light design.

 

[trem0lo]

double post sorry!!

 

[T_B_M]

thanks for heads up on controller. do you know of a cheap cree supplier?

Cutter is good. Buy them pre-mounted on MCPCBs. Then attach those to your heat sink with arctic silver thermal adhesive.

Also, from experience, get more red. That is a lot of blue and they won't grow as fast. Once I added more reds and cool whites to my veg setup, they had a way better growth rate. Or just get a couple 24" warm white floros with the red hue to supplement.

 

[PetFlora]

IMO too much B. Plants only need ~ 25% B.

Cree XP-E warm whites/cool white have a good amount of 450-600, so all you would need is a couple 420s + 650 + 660s + 740s

Best to put a couple 420 + 660 + 740 on a separate switch to engage from mid flower on.

 

[vinnythebat]

ok so after a little more research this is the flower light i came up with

75 Osram 660nm 3W Red
30 CREE XP-G Warm White
15 CREE XT-E Royal Blue
9 Mean Well LPC-35-700
this ends up being about 209watts and about 750 dollars without heat sink. would it be cheaper to purchase a retail led light? if not how would i determine the heat sink size? and will lenses increase penetration?

 

[rives]

There are a couple of spreadsheets floating around on the net for calculating your heatsink parameters. I'll get a look and see if I can find a link for one. Yes, I can guarantee you that it would be cheaper to buy a commercial light fixture, but you aren't going to find one that will have the quality LED's that you have selected. I bought my Lumigrow ES330 on sale a couple of years ago for $1000, but haven't seen them that low since. They also come with a warranty, which can be pretty attractive. When I built my fixture, I was surprised at the amount of money and effort that it took to build an enclosure that worked well and protected the components. Yes, lenses will increase your penetration, but will decrease your coverage and will also diminish the light output.

*edit* Here you go. Save the file and change the extension to .xls. All credit goes to SupraSPL. http://www.icmag.com/ic/showpost.php?p=3536569&postcount=42