Building a LED light system for a wardrobe

[Head_Down_Under]

There's a lot of stuff about LEDs, how they compare/cost to other lights etc. but this thread is specifically about constructing a LED system for a wardrobe (because thats what I'm just about to do). I'd like to share what I learn, and hope to get heaps of tips/ideas from other folks out there pursuing similar projects.

Getting Started:

I'm stuck with a wardrobe and little space, so everything is based around that: Footprint about 0.46m x 0.46m and height 1.6m. Although it was already white on the inside I doubt it was titanium oxide so I increased the reflectivity by lining it with alfoil (this will make it a little trickier to photo well).

For a power supply I've chosen a dead desk-top computer's power supply. I havn't checked the voltage out yet but expect it to be between 12 - 20 v, nicely regulated, and capable of providing more than enough power for my needs. As a bonus it comes with a little fan for exhaust or circulation in my wardrobe. The wiring plan is to run a line of LED in series with a voltage drop just a few volts below the power supply's rating, and then put a suitably rated resistor in series with it for current limiting (there's already an energy inefficiency there, any suggestions for more efficient current regulation?). Then I just make more of these little strings, up to the required light output, and add them all up in parallel to the power supply.

I havn't selected a suitable substrate but I'm on the lookout for a bit of cheap veroboard or similar. Later as the plants grow I thought I'd wire up some 'strings' of LEDs and drape them over the plant to ensure light penetrates evenly to all of the leaves, and also because I think it would look very pretty.

Significantly I've decided to make my system hybrid with Fluro during growtime, and possibly hybrid with a redder light source during budding. My reasoning being that a little bit of broader spectrum wont make much difference to power consumption and waste heat generation, but may make a big diference to filling in any much needed gaps in the spectrum (see I'm not a purist here, just looking for a practical solution). Also a bit of compact fluro is cheap and easy to instal, whilst blue LEDs are the more expensive part of an LED system.

I havn't yet worked out the balance and amount of LED red and blue light, and havnt selected a supplier or part (tips welcome here, supplier to Australia). But I've got a nice windyround 20w cfl at 6400K, so I shall use that to start first part of grow. I've yet to work out how much to cut back on blue LEDs to allow for the cfl.

Off to work now, more later and comments most welcome

 

[Getmelifted]

Are LED lights really benefical? This must be somewhat new

 

[Head_Down_Under]

No disrespect Getmelifted:
There's heaps of discussion about whether or not LEDs are beneficial elsewhere on this site. However I hope to keep this thread on topic - discussing how to actually construct a working, practical LED rig.

 

[dr_toker81]

i have seen led grows in pics and other forums.. it seems to get same results as hps and mh and seems to be a bit more expensive though the turnouts are great. i was actually thinking about adding led to my grow before it got taken. i think the led and cfl hybrid will do great! hope u get some pics up so i can check it

 

[SPEARCHUCKER]

Have you thought about the Xitanium 120v conversion drivers as a power source?

Once I can find a good heatsink, Im going to try building one using it to power some Luxeon LEDs.

Heres the link if you want to check them out. Makes LED building alot easier if you dont know much about current.
hxxp://www.luxeonstar.com/led-power-drivers-high-voltage-drivers-c-41_49.php?zenid=mtpukgfu9k5g02vo8cu1bfsmk0

 

[Head_Down_Under]

Spearchucker: thanks for the tip. Luxeonstar drivers look good from the link.

However I already have a power supply from a dead computer so I shall be using that as the cost is zero. There's a range of voltages, and at 24v its rated for 0.5a, giving 24 x 0.5 = 12w which is almost adequate (losses for current limiting resistors need to be taken out of this yet). Else wiring differently there's 12v at 5.5 amp giving 66w, which is more than enough power.

I havn't selected LEDs yet, but assuming 1.6v drop per LED I get 7 LEDs and 1 resistor in series. Assuming 30ma per LED the resistor is (R = V/I) = .8/.03 = 26ohm.
That gives (P=IV) = .03 x 9.2 = .276 watt per string of 7 LED

If I ran the LEDs at 35ma then R = V/I = .8/.035 = 22.8ohm
giving power rating P = IV = .035 x 9.2 = .322 w per string of 7 LEDs.

In this case 62 strings of 7 LEDs will draw 62 x .322 = 20 w
i.e. 62 x 7 = 434 LEDs

Thats more Leds than I care to solder, so I'm looking for higher rated ones - any suggestions anyone?
PS hoping my maths is ok, its late and I'm rusty

 

[Head_Down_Under]

sorry there's a mistake in my maths - should be 11.2v not 9.2 v - too tired, shall fix it later

 

[The Hemp Goddess]

Get rid of the aluminum foil. It has very poor reflective quality. Flat white paint is quite a bit more reflective than foil.

 

[Head_Down_Under]

Good tip thanks Goddess - I never was keen on alfoil as I feel it contributes to hotspots, whilst white is good at difusing the light.
I'm off to the shop now for a can of titanium white paint

 

[Head_Down_Under]

My stuck point now is sourcing high power coloured LEDs. The best I've found after much site trawling are only in the 30-35ma range i.e. way under .1w each, which means I'd need to solder many hundreds just to grow one plant. I've so often heard mention of LEDs ranging in power from .5w up to several watts (unless these were assemblies not sinlge LEDs?) but I cant find them.

Can anybody send links to suppliers of highpowered coloured LEDs? I'm in Australia so they'd have to ship out that far.

 

[SPEARCHUCKER]

Use that powerdriver link I put up Head Down. On the left you can select colored LEDs and such.

 

[Head_Down_Under]

THanks SpearChucker they look good.

I've heard praise for 660nm red now, over 630nm. Do folk out there have experience with both? I'm tempted to use both as a hedge better, but perhaps one wavelength has proven to be better than the other?

 

[SPEARCHUCKER]

I had a graph somewhere HeadDown. Showed the peaks of color most valuable to a plant. 630nm is useful. But 660nm is better used by the plant. So I really wouldnt worry about the 630s to much.
But for blues, since its pretty level across on what they use. Using both Blue and Royal Blue could help.

Ill send you the graph when I find it.

 

[Kupunakane]

Yo Ho fellow light guru's,

I am using six 4 foot grow lights that I love to pieces. They are awsome for the vegging, but I am also running a 90 watt Illuminator tri color LED set that the plants are crazy about.
My babies tend to seriously lean towards where I have placed the Led's. This tells me that I am right on the money with LED's.
Here's my blue and red ratio with the orange colored one's replaced with added blue. The ratio is 8/2 blue - red.
For the flowering I need only toss in my 250 Watt Hps, and every thing will just bust beautifully. Plenty of fat dense bud, and that is a long ways from where I was as far as indoor grows. I was growing, and flowering under just the flouro's, and my buds were very whispy, thin, and didn't produce the THC that I had hoped for, but I have learned that LED's throw the correct spectrum, and generate so little heat that they don't leave a thermal image footprint, and that is some really new techno learning for all of us to start looking deep into this LED business.

smoke in peace
KingKahuuna

 

[Head_Down_Under]

I agree KinKahuuna, the low thermal footprint cant be detected with IR cameras, power consumption low enough to avoid detection, all small enough to use in microgrow set-ups, and with care LEDs can provide the right bits of the spectrum.
I can see that the (at the moment but bound to improve) high LED price has lured manufacturers and customers into insufficient light levels to save on startup costs and this seems to be the cause of most of the poor results and bad reputation that LEDs get.

Being always the tinkerer (and a skinflint to boot) I've been trawling through the literature and so far have arrived at a plan for a set-up that uses about 80w of red 660nm. For the rest of the spectrum I'll start with about 2 x 20w cfl at 6400K (cheap to by, tolerable in terms of waste heat and efficiency). I'm relying on the broader band of the cfl spectrum to fill in some of the missing gaps on the red endof the spectrum besides providing plenty of blue for veg.
If that works ok then my next move would be to add around 12-20w of white LED and pull backon the cfl. I'd be going for white LED instead of blue LED for veg because in essence, a white LED is a blue one with a fluroescent coating that converts some of the blue into a nice smooth curve rising through yellow, orange and dropping down through red. So once again I'd be using the white source to provide the blue and then round out the supply of longer wavelengths too.
For power I'm looking at a computer power supply for voltage regulation, and then I'll just design and make up a current regulator for each line of LED in series that Ihook onto it.
Yes I realise at the moment this just makes me someone whose 'going to do it' but its taking a really long time to get firm info on LED supplies and anyway there's no rush as my seeds don't come for a while yet so I may even end up having to test drive with a little cherry tomato crop.

So right now I'm looking for red 660nm LED between 1w and 5w, sufficient to make a 80w panel and deliverable to Australia. I've pages and pages of spec sheets but just havn't found a supplier yet who fits the bill.

Otherwise if I can find a readymade 80w panel on 660nm alone with an ok price then I'll just settle for that and save a bit of construction time (I put out a search on:
www DOT alibaba DOT com
and heaps of spec sheets and prices are coming in now (ps I think the restriction making it hard for me to give you that link is a crock - what a dumb annoyance)

BTW thanks Spearchucker for your help too,much appreciated

 

[Head_Down_Under]

I hope I'm wrong, but someone please correct me if that's the case but I'm beginning to smell a rat regarding LED power ratings in Commercially assembled panels.
After many days of searching lists of suppliers and manufacturers I just cant get the numbers to add up. A typical price for a 90watt LED lamp is about AUD250, and that would have about 80 1w red at 630nm, and then say 10 blue around 430nm. But the best prices I can find for LEDs cost more than the panels that they'd be put in. For example, Farnell has red 630nm 1.2w LEDs at AUD5.23 so an 80w of these would cost 80 /1.2 x 5.23 = AUD349 !!! and blue LEDs would cost even more, and I can't even find a supplier for fair priced 660nm. These are best prices for LEDs, before I even look at current regulators, veroboard etc.

My plan was to make an 80w panel of red 660nm and supplement it with either cfl, or white LED. But the costs for making my own would just be ridiculous.
So I ask anyone who may be able to help:

1. Has anyone checked the currentflow of their commercial panel to see if it really does run at the rate claimed? i.e. does a 90w panel on 110v power consume 0.82amp, plus a bit for the fan, and a bit more for losses in current regulation (a resister in series with 4 LEDs is going to be a large percentage loss)
2. Is there someother way of describing the power output that manufacturers are using,so that in realityI could make a worthwhile panel with just, say, 50 bucks worth of LEDS (which would really only burn around 11 w)
3. Is there something going on that I just don't get?

Thanks heaps for any useful help

 

[SPEARCHUCKER]

What kind of LEDs have you been looking at? The little 2 prong bubbleball one. Or the Star ones.
I havent seen any really cost that much.

But if you look at the UFO. Thats 90x1watt diodes. With each only putting out 10 or so lumens each. UFOs I seen only push between 900 and 1200 lumens.
You can build your own using the 1watt Luxeon Star LEDs at 40-44 lumens per.

 

[Head_Down_Under]

I looked at quite a few types mostly 1w, but also 3w and 5w ones with heatsinks already installed. Anyway upshot was that according to the spec and price sheets I cant purchase 90w worth of LED for less than the price of a 90w panel of similar spectrum.
Furthermore I've learnt that to run a 90w panel there will be losses for current and voltage regulation (at least 10% - more likely a lot more) and also cooling (my guess is a 5-10w fan?)
So for example, when a UFO panel is advertised at 90w, does that mean 90w of LEDs, or does it mean that the entire assembly consumes 90w.

On my guestimates, a 90w panel using 90 x 1w LEDs would consume 90 x 1w + 15% (regulation) + 10w (fan cooling) = 135w.

and the otherway of looking at it is that if the panel draws a total of 90w then the total LEDs will be doing is 90 - 10 (fan cooling) - 15% (regulation) <> 70w, but the manufacturers say their panels have 90 x 1w

This may look like a load of fuss over nothing, except that I'm trying to get the correct ratings to build a 90w panel, like the UFOs I see advertised on ebay, and I dont know how much power to use. Also, I just cant see how a panel of 90 x 1w LEDs could cost less that just the 90 1w LEDs, before I but all of the other parts.

But finally, and because this was meant to be a fun and profitable project rather than a chore of maths, I've given up at least for the time being. I've purchased a 90w R:B 7:2 Red 660nm Blue 460nm from China. Hopefully it will arrive before I get into bud stage. Also I hope I've got a good product that will bud a few plants successfully. Now I'm off to assemble my wardrobe and germinate a few little fellas...

 

[Head_Down_Under]

I still have plans to construct my own growlight panels but its now a project on the backburner for a while. Based on what I've read to date I'd be looking at Luxeon 1w 660nm - around about 80 - 100 of them for the bud cycle, and then luxeon 6500k white, between 50 - 100 for both cycles.
As far as heat-sinking goes I'd be looking at 3/4" copper pipe as a substrate, making red panels of a long thin shape to place vertically around the plants so the red light can penetrate where the buds grow. For the white panel I'd use a flat plate, more likely aluminium which can be purchased in blocks and plate fairly cheaply as scrap from boat builders, then blow a small computer fan across the back. This would make a white light source above the plants that they could grow towards.
Meanwhile any LED panel builders out there please get in touch I'd like to trade notes.
Cheers and joy

 

[Head_Down_Under]

I still have plans to construct my own growlight panels but its now a project on the backburner for a while. Based on what I've read to date I'd be looking at Luxeon 1w 660nm - around about 80 - 100 of them for the bud cycle, and then luxeon 6500k white, between 50 - 100 for both cycles.
As far as heat-sinking goes I'd be looking at 3/4" copper pipe as a substrate, making red panels of a long thin shape to place vertically around the plants so the red light can penetrate where the buds grow. For the white panel I'd use a flat plate, more likely aluminium which can be purchased in blocks and plate fairly cheaply as scrap from boat builders, then blow a small computer fan across the back. This would make a white light source above the plants that they could grow towards.
Meanwhile any LED panel builders out there please get in touch I'd like to trade notes.
Cheers and joy