DIY LED REVOLUTION/EVOLUTION! INTRODUCING MEvo

sup jubiare, im doing a legal grow in a closet. i have a buddy who knows a good amount about electrical and i was going to ask him to build me a 1000w led grow light or lights. i have about 1g to spend so money really isnt an issue. i was thinking of building 2 seperate grow lights 4 feet each, about 500w each. my space is 8 feet wide by 1.5 feet deep and about 7 feet tall. how many 3w led chips do you think i should put on a panel that would be 4 feet x 1.5 ft? What kind of ballasts or other parts would i need to run a light that powerful??? please answer me back im serious about doing this and building a couple badass grow lights and be able to share my blueprints with all that want to do the same. hit me back. one love

Hi greendream, as from knna, we have to install a minimun of 25W/sq ft in order to get good results. It yield aprox as a 40W/sq ft of high wattage HPSs. If you want to match the yielding potential of a setup of, for example, 75W/sq ft of HPS, you must use at least 40W/sq ft of LEDs. And that is expensive right now. I am talking here about top notch brands, and bins, when possible. It all depends what your target is

I don't know exactly how many leds you would put on your 4 feet arrays ... I'd say do not space them closer than 1" apart. If you really want to maximize the space, use side lighting instead of packing all the diodes closer together! It all depends what your target is

You won't need any Ballast with leds

Let me know how you wanna go about with your ambitious project

Jubiare
I have been reading about your own DIY LED and i fancy trying it myself, i have a few questions that i need answering and im hoping you can help.
How do you know what LED driver you need? They have different voltage outputs and different wattage outputs, lets say i have 3x 15 led clusters and they are 3w leds. Can i put all 3 in parallel or do they have to go in series? Or do i need a seperate driver for each cluster?
As with heat could you not extend your cable from your driver to your led light so that the driver does not heat up your heat sink?

Many thanx

you need to decide what you want to drive the leds at, first.

Let's say you want dimmable drivers, that way you can regulate the different phases of the grow, even have a more vegging light for vegging etc. I don't do that, as my design is different long heatsink arrays ... ideally you want to dim, but it'll cost you more money too.

Let's say you want to drive your reds at 500Ma. You can drive them at 630/680/700 too, but you sacrifice some efficiency for heat ... it will cost you less drivin the leds harder. (less emitters to buy)

let's say you chose a driver that is 35w output DC 12v - 70v. What you have to care for is Voltage, not watts: you want to drive as many leds as you want between 12 and 70v. let's say that the led is 2.2v each at 500Ma (you get those figures from datasheets): so you would do 2.2 x 20 (for example) = 44v, so you are fine as that number is in between 12v and 70v. You never wanna go over 70v, you follow? Actually is best to never go over 68v, so the driver won't be overloaded (more heat etc).

Yes you can have the drivers outside of your grow space or wherever, mind it would be good to have them dissipating heat on a heatsink. It's your choice whether you want to mount them on the heatsink

You'll have to chose a design and calculate heatsink dissipating area, THAT IS VERY IMPORTANT. You have some info on that by reading previous pages. You'have to decide if you want active cooling or solely passive cooling

And anyway if you got the patience and the passion, have a look at
How to build your DIY LED array


that's a very good solid start, it might take you a second read to digest everything you need. Best to take notes of important passages

Good luck

Oh i see well that makes sense about not worrying about the watts, why would you not go over 70v on a led driver? is it because they produce more heat once they are bigger? As with the driver i would still put it on a heat sink just on its own one so as to allow maximum efficeintcy for the led heat sink. I thought if the leds were in series if one went out they would all stop working as the current would not be able to pass through?

I believe he was saying that if you have a 12v-70v driver don't exceed the higher number - the maximum output (in this case it's 70v). If you had a 70-300v driver then don't go above 300 - or to be safe and not have it run super hot don't run it over ~250v. But you would be able to go above 70 in this latter case - actually you wouldn't want to run less than 70 at any time.

thanks for the response jubiare. so i figured out i have 12 square feet total and 40w per square foot is 480 watts for my entire grow. i did some math and im going to make 2 lights, both would have 4 rows of (40) 3w diodes = 480 watts ea!! so 960w total other then the diodes and panel what kind of parts would i need to run a light this strong? drivers etc. thanks j, much love

Originally Posted by staf82

oh i see well that makes sense about not worrying about the watts, why would you not go over 70v on a led driver? Is it because they produce more heat once they are bigger? As with the driver i would still put it on a heat sink just on its own one so as to allow maximum efficeintcy for the led heat sink. I thought if the leds were in series if one went out they would all stop working as the current would not be able to pass through?

if a driver is 70v max, you don't want to go over it, actually go just a step before the max allowed, OR ANYWHERE IN BETWEEN THE MIN AND THE MAX