LED Mythbusting, KILL A WATT proof

VerdantGreen said:

bassy, i wouldnt worry too much, SX has a lot of knowledge of LED's for sure, but from what i see he also has a fanatical hatred of ALL commercial LED manufacturers who he thinks are just in it for a fast buck. so he thinks all lamps are junk unless you made it yourself.

you wait till you smoke some of that weed, you might be pleasantly surprised. i agree it can be annoying when a product isnt quite what the manufacturer claims, but now you know its a 400w light you can at least judge it accordingly

VG

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Well last grow was only mediocre smoke. Ever since I've been worried it's the light.

Here's current pics 7 days into 12/12 with about 400w of cfl supplemental light in corners. Four plants in 4x4.
https://www.icmag.com/ic/attachment.php?attachmentid=164421&d=1335789301
https://www.icmag.com/ic/attachment.php?attachmentid=164422&d=1335789301
https://www.icmag.com/ic/attachment.php?attachmentid=164423&d=1335789301

VG said ive used these typed of extra light in panels so far:
15% white - i found it caused a bit too much stretch
5% white - not enough stretch - yield suffered
15% green just right


I am wondering what leds you tried and whether the new Cree XPEs would change the outcome. Any thoughts on this?

Bennyweed1 said:

GLH (growledhydro)

Dont know if he is still around but the guy made some great lights. Im glad I got some when I did.

2010 model 120w Spectra

panel 1
Rated:120w
Actual: 171w

View Image

panel 2
Rated: 120w
Actual: 171.5w
View Image

panel 3
Rated: 120w
Actual: 156w
View Image

All these lights are about 2.3yrs old so the power draw as for sure dropped down from when I first got them. They still rock though.

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thanks

I feel like I should chime in with my small bit of electrical knowledge as well as the bit of research I did back in the day when I first started growing and was thinking about LEDs.

So basically, the different electrical energy measurements you can take on an LED are all related. Amperage, voltage, and wattage are each interconnected, since Amperage*Voltage=Wattage. You can switch that equation around however you want to find an answer as long as you have the two other amounts already.

No matter what, the wattage pulled from a kill-a-watt meter is accurate at describing the electrical energy pulled from the entire unit. The unit itself is supplied with 120v, it doesn't matter that the voltage gets dropped to 12v before being used by the LED, if you measure the current draw at the input, that's the input, period. Even if the unit runs on 240v instead of 120v, the current will be nearly the same. 240v is very slightly more efficient than 120v. The only difference will be the amperage, which will be half that of 120v. Any electrical energy used by the transformer stepping down to 12v is part of the process and needs to be taken into account to make a sound judgement on the quality of the unit as well. Cheaper internal parts will put out more heat and more electrical noise and be less efficient than higher quality parts (at least typically they will).

Knowing this, one major thing we need to take into account is the type of LED used. Not all LEDs are as efficient as the next and not only does this vary between the way the LED is manufactured but also is based on the desired wavelength of light. For instance, reds are very hard to manufacture with a high lumen/watt ratio whereas blues are easier and are typically cheaper than red leds.

This brings us to the next part which is the efficiency of the desired wavelength. LEDs have EXTREMELY narrow spectrum bands. They typically range around 20-30nm in length so choosing the right wavelength and mixing wavelengths to achieve a decent spectrum is key.



This is an example of what an LED spectrum looks like. There are 3 LEDs pictured.


As you can see below, the spectral distribution of an HPS is much wider and varied.




This is the plant sensitivity curve:



Basically what you want to do is hit the wavelength at the highest points of the sensitivity curves at your redish orange, yellow, and blue and then using those wavelengths, find an LED that is cost efficient relative to what you want (energy efficieny as well as initial cost need to be taken into consideration).

You would need something that could do a spectral analysis to get the true efficiency of these units so I guess energy efficiency compared with growth at decent conditions is about as good as it gets.

it's called a par/quantum meter, which would be ideal, because then you could compare HPS to CPF to LED with one shot. Unfortunately those are a few hundred $$ each, and the kill a watt is the best alternative to test manufacturer's claims of wattage draw.

It's not the best method of comparing light output between LED's, but it does give some indication as to what's going on in the fixture, is it running at the wattage they say, or do they just say it's X watts because they multiply the number of LED's by the labeled wattage of the chip?

i once read a research paper on many different lamps used in growing.


they found that a lps (lamp that gives off light in the orange spectrum only) (but has the most watts to lumens of all lamps)

outperformed a hps (that performed best after the lps)

IF you added a 100w incandescent bulb with the lps to fill in the missing spectrums of light.

so basically plants only needed a strong source of one color (this case orange) with a bit of the other spectrums to fill in.

this was not a cannabis study though and i forget what plants they used in the study

Phychotron said:

it's called a par/quantum meter, which would be ideal, because then you could compare HPS to CPF to LED with one shot. Unfortunately those are a few hundred $$ each, and the kill a watt is the best alternative to test manufacturer's claims of wattage draw.

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Actually, a quantum meter doesn't do a good job measuring the red range accurately. Having seen Phaeton's on here, and his warning about it, I researched them pretty carefully. Most companies don't emphasize the point in their literature, but if you ask them, they will tell you that their instruments aren't appropriate for measuring light from about 630nm up. Unfortunately, it takes a spectrometer, and they seem to range upwards from $50,000.

Just came across this http://www.osram-os.com/osram_os/EN/News_Center/Spotlights/Products/OSLON-SSL-80-adds-a-touch-of-color.html

Pig Pen said:

SX, you and I are kindred spirits.
Your view on LEDs are spot on in my opinion, both the EE and marketing.

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Thanks, PP, I appreciate it. Everyone comes to the table with a unique and personal body of knowledge to share; the combining of which is what makes communities like this special. I know that in instances where my own experience is lacking, which are not uncommon, someone else is usually there to fill in the pieces of the puzzle.

Pig Pen said:

Some of us have designed far more complicated and cutting edge devices in the "real world job" (as opposed to reading about them). In fact, my first fixture was made using experience I garnered while designing LED surgical lights and preceded even the UFO style that were weak and relatively useless.

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Excellent! Hope it's working well for you.

Phychotron said:

SX, which led fixture do you recommend?

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Thanks Phyco, I usually don't like to recommend particular models, they all have their own pros and cons. I encourage folks to do their own research and make that decision for themselves. "What might be right for you, may not be right for some", as Mr. Drummond would say.

(Yes, I just dropped a Different Strokes reference. Showing my age, eh folks?

I get a bit of carpal tunnel and perhaps some early arthritis in my right hand as well, these days - last time I wrote more than a couple paragraphs, my fingers hurt for two days afterwards. Kinda limits what I want to 'say', oftentimes. Gotta be more careful, these days...body just ain't what it used to be.)

----

That said, I am hoping for some good things from the new Evo v.4 units, though. I believe they've worked out their c/v issues finally, and incorporate the best LEDs (and generally don't overdrive them) of any commercial panel on the market right now. Even with their imbalancing of strings, they still outproduced virtually every other panel out there on a per watt basis, because they got at least two things right - 1) quality of the LEDs, and 2) thermal management. I don't expect an owner to be an expert in every part of their business, as long as they can hire people who are, to do the actual work.

With the drivers functioning properly, perhaps they'll finally have the Trifecta.

Pricing and delivery info should be finalized a bit later this week, according to Gud - fingers crossed.

Might help if they put someone else in charge of providing professional customer service, though - but I don't think it's appropriate to let a bad report or two curtail me from them in general, as unfortunate as that is for those on the receiving end. As long as they can ship a unit that works, hopefully you'll never have to call customer service ever again. (Other's mileage may vary.)

If that was the case, HGL or some of the others out there with bad feedback wouldn't ever have sold any units to people, either.


Cheers,

-SX

nothing like the new buyer's theory of "led's never break." only to find out a power supply or fan or in my case, an entire row of lights. I just had to send my blackstar 500 back after 9 months. The cool part though is that i asked if i could get two 240's instead and they are cool with it.

Plus i theorize that the smaller the fixture is, the better it is at heat management. As long as they keep a low led density. I've seen a bunch of lamps out there where they jam pack as many led's as possible into an area, looking like a heat sink-nightmare. the blackstar 900 seems like it would burn out a lot since it only has 2 more fans than the 500. maybe they upgraded the heat sink, but it still looks like something they threw together to get people who just want to $pend.

another thing that I've noticed is that the light-canopy density seems to make a difference. In general, one fixture with X watts is not as good as 2 fixtures with X/2 watts because you can spread it out and get better coverage. The next step is for manufactures to find that ideal led-density. I liked the concept of those evo bar's with their idea of spreading the light out, and then i noticed that it's just a large heat sink.

I was considering doing something like that if i ever made one, just get some aluminum rails and space out the led's as much as possible. For now just went with the advanced diamond series 400w because it's long and skinny compared to many fixtures. I figure 2 will fill out my 4x4 tent

I often wonder how good those fans are in led fixtures. Decent static pressure would be needed to pull through those little vents, and cheap axials don't have much.

Phychotron said:

nothing like the new buyer's theory of "led's never break." only to find out a power supply or fan or in my case, an entire row of lights. I just had to send my blackstar 500 back after 9 months. The cool part though is that i asked if i could get two 240's instead and they are cool with it.

Plus i theorize that the smaller the fixture is, the better it is at heat management. As long as they keep a low led density. I've seen a bunch of lamps out there where they jam pack as many led's as possible into an area, looking like a heat sink-nightmare. the blackstar 900 seems like it would burn out a lot since it only has 2 more fans than the 500. maybe they upgraded the heat sink, but it still looks like something they threw together to get people who just want to $pend.

another thing that I've noticed is that the light-canopy density seems to make a difference. In general, one fixture with X watts is not as good as 2 fixtures with X/2 watts because you can spread it out and get better coverage. The next step is for manufactures to find that ideal led-density. I liked the concept of those evo bar's with their idea of spreading the light out, and then i noticed that it's just a large heat sink.

I was considering doing something like that if i ever made one, just get some aluminum rails and space out the led's as much as possible. For now just went with the advanced diamond series 400w because it's long and skinny compared to many fixtures. I figure 2 will fill out my 4x4 tent

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there seems to be a movement towards bar typed arrays, several manufacturers are now offering them...

welthink was the first i think, but now HGL is in the game, Lumigrow has the Lumibar and TI the Smartbar, just name some off the top of my head...

the aluminum heat sinks (like what's on the EVO's) are definitely a step up from the fans (because the fans do and will fail).

btw, what are the dimensions of your advanced DS 400?

the 400 is 8.5"x36" Funny cause I had to email them before I bought it to make sure. They said they were working on updating their site, guess they haven't got around to it.

it also runs cooler than the blackstars do. When i cracked open the BS500 to test the power supply it just had a thin sheet of aluminum with the fans blowing on it. Not sure what the diamond series is packing for a heat sink, but i like the larger, quieter fans on it.

Just a reminder that the TI Smartbar is water cooled, thus has no external heat sink or fan. It has also been produced unchanged since 2008, so it is getting a bit long in the tooth in regards to LED technology.

i looked up all those mentioned, the smart bar was looking kinda pimped with it's water cooling and all, but i would hate dealing with the hassle.

It seems like the ideal LED has only a big heat sink, like the evo bar style, but that's an investment that you need to make in aluminum. Of course you could always add some fans to the heat sink if need be, but ideally the aluminum should do the work. I was watching a few videos on youtube about making some aquarium panels, they were using krazy glue or thermal epoxy to mount the led's right to the block.

When i get a broken fixture or two laying around i'll probably invest in some aluminum bars and start playing around. I was also considering using old CPU heat sink's and making smaller fixtures. a 10" x 36" x 2.8" heat sink is 165 plus shipping from one site. It's not that much $ for a fixture that big, just need to figure out the ideal layout for optimal heat dispersion.

However, since i'm all about spacing, i was considering making a bunch of thin rails, using 1.8" wide heat sink, @ 68 cents per inch it's 24.50 for a 36" long piece. Mount the led's singe file with alternating patterns between the different rails, as to space the colors out. the bars would need to be numbered to keep them in the right order, but i think about 1 rail per foot would be good. i'd probably get them to be longer, like 46" to fit the 4' tent.

Psychotron, definitely check eBay for heatsinks, you should be able to save a little money there. When I build, I attach them directly to a very thin thermal pad with arctic silver epoxy. Of course this depends on the type of led you use but it's a very good way to go for effective thermal transfer.

Also those aquarium light tutorials are great. They are accomplishing a very similar goal as us, just with different wavelengths.

Phychotron said:

the 400 is 8.5"x36" Funny cause I had to email them before I bought it to make sure. They said they were working on updating their site, guess they haven't got around to it.

it also runs cooler than the blackstars do. When i cracked open the BS500 to test the power supply it just had a thin sheet of aluminum with the fans blowing on it. Not sure what the diamond series is packing for a heat sink, but i like the larger, quieter fans on it.

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thanks for the dimensions...

Phychotron said:

i looked up all those mentioned, the smart bar was looking kinda pimped with it's water cooling and all, but i would hate dealing with the hassle.

It seems like the ideal LED has only a big heat sink, like the evo bar style, but that's an investment that you need to make in aluminum. Of course you could always add some fans to the heat sink if need be, but ideally the aluminum should do the work. I was watching a few videos on youtube about making some aquarium panels, they were using krazy glue or thermal epoxy to mount the led's right to the block.

When i get a broken fixture or two laying around i'll probably invest in some aluminum bars and start playing around. I was also considering using old CPU heat sink's and making smaller fixtures. a 10" x 36" x 2.8" heat sink is 165 plus shipping from one site. It's not that much $ for a fixture that big, just need to figure out the ideal layout for optimal heat dispersion.

However, since i'm all about spacing, i was considering making a bunch of thin rails, using 1.8" wide heat sink, @ 68 cents per inch it's 24.50 for a 36" long piece. Mount the led's singe file with alternating patterns between the different rails, as to space the colors out. the bars would need to be numbered to keep them in the right order, but i think about 1 rail per foot would be good. i'd probably get them to be longer, like 46" to fit the 4' tent.

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where are those? i'd like to check those out...

i just did a quick google search for aluminum heat sinks and came to this site.

http://www.heatsinkusa.com/1-813-wide-extruded-aluminum-heatsink/

I saw some sites the other day that sold them in 8' lengths, but this place is cool enough to go by the inch.

oh, and the diamond series does have a finned heat sink inside.

would sombody get a bright ass led off a downed ufo and reverse engineer it already,damn, people .......