1512W LED Perpetual Medical Harvest (Aeroponics)

[SirSmokalot]

Update Photos, 11-22-09:

aww look how cute you are behind that giant high five your holdin. props on the size!
take note everyone. stems seem strong..... holding some serious loads there.

ledgirl you lift weights? that monster looks heavy!
sir

 

[b00m]

That's some serious fucking buds right there, well done LEDGirl. Patiently waiting to see the other LED grows crank out the buds.
Happy Gardening All.
Peace.

 

[LEDGirl]

Bikini shot next time

and is that bleaching up the tops or something similar?? i am genuinely interested in these leds cant wait for Benji's gorw

Hmm, bikini shot huh? We'll have to think on that one lol. Yes, this plant was a bit more sensitive to bleaching, which is why the very tops look very white. Then again, I also like to keep the lights close lol.

 

[LEDGirl]

Isn't PAR typically measured as PPFD?

Yes lol, but you asked for PAR watts first I'll supply the PPFD numbers instead

Better yet, what is the PPFD?

That depends on where you're measuring. The PPFD rating at 6" from your canopy is 116 micromoles per square meter, and at 12" it is 40 micromoles.

The 318W is 351 micromoles at 6", and 117 at 12". This data will be listed on my site VERY soon.

 

[nnep]

LED's put out very little heat, so my 1512W room doesn't go past 90 degrees (usually around 85). Also, 1512W isn't a huge power bill. Not sure if I misunderstood what you were saying or not, but thought I'd throw that out there. If you did the same thing with 400W HPS lights, you'd certainly have the issues you described, so maybe that's what you meant?

Anyhow, lumens are a measurement of brightness for humans. A lot of people have the misconception that a HPS is better for flowering than a MH because it has more lumens, but in all reality the MH has more PAR watts. Either way though, a 400W HID only puts out from 120-140 PAR watts...

I meant the equivalent setup in HIDs, yeah. I probably could have made that clearer

It appears i was misinformed about lumens.

 

[SnozzleBerry]

I've heard a lot of people talking about lumens for some strange reason. When I was at the hydro store talking about the CMH bulb I'd just purchased, I mentioned wattage and had a store rep try to tell me that lumens were more important than wattage. I asked her why that would be when lumens were a measure of light vis a vis the human eye that doesn't tell you much for growing and wattage is a measure of energy usage that should give you a good idea on what your lighting can do. She just kinda stammered and said, yea, I'd heard something like that...

 

[Apache123]

Hello LedGirl! And thank you for your expertise. I am gearing up for my first grow. I have a small 3'x3' closet that I will be growing in. What is the recommended LED light for this size? Will I need air movers to keep the room cool enough? Thank you in advace for any help provided.

Cheers,

Bee Keepers Friend™

 

[LJB]

I've heard a lot of people talking about lumens for some strange reason. When I was at the hydro store talking about the CMH bulb I'd just purchased, I mentioned wattage and had a store rep try to tell me that lumens were more important than wattage. I asked her why that would be when lumens were a measure of light vis a vis the human eye that doesn't tell you much for growing and wattage is a measure of energy usage that should give you a good idea on what your lighting can do. She just kinda stammered and said, yea, I'd heard something like that...

Same is true for any type of retail store. They are not necessarily owned and staffed by experts in the items being sold.

Plants react to photons. Which is, quite frankly, why I don't care about Par watt information. However I also know that the photon data is not easy to come by. There are people working on a quantum yield curve for cannabis.

Good on LED-girl for providing the PPFD and nanometer data.

 

[LEDGirl]

Hello LedGirl! And thank you for your expertise. I am gearing up for my first grow. I have a small 3'x3' closet that I will be growing in. What is the recommended LED light for this size? Will I need air movers to keep the room cool enough? Thank you in advace for any help provided./QUOTE]

A 3' x 3' area would need 2 x 126W, since a single 126W only covers 2' x 3'. If it's a closet, I don't believe you would need any type of ventilation to keep the room cool. Air movers are always recommended though, as they help to create thicker, stronger plants

 

[LEDGirl]

By the way everyone, our NEW web site should be ONLINE by tonight! It will give you the PPFD ratings on all our lights, as well as a plethora of other information so you can understand what PPFD is and how it relates to plant growth. Anyhow, I've tried to design the new site around answering nearly every question I've been asked about our units. Still working on a FAQ, but there is a lot more info coming than what I've had online up until now.

 

[sx646522]

Looking forward to the new site! Soon you can just link to the FAQ section when someone asks you a question you've already answered for the nth time...

The (126W) PPFD rating at 6" from your canopy is 116 micromoles per square meter, and at 12" it is 40 micromoles.

The 318W is 351 micromoles at 6", and 117 at 12". This data will be listed on my site VERY soon.

A regular HID light loses intensity at 1/r^2, i.e. 75% loss for each doubling of the distance from the fixture.

Does this mean that the LED with a 60 deg. angle only drops to 1/3 (66.7% reduction) at twice the originally measured distance?

-SX

 

[LEDGirl]

From what I can see, the light drops 66% (2/3) from 6" to 12", and another 45-50% when you go from 12" to 18".

 

[Nitrain]

I like the lights may not work for my setup but kool technology!!

 

[dongle69]

From what I can see, the light drops 66% (2/3) from 6" to 12", and another 45-50% when you go from 12" to 18".

These lights don't follow the inverse square law?
Is it because they are not considered a point source light?

 

[LEDGirl]

These lights don't follow the inverse square law?
Is it because they are not considered a point source light?

Data is data is data is data. I just report it. The light read-outs are what they are, performed on professional testing machines in China. The results are consistent with every one of our models. That's really all I can tell you in regards to your question.

 

[StealthSniper]

LED, very impressive results. I have been through your website, and just to clarify, a 318W Penetrator has a coverage area of 2′ x 4′ at 12″ above the canopy? This means that two 318's are required in order to cover the same area as a 1000W HID? This would equal 636W plus the cooling fans.

Am I reading this right?

 

[djam]

looks great , im very interested in leds for growing

 

[LEDGirl]

LED, very impressive results. I have been through your website, and just to clarify, a 318W Penetrator has a coverage area of 2′ x 4′ at 12″ above the canopy? This means that two 318's are required in order to cover the same area as a 1000W HID? This would equal 636W plus the cooling fans.

Am I reading this right?

Yes, while LED lighting is much more efficient watt for watt at growing plants, it still requires close to the same amount of wattage as a HID in order to cover the same amount of area. Respectable gardeners use a 1000W HID in an area of 4' x 4' or smaller, although it can be used to light a 8' x 8' area according to most MFR's. So while it takes 2 x 318W to cover 4' x 4', you will get far more production out of that area than you will your 1000W HID. As per the power consumption, the 318W uses 318W including fans, and it includes 318pcs 1W LED's. We have put our units on a power meter and they draw the exact wattage of all the LED's combined.

 

[sx646522]

These lights don't follow the inverse square law?
Is it because they are not considered a point source light?

I believe I've found an answer to my satisfaction. My physics is a bit rusty, but from what I can see:

• A LED is a pseudo point source close to the lens, but mimics a true point source light farther out
• The luminous intensity vs. a point source at the same distance is higher by a factor depending on the lens angle. A point source spreads light evenly over the area of a 360 degree sphere; the lens will direct it into a smaller area based on the spherical cap, like so:

http://mathforum.org/dr.math/faq/formulas/faq.sphere.html
http://mathworld.wolfram.com/SphericalCap.html
http://www.ayton.id.au/gary/Science/Ma_mens.htm

The (initial) difference in intensity at any given distance is the ratio of the spherical cap area for any given angle (60, 120, etc.) vs. the area of an entire sphere, based on the radius.

You can calculate a rough output like so:

http://www2.whidbey.net/opto/LEDFAQ/The%20LED%20FAQ%20Pages.html (see Q#23)

http://members.misty.com/don/led.html#lc (bottom of page)


Based on that, one can also infer that for each LED, a 60 degree lens has ~4x the intensity of a 120 degree lens at the same distance, and ~2.25x the intensity of a 90 degree lens, for any given radius r from the lens.

That's one reason why the HGL units appear to perform much better than the UFO-style at the recommended height - you'll cover a smaller area, but at much higher concentrations, directly under the light.

From what I understand, at greater distances the inverse square law still proves largely accurate for LEDs:

http://en.wikipedia.org/wiki/Inverse-square_law
http://hyperphysics.phy-astr.gsu.edu/HBASE/forces/isq.html#c4

You're simply starting out with a higher luminous flux based on the initial angle as per the above, and dropping it ~ 1/r^2 from there.

And - since the lamp technically has 126 individual sources of light in six clusters of 21 (not just one), as you get farther away from the lamp, you'll get additional cross-coverage from adjacent lights, so the drop-off in distance is somewhat mitigated by additional coverage from more LEDs.

In practice, mapping out the actual intensity on a ~3" x 3" grid at various heights based on the actual readings is much more practical in any event, and will give one a better idea of coverage also.
------
If anyone with a more recent background in physics wants to clarify, add to, or correct this - please feel free! It's been a few decades for me, at least... :

Cheers,

-SX

 

[LEDGirl]

Seriously, I love having you around to fill in the gaps SX, and I still have no clue who you are lol! Thank you by the way! Your knowledge is much appreciated.

Here's a link to our new site if you wanted to see it, which will be completely up and running tomorrow: http://www.hydrogrowled.com