LED lumens - sanity check?!

[lenngray]

On eBay, just now, I read through a listing titled:

"50*3W 90W UFO Hydro LED Grow Light Quad-band 71:1 for Flowering"

It explains that it uses 3W LEDs, at an actual power of 90 Watts,
with the detail: "Bridgelux RED 35 Blue 5 Orange 5 White 5 LED".

I've believed that Bridgelux sold pretty good stuff, so when the
text _explicitly_ listed the light's specs as 2700 lumens, I was
disillusioned. That's only 30 lumens per actual watt !!

My 400W HPS generates 55,000 (!) lumens of admittedly yellow light,
but even granting a 4X advantage for an ideal PAR spectrum (which
I highly doubt) that'd put this light at an actual 1/5 of my HPS.

Where are the beyond-100 lumens-per-watt stats of red and blue
light that everyone alludes to ?

I _do_ also run an old Taiwanese 300W LED light, so I'm asking as
a potential customer for some new lights, too, inspired by recent
hype saying "hey, they're really already better than HPS".

Let's have actual _numbers_ for LED lumens -- something that
can be tested and verified. Let it be one number for each band
if necessary. We can handle the truth. Stop filtering out the
complexity assuming our brains are too puny to handle it.

Maybe this level of universal obfuscation is now just par for the
course, when manufacturers, themselves, _all_ start giving their
newly produced chips -- the ones that draw 2 watts and produce
just twice the lumens of their previous 1 watt chips -- the
title "3 watts". But _I_ don't think of this as a "good thing".

Is it just me? Or do Buffalo Wings taste like chicken?


- lenngray -

 

[Hosebomber]

Re: LED lumens - sanity check ?!!

Wow, I'm not really sure where to start. Basically, the information they gave you has nothing to do with LED lighting. NO red or blue LED comes close to 100 lumens per watt. Lumens are not used in the measurement of LEDs because it's not a valid test method. Lumens is a measurement of how bright the light is to the human eye. It has nothing to do with growing plants. 90 watts of power consumption LED is about 1/5th of power output of a 400 watt HPS (it uses roughly 437 watts total depending on brand... that's within 2% of 1/5th). The naming of LEDs as 1, 2, 3, 5, or 10 etc watts is arbitrary. This is done as a means of fast recognition. A 1 watt led pulls 350mA, 2 watt 500mA, 3 watt 750mA (these are max ratings)... a 3 watt LED pulls 3 times the amperage that a 1 watt does. actually wattage changes from color to color because the voltage used to excite the chemicals used to make that color requires a different voltage.

There are a number of good discussions on these boards about figuring out what you need to know about LEDs, have a look around. FYI: 90% of companies claiming to use bridgelux are lying... they don't make most of those nm range LEDs any longer and haven't for at least 3 years.

 

[lenngray]

While I may have been a little lax in my language, referring
to "lumens", you seem to have some misconceptions behind your
logic believing that "numbers don't mean anything". Lumens
_are_ absolutely meaningful though the perceptual luminosity
function does count. But, while its true that the perceived
luminosity of a 620-630nm Red is way down at 31%, that's only
relative to a monochromatic 555nm GREEN. White ain't any
touchstone because it has lots of non-green components. The
luminosity of a white LED is at _most_ 44%, with a 5800K white
being only 37%, so _do_ learn a little about what is called
"the language of science".
(Maybe see Luminous efficacy - Wikipedia, the free encyclopedia
and Luminosity function - Wikipedia, the free encyclopedia)

But, in practice, right now, this very moment, for sale at:
High lumens 1W 3W high power led in Red - Detailed info for High lumens 1W 3W high power led in Red,high power red,High lumens 1W 3W high power led in Red,TD-T350IR1W TD-T700IR3W on Alibaba.com

is a 1W Red LED where you'll see: "620-630NM:1W 60-70LM"

That's 60-70 lumens for a 1 watt diode. The numbers are
there, if you're not invested in selling "there's no way to
know". And at $0.30-$1 per piece, I'm confident it's nowhere
near the best that can be had. BTW, do note that Alibaba
is a major industrial supplier, so a "they lie" claim won't be a
credible answer.

You write with so much faith in what you "know", as to say
30 lumens per watt is fine, because nobody else can possibly
know anything meaningful, that you're just willing to foist
ignorance, without even taking the 20 minutes I did to find
that offering on the net.

The idea that "3 watts is arbitrary" is _so_ over the top
that I can't even comment without getting insulting. You've
heard of Volts and Amps? You think those are a matter of
_opinion_?

 

[Hosebomber]

Either you think you know a lot more than you do or you simply can not comprehend what I said. I said the naming of LED's as 1, 3, 5, 10 etc watts is arbitrary. They are doing that as an easy identifier to the buyer. NO led on the market pulls the exact wattage of it's labeling.

Lumens, luminous efficacy and luminosity efficiency function have NOTHING to do with growing plants... they are all about how the human eye sees light.

Alibaba.com is not a major industry suppler. They are a middle man company that resells products (wholesale re-seller), they do however have very large volume of sales. They do not manufacture anything, therefore, they can not be a supplier.

If you want to attempt to correct me please use something I have said. Nowhere did I say anything about "30 lumens per watt is fine". 60-70 lumens is very close to the best out there for a 630nm Red LED. I don't have all of my datasheets with me currently but I believe 72 is currently the highest. That is a HUGE leap from 100 lumens per watt at 630 nm. It took 5 years for the industry to go from 87 lumens per watt to 120+ where it is currently at and this is by far where the largest market share and amount of research is focused.

I have no idea what the statement: "The numbers are there, if you're not invested in selling "there's no way to know"." is suppose to mean.

Directly from your link you take so much stock in:
Description of Red 1W High power led &3W led diode
1) Emitted color: Blue
2) Forward Voltage:3.0-3.6V
3) Viewing Angle: 60,90,120,140 Degree are optional
4) The wavelength 620 to 730NM are all available
Red 620-630NM:1W 60-70LM&3W 80-120LM
Deep Red 640-650-660NM: 1W 30-50LM&3W 40-70LM
IR 730NM :1W 200-300MW &3W 300-400MW
6)Chip brand: Epistar ,Bridegelux and Cree are available

It emits blue light at the 620-730nm range. Beyond the obvious type-o, The farther away you get from green (as you stated) the lower the lumens drop. Likewise, Bridgelux does not manufacture red LED's at all.

I'm pretty sure that I mentioned how volts and amps work and their relation to the "wattage" of LED's and how they are labeled in my prior post. Feel free to attempt to insult me, I have plenty of knowledge, research, testing, and peer-reviewed articles to back up what I say, so bring your A game if you try.

 

[lenngray]

So, FYI,
Going to DigiKey, my actual supplier-of-choice (almost nothing was
available last time I looked), Cree's XPERED-L1-00801, running at
350ma, produces 101 lm/W @ 625nm, and OSRAM's LA-CP7P-KPKR-1, at
350ma, produces 104lm/W @ 624nm, so thanks for the disinformation,
saying 30lm/W was fine and that red can't approach 100 lumens/W.

Go ahead, show me how much you know, that I can't find out.

 

[lenngray]

Clearly, the "blue", in Alibaba's listing is a typo, but
the listing, for 620-730nm, is for the choice of 3 different
types -- Red, Far Red, and IR, as your own cut-and-pasted
text conveyed. They also have a choice of 1W and 3W, and
60,90,120 and 140-degree spreads, and those don't all have
to be talking about the same chip. Do you think they do?

Further, a supplier is not a manufacturer -- a supplier is
a distributor. Most people do not even have access to buy
from manufacturers, so a manufacturer is not even a supplier.

But going back to what you asked for:

"If you want to attempt to correct me please use something
I have said"

Okay, you said:

"NO red or blue LED comes close to 100 lumens per watt."

and your implication was that _I_ was full of shit, and
that criticizing the ad's 30 lumens per watt in asking about
the 100 lumens per watt, was just stupid.

Yeah, let's _do_ get to substance in trading insults. But
don't expect to hide behind ambiguities, or have a lie-by-
implication ignored. I do undetstand, statistically, what
actual people get from the written and spoken word.

Do you work for one of the light manufacturers? Sure does
sound like you're invested.

 

[Hosebomber]

Ok, first and foremost, I never said anything about 30lm per watt other than quoting you. As I showed in my last post (with an admitted type-o) white LEDs took 5 years to go from 80lm per watt to over 120. White LEDs is where all the research and money gets put first because it is the largest market. All of that is irrelevant to the grow lighting arena because lumens is a measurement of the human eye and not plant photo-receptors. As for your prior post I'll point out all of the correct numbers since you can't read a data sheet.

Digikey link to Cree you mentioned:
Luminous Flux @ Current - Test 74 lm
Lumens/Watt @ Current - Test 101 lm/W
Current - Test 350mA

Digikey link to Osram you mentioned:
Luminous Flux @ Current - Test 80 lm
Lumens/Watt @ Current - Test 104 lm/W
Current - Test 350mA

*EDIT*: According to Osram this LED actually has a 617 dominate wavelength not 624 (which is max). This might explain the higher flux values at 80 vise 74 for Cree. I don't have any of these and It appears to only be sold in reels so I probably won't get any to even test them, mostly because they are SMD only.

As you can see, they produce 74 and 80 lumens respectively when driven at the 1 watt (350mA) current. The LED is not a "true" 1 watt LED and it does not produce 100+ lumens until it is ran above 350mA. I may have been unclear in a prior post mixing lumens produced vise lumens per watt. The fact is that no led currently on the market can be driven at 350mA and produce 100 lumens of light in the red 630ish nm range.

I do not work for any light company currently or have I ever worked for any that are part of the grow lighting market. One last time, I never mentioned 30lm was fine, you might want to stop referring to your own statement as something I have said. I will concede that I mis-spoke on the "producing 100 lumens per watt", that should have read 100 lumens driven at 1 watt (350mA). Cree now has one that is 74 lumens ( I said I believed the current highest was 72). I will also admit that I was unaware of the claimed 80lm LED by Osram, mainly because they are very expensive and not easily acquired in exact binning with consistency.

For those people that are reading this to gain knowledge on the LED market and how LEDs work with growing plants... disregard all of this. Lumens are not a measurement that should be used when referring to LEDs in any form other than how bright the light is to the human eye. Plants do not have human eyes and a better measurement to use would be PAR.

 

[lenngray]

Hey Skater,

As an engineer (which I am!), if I couldn't confirm that
Alibaba actually had similar at cheaper prices, I'd use
300 Osram LACP7P-KQKS-W3 LEDs running at 2.2V and 350ma,
624nm, giving 113 lm/w, for a total of 26103 lumens of
Red from an actual 233 watts of power. Ignoring driver
efficiency for now, that'd give narrowband red panel for
an LED cost of $269 if bought from DigiKey. That'd be
113 lumens per watt of electrical power for Red.