• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

Can a light get too efficient

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Schalalala

Active Member
:D Okay okay, I mixed the words up. Efficacy is wrong, efficiency is what i meant.
But please read the original post (and check the source, there is written that the COB was tested with 35V*1A). The test sheet says Strahlungsleistung, which is radiant power = 9,149 W.
Radiant Power divided through Electrical Power is - my fault, i am sorry - radiometric efficiency not efficacy. And thats where my 26 % came from.
Is there anyone who thinks that 26 % radiometric efficiency is acceptable for an LED which clearly targets growers?

And I fully understand why a spectrum with a lot of red has low lm/W ratings. I even analysed the Lumileds Red Meat spectrum and got a LER of 200.
Do you want me to repeat the examples with that LER :D ?
All I want to say is: Do not use the chinese grow COBs, not for anything. If you want to have a fatter red spectrum, the 1750 K bridgelux spectrum probably is the best.
If highest efficiency is what your after, the is no way around top bin monos.
 
nfhiggs

nfhiggs

Well-Known Member
nfhiggs said:
You comparison is extremely biased. Comparing radiometric efficiency to luminous efficacy is like comparing miles per hour to liters per minute.
Click to expand...
Furthermore, red heavy spectrums will have a much lower radiometric efficiency per mole of photons produced than blue (or green) heavy spectrums, given the same PAR efficiency (uMoles/Joule) Plants eat whole photons, not light watts. Complaining about the low radiometric efficiency of a 1800K spectrum is just silly. But comparing it to the luminous efficacy of a 3000K emitter is rather disingenuous.
 
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PurpleBuz

Well-Known Member
Schalalala said:
And I fully understand why a spectrum with a lot of red has low lm/W ratings. I even analysed the Lumileds Red Meat spectrum and got a LER of 200.
Do you want me to repeat the examples with that LER :D ?
Click to expand...
sure why not! or how about the PPF/j for all three of them while you are at it.

A deep red mono 660nm while certainly effective is not the same as the fat red zone phosphorous peak from the meat chips.
 
S

Schalalala

Active Member
nfhiggs said:
Furthermore, red heavy spectrums will have a much lower radiometric efficiency per mole of photons produced than blue (or green) heavy spectrums, given the same PAR efficiency (uMoles/Joule) Plants eat whole photons, not light watts. Complaining about the low radiometric efficiency of a 1800K spectrum is just silly. But comparing it to the luminous efficacy of a 3000K emitter is rather disingenuous.
Click to expand...
Are you familiar with the term LER and how you calculate it? Check out @alesh thread "The math behind". Its gold.

LER (Luminous efficacy of radiation, I googled it because now im afraid of using the wrong eff... again :D) tells me, how many lumens a specific spectrum makes from 1 W radiation power. If I divide the Luminous efficacy through the Luminous efficacy of radiation the units are:

(lumen/electrical power) / (lumen/radiation power) -> the lumens go away and all that is left is: radiation power / electrical power. Now I know how efficient my LED is.

If I want to how how many photons they bump out, then I have to know the QER (Quantum Efficiency of Radiation), which is also spectrum depended. This value tells me how many umoles i get per second and radiant power.

Then I have everything to get the photon

QER*LER*Electrical Power = Photons per Second.

So its not silly. Its the only way how to calc photon output if the manufacturer gives output in lumen.

The spectrum which pump the most (usuable) photons per radiation power out, is 660 nm with around 5,5 umols/s*W(radiant). Lets assume all the light that the LED emitted was 660nm. The real QER of this spectrum will be lower as blue photons contain more energy so following calculation is highly in favor of the chinese grow LED.

The german guy had the COB in his sphere and measured 9 W radiant output. Therefore we get:

9 W(rad) * 5,5 umol/s*W(rad) = 50 umol/s

The COB took 35 W electrical power.

We divide 50 umol/s through 50 J/s (which is Watt) and we get 1,43 umol/J. Thats fucking nothing.
 
nfhiggs

nfhiggs

Well-Known Member
Schalalala said:
Are you familiar with the term LER and how you calculate it? Check out @alesh thread "The math behind". Its gold.

LER (Luminous efficacy of radiation, I googled it because now im afraid of using the wrong eff... again :D) tells me, how many lumens a specific spectrum makes from 1 W radiation power. If I divide the Luminous efficacy through the Luminous efficacy of radiation the units are:

(lumen/electrical power) / (lumen/radiation power) -> the lumens go away and all that is left is: radiation power / electrical power. Now I know how efficient my LED is.

If I want to how how many photons they bump out, then I have to know the QER (Quantum Efficiency of Radiation), which is also spectrum depended. This value tells me how many umoles i get per second and radiant power.

Then I have everything to get the photon

QER*LER*Electrical Power = Photons per Second.

So its not silly. Its the only way how to calc photon output if the manufacturer gives output in lumen.

The spectrum which pump the most (usuable) photons per radiation power out, is 660 nm with around 5,5 umols/s*W(radiant). Lets assume all the light that the LED emitted was 660nm. The real QER of this spectrum will be lower as blue photons contain more energy so following calculation is highly in favor of the chinese grow LED.

The german guy had the COB in his sphere and measured 9 W radiant output. Therefore we get:

9 W(rad) * 5,5 umol/s*W(rad) = 50 umol/s

The COB took 35 W electrical power.

We divide 50 umol/s through 50 J/s (which is Watt) and we get 1,43 umol/J. Thats fucking nothing.
Click to expand...
Except you didn't DO all that - you just tossed some l/m/W numbers out there as if they were equivalent. This is like math class, is you're going to show different things are equivalent you need to show your work.

If they calculate to 1.43 uMole/J, that's is indeed not very efficient - but he is also capturing all of the heat energy produced and using it for other purposes. In that situation the efficiency is moot since all of the energy is used for one purpose or another.
 
GrowLightResearch

GrowLightResearch

Well-Known Member
Schalalala said:
Lumileds Red Meat spectrum and got a LER of 200.
Click to expand...
LER is luminous, it is not relevant.
PurpleBuz said:
A deep red mono 660nm while certainly effective is not the same as the fat red zone phosphorous peak from the meat chips.
Click to expand...
A OSRAM SSL Olson Hyper Red output about 70% radiant power compared to electrical watts.


For the Luxeon Fresh Focus Red Meat L2C5-RM001211E1900
43,610 lumens = 215 radiometric watts = 1120 µmol/m²/s PPFD.

The following graphs were created from the attached CSV txt files.
The values were measured with a spectrometer with a calibration traceable to NIST.
The LuxeonFreshFocusRedMeat215Watts.txt can be copy and pasted into @alesh Math Behind spreadsheet.
When I imported the actual measured watts into the Math Behind spreadsheet the LER = 204 and QER = 5.167

The measurements were taken about 1 minute apart with the CoB at the same height and intensity.
The graphs are normalized to the max value found in the CSV.
The CSV's contain the absolute measurements from 275 nm to 1120 nm





LuxeonFreshFocusRedMeat1120PPFD.jpg

LuxeonFreshFocusRedMeat215Watts.jpg
LuxeonFreshFocusRedMeat43610Lux.jpg
 

Attachments

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wietefras

wietefras

Well-Known Member
Oh come on he was trying to make it more tangible how bad 26% efficiency really is. Let's got get riled up because he used the word "efficacy" instead of "efficiency". He used the wrong word where the two have sort of a similar meaning. Big deal. He even corrected this. Done.

That's nothing compared to having someone around who thinks straight lines are "inverse square", that Chlorophyll charts trump McCree's charts etc etc etc etc.

Case in point, this shit he just posted.
GrowLightResearch said:
LER is luminous, it is not relevant.
Click to expand...
He truly imagines that lumen/lux and PPF/PPFD are two completely unrelated beasts and that the devices to measure these are totally different (one contains a CCD or CMOS chip to calculate angles!). He can't imagine that you could simply convert between the two by a simple multiplication or division factor. Even though there is a ton of evidence that you can

Or that he claimed QER isn't an actual thing, or that you cannot estimate average PPFD from PPF/surface area (or more accurately when PPF is done minus reflection losses). Seriously the list of nonsense coming from this "researcher" is endless.
 
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S

Schalalala

Active Member
nfhiggs said:
Except you didn't DO all that - you just tossed some l/m/W numbers out there as if they were equivalent. This is like math class, is you're going to show different things are equivalent you need to show your work.
Click to expand...
Dude, I compared the radiant efficiency of the china COB with the radiant efficiency of an LM561C. Plus I gave an example of how such a low radiant efficiency would affect the luminous efficiency of the LM561C. Equivalency at its best.
 
wietefras

wietefras

Well-Known Member
GrowLightResearch said:
A OSRAM SSL Olson Hyper Red
Click to expand...
For someone who whines about typo's like you do, it's "An OSRAM" and what is "Olson"? Is that a new led series from OSRAM? How can we trust anything you say if you write so poorly?

GrowLightResearch said:
output about 70% radiant power compared to electrical watts.
Click to expand...
Don't be pretentious. "radiant power compared to electrical watts" is simply called "efficiency". Mentioning efficiency without the temperature and current at which it was measured/calculated is useless.
 
regoob eht

regoob eht

Well-Known Member
mahiluana said:
you are a crabby little german NAZI from the most stupid www.grower.ch forum - and more stupid than you is only the tristan who delivered the datasheet.
when the datasheet does not even show Vf, If, no binning conditions and a cri of 0,0
i`m shure the one who bought the gonio-spectralmeter payed 2000$ for nothing - he is standing in the dark (CRI0,0) - and should have better spent it with his urologist having a deep look in his asshole
- measuring his prostata with this crappygonio
- ok will you ignore again and leave you in the dark :finger:
Click to expand...
Proctologist is a butt doctor.
Urologist looks up your pee hole. That's all I have to add. Carry on.
 
mahiluana

mahiluana

Well-Known Member
regoob eht said:
Carry on.
Click to expand...
OK. - next time I`ll put my latex gloves on
my 10 busy, quick fingers should be always enough to give a complete treatment to a fucking nazi or 2 ---i`m specialized in operating snotty noses and you can make an appointment @ the helpdesk >:(
 
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PurpleBuz

Well-Known Member
GrowLightResearch said:
LER is luminous, it is not relevant.

A OSRAM SSL Olson Hyper Red output about 70% radiant power compared to electrical watts.


For the Luxeon Fresh Focus Red Meat L2C5-RM001211E1900
43,610 lumens = 215 watts = 1120 µmol/m²/s PPFD.

The following graphs were created from the attached CSV txt files.
The values were measured with a spectrometer with a calibration traceable to NIST.
The LuxeonFreshFocusRedMeat215Watts.txt can be copy and pasted into @alesh Math Behind spreadsheet.
When I imported the actual measured watts into the Math Behind spreadsheet the LER = 204 and QER = 5.167

The measurements were taken about 1 minute apart with the CoB at the same height and intensity.
The graphs are normalized to the max value found in the CSV.
The CSV's contain the absolute measurements from 275 nm to 1120 nm
Click to expand...
After all that you didn't tell us what the PPF/Joule is for the meat chips and the cheap Chinese cob.... which is ALL we really needed to know.
 
mahiluana

mahiluana

Well-Known Member
PurpleBuz said:
you have no clue
Click to expand...
You do not grow or own a light.
Off switch activated.
Sorry, I can no longer participate. (Hybridway 2016)

seems that...these kind of mesages reaches you several times a year .........why ?
In this case...are you shure to have any clue about watercooled led light ?
Then show your pics,
give an argument...or shut up and leave your snotty glue in the bigmouth.
 
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