COB efficiency Spreadsheets

CanadianONE

CanadianONE

Well-Known Member
dimebagor said:
ok , so you mean , better is to run an cxb3590 for example , at 700ma , than at 1.2A which give more lumens but less PAR , for a bigger yield always ?

The second question is about the behavior of light when mix cob with monocolor led , like this panel : http://www.lcdph.fr/details-systeme declairage horticole led spectra module x85-76.html

does the wavelength of the blue mono color ( and others) the mixed with the cob spectrum ?
How it goes ? they add their intensity ? the color which is mixed at the crossed point : blue led's crossed yellow wave cobs so for the leaf its green wave she received ?? )
And in what circumstance the will add , cuz the wave cbos are more power than mono color huh ?
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Forget lumens all together there a bad measure of light for plants.
For your example CXB3590 CB 36V @ 700ma VS CXB3590 CB 36V @ 1.4A
if 700ma 22.9 watts @ 58.71% efficiency 22.9 x 58.71% = 13.45 par watts / 9.94 heat watts
if 1.4A 48.85 watts @ 51.67% efficiency 48.85 x 51.67% = 25.24 par watts / 23.61 heat watts

So if you run twice as many COB's at lower current you get more PAR watts compared to running less COB's at higher current.

4 @ 700ma = 91.6 watts / 53.8 par / 39.76 heat

2 @ 1.4A = 97.7 watts / 50.48 par / 47.22 heat

Upfront cost is higher but you don't have to dissipate as much heat, get more usable light, use less electricity & your LED's would last longer as well.

As far as your question for mixing mono's with white led's, I think most just believe that the COB's are producing a good spectrum and don't want to fuss with the mono's. But I am sure there are some benefits to adding some mono's to get the spectrum exactly where you want it. I can't say for certain because I am still relatively new to the LED scene myself but I don't believe the color spectrum from a mono would mix with a while led as you asked.
 
Meinolf

Meinolf

Well-Known Member
dimebagor said:
does the wavelength of the blue mono color ( and others) the mixed with the cob spectrum ?
How it goes ? they add their intensity ? the color which is mixed at the crossed point : blue led's crossed yellow wave cobs so for the leaf its green wave she received ?? )
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Your eye translates the mixed spectrum, you see (a reflection of) green, but the individual waves, consisting of photons of different "spins" are still there. If you look from the perspective of the plants, you still see blue and yellow diodes. The individual waves are still hitting the chloroplasts and its contained pigments and are ultimately transformed to chemical energy and to heat. If you mix light sources of differing spectra and radiation powers you will have slightly differing ratios of light hitting the plant in different zones. I think this is negligible result-wise, but in theory the cells in different zones will perform differently. I would advocate for mixing the spectra/overlapping the light cones as evenly as possible. However, it's still questionable whether it's worth the hassle, since after all our plant (at a certain height) is using 95% [sic] of all the photons it is irradiated with, about 25% of which for photosynthesis, the remainder for heat that is utilized in transpiration, so ultimately for CO2, water and nutrient uptake.

Edit: 95% is for very dim light. The higher the radiation, the more light is reflected. I think SDS conducted an experiment with a result roughly 15% reflection?
 
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OneHitDone

OneHitDone

Well-Known Member
CanadianONE said:
Forget lumens all together there a bad measure of light for plants.
For your example CXB3590 CB 36V @ 700ma VS CXB3590 CB 36V @ 1.4A
if 700ma 22.9 watts @ 58.71% efficiency 22.9 x 58.71% = 13.45 par watts / 9.94 heat watts
if 1.4A 48.85 watts @ 51.67% efficiency 48.85 x 51.67% = 25.24 par watts / 23.61 heat watts

So if you run twice as many COB's at lower current you get more PAR watts compared to running less COB's at higher current.

4 @ 700ma = 91.6 watts / 53.8 par / 39.76 heat

2 @ 1.4A = 97.7 watts / 50.48 par / 47.22 heat

Upfront cost is higher but you don't have to dissipate as much heat, get more usable light, use less electricity & your LED's would last longer as well.

As far as your question for mixing mono's with white led's, I think most just believe that the COB's are producing a good spectrum and don't want to fuss with the mono's. But I am sure there are some benefits to adding some mono's to get the spectrum exactly where you want it. I can't say for certain because I am still relatively new to the LED scene myself but I don't believe the color spectrum from a mono would mix with a while led as you asked.
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This is not pure led but illustrated "mixing" of white and mono red led.
Inda-gro pontoon only and in combination with the induction white
PontoonON.jpg Pontoon+Induction.jpg
 
D

dimebagor

Well-Known Member
Ok guys thanx for all precision :)

i supposed then in term of photon ( particle so , not wawe ) when light emited from an Olson deep red placed near from an Cob ,the when this Olson red light crossed more energetic Cob's photon , their energy are added together ?

One way to make more "efficiency" the monocolor led , at least for best luminosity penetration , specially about Red led who run max for the best at 700ma if i dont get wrong ?
Possible physically to make monocolor cob ? like blue royal cob ect ....
 
ttystikk

ttystikk

Well-Known Member
alesh said:
The future seems bright ans saturated :) High CRI CXB3590s in Supra's charts
Bad thing is that prices are quite high. It would be awesome if KB had some for a better price.
View attachment 3500421
View attachment 3500422
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80 CRI for a lot of these chips seems entirely adequate to me. What's the upside of even higher CRI? I'm hoping you can help me justify my 860W CDM lamps- their CRI is 93!
 
ttystikk

ttystikk

Well-Known Member
alesh said:
A lot of output in the deep/er red region. If a standard-CRI and a high-CRI warm white LED had the same output, the high-CRI one would be probably better as it has "better spectrum" IMO.
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I guess I'd need to see 'better' quantified. HPS spectrum sucks, for instance- but it grows millions of pounds of product every year.

I switched to 860W CDM lamps and nothing magical happened.
 
SupraSPL

SupraSPL

Well-Known Member
Currently that is true, but if the CXB3590 3K BD 90CRi was available for the same price, might be worth a shot. It matches the efficiency of the CXB3590 3500K CD but the spectrum should be a bit more photo synthetically efficient, more red without sacrificing blue. I do agree that spectrum is les important than originally suspected but on the other hand it does make sense to make use of the red spectrum. On the other hand maybe high CRi has too much of its output above 700nm and maybe and 80 CRi would actually prove better?

@alesh thank you for that data, it looks like those numbers are based on 380-780nm, do you have an idea which one makes the most sense to focus on or should we look at both? (400-700nm) If I understand correctly the human vision curve 380-780 is used for lumens and we are using lumens to estimate the COB efficiency, but for PPF and PPFD we are looking for PAR so should we switch to 400-700 at that point? I figure this is especially important question when looking at 3000K and high CRi COBs.
 
alesh

alesh

Well-Known Member
SupraSPL said:
Currently that is true, but if the CXB3590 3K BD 90CRi was available for the same price, might be worth a shot. It matches the efficiency of the CXB3590 3500K CD but the spectrum should be a bit more photo synthetically efficient, more red without sacrificing blue. I do agree that spectrum is les important than originally suspected but on the other hand it does make sense to make use of the red spectrum. On the other hand maybe high CRi has too much of its output above 700nm and maybe and 80 CRi would actually prove better?

@alesh thank you for that data, it looks like those numbers are based on 380-780nm, do you have an idea which one makes the most sense to focus on or should we look at both? (400-700nm) If I understand correctly the human vision curve 380-780 is used for lumens and we are using lumens to estimate the COB efficiency, but for PPF and PPFD we are looking for PAR so should we switch to 400-700 at that point? I figure this is especially important question when looking at 3000K and high CRi COBs.
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The photon output includes all the photons in the 380-780nm range no more no less. I don't know whether we should use the 400-700nm range or not. I'm quite curious what range various commercial lights use.
 
Greengenes707

Greengenes707

Well-Known Member
Aleshs sheets have the QERfor both all phonton(380-780) and visible(400-700).

The QER for all photons for 90cri is higher than 80cri. But when looking at just 400-700...the 80cri's QER is higher than 90cri. Because of that mostly over 700nm output like supra is referencing. So to look at it in a different way...the 80cri has ~3.5% more photon output within 400-700, but less total. Tangent thought...applying the RQE to each spectrum might negate that small lead within 400-700 anyways.

I am in the camp of using and reporting all photons. 700-725nm has a pretty active RQE(>25%)...specially for an area that people are omitting all together. Add that too the studies of cannabis reflectance over its whole cycle and I see no reason what so ever to restrict to 400-700nm. Plants use and want that deep/far red.
 
Meinolf

Meinolf

Well-Known Member
"light with a wavelength greater than 680nm is much less efficient [in driving oxygen evolution] than light of shorter wavelengths" (Taiz et. al. 2015: 179)

So most of that deep-/far-red light will become tissue heat, but that's not necessarily a bad thing, because the heat is driving transpiration, therefore gas exchange and nutrient uptake (Sometimes with led only my temperatures are too low). The high 730 proportion may also give a lot more stretch, but might as well be somewhat beneficial to multidirectional cob lighting (Some LED buds get extremely dense to the point of bud rot menace).

The results would have to be compared to give an educated guess on the efficacy of such high CRI spectra, and the aligning efficiencys make it possible to do so. I suppose a lot of people will try. What's the price of a unit anyway?
 
Darth Vapour

Darth Vapour

Well-Known Member
ttystikk said:
80 CRI for a lot of these chips seems entirely adequate to me. What's the upside of even higher CRI? I'm hoping you can help me justify my 860W CDM lamps- their CRI is 93!
Click to expand...
the upside of Higher CRI is full spectrum and nothing beats the sun @ 100 CRI

Anyways i been doing some reading about light Efficiency One of the basic laws of physics is the law of the Conservation of Energy. This simply states that energy cannot be created or destroyed, it can only be transferred from one form to another. So when a 100watt lamp is switched on, 100 watts of electrical energy is converted to 100watts of light and heat; a 50watt lamp produces a total 50 watts of light and heat, and so on.* However, some lamps are more efficient at producing light than others; this determines how much of that 100 watts is transformed into light, and how much is "wasted" and comes out as heat
An incandescent lamp is an extremely inefficient light source. According to the Wikipedia online encyclopaedia, a 100 watt bulb is 2.1% efficient. In other words, it produces about 2 watts of light and 98 watts of heat.

A halogen lamp is a bit better. For every 100 watts you put in, you get about 3.5 watts of light and 96.5 watts of heat.

Fluorescent lamps are said to be about 8.2% efficient, and although there were no figures on Wikipedia for mercury vapour lamps, I found one reference saying they were about as efficient as fluorescent lamps, and another that said they were three times as efficient as incandescent lamps... so we're looking at 6 - 8% efficiency here. 100 watts of electricity will be converted to, at most 8 watts of light (including UV light) and 92% will still come out as heat.

So the main factors which determine how much heat a lamp puts out, are what type of lamp it is, and its wattage.

However, the heat and light from a lamp can be emitted in all directions, or focused on a small area (consider the heat and light you might experience sitting 2ft below a 60 watt frosted "globe" lamp as opposed to a 60 watt narrow beam spot lamp) hence the shape of the lamp, the type of glass surface and the presence or absence of reflectors, such are found inside spot lamps, will also play a major part in determining how hot a basking spot gets directly under any lamp, of whatever wattage.

So has anyone actually figured out how much light percentage to heat percentage on the Cobs
 
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