Chinese -Leds
- Thread starter Don Geno
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SupraSPL
Well-Known Member
It may sound like bluster, but it is not far fetched. Cree stands behind their figures but you can knock yourself out testing them all you like 
I run my vegging lamps at 200lm/W (CXA3590 5000K CD bin running at 270mA, dissipating 18W ea, Tj ~30C, 62% efficient). I plan to run them at 200mA at the next upgrade. Vegging lights run even longer each day so if you crank the efficiency you can almost eliminate the heat that is contributed from the vegging room
Here is a CXA3070 3000K AB bin running at 150mA with a Tj of ~25C. Approximate efficiency 62.5% or 203lm/W. Dissipation is about 5W, cost about $18/PAR W. Of course I don't run them this soft, it is just a demonstration, but if you were so inclined it could be done. Just a matter of what you are willing to pay for and of course the law of diminishing returns.
$1.25 for 150mA driver. $42 for CXA3070 AB, $1 for used heatsink from ebay = 203lm/W
I run mine at 700mA, which is approx 52.3% efficient or 170lm/W. The cost was not that bad at all, about $3.30/PAR W. I recently paid $7/PAR W for deep reds. I paid more than $10/PAR W for my earliest DIY lamps buying parts from KNNA.
There is one warm white COB that is even more efficient than the CXA3070 3000K AB and that is the CXA3590 3000K CB. Rare but they do exist and some RIU members are building with them (not me unfortunately though
)
I run my vegging lamps at 200lm/W (CXA3590 5000K CD bin running at 270mA, dissipating 18W ea, Tj ~30C, 62% efficient). I plan to run them at 200mA at the next upgrade. Vegging lights run even longer each day so if you crank the efficiency you can almost eliminate the heat that is contributed from the vegging roomHere is a CXA3070 3000K AB bin running at 150mA with a Tj of ~25C. Approximate efficiency 62.5% or 203lm/W. Dissipation is about 5W, cost about $18/PAR W. Of course I don't run them this soft, it is just a demonstration, but if you were so inclined it could be done. Just a matter of what you are willing to pay for and of course the law of diminishing returns.
$1.25 for 150mA driver. $42 for CXA3070 AB, $1 for used heatsink from ebay = 203lm/W
I run mine at 700mA, which is approx 52.3% efficient or 170lm/W. The cost was not that bad at all, about $3.30/PAR W. I recently paid $7/PAR W for deep reds. I paid more than $10/PAR W for my earliest DIY lamps buying parts from KNNA.
There is one warm white COB that is even more efficient than the CXA3070 3000K AB and that is the CXA3590 3000K CB. Rare but they do exist and some RIU members are building with them (not me unfortunately though
)
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nomofatum
Well-Known Member
The best I can find from a credible source is 135lm/watt for a CXA3070 (with expensive cooling), can you link to anything credible over 140lm/watt? Especially a 170lm/w or 200lm/w as you claim?
SupraSPL
Well-Known Member
Sure, the Cree PCT shows the CXA3590 CD bin at 176lm/W but they do not give us test data in the PCT that goes as low as I am driving them. I extrapolated the numbers from the PDF data.
It also shows the CXA3070 AB bin at 174lm/W at 350mA. The PCT is not perfect though. It is not even asking us to designate the color temp, which would affect the lumens/W, although not by much. The LER for the 3000K 4000K and 5000K are very close..
This chart is the current droop for the CXA3590. You can simply multiply the nominal lumens by the factors listed in the graph and then divide by the dissipation (requires the Vf curve)
CXA3590 current droop curve
CXA3590 Vf curve
CXA3590 5000K CD bin at Tj 50C, typical figures
CXA3070 3000K AB bin at Tj 50C, typical figures
It also shows the CXA3070 AB bin at 174lm/W at 350mA. The PCT is not perfect though. It is not even asking us to designate the color temp, which would affect the lumens/W, although not by much. The LER for the 3000K 4000K and 5000K are very close..
This chart is the current droop for the CXA3590. You can simply multiply the nominal lumens by the factors listed in the graph and then divide by the dissipation (requires the Vf curve)
CXA3590 current droop curve
CXA3590 Vf curve
CXA3590 5000K CD bin at Tj 50C, typical figures
CXA3070 3000K AB bin at Tj 50C, typical figures
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SupraSPL
Well-Known Member
Ironically, Cree proclaimed with fanfare that the MK-R finally broke the 200lm/W barrier, but the data from their own PDF does not back that up, even top bin running soft. But they never promoted the CXA3590 for reaching 200lmW, even though the PDF data does back it up this time. From what I have seen it is the most efficient white LED ever released (the CD bin).
LurchLurkin
Active Member
I can't support any side, but lumens aren't used by plants, PAR is, and it's measured in einsteins, also.. It's pointless if you exceed what the plant can handle over a given area at that point.
Abiqua
Well-Known Member
He estimated the PAR, which is efficiency %. Lumens is mentioned to compare the brightness of two similar spectrums, in this case 3k.
We all know the lumen argument, but again, the lumen range just so happens to mimic most of the par range....clearly he is not suggesting anyone use lumens to determine their product, they are merely comparing two like sources where lumens are offered by the datasheets at a given efficiency....as coincidence of Voltage x Watts and Efficiency produced....
LurchLurkin
Active Member
I don't have the study on hand but at about 80 degrees and 1200ppm the government found cannabis could only handle 2000 Einstein. I also recall hearing plants can run better in the mid 90s, but I'm not sure on this, and there was skepticism on affect on yield, I believe ed Rosenthal was part of that info but I'm only sure on the government study as Ive knocked a few back. Clearly co2 would need to be higher. Also, lumens aren't comparable to par and to tout the effectiveness of some efficiency someone needs to measure par. Also need to consider penetration and how much it diminishes with distance as Led don't follow the same law as hid.
SupraSPL
Well-Known Member
Yes for those reading this, please understand we are only talking about lumens because we are dealing with white LEDs. lumens/W needs to be converted into PAR W or umol (microeinsteins per second per square meter (μE m−2 s−1)) to be useful because it varies for each color temp. We can't even directly compare lumens for the 3000K Vero and the 3000K CXA because their curves are slightly different.
All that said, sometimes lumens are all we have to go by and we are doing our best to work with what we have.
As far as CO2 and temp, I do believe you can pack on more weight with bumped up CO2 and temperature, but I wonder how much more cannabinoids that really translates into? Granted, commercial growers may not care, but it could be handy to have an edge over the competition and gain a reputation for having more potent weed. In other words, if quality has to take a hit with the higher temps, I personally wouldn't go that route.
Regarding intensity, I agree there is a law of diminishing returns when it comes to photosynthesis. Using LEDs, we can increase the intensity as high as we want. But I am a student of KNNA and in the interest of efficiency, we have never tried to match the intensity of the sun, call it 1500ppfd. We are aiming more in the 800-1000 ppdf range. Best to put our effort toward even lighting and efficient use of the canopy space. You can still get good nug size in that intensity range.
Harvest from an 4'X5' canopy lit with about 15 PAR W / ft² or 755 PPFD
All that said, sometimes lumens are all we have to go by and we are doing our best to work with what we have.
As far as CO2 and temp, I do believe you can pack on more weight with bumped up CO2 and temperature, but I wonder how much more cannabinoids that really translates into? Granted, commercial growers may not care, but it could be handy to have an edge over the competition and gain a reputation for having more potent weed. In other words, if quality has to take a hit with the higher temps, I personally wouldn't go that route.
Regarding intensity, I agree there is a law of diminishing returns when it comes to photosynthesis. Using LEDs, we can increase the intensity as high as we want. But I am a student of KNNA and in the interest of efficiency, we have never tried to match the intensity of the sun, call it 1500ppfd. We are aiming more in the 800-1000 ppdf range. Best to put our effort toward even lighting and efficient use of the canopy space. You can still get good nug size in that intensity range.
Harvest from an 4'X5' canopy lit with about 15 PAR W / ft² or 755 PPFD
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over here you pay more like 0.25-0.28Eur/kwh, your argument is invalid
nomofatum
Well-Known Member
My argument is valid regardless of the price of electricity, it just takes less time for the more efficient option to pay off if you are being screwed on electricity costs. Silly illogical minded folks.
Positivity
Well-Known Member
thats why i keep things simple..use what works..
If peeps would just show grow journals along with their claims it'd be a lot more interesting.
I just see a lot of fluff and what ifs...
Led hasnt exactly been killing hid in overall bud size. Some people are trying to push the limits of the current tech. Epis aint gonna do it...simple as that.
But you want something to grow, your low on money, and low expectations....get epistar. Then again..i take that back...build a light based on veros. Don't want to build? Buy a cmh.. .too expensive? Get a hps.
Where epi is a good idea I have no clue. Of course, thats going by documented grows and not conversation
If peeps would just show grow journals along with their claims it'd be a lot more interesting.
I just see a lot of fluff and what ifs...
Led hasnt exactly been killing hid in overall bud size. Some people are trying to push the limits of the current tech. Epis aint gonna do it...simple as that.
But you want something to grow, your low on money, and low expectations....get epistar. Then again..i take that back...build a light based on veros. Don't want to build? Buy a cmh.. .too expensive? Get a hps.
Where epi is a good idea I have no clue. Of course, thats going by documented grows and not conversation
I'd say epi fixtures are good for short grow spaces where you can't fit a CMH (and don't want to DIY an LED fixture). I think Cree "lightbulbs" are better for such circumstance. T5HO would be about the same as the lightbulbs (if someone didn't want to deal with all the socket arrangement, power distribution, etc.). But, in this short space, "better" is on a very small scale. A $100 TopLED/Vipar-eBay UFO would work relatively well for a minimal expenditure. A 2-foot (4-tube) T5HO is about $120. They both do about 28w/sq ft. Either way, supplemental light would be needed to get up to around 40w/sq ft. (Two fixtures?).
Sometimes I wonder if the extremely negative comments about Chinese epi-whatever fixtures result from a time when they were worse? For example, some people are really negative about autoflower strains. In some cases it comes out that their opinion arises from 3-4 years in the past. Genetics have apparently improved. (I grow a strain that heavy smokers say is exceptionally strong.). So, the "documented grows and not conversation" argument goes both ways. I'm kinda tired of people telling me a Chinese epi-whatever fixture won't grow in the above use case when I've gotten 1g/w right now.
I think we all agree on is that the rebranded Chinese epi-whatever lights (Kind, Lush, HydrogrowLED, Blackdog, GrowBlu) possess an exceptionally bad value proposition. For the price they charge, a fixture using reputable LED chips can be had.
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nomofatum
Well-Known Member
I believe the negative comes from it being Chinese and from it not being the top of the line version. The Chinese part is hilarious since Cree is also made in china along with almost all of the lighting options we use. Lots of idiot hypocrites on this site.
Greengenes707
Well-Known Member
You guys are fucking retarded for trying to say Cree CXA's are lumped into the term "China leds".
We refer to China as a general grouping for the 3-5 main factories in mainland china that produce 95% of the products on the market. They all use the same generic encapsulated leds that PERFORM WELL UNDER THE WORST HPS EFFCIENCY...which for idiots that have been try's to sound smart...effciency is output. And that lack in effciency means direct heat output.
The expienced and educated judge strictly on output/efficiency numbers...plus real world use.
Physics doesn't lie...more light is more buds...more efficient and thus higher output(per watt) leds will perform better and the numbers make it easy to see how much better. After the choosing of the best, then you maximize it by taking advantage of its thermal design to then maximize its real world performance...which means better output and lifespan.
Let's also not forget that the 3-5 China factories are also averaging around 30+% failure rates...that is off the line. Then count all the lights tht fail/break by the time in use for a short time.
It has been easier in the past to lump the generic China models together and call them China lights...like I sad in my last rant...be specific, even if a "China" light...that way we can just show the actual numbers and you ignorant ungrateful fucks can do the math yourselves instead of listening to the actually educated and expirenced. Just because one is a tech nerd does not mean they are an LED growing guru or designer. Expirenced goes much farther than regurgitating some figures worked out by others.
We refer to China as a general grouping for the 3-5 main factories in mainland china that produce 95% of the products on the market. They all use the same generic encapsulated leds that PERFORM WELL UNDER THE WORST HPS EFFCIENCY...which for idiots that have been try's to sound smart...effciency is output. And that lack in effciency means direct heat output.
The expienced and educated judge strictly on output/efficiency numbers...plus real world use.
Physics doesn't lie...more light is more buds...more efficient and thus higher output(per watt) leds will perform better and the numbers make it easy to see how much better. After the choosing of the best, then you maximize it by taking advantage of its thermal design to then maximize its real world performance...which means better output and lifespan.
Let's also not forget that the 3-5 China factories are also averaging around 30+% failure rates...that is off the line. Then count all the lights tht fail/break by the time in use for a short time.
It has been easier in the past to lump the generic China models together and call them China lights...like I sad in my last rant...be specific, even if a "China" light...that way we can just show the actual numbers and you ignorant ungrateful fucks can do the math yourselves instead of listening to the actually educated and expirenced. Just because one is a tech nerd does not mean they are an LED growing guru or designer. Expirenced goes much farther than regurgitating some figures worked out by others.
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Positivity
Well-Known Member
I've owned 4 commercIal lights that use mystery bin diodes. They all sucked. The latest high tech ones with multi chips included. I couldn't even go a full run with the multichip because it worked better as a space heater.
Am I supposed to keep buying them till I find the right one?
The unnamed bin stuff is worthless in my opinion. They made that impression over years of use. Your buying the executives some nice rides and homes with all those 5c LEDS
Am I supposed to keep buying them till I find the right one?
The unnamed bin stuff is worthless in my opinion. They made that impression over years of use. Your buying the executives some nice rides and homes with all those 5c LEDS
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nomofatum
Well-Known Member
Lets break this apart.
China, means from China, aka Made in China. Where are Cree LEDs made? China. that isn't retarded, that is fact.
LED, means light emitting diode. Check there too.
So Cree LEDs are factually and correctly Chinese LEDs.
Positivity
Well-Known Member
Dont forget to include crees quality control oversight. Not to mention the night and day difference with their bin transparency
Hmmm...you seem to forget the important stuff.
Maybe your just playing devils advocate...its really not even worth the discussion other than reminding innocent buyers of whats a good led choice
Positivity
Well-Known Member
You better do a scrog...
Otherwise the cob side is going to wipe its butt with the epi