How Important Is Lumens Per Watt?

PetFlora

PetFlora

Well-Known Member
Most of you know I am not electrically inclined, and have resorted to off the shelf leds

Also, I see COB reflectors as the way forward

As much as I love to tinker...

Even I could probably build a COB/Reflector, but if I had problems, I have neither the equipment, nor know how to fix it

MedScientist bought an off the shelf cob light and got very good results

I just ordered 2 @ 75w advertised @ $77 + free shipping, but power consumption is ~ 48w, so what ~ 60w actual, or ~40w?

http://www.ebay.com/itm/Amazing-Growth-Reflector-Cup-75W-LED-Light-Grow-Panel-Integrated-COB-Hydro-Lamp-/190958710284?pt=US_Hydroponics&hash=item2c7606ae0c

Delving a bit deeper into the 'specs', I noticed the chip is ~ 75 lpw

So, is that good, poor..., is more better, and if so where is the threshold to high performance (as the plant sees it)?

FYI, i found anther cob reflector sold as 600w, draws ~ 330w, has dual switches and piggyback connectors < $350

http://www.aliexpress.com/store/product/Free-shipping-650W-hydroponics-led-grow-greenhouse-kits-with-lights/114449_1483155345.html


Would upgrading cobs be easy or necessary?
 
PSUAGRO.

PSUAGRO.

Well-Known Member
If I was going with a cheap chinese cob fixture, id look at these pet http://www.bsled.com/255W-ChloroBA-C2-LED-Grow-Light-127.html only $149, very specific details on their fixtures/warranty coverage. emailed them about the supposed "osram" cobs being used, will see.

lm/per watt are less of an issue when dealing with R-DR-B cobs/diodes, when using all "white" sources then it becomes important IMO==== HPS would be a total failure at 75lm per watt
 
PSUAGRO.

PSUAGRO.

Well-Known Member
wyteberrywidow said:
How did you come to those #'s? Curious:confused:
Click to expand...
Pet's led cob-chips^^^^ that he bought states 75lm per watt, just using it as a comparison:P........we mostly agree that HPS's strength is that 140-145lm per watt(600w hps), or is it that "favorable" spectra???lol
 
smokey the cat

smokey the cat

Well-Known Member
PetFlora said:
Most of you know I am not electrically inclined, and have resorted to off the shelf leds

Also, I see COB reflectors as the way forward

As much as I love to tinker...

Even I could probably build a COB/Reflector, but if I had problems, I do have neither the equipment, nor know how to fix it

MedScientist bought an off the shelf cob light and got very good results

I just ordered 2 @ 75w advertised @ $77 + free shipping, but power consumption is ~ 48w, so what ~ 60w actual, or ~40w?

http://www.ebay.com/itm/Amazing-Growth-Reflector-Cup-75W-LED-Light-Grow-Panel-Integrated-COB-Hydro-Lamp-/190958710284?pt=US_Hydroponics&hash=item2c7606ae0c
Click to expand...


That's a 75W LED COB, and it's being run at around ~40-43W. The missing 5-8W being used by driver and cooling etc.

I'd describe it as "40W of COB" - that number gives an accurate-ish description of what you're actually getting for your money, and will let you compare it pretty fairly against what the peeps in the DIY threads are assembling.


Delving a bit deeper into the 'specs', I noticed the chip is ~ 75 lpw

So, is that good, poor..., is more better, and if so where is the threshold to high performance (as the plant sees it)?
Click to expand...
This is poor compared to the best COB chips out there - but they are DIY only at the moment. It'll definitely grow decent enough bud. Looks like a great supplemental light - imho.

Lumens-per-watt tells you how much light you will get for a given watt. To get the same brightness with less efficient gear you just add more watts. You could plug in 10 cheap chinese COB panels and grow amazing stuff - it might not be as cheap to power as more efficient gear, but you just add more watts till your grow rocks. Plants only care about light - not about how much power you use giving it to them.


FYI, i found anther cob reflector sold as 600w, draws ~ 330w, has dual switches and piggyback connectors < $350

http://www.aliexpress.com/store/product/Free-shipping-650W-hydroponics-led-grow-greenhouse-kits-with-lights/114449_1483155345.html


Would upgrading cobs be easy or necessary?
Click to expand...
Retrofitting a new cob to a panel is possible - just depends on the driver inside the panel. Or you could replace the driver too if you felt like it. But far easier instead to assemble a COB light from scratch. Building a COB panel is much easier than growing weed - if you can handle a plant you can handle a build imho.

No doubt a name brand COB will be much more efficient than the generics, but obviously for a manufacturer it's much more expensive. And of course we can expect LED performance to increase similarly to what we have historically seen in the computer chip industry. I'm assuming with my micro-cab that I'll fit new COBs in a couple of years as the manufacturers eke out more efficiencies.
 
Abiqua

Abiqua

Well-Known Member
https://www.rollitup.org/led-other-lighting/722947-measuring-plant-lighting.html

Lumens and cri can be biased. Lumens may be a way to measure white only fixtures, but WW's will still be biased especially on the spectrums of red that are intensified. Cri is based on 14 boxes of color, outside of the boxes you a decrease CRI which does create a broader spectrum but lower CRI.

Mr. Flux has a calculation for LER/w and not just PAR which is think is interesting and hasn't been delved into, too much yet.....
 
SupraSPL

SupraSPL

Well-Known Member
PetFlora said:
Delving a bit deeper into the 'specs', I noticed the chip is ~ 75 lpw
Click to expand...
As psuagro pointed out, lumens can be useful in the case of white light but since your COB includes blue and reds you can expect the lumens/watt to be low. What we really need to know is the radiometric efficiency and the spectrum. That would allow us to figure out how many photons the lamp is putting out. Of course we rarely get that info about any LED, but we work hard to estimate it. To put it in perspective:

Fluoro tubes = 25% (brand new bulbs)
HPS = 36% (brand new bulbs)
no name china led = 15%
Area 51 LED = 30%
DiY LED = 39% (up to 48% if you are a big spender)
 
PetFlora

PetFlora

Well-Known Member
Thanks for all the input.

I'm sure I'm not the only one who will benefit

PSUAGRO

One hell of a find, and @ $149 woohoo

Could it really be 255w actual?

Hell that seems like a fair price for 100w

Finally glass reflectors + 180*s OMG

Please let me know if Osrams

EDIT I emailed them. Their Message board provides no real answers "sales person will get back to you"

Are you sure about the price?



PSUAGRO. said:
If I was going with a cheap chinese cob fixture, id look at these pet http://www.bsled.com/255W-ChloroBA-C2-LED-Grow-Light-127.html only $149, very specific details on their fixtures/warranty coverage. emailed them about the supposed "osram" cobs being used, will see.

lm/per watt are less of an issue when dealing with R-DR-B cobs/diodes, when using all "white" sources then it becomes important IMO==== HPS would be a total failure at 75lm per watt
Click to expand...
 
caretak3r

caretak3r

Well-Known Member
PSUAGRO. said:
If I was going with a cheap chinese cob fixture, id look at these pet http://www.bsled.com/255W-ChloroBA-C2-LED-Grow-Light-127.html only $149, very specific details on their fixtures/warranty coverage. emailed them about the supposed "osram" cobs being used, will see.

lm/per watt are less of an issue when dealing with R-DR-B cobs/diodes, when using all "white" sources then it becomes important IMO==== HPS would be a total failure at 75lm per watt
Click to expand...
no disrepect, but I think you may be off by a factor of 10 on the pricing:
http://www.alibaba.com/product-detail/wholesale-led-grow-lights-ChloroBA-C2_1477710565.html
 
Slipon

Slipon

Well-Known Member
I got a cheap light meter (measure in Lumens) I got for free back when I started to grow when I used +500$ at my local hydro store


And did test my 600W HPS and my 280W Bulldog LED panel with secondary lenses

DSC00850.jpg


DSC01376.jpg

I almost get the same Lumens from the LEDs as with the HPS at the same distance and the LEDs have a majority of Red LEDs wile the HPS of course are all white

My other LED panel with half the amount of white LEDs (8 instead of 16) and with no secondary lenses on em only give me about half the reading, when I get +5K foot candles from my Bulldog panel at around 20" I only get 2-3K from the LG with no secondary lenses on it, so I keep that at around 15" away, my HPS I could keep at 18" and 12" with a cool hood on it and got about 4-7K Lumens depending where I did measure, the LEDs give me 2-5K and same/better results
 
PetFlora

PetFlora

Well-Known Member
chuck estevez

chuck estevez

Well-Known Member
Slipon said:
I got a cheap light meter (measure in Lumens) I got for free back when I started to grow when I used +500$ at my local hydro store


And did test my 600W HPS and my 280W Bulldog LED panel with secondary lenses

View attachment 3011815


View attachment 3011816

I almost get the same Lumens from the LEDs as with the HPS at the same distance and the LEDs have a majority of Red LEDs wile the HPS of course are all white

My other LED panel with half the amount of white LEDs (8 instead of 16) and with no secondary lenses on em only give me about half the reading, when I get +5K foot candles from my Bulldog panel at around 20" I only get 2-3K from the LG with no secondary lenses on it, so I keep that at around 15" away, my HPS I could keep at 18" and 12" with a cool hood on it and got about 4-7K Lumens depending where I did measure, the LEDs give me 2-5K and same/better results
Click to expand...
A foot-candle is a non-SI unit of illuminance or light intensity widely used in the United States in photography, film, television, conservation lighting, the lighting industry, construction-related engineering and in building codes. Wikipedia





Related topics
Since illuminance follows the inverse-square law a source that is farther away casts less illumination than one that is close, so one lux is less illuminance than one foot-candle. Wikipedia
Explore: Illuminance, Lux

The name ``footcandle'' conveys ``the illuminance cast on a surface by a one-candela source one foot away''. Wikipedia
Explore: Illuminance, Candela

In the motion picture cinematography field, incident light meters are used to measure the number of footcandles present, which are used to calculate the intensity of motion picture lights, allowing cinematographers to set up proper lighting-contrast ratios when filming. Wikipedia
Explore: Light meter


Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. This spectral region corresponds more or less with the range of light visible to the human eye. Photons at shorter wavelengths tend to be so energetic that they can be damaging to cells and tissues, but are mostly filtered out by theozone layer in the stratosphere. Photons at longer wavelengths do not carry enough energy to allow photosynthesis to take place.



 
Slipon

Slipon

Well-Known Member
yea I know, would also like a Par Meter so I could check the Umol at different distances, but they are a bit costly and not so common, so had a hard time finding one last time I looked, so I gave up
 
You must log in or register to reply here.
Top