50 watts vs 100 watt cob

im4satori

Well-Known Member
what are the pros and cons to each comparing equal total watts in a fixture?

for example;

300 watt with 6 50watts cobs (con, cost more / pro, better light distribution)
or
300 watt with 3 100 watt cobs (would this be a better choice for taller plants?)
 
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Randomblame

Well-Known Member
Hi,
you'll get better distribution and more efficiency if you use the same COB's at 50w.

More effiency means more usable light so also the better solution for taller plants.

You can use 90° lenses or reflectors for instance to fokus the light for a "deeper penetration" if you prefer taller plants or use some additional vertikal LED-strips as side lights.
SunCloak is a very good solution for taller plants, @Hybridway has an own SunCloak thread, very very interesting!
The whole unit is strip based and built to create a full 360° light dome above your plants. For taller plants one of the best solutions IMO.
 

vertnugs

Well-Known Member
Curious about the same kind of things im4satori.

I have been eye ballin the Vero29 SE-X kit from cutter.Reason being is how the cobs are more efficient when run at a lower wattage which in turn produces more light.

But i don't know how 23.5 watts per cob would do as i have no experience with them.23.5 watts just seems so low.
 

ganjafather27

Well-Known Member
Curious about the same kind of things im4satori.

I have been eye ballin the Vero29 SE-X kit from cutter.Reason being is how the cobs are more efficient when run at a lower wattage which in turn produces more light.

But i don't know how 23.5 watts per cob would do as i have no experience with them.23.5 watts just seems so low.
More Cobs at the same total wattage, simply put gets better efficiency, better light spread with equals better coverage, better heat spread and you can run the cobs closer to the plants.

The main point of going diy led is efficiency, so when considering that, running more Cobs at a lower wattage per cob is a superior setup.

That boost in efficiency will save you money over time, via power consumption, but also has a higher up front cost, from needing more cobs/drivers/framework
 

CobKits

Well-Known Member
im not sure which veros are in that kit, but down around 20W theres not a lot of difference between chip efficiency so most people who run chips soft opt for cheaper chips so they can buy more of them

as far as strictly veros, youre not getting a lot out of a $35 veroC vs a $23 veroD at that wattage
 

im4satori

Well-Known Member
wouldn't a 100 watt fixture have a deeper penetration for a larger plant over a 50 watt?

also
if you run a 400 watt fixture dialed down at 50% power does it throw the same light as running a 200 watt fixture at full power

is there any cons to buying a larger fixture and running it dialed down?
 

CobKits

Well-Known Member
wouldn't a 100 watt fixture have a deeper penetration for a larger plant over a 50 watt?
it would have approximately 85% more ppfd at all points

if you run a 400 watt fixture dialed down at 50% power does it throw the same light as running a 200 watt fixture at full power
depends on the fixture and which diodes it uses

s there any cons to buying a larger fixture and running it dialed down?
it will be more efficient but the major con is you are buying capacity you dont need
 

im4satori

Well-Known Member
it will be more efficient but the major con is you are buying capacity you dont need
well I might run them at say 200 watts when there small ad increase the wattage as they get larger
but I don't want to be running dialed down to 200 watts and not getting the full monty
 

im4satori

Well-Known Member
it would have approximately 85% more ppfd at all points
im sorry

I am so far behind on the light tech I might as well be a cave man

I been running the old hps style magnestic ballasts for over a decade

just recently a few yrs back upgraded to the DE bulb and electronic ballast and was really happy wit the upgrade

so im going to be very ignorant with some of my questions.......

what does the above statement mean?

I see the ppfd ratings listed on the lights but I really don't know what that means

also Ive read some conflicting info on how these lights are rated (although I didn't fully understand it)
somewhere I read that ppfd was unreliable and that lumens per watt would be more accurate

but since I have no idea what ppfd is I might have completely misunderstood

if its a bit technical to explain maybe a link?
 

CobKits

Well-Known Member
what does the above statement mean?
it means that if you take an LED or cob and push it twice as hard it wont be 200% as bright, only about 185% as bright. the softer you run them the more effiicent they are which is why two cobs at 50W put out more light than a single cob of the same type at 100W

I see the ppfd ratings listed on the lights but I really don't know what that means
ppfd is just a spot measure of intensity like lux
ppf is the overall measure of a fixtures total output and is simialr to lumens

steer away from companies who sell fixtures and advertise ppfd readings without ppf measurement. most are unscrupulous and using spot measurements that are biased to make their lights look brighter than they are

also Ive read some conflicting info on how these lights are rated (although I didn't fully understand it)
somewhere I read that ppfd was unreliable and that lumens per watt would be more accurate
lumens are for humans, plants want PAR. ppfd is not unreliable, though as i meantioned the data can be used to exaggerate a fixtures performance. quality lights have efficiency stated in umol/J and is usually a number between 1.4 and 3.0.
 

im4satori

Well-Known Member
it means that if you take an LED or cob and push it twice as hard it wont be 200% as bright, only about 185% as bright. the softer you run them the more effiicent they are which is why two cobs at 50W put out more light than a single cob of the same type at 100W


ppfd is just a spot measure of intensity like lux
ppf is the overall measure of a fixtures total output and is simialr to lumens

steer away from companies who sell fixtures and advertise ppfd readings without ppf measurement. most are unscrupulous and using spot measurements that are biased to make their lights look brighter than they are


lumens are for humans, plants want PAR. ppfd is not unreliable, though as i meantioned the data can be used to exaggerate a fixtures performance. quality lights have efficiency stated in umol/J and is usually a number between 1.4 and 3.0.
now that im thinking of it

im not even sure ive even put my hands on an LED lol

ive always avoided even looking at them in the past cuz when I started out the cost was crazy and the tech not as advanced...so to keep myself from spending money on it I just avoided it...lol

http://www.fcopto.com/

when I look at this sight and I look at your avatar im seeing these flat colored disks and the one LEd I did see at the grow store was flat, thin and more like a sheet pan

where as he cob looks different visually...whats the difference?
 

xX_BHMC_Xx

Well-Known Member
Curious about the same kind of things im4satori.

I have been eye ballin the Vero29 SE-X kit from cutter.Reason being is how the cobs are more efficient when run at a lower wattage which in turn produces more light.

But i don't know how 23.5 watts per cob would do as i have no experience with them.23.5 watts just seems so low.
I'm running about 18w each right now. Most all COBs have a minimum drive current/voltage, and they just won't come on below that. The closer you can get to that minimum, the higher your theoretical efficiency will be. However, you reach a point of diminishing returns where parts and labor become much more than your power savings. Finding that balance is the key.
 

im4satori

Well-Known Member
so when comparing fixtures

your looking at the light spread,
watts consumed
ppfd
ppf
color spectrum

what do they mean by par watts or watts at the wall

for example
200 watts @ the wall
105 par watts
490 ppf
875 ppfd 18x48

and what does BIN refer to?
 

im4satori

Well-Known Member
now that im thinking of it

im not even sure ive even put my hands on an LED lol

ive always avoided even looking at them in the past cuz when I started out the cost was crazy and the tech not as advanced...so to keep myself from spending money on it I just avoided it...lol

http://www.fcopto.com/

when I look at this sight and I look at your avatar im seeing these flat colored disks and the one LEd I did see at the grow store was flat, thin and more like a sheet pan

where as he cob looks different visually...whats the difference?
would that be whats called a quantum board?
 

mauricem00

Well-Known Member
im sorry

I am so far behind on the light tech I might as well be a cave man

I been running the old hps style magnestic ballasts for over a decade

just recently a few yrs back upgraded to the DE bulb and electronic ballast and was really happy wit the upgrade

so im going to be very ignorant with some of my questions.......

what does the above statement mean?

I see the ppfd ratings listed on the lights but I really don't know what that means

also Ive read some conflicting info on how these lights are rated (although I didn't fully understand it)
somewhere I read that ppfd was unreliable and that lumens per watt would be more accurate

but since I have no idea what ppfd is I might have completely misunderstood

if its a bit technical to explain maybe a link?
seems like the whole COB crowd is behind on lighting technology. a large number of small LEDs would give much more uniform coverage and the new 561 strip lights can produce 165LPW and operate without heat sinks at 700ma. all they need is a simple wood frame to hold them and a little soldering to connect them.https://www.digikey.com/products/en?s=55345&v=976 these would work as well as quantum boards at a much lower cost and without heavy heat sinks and frames to hold them they would be a lot lighter
all light makers want you to think in terms that make their lights look good but the only thing that matters is how well it grows plants. lumens or PPFD does not tell you how much light the plants can use from a given source or if that source provide all the bands a plant needs. hps provides a high LPW rating but not much blue and violet that plants need.search youtube for grow videos to see haw lights perform with growers who know how to grow with the lights they are using. penetration is also misunderstood. if you want lights to get to lower buds you need to stretch or scrog your plant so there is a strait clear line of sight between the light and the lower buds.light can refract around a dense canopy but it can't go thru a dense canopy with usable intensity.use a little more red to stretch and open up your plants or top and train them (scrog) to expose lower buds sites
 

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im4satori

Well-Known Member
yes but if you've got a 30" tall plant that has some stretch or isnt super thick with foliage id still consider light intensity diminishing at further distances

assuming your canopy isnt so thick and you have the option to get light thru the plant .. how deep will the led push or at what rate does it diminish by distance

not to say its a fair comparison but more as an example;
a 1000 watt hps will push light deeper into the plant than a 400 watt hps

so would the same rules apply to the wattage on an LED between a 50 watt and a 100 watt
 
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