Trippyness
Well-Known Member
More like just over 900 in vero 29. However, am looking into lower ppfd.
Vero 29 V2 800PPFD 5 X 5 Question.
- Thread starter Trippyness
- Start date
BobCajun
Well-Known Member
Simple rule of thumb with the large COBs is 1 per sq ft if you're running them at somewhere around 40-50w. I would go so far as to say 1 cob centered over 1 plant, meaning regular small size plants, obviously not ones veged for months. Like say 9 COBs in a 3'x3' space and 9 plants. Pretty much perfect. For PPFD you have to use conversion factors. You'd have to know how many lux at canopy height, which nobody knows but you, and convert that based on if the COBs are warm white or cool white.
nogod_
Well-Known Member
What is your priority? G/w or G/sqft?
If you don't really care about your electricity bill (sounds cheap where you are) then maximize your space.
You could hit 1200ppfd if your really want and pull the most weight out of your 5x5.
If g/w is what youre after then I wouldn't bother with a 42% efficient chip.
If you don't really care about your electricity bill (sounds cheap where you are) then maximize your space.
You could hit 1200ppfd if your really want and pull the most weight out of your 5x5.
If g/w is what youre after then I wouldn't bother with a 42% efficient chip.
we get raped on import. and i dont like waiting 30 days for parts i cant return if i have a problem. so that leaves mouser.ca
and digikey.ca and there prices up here are not so friendly. and going from hps/mh its pretty damn easy to save bank when power is 17.5 Kw/h. this is all just my 2cents so take it as such meaningless lol
and digikey.ca and there prices up here are not so friendly. and going from hps/mh its pretty damn easy to save bank when power is 17.5 Kw/h. this is all just my 2cents so take it as such meaningless lol
BobCajun
Well-Known Member
It's easy to have too much light with LEDs. With a little over 50w sq ft I would always get bleaching. I had to put a dimmer on it. I seriously think anything over about 40w sq ft is excessive, at least if you have an enclosed space with reflective sides and not much vertical space to raise the light. The plants don't actually burn and get brown and dry like with too much HPS, but they turn very light green/yellow and look like hell.
buddss
Member
Hey Rahz, im sorry to dig out this old post of yours. But please tell me where you've got this data from. I'm a little bit dissapointed about the informations from bridgelux. on the official datasheet there is no word about umol/j and PPF. please tell me
ps.
Please explain how you get from umol/j to PPF. i'm not getting that..
cheers
Rahz
Well-Known Member
Hi buddss,
The efficiency and umol/j figures are derived from the spectral graphs in the datasheets. 4.65/4.66 is common knowledge for the 3500K 80CRI Vero V2/g5 chips though I don't remember who provided the figure. If you're interested in deriving the data for other chips you can see how it's done here: https://www.rollitup.org/t/math-behind.868988/
PPF is simply umol/j x PAR watts, PAR watts = output watts x efficiency.
The efficiency and umol/j figures are derived from the spectral graphs in the datasheets. 4.65/4.66 is common knowledge for the 3500K 80CRI Vero V2/g5 chips though I don't remember who provided the figure. If you're interested in deriving the data for other chips you can see how it's done here: https://www.rollitup.org/t/math-behind.868988/
PPF is simply umol/j x PAR watts, PAR watts = output watts x efficiency.
buddss
Member
ah you're the guy from tastyled? found that website one time. very good product indeed, i think i talk to the right person
thanks for the explanation!
PilouPilou
Well-Known Member
Hi @Rahz.. so for a CXB3590 3500K CD @1400mA it's 48.85W x 56.34%=27.52 PAR Watts ?
Rahz
Well-Known Member
Yes that's right.
Photon Flinger
Well-Known Member
We should all agree to toss that out the window and test in environment for PPFD.
Yes I know you vendors have a pitch for PPF but I have found so much variance with the margins of error between planning and actual that it isn't worth the guess.
Rahz
Well-Known Member
It's not the whole story but it's useful for vendors because it's Bridgelux/Cree/Citizen data and anyone can check our math with that data. I also like par maps but always look for 3rd party data rather than vendor data.
NoFucks2Give
Well-Known Member
Except PPF is a completely useless metric for LEDs. If a LED grow light vendor uses it, that vendor is useless to me. I only want to know how many photon reach the leaves for how many $$$. PPF is useless and generally used by charlatan vendors to deceive those that do not understand the difference between PPF and PPFD. PPF is okay for light bulbs, NOT LEDs.
Rahz
Well-Known Member
Not many charlatan vendors list PPF but I've seen vendors list a spot reading and suggest it's PPFD. PPF is not the same as lumens so I don't know why you would say it's okay for lightbulbs. Umol/j has become a pretty standard way of quantifying light output across various sources for horticultural use. Par wattage is also useful.
NoFucks2Give
Well-Known Member
PPF like Lux is an isotropic measurement. Light bulbs are an isotropic light source. CoBs and SMT LEDs are not isotropic.
The biggest problem with PPF and PPFD is they are NOT standards. µmol/J is an ambivalent measurement. It does not indicate how the µMoles were measured due to lack of standards.
Watts are not applicable to horticulture.
Blue and Green photons have more Watts than Red.
A Watt of Red photons has more photons than a Watt of Blue or Green photons.
If you used Radiometric Watts to compare a 6000K and 2000K LED light source with the same PPF, it would significantly favor the 6000K.
No such thing as PAR Watts. It is a term used to distort the figures.
You have
- Radiant Flux measured in Watts
- Radiant Intensity measured in Watts / steradian
- Irradiance measured in Watts / m²
- Radiance measured in Watts / m² / steradian
So if you really wanted to express a light source in Watts and PAR the proper term would be PAR Radiant Flux.
And Lumens? Lumens should NEVER be used in horticulture.
Rahz
Well-Known Member
PPF is an absolute value and is quite useful despite your protests. Whether the source is isotropic is irrelevant.
It's the 3rd party data I have access to... based on emitter manufacturer sphere and spectrometer results.
Par watts doesn't take spectrum into account but it's still radiant watts in the 400-700nm range. Again, useful despite your protests. Not perfect but it doesn't need to be.
Did I mention lumens for plants?
It's the 3rd party data I have access to... based on emitter manufacturer sphere and spectrometer results.
Par watts doesn't take spectrum into account but it's still radiant watts in the 400-700nm range. Again, useful despite your protests. Not perfect but it doesn't need to be.
Did I mention lumens for plants?
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PilouPilou
Well-Known Member
Hi!
I ask here because it talks about VERO chips.
I want to use VERO29C SE version.. 3 in serie with the 320H-1400mA, is it good? I read here that they can support until 500V but I don't find documents in the website of BX talking about the max Voltage of the connector SE version. Thanks.
I ask here because it talks about VERO chips.
I want to use VERO29C SE version.. 3 in serie with the 320H-1400mA, is it good? I read here that they can support until 500V but I don't find documents in the website of BX talking about the max Voltage of the connector SE version. Thanks.
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NoFucks2Give
Well-Known Member
l
Measuring the radiant exitance (flux density / PPF) is of little use. Radiance, Luminance, and PPF are the measure of exitance flux density per unit solid viewing angle an independent of distance because the sampled area increases with distance canceling the inverse square loss.
Whereas the radiant intensity (e.g. PPFD) is the measure of the radiometric power incident a surface per unit solid angle (W/sr) related to irradiance by the inverse square law. Distance, angle, and position are relevant for horticulture applications.
When you are using an instrument designed to measure an isotropic light source, to measure a non-isotropic light source, it is relevant.
When the light source is used in a direct line of sight, how is a integrating sphere measurement of scattered, reflected, and diffused light going to matter? In a sphere the light source is baffled from the detector to block direct light.
You can use a Point Source Approximation but using the proper measuring instrument for the application is preferable.
An integrating sphere removes all positional, directional and uniformity from its measurements. This may be useful for lighting applications but not applicable to horticulture which uses direct light. In horticulture it is only useful to measure the flux from a source as it is emitted in a given beam.
One watt @ 680nm = 5.68 µmol
One watt @ 420nm = 3.51 µmol
"there is a difference between total radiant flux collected and useful radiant flux collected" - Newport Corp. Spectral Irradiance training manual
Measuring the radiant exitance (flux density / PPF) is of little use. Radiance, Luminance, and PPF are the measure of exitance flux density per unit solid viewing angle an independent of distance because the sampled area increases with distance canceling the inverse square loss.
Whereas the radiant intensity (e.g. PPFD) is the measure of the radiometric power incident a surface per unit solid angle (W/sr) related to irradiance by the inverse square law. Distance, angle, and position are relevant for horticulture applications.
When you are using an instrument designed to measure an isotropic light source, to measure a non-isotropic light source, it is relevant.
When the light source is used in a direct line of sight, how is a integrating sphere measurement of scattered, reflected, and diffused light going to matter? In a sphere the light source is baffled from the detector to block direct light.
You can use a Point Source Approximation but using the proper measuring instrument for the application is preferable.
While PPF is an absolute measurement..
...I fail to see how PPF is "useful" or relevant to horticulture applications or how 3rd party data can be applicable to PPF.
An integrating sphere removes all positional, directional and uniformity from its measurements. This may be useful for lighting applications but not applicable to horticulture which uses direct light. In horticulture it is only useful to measure the flux from a source as it is emitted in a given beam.
One watt of deep red can have 50% more photons than a watt of deep blue.
One watt @ 680nm = 5.68 µmol
One watt @ 420nm = 3.51 µmol
Rahz
Well-Known Member
(and the rest)
Optical considerations. It doesn't invalidate the usefulness of knowing the photon count being emitted from the source.
Yes and said that way it makes a big difference, but from one white light to another the difference won't be so great. Any white light at 5 par watts per foot is going to be weak. Any white light at 25 par watts per foot is going to be very intense. It's a much more accurate way to go about things than just watts per foot, or lumens.
The main point I've been trying to make is that anyone, knowing the parts used, can calculate par watts and PPF. Not only are they reasonable numbers to base a system on (I don't know why you insist they aren't) they are also reasonable numbers for comparison and don't require faith that every vendor takes fair measurements.
NoFucks2Give
Well-Known Member
I do not know where you get these "PAR Watts" and PPF values.
Anything derived from lumens, watts, or lm/W is of no interest to me.
When looking at a datasheet I am most interested in spectral power distribution, then thermal characteristics, then radiation pattern.
Then I get a sample and measure it with a radiospectrometer.
Anything derived from lumens, watts, or lm/W is of no interest to me.
When looking at a datasheet I am most interested in spectral power distribution, then thermal characteristics, then radiation pattern.
Then I get a sample and measure it with a radiospectrometer.