Input Needed For Experiment Comparing Cob Led To Hps De

[cccmints]

I'm purchasing a lux meter to observe the CXB3590 (CD) 3500K & Vero SE 29 Gen 7 (D) 3500K @ 1.75 amps. The results of this observation will be used for a 12 COB fixture design. I'll likely test more COBs, and these same COBs, at different currents after these two have been tested @ 1.75a. Any other COBs you'd like to suggest for testing I'll consider purchasing as well.

For now these will be my options:
[CXB3590] 36 x 1.75 = 63 Watts || 756 Watt Fixture
[Vero 29] 36.6 x 1.75 = 64.05 Watts || 768.6 Watt Fixture

Once I've built my fixture, I want to run, document, and present a proper experiment comparing COB LED to 1000w HPS DE, with LED running @ 20-25% less power draw. The problem is, even the HPS guys agree HPS is not ideal for vegetative growth. I don't want to appear bias towards LED by using HPS for veg. After all, the big question we all have right now is; Can LED hang with HPS during the flowering stage?

I'd love some input on this while I wait for the lux meter, COBs, and driver to come in. I can't grow cannabis right now, so I'm looking for a plant which has similar growth characteristics to marijuana. I'm considering Sunn Hemp, Electric Daisy, Spider flowers, Cranberry Hibiscus, etc.

Here's a link to the page I got these ideas from:
https://www.greenrushdaily.com/legal-plants-similar-cannabis/

For the experiment, since I'm choosing to test LED with a kelvin temp suitable to full-cycle growth, should I veg the HPS plants alongside the LED plants in the same tent during veg and then transfer the HPS plants to their own tent under the 1000w HPS DE light for flowering once its time to switch the photoperiod to 12/12?

 

[sixstring]

your numbers for vero will prob be around 800w or more from the wall with a good meanwell driver.those veros at 1.75 amp will be around 37.5 to 38v i think so closer to 66w per cob x 12 =792w plus driver losses prob around 820w at the wall if i had to guess.still saving over 200w at the wall and this fixture should have a sizable increase in par in a 4 x 4 or 5 x 5 area. i would use hemp over any fruit/veggie/shrub/flower if you want a good idea of how marijuana will respond.

 

[MW7945]

Lux is pretty irrelevant to be honest. What you're looking for is PAR/PPFD

 

[cccmints]

your numbers for vero will prob be around 800w or more from the wall with a good meanwell driver.those veros at 1.75 amp will be around 37.5 to 38v i think so closer to 66w per cob x 12 =792w plus driver losses prob around 820w at the wall if i had to guess.still saving over 200w at the wall and this fixture should have a sizable increase in par in a 4 x 4 or 5 x 5 area. i would use hemp over any fruit/veggie/shrub/flower if you want a good idea of how marijuana will respond.

I have noticed the COB datasheets display a range for the forward voltage of their COB, but the wholesalers of these COBs only advertise a fixed voltage. How do I determine where in the range I fall @ the current I'm aiming to drive? I will probably use hemp, thanks for the suggestion.

Lux is pretty irrelevant to be honest. What you're looking for is PAR/PPFD

You can convert Lux to PAR. I even have a calculator that does it for me. Its best to buy a Lux meter because you really don't even need a PAR meter if you can observe the lux output of whatever light source you're observing.

 

[MW7945]

I mean, you can try to convert lux to par. But it won't be very accurate.

 

[cccmints]

I mean, you can try to convert lux to par. But it won't be very accurate.

Why do you say that? I'm not opposed to buying a PAR meter in addition to the Lux meter. Its just I've just seen people online do the conversion and I have a calculator which uses various inputs (one being nominal flux) to determine the PAR without having a PAR meter.

I figured I could save a bit by just getting the lux meter and using the calculator to determine PAR/PPFD. A PAR meter would probably be good for observing light degradation though, so I'll probably just buy one of those too.

 

[MW7945]

You can get a rough idea what the PAR is from lux, but there's a lot of variables. You're essentially counting apples to guess how many oranges you have when you go that route

 

[cccmints]

You can get a rough idea what the PAR is from lux, but there's a lot of variables. You're essentially counting apples to guess how many oranges you have when you go that route

Alright, I see what you're saying, thanks. So a PAR meter will be added to the list of things to order today.

To be ordered today:
-(1x) CXB3590 (CD) 80 CRI 3500K
-(1x) Vero 29 Gen 7 80 CRi 3500K
-(1x) CXM-22 Gen 3 80 CRI 3500K
-(3x) FN14074 Reflectors
-(3x) SSTX Splayed Fin Heatsinks
-(1x) 1.7 Amperage 80 Watt Meanwell Driver (Used for CXB3590 & Vero 29 separately)
-(1x) 1.21 Amperage 65.3 Watt Meanwell Driver (Used for CXM-22)
-(1x) PAR Meter
-(1x) Lux Meter

Hopefully @sixstring can help me understand how the forward voltage of COBs change dependent upon the driver you use. @ the numbers advertised by digikey the CXM-22 has a FV of 51v so 51v x 1.21a = 61.71 Watts || 740.52 Watts (12 COB Fixture)

 

[MW7945]

Tbh, I don't know that you'd need a PAR meter right away, but I suppose if you're purely doing this for testing it'd only make the most sense. I do have the hydrofarm par meter and my only complain is that the battery life sucks. But, it's rechargable

 

[cccmints]

Tbh, I don't know that you'd need a PAR meter right away, but I suppose if you're purely doing this for testing it'd only make the most sense. I do have the hydrofarm par meter and my only complain is that the battery life sucks. But, it's rechargable

Well the next thing I'm doing is building out a 12 COB fixture and purchasing the components for a "High-End HPS" fixture then running them in separate tents over what I suppose will be a yet to be determined strain of hemp. I need the lux meter to test the COBs individually for my 12 COB fixture design before running the side-by-side experiment, but I will then need a PAR meter to measure HPS' light degradation vs LED's light degradation.

I'm sure the quality to price ratio is similar for PAR meters as it is for Lux meters. For Lux meters, >= $200 and you get >= 3% accuracy. When you jump into the $1,000 range you get a mere 0.5% increase in accuracy (>= 2.5%).

I can have a nice Lux meter and PAR meter for around $400 which is fine with me. I'll just grab both right away.

 

[sixstring]

citi 1818

cree 3590

vero 29 37.8 v or whatever lol

you may like this nifty chart as well from supraspl

pay no attention to prices as things have come down since any of these were made.

 

[gwheels]

I am looking forward to seeing how it works out. My curiosity is piqued. All we need is 2 X 315 CMH to compare with that and we will have a winner! Or at least prove that the lights are better at flower or trich development or whatever. I am subbed.

 

[jumpincactus]

Lux is pretty irrelevant to be honest. What you're looking for is PAR/PPFD

indeed..... lux and lumens are irrelevant ..... Lumens is for humans and play no part or lux in what a plant needs.

You need a good quantum meter to measure ppfd as what matters most no matter what lighting you use is the actual amount of photons hitting the leaves. There is a conversion you can use to roughly calculate your ppd/ppfd with a lux meter. I will see if I can dig it up.

Also keep in mind figuring your ppfd with LED tech isnt as easy as it is with standard legacy HID lighting,

http://www.horticoled.com/en/lumens-lux-candelas-par-ppf-ppfd-dli/

Here you can find the conversion factors https://www.apogeeinstruments.com/conversion-ppf-to-lux/

 

[jumpincactus]

Article on LED and factoring what its light output is http://ledgardener.com/lumens-par-ppf-and-ppfd-measuring-cob-grow-light-output/

 

[jumpincactus]

http://ledgardener.com/compare-different-cob-leds/

 

[cccmints]

Sweet, thanks @sixstring So it appears the harder you drive the COB, the higher its Forward Voltage. 1.75a isn't listed in that data, so I'll be able to fill in that gap with this test. I think a 12 COB fixture pushing the Vero 29 @ 1.75a would prove to be fantastic. Time will tell...

@gwheels I'm doing HPS first since its currently the most popular alternative to LED. I plan to also compare the fixtures I build to quantum boards, CMH, etc. in the future.

@jumpincactus The reason for me wanting to collect the lux is because its a variable for the calculator I'm using. The calculator requires you to digitize the spectral distribution of the COB you're testing, input the forward voltage, drive current, flux @ drive current %, and finally, the nominal flux. With this, the calculator produces the QER (umol/W/s), LER (lm/W), Efficiency (%), PAR (W), PPF (umol/s) of that COB @ whichever drive current you're testing.

Any ideas as to why Nominal Flux is part of this calculator? Remember guys, I'm new to all of this, but I'm dedicated to designing a great match for the 1000W DE HPS while drawing way less power and reaping the benefits LED brings overall.

Maybe the Nominal Flux is needed to produce the figures that calculator gives upon inputting the above listed variables, meaning I still need a Lux meter? It seems I definitely need a quantum sensor, so that's been added to the price list. I'd like to order this equipment today if possible but will obviously wait until I'm sure I'm getting what I need to run the tests/experiments I aim to provide for the community.

Thanks for all the input gentlemen. Lets figure this out together!

 

[brazel]

How good would the data be if you're not getting it correctly you're converting it so right there I would say your experiment is void.
If you're going to buy a light for growing and they talk about Lux or lumen I would instantly avoid it
Cheers

 

[cccmints]

How good would the data be if you're not getting it correctly you're converting it so right there I would say your experiment is void.
If you're going to buy a light for growing and they talk about Lux or lumen I would instantly avoid it
Cheers

I said I'd be purchasing a quantum sensor and am questioning purchasing a lux meter in addition to that for the sole purpose of filling the input this calculator requires. Maybe the nominal flux is used to determine the value of one of the other variables this calculator has in addition to PAR (which I'd have a quantum sensor for).

I'm definitely getting a quantum sensor, and may get both. The experiment will not be void.

 

[brazel]

Ok, so lux is irrelevant correct? You get this right, so if you need Lux to get calculations out of a calculator do you really think that's something you need because Lux is irrelevant, remember? That's like taking the letter M and try to divide it by 7 it's not going to happen cuz one of them is irrelevant.
Listen bro I don't have anything against you I'm trying to be for you by helping you out.
I'm not trying to put you off or tell you not to do it or be rude or anything that.
When talking about plant growth there is absolutely zero reason you would ever want to say the word Lux let alone have a lux meter.

Where did you even get the information that lux is what you need?

You said any info would be liked or something like that but either way you haven't took anybody's advice? Almost every post has no to lux but you keep saying lux!?
It does matter if you use a book of matches, a bic lighter, cob, cmh, whatever other light source...it doesn't matter!
The best piece of advice I can give you in this situation is drop the word Lux from your vocabulary unless you're are curious about the light you see or you're not doing an experiment or you're a home grower!

Does it measure light, yes! But not like it should!
Switch that word with ppf learn how efficient your lights are at par.
Photon efficacy, read about that
Ppfd take measurements all over the light pattern.

And I know people might say I'm being rude or something like that but did you ever go to college cuz it's how your professors will teach you it's not kindergarten anymore

That's like me trying to buy a house by going umbrella shopping! That's extreme but still you cannot do an experiment and have any actual facts based on stuff that's irrelevant.period. case closed. End of discussion.
Good luck and cheers!

 

[cccmints]

Ok, so lux is irrelevant correct? You get this right, so if you need Lux to get calculations out of a calculator do you really think that's something you need because Lux is irrelevant, remember? That's like taking the letter M and try to divide it by 7 it's not going to happen cuz one of them is irrelevant.
Listen bro I don't have anything against you I'm trying to be for you by helping you out.
I'm not trying to put you off or tell you not to do it or be rude or anything that.
When talking about plant growth there is absolutely zero reason you would ever want to say the word Lux let alone have a lux meter.

Where did you even get the information that lux is what you need?

You said any info would be liked or something like that but either way you haven't took anybody's advice? Almost every post has no to lux but you keep saying lux!?
It does matter if you use a book of matches, a bic lighter, cob, cmh, whatever other light source...it doesn't matter!
The best piece of advice I can give you in this situation is drop the word Lux from your vocabulary unless you're are curious about the light you see or you're not doing an experiment or you're a home grower!

Does it measure light, yes! But not like it should!
Switch that word with ppf learn how efficient your lights are at par.
Photon efficacy, read about that
Ppfd take measurements all over the light pattern.

And I know people might say I'm being rude or something like that but did you ever go to college cuz it's how your professors will teach you it's not kindergarten anymore

That's like me trying to buy a house by going umbrella shopping! That's extreme but still you cannot do an experiment and have any actual facts based on stuff that's irrelevant.period. case closed. End of discussion.
Good luck and cheers!

No, I don't see how you could surmise from my post that lux is irrelevant. PAR is directly connected to the flux output of the COB, which is why its showcased in their datasheets. Just because plants don't utilize the total flux output of a COB LED diode, doesn't render a lux meter useless. I'm not just trying to understand plant growth underneath these fixtures, I'm trying to use this COB technology to create an ideal light fixture as a replacement for HPS.

I will say though, the tone of your post is unnecessary, and if you want my honest opinion, it doesn't look good on you. You clearly haven't even read the entire thread because you're asking questions which have already been answered. Try reading the thread before making a post next time, or try reading this thread and post a useful response.

Your analogies are horrendous. Lux is not irrelevant to the performance of COBs. THAT is an actual fact. This is FAR from the end of this discussion. The idea that you think you can end the discussion with what you've posted is comical.

Good luck and cheers to you!