Quantum Board QB 288 V2

CobKits said:
my main metric i should say. i run in tenets and dont use reflectors on my cobs. mid power diodes throw light at same angle
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Yes, but then it matters a lot if they are 18" up above the canopy vs 8" to 10".

If you see ledgardners PPFD matrices he ends up with an average PPFD for boards which is only 60% of what you would expect based on the light produced. From 950PPF (extrapolated to 1m2) to 550umol/s/m2 average PPFD over a 2'x2' floor. Or in other words, that 2.5umol/s/W efficacy ends up as 1.4umol/s/W on the plants.

Of course with bigger grow areas the wall losses will be less, but still.
 
that sounds odd. maybe in an open area

flat white paint is over 90% reflective. And many people use better than that for their walls. of course getting the light on the plants is of primary importance Kinda reminds me of when cree's "reference design" (which was ok but not all that) claimed to match a gavita with half the wattage... and it was all how they measured the light

quantifying different light techs is difficult without a goniophotometer or a 2m sphere. I was going to run another series of tests with current boards and cobs using this setup:

https://www.rollitup.org/t/par-test-of-cobs-vs-samsung-561-boards.942636/

@wietefras @ledgardener id love to hear critiques on this ad-hoc method and how i could improve it

basically it is setup to account for the different throw of cobs and midpowers by being far enough away that the light is predominantly uniform and reflected (sort of like in a sphere where there is a baffle to make it all reflected light). In this case we do ahve direct light but again its pretty far away, that angle of incidence doesnt really matter. You can see in post 12 of that thread that all the measurements on the floor of the tent are within 5% of each other for both boards and cobs.

this doesnt really address your light throw comment, as its intended as a gross output/efficiency measurement. but i agree if you are wasting light cobs are much more easy to use reflectors with.
 
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CobKits said:
that sounds odd. maybe in an open area
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No, in a tent. Look it up on his Youtube channel if you don't believe me. It's a white poly tent though. So indeed not the best reflection probably.

Still, when I run it in the simulator with better reflective walls I see similar results.

flat white paint is over 90% reflective.
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Nah, that's just a myth. It's 70% at best (when it's pristine). Besides it reflects light in all directions (diffuse) which means a lot will bounces back towards the ceiling and lamp.

https://www.rollitup.org/t/par-test-of-cobs-vs-samsung-561-boards.942636/

id love to hear critiques on this ad-hoc method and how i could improve it
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It doesn't make sense to give the COBs the same handicap as the boards have. That's the whole point of having COBs (or even better, led strips) spread out over the surface.

Sue you can get the same efficacy of the fixture, but the point that is missed is that there is a lot of light lost due to the concentrated nature of these fixtures.

Boards need to be at 18" while a single row led strip fixture would be fine at 4" even for good uniformity. There is a huge difference in wall losses then.
 
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that would be a different test. i was just looking at gross efficacy

also im in a tent so thats fine for my purposes imo. my cobs are 12-18" off top of canopy
wietefras said:
No, in a tent. Look it up on his Youtube channel if you don't believe me.
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not being lazy (ok im being lazy) but can you link it here for others
 
Well, I'm lazy too :)

Dropping those COBs lower would decrease wall losses. 10" lower can easily give you 20% to 25% more light on the plants (or you could dim the lights and keep the intensity the same)
 
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I like the HLG 600 but I don't like the shape very much. Why can't they make these things more square-like instead of rectangular? Wouldn't the light spread better for a 4 x 4 tent?
 
wietefras said:
Nah, that's just a myth. It's 70% at best (when it's pristine). Besides it reflects light in all directions (diffuse) which means a lot will bounces back towards the ceiling and lamp.
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False, I have looked at data from behr, Ben Moore, and a few others that advertise between 83% and 94% reflectivity for flat white. You are correct about the light diffusion though.

I just assembled an HLG600 and the thing is great, although I’m pulling about 64-65c on the top of the panels with power all the way up. That’s acceptable, correct?
 
M0e b1unt5 said:
False, I have looked at data from behr, Ben Moore, and a few others that advertise between 83% and 94% reflectivity for flat white. You are correct about the light diffusion though.
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Flat white paint with Barium perhaps and only when just applied and a lot less after a few grows. You'd be lucky to get even 70% with latex or something (plus much of the light going away from the plants too).

Just see the matrix measuremens ledgardner did where more than 40% of the light coming from a quantum board in a white poly tent had been eaten by the walls.
 
Hot Diggity Sog said:
This is the driver guide I was looking at:
https://horticulturelightinggroup.com/pages/qb288-board-guide

So many options.

Would you guys suggest running 2 of the QB288 dual combo kits on 1 driver or find one driver that could run 4 of these kits.

  • HLG-240H-C2100 - 2 Boards in series
  • HLG-240H-C1050 - 4 Boards in series
Suggestions? I'm an LED noob so just looking for guidance.
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I would say no if you have to ask the question it's probably not safe to be playing with the amount of volts and amps a big driver has stick with the 240h c1050 you won't be killing yourself with that.


Edit: if your set on the 1 driver an hlg 600h would be good
 
Hot Diggity Sog said:
I just ordered two QB288 V2 combo kits...these:
https://horticulturelightinggroup.com/collections/all/products/qb288-v2-slate-2-double-combo

I got a 3000K and a 4000K. I will likely be purchasing two more.

Can you guys advise me on what driver I should get...the options are a bit overwhelming.
I'm currently leaning towards running them at 1100mA.

One driver for 2 of these kits?
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The hlg-240h-c2100a is what is sent out with the kits, they work well.
The A version of the driver allows it to be ran at about 2.44A so you will be getting the full 250w
If you need help wiring them, post back and I can post a diagram. It's extremely simple and takes maybe 15-20 mins for someone who hasn't done it before.
 
Aolelon said:
The hlg-240h-c2100a is what is sent out with the kits, they work well.
The A version of the driver allows it to be ran at about 2.44A so you will be getting the full 250w
If you need help wiring them, post back and I can post a diagram. It's extremely simple and takes maybe 15-20 mins for someone who hasn't done it before.
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Just something I've been wondering about, why can't you get them to do 300w?
 
Frank Nitty said:
Just something I've been wondering about, why can't you get them to do 300w?
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That driver does hit about 300w maxed out I have 3 of them wired to 1 outlet it reads over 900w i accidentally ran it that high for like a month it didn't cause any problems each driver is on a slate 1 triple heatsink with 3 304 QB I run it around 700w now that I have a watt meter it got pretty damn hot at max power
 
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