Initial price yes, efficiency no. Running at the low currents they need to be competitive with Cree, I don't want to sacrafice light penetration. 56% at 1400ma isn't bad at all.
Introducing CobKits.com - specializing in DIY and Citizen COBs
CobKits
Well-Known Member
id take a higher number of fixtures for 'penetration' personally. even one additional 1212 would make up for the few percentage points in efficiency, for a chip that costs 1/3 as much
4000K:
1212 at 12", 1400 mA=451 PPFD
3590 at 12", 1400 mA=463 PPFD
3000K:
1212 at 12", 1400 mA=369 PPFD
3590 at 12", 1400 mA=391 PPFD
4000K:
1212 at 12", 1400 mA=451 PPFD
3590 at 12", 1400 mA=463 PPFD
3000K:
1212 at 12", 1400 mA=369 PPFD
3590 at 12", 1400 mA=391 PPFD
Yes but that 1/3 as much will come back in electricity savings in just a couple grows I would imagine.
How do you calculate PPFD cause I'm doing something wrong apparently.
Abiqua
Well-Known Member
How do you calculate ppf?
CobKits
Well-Known Member
ppf = watts x QER i beleive
possibly... if no other factors are limiting. youre talking a few percent in efficiency vs paying 3 times more for chips
Victor6634
Well-Known Member
So in newb terms it's ppf divided by meters squared ?
No different than buying a more expensive binned chip isn't it?
Price
4 Citizen 1212's $44
4 CXB3590's $120
Difference of $76
Efficiency
Citizen 45%
Cree 56%
Difference let's say 10%
If my bill from the LED setup is about $30, I'll save a measly $3 a month. A grow is roughly 4 months long?
I'll save $12 for every grow. I would need 6 grows before these break even.
Looks like you're right. Sorry, I just needed to see this in numbers. I'm back on board the Citizen train it looks like.
Where is the cheapest place for pre drilled & tapped Citizen CLU048 pin fin heatsinks?
Looking to run 6-8 of the 1212's at 1400ma now.
CobKits
Well-Known Member
except those are completely pulled out of the air and its closer to 2-5% at 1400 mA
I got my numbers from some charts on this post here:
https://www.rollitup.org/t/cheap-and-cheerful-diy-using-citizen-cobs.909460/page-13
Post 250
Abiqua
Well-Known Member
umol/s ....I believe the spectrum has to be digitized to get this number? It isn't in any datasheet I am aware of...past umol/s for Various chips are posted somewheres....who will chime in...
@alesh...can you explain calculating PPF a little Further?
also
QER will give you PAR watts emitted but joules per umol is how to calculate umol/s.
Calculating PPF
PPF /nm = (10-3) * [λ Φ(λ)] / (Nahc),
where:
Na = Avogadro's constant, 6.022 x1023
h = Planck's constant (6.626 x 10-34 joule-seconds)
c = speed of light, 2.998 x 108 m/s
λ = wavelength in meters.
http://docs.agi32.com/AGi32/Content/adding_calculation_points/PPFD_Concepts.htm
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Abiqua
Well-Known Member
Which Cree Kelvin temp? 3, 35, 4?
3500k. I believe this is the best all purpose temp?
This shit just went way over my head LOL.umol/s ....I believe the spectrum has to be digitized to get this number? It isn't in any datasheet I am aware of...past umol/s for Various chips are posted somewheres....who will chime in...
@alesh...can you explain calculating PPF a little Further?
also
QER will give you PAR watts emitted but joules per umol is how to calculate umol/s.
Calculating PPF
PPF /nm = (10-3) * [λ Φ(λ)] / (Nahc),
where:
Na = Avogadro's constant, 6.022 x1023
h = Planck's constant (6.626 x 10-34 joule-seconds)
c = speed of light, 2.998 x 108 m/s
λ = wavelength in meters.
http://docs.agi32.com/AGi32/Content/adding_calculation_points/PPFD_Concepts.htm
I'll give it another look in the morning. I appreciate how I'm depth you're going
Abiqua
Well-Known Member
So the joules per umol on the 3500k 80 cri is 4.65.
I have 3500K 3070's Cree CXB BB bins.....so lets use that example to calculate an example PPF....
1x 3500 @ 1050 mA = 36.45 Dissipated Watts the Qer is 324 so efficieny is 54.21% @ 175.66 L/watt [175.66/324 = 54.21]
PAR watts = 19.75 [36.45 Wdiss * 54.21%]
PPF = 91.8 [19.75 PAR w * 4.65 joules/umol for a 3500K Cree]
whole nother "can o' worms" question. But a fine choice. I tend to think along the lines of strain dependency, but everyone has a different grow and response.
I run a perp setup with 4k, 35k and 3k to finish in the final weeks. I like the results across a wide variety. I want to try a year of 3500k and 2700k together, before I make anymore claims.
Indica if it makes a difference. So much good info I'm getting today
Bedtime for me today. Hopefully this weekend I can put everything together and get a final price for the build and order. Bedtime now
HolyGhost23
Well-Known Member
I live in northren canada.. i could probably run a cob glued to a tile in the winter..gets down to -40C.
HolyGhost23
Well-Known Member
cobkits.com. how much could would be for you to get me a 185-54. don't care on model so long as it does 54 volts and around 185 watts..
if you already answered this sorry.. this thread gets more posts than a live nude cam of amanda bines
if you already answered this sorry.. this thread gets more posts than a live nude cam of amanda bines