So I guess I'm kinda going at this backwards then. I started with what layout I want 3x3 cob. Then I broke down the power from the wall I wanted use. Max 650w. Then i tried to make it as efficient and moderately priced from the calculators.
When you say that you would need 71 of the 1212 vs 48 to equal the same 1818's, in what measurement are you referring
This is what I was referring to using my area and the 2 different cobs The number I am looking at is PPFD
Citizen.1212C4.3000K 71 COBS @1.4A ON 5.88 PROFILE HEATSINK
96 SQ.FT. CANOPY 93% EFFICIENT DRIVER @10 CENTS PER KWH
Total power watts at the wall: 3858.06
Cobs power watts: 3588
Total voltage forward: 2563
Total lumens: 523848
Total PAR watts assuming 10% loss: 1437
Total PPF: 6983.82
PPFD based on canopy area: 783.05
<<<<<<This number here
PAR watts per sq.ft.: 14.97
Cob efficiency: 44.51%
Power watts per sq.ft.: 37.38
Voltage forward per cob: 36.1
Lumens per watt: 146.0
Heatsink riser thickness / number of fins / fin's length: 0.27in/14/1.0in
Heatsink area per inch: 260.01 cm^2
Total heat watts: 1991
umol/s/W / CRI: 4.86 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 919 inches
Heatsink length active cooling @40cm^2/heatwatt: 306 inches
COB cost dollar per PAR watt: $0.62
Electric cost
@12/12 in 30 days: $139.39
Electric cost @18/6 in 30 days: $208.84
Cost per cob: $12.55
Heatsink cost per inch cut: $1.74
Total cobs cost: $891
Total heatsink passive cooling cost: $1599
Total heatsink active cooling cost: $532
Citizen.1818C4.3000K 48 COBS @1.4A ON 5.88 PROFILE HEATSINK
96 SQ.FT. CANOPY 93% EFFICIENT DRIVER @10 CENTS PER KWH
Total power watts at the wall: 3756.99
Cobs power watts: 3494
Total voltage forward: 2496
Total lumens: 520606
Total PAR watts assuming 10% loss: 1430
Total PPF: 6949.8
PPFD based on canopy area: 779.24
<<<<<<< here a few points difference less than 4ppfd
PAR watts per sq.ft.: 14.9
Cob efficiency: 45.48%
Power watts per sq.ft.: 36.4
Voltage forward per cob: 52.0
Lumens per watt: 149.0
Heatsink riser thickness / number of fins / fin's length: 0.27in/14/1.0in
Heatsink area per inch: 260.01 cm^2
Total heat watts: 1905
umol/s/W / CRI: 4.86 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 879 inches
Heatsink length active cooling @40cm^2/heatwatt: 293 inches
COB cost dollar per PAR watt: $1.08
Electric cost
@12/12 in 30 days: $135.75
Electric cost @18/6 in 30 days: $203.38
Cost per cob: $32.08
Heatsink cost per inch cut: $1.74
Total cobs cost: $1540
Total heatsink passive cooling cost: $1529
Total heatsink active cooling cost: $509