easy answer, Citi or cob calculator. Long answer Use the Luminous 22 at Cobkits for the best light spread option. closest thing I have is the 1818... still deciding on CRI. Thinking the 70 will provide a bit more red but I would rather have less stretch... choices.. Hope you like wiring.
1818 3500K80Min 48 COBS @400 mA ON 4.85 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 991.43
Cobs power watts: 931.94
Total voltage forward: 2329.85
Total lumens: 161191.49
Total PAR watts assuming 10% loss: 433.05
Total PPF: 2314.42
PPFD based on canopy area: 1557.01
PAR watts per sq.ft.: 27.07
Cob efficiency: 51.63%
Power watts per sq.ft.: 58.25
Voltage forward per cob: 48.54
Lumens per watt: 172.96
Heatsink riser thickness / number of fins / fin's length: 0.14in/16/0.66in
Heatsink area per inch: 200.6 cm^2
Total heat watts: 447.33
umol/s/W: 2.48 LER: 335.00 QER: 4.81
Heatsink length passive cooling @120cm^2/heatwatt: 268 inches
Heatsink length active cooling @40cm^2/heatwatt: 89 inches
COB cost dollar per PAR watt: $2.55
Electric cost
@12/12 in 30 days: $53.54
Electric cost @18/6 in 30 days: $80.31
Cost per cob: $23.0
Heatsink cost per inch cut: $0.98
Total cobs cost: $1104.0
Total heatsink passive cooling cost: $262.64
Total heatsink active cooling cost: $87.22
1818 3000K70Min 48 COBS @400 mA ON 4.85 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 991.43
Cobs power watts: 931.94
Total voltage forward: 2329.85
Total lumens: 166923.15
Total PAR watts assuming 10% loss: 458.02
Total PPF: 2473.31
PPFD based on canopy area: 1663.91
PAR watts per sq.ft.: 28.63
Cob efficiency: 54.61%
Power watts per sq.ft.: 58.25
Voltage forward per cob: 48.54
Lumens per watt: 179.11
Heatsink riser thickness / number of fins / fin's length: 0.14in/16/0.66in
Heatsink area per inch: 200.6 cm^2
Total heat watts: 419.37
umol/s/W: 2.65 LER: 328.00 QER: 4.86
Heatsink length passive cooling @120cm^2/heatwatt: 251 inches
Heatsink length active cooling @40cm^2/heatwatt: 84 inches
COB cost dollar per PAR watt: $2.41
Electric cost
@12/12 in 30 days: $53.54
Electric cost @18/6 in 30 days: $80.31
Cost per cob: $23.0
Heatsink cost per inch cut: $0.98
Total cobs cost: $1104.0
Total heatsink passive cooling cost: $245.98
Total heatsink active cooling cost: $82.32