How to calculate PPFD for my build?

Joe34

Active Member
I am planning to get either

40 x Vero 29 3500k 80 CRI and run each at 50W per 1.25 sq ft - giving 192 Lumens per watt.
or
50 x Citizen 1212 3500k 80 CRI and run each at 45w per 1 sq ft - giving 160 Lumens per watt

total space for these is 5x10 ft, so 50 sq ft.

Would either of these builds provide a good enough PPFD?

I am not actually familiar with this measurment, in the past I have used HPS and never heard of it...

Could somebody post measurments for both of these builds

Many thanks!
 

visajoe1

Well-Known Member
Here is your data from calculator for citi's. Guessed on current, but 1050 seems to be good. PPFD right where you want it

1212 3500K80Min 50 COBS @1050 mA ON 1.813 PROFILE HEATSINK
50 SQ.FT. CANOPY 94% EFFICIENT DRIVER @13 CENTS PER KWH
Total power watts at the wall: 1916.78
Cobs power watts: 1801.78
Total voltage forward: 1715.98
Total lumens: 267810.06
Total PAR watts assuming 10% loss: 719.49
Total PPF: 3845.27
PPFD based on canopy area: 827.80
PAR watts per sq.ft.: 14.39
Cob efficiency: 44.37%
Power watts per sq.ft.: 36.04
Voltage forward per cob: 34.32
Lumens per watt: 148.64
Heatsink riser thickness / number of fins / fin's length: 0.3in/6/0.95in
Heatsink area per inch: 100.94 cm^2
Total heat watts: 1009.00
umol/s/W: 2.13 LER: 335.00 QER: 4.81
Heatsink length passive cooling @120cm^2/heatwatt: 1200 inches
Heatsink length active cooling @40cm^2/heatwatt: 400 inches
COB cost dollar per PAR watt: $0.83
Electric cost @12/12 in 30 days: $89.71
Electric cost @18/6 in 30 days: $134.56
Cost per cob: $12.0
Heatsink cost per inch cut: $0.66
Total cobs cost: $600.0
Total heatsink passive cooling cost: $792.00
Total heatsink active cooling cost: $264.00
 

visajoe1

Well-Known Member
Here is 40 cobs at 1400. Probably a better option, less cobs, less drivers, more PPFD

1212 3500K80Min 40 COBS @1400 mA ON 1.813 PROFILE HEATSINK
50 SQ.FT. CANOPY 94% EFFICIENT DRIVER @13 CENTS PER KWH
Total power watts at the wall: 2104.14
Cobs power watts: 1977.89
Total voltage forward: 1412.78
Total lumens: 277876.63
Total PAR watts assuming 10% loss: 746.53
Total PPF: 3989.81
PPFD based on canopy area: 858.92
PAR watts per sq.ft.: 14.93
Cob efficiency: 41.94%
Power watts per sq.ft.: 39.56
Voltage forward per cob: 35.32
Lumens per watt: 140.49
Heatsink riser thickness / number of fins / fin's length: 0.3in/6/0.95in
Heatsink area per inch: 100.94 cm^2
Total heat watts: 1147.18
umol/s/W: 2.02 LER: 335.00 QER: 4.81
Heatsink length passive cooling @120cm^2/heatwatt: 1364 inches
Heatsink length active cooling @40cm^2/heatwatt: 455 inches
COB cost dollar per PAR watt: $0.64
Electric cost @12/12 in 30 days: $98.47
Electric cost @18/6 in 30 days: $147.71
Cost per cob: $12.0
Heatsink cost per inch cut: $0.66
Total cobs cost: $480.0
Total heatsink passive cooling cost: $900.24
Total heatsink active cooling cost: $300.30
 

MeGaKiLlErMaN

Well-Known Member
Heres 50W per sq/ft, it would be a bit less than this, but this current is what you would have to run around to get near the 45W you are looking for.

Citizen



Citizen.1212C4.3000K 50 COBS @1.4A ON 5.88 PROFILE HEATSINK
50 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 2688.3
Cobs power watts: 2527
Total voltage forward: 1805
Total lumens: 368942
Total PAR watts assuming 10% loss: 1012
Total PPF: 4918.32
PPFD based on canopy area: 1058.81
PAR watts per sq.ft.: 20.24
Cob efficiency: 44.51%
Power watts per sq.ft.: 50.54
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: 1402
umol/s/W / CRI: 4.86 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 647 inches
Heatsink length active cooling @40cm^2/heatwatt: 216 inches
COB cost dollar per PAR watt: $0.62
Electric cost @12/12 in 30 days: $145.67
Electric cost @18/6 in 30 days: $218.25
Cost per cob: $12.55
Heatsink cost per inch cut: $1.74
Total cobs cost: $628
Total heatsink passive cooling cost: $1126
Total heatsink active cooling cost: $375




VERO



VERO29.V2.0.4000K 40 COBS @1.4A ON 5.88 PROFILE HEATSINK
50 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 2197.87
Cobs power watts: 2066
Total voltage forward: 1476
Total lumens: 293703
Total PAR watts assuming 10% loss: 816
Total PPF: 3769.92
PPFD based on canopy area: 811.58
PAR watts per sq.ft.: 16.32
Cob efficiency: 43.88%
Power watts per sq.ft.: 41.32
Voltage forward per cob: 36.9
Lumens per watt: 142.16
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: 1159
umol/s/W / CRI: 4.62 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 535 inches
Heatsink length active cooling @40cm^2/heatwatt: 178 inches
COB cost dollar per PAR watt: $1.2
Electric cost @12/12 in 30 days: $119.18
Electric cost @18/6 in 30 days: $178.53
Cost per cob: $24.38
Heatsink cost per inch cut: $1.74
Total cobs cost: $975
Total heatsink passive cooling cost: $931
Total heatsink active cooling cost: $309
 

MeGaKiLlErMaN

Well-Known Member
so is there any combo where the citi cobs break the 45% eff barrier ? does it happen@ 700ma maybe?
yes of course, its also not a bad spot to be. still cheaper than a few COBs.


Citizen.1212C4.3000K 50 COBS @0.5A ON 5.88 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 882.98
Cobs power watts: 830
Total voltage forward: 1660
Total lumens: 141930
Total PAR watts assuming 10% loss: 388
Total PPF: 1885.68
PPFD based on canopy area: 1268.58
PAR watts per sq.ft.: 24.25
Cob efficiency: 52.0%
Power watts per sq.ft.: 51.88
Voltage forward per cob: 33.2
Lumens per watt: 171.0
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: 398
umol/s/W / CRI: 4.86 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 184 inches
Heatsink length active cooling @40cm^2/heatwatt: 61 inches
COB cost dollar per PAR watt: $1.62
Electric cost @12/12 in 30 days: $48.18
Electric cost @18/6 in 30 days: $72.02
Cost per cob: $12.55
Heatsink cost per inch cut: $1.74
Total cobs cost: $628
Total heatsink passive cooling cost: $320
Total heatsink active cooling cost: $106
 

sixstring2112

Well-Known Member
yes of course, its also not a bad spot to be. still cheaper than a few COBs.


Citizen.1212C4.3000K 50 COBS @0.5A ON 5.88 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 882.98
Cobs power watts: 830
Total voltage forward: 1660
Total lumens: 141930
Total PAR watts assuming 10% loss: 388
Total PPF: 1885.68
PPFD based on canopy area: 1268.58
PAR watts per sq.ft.: 24.25
Cob efficiency: 52.0%
Power watts per sq.ft.: 51.88
Voltage forward per cob: 33.2
Lumens per watt: 171.0
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: 398
umol/s/W / CRI: 4.86 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 184 inches
Heatsink length active cooling @40cm^2/heatwatt: 61 inches
COB cost dollar per PAR watt: $1.62
Electric cost @12/12 in 30 days: $48.18
Electric cost @18/6 in 30 days: $72.02
Cost per cob: $12.55
Heatsink cost per inch cut: $1.74
Total cobs cost: $628
Total heatsink passive cooling cost: $320
Total heatsink active cooling cost: $106
sweet can you run the cree 36v at that same current for me so i can compare them?
 

MeGaKiLlErMaN

Well-Known Member
sweet can you run the cree 36v at that same current for me so i can compare them?
no but I can get close 700mA instead of 500mA


CXB3590CD36V3500K 25 COBS @0.7A ON 5.88 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 609.57
Cobs power watts: 573
Total voltage forward: 818
Total lumens: 118834
Total PAR watts assuming 10% loss: 330
Total PPF: 1534.5
PPFD based on canopy area: 1032.33
PAR watts per sq.ft.: 20.63
Cob efficiency: 64.01%
Power watts per sq.ft.: 35.81
Voltage forward per cob: 32.72
Lumens per watt: 207.39
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: 206
umol/s/W / CRI: 4.65 / Estimated
Heatsink length passive cooling @120cm^2/heatwatt: 95 inches
Heatsink length active cooling @40cm^2/heatwatt: 32 inches
COB cost dollar per PAR watt: $3.61
Electric cost @12/12 in 30 days: $33.42
Electric cost @18/6 in 30 days: $49.88
Cost per cob: $47.62
Heatsink cost per inch cut: $1.74
Total cobs cost: $1191
Total heatsink passive cooling cost: $165
Total heatsink active cooling cost: $55



Heres a better comparison



Citizen.1825C4.3000K 25 COBS @0.5A ON 5.88 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 642.55
Cobs power watts: 604
Total voltage forward: 1208
Total lumens: 108116
Total PAR watts assuming 10% loss: 297
Total PPF: 1443.42
PPFD based on canopy area: 971.05
PAR watts per sq.ft.: 18.56
Cob efficiency: 54.57%
Power watts per sq.ft.: 37.75
Voltage forward per cob: 48.3
Lumens per watt: 179.0
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: 274
umol/s/W / CRI: 4.86 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 126 inches
Heatsink length active cooling @40cm^2/heatwatt: 42 inches
COB cost dollar per PAR watt: $3.6
Electric cost @12/12 in 30 days: $35.2
Electric cost @18/6 in 30 days: $52.55
Cost per cob: $42.8
Heatsink cost per inch cut: $1.74
Total cobs cost: $1070
Total heatsink passive cooling cost: $219
Total heatsink active cooling cost: $73
 

mauricem00

Well-Known Member
I am planning to get either

40 x Vero 29 3500k 80 CRI and run each at 50W per 1.25 sq ft - giving 192 Lumens per watt.
or
50 x Citizen 1212 3500k 80 CRI and run each at 45w per 1 sq ft - giving 160 Lumens per watt

total space for these is 5x10 ft, so 50 sq ft.

Would either of these builds provide a good enough PPFD?

I am not actually familiar with this measurment, in the past I have used HPS and never heard of it...

Could somebody post measurments for both of these builds

Many thanks!
how are you getting 192 lpw out of a vero 29 ?http://www.bridgelux.com/sites/default/files/resource_media/DS33 Vero 29 Array Data Sheet Rev L 20160606.pdf
 

sixstring2112

Well-Known Member
no but I can get close 700mA instead of 500mA


CXB3590CD36V3500K 25 COBS @0.7A ON 5.88 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 609.57
Cobs power watts: 573
Total voltage forward: 818
Total lumens: 118834
Total PAR watts assuming 10% loss: 330
Total PPF: 1534.5
PPFD based on canopy area: 1032.33
PAR watts per sq.ft.: 20.63
Cob efficiency: 64.01%
Power watts per sq.ft.: 35.81
Voltage forward per cob: 32.72
Lumens per watt: 207.39
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: 206
umol/s/W / CRI: 4.65 / Estimated
Heatsink length passive cooling @120cm^2/heatwatt: 95 inches
Heatsink length active cooling @40cm^2/heatwatt: 32 inches
COB cost dollar per PAR watt: $3.61
Electric cost @12/12 in 30 days: $33.42
Electric cost @18/6 in 30 days: $49.88
Cost per cob: $47.62
Heatsink cost per inch cut: $1.74
Total cobs cost: $1191
Total heatsink passive cooling cost: $165
Total heatsink active cooling cost: $55



Heres a better comparison



Citizen.1825C4.3000K 25 COBS @0.5A ON 5.88 PROFILE HEATSINK
16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 642.55
Cobs power watts: 604
Total voltage forward: 1208
Total lumens: 108116
Total PAR watts assuming 10% loss: 297
Total PPF: 1443.42
PPFD based on canopy area: 971.05
PAR watts per sq.ft.: 18.56
Cob efficiency: 54.57%
Power watts per sq.ft.: 37.75
Voltage forward per cob: 48.3
Lumens per watt: 179.0
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: 274
umol/s/W / CRI: 4.86 / 80CRI
Heatsink length passive cooling @120cm^2/heatwatt: 126 inches
Heatsink length active cooling @40cm^2/heatwatt: 42 inches
COB cost dollar per PAR watt: $3.6
Electric cost @12/12 in 30 days: $35.2
Electric cost @18/6 in 30 days: $52.55
Cost per cob: $42.8
Heatsink cost per inch cut: $1.74
Total cobs cost: $1070
Total heatsink passive cooling cost: $219
Total heatsink active cooling cost: $73
ya see where im goin with this right hahaha.
 

Joe34

Active Member
@visajoe1

Thanks for the calculations, are those figures you gave for my builds considered ok? Or should I be changing anything?

@MeGaKiLlErMaN


Again same as Question above.

I thought my efficiency for vero would be better than 45 -/+3 considering I am getting 190 L/pw


@mauricem00

The vero 29 spec sheet u linked to is old, here is the latest http://www.bridgelux.com/sites/default/files/resource_media/Bridgelux DS93 Vero 29 Gen 7 Array Data Sheet 20170208 Rev I.pdf

If you open that spec sheet and type CTRL + F to find, search for "BXRC-35E10K0-C-7X".
Skip the first entry and goto the next match, you will see that if you run that COB at around 55W you get 190 L/pw,
You can get even better by running it at around 45W, which gives 196 L/pw
 
Last edited:

MeGaKiLlErMaN

Well-Known Member
@visajoe1

Thanks for the calculations, are those figures you gave for my builds considered ok? Or should I be changing anything?

@MeGaKiLlErMaN


Again same as Question above.

I thought my efficiency for vero would be better than 45 -/+3 considering I am getting 190 L/pw


@mauricem00

The vero 29 spec sheet u linked to is old, here is the latest http://www.bridgelux.com/sites/default/files/resource_media/Bridgelux DS93 Vero 29 Gen 7 Array Data Sheet 20170208 Rev I.pdf

If you open that spec sheet and type CTRL + F to find, search for "BXRC-35E10K0-C-7X".
Skip the first entry and goto the next match, you will see that if you run that COB at around 55W you get 190 L/pw,
You can get even better by running it at around 45W, which gives 196 L/pw
It will be a bit better than that. That's gen 2
 

sixstring2112

Well-Known Member
cree 3590 can be had for around 31.00 these days,so how long would it take to cover the extra cost when your gaining 10% eff right away? the citi cobs look to be around the same eff as a cmh/lec setup is right now.40% and better spectrum from the lec is almost a no brainer.
 

Joe34

Active Member
cree 3590 can be had for around 31.00 these days,so how long would it take to cover the extra cost when your gaining 10% eff right away? the citi cobs look to be around the same eff as a cmh/lec setup is right now.40% and better spectrum from the lec is almost a no brainer.
Thats not true, Citi's and Veros can be ran at greater efficiency than CREE... Depends mostly on how they are used.
 

sixstring2112

Well-Known Member
Thats not true, Citi's and Veros can be ran at greater efficiency than CREE... Depends mostly on how they are used.
just like you asked,most of us run these cobs at 50w or less,and at those currents citi as well as the 36v vero dont stack up better than cree,in fact based on the calcs in this thread citi rated poorly under 50w.the citi wheelhouse is over 75w if i recall from a few members calcs here.10 to 15% eff lose is huge imo,as to why i said you might as well run a cmh if 40% is the goal heat loads will be identical.
 

MeGaKiLlErMaN

Well-Known Member
just like you asked,most of us run these cobs at 50w or less,and at those currents citi as well as the 36v vero dont stack up better than cree,in fact based on the calcs in this thread citi rated poorly under 50w.the citi wheelhouse is over 75w if i recall from a few members calcs here.10 to 15% eff lose is huge imo,as to why i said you might as well run a cmh if 40% is the goal heat loads will be identical.
I would have to look at @CobKits charts and say that run a higher PPF/W that Cree at the same current
 
Top