Help with first Cob build

Dreddd

Dreddd

Well-Known Member
Hello everyone, i need some help because i've been reading nonstop for the past week and the more i read the more confused i get,
i'm aiming for a 4 cob light at around 200-250w total, i want 3500k 90 CRI cobs and obviously the best lm/W i can get.

Do i go with 4 Citizen 1812 3500k 90 CRI @ 1080mA? or do i get better efficiency by going with 4 1818's @ 1080mA? maybe even 4 1825's @ 1080mA???

What about the CREE CXB3590 3000k 90 CRI? (the 3000k 90cri spectrum looks exactly like the Citizen 3500k 90 cri and i cant find a spectrum graph for the Cree 3500k 90 cri) should i get 4 of those and run them at 50w each? would that be more efficient then the Citizens?

How about the Vero29 gen 7? cant find a spectrum graph of the 3500k 90 cri so i dont know what it looks like or what efficiency 4 of these will give me at around 50w per cob.


Help... :wall:
 
V

VegasWinner

Well-Known Member
If you are going to use a tent, I would go with the 4-cxb3590, 3500k, 36v with 1-HLG-185H-C1400A meanwell driver. The cxb's can be driver softer than the Vero's allowing for more efficient light. TYhat is my view, others may differ. I use cxb's with no complaints, whatsoever. low power, low heat, high production.
 
HydoDan

HydoDan

Well-Known Member
HLG 240 H C1750B with 4 Cree 3590 cobs would be my choice. This gives you a dimmable 250 watt light... You could use citizen cobs to save $.. I'm running a Timber kit with a
hlg 320 1400b 6 3590s in a 2x4 tent...love it!!
 
nl5xsk1

nl5xsk1

Well-Known Member
Im running 2 sets , 8 cobs total, on two the 185-1400's in a 36"x43" foot print, dimmed to 300W . day 28, cherry pie20170310_211437.jpg
 
Dreddd

Dreddd

Well-Known Member
VegasWinner said:
If you are going to use a tent, I would go with the 4-cxb3590, 3500k, 36v with 1-HLG-185H-C1400A meanwell driver. The cxb's can be driver softer than the Vero's allowing for more efficient light. TYhat is my view, others may differ. I use cxb's with no complaints, whatsoever. low power, low heat, high production.
Click to expand...
Yeah i figured i could go for something like that, the real question is what lm/W i'll be getting from that setup, i mean i know from their datasheet what lm/W to expect at nominal current, but how do i calculate the efficiency when i under/over drive them? and how would this setup compare to the same driver but with citizens cobs instead, i mean initial cost is also a factor for me and citizens are cheaper...

HydoDan said:
HLG 240 H C1750B with 4 Cree 3590 cobs would be my choice. This gives you a dimmable 250 watt light... You could use citizen cobs to save $.. I'm running a Timber kit with a
hlg 320 1400b 6 3590s in a 2x4 tent...love it!!
Click to expand...
if you had to compare this 4 3590 cobs setup to an HPS, how many watts would you say this is equivalent of? 600W? or is that overly optimistic?

nl5xsk1 said:
Im running 2 sets , 8 cobs total, on two the 185-1400's in a 36"x43" foot print, dimmed to 300W . day 28, cherry pieView attachment 3904331
Click to expand...
what cobs? and 300W for all 8 cobs?



Thanks everyone.
 
nl5xsk1

nl5xsk1

Well-Known Member
Dreddd said:
Yeah i figured i could go for something like that, the real question is what lm/W i'll be getting from that setup, i mean i know from their datasheet what lm/W to expect at nominal current, but how do i calculate the efficiency when i under/over drive them? and how would this setup compare to the same driver but with citizens cobs instead, i mean initial cost is also a factor for me and citizens are cheaper...


if you had to compare this 4 3590 cobs setup to an HPS, how many watts would you say this is equivalent of? 600W? or is that overly optimistic?



what cobs? and 300W for all 8 cobs?



Thanks everyone.
Click to expand...
Im running the 3590's from Cutters. These are turned down, max setting is 400Watts. Equivalent to my 600w hps and runs around 2.7Amps.
 
Dreddd

Dreddd

Well-Known Member
I see there's another 300W light just with Citizens CLU048-1212's instead of Cree's for $150 less and if i'm calculating the lumen output at 1400mA it looks like the Citizens are slightly more efficient? did i get this right?

Lumen output for the Citizens 3500k 80 CRI @ 1080mW / 85C is 5702lm, at 1400mW they get a 30% increase in output so that makes the output 7412lm per Citizen cob.

Lumen output for the Crees 3500k 80 CRI @ 2400mA / 85C (top bin) is 12000lm, at 1400mW they get a 40% decrease in output making the output 7200lm per Cree cob.

So did i get these figures right? is the Citizen setup not only $150 cheaper but also more efficient?
 
majins

majins

Well-Known Member
Cree you pay extra for the name since they use to be the only worth while COBs you could get.
 
HydoDan

HydoDan

Well-Known Member
When I bought mine, nothing else was close.. now 8 months later .. I'm looking at the citi''s for another grow tent..
Save your money..
 
HotBunz

HotBunz

Active Member
Dreddd said:
I see there's another 300W light just with Citizens CLU048-1212's instead of Cree's for $150 less and if i'm calculating the lumen output at 1400mA it looks like the Citizens are slightly more efficient? did i get this right?

Lumen output for the Citizens 3500k 80 CRI @ 1080mW / 85C is 5702lm, at 1400mW they get a 30% increase in output so that makes the output 7412lm per Citizen cob.

Lumen output for the Crees 3500k 80 CRI @ 2400mA / 85C (top bin) is 12000lm, at 1400mW they get a 40% decrease in output making the output 7200lm per Cree cob.

So did i get these figures right? is the Citizen setup not only $150 cheaper but also more efficient?
Click to expand...
Provided this data is correct my next fixture build will be a Citizen 1212 unit. I was thinking a 1818 COB unit but it looks like the 1212's on a Meanwell hlg-185h-1400c driver would be equal to my current 4 COB cxb3590 fixture with the same driver and for a lot less of an investment.
 
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