Lighting Horribly out of my depth ...

[Yozhik]

OK - so I'm sure this has been asked a BILLION times before ...
So what's one more time, right?

I have no freakin' clue.
Let's just start of from that premise. It will save us all a whole lot of time and ridicule.

I need some advice and opinion.

3 x Citizen 1818 + 1 x Meanwell HLG-240C-1400B

OR

4 x Citizen 1818 + 1 x Meanwell HLG-240C-1400B


1. Which config?
2. Why?
3. Estimated footprints?

Thanks!!

 

[Yozhik]

Wait ... I think the driver is wrong.

Looks like it would need the 2100mA

Yes?
No?




EDIT:

Nope ... C1750B looks a real good choice.
IF my novice understanding is sound.

From cobkits.com:
CLU-1818 is a nominal 50V COB which can operate up to 4.14A max (approximately 250W). Best efficiency is seen below 150W with this chip. The 1818 is typically more efficient above 90W

Sooooooo ... 90W to 150W would be optimal.

If it's ... 250W @ 4.14A
Then ... 105W @ 1.75A
Or ... 126W @ 2.1A

Yes?

 

[KonopCh]

Every chip is more efficient at lower current than at higher current.
You must decide how hard you'll drive those COBs and how much you want (tent size, coverage). I would go with 30-50W per COB per square foot. It's the most simple number how much COBs you need.

3500K 80 CRI, 1818 gen 6 at Tc 60°C, driven at 1.75A gives you 90,7W, 51,8V, 148 lm/W, Tj 75°C.
On HLG-240H-C1400B you can drive 3 of them.

 

[Dr.Bubbles]

I got Six 1818s running off two Meanie HLG-240-c1050b, three off each driver. To get the wattage just multiply volts x amps. For example, 50v x 1.050 amps = 52.5w each. They are real happy at that power level, and they don't get too hot. The more power you throw at them the less efficient they become. More cobs at lower power is always better than one or two going nuclear. Also, they can be difficult to cool when you start lighting em up with a ton of juice. Check out this link to the Constant Current Driver selection tool from LED Gardener. It's real handy for selecting parts that play well together. Good luck.

http://ledgardener.com/cob-led-driver-selection-tool/

Sent from my XT1254 using Tapatalk

 

[BigSm0]

If your running autos I’d go 15-30 watts per square foot. For photos 30-50. The guys in Riu grow photos and their recommendations don’t fit autos. 12 hours per day with photos and 18-24 hours per day with autos. Any more wattage is a waste of money.

 

[Yozhik]

If your running autos I’d go 15-30 watts per square foot. For photos 30-50. The guys in Riu grow photos and their recommendations don’t fit autos. 12 hours per day with photos and 18-24 hours per day with autos. Any more wattage is a waste of money.

This is actually really important, and something easily forgotten


Sooooooooooo - if I'm planning to do both - then the common denominator is 30W/ft² ... I.e. The upper limit of Autos, and the lower limit of photos.

1 tent = 3m x 2m = 6m² [ 64ft² ]

64ft² x 30W = 1,920W

or 38 COBs @ 50W

 

[iampepe]

I'm using the hlg-320h-1400b on 4 1818's @75watts a piece
works good in 4 x 4

 

[Yozhik]

[ rant ]

I think where I'm getting "fucked up" is conflicting thoughts in my head.

For example, I absolutely remember a time, when HPS was King, and LEDs were the ugly, spotty faced new kid on the street, who was bullied every day.
That's when you were a living God if you hit the Holy Grail of 1g/W and 50W/ft² was where everyone aspired to having their grow spaces.

Then we went through that horrible time of outrageous claims, by some less than honest LED manufacturers, promoting their new snake oil about X Watts of LED = 4X Watts of HPS, blah blah blah ...

Thankfully we survived that.

And so here we are, in the Brave New World of efficiency offered by COBs and QBs.


I am left scratching my head at how many W/ft² are actually needed, and balancing that with the new efficiencies.

Have we just become greedy for light, and drunk on Lumens?
At what point does the amount of COB and QB light become surplus to requirements, and our ego is merely fuelling an inefficiency that isn't plant related?

Ugh ... Sorry for the [ /rant ]

 

[MassMom]

If your running autos I’d go 15-30 watts per square foot. For photos 30-50. The guys in Riu grow photos and their recommendations don’t fit autos. 12 hours per day with photos and 18-24 hours per day with autos. Any more wattage is a waste of money.

Hi BigSM0!! A mutual friend here on AFN suggest I check out your posts

I am currently using a couple of LED's off ebay. yuck. I am very interested in COB. question for you~ is this blonde's math correct?

3’ x 2’ tent = 6sq feet
cobs 30w per square foot
30w x 6sq ft = 180w
= (4) 50w cobs

I was checking out this thread and am dying to get a couple, but this moms budget is so tight (4) of these is a dream for now.

https://www.autoflower.org/threads/autocob-55-watt-cob-led-grow-light.56994/

Maybe I should ask Santa? LOL

 

[BigSm0]

Hi BigSM0!! A mutual friend here on AFN suggest I check out your posts

I am currently using a couple of LED's off ebay. yuck. I am very interested in COB. question for you~ is this blonde's math correct?

3’ x 2’ tent = 6sq feet
cobs 30w per square foot
30w x 6sq ft = 180w
= (4) 50w cobs

I was checking out this thread and am dying to get a couple, but this moms budget is so tight (4) of these is a dream for now.

https://www.autoflower.org/threads/autocob-55-watt-cob-led-grow-light.56994/

Maybe I should ask Santa? LOL

Hey there,
Id personally go with 2 cobs. If you went with 3 that would definitely be on the upper limit and 4 would probably do damage if you didn't have 8' ceilings.

Shipping is quick as I'm the little state right next to you. 7% sale going too.