what's my next step?

Iceveign

Active Member

• Aug 16, 2015

• #1

I have ordered 6 cxb 3590cd 3500k 36v cobs from kingbrite.

My room is 2ft.W x 6ft.L x 8ft.H

I would like to run the drivers at either 700mA or 1.4A, unless there is a better suggestion.

I was thinking of either 2 heat sinks with 3 lights each or 3 heat sinks with 2 light each.

I know I could do 4 lights on 1 heat sink with Supraspl's efficiency chart

Supraspl:

@ 56.3%
(4) CXB3590 3500K CD 36V @ 1.4A (49W ea) $190
(1) HLG-185H-C1400 $65
196 dissipation W -> 85.7W heat ->
passive cooled heatsink 10284cm² -> 5.88" X 38" heatsink $72 (could split in 2 to improve uniformity/spread)
or
active cooled heatsink 3428cm² min -> 3.5"X36" heatsink (for spread) $45 +80mm fan +psu $10
(4) lenses $16
110.3 PAR W covering 6ft² = 824 PPFD
$311 = $3.07/PAR W passive cooled (great value point IMO, very efficient use of driver)
$326 = 2.96/PAR W active cooled

But then I would have to cobs left and Supraspl's chart for 2 isn't as efficient.

Supraspl:
@45.7%
(2) CXB3590 3500K CD 36V @ 2.5A (91.65W ea) $95
(2) HLN-80H-36A $90
183 dissipation W -> 99.37W heat
(2) Arctic 64 Plus CPU coolers $26
(2) lenses $8
83.63 PAR W covering 5 ft² = 749 PPFD
$219 = 2.62/PAR W

Does anyone have any suggestions on heat sink size and driver and the best way to split up 6 cobs...wish I would have bought 8 but didn't have the money.

Thank you for any advice.

 

CanadianONE

Well-Known Member

• Aug 16, 2015

• #2

Most aim for 30W/sq ft. You will only be getting about 25W/sq ft with 6 COB's around 50watts a piece. As far as what to do for setup check out some of the other threads there is a ton of info floating around. Just need to do a little investigation and you will find all your answers.

 

Iceveign

Active Member

• Aug 16, 2015

• #3

I have been reading quite a few threads, but I admit I have not read all 330 pages of https://www.rollitup.org/t/if-you-a...t-help-choosing-what-to-buy-post-here.633304/
And I doubt I will.

I will only be growing 1 or 2 plants, so I don't have to have the whole 12 square ft covered.

I'm just looking for a little help.

 

bicit

Well-Known Member

• Aug 16, 2015

• #4

Hlg-185h-c1050a to run 6 cobs. Hlg-120h-c1400 will run 3.

300w over a 2x6 driven at 1.4 amp is ~700umol with less than optimal distribution.

All power used in a space ends up as heat in the space.

 

Iceveign

Active Member

• Aug 16, 2015

• #5

Thanks Bicit, so your saying those are 2 ways of running 3 and 6 cobs but they are not ideal?

 

bicit

Well-Known Member

• Aug 16, 2015

• #6

Basically. Thw 150w supply is enough to run three and you'll need two drivers for all your emitters. Or you can run all six on the 200w supply.

 

captainmorgan

Well-Known Member

• Aug 16, 2015

• #7

I'll be ordering parts for a new light shortly. Planning a passive cooled CXB 3590 CD 3500k build at 700 ma or 800 ma,I'll be using 9 of them for a 3x3 area.

 

Iceveign

Active Member

• Aug 16, 2015

• #8

So Captain, how many watt's will you be getting out of each cob and what driver/drivers do you plan to use?

 

captainmorgan

Well-Known Member

• Aug 16, 2015

• #9

I'll probably get some lightly used 800 ma drivers from another member here.

Using 9 of the 800mA drivers:
9 CXB3590 CD 3500k at .8A (26.5W) 62.3% efficient in a 3X3 = 14.9 PAR W/ft² or 740 PPFD averaged, 90W heat

 

Iceveign

Active Member

• Aug 16, 2015

• #10

I like that setup. I'll probably only utilize 8 sq. ft. of the available 12 sq. ft. for growing. Trying to be stealthy for a couple of plants at a time. Never no when Mom or nieces and nephews my drop by. Finding out I'm doing this is not at option.

 

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Last edited: Aug 16, 2015

captainmorgan

Well-Known Member

• Aug 16, 2015

• #11

There are some good silent inline fans on the market,pricey but worth it for stealth along with a good carbon filter.

 

gk skunky

Well-Known Member

• Aug 16, 2015

• #12

I'd do 8 or 9 of those @1.4A for a 2x6 area. 3 panels,each with one of the Hlg-120h-c1400 run 3 CXB 3590s. That's what i would do.

 

Iceveign

Active Member

• Aug 16, 2015

• #13

I have a Phresh carbon filter and hyperfan in my tent, so I'm good there. But I only have a mars hydro reflector series 96w x 3 and the 2 plants just are not budding like I know they should be. Thus my leap into diy led cobs and the process of learning mathematics all over again,lol.

 

Iceveign

Active Member

• Aug 16, 2015

• #14

Unfortunately GK I already have 6 on the way with no more money available for cobs. I bought as many as I could afford from Kingbrite. I think I'll focus on utilizing enough space for 1 plant and add to it as funds become available.

 

Iceveign

Active Member

• Aug 16, 2015

• #15

Think I'll go with Supraspl's post of efficiency chart for now.

@ 56.3%
(4) CXB3590 3500K CD 36V @ 1.4A (49W ea) $190
(1) HLG-185H-C1400 $65
196 dissipation W -> 85.7W heat ->
passive cooled heatsink 10284cm² -> 5.88" X 38" heatsink $72 (could split in 2 to improve uniformity/spread)
or
active cooled heatsink 3428cm² min -> 3.5"X36" heatsink (for spread) $45 +80mm fan +psu $10
(4) lenses $16
110.3 PAR W covering 6ft² = 824 PPFD
$311 = $3.07/PAR W passive cooled (great value point IMO, very efficient use of driver)
$326 = 2.96/PAR W active cooled

That will be good right?

 

captainmorgan

Well-Known Member

• Aug 16, 2015

• #16

I've pulled huge numbers from 529 PPFD using CXA3070's.

 

gk skunky

Well-Known Member

• Aug 16, 2015

• #17

If you already ordered and no more funds no biggie. You'll still get a good haul. And you could definitely do more than one plant under that light. I have about 10 under my 6-cxa 3070 z4 fixture covering 2x4 of my 4x4. Not saying just go throw 10 under yours, but if you want more than one definitely no issue there.

@captainmorgan could you point me in the direction for the ppfd calculations? Curious what mine roughly is.

 

captainmorgan

Well-Known Member

• Aug 16, 2015

• #18

gk skunky said:

@captainmorgan could you point me in the direction for the ppfd calculations? Curious what mine roughly is.

Click to expand...

I actually never did the PPFD numbers on my set up but while I was talking with supra about my new build he ran the numbers on both for comparison,the guy is a wiz with the number crunching. Here's what he came up with on my CXA's.

5 of the CXA3070 3000K @ 1.4A (52W) 40.7% efficient in a 3X3 = 10.6 PAR W/ft² or 529 PPFD averaged, 154W heat

 

Abiqua

Well-Known Member

• Aug 17, 2015

• #19

gk skunky said:

If you already ordered and no more funds no biggie. You'll still get a good haul. And you could definitely do more than one plant under that light. I have about 10 under my 6-cxa 3070 z4 fixture covering 2x4 of my 4x4. Not saying just go throw 10 under yours, but if you want more than one definitely no issue there.

@captainmorgan could you point me in the direction for the ppfd calculations? Curious what mine roughly is.

Click to expand...

Just realized that you didn't quite specify what you drive them at but....

6x 3070's @ 1.4amps =313.32 watts @ [39.32% efficiency] = 123. 2 PAR Watts Emitted

The Cree CXA3070's = 4.66 joules/PAR watt.... [4.6*123.2]= 574 umol/s emitted

[1 square meter = 1550 inches^2 [1549.99] [2'x4' = 1152 in^2] = .74 meter Actual Space

574 / .74 = 775.675 PPFD averaged....

 

gk skunky

Well-Known Member

• Aug 17, 2015

• #20

Abiqua said:

Just realized that you didn't quite specify what you drive them at but....

6x 3070's @ 1.4amps =313.32 watts @ [39.32% efficiency] = 123. 2 PAR Watts Emitted

The Cree CXA3070's = 4.66 joules/PAR watt.... [4.6*123.2]= 574 umol/s emitted

[1 square meter = 1550 inches^2 [1549.99] [2'x4' = 1152 in^2] = .74 meter Actual Space

574 / .74 = 775.675 PPFD averaged....

Click to expand...

Awesome! Thanks! That is probably pretty close. Thats the current I run. Though not sure if you used AB bins. Mine are z4 because thats all supra or anyone else had at the time. Either way gives me a good idea.