COB Leds for a2x2 closet?

Discussion in 'LED and other Lighting' started by Fawkes420, Feb 7, 2018.


    Fawkes420 Member

    First post here and i just getting my self inte the world of cob leds.
    I got a tip from a friend about cobs, and he suggested to me buying the following:
    1. 2 pcs vero 29 30G10K0-B-73 SE
    2. Meanwell hlg-240h-c1750b

    I want cobs that will work good on both veg and bloom.

    I will build the frame by myself and i have a plan to build it.

    What du you guys think?
    Would it be sufficent with only 2 cobs?
    Is the driver the one that i need?
    Planning to grow 4 plants at a time.

    Best regards from Sweden

    Nutria Well-Known Member

    Since you are EU based:
    Export-estonia on ebay sells 5x Citizen 1212 for 50euro. I would always go for more light sources than fewer. You can use 4 cobs and keep a spare one.

    Btw you also need heatsinks, holders, wires.
    Didn't you think about a led strip build? From the same seller you can get TCI strips used in this thread.
    coreywebster and Moflow like this.

    Fawkes420 Member

    Thanks for answer.
    Yes, i now about heatsink etc.
    So you think that 2 pcs are to few? It sounds so to me, that why i asked ;).

    Is holder necessery? I 'm planning to use active cooling with a cpu cooler heatsing with fan, and drill holes in the heatsing and screw the cobs there.

    Nutria Well-Known Member

    Veros do not need holders. Citizens do.
    You can even use a single cob to light up your 2x2 but I prefer to have a more light sources, that is why I am using 4x Citizen gen6 1212 3000k 90cri in my 2x2ft and I am happy with this setup.
    Fewer cobs have to be driven at higher current, more cobs at lower current to match the same total wattage.
    Active cooling for cpu is cheap on amazon, I would go for artic alpine 11 heatsink with fan or similar.

    If I am to build a light setup now I would go for led strips.

    wietefras Well-Known Member

    I'd go for five 56cm led strips. 125W would be plenty of led power for that space.

    So five of these SI-B8V261560WW Samsung F-Series Gen3, 56cm single row 3000K strips:,ffe0006f,b88b96

    For the driver a HLG-120H-C1050 would work.

    This is a 150W driver so potentially you could add a sixth led strip. Then either dim it down to 125W for a little extra efficiency or leave it at max power for a bit extra light.

    An aluminium U channel works fine as a heat sink.
    nfhiggs, 1212ham and Nutria like this.

    Fawkes420 Member

    Ok. Maybe i go for led strips instead. However, correct me if i 'm thinking wrong, but if i mount all strips on a plate that nearly covers the area of the closet.
    Wouldn't that be negative for airflow since my fan outtake is above (mounted on wall) and the inlets (passive) are at the bottom? I can't move the fan to be under the plate, if i do, i wan't be able to sink the plate to desired hight.

    1212ham Well-Known Member

    Don't use a plate, make a frame from aluminum angle.Those strips don't need heat sink at nominal current, so the frame could just be a square perimeter. Or attach strips to aluminum angles on the frame.

    Fawkes420 Member

    Yes. I came to the same solution :).

    Fawkes420 Member

    Hi again.
    I have measured my closet and it is not exactly 2x2, ( it is 58x57 cm) so the Sammys will be liittle tight with frame and so.

    So i have been looking at Ledgardener and his suggestion for a 2x2 space with 1' strips
    (Bridgelux Gen. 2 BXEB-L0560Z1′ LED Strip Build – 2’x2′). It has a very attractive price.
    What do you guys think abot that setup?

    And, is there a reason he uses parallel circuit? Seems much cleaner with series circuits thinking about wireing and so.

    If it's up to me to choose wireing method,,,, what driver would you suggest for series circuit with 12 strips?

    As you can see, i don't know so much about led, but i'm learning (hopefully).
    Last edited: Feb 7, 2018

    GBAUTO Well-Known Member

    I'd prefer to run parallel circuits when running strips. The uniformity is better than most cobs so having a strip that runs brighter than the others shouldn't be an issue. It's also safer-much lower DC voltage to work with so no electrocution.

    Fawkes420 Member

    I decided to go for a setup 2x2 space with 12 strips and a HLG-120H-20B as suggested by Ledgardener.
    However, it seems like the driver is sold out where i lookedbut, i found HLG-150H-20A .
    I now what the "A" stands for insted of "B", and i think it would be better for me.
    My Q now is..... I guess i can run this 150W insted of 120W? I think the main thing to check is that the current (20) is right. Right?

    nfhiggs Well-Known Member

    That is actually the voltage, not the current. Its a 20 volt constant voltage driver. The 1 foot strips are run at a test current of 350 mA @19.5V for 6.825 watts per strip, so yes that driver would work. However 6.825 x 12 is only 80 watts. They have a maximum current rating of 700 mA, but running them at a higher current *may* require heat sinks. I would use a few more strips, or a try to find a 120W driver.

    Fawkes420 Member

    Ahh, sorry. I see now that the number "20" is voltage. But then you lost me.

    Why's that his setup is recomended at the ledgardener site. I can't post links so i copy/paste from his site.

    System Specs:
    Type: C.V./Parallel

    Diode Count: 672

    System Voltage: 19.6V

    System Current: 6,000mA

    System Power: 117.6W

    Lumen Estimate (3000K): 20,160

    Efficacy: 171 lm/w

    Can you explain for me why youget about 80w, and he gets 117.6?
    Or is this not the same value?
    Getting more and more confused right now :?
    nfhiggs likes this.

    nfhiggs Well-Known Member

    80 W is running them at their test current. Everyone has their own preferences. I prefer to stay at or below test current. His build runs them a little bit higher at 500 mA. Not saying it won't work or anything like that, its just my own preferences would be to toss in a few more and run them softer.

    Fawkes420 Member

    Ahh, i think he runs at 75%.
    "We’ll shoot for around 30 watts per square foot and aim to drive the strips at about 75% of their rated max."
    I guess if i drive strip att 75%, i need heatsink, but that is not a problem since i planning to use a alu U-channel for mounting.

    nfhiggs Well-Known Member

    If you plant on mounting them to channel then you should be fine up to max current.

    Fawkes420 Member

    Great. Thanks!
    Rocket Soul

    Rocket Soul Well-Known Member

    Hej, Fawkes420, hur e läget?

    Whats the heigjt of your closet? Your first proposal: vero Bs at 1750 needs probably 50 cm height above cannopy. Also needs big heatsink or active cooling.
    But spectrum 3000k/90 cri is good, gives a bit more stretch in vegg but a bit less in flower although strain dependent. This spectrum is not available for strips. But 80 cri grows very well as well so shouldnt be a problem.

    Maybe consider these:

    Like quatumboards but sold in eu. Ive been in touch with the company and they seem legit, but its a new board so its still taking a chance, noone here has been ble to confirm the diodes 100% but i still feel pretty sure about them.

    They recommend one board for 2x2: my recomendation is to get 2 boards and run them around 120w total. Why? No heatsink needed at low wattage and even if the diodes where not top bin, S6, running them so soft it wouldnt matter, youd still have plenty of light. It would be an extra 80e but thats like 10g of swede-weed.
    2 boards: 160e
    1 Hlg185c1400 w dimmer, about 60ish i guess. With this driver you should be able to get 140w total with these boards which could be too much for your space so be sure to get a dimmer
    + Shipping, not sure how much.
    No heatsinks w need of drilling and building a frame, and your light is pretty much spread out over the whole cannopy. Also plenty of room to expand: w heatsinks and more powerfull drivers you should be able to do a m2 but with higher clearance between light and plants.

    Check out the boards from europe thread here in the led se tion for more info

    Edit: maybe wont fit as the boards are 400x280mm and your closet is 580 at its widest
    Last edited: Feb 8, 2018
    Moflow likes this.

    InTheValley Well-Known Member

    dang man, wanted to see your cob set-up. Im getting ready to do a 4 cob in a 2x2.

    good luck with the strips!

    Fawkes420 Member

    Hi there. Känner jag dig ?;)

    I've looked at these boards and they look nice. I just wonder about airflow. To have a solid board may be an obstacle since my air out take is on top and my (passive) inlets are at the bottom.
    My plan is to build a frame of wood, and then mount the strips on alu u-channel (also acting like heatsinks).
    The strip are 28cm long so i will make the alus 30 leaving 1 cm each side for attaching them to wood frame.
    When i mount them to frame i will leave 2.5 - 3 cm space between strips so air will be able to pass through (will be good for transporting heat from heatsinks too.)
    Rocket Soul and InTheValley like this.

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