COBs for stealth cab
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churchhaze
Well-Known Member
Vero 18 because vero 29 is too powerful at over 1A, which for the amount you'd underdrive it, you might as well get a cxa3070 3000k AB bin.
Aim for around 30-35W/sqft. Any higher and you will likely get bleaching.
Aim for around 30-35W/sqft. Any higher and you will likely get bleaching.
Yea it's not too big a space so I don't think I'd need much it's only 20 deep by 38x78 and I only ever have 2 plants. I was looking at the Cree cobs till I saw the Vero price. Now I just need to pick out everything else that's needed LOL.
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churchhaze
Well-Known Member
9 or 10 vero 18 3500k 80cri driven at 700mA would work well in an area like that. That's a total electric dissipation of 180-200W (about 20W each at 700mA). The cree cobs I think are supposed to be a few percentage points higher efficiency.
From what I understand, the vero 18 3500k 80cri have an efficiency of around 38% at 700mA, which is slightly better than HPS, and already reflected down.
You could use fewer cobs driven harder for a reduced startup cost, but the efficiency goes down as you run at a higher current.
From what I understand, the vero 18 3500k 80cri have an efficiency of around 38% at 700mA, which is slightly better than HPS, and already reflected down.
You could use fewer cobs driven harder for a reduced startup cost, but the efficiency goes down as you run at a higher current.
Do you really think I need 9 or 10. It's a small space. Couldn't I run fewer bigger ones and underdrive them to get better efficiency. I'm a noob to this as I have only done hid lights as pre made led just too expensive for what you get I'm my opinion.
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AquariusPanta
Well-Known Member
Corn on the cob?
Well there are the Vero 29's, which may be what your thinking of. Using those and running them at Churchy's recommended 700mA current could lead you to buying a total of 5-7, rather than 9-10 V18's.
The price difference between the the two models differs greatly. If your looking to run efficiently, I believe the Vero 18 is the better choice at $13 per COB, while the Vero 29 is $30 per. With the V18, running @700mA, your looking at around 19-23W. With the V29, running @700mA, your looking at around 26-29W.
Check em' out:
http://www.digikey.com/product-highlights/en/vero-series/51566?WT.z_Tab_Cat=Featured%20Products
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I'd rather go that route then buying 10 i may copy the thread for the gigantica diy As he is running 6 cree. It just seemed like overkill as I only have 2 plants.
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It's chip on board it's like super leds
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AquariusPanta
Well-Known Member
I'm currently running 2x V18's, @30W each, alongside a BlackStar 240W, 140W actual. All for a single lady.
Nice how do you like the blackstar. That's one of the premade I was looking into a while back. And to be honest I just want something that's equal to my 400w but more efficient. I'm looking at long term cost as opposed to up front cost.
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churchhaze
Well-Known Member
In general, when it comes to leds, the harder you run them, the less efficient they are, so there's a tradeoff between efficiency and startup cost.
If you're running a shitty brand combined with driving too hard, you may as well use HPS because the efficiency will be higher.
I fail to see how running the vero 29 at 700mA will be a lower startup cost than a vero 18 at 700mA. That's 31 dollars for a 25W lamp (1.24$/W dissipated). The vero 18 at 700mA is 13 dollars for 20W 0.65$/W dissipated. I switched from vero 29 to vero 18 specifically because I didn't want to buy more vero 29 with the intention of driving them below 1050mA. I'm not a rich man!
How would choosing the vero 29 and underdriving so much reduce startup cost? I don't know anyone who runs the vero 29 that soft yet. Sure, the efficiency would be better, but it would cost almost twice the amount to setup.
If you're running a shitty brand combined with driving too hard, you may as well use HPS because the efficiency will be higher.
I fail to see how running the vero 29 at 700mA will be a lower startup cost than a vero 18 at 700mA. That's 31 dollars for a 25W lamp (1.24$/W dissipated). The vero 18 at 700mA is 13 dollars for 20W 0.65$/W dissipated. I switched from vero 29 to vero 18 specifically because I didn't want to buy more vero 29 with the intention of driving them below 1050mA. I'm not a rich man!
How would choosing the vero 29 and underdriving so much reduce startup cost? I don't know anyone who runs the vero 29 that soft yet. Sure, the efficiency would be better, but it would cost almost twice the amount to setup.
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churchhaze
Well-Known Member
9-10 vero 18 at 700mA is not overkill. I calculated it based on the area of your cabinet. About 180-200W electric dissipation.
20W dissipation each at 700mA draw.
My point about the vero 29 being too powerful is that it might not be worth underdriving that significantly. The cree cxa3070 might be a better candidate for a larger array intended to underdrive that much rather than the vero 29.
20W dissipation each at 700mA draw.
My point about the vero 29 being too powerful is that it might not be worth underdriving that significantly. The cree cxa3070 might be a better candidate for a larger array intended to underdrive that much rather than the vero 29.
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churchhaze
Well-Known Member
I have a cabinet a little bigger than yours and just designed a light that I intend to use for just that.
(3) of these UFO killers. Each is (1) Driver and (1) heatsink per (4) vero 18
(Just to get the mind working so you can come up with a design)
(3) of these UFO killers. Each is (1) Driver and (1) heatsink per (4) vero 18
(Just to get the mind working so you can come up with a design)
churchhaze
Well-Known Member
Plus, the vero 29 has 4 screws while the vero 18 has 2 screws. You'll still be putting in the same amount of screws. 
AquariusPanta
Well-Known Member
Looking at your heatsinks, I can't help but wonder where you station the driver.
As it's been about a month or so for each of us using these V18's, how do you like em' so far Churchy?
churchhaze
Well-Known Member
The drivers get screwed to the wood frame of the cabinet, which is cheap 2x2 wood.
I haven't had a chance to use the 3500k vero 18 in flowering yet due to screwing up a round of clones. (none took root.. or they all took root and i neglected them... whichever....). 1 of the UFO killers is currently subbing as a veg lamp on the clones, and some new seedlings to replace dead clone attempts.
I've only had a chance to test 3000k vero 29 in flowering. It works well, but it's like a pan that burns everything in the middle. I run them at 1050mA, but originally wanted to run them at 1.4A.
1.4A on the vero 29 will burn ants. It's scary that 2.1A is the test current... and that it goes higher??? waat?
I haven't had a chance to use the 3500k vero 18 in flowering yet due to screwing up a round of clones. (none took root.. or they all took root and i neglected them... whichever....). 1 of the UFO killers is currently subbing as a veg lamp on the clones, and some new seedlings to replace dead clone attempts.
I've only had a chance to test 3000k vero 29 in flowering. It works well, but it's like a pan that burns everything in the middle. I run them at 1050mA, but originally wanted to run them at 1.4A.
1.4A on the vero 29 will burn ants. It's scary that 2.1A is the test current... and that it goes higher??? waat?
I made all my choices based on what a local guy said he seemed to know but guess not lol. He recommended underdriving a larger component.
What would you build for a veg/flower in that space would you run it one driver per cob or run them in series or parallel.
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churchhaze
Well-Known Member
A vero 18 at 700mA is technically underdriving since the test current is 1050mA. In general, your local friend is right. You will get better efficiency underdriving a larger array than overdriving a smaller one to get the same output power. If you ran a vero 29 at 700mA, you'd be underdriving even more since vero 29 has more strings for the current to go.