First time DIY Cob, how did I do?

I have a 4x4 flower only tent that I have yet to purchase a light for. After hours upon hours of research, I have a build im somewhat confident with, but can anyone more experienced than me give it a check and tell me if itll accomplish my goals? Obviously there is more to it like wiring, heatsinks, aluminum, etc, but Im just wondering if the cobs/driver combo is compatible and will do well in a 4x4.

Build:

12x Vero 29 Gen7 Type D
2x Meanwell HLG-320H-C1400

My only other question would be if I can get away with using 8 Vero 29s instead of 12 for a 4x4? Im not sure if 12 is overkill.

The better question would be can you get away with using 640 watts in a 4'x4' and not how many cobs you are running. The answer would be no, this is not overkill and pretty much gives you an optimal amount of juice to power your tent. Some would prefer more (the psycho's) and some would prefer less (the misers) but most will probably find 640 watts just fine

Use this type of layout.
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Sorry the formatting messed up my design. It's a 3-2-3 config with the middle row of cobs being centered evenly.

Danielson999 said:

The better question would be can you get away with using 640 watts in a 4'x4' and not how many cobs you are running. The answer would be no, this is not overkill and pretty much gives you an optimal amount of juice to power your tent. Some would prefer more (the psycho's) and some would prefer less (the misers) but most will probably find 640 watts just fine

Use this type of layout.
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Sorry the formatting messed up my design. It's a 3-2-3 config with the middle row of cobs being centered evenly.

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So just to be clear then, 8 Veros would be fine for a 4x4 with that layout? Id like to save the money and use 8 if possible.

happysadfacee said:

So just to be clear then, 8 Veros would be fine for a 4x4 with that layout? Id like to save the money and use 8 if possible.

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I hear you. I went through the same issue and I'm sure lots of guys do. Cobs aren't cheap and we'd all love to be using 24 cobs in a 4'x4' but it just costs too much. There are plenty of guys around RIU using 8 or 9 cobs in a 4'x4'. Just make sure you get the right amperage to run the cobs at the wattage you'd like.

Danielson999 said:

I hear you. I went through the same issue and I'm sure lots of guys do. Cobs aren't cheap and we'd all love to be using 24 cobs in a 4'x4' but it just costs too much. There are plenty of guys around RIU using 8 or 9 cobs in a 4'x4'. Just make sure you get the right amperage to run the cobs at the wattage you'd like.

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Awesome, thanks for the help. 36v at 1.4 amps should be 50 watts a cobb give or take 5 ish?

Danielson999 said:

I hear you. I went through the same issue and I'm sure lots of guys do. Cobs aren't cheap and we'd all love to be using 24 cobs in a 4'x4' but it just costs too much. There are plenty of guys around RIU using 8 or 9 cobs in a 4'x4'. Just make sure you get the right amperage to run the cobs at the wattage you'd like.

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I use 3-4 in a 5x2. Works perfectly.

happysadfacee said:

Awesome, thanks for the help. 36v at 1.4 amps should be 50 watts a cobb give or take 5 ish?

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I believe you'd want the HLG-320H-C2100 to put your cobs max around 80w each. You can dim with either an A type (dial on driver) or B type (get your own dimmer).

Danielson999 said:

I believe you'd want the HLG-320H-C2100 to put your cobs max around 80w each. You can dim with either an A type (dial on driver) or B type (get your own dimmer).

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Agreed.

My last DIY flower light was 8 CXB 3590's covering half a 5x9 tent but the grow area itself on that side was 4x4 thereabouts. I made two separate (4) COB bars and ran each bar off of a MW HLG320-2100B as suggested above. I was running khatod lenses on them as well with the drivers remote mounted. The lights covered the area just fine with no complaints. Those COB's were 3K 80 CRI. The Vero 29's were not out yet when I built that light or I would have gone that way.

All that being said I would go with Citi 1812's or 1818's if buying COB's for a build again today, a lot less money involved to build the same light using the citi's. I am liking my Citi's much better than I did my Cree's, not sure what it is yet........................

You could also lower your cost by not pushing them as hard with the 320W driver which cost considerably more than the other MW drivers. I'd be looking for a driver to push the COB's at about 50-60W per COB as efficiently as possible. A properly paired 1050mah driver should do the trick for this.

Just my $0.02
YMMV

I use 5 in a 4x4 and it works good. Not great, but good. About to upgrade it to 9 myself. I think 5-6=minimum 7-9 good middle ground, 10-12=high light and over 12 @ 50w just gets insane and would require CO2 to be useful.

Thanks everyone for the input. For what im comfortably with spending I think 8 cobs at 2100ma would do the trick. 640 watts give or take at the wall if im not mistaken, and adequate usable light to the plants for a 4x4 4-6 plant grow.

If anyone cares to answer, are 3k 80 CRI the most recommended for a pure flowering space?

I believe the 3k 80 CRI is the accepted norm for flower. I use them.
For your consideration. Netherfly's setup for a 4x4. https://www.rollitup.org/t/12xcxb3590-passively-cooled.898631/
Myself, I don't use a 4x4 tent, though, I can say that bars of 4 COBs each works great. My rack covers roughly a 4x6 + space nicely. The rack is 6'x3', supporting 5 bars of 4 COBs each.
Fortunately, as a DIYer, you can add/modify your setup as you go along. You could go w/8@2100ma for the first grow and modify accordingly for the next.
Will say, though, you won't be disappointed. From my first to current (pics below) excellent quality of buds. Frosty and dense. Oh, important to lollipop, light canopy penetration not like HPS.
Something to consider.
Success w/ya grow!!!

People are used to quoting spectrums for Cree and Citi cobs typically but Vero are not quite the same. As you can see in the graph, 3000K is going to give you 100% flower power but if a person were wanting to use the lights from veg to flower, you would still be getting almost 90% of the power in flower with 4000K but also 100% of the veg power compared to only 55% of veg power with 3000K.
Something to consider anyway. 4000K makes a great all-round spectrum with Vero 29 cobs.

You got to remember that every one of those peaks for each and every K/cri combo will have completely different output at their "relative spectral power distribution". We need these graphs redone with actual spectral power.

nevergoodenuf said:

You got to remember that every one of those peaks for each and every K/cri combo will have completely different output at their "relative spectral power distribution". We need these graphs redone with actual spectral power.

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Both the 3000K and 4000K in the graph are the 80cri versions.

Doesn't matter, each line (kelvin) only represents 100% output of that combo. It might only be a little, but you can't assume they have the same max output. I think @Malocan can tell me if I am wrong or not.

He might even be able to give some graphic examples.

nevergoodenuf said:

Doesn't matter, each line (kelvin) only represents 100% output of that combo. It might only be a little, but you can't assume they have the same max output. I think @Malocan can tell me if I am wrong or not.

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3000K are only available in 80 and 90cri that I know of. You'd be taking an 18% (approximately) hit in output by using 90cri.

Output of what, lumens?

Yes of course, sadly LM/W is the only rating they give on the Bridgelux site.