Max. Efficiency set up (100+ Cree cxb3500 CD @350-700ma Passive)

Herbal_Essence said:

Thanks, nice to see you again!
It turned out to be decent. the second deleaf I did at day 28 was overkill I think, but even than, I still yielded my average.
so in my opinion, It doesn't really matter. but it does improve light penetration and airflow.
so I'll keep doing the usual thing, plucking leaves here and there where it seems like it's "needed".


I can spread the light more but I still want this amazing spread if I can afford it.
so Im leaning towards just dimming the light's rather than using less bars...
am I missing something?


I'm doing 10 bars 10 cobs per bar

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Airwalker16 said:

So 10 CXB cobs on a 48"/4' 5.886" profile extruded heat sinks. At 700ma, it shouldn't be all that hot bit that's a lot of cobs on a single HS. You don't plan on any fans? At all?

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Herbal_Essence said:

dude, not only you cannot read or count you also came up with your own measurements for my heatsink. nice job! xd

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topcat said:

Any idea when the new bins are hitting the market

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Herbal_Essence said:

Thanks, nice to see you again!
It turned out to be decent. the second deleaf I did at day 28 was overkill I think, but even than, I still yielded my average.
so in my opinion, It doesn't really matter. but it does improve light penetration and airflow.
so I'll keep doing the usual thing, plucking leaves here and there where it seems like it's "needed".


I still want this amazing even light spread if I can afford it.
so Im leaning towards just dimming the light's rather than using less bars...
am I missing something?


I'm doing 10 bars 10 cobs per bar

Click to expand...

BuddyColas said:

Thanks for the update. No, you're not missing anything. 100 cobs over about 4 square meters...or about 25 cobs per square meter...everyone would like that! Not many can afford that. I think it will be very efficient and a super even ppfd across the canopy. Look forward to seeing what it looks like built, AND particularly how productive it is.

Doing a bit of math here, I am running at a coverage of about 10 cobs a square meter. At 8" above the canopy and bare cobs my ppfd readings are 700ish and run about +/- 15% across the canopy. Yours should be real even and you can dial it down to whatever you want. I'm on my 3rd grow under the 3500K cobs and I have never grown better more productive plants. I wish you well on your build.

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Greengenes707 said:

Awesome build idea...just the idea itself needs to be done for the hell of it...then you can break it up into more cost effective lights. I liked your old setup with cheap gear...this could blow your mind.

Don't worry about new bins...they aren't going to be orderable for at least 6 months was the latest word. People just heard about them a little bit ago and are blindly infatuated by them already. And when they do come out...you will 95% not be able to tell the difference in yield or anything, even over a year of averaged out runs. Also, many CD's are currently almost DB's...just a few lumens behind, meaning they are more consistently coming in at the top end of CD bin. I expect that the new DB's will have more that fall into the lower end of the bin for the first bit of production. A CD could be just as good as a DB in some cases...or the opposite, and you get a steroided out DB and a weak CD and the gap is the biggest possible.
Everyone on here talks based on typical figure in the data sheet. But when thinking about the world and it's imperfections...not everything is so clear black and white as a data sheet.

Good luck, I'll be watching this one for sure!

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Herbal_Essence said:

I'll be sure to post some pics of that beauty!
and the final results ofcs

what in your opinion is the ppfd to shoot for if gr>watt is the main goal?

also, can you please estimate how high can we go efficiency wise?
for example, if with 700ma (~25W per COB) we are @ ~64% efficienct
were will we be with 350ma or even lower?

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Greengenes707 said:

Don't worry about new bins...they aren't going to be orderable for at least 6 months was the latest word. People just heard about them a little bit ago and are blindly infatuated by them already.

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Greengenes707 said:

And when they do come out...you will 95% not be able to tell the difference in yield or anything, even over a year of averaged out runs. Also, many CD's are currently almost DB's...just a few lumens behind, meaning they are more consistently coming in at the top end of CD bin. I expect that the new DB's will have more that fall into the lower end of the bin for the first bit of production.

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BOBBY_G said:

bummer but thanks for the update



i kinda guessed that would be the case, theres no magical 8% efficiency jump, more of a scatter plot of yields over time

@Greengenes707 , are you seeing the newer gold-logo 3500Ks performing any better than the older black logo ones?

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Herbal_Essence said:

I have started mounting the drivers to the sides of the heatsink with thermal paste so they will become as one unit
and I will be adding one 14 inch air flow fan to the center of the heatsink right next to the driver. should be very good.

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Herbal_Essence said:

its a mess now in the process...
getting ready

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