Best light setup for yield 20×20 room

All opinions welcome

Forget room size. what is the tonnage or BTU rating of your air conditioner?

Got three smaller windows I plan on having open its usually 30 something 40 something degrees out assume that and a small ac should be fine maybe even just fans it's in a cold as basement already

Ceilings about 7 and a half feet

You can run up to about 6kW of lighting in that space I would say.
Two large extractors might pull enough fresh air with that ambient temp, and I guess bugs from outside are not much of an issue then too.
Your extractors will need to push a total of 3200 cubic foot per minute With a bit of headroom as the ratings on the side is for smooth bore round ducting.

Do not expect to grow great weed. It is easy growing mediocre weed. For the primo stuff, you want to ACTIVELY control temperatures and humidity day and night.

Running living soil in 50 GAl pots was hoping to run 12 and Scroggins the whole thing or half? And I was thinking 8 1k xxxl hoods or is that stupid lol my buddy does that in about a space the same size and pulls like 15 to 17 a harvest but then I've been looking into diy cob leds so now I wanted some RIU opinions lol

And ya I hear you I'm not looking for the primo primo just some good yield b -b+ stuff my living soil usually helps a lot with the quality too

With 7.5 Ceiling height, I’d run Air cooled magnum xxxl’s with 1000w single ended bulbs and decent 1000w digi ballast like Solis Tech or even Quantums. You don’t have the height for DE’s. You can do at least 4 rows of 3 fixtures each. With aisle space to get around

This room was 15x16 and I ran 10kw in the middle of summer in L.A 100+ temps with a 8000 btu window AC and 3 vortex 6” fans. The room was sealed and pulled 100f air through the hoods all day and still never got above 85f with a 20lb co2 tank lasting almost 40 days. If you had a 2 ton mini split or wall unit you’d be golden.

I like the setup there how are the yields your lights look slot sifferent then my buddies her took 8 xxxl hoods and made like a diy fixture for em and gets great results

Toohighmf said:

View attachment 4050668 This room was 15x16 and I ran 10kw in the middle of summer in L.A 100+ temps with a 8000 btu window AC and 3 vortex 6” fans. The room was sealed and pulled 100f air through the hoods all day and still never got above 85f with a 20lb co2 tank lasting almost 40 days. If you had a 2 ton mini split or wall unit you’d be golden.View attachment 4050667

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Now thats inspiring.

4 50 gals to a 1000W is about right (60 is about where the pot getting bigger doesn't really affect yield that much indoors)

What if I did 3 1k watts for each 4 50 gal setups cuz I'm going to have 12

Question. Does anybody manufacture a COB fixture that can be duct cooled?

The mean heat benefit to LEDs above HID is that the latter can do nothing about the heat it sends out in IR. it has to go out with the light. IN COBs, if someone is smart enough to design a proper housing, that 15% wasted heat energy will get sucked right off the heatsink and out the room.

To much heat? :/ or mad money lol

Jimmy Verde said:

I like the setup there how are the yields your lights look slot sifferent then my buddies her took 8 xxxl hoods and made like a diy fixture for em and gets great results

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Thanks! With elite genetics back in the day when this was done we got a P a light lol. Those are cool tubes with clear pbt plastic collars I swaged on to the tubes with a heat gun. 2 rows of 3 and 1 of 4 made 10kw the fastest room I ever built, hanging 3 lights at at time!

ANC said:

Question. Does anybody manufacture a COB fixture that can be duct cooled?

The mean heat benefit to LEDs above HID is that the latter can do nothing about the heat it sends out in IR. it has to go out with the light. IN COBs, if someone is smart enough to design a proper housing, that 15% wasted heat energy will get sucked right off the heatsink and out the room.

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Johnson grow lights maximizer is a 9 COB fixture in an air cooled reflector.

I seen someone on Facebook talking about baically same thing other day @ANC no clue tho I'd love to know... what's your opinion on cobs

Toohighmf said:

Johnson grow lights maximizer is a 9 COB fixture in an air cooled reflector.

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Oh oh oh

COBs are cool but I think quantum boards from HLG (same as Johnson grow lights)
Is brighter and more efficient. I’m about to test 9x HLG-550’s in a modified shipping container, which I’ll start a thread here about very soon.