COB spacing for 2x4

[kushedy]

I built a couple of panels using 4 cxb3590's per panel a while back & spaced them out so that when hung in a 2x4 the cobs would be centered in each square foot.

Mathematically this seemed to be the best layout but in practice I get a hot spot down the center of the 2x4 so I'm considering a rebuild to get a better light spread.

I do remember seeing a thread a while ago where someone discussed this & talked about placing cobs closer to walls to avoid a cross over from each cob creating hot spots but, I can't find that thread when I search.

Can anyone school me on the current train of thought on cob placement?

 

[devile]

May I know what chips brand your COB used? I am using Mars COB, Cree chips, no heat problem at all

 

[Rahz]

Can anyone school me on the current train of thought on cob placement?

I think 1 cob centered per foot is pretty good at the right intensity and hanging height. If the average PPFD is in a good range the plants can handle hot spots as long as they aren't extreme. Raising the cobs and moving them out both cause more wall loss. If anything you might try spacing the panels off center so there's an extra couple inches between them.

 

[kushedy]

May I know what chips brand your COB used? I am using Mars COB, Cree chips, no heat problem at all

When I say hotspots, I don't mean actual locations where its extra hot temperature wise, I'm referring to locations in the 2x4 where the lux measurements are substantially higher than say the edges of the 2x4 due. This in my case appears to be the centre of the grow as presumably the light from 2 cobs is meeting in the middle the entire length of the gtow area & causing a higher intensity.

 

[kushedy]

I think 1 cob centered per foot is pretty good at the right intensity and hanging height. If the average PPFD is in a good range the plants can handle hot spots as long as they aren't extreme. Raising the cobs and moving them out both cause more wall loss. If anything you might try spacing the panels off center so there's an extra couple inches between them.

Thanks for your response. Yes, there definitely needs to be more of a gap between the cobs that are closest to centre going up the 4ft length of the grow. Even with a 30cm gap between them their dispersal of light seems to be combining & pushing the intensity up in the middle.
I guess I’ll have to re-build them from rectangular panels into 4ft long beam type panels. That way I can adjust the distances on the fly a little easier.