Understanding COB vs HID

Olive Drab Green

Well-Known Member
"if" if does, yes of course you can. give or take depending on efficiency you need about 100 cob watts to apply 900 ppfd to a 18x18 area, and consequently ~300W of cobs to apply 900 ppfd to a 54"' x 18" area
going back to the timber link you posted, with all due respect to dan/timber, listing "1013 ppfd" as a spec of the light is completely meaningless. assuming the 466 umol/s PPF figure is indeed accurate, to apply 1013 ppfd to an area you need to control that area to a size of 466/1013 = 0.46 sq. meter = 4.95 sq ft = 27" x 27"

PPFD vs PPF can indeed be confusing
And it does specify 5 square feet/0.465sq.m @18”. I had initially missed it.
 
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Olive Drab Green

Well-Known Member
math = factual
your conclusion that the math i presented supports the premise of your original post= false logic

i dont have time to go round and round with someone who cannot admit they were wrong, sorry.
I’m not saying my original post is accurate, just that my PPFD is correct. I was off a factor with my original post. But electroluminescence does explain the efficiency difference, even if it isn’t as much as I originally had said.
 

Olive Drab Green

Well-Known Member
Look, I already said I have no problem admitting I was wrong, but you also did essentially prove part of what I said to be right. I’m just saying. It’s here on this thread.
 
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