cdgmoney250
Well-Known Member
FoshizzleSo im guessing about 600 watts of cob can replace 1000 watts of hps?
FoshizzleSo im guessing about 600 watts of cob can replace 1000 watts of hps?
It can...So im guessing about 600 watts of cob can replace 1000 watts of hps?
Nice break down.It can...
15 CXB 3590 3500k @ 37w (1050ma) = 555w x .61 ( 61% efficiency) = 338.5 initial PAR watts x .9 for reflector/wall loss = 304.6
Now divided by let's say 4 x 4 so 16sf = 19.04 PAR watts per st.
Now multiply that times 4.65 umol = 88.55
Now multiply that times 10.7 ( feet in a meter squared) = PPFD of 947.5...
Not to shabby for 600 watts and those 15 cobs can be evenly spread over your area and even can be passively cooled. This is what's been showed me by many here (Supra, GreenGenes, Growmou5e) and many more. The main reason I'm building my own light...
Only the light spread is much more uniformI built my first cob fixture. 4 cxb3590 cd bin @ 50 watts each, passively cooled on two 5.88"x20" heatsink us profiles. Each cob is centered 5" from the ends with 80 degree lenses, so they have 10" of heatsink. The two heatsinks are spaced evenly on aluminum angle so each cob covers 1 sq ft In a 75 degree room, my heatsink comes in at 85 degrees on the edges closest to the cobs. The metal lens holder measures 95 degrees. The canopy temperature measures 78 degrees 8" from the lenses(which is probably closer than anyone would want). These readings were taken with a quality laser thermometer, not a $15 piece of shit. I have a desktop thermometer sitting on top of the heatsink, and it reads 77 degrees. I know this isn't scientific, but these things run cool, and the light is very similar to hid in that it lights up the whole room.
Isn't the hotspot of HID 2000K bulbs @ about 3ft 1100ish? I can't find a PPFD chart for HPS off hand. It probably varies by reflector. Maybe it's more, but my understanding was that I was getting really really close to HID numbers on a third of the energy and a fraction of the heat.It can...
15 CXB 3590 3500k @ 37w (1050ma) = 555w x .61 ( 61% efficiency) = 338.5 initial PAR watts x .9 for reflector/wall loss = 304.6
Now divided by let's say 4 x 4 so 16sf = 19.04 PAR watts per st.
Now multiply that times 4.65 umol = 88.55
Now multiply that times 10.7 ( feet in a meter squared) = PPFD of 947.5...
Not to shabby for 600 watts and those 15 cobs can be evenly spread over your area and even can be passively cooled. This is what's been showed me by many here (Supra, GreenGenes, Growmou5e) and many more. The main reason I'm building my own light...
Here is a breakdown of hps 1000w systems done by Growershouse, great shop by the way...Isn't the hotspot of HID 2000K bulbs @ about 3ft 1100ish? I can't find a PPFD chart for HPS off hand. It probably varies by reflector. Maybe it's more, but my understanding was that I was getting really really close to HID numbers on a third of the energy and a fraction of the heat.
This breaks it down so so well.
Oh wow... Wow... And yeah, I got all my Kessils from them, great deal!Here is a breakdown of hps 1000w systems done by Growershouse, great shop by the way...
http://growershouse.com/blog/best-indoor-grow-light-test/
that's the best way to do it. unbiased towards lamp systems that have better or worse light distribution.My point is that those PPFD matrix tests are done without reflective walls. They hang a light over a piece of paper in a very large dark room. So every bit of light that would normally have reflected off the walls is not measured at all in those tests. That's a huge amount of light gone. Especially for 1000W HPS fixtures which are generally quite high above the canopy. I would guess they measure at best half the light coming from those fixtures.
The problem I see with testing using walls is, what distance do you use to walls, and what type of wall?that's the best way to do it. unbiased towards lamp systems that have better or worse light distribution.
any system that relies on reflective walls as a large proportion of its light loses a lot of that because of reflection losses.
yes absolutely also...The problem I see with testing using walls is, what distance do you use to walls, and what type of wall?
Both of those will ad their own variables
Ive seen people talking about the Bml. Any full grows on them? What were the results?yes absolutely also...
Consider testing of a BML spyder versus an watt hps. BML spyder goes to extreme efforts to provide a nice uniform distribution without relying on walls\sides\reflective tents.