LED vs vertical HPS (PPF and other things)

Enigma

Enigma

Well-Known Member
ttystikk said:
No need for reflectors in a tent with reflective walls.

I think this gets to be a clusterfuck in a 3x3 but would work well in a 4x4, as this would allow for plant thickness on the panels.

Another way to deal with COB light pattern would be to actually aim them at the corners. This would give more even light distribution.
Click to expand...

The 4x4 suffers because of angular radiance, even the walls will have a difficult time reaching the corners.

Instead of having 8" of lateral growth we would have 15" which would be better, but it would present a problem on the sides. We could add a tube to make eight to compensate, but at that angle there would be a huge difference in growth than in the center.

If we supplemented with EBs we could make up the difference but drive up initial cost and running cost.

I'm running some trig on a meter tent. That might change everything.

:leaf:
 
Enigma

Enigma

Well-Known Member
@ttystikk

From my calculations we would have a usable lateral growth of 9.8", with the ceiling as the only other constraint.

With a meter tent everything seems to fit perfectly.

I don't know why I didn't think about using the circumference of the Earth to design my setup.

It only makes sense.

Fuck the Imperial System of Measurement.

:leaf:
 
JohnDoeTho

JohnDoeTho

Well-Known Member
Enigma said:
@ttystikk

From my calculations we would have a usable lateral growth of 9.8", with the ceiling as the only other constraint.

With a meter tent everything seems to fit perfectly.

I don't know why I didn't think about using the circumference of the Earth to design my setup.

It only makes sense.

Fuck the Imperial System of Measurement.

:leaf:
Click to expand...
Funny how everything works out so perfectly on the earth.
 
Enigma

Enigma

Well-Known Member
For shits and giggles, I decided what I could do with the same design using HID.

Turns out, in order to accomplish that I would need two 600W HID with cool tubes and ductwork. That would drive initial costs up.

I didn't do the numbers, but it seems the waste heat of HID, coupled with proper management, might wash with the cost of LED.

I've been waiting for this day for a decade, and I'm already behind everyone else.
 
Rahz

Rahz

Well-Known Member
I mistakenly gave you the PPFD for a 3x3' area. In a 3.5x4' area the PPFD would be just under 700. Depending on how much wattage you're putting on the sides you could use 6 cobs at 70w each and use two rows of three which would tone down the center intensity.

Anyway, with just 5 cobs at 70w each I think it would be easy to hit 20 zips. That's only 40 g/sqft in a 3.5x4. If you're thinking about similar wattage on the sides, 80 g/sqft is getting pretty tight but not impossible.
 
Enigma

Enigma

Well-Known Member
Rahz said:
I mistakenly gave you the PPFD for a 3x3' area. In a 3.5x4' area the PPFD would be just under 700. Depending on how much wattage you're putting on the sides you could use 6 cobs at 70w each and use two rows of three which would tone down the center intensity.

Anyway, with just 5 cobs at 70w each I think it would be easy to hit 20 zips. That's only 40 g/sqft in a 3.5x4. If you're thinking about similar wattage on the sides, 80 g/sqft is getting pretty tight but not impossible.
Click to expand...

How well do the V29C-SE fair with 1400 mA?

Would the 150 mm heat sinks need active cooling or to be replaced?

@Rahz
 
Last edited:
ttystikk

ttystikk

Well-Known Member
JohnDoeTho said:
Little bit of mushrooms I was convinced everything was based on circles. Because everything rotates full circle.
Click to expand...
Trip on Fibonacci while looking at fractals sometime. It's a religious experience.

I'm not Christian. I don't need to walk into a building full of dogma to see God in everything around me.

Einstein said something very similar.
 
Enigma

Enigma

Well-Known Member
Rahz said:
They will run in spec but not much below mfg recommendation. Also at 95 watts efficiency is dipping below 50%. 70w on those sinks is a much better combo.
Click to expand...

With the amperage increase I'd expect ~160 lm/W instead of ~180 lm/W?

I'm estimating from the data sheets.

@Rahz
 
nfhiggs

nfhiggs

Well-Known Member
ttystikk said:
No need to go that far; using an array of light sources evenly distributed over the target surface effectively accomplished the same thing. Further, since the lamps or chips are not just emitting light straight down but also at angle to the sides, you're getting cross illumination which effectively combats the effects of leaf shading.

Add a reflective surface such as white plastic sheeting around your array and the corners get as much light as the center does.

This is a big reason why people are seeing such huge increases in performance from LED lighting.
Click to expand...
Yes, the distributed arrays (like my strip light) are a move in that direction, but you still get significant fall off as you go down. Why stop at just illuminating from the top?
 
You must log in or register to reply here.
Top