LED vs vertical HPS (PPF and other things)

Enigma

Well-Known Member
Better still, use EBs.

That could cut the diameter nearly in half!

Hell yea!

That's it, next project.
 

ttystikk

Well-Known Member
I'm sure a cylindrical space could be built with COBs. Maybe a hexagon would be the most efficient shape in that case, there would be a minimum diameter of about 10', in my estimation.

That would be one bad ass op.

In-fact, I'm going to start running some numbers...
Round silos don't fit well in square rooms. That's why my vertical COB LED array is flat.

The only reason for the cylindrical shape was the omnidirectional output of the bulb. In all other respects the layout is a pain in the ass; there's not enough room inside to work, doesn't fit well in square rooms, multiple silos don't fit together efficiently.

Rows are better and LED lights let you do it, so why not?

Do run the numbers and share what you come up with. When I did it, the answer I came up with is what you see in the pics I've been posted.
 

MMJ Dreaming 99

Well-Known Member
The thing is that with an HPS bulb you lose between 18% and 25% on the reflector. So when you remove that reflector and use a bare bulb indeed your yield per W will go up.

Still, the best single ended HPS bulbs will produce 1.8 to 1.9umol/s/W. A COB will easily produce 2.3 to 2.4umol/s/W. So with COBs (or similar SMDs) you'd have around 25% more light from the same amount of electricity used by HPS.

I was getting 1 to 1.1g/W with horizontal double ended HPS grows and with COBs I moved up to 1.4 to 1.5g/W. That's with older model COBs, current ones are already 10% to 15% more efficient.
Which older model COBs bro? How many COBs needed to match DE HPS? Any idea of the COB watts at the plus versus 1000 watts of HPS? Thanks.

I have been looking for someone who actually had COBS or a QB setup that beat SE or DE HPS in yield. Awesome info. Thank you.
 

Enigma

Well-Known Member
Which older model COBs bro? How many COBs needed to match DE HPS? Any idea of the COB watts at the plus versus 1000 watts of HPS? Thanks.

I have been looking for someone who actually had COBS or a QB setup that beat SE or DE HPS in yield. Awesome info. Thank you.

Search the forums.

I did.
 

Prawn Connery

Well-Known Member
Silo growing is a no-brainer with bulbs - though I still think there may be efficiencies to be gained with vertical LED, as there is always ambient/stray light to be captured. However, at this stage, it is just a hypothesis . . .

My old vertical box was 4'x4'x6' tall. Inside were 2x 600w HPS inline bare bulbs with a floor fan blowing up the middle and a 2' diameter cage (trellis, if you like) around the fan. That gave me an inside area of about 38 square feet (2' x 3.142 x 6'). The outside area - the perimeter of the plants - was closer to 75 square feet (4' x 3.142 x 6').

That was from a 16' square footprint. While you could argue round silos don't fit square rooms, four round silos in a square room allows you to walk between silos to work on your plants, while there is over-lapping light from each silo (the light that escapes through the vertical canopy). That is exactly the floor plan I would use for a commercial grow if numbers weren't an issue (24 plants flowering at any one time).

Because plant numbers are an issue for this next commercial grow, I came up with 3 silos arranged in a triangle with a total of 10 plants arranged in such a way that there are five plants around each silo (though some plants share silos, and are lit from both sides). It's hard to diagramtise, but it would have looked a little bit like this (it's easier if you take 10 coins representing plants "X" and arrange them around three larger coins representing lights "O".

.................X.......X
.....................O
.............X......X.......X
........X...O.....X.......O...X
................X..........X

Such an arrangement would have meant moving plants around at different stages of flowering - it would have
been a perpetual grow, where one plant would mature every six days - which was all a bit too much work for my friend, who has now decided to stick with a horizonal set-up.

The reason we were preparing to go to so much trouble for this grow was to keep plant numbers within a certain legal limit (still illegal, but low enough not to transgress the next offense category should he get busted, which would have meant the difference between a fine and jail time), while trying to maximise yields at the same time. We have a funny law that allows for quite a large amount of harvested product, but only small plant numbers before you start looking at jail time.

Growing is all about working within parameters - be it space, energy usage, or plant numbers and jail time!
 

wietefras

Well-Known Member
Silo growing is a no-brainer with bulbs - though I still think there may be efficiencies to be gained with vertical LED, as there is always ambient/stray light to be captured. However, at this stage, it is just a hypothesis . . .
I agree. There is still a lot of light hitting the walls with flat vertical. Besides, I'd rather do horizontal scrog than vertical flat trellis.
 

wietefras

Well-Known Member
I'm sure a cylindrical space could be built with COBs. Maybe a hexagon would be the most efficient shape in that case, there would be a minimum diameter of about 10', in my estimation.

That would be one bad ass op.

In-fact, I'm going to start running some numbers...
Indeed. Either COBs or strips. Just position the plants along a circle in a square room, light in the middle and go. I calculated that I could almost double the "growing area" in the same floor space and cut out most of the wall losses. Or cut the height of the grow room in half and still have the same size of "growing area".
 

Enigma

Well-Known Member
I agree. There is still a lot of light hitting the walls with flat vertical. Besides, I'd rather do horizontal scrog than vertical flat trellis.

There is more surface area in a square shape that a circle one. Take the square away and flatten it.

The numbers show @ttystikk vertical is the most efficient use of his space and lighting. If you run the numbers you will agree 100%, I did.

Light hitting walls? That is either strain or growing technique.

I've seen plenty of defoliated grows that had light "leaking" to the bottom in Scrog and otherwise.

You don't like his setup because.. you just don't?

That doesn't make for a solid argument.

To each their own.

:leaf:
 

wietefras

Well-Known Member
There is more surface area in a square shape that a circle one. Take the square away and flatten it.
No, that's just a couple of separate flat verticals and it would be completely impossible to actually run that way and reach the plants from all sides. A circle I can turn around.
 

Enigma

Well-Known Member
No, that's just a couple of separate flat verticals and it would be completely impossible to actually run that way and reach the plants from all sides. A circle I can turn around.

A cylinder 3' in diameter 4' tall has less surface area than a rectangle 12' long, 4' tall.

There is more potential in a flat surface over curved ones using LED, HID is the opposite.

Using a square fixture one could easily cover a square using LED, they same could be done with a HID, but the cylinderical setup would be more efficient.

I'm not concerned about lighting the plant on all sides, if I was I would grow outside.
 

wietefras

Well-Known Member
Using a square fixture one could easily cover a square using LED,
You cannot light up all 4 walls with one fixture, You'd have 4 sides which would be in each others way. Besides, the size of the lit up square is then also limited by the depth of the plants and the distance of the lights to the plants and you'd end up with pretty much a half sized square to the floor size and you'd lose the corners too. So in fact it's completely impossible to do what you said unless you end up with a vertical scrog with a light pole in the middle. Which would be a cylindrical vertical. Yes I would like that.

You really didn't calculate anything. You have some made some assumptions which in practice just wont work.

What you realistically could do if you insist on vertical scrog is have two vertical scrogs back to back. It would be an annoying squeeze to get that in the same tent and the only thing you'd save then is a bit of floor space. I'm also not looking to double my wattage so a single vertical would be my only option and then I'd really gain nothing.

Moreover, I'd still have the same amount of wall losses as with a regular horizontal scrog. Floor space is the least of my problems and a horizontal scrog is a lot easier to do than a vertical one. So there is zero benefit in that for me and I'd rather do a horizontal scrog.

As @Prawn Connery was also trying to tell you, a circular vertical can significantly increase efficiency. Mostly because it decreases the "wall" losses. In fact it reduces that to one quarter of a horizontal or vertical flat scrog for comparable grow area. You probably lose 20% of the light on the walls, so you'd get 15% more light on the plants with a cylindrical vertical. That would be an actual benefit to me.
 

Enigma

Well-Known Member
You cannot light up all 4 walls with one fixture, You'd have 4 sides which would be in each others way. Besides, the size of the lit up square is then also limited by the depth of the plants and the distance of the lights to the plants and you'd end up with pretty much a half sized square to the floor size and you'd lose the corners too. So in fact it's completely impossible to do what you said unless you end up with a vertical scrog with a light pole in the middle. Which would be a cylindrical vertical. Yes I would like that.

You really didn't calculate anything. You have some made some assumptions which in practice just wont work.

What you realistically could do if you insist on vertical scrog is have two vertical scrogs back to back. It would be an annoying squeeze to get that in the same tent and the only thing you'd save then is a bit of floor space. I'm also not looking to double my wattage so a single vertical would be my only option and then I'd really gain nothing.

Moreover, I'd still have the same amount of wall losses as with a regular horizontal scrog. Floor space is the least of my problems and a horizontal scrog is a lot easier to do than a vertical one. So there is zero benefit in that for me and I'd rather do a horizontal scrog.

As @Prawn Connery was also trying to tell you, a circular vertical can significantly increase efficiency. Mostly because it decreases the "wall" losses. In fact it reduces that to one quarter of a horizontal or vertical flat scrog for comparable grow area. You probably lose 20% of the light on the walls, so you'd get 15% more light on the plants with a cylindrical vertical. That would be an actual benefit to me.

You need to do some math, then you would understand and agree.

Cylindrical works with HID, not LED. It is because HID is 360° and COB is more like 160° usable.

Reaching the corners would be no problem for COBs.

You could do it rectangular, but it would be much more efficient to do it the way @ttystikk is doing.

Vertical grows benefit greatly from a trellis.

Scrog is vastly different from from vertical, the only similarity is the trellis.

Your calculations are completely wrong about light coverage between horizontal and cylindrical.

The funny thing is, you don't even know the most efficienct shape for vertical HID.

I doubt you'll ever figure that one out on your own.
 

wietefras

Well-Known Member
You need to do some math, then you would understand and agree.
I did the math and therefore I know you are full of it. And yes vertical or horizontal scrog are in fact the same.

Cylindrical works with HID, not LED. It is because HID is 360° and COB is more like 160° usable.
For HPS it works even better because of the lack of reflector needed yes, but for Leds you still cut out the wall losses as I already explained. That can give you 15% extra light too.

Anyway, sorry, but you really are a waste of time. I don't care about digging through your bro-sience. I'd rather talk to a vertical wall.
 

Enigma

Well-Known Member
I did the math and therefore I know you are full of it. And yes vertical or horizontal scrog are in fact the same.

For HPS it works even better because of the lack of reflector needed yes, but for Leds you still cut out the wall losses as I already explained. That can give you 15% extra light too.

Anyway, sorry, but you really are a waste of time. I don't care about digging through your bro-sience. I'd rather talk to a vertical wall.

One grows along the trellis, the other grows through it.

With vertical you keep the buds on the inside and the leaves on the outside.

Show your maths.

Don't give me Bro-Science.

Based on Maths, cylindrical LED is inferior to panel LED.

It is the opposite for HID.
 
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