Bars vs Boards

Prawn Connery

Prawn Connery

Well-Known Member
Lockedin said:
Hi P.C.

re: No heat sink --- how hard / soft are you driving them? Or does all that surface area act as a sink?
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I don't run Fotops. We designed our own boards – which I'm trying not to spam too much here – that have a similar LED layout (13-14mm spacing) on a board about half the size (415mm x 205mm). We run these boards at up to 150W per board without a heatsink when its cold, and up to 130W when it's warmer. So I'm basing the Fotop specs on the boards below, which can easily handle 240W+ per pair without sinks.

DoubleCombo1.jpg


There are other boards on the market that also have good LED spacing, such as the German Zeus Boards. The larger XT model in this photo has 308 Samsung LEDs over a 440mm x 285mm panel and is rated up to 140W without a heatsink. As you can see, a tent full of these boards would also provide very good coverage.

There are lots of different LED boards to choose from if you look.

1594659546631.png
 
Rocket Soul

Rocket Soul

Well-Known Member
Lockedin said:
Hi P.C.

re: No heat sink --- how hard / soft are you driving them? Or does all that surface area act as a sink?
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Weve run these extensively between 120-240w. 240w needs a bit of sinking, a alusheet with a couple of inches of lip is good. Maybe im more picky than Prawn. And it also depends on how much airmovement you have around. 3 of those did quite well over a 1.1x2m area, about 30w per foot.
Currently weve had 4 of them on 2 x 240 drivers on a 1x1.5m frame (about 5 feets wide) for a foot print about 1.7m wide.It did very well even though the intensity wasnt huge. We did about 2 pounds per light at 1.86g/w, about 27w per foot.

We also did 5 boards on 3 x 240 drivers over the same 1.1x2m section, this went really well with low hanging height and really good coverage. But light was so intense that it would almost allways burn off the top fan leaves; weird looking almost like senesence with purple yellow leaves, but it only opens up a bit to lowers.

One thing on these boards: if you have them running really low they emit almost no heat which may be a problem in winter, we had to put in cmh to warm the grow.

All in all, great to wok with for larger open area grows cause you minimize connection and wall losses.
 
K

kkookoo

Well-Known Member
Prawn Connery said:
Thank you. As I have repeated in this thread ad nauseam, just because you don't understand how a piece of software works doesn't mean it is any less legitimate. Anyone who knows how to use Dialux will reach the same conclusion.


Yes it is a simple argument. The better you can space your diodes, the more even the canopy. The closer you can put the LEDs to the canopy, the fewer wall losses there are. But the story doesn't end there . . .

You still need a certain amount of light to hit the canopy to be effective, so it's not just about light spread, but intensity also. And if you are not growing in a small space, then wall losses diminish exponentially as you increase your grow area.

Every time you double your room size, you effectively halve the amount of wall surface area (and wall losses, all else being equal).

Eventually you reach a point where wall losses become negligible compared to the total amount of light in the room.

So wall losses are not a major consideration in open-room and warehouse grows. You still need to be able to walk and work around your plants, so in a warehouse grow it is better to have your lights a little higher to allow access, and the overlapping light pattern means you don't lose much light by doing this. That's how bay lighting works.

By the same token, not everyone wants to keep their lights as close to the plants as possible because they don't want to be adjusting them every day.

In these cases, strips actually lead to more wall losses because they are closer to the walls in the first place. And that's why I said at the very beginning of this thread that it is "horses for courses". There is no "one size fits all".

Likewise, it is wrong to state "Led strips offer by far the best spread of light points and therefore the best light diffusion and thus light penetration" because that is not true in all cases.


Not necessarily. it depends on the LED layout of the strips and boards. Most strips pack their LEDs very close together in a line along the strip. Some boards space their LEDs quite far apart.

Here is a Fotop board
View attachment 4622856

Here is a Samsung F Series strip
View attachment 4622854

There is no way I am ever going to agree with you that if we place 3x Fotop boards in a 3'x3' or 1m x 1m (for example), that a similar number of Samsung strip LEDs is going to provide better coverage.

Why?

Because the Fotop boards (900mm x 280mm) will cover the entire roof of that tent and the LEDs will be evenly spaced at about 15mm between each and every diode, whilst the F Series strips will be in lines of tightly-packed LEDs that are only a few mm apart.

You have used Dialux, and so you know what I'm talking about.

Now look at it from a price perspective, and maybe things change . . . Or do they?

3x Fotop boards at US$80 have 2400 LEDs for $240

17x 560mm Samsung F Series strips are anywhere up to US$350+

Space them out over a 1m x 1m and I don't need Dialux to know which of the above configurations produces the more even spread with the fewest wall losses.

And let's not even talk about the amount of wiring required for those 17 strips vs 3x Fotop boards!

This is just one example – I could provide many more – of where "horses for courses" applies. No-one can sit behind their keyboard and categorically state that "strips are better" or "boards are better" because it depends on circumstance.

And that is my point.
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Well whatever lol it’s all good whatever solution works best.

Spread out the diodes as best as possible with minimal hot spots I guess is what I should have said
 
Prawn Connery

Prawn Connery

Well-Known Member
kkookoo said:
Well whatever lol it’s all good whatever solution works best.

Spread out the diodes as best as possible with minimal hot spots I guess is what I should have said
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It's all good. I was never arguing against strips – in many cases they are the best budget option. I was merely pointing out that some of the comments on here are not based on fact, or were criticising Dialux when they have no idea how it works. That obviously wasn't aimed at you.

Different strokes for different folks is all I'm saying.

kkookoo said:
You can just put a fan towards the boards they will run super cool
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Yes, we've run boards at up to 150W without heatsinks and merely blowing a fan across the top of them can reduce junction temperatures by 15-20C or more. The larger the board, the bigger the surface area, the faster it can dissipate heat into the atmosphere. If you want the best of both worlds, you add a heatsink and a fan. Most growers have fans running in their rooms anyway – or at least they should – so you will get the benefits of air movement anyway.
 
T

tired_druid

Member
Prawn Connery said:
My main issue with him is that he is never honest in his debates.

For example, here is what a High Light board looks like to scale in his 24" x 24" room. The High Light measures 16.3" x 8"
View attachment 4612104


Here is what two High Light boards look like to scale
View attachment 4612105\


And here is the light output of the strips
View attachment 4612107

There is no perfect light spread with strips. The red circles represent hotspots where the light is reflected very close to the source. The blue lines equate to roughly the elliptical light output from a strip. It is this way due to not only its shape, but the fact strip LEDs are placed very close together.

Here is a 2" F-Series strip. Note how closely the LEDs are placed. This forms a strong, thin light source that emits in the shape above.
View attachment 4612121

I know all this for two reasons. Firstly, I have measured strips with IES files using Dialux. Secondly, I have grown with both boards and strips.

Here is my old strip build.
View attachment 4612123

Here are the frames. I did not use double-row F-Series for this build because I got better light spread using two 24V single strips wired in series to run off a 48V driver. Also, these strips have their LEDs space further apart than the ones above. Note the spacing – it is similar to the spacing of the LEDs on a High Light board.
View attachment 4612124

I've built loads of strips. Now I build boards.
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this has been a great read, thanks everyone for the input. i dont know anything about led or building lights but those buds look quite average, lots of white hairs and no trichombes. They look kind of unhappy.
 
Prawn Connery

Prawn Connery

Well-Known Member
tired_druid said:
this has been a great read, thanks everyone for the input. i dont know anything about led or building lights but those buds look quite average, lots of white hairs and no trichombes. They look kind of unhappy.
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Hey mate, are you referring to this photo? What do you mean by the plants look "unhappy"? This was an early strip build (2018) under Samsung LM281B diodes with no UVA – unlike the High Lights I run now. The point of the photos I posted was not to show off the plants but to prove that I have grown with both strips and boards, so I have practical experience with both.


I can show you trichomes if you want – check out the thread in my link .
IMG_8427.jpeg

IMG_8377.jpeg
 
L

Lou66

Well-Known Member
I don't really get the discussion. If you space them correctly there shouldn't be any difference between boards and strips?

And strips are usually cheaper. So for small operations a motivated person can get a good setup for a cheaper price. The higher density of strips allows lower drive currents which increase efficiency.
 
O

Orblight

Well-Known Member
I can never find a definitive answer to this question so I'm about to find out.
Currently I run a 5x5 area with 3x 200w boards (sf2000s) that do quite well.
Next run in a few weeks I'm going to use a 10x 5 area with the 3x 200w boards on 1 side and a 700w bar style on the other side ( SE7000) not a perfect comparison since the bars are 100w more than my boards but I'm curious to see how it goes.
 
T

tired_druid

Member
Prawn Connery said:
Hey mate, are you referring to this photo? What do you mean by the plants look "unhappy"? This was an early strip build (2018) under Samsung LM281B diodes with no UVA – unlike the High Lights I run now. The point of the photos I posted was not to show off the plants but to prove that I have grown with both strips and boards, so I have practical experience with both.


I can show you trichomes if you want – check out the thread in my link .
View attachment 5200954

View attachment 5200955
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yes that is a little more appealing, is mid flower? whats going on with the plants they look a bit deformed at the top.
 
Prawn Connery

Prawn Connery

Well-Known Member
tired_druid said:
yes that is a little more appealing, is mid flower? whats going on with the plants they look a bit deformed at the top.
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You haven't grown many plants, have you?

EDIT: Maybe you think I'm being rude saying that, but when you have grown out many plants over the years you will know that you can't judge the quality of the smoke by the "look" of a plant. For example, I would take those "sick" plants you referred to earlier any day of the week over the ones I just posted. They have some really nice Haze genetics and the smoke (which I still have from the clones I kept) is better than anything else in my collection. When I bring it out at parties, people like you turn their nose up at it . . . until they smoke it.

Of course, if you had grown them, you would know that sativa doms are not as "frosty" as average indicas but pack a completely different punch. The high is usually much longer lasting, too.
 
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tired_druid

Member
Prawn Connery said:
You haven't grown many plants, have you?

EDIT: Maybe you think I'm being rude saying that, but when you have grown out many plants over the years you will know that you can't judge the quality of the smoke by the "look" of a plant. For example, I would take those "sick" plants you referred to earlier any day of the week over the ones I just posted. They have some really nice Haze genetics and the smoke (which I still have from the clones I kept) is better than anything else in my collection. When I bring it out at parties, people like you turn their nose up at it . . . until they smoke it.

Of course, if you had grown them, you would know that sativa doms are not as "frosty" as average indicas but pack a completely different punch. The high is usually much longer lasting, too.
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I would never assume what a person knows or doesn't know, especially when they have never met. I grew plenty of plants back in the late eighties, what triggered my interest again was all the new strains that are available and the visual appeal of the quality that is being produced on the medicinal scene. Not talking about genetics you have there just the health of the plant, id argue that the health of the plant is a key indicator to the quality of the flower it will produce. The flowers directly under the light are experiencing light stress, I can tell as the colas are deformed and by the amount of new white hairs its sprouting, while the middle buds appear to be able to be able to finish. My opinion comes from a career in horticulture where I have obtained an Advanced Technical diploma in horticulture and am currently, allbeit a mature one, a student studying a bachelor of science in botany.
Not trying to attack you pal, just offering an opinion. No need for the 'people like you' stuff, take it easy.
 
Prawn Connery

Prawn Connery

Well-Known Member
tired_druid said:
I would never assume what a person knows or doesn't know, especially when they have never met. I grew plenty of plants back in the late eighties, what triggered my interest again was all the new strains that are available and the visual appeal of the quality that is being produced on the medicinal scene. Not talking about genetics you have there just the health of the plant, id argue that the health of the plant is a key indicator to the quality of the flower it will produce. The flowers directly under the light are experiencing light stress, I can tell as the colas are deformed and by the amount of new white hairs its sprouting, while the middle buds appear to be able to be able to finish. My opinion comes from a career in horticulture where I have obtained an Advanced Technical diploma in horticulture and am currently, allbeit a mature one, a student studying a bachelor of science in botany.
Not trying to attack you pal, just offering an opinion. No need for the 'people like you' stuff, take it easy.
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You quote one of my posts with the photo below and say: "those buds look quite average, lots of white hairs and no trichombes. They look kind of unhappy."

Really? You don't come across as a botonist to me. You come across as a troll. Regardless of what you think of the genetics, these plants are not "unhealthy".

Claim to be anything you want, mate, but I don't see your plants.

1664173817397.png
 
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