Question about strip builds

wietefras

wietefras

Well-Known Member
The point is that you are presenting this and urging people to follow your great example (which it isn't) and only now you are telling us that you are only doing this because you want to have a sub-optimal solution on purpose!?!?!? Yet I'm the crazy engineer for pointing out that it's sub-optimal?

People who claim that you get a hot spot in the center under led strips simply don't understand what a hot spot is. A hot spot is an area with very high light intensity relative to the average surrounding light. Usually only when detrimental to the growth of the plants in that area or at the very least outside of a tolerated range.

There is no such thing with led strips unless you hang the fixture extremely close to the plants (ie less than a few inches away).

Just a bit more light does not make it a hot spot. Especially not one which needs fixing.

Everything within 20% of average PPFD is fine. Trying to improve uniformity beyond that simply results in more light wasted with overall less yields.

BTW I know this is one of those weird engineer things again, but if you want less light on your plants, how about dimming instead of wasting light on walls and walkways?
 
Airwalker16

Airwalker16

Well-Known Member
wietefras said:
The point is that you are presenting this and urging people to follow your great example (which it isn't) and only now you are telling us that you are only doing this because you want to have a sub-optimal solution on purpose!?!?!? Yet I'm the crazy engineer for pointing out that it's sub-optimal?

People who claim that you get a hot spot in the center under led strips simply don't understand what a hot spot is. A hot spot is an area with very high light intensity relative to the average surrounding light. Usually only when detrimental to the growth of the plants in that area or at the very least outside of a tolerated range.

There is no such thing with led strips unless you hang the fixture extremely close to the plants (ie less than a few inches away).

Just a bit more light does not make it a hot spot. Especially not one which needs fixing.

Everything within 20% of average PPFD is fine. Trying to improve uniformity beyond that simply results in more light wasted with overall less yields.

BTW I know this is one of those weird engineer things again, but if you want less light on your plants, how about dimming instead of wasting light on walls and walkways?
Click to expand...
Bruh, don't take offense. He's clearly not coming at you or anything. Just stating what he's doing. Your information is very useful and I'm sure it will enlighten more people to come that may read this.
 
projectinfo

projectinfo

Well-Known Member
Airwalker16 said:
Bruh, don't take offense. He's clearly not coming at you or anything. Just stating what he's doing. Your information is very useful and I'm sure it will enlighten more people to come that may read this.
Click to expand...
Lol this is whats working for me at the moment, ive had burns in the middle. You cant deny that.

In this situation, this is what helps uniformity.

Yes i could re arrange my entire setup and put up reflective walls and re arrange my light spacing but then i dont get the air flow and ease of access i want from hanging stuff.


Your way works if your in a tent or somethinv with walls. , im not saying its perfect .

But its pretty easy working in there for me . And for how much light is lost i really dont care ,, il sacrifice it to be able to walk around my entire grow and to reach in and see any time without ripping reflective shit on and off lol.

Less problems when i have more airflow as well.
it produces great and its easy to work around.

Theres a balance between efficiency and ergonomics and pests.

K. I. S. S.
 
wietefras

wietefras

Well-Known Member
Airwalker16 said:
Bruh, don't take offense. He's clearly not coming at you or anything. Just stating what he's doing. Your information is very useful and I'm sure it will enlighten more people to come that may read this.
Click to expand...
Well I simply pointed out that this non even spacing trick doesn't "work" because he was pointing out that that was such a great idea.

Perhaps I shouldn't waste my time on something so trivial (the difference is really insignificant to the plants), but I'm not sure why all this goal post moving is needed either.

Lets add some light uniformity maps.

Seven 56cm strips @7cm height over 100cm x 70cm evenly spaced (with rather poorly reflective walls):
Distribution_Strip_Even.png

same number of strips spaced unevenly, biased towards the walls (based on a fixture I saw here somewhere):
Distribution_Strip_Uneven.png

There is clearly no "hot spot" with the even spaced setup. Although there obviously always will be an area where the light is ever so slightly brighter. With uneven spaced strips this area has simply moved more towards the walls where the strips are spaced closer. The effect is actually more pronounced with the uneven spaced strips "hot spots" producing a higher relative difference to the surrounding intensity.

So with uneven spacing you get: less uniformity, overall slightly less light and slightly brighter "hot spots" (albeit slightly off center).
 
projectinfo

projectinfo

Well-Known Member
And ive ran these at two inches befor lol and burned the center . Ive learned since then and this setup works great
DSC_1330.JPG

DSC_1332.JPG

Had a few hiccups last time, this round should be good , stay tuned, engineer ;)
 
projectinfo

projectinfo

Well-Known Member
wietefras said:
It's been a while since I did this. I didn't do 12", but at 18" there was no difference anymore at all. It's just one big blur. With less than half the total amount of light from the optimal height of 7cm still left though.

The higher the light hangs, the less any of this matters.
Click to expand...
I think your splittng
KonopCh said:
@projectinfo which strips do you have and how hard you drive them? Is this heatsink just ALU bar or U channel? What's temp?
Click to expand...
This time i used bridgelux gen 2
I had a 4x8 sheet of aluminum at 1/4 inch or thinner maybe.

I cut it a bit bigger than the strips on the table saw and theres my heat sinks.

Goto a welding shop or boatshop or fabrication place and theyll probably make you noce ones with scrap metal for fuck all $$

My lights are attached with double sided thermal transfer tape and secured with self tapping screws.

My lights all run cool - luke warm even in flower.

My drivers are 240w meanwells a seriers i put a dimmer on myself


I run then at about 10k lux for clones
25--40 for veg
50-60 for flower.

I raise, lower and dim according to the readings i get. Thanks @Randomblame for the general lux reading .

Its Been working great

http://ledgardener.com/diy-led-strip-build-designs-samsung-bridgelux/

Here you go ;)
 
D

Dave455

Well-Known Member
wietefras said:
Well I simply pointed out that this non even spacing trick doesn't "work" because he was pointing out that that was such a great idea.

Perhaps I shouldn't waste my time on something so trivial (the difference is really insignificant to the plants), but I'm not sure why all this goal post moving is needed either.

Lets add some light uniformity maps.

Seven 56cm strips @7cm height over 100cm x 70cm evenly spaced (with rather poorly reflective walls):
View attachment 4202260

same number of strips spaced unevenly, biased towards the walls (based on a fixture I saw here somewhere):
View attachment 4202261

There is clearly no "hot spot" with the even spaced setup. Although there obviously always will be an area where the light is ever so slightly brighter. With uneven spaced strips this area has simply moved more towards the walls where the strips are spaced closer. The effect is actually more pronounced with the uneven spaced strips "hot spots" producing a higher relative difference to the surrounding intensity.

So with uneven spacing you get: less uniformity, overall slightly less light and slightly brighter "hot spots" (albeit slightly off center).
Click to expand...
Have any on evenly spaced COBS
 
You must log in or register to reply here.
Top