To LED or not LED

[CuriousHeart]

Looking for lighting for a 4 x 4 grow. I am worried about the light footprint. The LED lights are either a square box or a long rectangle and I am not for sure if all the "Ladies" will get equal light. I was throwing around the idea of getting two smaller lights and essentially cut my grow table in half. Does anyone think that would optimize the light footprint? AND any opinions on Apollo LEDs or Lush LEDS


Thanks

"When you smoke the herb, it reveals you to yourself."―Bob Marley

 

[Scientific]

When you look at the light footprint of lights, you can see that it's kind of a bulls eye, with highest light at the center. Given that, yeah, I would think that two lights could more even coverage than one. But I doubt that's worth the added cost and complexity.

 

[zSaber]

Yeah it's best to get 2 separate lights then your light coverage will be more even.

 

[Scientific]

Seeing how uneven the distribution is, i have thought about hanging some kind of diffuser under the center of the light to even up the distribution, but that's probably too complicated...

 

[ShiggityFlip]

I came across the same questions awhile back. I decided the ideal use of LEDs is to play to their strengths. The ability to have complete even coverage and to have lights that sit 12" above the canopy without burning. These high efficiency whites run at over 60% efficiency. Blurples like kind or lush run at little over 40%.

 

[Driller2500]

The difference in led and HPS in picture form
Same set did an experiment
They are four weeks in flower

 

[Scientific]

The difference in led and HPS in picture form

That's dramatic and interesting. Do you know that the lights were producing the same amount of light? Or from a less purely scientific and more practical perspective (my electric bill...), were they using the same amount of electric current (i.e. consuming the same amount of power)? And to go back to being all scientific and skeptical again, I would want that to be measured power consumption, not what's not the label on the box (as in "300 watt" LED units that run at a fraction of that). Comparing apples with apples and all that...

 

[Driller2500]

That's dramatic and interesting. Do you know that the lights were producing the same amount of light? Or from a less purely scientific and more practical perspective (my electric bill...), were they using the same amount of electric current (i.e. consuming the same amount of power)? And to go back to being all scientific and skeptical again, I would want that to be measured power consumption, not what's not the label on the box (as in "300 watt" LED units that run at a fraction of that). Comparing apples with apples and all that...

So I didn't go that far but because there damn close the HPS is running at 750 watts and the two leds are 600 watt each so they pretty close but I was looking for a purely production stand point not the consumption of power but my bill went up
30 dollars when I added the HPS

 

[Scientific]

Ah, very interesting. Thanks Driller. Like a lot of people, I'm trying to decide which way to go, newfangled bizarro purple LED light or or old and established bizarro yellow HPS light.

 

[ShiggityFlip]

So I didn't go that far but because there damn close the HPS is running at 750 watts and the two leds are 600 watt each so they pretty close but I was looking for a purely production stand point not the consumption of power but my bill went up
30 dollars when I added the HPS

And really you have to say that would be applicable only to last generations LEDs. This generation is much more efficient. CREE did a study and replaced the PAR output of an HPS SE with 650w of Cree LEDs and not even the most efficient ones.

 

[ShiggityFlip]

Then you must also consider the cooling costs of each light. I am hitting about 60% efficiency with my light. That means 40% of the power used is converted to heat. An hps of the same wattage is about 35%efficient. That means 65% of its wattage is converted to heat. So when including wattage you must also account for heat that needs to be cooled.

 

[Scientific]

Intersting. After over 40 years of development, LED technology continues to improve dramatically.

 

[ShiggityFlip]

Yeah it's crazy. I got into LEDs for the current blurples. They put out some amazing quality but still couldn't beat HPS in the quality department because their efficiency is in the 40ish% range.

Things have come far since then. Now white leds are hitting efficiencies of 55-65%. We are also finding that even green light can be utilized well by the plant for photosynthesis so it is much more useful than we imagined.

So the 15% + efficiency over blurples or HPS also means much less heat while giving more light. It's a new day in indoor growing and the future is bright!!

 

[Driller2500]

So this week I ran into the dreaded heat of HPS light my flower room has been running at like 82 but this last week like 84-86 degrees so I broke down and ordered the perfect sun 1000 watt LED to replace the HPS I am running at 750 watts but it's gonna be nice won't have to worry about temp and saving a little electric !! So when I do put the LED in I will be running 2200 watts of light .
It's just to early into summer it's gonna get way to hot and I don't wanna risk it !!! In the last 51 days of flower wish me luck !!