How many watts and lumens is a good target for a 4x4

[tilopa]

Still trying to figure out best driver and configuration, but I should have started my design with the question in the title in mind.

I was going to go with 460w and about 74,400 lumens (according to my led strips data sheet), but the wiring configuration is complicated and will lead to losses in wiring.
So, I found a better solutions with a different driver and same strips but that lowers power and lumens to 400w and 65,850.

I was going by the spider-farmer sf-4000 as a target, which is 79095 lm @ 438w.

So, what is a good wattage and lumen number for a 4x4 fixture?

 

[Airwalker16]

Watts are 480-600. Lumens are totally depending on how you get up to that wattage. 4 boards?l, Or 60 strips all running less than half an amp? This is where efficiency makes a huge play since lower current to bring up lumens per watt.

 

[GBAUTO]

A 4x4 is approx. 1.5 m2.
To achieve an average of 750ppfd, you'll need (750x1.5)=1125 umole ppf.
That's how to calculate how 'much' light you'll need to hit an average for the room.
The efficiency of the fixture will determine how many watts it'll need to get to that number.

 

[Bignutes]

With efficient strips I shoot for 30 w/sq ft to make it simple.

 

[tilopa]

A 4x4 is approx. 1.5 m2.
To achieve an average of 750ppfd, you'll need (750x1.5)=1125 umole ppf.
That's how to calculate how 'much' light you'll need to hit an average for the room.
The efficiency of the fixture will determine how many watts it'll need to get to that number.

Is it possible to figure out the ppf from the data in the datasheet? which is basically just volts, current, watts, and lumens.

 

[end_of_the_tunnel]

Is it possible to figure out the ppf from the data in the datasheet? which is basically just volts, current, watts, and lumens.

You could try using these calculators for a rough idea. They have conversion rates for 3000K and 4000K samsung leds. https://horticulturelightinggroup.com/blogs/calculators/converting-lux-to-ppfd
If you are looking at samsung strips you can try this basic calculator.

Engine Calculator | SAMSUNG LED | Samsung LED Global Website

Engine Calculator - Support. Calculate engine at Samsung LED global website quickly and easily

www.samsung.com

Take care confusing PPF and PPFD metrics when comparing different lights.
One light made with a compact board layout needs to be hung high and because of that needs to be driven at a higher wattage.
Another light using identical diode and quantity, in a spreadout strip format, could be hung much closer to canopy. And as a result can be driven at lower current.

Board type lights = manufacturers commonly recommend 30w/ sq ft or more.
Strip builds = examples on rollitup 25w/ sq ft or less.
Check cobshopgrows bridgelux thread. Full of current info.
Check Jarvilds posts. Samsung strips and samsung plus supplement uv/red/far red.

Spend a lot of time researching a build, or just get a premade product that has extended online forum reports highlighting longevity and reliability and company afterservice. (not silly box-opening highlight overviews on youtube masquerading as reviews.)

Buy a premade light is quick and easy. Build needs research, use search function and be surprised at how many of your questions. have been answered.

 

[tilopa]

Thanks. I have been researching my ass off, but realizing that I still need to do more. Before I replace 2 Gavita DE 1000 HPS, and spend twice the money, I want to make sure I get lights that don't lower my yield, or worse, quality.

One big plus that I keep coming back to with these strip type builds I'm wanting to do is you can build it so that the light covers your entire canopy. With many of the big name turnkey products like Black Dog Their lights are relatively tiny. Black Dog's 1000w led, which they say can cover 6.5' x 6.5' area is only 21" x 21". And if you look at their PAR diag. all the outer edges have much reduced light. Which also means if you lower the light even more those outer edges get even less light.

With strips with many smaller diodes you can arrange them so the light covers the canopy, and lower them much closer to the plant without loosing that coverage.

Is there any negative aspects to having the diodes that close to the plants?

 

[DukeFluke]

Edit: thought I was replying to a different thread

 

[Airwalker16]

Thanks. I have been researching my ass off, but realizing that I still need to do more. Before I replace 2 Gavita DE 1000 HPS, and spend twice the money, I want to make sure I get lights that don't lower my yield, or worse, quality.

One big plus that I keep coming back to with these strip type builds I'm wanting to do is you can build it so that the light covers your entire canopy. With many of the big name turnkey products like Black Dog Their lights are relatively tiny. Black Dog's 1000w led, which they say can cover 6.5' x 6.5' area is only 21" x 21". And if you look at their PAR diag. all the outer edges have much reduced light. Which also means if you lower the light even more those outer edges get even less light.

With strips with many smaller diodes you can arrange them so the light covers the canopy, and lower them much closer to the plant without loosing that coverage.

Is there any negative aspects to having the diodes that close to the plants?

Ding ding ding. He's figured out the beauty of strips!

 

[jimihendrix1]

HLG 650R is made for a 4 x 4-5 x 5 and is 1770 PPF x 630w.

 

[TreeFarmerCharlie]

HLG 650R is made for a 4 x 4 and is 1700 umol x 630w.

They designed the 650R for a 5x5. The HLG 550 is what they recommend for a 4x4.

 

[jimihendrix1]

Yeah but its only 100 more umole than a 1000w Hortilux HPS at 1600PPF. HLG is 1700-1770. Ive seen both measurements. But is still rated at only 70 more PPF than the Gavita 1700e at best.

DE Gavita is 2100 PPF, rated 5 x 5 and is 400 more PPF. IMHO HLG is stretching measurements just a little, though they will work in the advertised 5 x 5.

Gavita rates the 1700e at 4 x 4, and HLG 5 x 5. Both are basically the same power. Ill believe Gavita.

Gavita says their 1700e, which I own is made for a 4 x 4 and a direct replacement for a 1000w HID.

Phillips also makes the Toplight Compact, and is 1800PPF, and 630w, and they rate it at a 4 x 4. They wont sell these individually though. $32,000 for 40 of them.

 

[CaliWorthington]

This is the calculator you want.

HLG PPF to PPFD Calculator

It's simple. Take the luminous efficacy number from your strip's data sheet, multiply it by the number of strips, and plug it into the calculator with the length x width of your grow.

Take for example, a Samsung F strip L09 3000k. It's average (not max) luminous efficacy is 168 lumens per watt at 1.1 amps. 168 x 8 strips= 1344 total PPF. For a 4'x4' grow where 85% of the light reaches it's target, that comes out to 768.54 PPFD per square meter.

You want to use a luminous efficacy number that corresponds to the current you'll be running the strips at.

750 PPFD is a good average. Anything between 600 and 800 should be fine for flowering. If you want something that will produce like your HPS, don't run the strips too soft, unless you have a lot of them. The 8 strip build above would run at 1.25 amps per strip wired in parallel on a Mean Well HLG-480H-48B (or 48A) or a pair of 240's. The numbers above were running at 1.1 amps, so this would have a higher PPFD (at 1.25 amps). And it would be 30 watts per square foot.

Sorry I edited that about 10 times.

 

[Airwalker16]

Yeah but its only 100 more umole than a 1000w Hortilux HPS at 1600PPF. HLG is 1700-1770. Ive seen both measurements. But is still rated at only 70 more PPF than the Gavita 1700e at best.

DE Gavita is 2100 PPF, rated 5 x 5 and is 400 more PPF. IMHO HLG is stretching measurements just a little, though they will work in the advertised 5 x 5.

Gavita rates the 1700e at 4 x 4, and HLG 5 x 5. Both are basically the same power. Ill believe Gavita.

Gavita says their 1700e, which I own is made for a 4 x 4 and a direct replacement for a 1000w HID.

Phillips also makes the Toplight Compact, and is 1800PPF, and 630w, and they rate it at a 4 x 4. They wont sell these individually though. $32,000 for 40 of them.

The bar build of gravitas led confines it to a 4x4. HLGs light utilizes the 120° beam angle of LEDs and gives it that extra 6" of spread along the edges.

 

[tilopa]

This is the calculator you want.

HLG PPF to PPFD Calculator

It's simple. Take the luminous efficacy number from your strip's data sheet, multiply it by the number of strips, and plug it into the calculator with the length x width of your grow.

Take for example, a Samsung F strip L09 3000k. It's average (not max) luminous efficacy is 168 lumens per watt at 1.1 amps. 168 x 8 strips= 1344 total PPF. For a 4'x4' grow where 85% of the light reaches it's target, that comes out to 768.54 PPFD per square meter.

You want to use a luminous efficacy number that corresponds to the current you'll be running the strips at.

750 PPFD is a good average. Anything between 600 and 800 should be fine for flowering. If you want something that will produce like your HPS, don't run the strips too soft, unless you have a lot of them. The 8 strip build above would run at 1.25 amps per strip wired in parallel on a Mean Well HLG-480H-48B (or 48A) or a pair of 240's. The numbers above were running at 1.1 amps, so this would have a higher PPFD (at 1.25 amps). And it would be 30 watts per square foot.

Thanks Cali.

So, my strips optimal effiency (@ 700mA) = 164 lm/w. But I'll need to run mine at 933mA= 159 lm/w in order to hit the wattage of 540w people are telling me I need.

So, 159 x 30 (strips) = 4770. I plug that into the calculator and get = 2727. That doesn't make sense. The data that is missing is the actual power (watts) being applied, or the actual total lumens. I could run 30 strips at an ultra low current and my efficiency would be higher (and therefore the PPFD according to this calculator) yet my total lumens (and power) would be much lower.

This calculator is better:

Converting Lux to PPFD & Measuring Lux with Smartphone

Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...

horticulturelightinggroup.com

I can find my lux with this calculator:

Watts to lux (lx) conversion calculator

Electric power in watts (W) to illuminance in lux (lx) calculator and how to calculate.

www.rapidtables.com

which is: 57761 plug that into the other calc and get: 894.78 PPFD

 

[CaliWorthington]

Thanks Cali.

So, my strips optimal effiency (@ 700mA) = 164 lm/w. But I'll need to run mine at 933mA= 159 lm/w in order to hit the wattage of 540w people are telling me I need.

So, 159 x 30 (strips) = 4770. I plug that into the calculator and get = 2727. That doesn't make sense. The data that is missing is the actual power (watts) being applied, or the actual total lumens. I could run 30 strips at an ultra low current and my efficiency would be higher (and therefore the PPFD according to this calculator) yet my total lumens (and power) would be much lower.

This calculator is better:

Converting Lux to PPFD & Measuring Lux with Smartphone

Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...

horticulturelightinggroup.com

I can find my lux with this calculator:

Watts to lux (lx) conversion calculator

Electric power in watts (W) to illuminance in lux (lx) calculator and how to calculate.

www.rapidtables.com

which is: 57761 plug that into the other calc and get: 894.78 PPFD

You need to hit a target PPFD, not a target watts. Watts are how you get there, they're not the target.

Maybe I'm reading this wrong, but you're talking about 30 strips in a 4x4? That's massive overkill. Running at 700mA, 164lm/w, 30 strips in a 4x4 given 25% light loss is 2482 PPFD. That's 3 times more than you need.

10 strips running at 700mA in a 4x4 with 25% light loss gives me 827 PPFD using the calculator I linked to.

 

[jimihendrix1]

The bar build of gravitas led confines it to a 4x4. HLGs light utilizes the 120° beam angle of LEDs and gives it that extra 6" of spread along the edges.

The Gavita is WAY BIGGER Dimensionally vs the HLG. Hard to see how the HLG would cover the area better when the Gavita is almost 4ft x 4ft. Gavita is HUGE.

44 in x 44 in x 2.5 in. For the Gavita

VS
for HLG.

29 x 22 x 4 inches

Gavita is 15 inches longer and DOUBLE WIDTH at 44 inches. Gavita is also 1.5 inches slimmer.

 

[tilopa]

You need to hit a target PPFD, not a target watts. Watts are how you get there, they're not the target.

Maybe I'm reading this wrong, but you're talking about 30 strips in a 4x4? That's massive overkill. Running at 700mA, 164lm/w, 30 strips in a 4x4 given 25% light loss is 2482 PPFD. That's 4 times more than you need.

10 strips running at 700mA in a 4x4 with 25% light loss gives me 827 PPFD using the calculator I linked to.

That is not correct my friend. You cannot get PPF (which is total photon energy output, or simply light) by only considering efficiency and number of strips. Like I pointed out you could make your strips more efficient by running them at a lower current, which lowers there power output and lumens, yet according to that calculator would increase the PPFD. Not possible.

 

[CaliWorthington]

That is not correct my friend. You cannot get PPF (which is total photon energy output, or simply light) by only considering efficiency and number of strips. Like I pointed out you could make your strips more efficient by running them at a lower current, which lowers there power output and lumens, yet according to that calculator would increase the PPFD. Not possible.

Unless you have the exact luminous efficacy numbers at the current you're running, you're guessing.

 

[tilopa]

Unless you have the exact luminous efficacy numbers at the current you're running, you're guessing.

The exact luminous efficacy is easy to calculate, it is given in the datasheet. One strip is 2195 lumens at 700mA and 19.1v. If I run it at 933mA and 19.4v (18.1w), the chart in the datasheet: https://www.bridgelux.com/sites/default/files/resource_media/DS132 Bridgelux EB Series Gen3 Data Sheet 20190617 Rev A.pdf
shows that at 933mA the lumen output is: 131% of nominal (2195) = 2195 x 1.31 = 2875. The luminous efficiency is 2875 lm / 18.1w = 158 lm/w.