All LED Indoor Grow- Quantum Boards vs AutoCob's

lukio

lukio

Well-Known Member
Bosgrower said:
Glad you're not adamant about that 'cause the wattage drawn by a fixture doesn't dictate how much goes to heat and how much goes to photons. If memory serves, LED efficiency driven at favorable amperage results in 50%or higher photon:heat ratios while HPS will be significantly lower photon:heat ratio around 35%.
I run an 800w 16 COB fixture with passive cooling in a 5x5 and maintain a 75-80F temperature range. The drivers (Equivalent to the hips ballasts) are mounted outside the tent but even if I moved them into the tent, there would still be a large temperature differential favoring the LEDs
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coooool, i get the efficiency thing - photon/heat output...these leds ARE putting out way more photons than heat compared to hps but its still just as hot in my tent? why is that? same watts and the same extraction. doesnt make much sense. According to robin the drivers only amount to 10% of the heat.

i had six 260w QB kits and a 400w panel full of osrams in a 4x8, which is totally overkill i know - i had to remove two 260w kits and dim the others to 200w to get the temps down to match a 600hps, 2 kits and the orsam panel i had set up before...it caught me out...i guess the jump in watts was higher than the difference in efficiency?
 
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MrTwist1

MrTwist1

Well-Known Member
lukio said:
coooool, i get the efficiency thing - photon/heat output...these leds ARE putting out way more photons than heat compared to hps but its still just as hot in my tent? why is that? same watts and the same extraction. doesnt make much sense. According to robin the drivers only amount to 10% of the heat.

i had six 260w QB kits and a 400w panel full of osrams in a 4x8, which is totally overkill i know - i had to remove two 260w kits and dim the others to 200w to get the temps down to match a 600hps, 2 kits and the orsam panel i had set up before...it caught me out...i guess the jump in watts was higher than the difference in efficiency?
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Yeah that must be the problem, because @Bosgrower is right... quality LED efficiency is much more efficient which more more photons and less heat. With that said, there is just a point whereby your extraction just can't keep up...unless the air being drawn in is much cooler.
 
GroErr

GroErr

Well-Known Member
MrTwist1 said:
Yeah that must be the problem, because With that said, there is just a point whereby your extraction just can't keep up...unless the air being drawn in is much cooler.
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That's the key right there, every room has it's limit for extracting heat. When you reach that (amount of heat/watts) limit your only real option is to reduce the heat being generated (dim if dimmable) or bring in cooler air. I see that in my room running COBs and I monitor with digital/WiFi sensors so I can see the temps/RH every 15 minutes to gage the effects of different cooling strategies. if I have 800w running full on I need cooler air coming in and crank the inline bringing cooler air in to bring the temps down. It works in conjunction with your exhaust. If you crank your incoming air, your exhaust should be slightly less if you're using a variable controller on your inline's, otherwise you're extracting air too fast for the cooler air to bring temps down.
 
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Roger A. Shrubber

Roger A. Shrubber

Well-Known Member
photons degrade into heat, they heat up the walls of the tent when they strike it, they heat up your plants when they hit them.....i HATE this law....i know it intellectually, but it just seems WRONG to me...but no matter the efficiency, if you put 1000 watts into a light, it's going to produce 1000 watts worth of heat. whether its an h.i.d. light, or the best top bin cob. period. end of the story.
the savings (in heat and money) come from getting more photons per watt, so you can use less watts to get the same result. thats it. period. took me forever to accept that...not sure i do deep in my heart, even now.....but thats the way it works.
 
GroErr

GroErr

Well-Known Member
Roger A. Shrubber said:
photons degrade into heat, they heat up the walls of the tent when they strike it, they heat up your plants when they hit them.....i HATE this law....i know it intellectually, but it just seems WRONG to me...but no matter the efficiency, if you put 1000 watts into a light, it's going to produce 1000 watts worth of heat. whether its an h.i.d. light, or the best top bin cob. period. end of the story.
the savings (in heat and money) come from getting more photons per watt, so you can use less watts to get the same result. thats it. period. took me forever to accept that...not sure i do deep in my heart, even now.....but thats the way it works.
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I know what you mean, still struggling to reconcile this. I'm running 800w of 3590's @1400ma and stuck to 1400ma drivers because I believe driving them softer generates less heat. Which is probably where the difference lies. Whether using an LED driver or ballast, both generate heat, why some folks run remote drivers/ballasts. All I know right now is I can run 800w @1400ma cooler than 630w of CMH (730w with thew ballasts) with both drivers/ballasts in the room (internal ballasts on the CMH, internal drivers on the COBs). Which is why I'm still struggling to reconcile the watt is a watt theory.
 
Bosgrower

Bosgrower

Well-Known Member
The key issue is how hard you drive your LEDs. If you use more LEDs at lower amperage to achieve your PPFD goals, you will be maintaining a higher photon:heat ratio. Look at any LED mfr spec sheet (the IC makers not the fixture makers) and you'll see how their devices are going to work at various amperage and voltage levels. There is also the matter of the driver's efficiency.
So with regard to the comment that 1000w will always generate 1000w worth of heat, I must respectfully disagree.
The watt (symbol: W) is a derived unit of power in the International System of Units (SI) defined as 1 joule per second and can be used to quantify the rate of energy transfer.
It does not, however, have anything to do with how efficiently those joules are used.
As an example, look at an incandescent bulb vs an LED bulb.
A 100w incandescent bulb is designed to generate photons inefficiently by passing electricity through a highly resistant wire filament making it glow white hot. That's why you see the (somewhat disingenuous) wattage equivalents on LED packaging showing that a 15w bulb will produce the same photon density as the 100w traditional bulb
 
Bosgrower

Bosgrower

Well-Known Member
GroErr said:
I know what you mean, still struggling to reconcile this. I'm running 800w of 3590's @1400ma and stuck to 1400ma drivers because I believe driving them softer generates less heat. Which is probably where the difference lies. Whether using an LED driver or ballast, both generate heat, why some folks run remote drivers/ballasts. All I know right now is I can run 800w @1400ma cooler than 630w of CMH (730w with thew ballasts) with both drivers/ballasts in the room (internal ballasts on the CMH, internal drivers on the COBs). Which is why I'm still struggling to reconcile the watt is a watt theory.
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No need to struggle. A watt is indeed a watt, but how you use them makes all the difference
 
GroErr

GroErr

Well-Known Member
Bosgrower said:
No need to struggle. A watt is indeed a watt, but how you use them makes all the difference
Click to expand...
Lol, yeah true enough, whatever tech you're using the total environment/methods make the difference between blah and wow grows. That's part of the reason I'd like to know the answer using different techs. A few degrees, running the same wattage but different tech can make the difference between blah and wow.

LED is not as clear as with hid/hps/cmh type ballasts. With LED drivers you can choose how hard you drive them and variable drivers (ability to choose the amperage) aren't available so you have to make a decision up-front. If driving them at 1400ma vs. 2800ma, running the same total wattage, if there's even a 2-3F difference (more heat being generated by the drivers at higher amps) it could mean a world of difference in a smaller room or cabinet.
 
Roger A. Shrubber

Roger A. Shrubber

Well-Known Member
i'm actually not that familiar with drivers, as i understand it, they use constant voltage and you adjust the wattage, which changes the amperage on its own. my rig is just the opposite, my wattage is constant and i adjust both the voltage and the amperage with a buck converter, so...when you say 1400 ma, that's what you're driving each string of them at ? or the whole board is splitting 1.4 amps? cause each of those answers is radically different.
i'm splitting 4.5 amps between 336 diodes. 13.39 ma each diode. 160.68 per string. 1124.76 per panel, X 4 =4499 for the whole 4 panel board. all of this is at 43 volts. i have heatsinks and pc fans on each panel. the leds are rated to 175 and i've never seen one go over 130, and thats the actual led with my laser thermometer, not the board or the sink. the tent stays in the mid 70s with one small fan blowing up through the plant towards the surface of the light, and a 4 inch booster fan hooked to a small phresh filter, more for odor than heat.
i'm still learning the math that goes with all of this, i know higher voltage means you have lower amperage...so your driver must run higher voltage than my rig?....
 
GroErr

GroErr

Well-Known Member
Roger A. Shrubber said:
i'm actually not that familiar with drivers, as i understand it, they use constant voltage and you adjust the wattage, which changes the amperage on its own. my rig is just the opposite, my wattage is constant and i adjust both the voltage and the amperage with a buck converter, so...when you say 1400 ma, that's what you're driving each string of them at ? or the whole board is splitting 1.4 amps? cause each of those answers is radically different.
i'm splitting 4.5 amps between 336 diodes. 13.39 ma each diode. 160.68 per string. 1124.76 per panel, X 4 =4499 for the whole 4 panel board. all of this is at 43 volts. i have heatsinks and pc fans on each panel. the leds are rated to 175 and i've never seen one go over 130, and thats the actual led with my laser thermometer, not the board or the sink. the tent stays in the mid 70s with one small fan blowing up through the plant towards the surface of the light, and a 4 inch booster fan hooked to a small phresh filter, more for odor than heat.
i'm still learning the math that goes with all of this, i know higher voltage means you have lower amperage...so your driver must run higher voltage than my rig?....
Click to expand...
Yeah they vary in voltage which relates to the amperage output. You can have a single driver or multiple smaller/individual drivers but you have to select that option up-front or replace the drivers. Not up on the math or how each option correlates to heat, should do some googling on that ;)
 
Roger A. Shrubber

Roger A. Shrubber

Well-Known Member
Bosgrower said:
The key issue is how hard you drive your LEDs. If you use more LEDs at lower amperage to achieve your PPFD goals, you will be maintaining a higher photon:heat ratio. Look at any LED mfr spec sheet (the IC makers not the fixture makers) and you'll see how their devices are going to work at various amperage and voltage levels. There is also the matter of the driver's efficiency.
So with regard to the comment that 1000w will always generate 1000w worth of heat, I must respectfully disagree.
The watt (symbol: W) is a derived unit of power in the International System of Units (SI) defined as 1 joule per second and can be used to quantify the rate of energy transfer.
It does not, however, have anything to do with how efficiently those joules are used.
As an example, look at an incandescent bulb vs an LED bulb.
A 100w incandescent bulb is designed to generate photons inefficiently by passing electricity through a highly resistant wire filament making it glow white hot. That's why you see the (somewhat disingenuous) wattage equivalents on LED packaging showing that a 15w bulb will produce the same photon density as the 100w traditional bulb
Click to expand...
disagree all you want, ask @robincnn or @Stephenj37826 , two gentlemen who do this for a living. if it goes in, it comes out
 
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Evil-Mobo

Evil-Mobo

Well-Known Member
Ok guys, question as I need to do something with these girls or I fear I will run out of vertical space.

I know SCROG is a subject of much debate and I have never done one, but I am considering it for this grow. If not then just a trellis layer or two for support but........

Any input is appreciated
 
ttystikk

ttystikk

Well-Known Member
Evil-Mobo said:
Ok guys, question as I need to do something with these girls or I fear I will run out of vertical space.

I know SCROG is a subject of much debate and I have never done one, but I am considering it for this grow. If not then just a trellis layer or two for support but........

Any input is appreciated
Click to expand...
The idea is top to the plant and spread it out across the screen so it fills the space. It's a way to manage the canopy so it's more level and maintains the proper distance from the light source.
 
F

Fevs

Well-Known Member
See I don't know for sure, but this is how I always understood it.

Say you have a 1000w hid, with a completely shite spectrum

vs

a 1000w hid, with a decent more efficient spectrum, more par, umols...

Both ballasts will run the same wattage and give off the same heat.

However inside the tents, the lamp with less useable light will create more heat, as the light isn't being absorbed by the plant as much, therefore remains as heat.

Like I said, I don't know for sure.

Either way I grow with cob thesedays. I have 1600w of cobs, split over two 4ft x 4ft tents, two 3ft x 3ft tent and a small wardrobe. I grow like that so I can spread the heat round my apartment. Those tents are split over 3 rooms.

I cannot run 1000w hid in a single room this time of year. It's just too hot and I can't get rid of the heat. Spreading my tents round I can grow more weed, with less 'overall' heat in my apartment.
 
Moflow

Moflow

Well-Known Member
Fevs said:
See I don't know for sure, but this is how I always understood it.

Say you have a 1000w hid, with a completely shite spectrum

vs

a 1000w hid, with a decent more efficient spectrum, more par, umols...

Both ballasts will run the same wattage and give off the same heat.

However inside the tents, the lamp with less useable light will create more heat, as the light isn't being absorbed by the plant as much, therefore remains as heat.

Like I said, I don't know for sure.

Either way I grow with cob thesedays. I have 1600w of cobs, split over two 4ft x 4ft tents, two 3ft x 3ft tent and a small wardrobe. I grow like that so I can spread the heat round my apartment. Those tents are split over 3 rooms.

I cannot run 1000w hid in a single room this time of year. It's just too hot and I can't get rid of the heat. Spreading my tents round I can grow more weed, with less 'overall' heat in my apartment.
Click to expand...
Less hotspots lol
 
Evil-Mobo

Evil-Mobo

Well-Known Member
ttystikk said:
The idea is top to the plant and spread it out across the screen so it fills the space. It's a way to manage the canopy so it's more level and maintains the proper distance from the light source.
Click to expand...
Oh I know about topping and they have been topped various times as is but just going off of the starting height for flowering and looking at minimum distance needed between light and canopy and available height and it's not adding up to me lol
 
Moflow

Moflow

Well-Known Member
Evil-Mobo said:
Oh I know about topping and they have been topped various times as is but just going off of the starting height for flowering and looking at minimum distance needed between light and canopy and available height and it's not adding up to me lol
Click to expand...
If the branches are the supple type you could tie them down or wire them down.
Could give you an extra foot or so.
:cool:
 
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