Lowest heat production for a small tent

gwheels

gwheels

Well-Known Member
Lets say you have a 2 x 4 or a 2 x 3 x 6 foot tall tent

What do you think is the lowest heat option for that tent? Using a scrubber and such helps but heat is a big issue in a small space.

I have a 315 CMH i use in a 4 x 4 and it is manageable

I have a 200 watt vero i use in a 20 x 36 x 62 and it is now manageable but i had to dick around with my exhaust to make it work.

Would a 240 watt quantum board produce more heat than the 200 watt vero?

And 1 watt of light does not produce 1 watt of heat. Some of the light is used as energy for the plants. The more inefficient a light is the more heat it will produce. But it is not a linear equation.

How is the heat on your samsung quantum boards? I am really thinking about a 2 panel kit from timber and making a frame work to hold them sideways (so it is 24 x 7 inches for the frame roughly).
 
ANC

ANC

Well-Known Member
By a rough and unscientific approach, the Samsung double 4 foot strips Heat up at about 0.4 C/W above ambient.
 
GBAUTO

GBAUTO

Well-Known Member
gwheels said:
And 1 watt of light does not produce 1 watt of heat. Some of the light is used as energy for the plants. The more inefficient a light is the more heat it will produce. But it is not a linear equation.
Click to expand...
I agree with this statement but I think that the difference in efficacy of the different light sources(boards. strips, etc.) won't make much of a difference in thermal load. I'd focus on removing heat through ventilation.
 
gwheels

gwheels

Well-Known Member
I think I can not beat my timber 200 watt vero. Now that the heat is being extracted it is very workable. And Dan I love that light. LOVE IT. But I am wondering if there is a better heat light. Not to dissipate it because that make sense but a lesser producer of heat would be pretty rocking.
 
nc208

nc208

Well-Known Member
gwheels said:
I think I can not beat my timber 200 watt vero. Now that the heat is being extracted it is very workable. And Dan I love that light. LOVE IT. But I am wondering if there is a better heat light. Not to dissipate it because that make sense but a lesser producer of heat would be pretty rocking.
Click to expand...
Skies the limit in terms of how you want to cool. Active cooling is very effective but if you want to go even further you could look at water cooled rigs. Some people on here have built some cool setups that will keep your cobs running cool.

What temps are your cobs running at?
 
gwheels

gwheels

Well-Known Member
I want only active cooling. I have achieved it but what would you do with no vents ? just intake and exhaust. How small can you go in wattage. I think quantum boards are the way to go. 240 watts over 600 etc.

That being said I love my timber framework 2 X 100 veros

I love my 315 CMH in my larger tent.
 
gwheels

gwheels

Well-Known Member
Since i put my scrub vent in my furnace intake my temps dropped a lot. I am down to less than 80 degrees full light after 12 hours with fan on a veriac at 25%. BUT I would love to advise people of a better way.
I am a bad example I want to grow pound a run so I can live on cookies for 3 months. But that is me.
What is available at 240 watts for the lowest heat.

PS the heat of cobs surprised me. My 315 is about the same.
 
1

1212ham

Well-Known Member
gwheels said:
And 1 watt of light does not produce 1 watt of heat. Some of the light is used as energy for the plants. The more inefficient a light is the more heat it will produce. But it is not a linear equation.
Click to expand...
How much heat does 1 watt produce?
 
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GrowLightResearch

GrowLightResearch

Well-Known Member
1212ham said:
How much heat does 1 watt produce?
Click to expand...
A 2 watt OSRAM Olson SSL Hyper Red produces about 30% heat and 70% radiant energy (photons) @ 500mA or 1 watt.
When the these photons strike a leaf, the leaf will absorb close to 100% of the photon's energy. The absorbing chlorophyll will transfer nearly 100% of the photon's energy to the carbon reaction center. Therefore the photochemical quantum yield is 100%.
 
1

1212ham

Well-Known Member
gwheels said:
Would a 240 watt quantum board produce more heat than the 200 watt vero?

And 1 watt of light does not produce 1 watt of heat. Some of the light is used as energy for the plants. The more inefficient a light is the more heat it will produce. But it is not a linear equation.

How is the heat on your samsung quantum boards? I am really thinking about a 2 panel kit from timber and making a frame work to hold them sideways (so it is 24 x 7 inches for the frame roughly).
Click to expand...
The QB will produce more heat than the Vero since it draws more power. I think there could be a reduction in heat with strips compared to the Vero due to their high efficiency and efficacy, but I also think it would be a very small difference.
 
gwheels

gwheels

Well-Known Member
1 watt of electricity produces 1 watt of combined heat and light. Heat would depend on efficiecy. But I think the difference will be minor. The reason the 315 are popular is probably because they pull less wattage than what was used before. The same as the Quantum boards I would imagine. The lower wattage produces lower heat. I can not imagine what a 1000 watt HPS must be like. It must be really hot.
 
N

Nutria

Well-Known Member
Light does produce heat even if absorbed by the plant for photosynthesis and transpiration, it is just easier to manage and exhaust humidity through air.
1w=3,412 BTU/h

or not?
 
GBAUTO

GBAUTO

Well-Known Member
...just a thought
Assume we are in a sealed environment-everything we add to that space remains in that space. The energy we add to produce PAR is used by the plant to grow-since I also agree with the conservation of energy, the question I have is if it takes energy to physically grow(create) a plant's structure then doesn't that get subtracted from the sum added by the light source? The best way I've been able to illustrate that is on a burn pile. It took photons of energy to grow a plant-if you burn the plant, that same energy is released as heat. The total amount of energy in a system is constant but how it is expressed(heat, light, plant) has an effect on temps..at least until your tent catches on fire.
 
gwheels

gwheels

Well-Known Member
Energy can not be created or destroyed. However even the photons used by your plants transpire heat. I have done a bit of research and really wattage is about the best indicator of heat. All of the transpiration and dissipation are so minor as to not effect the basic idea within a tent especially. 1 watt produces 3412 BTU but you might get it down to 3000 if you are running very efficient.

I am an almost newb just trying to find the solution. I think quantum boards and light are it. In that a 135 watt board can do what 200 watts of other light can.

I do not mean to get anyones back up. I am just curious about personal experience.
 
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V

VegasWinner

Well-Known Member
I use three 100w GrowGreen boards at 300w from the wall with Deep Red and royal Blue 10w diodes at 75w from the wall in a 2x4x6 tent. I use a filtered 4" exhaust fan nothing fancy two speed and no heat. three degrees between ambient air temps and tent temp.

it is about the efficiency of the fixture and not the diode. depending on heat sink, diode running current, and ambient temps, more than watts is at play.

With pcb's using LM561C diodes wired in the proper parallel/series arrangement can provide excellent results with no cob coming close to production, heat, and total energy consumption.

Most folks are going to buy a cob/pcb/fixture and need that kind of help.
 
R

Ryante55

Well-Known Member
gwheels said:
Lets say you have a 2 x 4 or a 2 x 3 x 6 foot tall tent

What do you think is the lowest heat option for that tent? Using a scrubber and such helps but heat is a big issue in a small space.

I have a 315 CMH i use in a 4 x 4 and it is manageable

I have a 200 watt vero i use in a 20 x 36 x 62 and it is now manageable but i had to dick around with my exhaust to make it work.

Would a 240 watt quantum board produce more heat than the 200 watt vero?

And 1 watt of light does not produce 1 watt of heat. Some of the light is used as energy for the plants. The more inefficient a light is the more heat it will produce. But it is not a linear equation.

How is the heat on your samsung quantum boards? I am really thinking about a 2 panel kit from timber and making a frame work to hold them sideways (so it is 24 x 7 inches for the frame roughly).
Click to expand...
If heats that big of a deal I would build a small grow box and use led with the heatsink coming out the top that would cut the heat in half.
 
R

Ryante55

Well-Known Member
GBAUTO said:
...just a thought
Assume we are in a sealed environment-everything we add to that space remains in that space. The energy we add to produce PAR is used by the plant to grow-since I also agree with the conservation of energy, the question I have is if it takes energy to physically grow(create) a plant's structure then doesn't that get subtracted from the sum added by the light source? The best way I've been able to illustrate that is on a burn pile. It took photons of energy to grow a plant-if you burn the plant, that same energy is released as heat. The total amount of energy in a system is constant but how it is expressed(heat, light, plant) has an effect on temps..at least until your tent catches on fire.
Click to expand...
So if you grow a plant longer it burns more because it got more light? I don't think that holds up maybe I just misunderstood what your saying.
 
GBAUTO

GBAUTO

Well-Known Member
What I am saying is that you need to consider the energy stored/released from the plant when it is burned. That amount of energy needs to come from somewhere.
 
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