All LED Indoor Grow- Quantum Boards vs AutoCob's

Roger A. Shrubber

Well-Known Member
if you convert energy into work, the work passes that energy along as friction, resistance, impact, w/e, most of which dissipate as heat....you can't win....the law is the law....if it goes in, it comes out. ask any physics teacher. if you put 100 watts into a light, its going to come out as 100 watts of heat. i'm really not trying to be a dick, or even argue. i realize it sounds wrong, but its right, and until you accept that, you'll never get the math right. try putting a 1000 watts worth of cobs in an area that had a 1000 watt hps in it, wait a few hours, and see what happens. its easily provable if you have the equipment. the test with the black spot above was invalid, unless you want to know the temperature of a black spot. if they would have put an ambient thermometer in that space and waited long enough, they would have read the same.
as photons degrade, they turn into heat...even the wind from your fans eventually turns back into heat....
 

greg nr

Well-Known Member
if you convert energy into work, the work passes that energy along as friction, resistance, impact, w/e, most of which dissipate as heat....you can't win....the law is the law....if it goes in, it comes out. ask any physics teacher. if you put 100 watts into a light, its going to come out as 100 watts of heat. i'm really not trying to be a dick, or even argue. i realize it sounds wrong, but its right, and until you accept that, you'll never get the math right. try putting a 1000 watts worth of cobs in an area that had a 1000 watt hps in it, wait a few hours, and see what happens. its easily provable if you have the equipment. the test with the black spot above was invalid, unless you want to know the temperature of a black spot. if they would have put an ambient thermometer in that space and waited long enough, they would have read the same.
as photons degrade, they turn into heat...even the wind from your fans eventually turns back into heat....
Not exactly true. Both work and heat are energy. "When energy is exchanged between thermodynamic systems by thermal interaction, the transfer of energy is called heat". "Work is the transfer of energy by any process other than heat."

So you can transfer energy and not produce heat. A chemical reaction is the transfer of energy. So this isn't work in the sense that a force is exerted over a distance, but it is work in that energy is transferred without the conversion to heat.

And yes, work "can" be completely converted to heat, but a chemical reaction can avoid that, at least for a while. So if more of the energy is in the form of photons rather than heat, and those photons are used to fuel photosynthesis, less heat will be produced.

It's an energy balance. Take the plants out and the balance doesn't change, it just presents itself differently.
 

dstroy

Well-Known Member
I'm not sure I agree with you 100%.

Light is energy, not heat (despite what the grow boss says). Energy can be converted into work or heat. In the case of photosynthesis, it is used to produce sugars and O2 from light, CO2, and H2O. That is work. Any energy used to produce work doesn't necessarily produce heat (a chem reaction could be endothermic).

So the energy balance is still maintained, but all 600 watts don't end up as heat. An hps light works by first heating a gas. So heat is part of it's design from the outset, plus it consists of 15% infra red, which converts to heat very easily. You can see this with a thermometer pointed at the leaves. The canopy under hps is hotter than under led.

On balance, I still prefer LED's for small tents. And not just because you need fewer watts. I'd gladly replace a 400 w hps with a 400 watt cob or qb design.
A 600w led is going to produce the exact same amount of heat as a 600w hps, and I explain why below.

Let's talk about lumen/watt, or electrical efficiency when comparing led/hps since we are only concerned with how much heat they produce in this discussion.

I'm not trying to go down the rabbit hole of what percentage of the energy gets turned into heat, because all of it is eventually converted to heat at some point by one process or another.

Converting energy into light is not 100% electrically efficient. Most of the energy that doesn't get turned into light becomes heat.

Natural processes are not 100% efficient, and they also create heat because of inefficiency. Using stored chemical energy creates heat. Storing chemical energy can release or absorb heat.

https://www.scientificamerican.com/article/how-exactly-does-light-tr/
Surfaces (leaves) absorb photons which turns into heat. They transpire and lose heat through evaporative cooling.

Even when light hits something reflective, not all of the light is reflected. So that surface is not 100% efficient at reflecting light, the rest is absorbed as heat.

What I am saying, is that if you have a 600w light fixture, and 200w of fans, that you will have 800w of heat that is going to need to be extracted.

LED arrays do not create a lot of "forward heat" Like an HPS bulb does so my theory is that it is easier to extract the heat from LED lights because it is localized which leads to cooler temperatures inside of the tent.
 

Evil-Mobo

Well-Known Member
Hey Evil-Mobo, I have not used those Octopots but I have used Autopots. Autopots are ok, they work a bit like a toilet ballcock, once the water has been soaked up to the point the tray is dry the valve releases and allows more water in.
They did ok on root mass but most of the mass was at the bottom of the pot where the water wicks up. Roots where healthy and white. But compared to hand watering cloth pots they don't compare in root mass alone. Pre using Autopots I hand watered in plastic pots mainly. I didn't see an advantage in plant growth nor in yield. The advantage for me was just not having to water every 2-3 days. The disadvantage was the narrow tubing and fittings clogging up from salts and hardening blocking the valves sometimes.
The work around to that is to replace with the thicker tubing and fittings which apparently solves the problem.
I stopped using them after several harvests because they allowed me to be lazy and not pay full attention to my plants, not getting so up close and personal with them. Plus I did have an issue with clogging valves which when not amongst the plants was easy to miss and a couple of plants wilted to the point of dropping all fan leaves.

Those Octopots look good. But have not used them. So cant add anything useful other than the pictures on the website show a far bigger root mass than with Autopots.

Also, I would like to apologise for distracting from your thread with the whole "all light turns to heat eventually" debate.

Keep up the good work and heres wishing you happy harvests now and in the future!! :bigjoint:
Thanks for the feedback I'm leaning towards the octo pot even more now if I decide to try something else. My diy SIP's just seem to be doing fine but we will see after this run.
 
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coreywebster

Well-Known Member
A 600w led is going to produce the exact same amount of heat as a 600w hps, and I explain why below.

LED arrays do not create a lot of "forward heat" Like an HPS bulb does so my theory is that it is easier to extract the heat from LED lights because it is localized which leads to cooler temperatures inside of the tent.
100% sunlight → non-bioavailable photons waste is 47%, leaving
53% (in the 400–700 nm range) → 30% of photons are lost due to incomplete absorption, leaving
37% (absorbed photon energy) → 24% is lost due to wavelength-mismatch degradation to 700 nm energy, leaving
28.2% (sunlight energy collected by chlorophyl) → 32% efficient conversion of ATP and NADPH to d-glucose, leaving
9% (collected as sugar) → 35–40% of sugar is recycled/consumed by the leaf in dark and photo-respiration, leaving
5.4% net leaf efficiency.

This ^ is based on the sun. But by having a different spectrum, less IR and more light in the photosynthetic ranges of chlorophyll A and B as well as the other processes going on, the leaf efficiency should be higher. The difference between the wasted energy made from the spectrum of HPS vs White light of Cobs is a fair bit so the leaf efficiency difference should be considerable and if it is the difference in how many photons get converted into chlorophyll and how much ends up as heat in the grow room should also be enough to measure.

If all energy is converted to heat (in our grow room) then how do you explain the energy released as heat when we smoke a bong and our buds turn to ash? Since energy cannot be created or destroyed. It has been chemically stored and in burning we convert that energy again.
 

dstroy

Well-Known Member
100% sunlight → non-bioavailable photons waste is 47%, leaving
53% (in the 400–700 nm range) → 30% of photons are lost due to incomplete absorption, leaving
37% (absorbed photon energy) → 24% is lost due to wavelength-mismatch degradation to 700 nm energy, leaving
28.2% (sunlight energy collected by chlorophyl) → 32% efficient conversion of ATP and NADPH to d-glucose, leaving
9% (collected as sugar) → 35–40% of sugar is recycled/consumed by the leaf in dark and photo-respiration, leaving
5.4% net leaf efficiency.

This ^ is based on the sun. But by having a different spectrum, less IR and more light in the photosynthetic ranges of chlorophyll A and B as well as the other processes going on, the leaf efficiency should be higher. The difference between the wasted energy made from the spectrum of HPS vs White light of Cobs is a fair bit so the leaf efficiency difference should be considerable and if it is the difference in how many photons get converted into chlorophyll and how much ends up as heat in the grow room should also be enough to measure.

If all energy is converted to heat (in our grow room) then how do you explain the energy released as heat when we smoke a bong and our buds turn to ash? Since energy cannot be created or destroyed. It has been chemically stored and in burning we convert that energy again.
Well, to be fair I did say it will be converted to heat at some point or another. And I also said that using stored chemical energy releases heat.

I don't know what you are arguing about.
 

ttystikk

Well-Known Member
One big heat sink in a grow room is transpiration, maybe the biggest.

But the article linked above definitely showed different temperatures from different light types. Would this be due to different spectra emitted, different amounts of IR or?
 
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coreywebster

Well-Known Member
Man it sucks to scroll past all these stupid posts about heat just don't buy led if you think hps is just as cool...the end back to growing please
Its called a discussion, no one is been arsey with each other. The point was not that HPS is as cool as LED, pretty sure all of us grow with LED who were discussing it.
Although it isn't the right place to have this discussion. I'm pretty sure this doesn't come across as the usual LED Vs HPS argument which used to fill these forums, full of throwing insults at each other ect.
But fair enough, let us end it at that and let E.M get back to doing his thang.
 

Evil-Mobo

Well-Known Member
The discussion has not bothered me at all because it has been kept civil. As long as it stays that way it's cool with me because it is a topic that interest me anyways. And I have grown with both and at my last place ran a 1K watt on half a 5x9 and a 700w DIY COB light on the other half so it's interesting to me to see theory on this topic and compare to what I experienced.

I am all for an active thread and don't mind any topic as long as it's civil. When we can all share info and no one is fighting that's when the learning happens :)
 

Yodaweed

Well-Known Member

Evil-Mobo

Well-Known Member
Did an initial trim on some buds that were hanging for a week or so already, got them in jars. It was both of my deep blue C autos from Mephisto, one was hydro and one was soil after the cure we will see what taste better..........both of these plants were grown under the AutoCob's start to finish.

IMG_20170605_201019.jpg IMG_20170605_202009.jpg
 

Evil-Mobo

Well-Known Member
That dbc is a frosty fkr bongsmilie
Yes low yield but VERY potent. First strain to help me get to sleep and get sleep in 3 years and she's not even cured yet lol. Good thing I grew 2 of them because she does yield low but the quality is nuts.

Can't wait to try the chemdogging and Narcotic kush too.........

After the SBA run going on in this thread for the 2 lights then the breeding madness will begin :fire:
 

GroErr

Well-Known Member
Yes low yield but VERY potent. First strain to help me get to sleep and get sleep in 3 years and she's not even cured yet lol. Good thing I grew 2 of them because she does yield low but the quality is nuts.

Can't wait to try the chemdogging and Narcotic kush too.........

After the SBA run going on in this thread for the 2 lights then the breeding madness will begin :fire:
I'll take quality over quantity anytime :joint:
 
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