ttystikk
Well-Known Member
Light hitting leaves also turns to heat; in this case, transpiring water into vapor and cooling the plant.
All LED Indoor Grow- Quantum Boards vs AutoCob's
- Thread starter Evil-Mobo
- Start date
ttystikk
Well-Known Member
No sir. Legal issues.
Evil-Mobo
Well-Known Member
Ah my apologies was not trying to pry.
ttystikk
Well-Known Member
I'm accused of the 'crime' of growing a harmless plant in the privacy of my own home.
In a legal state.
I have nothing to be ashamed of, my conscience is clear.
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Bosgrower
Well-Known Member
It would seem that we can't agree on the criteria of the test for a detailed comparison so ... I offer the following practical scenario
800w of unvented hps in a 5x5x7 tent with a 400cfm inline fan on a 24" carbon filter and an 8" intake duct
800w of 50w LEDs driven @ 1400ma ... all other criteria the same.
Drivers and ballast(s) outside the tent.
Ambient temperature outside the tents is 70 deg F @ 50% relative humidity.
I can attest to the fact that my tent with the LEDs maintains 77-80 deg F.
I don't have an HPS but from what I've read, it would make my tent significantly hotter.
800w of unvented hps in a 5x5x7 tent with a 400cfm inline fan on a 24" carbon filter and an 8" intake duct
800w of 50w LEDs driven @ 1400ma ... all other criteria the same.
Drivers and ballast(s) outside the tent.
Ambient temperature outside the tents is 70 deg F @ 50% relative humidity.
I can attest to the fact that my tent with the LEDs maintains 77-80 deg F.
I don't have an HPS but from what I've read, it would make my tent significantly hotter.
dstroy
Well-Known Member
https://en.wikipedia.org/wiki/Electrical_efficiency
It all ends up as heat eventually. The reason that we need heatsinks on the led array is because they are not 100% efficient at turning input energy into light. So however efficient they are, the rest gets turned into heat. And the more inefficient they are (driven harder) the more heatsink area you need. But like others have said 600w in = 600w heater pretty much.
The reason that some users can get their tent cooler is because they are getting the same amount of usable light from their newer lower wattage light that produces the same amount of light that their higher wattage lower efficiency light did.
You can't take away energy that you put into a system, it has to go somewhere. It ends up as heat.
It all ends up as heat eventually. The reason that we need heatsinks on the led array is because they are not 100% efficient at turning input energy into light. So however efficient they are, the rest gets turned into heat. And the more inefficient they are (driven harder) the more heatsink area you need. But like others have said 600w in = 600w heater pretty much.
The reason that some users can get their tent cooler is because they are getting the same amount of usable light from their newer lower wattage light that produces the same amount of light that their higher wattage lower efficiency light did.
You can't take away energy that you put into a system, it has to go somewhere. It ends up as heat.
Evil-Mobo
Well-Known Member
Thanks for the input brother.
I'm curious which would be better and why, and if the expense is worth it over a DIY setup like I already have..........
Humanrob
Well-Known Member
If you've got some time to kill...
Here's a link to a post he made about them in the SIP thread -- LINK
And here's a link to his initial grow thread -- LINK
The second is pages around his room and light build, but I think he also talks about his choice of Autopots.
I read most of this stuff late at night while I'm stoned, so my retention is not great.
Evil-Mobo
Well-Known Member
Perfect something to read. I'm caught up in the garden and with my journals for the most part so this will come in handy.
Thanks
coreywebster
Well-Known Member
http://www.earthonlinemedia.com/ebooks/tpe_3e/biogeography/trophic_levels_and_food_chains.html
Two laws of physics are important in the study of energy flow through ecosystems. The first law of thermodynamics states that energy cannot be created or destroyed; it can only be changed from one form to another. Energy for the functioning of an ecosystem comes from the Sun. Solar energy is absorbed by plants where in it is converted to stored chemical energy.
MMJ Dreaming 99
Well-Known Member
Do you have a nute problem or russet mites?
coreywebster
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!!
greg nr
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.
Bosgrower
Well-Known Member
I think the best way to resolve the issue with respect to the amount of heat and photons generated by various lighting technologies is to test them in empty environments where there are no biochemical issues to consider, the reflectivity / absorption of the enclosure surfaces is known, and the only variable would the changes in entropy.
I think a large part of the issue here has been that the energy absorption by the plant materials during photosynthesis and the energy release as heat during transpiration are muddying the waters.
greg nr
Well-Known Member
Maybe, except we don't light empty spaces, we light spaces filled with plants and expect the plants to thrive.
It would be an interesting test to put a 600 w cob rig into an empty tent and then 600w of IR heat lamp. What would the ambient temp diff be, if any? But it's just a curiosity. Add plants, and as you say, everything changes.