For all those off topic posts.

JohnFonda

JohnFonda

Tegrity Greenthumb
@TreeFarmerCharlie @sfrigon1 @Hust17 . Here we are. Now no disrupting other threads lol. Treefarmer you are correct about the law of conservation of energy. However it doesn't apply to grows cause they are not closed systems. The light is absorbed by the plants and most is converted into usable energy which helps the plant grow etc. The energy isn't lost it's just changed. The hps produces more heat and the led produces more light per watt. That's the basis of the argument for me.
 
treefarmercharlie

treefarmercharlie

🍆
Admin
JohnFonda said:
@TreeFarmerCharlie @sfrigon1 @Hust17 . Here we are. Now no disrupting other threads lol. Treefarmer you are correct about the law of conservation of energy. However it doesn't apply to grows cause they are not closed systems. The light is absorbed by the plants and most is converted into usable energy which helps the plant grow etc. The energy isn't lost it's just changed. The hps produces more heat and the led produces more light per watt. That's the basis of the argument for me.
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I get that, but a good portion of that light is not converted by the plant and is also absorbed, in the form of heat, to non reflective (and reflective) surfaces in the tent. I really wish I could find that damn article because it explains what I'm trying to describe extremely well. The reason we get less heat from LED, compared to HPS, is because we can get away with running less watts to provide a similar amount of light. This is why I was comparing a 300W LED with a 300W HPS (not a 300W HPS with a LED equivalent to a 300W HPS). Does that make any sense?
 
sfrigon1

sfrigon1

Seed Aficionado
JohnFonda said:
@TreeFarmerCharlie @sfrigon1 @Hust17 . Here we are. Now no disrupting other threads lol. Treefarmer you are correct about the law of conservation of energy. However it doesn't apply to grows cause they are not closed systems. The light is absorbed by the plants and most is converted into usable energy which helps the plant grow etc. The energy isn't lost it's just changed. The hps produces more heat and the led produces more light per watt. That's the basis of the argument for me.
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The fuck u drag me into this for lol
 
Oreguhnism

Oreguhnism

Really Active Member
Hps produces convection 895 nm = IR Heater so heat is almost exclusively produced in front of the source.

Led utilizes conduction and convection. Most leds lack IR so convection as a point source is definitely less aka most people raise their led grow room temps in a lot of cases especially winter. Heatsinks conduct waste heat for most part. Like an oil heater slowly achieves an all around warmth doesnt just blast a single point source with convect....


Thats my 2cent.
I can go into thermal equations if you like. I taught myself thermo whatevers,a little bit to build all my LED fixtures. Always inspired by Stardust sailor, an original bad ass.
 
JohnFonda

JohnFonda

Tegrity Greenthumb
TreeFarmerCharlie said:
I get that, but a good portion of that light is not converted by the plant and is also absorbed, in the form of heat, to non reflective (and reflective) surfaces in the tent. I really wish I could find that damn article because it explains what I'm trying to describe extremely well. The reason we get less heat from LED, compared to HPS, is because we can get away with running less watts to provide a similar amount of light. This is why I was comparing a 300W LED with a 300W HPS (not a 300W HPS with a LED equivalent to a 300W HPS). Does that make any sense?
Click to expand...
Makes perfect sense yes except a good portion of light not being absorbed by the plants. If that's the case couldn't you just use less light so a good portion is absorbed ?
 
sfrigon1

sfrigon1

Seed Aficionado
JohnFonda said:
Makes perfect sense yes except a good portion of light not being absorbed by the plants. If that's the case couldn't you just use less light so a good portion is absorbed ?
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Even if u have the same lux showing, it's dif light . Different in many ways. Ur Radiant penetration
 
JohnFonda

JohnFonda

Tegrity Greenthumb
sfrigon1 said:
Even if u have the same lux showing, it's dif light . Different in many ways. Ur Radiant penetration
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Even in that sense I still think the led produces more usable light which in turn will run cooler having more energy absorbed. Not only that the radient heat from hps is pointing straight down on your ladies heating them up. I understand not all light is usable for photosynthesis but they have been designed to the best of our ability to produce light in the most usuable spectrums. LEDs especially. If anyone can find the numbers for wasted light please throw them up I'm curious. I'll be looking too.
 
treefarmercharlie

treefarmercharlie

🍆
Admin
JohnFonda said:
Makes perfect sense yes except a good portion of light not being absorbed by the plants. If that's the case couldn't you just use less light so a good portion is absorbed ?
Click to expand...
This is what I’m interested in learning about but none of us seem to really know. I know the plants will only use specific temps of light, and not necessarily all of that, because it will only take in the light that hits the leaves and the whatever comes back from the light bouncing from surface to surface. The leaves will also still convert some of that light to heat, from any radiation that comes from the light, although LED emits less radiation than HPS.

I don’t think the difference is big, but it’s still very interesting to me, because I enjoy learning weird shit like this. I will admit I suck at equations, though.
 
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