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Originally posted by @joe-shmo
lets go over a few things.
In order for this to work all the heat from the load has to leave the system. Agree/ Disagree?
All the heat from the load is IR. Agree/Disagree?
IR is IR is IR. Agree/Disagree?
According to NASA only 6% of IR is [b]directly radiated to space without being absorbed by the atmosphere. Agree/Disagree?
If its too ...[text shortened]... object so special that 100% is radiated directly to space, as opposed to the standard 6%?[/b]
In order for this to work all the heat from the load has to leave the system.
NO NO that is completely false. Why "all" the heat?
Just SOME heat leaving will have a cooling effect.
In fact, the laws of thermodynamics imply it is impossible for ALL the heat to leave ANY material, and that includes from ANY part of a cooling system because absolute zero is impossible to reach. And yet that doesn't stop a cooling system from working like you imply here.
IR is IR is IR. .... IR is IR is IR.
are you trying to confuse the different forms of heat?
According to NASA only 6% of IR is directly radiated to space without being absorbed by the atmosphere
yes. Relevance?
If its too cool to give off its heat by conduction/convection with its surroundings ( which may be plausible) it is giving off nearly 100% of its heat (IR) as radiation.
why "nearly 100% " as radiation necessary for there to be a cooling effect? Why not just, say, 5% ?
Where is the other 94% of the IR being radiated to?
who said the rest is radiated? Who denies conduction?
I still don't see your point.
Do you deny that this cooling system can work? If so, explain why it wouldn't work since it works in nature. If not, then what's your point of contention?
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Originally posted by @humythe heat from the load has to leave the system.
In order for this to work [b]all
NO NO that is completely false. Why "all" the heat?
Just SOME heat leaving will have a cooling effect.
In fact, the laws of thermodynamics imply it is impossible for ALL the heat to leave ANY material, and that includes from ANY part of a cooling syst ...[text shortened]... ain why it wouldn't work since it works in nature. If not, then what's your point of contention?[/b]
In order for this to work all the heat from the load has to leave the system.
NO NO that is completely false. Why "all" the heat?
Just SOME heat leaving will have a cooling effect.
In fact, the laws of thermodynamics imply it is impossible for ALL the heat to leave ANY material, and that includes from ANY part of a cooling system because absolute zero is impossible to reach. And yet that doesn't stop a cooling system from working like you imply here.
Why does it have to give off its heat...to be a good heat exchanger! If a body is picking up heat and not releasing it what is happening to the body? Don't think to hard on this one humy, its a real brain teaser.
Next: If the body is heating up ( assuming you got the last question correct...I have my doubts) what is happening to the rate of heat transfer between the load and the body? Hint: see next line.
If the heat transfer rate between the load and the body goes to zero the system is not transferring heat! i.e. its not working!
That is why all the heat from the load must be dissipated.
why "nearly 100% " as radiation necessary for there to be a cooling effect? Why not just, say, 5% ?
See explanation above.
who said the rest is radiated? Who denies conduction?
After thinking about it, I do! In order for this thing to work the region under the reflective surface must be cooler than its surroundings. Heat does not spontaneously flow from cool to hot. Thus it cannot be conducting/convecting to the warmer atmosphere immediately in contact. That would violate the Second Law of Thermodynamics. It must be radiating to the next coolest thing (clouds, upper atmosphere, etc...).
Do you deny that this cooling system can work?
No, I already said this multiple times. I'm questioning how it works but your explanations of it are weak and full of thermodynamic holes that must be filled by reason before I jump onboard. If you don't have the answers, just say "I don't have the answers". Quit trying to feed me bologna and call it a steak!
Why does it have to give off its heat...to be a good heat exchanger!
nobody said/implied it doesn't give off heat.
If the heat transfer rate between the load and the body goes to zero the system is not transferring heat! i.e. its not working!
nobody said/implied it doesn't give off heat.
Heat does not spontaneously flow from cool to hot.
And nobody said/implied the contrary.
It works by transferring heat from the surface to the cooler outer space.
I'm questioning how it works but your explanations of it are weak and full of thermodynamic holes
I disagree; I for one see no holes in the explanation.
Originally posted by @humyWell...its pretty easy not to see when your blind.
Why does it have to give off its heat...to be a good heat exchanger!
nobody said/implied it doesn't give off heat.If the heat transfer rate between the load and the body goes to zero the system is not transferring heat! i.e. its not working!
nobody said/implied it doesn't give off heat.Heat does not spo ...[text shortened]... d full of thermodynamic holes
I disagree; I for one see no holes in the explanation.
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Originally posted by @sonhouseNo, I'm not saying such a system will not work. What I'm saying is the level of resolution on "how" it works provided by humy is unacceptable. I'm saying there is no way 100% of the heat is radiated directly to space from this device. I'm saying a large portion ( most likely larger portion) is radiated to the atmosphere. It is the next coolest thing, full of greenhouse gases and water vapor. A significant portion of the IR heat dissipated from the load is going to be absorbed and radiated by the atmosphere. You either believe that, or you believe the greenhouse effect is not real. Baring a deeper explanation of the mechanism they cannot be simultaneously true. Take your pick.
Are you saying such a system will not work?
Look at this graphic. Atmospheric opacity by wavelength. Infrared 0.7µm - 1mm.
https://en.wikipedia.org/wiki/Electromagnetic_radiation#/media/File:Atmospheric_electromagnetic_opacity.svg
In that band do you see any 0% opacity? The best I see is a narrow band between maybe 8µm - 30µm. If this material emits IR within only this band ( witch it undoubtedly doesn't - but may emit across the band to utilize it), the best case is "maybe" 70% radiated to space, but is likely worse than that.
You see, I say the dissipated heat it warms the atmosphere, and humy says it goes directly to space without warming the atmosphere.
Originally posted by @joe-shmoI can't believe all the heat escapes to space. maybe on the moon with no atmosphere or even on Mars with 1/100th Earth atmosphere but Earth, 14.7 PSI? But even if the number is only 50% radiated to space, it should still cool down the room underneath.
No, I'm not saying such a system will not work. What I'm saying is the level of resolution on "how" it works provided by humy is unacceptable. I'm saying there is no way 100% of the heat is radiated directly to space from this device. I'm saying a large portion ( most likely larger portion) is radiated to the atmosphere. It is the next coolest thing, f ...[text shortened]... it warms the atmosphere, and humy says it goes directly to space without warming the atmosphere.
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Originally posted by @sonhouse"I can't believe all the heat escapes to space" Correct - because it doesn't - directly.
I can't believe all the heat escapes to space. maybe on the moon with no atmosphere or even on Mars with 1/100th Earth atmosphere but Earth, 14.7 PSI? But even if the number is only 50% radiated to space, it should still cool down the room underneath.
Yes, there will be some measure of cooling regardless of the percentage between atmosphere and space. If the heat is being dissipated the heat is being dissipated.
Originally posted by @joe-shmoOne point I just thought of: suppose a system is worked out to have roof panels radiate heat, cooling the interior of the building. The thing I see is those panels competing for real estate with solar panels. I wonder if a system could be built that would still allow generation of energy and still radiate heat into space? Looks like that would be a win win, eh.
If your wondering why I engaged in this war of attrition over these subtle points. I think the thread posed coincidentally a few days ago by vivify with John Oliver explains it well enough.
https://www.redhotpawn.com/forum/science/john-oliver-on-scientific-studies.174138/page-1
Originally posted by @sonhouseI wondered the same thing. In theory, the is no reason to think that would be impossible because it wouldn't violate any physical law. However, in practice, it would have to be extremely efficient at converting the light energy into electric else any significant heat generated from light being converted to heat energy would render it completely useless as a cooling system; at least during the daytime.
I wonder if a system could be built that would still allow generation of energy and still radiate heat into space?
I am not sure how long it would be until we can make solar panels something like ~99% energy efficient at converting the light energy they absorb (so ignore the light they reflect) into electricity!
Originally posted by @humyIf you could get that kind of efficiency, that would cool in itself, when the energy is stored in some kind of battery, whatever the means, it would seem underneath all that would have to cool down automatically since there would be no energy or very little energy left to warm the building. A pipe dream anyway, at least in THIS millenium🙂
I wondered the same thing. In theory, the is no reason to think that would be impossible because it wouldn't violate any physical law. However, in practice, it would have to be extremely efficient at converting the light energy into electric else any significant heat generated from light being converted to heat energy would render it completely useless ...[text shortened]... at converting the light energy they absorb (so ignore the light they reflect) into electricity!