Real or scam?Cooling from 'sky'

• Real or scam?Cooling from 'sky'
  Posted by Raj on 09 Jul, 2018 05:30
• recently,I had this video popping up in youtube suggestion-
  I am quite suspicious it's gonna be like fontis or solar road or something,
  but at the same time, I think why would a phd guy destroy his reputation, conjuring up a hoax?
• #1 Reply
  Posted by larsdenmark on 09 Jul, 2018 10:50
• I have no problems with this tech and how it works. It has been published in Nature after all.
  
  Whether or not it'll be economically viable is another thing, but it looks promising.
  
• #2 Reply
  Posted by BrianHG on 09 Jul, 2018 17:18
• Discussed weeks ago here: https://www.eevblog.com/forum/chat/harnesing-cold-outer-space-on-the-ground-through-a-transparent-ir-wavelength/
  Everything you need to know is in the thread.
  And, it shouldn't be in the dodgy section.
  
• #3 Reply
  Posted by G7PSK on 10 Jul, 2018 08:33
• Nothing that new really.
  http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1938851
  
  Thermo siphon power generation using ocean water was proposed in the 60's not sure if any was put into action back then but the ASME paper of 2014 claims it is a first.
• #4 Reply
  Posted by IanMacdonald on 12 Jul, 2018 16:02
• This does work, and was used in ancient times to cool water or even make ice. 
  
  The unfortunate corollary for the climate alarmists is that it's the smoking-gun proof that carbon dioxide is not very effective as a greenhouse gas. If it were, then it would not be possible to cool water this way. 
• #5 Reply
  Posted by BrianHG on 13 Jul, 2018 13:54
• Quote from: IanMacdonald on 12 Jul, 2018 16:02

  The unfortunate corollary for the climate alarmists is that it's the smoking-gun proof that carbon dioxide is not very effective as a greenhouse gas. If it were, then it would not be possible to cool water this way. 
  

  Please provide the diffusion, absorbent, reflective and transparent spectrum wavelengths maps of CO₂ at atmospheric pressure so I may compare it to the graph provided in the video...
• #6 Reply
  Posted by tomato on 15 Jul, 2018 04:28
• Quote from: IanMacdonald on 12 Jul, 2018 16:02

  The unfortunate corollary for the climate alarmists is that it's the smoking-gun proof that carbon dioxide is not very effective as a greenhouse gas. If it were, then it would not be possible to cool water this way. 
  

  
  The guy does a pretty good job of explaining how the emitted radiation must be at a certain wavelength for this process to work.  In no way does it imply that CO2 is not an effective greenhouse gas.
• #7 Reply
  Posted by StillTrying on 15 Jul, 2018 14:04
• Quote from: tomato on 15 Jul, 2018 04:28

  The guy does a pretty good job of explaining how the emitted radiation must be at a certain wavelength for this process to work.

  
  At least one of us thinks he's wrong.
  https://www.eevblog.com/forum/chat/harnesing-cold-outer-space-on-the-ground-through-a-transparent-ir-wavelength/msg1629317/#msg1629317
• #8 Reply
  Posted by tomato on 16 Jul, 2018 23:24
• Quote from: StillTrying on 15 Jul, 2018 14:04

  
  At least one of us thinks he's wrong.
  https://www.eevblog.com/forum/chat/harnesing-cold-outer-space-on-the-ground-through-a-transparent-ir-wavelength/msg1629317/#msg1629317
  

  
  You disagree with the physics?
• #9 Reply
  Posted by StillTrying on 17 Jul, 2018 12:36
• "You disagree with the physics?"
  
  No, the explanation. I suspect it would work with the right type of reflector pointed in the right direction.
• #10 Reply
  Posted by IanMacdonald on 02 Aug, 2018 19:42
• Emitted radiation wavelength range of bulk solids or liquids is is determined by temperature. Essentially, black body law. (A white or transparent object emits less radiation than a black one, but still behaves as a 'black body' in terms of spectrum.)
  
  I don't see how that can be vastly different from the range emitted by the Earth's surface. Gases are not 'black bodies' though, and behave differently.
  
  Have a play with this to see how it works. The solid lines are the relative energy distribution by wavelength for an 'ideal black' solid object at a given temperature.