Plastic Film Cools Whatever It Touches up to 10°C

Discussion in 'HardForum Tech News' started by Megalith, Feb 26, 2017.

  1. Megalith

    Megalith 24-bit/48kHz Staff Member

    Messages:
    13,004
    Joined:
    Aug 20, 2006
    Two professors at the University of Colorado in Boulder have developed a film embedded with glass spheres that provides a passive cooling effect. Twenty square meters of the material would be enough to keep a room at 20°C in 37°C weather. The real kicker is that it is actually cheap to produce.

    A thin plastic sheet may soon provide some relief from the intense summer sun. The film, made from transparent plastic embedded with tiny glass spheres, absorbs almost no visible light, yet pulls in heat from any surface it touches. Already, the new material, when combined with a mirrorlike silver film, has been shown to cool whatever it sits on by as much as 10°C. And because it can be made cheaply at high volumes, it could be used to passively cool buildings and electronics such as solar cells, which work more efficiently at lower temperatures.
     
    Last edited: Feb 26, 2017
    griff30 likes this.
  2. thesmokingman

    thesmokingman [H]ardness Supreme

    Messages:
    4,772
    Joined:
    Nov 22, 2008
  3. mullet

    mullet [H]ard|Gawd

    Messages:
    1,629
    Joined:
    Aug 19, 2004
    GW solved!!!!!!
     
  4. sir-gold

    sir-gold Gawd

    Messages:
    931
    Joined:
    Jan 19, 2006
    I read the articles, and from the way it sounds, they have created a material that absorbs almost no enegry from the sun, and converts any heat it does absorb (from the things it is touching) into a form of IR that radiates all the way into space without heating the atmosphere on the way up.

    They are thinking WAY too small if they just want to cool some buildings. It seems to me that a big enough sheet floating on the ocean could directly counter-act ocean warming (unfortunately, based on the costs cited in the second article of $0.25/sqft, a 500 square mile sheet would cost $34 billion.)
     
    Wrecked Em likes this.
  5. Ultima99

    Ultima99 [H]ardness Supreme

    Messages:
    4,887
    Joined:
    Jul 31, 2004
    You are also thinking about this in the wrong way sir.

    When can I expect to see ATX cases and all my components lined with this stuff?

    We could see a new level of performance of passive only cooled devices as well.
     
    griff30, Inu and lironmiron like this.
  6. collegeboy69us

    collegeboy69us [H]ardness Supreme

    Messages:
    5,257
    Joined:
    Jul 27, 2003
    While cool -- it's at the same stage as every other "awesome new battery tech" article that pops up every 12 months for the past 10 years.

    Until it's mass produced and sold to consumers, there really isn't much that interests me. For all the articles that have tech like this, most never make it out of the lab phase because of this or that.
     
    griff30, Nukester and Wrecked Em like this.
  7. phrozenfayte

    phrozenfayte n00b

    Messages:
    32
    Joined:
    Apr 9, 2010
    Well that's the thing, it seems to just be glass dust mixed with pmp and one of those dodgy silver coatings you find on all those cheap plastic mirrors. All easily mass producible.

    When you normally go to make a lab sample of something, you produce a tiny piece, enough to show off the effect of what you're trying to achieve. Their lab sample seems to be a massive roll.
     
  8. sfsuphysics

    sfsuphysics I don't get it

    Messages:
    13,667
    Joined:
    Jan 14, 2007
    Well if it absorbs almost no energy from the Sun it's basically a super reflective mirror. Any heat it does absorb it gives off as IR because it radiates like a blackbody, which is something everything does, "unfortunately" our atmosphere naturally absorbs IR radiation at all wavelengths, so that last part is very hard to swallow.
     
  9. Nanogrip

    Nanogrip Limp Gawd

    Messages:
    429
    Joined:
    Dec 4, 2016
    It might cool a building, but not much, if everything around the building is hot (convection heat). I think it'll be great for electronic devices, control boxes, and other items that are in the sun for most of the day. Bulb reflectors too.
     
  10. -PK-

    -PK- [H]ard|Gawd

    Messages:
    1,798
    Joined:
    Aug 6, 2004
    They claim that it changes the IR wavelength to 8-13 microns not absorbed by most greenhouse gases. Indeed, it would miss CO2, CH4, and N2O, but it might react with O3 which has a peak IR absorption around 9.4-9.6 microns and quickly drops right at 10 microns. All of the O3 in the atmosphere measures a total radiative forcing roughly equal to methane (net contribution to warming the Earth), which is bad considering it's 1/45th the concentration of methane in the atmosphere. So how much of this IR misses O3 will be a significant factor.
     
    Last edited: Feb 27, 2017
    TheHobbyist and Schtask like this.
  11. Master_shake_

    Master_shake_ [H]ardForum Junkie

    Messages:
    8,231
    Joined:
    Apr 9, 2012
    no more a/c gonna need shit tonnes of heat though.
     
  12. Krenum

    Krenum [H]ardForum Junkie

    Messages:
    15,318
    Joined:
    Apr 29, 2005
    Sweet! I can finally cool my Skylake processor!
     
  13. geok1ng

    geok1ng 2[H]4U

    Messages:
    2,123
    Joined:
    Oct 28, 2007
    Someone has not heard about the second law of thermodynamics. Both Clausius and Kelvin statements are self explanatory in this context:

    Heat can never pass from a colder to a warmer body without some other change, connected therewith, occurring at the same time.
    It is impossible, by means of inanimate material agency, to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects.

    I am curious is how low has descended the knowledge of the so called tech journalists to make an article with such blatant absurds.
     
    Last edited: Feb 26, 2017
    Schtask likes this.
  14. Liver

    Liver [H]ardness Supreme

    Messages:
    4,351
    Joined:
    Oct 24, 2005
    What if I get a blanket made of this? Better yet, a pillow case.
     
  15. Travolta

    Travolta Gawd

    Messages:
    649
    Joined:
    Sep 19, 2004
    If they can come wrap my house in AZ with this stuff before summer, I'll help them test it.
     
    Liver likes this.
  16. Schtask

    Schtask Limp Gawd

    Messages:
    436
    Joined:
    Nov 29, 2011
    It's a transparent heat sink. From what they say, it sounds like it's only efficient if the heat source is making direct contact with it. But yes...If ambient temps aren't 10c less than the matter to be cooled, that would be a hard pill to swallow indeed.
     
  17. Schtask

    Schtask Limp Gawd

    Messages:
    436
    Joined:
    Nov 29, 2011
    I think rigid tubing with these properties could be pretty badass in a liquid cooled rig.
     
  18. sir-gold

    sir-gold Gawd

    Messages:
    931
    Joined:
    Jan 19, 2006
    It's not violating any laws, the thing you are missing is that the film isn't radiating the heat into the surrounding air, it's radiating it into space (which is colder than anything on earth)

    It's exploiting a (supposed) feature of our atmosphere which makes it transparent to a specific wavelength of IR, so as far as the material is concerned, the insulating blanket of atmosphere just doesn't exist.

    I thought it silly at first too, but if they are right about the IR transparency sweet spot, then there is no reason it wouldn't work.

    All objects radiate heat as IR all the time, and are constantly being hit with IR energy as well. When everything is the same temperature it all equals out, but if you radiate more IR than you absorb back, then you will lose heat.

    It's the same science that causes you to feel cold in the freezer section at the grocery store, even though the air temperature is the same: you are giving off more IR than you are getting back from the freezer doors.
    It's also the same reason why radiators and baseboard heaters are always placed against outside walls below the windows. Even if the air in the room is 70F, you will feel cold if one of the walls is radiating significantly less IR at you than you are radiating at it.

    There are 3 kinds of heat transfer: convection, conduction and radiation. It's very hard to manipulate conduction, but radiation can be manipulated to a high degree using precision particles (the size of the particle limits the specific wavelengths it can radiate at).

    If you can maintain conduction to draw heat from the object being cooled, reduce incoming radiation with one-way reflective coatings, and fine tune the outgoing radiation spectrum to avoid heating the air and causing convection, you would get a heat-pipe directly into the cold depths of space.

    Its not terribly different than the way a florescent light works, the gas inside the tube can only create UV light, but the phosphor coating on the glass absorbs the UV light and re-emits it as visible light. This is the same thing, except the film is absorbing energy in the form of heat, and re-emitting it as (a specific wavelength of) IR

    (most of this is paraphrased from the theory section of an HVAC/R textbook, if anyone doubts it.)
     
  19. geok1ng

    geok1ng 2[H]4U

    Messages:
    2,123
    Joined:
    Oct 28, 2007
    There is nothing magical about the 10 micrometers infrared radiation the film allegedly fine tunes the radiation. actually it is the mean human body emission for skin temperatures in the 33ºC range:

    So if our atmosphere has a 10 micrometers transparency window that allows for magical cooling, life on the planet has already evolved to radiate exactly on this infrared range. Humans radiate ~100w over a 2m² surface, the film claims 93w/m² . i can think of many cloths solutions more efficient than both alternatives: going naked or uisng a glass film. :cool:

    edit: this picture can help visualize what the earth atmosphere absorbs:
    [​IMG]
     
    Last edited: Feb 27, 2017
    TheHobbyist likes this.
  20. Kalabalana

    Kalabalana [H]ard|Gawd

    Messages:
    1,296
    Joined:
    Aug 18, 2005
    Accidental nano tech!
    I hope they localize the sub atomic process, since the material apparently isn't temperature locked. This means the theoretical upper limit of radiated heat being converted to ir most likely is much higher than 10 degrees if we could maximise the underlying mechanic.
    Quantum physics ftw
     
  21. DeathFromBelow

    DeathFromBelow [H]ardness Supreme

    Messages:
    7,106
    Joined:
    Jul 15, 2005
    Well, yeah. What's so surprising about that? Life has also already evolved brains, the most powerful computers on the planet. Natural selection optimizes life to it's environment.
     
  22. knowom

    knowom Limp Gawd

    Messages:
    419
    Joined:
    Aug 15, 2008
    They should sandwich thermoelectric generator's to one side of it and solar panels and a sheet of glass on the other side they could generate a lot of energy between the two things especially if it were done on the ocean one side being cool one side being hot the TEG's would work great and you get the solar benifits naturally as well hell toss in tidal energy along with wind and you've got a perfect storm of energy generation in the most open and vast area of under utilized spaces on Earth in large part. It would also work rather favorably in virtually any location deployed lots of sun great lots of cold water to cool it better solar panel efficiency and TEG efficiency and that's w/o getting into wind and tidal.
     
  23. sir-gold

    sir-gold Gawd

    Messages:
    931
    Joined:
    Jan 19, 2006
    This film isn't for cooling a person directly, it's for cooling the air inside a building.
    Also, according to to your numbers (unless it was a typo), the film radiates almost the same amount of heat, with half the surface area (100w/2m^2 vs 93w/m^2), which should make it twice as effective as bare skin