Personal air conditioning units

Discussion in 'Off-Topic' started by #12, Aug 24, 2014.

  1. #12

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  2. Brownout

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    Jan 10, 2012
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    This is actually great news. I used to wear the old charcoal filled NBC suits (Nuclear, Biological and Chemical) and I thought there is absolutely not way in hell I could fight in that git-up. It was so hot, I would die of heat stroke in a matter of minutes. Now, of course, along this personal chillers, the amount of junk the soldier had to carry into battle is going to overwhelm him. But soon he will have the strength of 100 men via the exoskeleton.

    And don't worry, these units will need fixin' too.
     
  3. Wendy

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    And there will be more of them.
     
  4. nerdegutta

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    Could it be used to warm a soldier too? For the ones living in the arctic, lots of clothes makes you sort of immobile.

    I remember some of the excercises I've done in the cold weather with lots of clothes on. Not an easy take to lie down, change mag and then get up to continue firing.
     
  5. #12

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    That's why I live in Florida. :D
     
  6. #12

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    Second take: If you want a heat pump optimized for 0 F and below, I'm sure the military budgets can work on that. My experience is with heat pumps optimized for 30 F and up.
     
  7. JoeJester

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    Apr 26, 2005
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    #12,

    I didn't know they made the personal cooling devices cheap enough to be throwaways. There will be trained service professionals working on those systems, and like all other "military" researched systems, will someday be on the public marketplace.

    Your job is safe for awhile.
     
  8. tcmtech

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  9. #12

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    I wasn't serious about losing my job to personal air conditioners. Just look at that fashion apparel! Women would never wear them unless it gets to 140 F degrees outside. :D
     
  10. inwo

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    Nov 7, 2013
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    Wouldn't a peltier wrist device make more sense? Or helmet?

    A friend of mine who works in the heat, has a habit of blowing on his wrists for cooling.
     
  11. #12

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    You must live in Minnesota. :D You can't move that much heat out of your wrist. You're lucky if a whole vest is good enough. As the article said, 110 feet of tubing.

    This system uses 120 watts. Imagine strapping a resistor on your wrist and heating it with 120 watts.:eek:
    It's almost as ridiculous to try to do that with cooling.
     
    Last edited: Aug 25, 2014
  12. GopherT

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    Nov 23, 2012
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    You can easily remove that much heat from your hand. There is a medical device for putting heat back in. You put your hand into a machine with a snug cuff, it pulls a slight vacuum to expand the capillaries and arteries in your hand and improve blood flow, a warm fluid is pumped past the hand. Person is warm in minutes.

    Now, Stanford biologists are looking at cooling the same way...
    http://news.stanford.edu/news/2012/august/cooling-glove-research-082912.html
     
  13. gerty

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    Not air conditioning but it cools quite well...http://coolshirt.com/emergency/
    Our Rope Rescue trainer got one of these systems recently and loves it.

    She posted some pics of it in use last week, said it was 110 degrees out. 3 people had the vests on and they were the only ones in the pic smiling. I've not seen them personally, but in the pics it looked like they were running 3 vests from one cooling unit.
     
  14. #12

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    Very interesting, Gopher. Still, it has some limitations, like stopping whatever you're doing or at least forfeiting the use of a hand to keep doing what you want to do. Another aspect is that the time rate of cooling wasn't stated. The article said you can't use a lower temperature than the local vasoconstriction temperature, and that's a limit.

    This is the same principle as taking a shower that's just a little cool. If you use really cold water, like Minnesota water, your skin protects your core from dumping heat. That feels confusing. "My back is freezing and I'm still sweating on my face". If the shower is only comfortably cool, it works better.

    As for a helmet or a Peltier device, the military just finished all that testing and they decided on, "the same technology that's in your air conditioner". If you can top that, open a bank account for the money you're going to make!
     
  15. Sparky49

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    Jul 16, 2011
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    Interesting.

    Perhaps the full suit aims to actually reduce the temperature of the core, whilst the other methods aim to create the feeling of being cool. Like when you put one hand in cold water, the other in hot, then put them both in warm water, one feels hot the other cold.
     
  16. #12

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    The Stanford link by Gopher explains that certain molecules deform gradually up to 104 F where they fail completely in order to stop hard headed people (like me) from roasting their brains. The failure of this energy conversion molecule in the muscles stops you from functioning. Fixing the temperature enables continued activity without damaging your body. It isn't a matter of perception, it's a matter of temperature.

    The methods mentioned here all go directly at the temperature problem.
     
  17. tcmtech

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    I am quite aware of the ability for a persons hands to work as heat sinks or sources to warm or cool the body.

    I have done this for years as a standard winter strategy keep warm by holding on to a diesel exhaust pipe or hot hydraulic line or radiator hose when working out in the cold with equipment. ;)

    When cold putting your hands on something that is just below burning hot warms the whole body if given some time.


    It also works the same in the summer when dipping your feet in a cool pool of water for a bit. Once your body becomes accustomed to the heat transfer concept it only takes minutes of exposure to a cool direct contact source for the body to start dumping excess heat to that area. :)

    Personally if I was going to design a system I would heat with my feet and cool with my mid torso.
     
  18. #12

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    You take care of North Dakota, I'll be in Florida.
    That kind of cold makes me want to hide in a corner and fear for my life!
     
  19. wayneh

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    I'm about to head out for a run and it's hot enough here to be a problem. In the past I've often wondered if heat exchangers could help cool a runner, and imagined myself wearing an aluminum collar like a spiked dog collar. If not for the weight and cumbersome factors, I bet aluminum with a lot of surface area could move more heat to ambient than just sweating, although that's awfully effective. But at high humidity, the effectiveness of sweating goes down a lot.
     
  20. JoeJester

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    http://industrialsafetygear.com/hard-hats/940.html

    I had a similar cooling neckerchief in western Oklahoma when the heat was 100+ and I was working outside. My neighbor, who was a lineman for the electric company saw them and bought two, on to remain on ice while the other was in use. He also carried about 10-20 gallons of ice water with him on the truck.

    I think I might buy a couple now that I'm back in the weather that can be 100+.
     
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