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Anti-Frostidigitation: Heatpipe Gloves
Hettinga writes "A little casemod couture this morning, courtesy of Hongbin Ma, a professor of Mechanical and Aerospace Engineering at the University of Missouri. He has developed heatpipe-driven gloves which pump therms from your toasty upper arm down to those aforementioned frosty digits. 'Each glove contains five small heat pipes, one for each finger, that are about 14 inches long and 1 mm x 2 mm in the cross section. Each pipe consists of three sections: an evaporating section, which is attached to the upper arm area; an adiabatic section, which is between the finger area and the arm area; and the condensing section, which is attached to the finger area.' Coming soon to a half-pipe near you..."
He has developed heatpipe-driven gloves which pump therms from your toasty upper arm down to those aforementioned frosty digits.
If he has 'developed' these gloves, I would like to see a picture of them. It looks like these are just as 'developed' as those night-vision contacts over at Popular Science.
Nope. Heatpipes use a fluid and working pressure such that the fluid is almost-boiling at the optimum operating temperature. Heat one end, and the fluid boils, vapor diffuses rapidly to the other end, condenses giving up heat of vaporization, and is absorbed into the wick that runs through the pipe. It then goes back to the other end by capillary action.
That said, it IS more efficient if the bottom end is the "hot" end, 'cause the rising warm fluid vapor and the down-flowing condensed fluid are both assisted by gravity. However, gravity is NOT an essential part of the process (some satellite instruments use heatpipes to keep-em cool in free-fall, for example).
A friend of mine does heat pipes as a business: koolpipes.com
"My strength is as the strength of ten men, for I am wired to the eyeballs on espresso."
A lot of readers seem to be missing the point here. The real advantage of this prototype is that it's passive - no batteries, no chemical reactions, nothing. It keeps your fingers warmer by absorbing some heat from your body (that would eventually have ended up in the air) and transferring the heat to your fingertips.
So yes, hand warmers are cheap and effective, but they'll die after a few hours once the reaction finishes.
Keeping your core temp high is a nice idea, but let's say you already have a nice coat and things - I think having some gloves that would passively heat my fingers would be nicely appreciated. Their was a post about how if it's a matter of life-or-death, you should maintain your core temp, but I think the more realistic application of these gloves would be to maintain comfort of your digits when you know you're going to be outside.
Again, the system is passive - no batteries, no chemical reactions, nothing at all. You'd put them on and forget about it.