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The domestic refrigerator is a simple thing. A motorized
compressor
pumps the cooling gas around a looped pipe, and the pipe has a
narrow constriction at one point.
Upstream of the constriction, the gas is compressed and becomes
hot; the excess heat is dissipated by cooling fins on the back
of the
fridge. As the pipe passes into the fridge, the gas goes through
the
constriction, and the pressure is relieved. The gas expands, and
cools, which is what cools the fridge.
Now, consider, if you will, the humble running shoe. It takes a
terrible pounding, and often has air chambers built into the heel
to
absorb some of this impact. I submit that an air chamber which is
periodically compressed, if fitted with suitable one-way valves, is
a
compressor.
Next, consider the fact that feet tend to become hot.
So.
MaxCo Footwear, Inc., is proud to introduce its refrigerated
running
shoe*.
The shock-absorbing air chamber in the heel of this deluxe podial
accessory is equipped with the aforementioned one-way valves,
serving to pump a refrigerant around a cooling circuit with every
step. The hot side of the circuit is a loop close to the outer
surface
of the shoe, in the groove where the sole meets the upper. The
cold
side snakes back and forth beneath the insole, where it will chill
even the most fevered foot.
As a bonus**, the refrigerating power of the shoe increases with
the
level of exertion, elegantly matching the solution to the problem.
As a further bonus, a simple flip-switch on the side of the shoe
reverses the direction of the valves, enabling the shoe to actively
pump heat in and warm chilly feet on cold mornings.
* A second one, for the other foot, will be introduced shortly.
**Use of the word "bonus" is not meant to imply "free", and should
not
be so construed.
Lo-tech version
http://en.wikipedia...ki/Barefoot_running
[pocmloc, Jun 24 2010]
cool your shoes first ;)
http://www.rent-dir.../04/Picture-1_1.jpg
[xandram, Jun 24 2010]
Shoe Coolers
Shoe_20Coolers
Parallel thinking. [jurist, Jun 24 2010]
Liquid Cooled Shoes
liquid_20cooled_20shoes
More halfbaked thinking on the subject. [jurist, Jun 24 2010]
Air-Con Shoes
Air-con_20shoes
[jurist, Jun 24 2010]
Time Traveler's Handbook of 1001 Tense Formations
http://hitchhikers....01_Tense_Formations
Honestly, what will they might have taught them in the schools ? [8th of 7, Jun 28 2010]
Core cool - Refigerating gloves to improve athletic recovery.
http://corecool.co.uk/science.htm
Cools down core body temperature by taking advantage of the relatively high density of smaller blood vessels in the hand... [Jinbish, Jun 28 2010]
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"Well, he was jogging along, and I think maybe he trod on a bit of glass or a nail or something, and BOOOM !, that was it, up he went, just, like, gone, you know ? And then he came down just there ... and there ... and over there ... and in those two trees ... and here ... I couldn't believe it ... fashion victim, or what ?" |
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At least he didn't live to see the ozone hole widen. |
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So this operates on the same basis as the fire walker dictum: keep moving. |
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Have any of my R&D team been talking loosely??? We just
happen to be working on a rather ingenious pair of
vulcanologists boots based on this very principal. Careless
talk costs revenue. |
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The links are interiguing, but none of them uses the power
of walking to actively refrigerate the feet... |
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That's what happens in the Morgue, isn't it ? |
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//That's what happens in the Morgue, isn't it ?// I think you
may be thinking of Dunfermline. |
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That would be the place that very old humans go, to practice for being dead ? |
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I have no idea. I just took a wild guess that you were
thinking about Dunfermline. |
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Amazingly prescient, then. |
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We have departments for prescience, periscience and
postscience. We start the new recruits in postscience. |
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The hot parts of the loop could be fashioned into two little wings on each side of the shoes like the god Mercury has. |
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Yay! Or perhaps this could see a revival of the Ridiculously
Large Tongue phenomenon... Mr. Nike, Mr. Reebock, I am
ready to take your calls. |
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[+] This idea gets my bun since not only is it cool, but it's also the first idea to incorporate the refrigeration directly into the shoe. |
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Why not? You'll need some sort of strange flexible
probably carbon-based fiber material that is very low
density, super nonabsorbant to a chosen refrigerant,
doesn't change properties too drastically under various
temperatures and pressures for said fluid and is a good
conductor of heat. That is, the refrigerant stream must
all take place in a closed system without the use of
metals for tubing, which are presumably too heavy to
deal with inside a practical shoe, and this I predict will
be your main design problem. Still, when this hopefully
happens, it will be so damn cool! + |
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Well, you could probably use aluminium for the tubing, but
the flexing might fatigue it. Carbon fibre might be too
brittle. Plastic isn't a great conductor, but the only
requirement is to get all the possible heat into the
refrigerant inside the shoe, and dissipate all the possible
heat outside the shoe; a longish snake of moderately-
conductive material might do this. |
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Incidentally, I was trying to work out the power available
for cooling. Assume that the wearer is only walking. At
each footfall, 100kg (say) is brought to bear on the foot.
Suppose the compression chamber "gives" by 10mm as a
result (any more than this would, I think, feel odd). Then,
the total energy available per footfall is 100x G x 0.01 = 10
Joules. Assuming a normal walking pace (1 footfall per
second per foot) this amounts to 10 Watts of power per
shoe. |
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The average domestic fridge uses something like 100 Watts
(averaged over the day), so we have a 10th of a fridge on
each foot, which is promising. Of course, our system may
be less efficient than a domestic fridge, but we are still in
the right ballpark, playing ball with cool feets. |
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If the wearer is running, then the available energy will be
much more - not just because the footfalls are more rapid,
but because each footfall represents more energy (since
the wearer is "falling" onto the foot from some height,
rather than just transferring weight). |
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Of course, the shoe will also sap a certain amount of power
from the stride of the walker/runner, but this is a benefit
for exercisers. |
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// Carbon fibre might be too brittle // |
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It is, but diamond monofillament embedded in a carbon-silicon-halide copolymer is perfect. |
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Oh sorry, you don't know how to make that yet, do you ? |
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We will have been about to have known, as soon as
MaxTime's time machine will have been repaired. And surely
you will have meant "carbon-samarium-halide"? |
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gr. "you will have meant" |
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"you may have had to have meant to mean" (present semi-conditional plu-imperfect reflexive infinitive) |
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I was speaking resputefully. Do try and keep up. |
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Assuming this technology could also serve to dehumidify the shoe, I give it a [+]. It is miserably humid in the DC area right now. |
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Swimswim, dehumidifying instead of refrigerating should be fairly easy -- start with my Vacuum Membrane Dehumidifier [link] idea, but modify it so that the membrane is in the inner sole of the shoe (protected from damage by a piece of cloth or foam with good water wicking abilities) and the condenser is built into the outer sole of the shoe. Each step would simultaneously pump/compress steam from the membrane to the condenser, and pump condensate out a drain. |
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Why not blow the expanding air directly into the shoe? A refridgerator only cycles the air because it is refridgerant, not air. The shoe could take ambient air, compress it, and then inject into the shoe as it decompresses. |
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That's not a bad idea! OK, so we split the royalties. I'm
thinking 77:22.... |
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