h a l f b a k e r yMake mine a double.
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Sweating Jacket
Being hot isn't fun, neither is being burned. Solve with evaporation! | |
This morning I didn't ride to work on a motorcycle. There
are many reasons, but cold is the main one. It's one thing
standing about in cold temperatures and quite another
sitting quite still holding your hands out in front of you
while enduring a 70mph induced -25C wind chill. Now,
there are
expensive heated solutions to this.
They take ages to get into and out of, and largely aren't
worth it. Sticking to warmer months is the clever way to
go.
In warmer weather, you can slip on some expensive
leather
safety gear secure in the knowledge that adjusting a zip
or
two will change the airflow enough to maintain a
tolerable
temperature. Until it starts getting really hot. It comes
as
a surprise, but when the temperature hits 37C, instead
of
wind chill, wind heating occurs. At 42C, you're genuinely
baking. The solution is simple: remove the jacket, ride in
a
t-shirt and let your inbuilt evaporative cooling take care
of
the problem. Except when you fall off and are subject to
robust exfoliation.
So, leather is available in many types and treatments,
some that take up water. Take a motorcycle jacket and
create a waterproof panel in the back, atop this place
the
absorbent leather panel then use a small peristaltic or
diaphragm pump to force water between them. The
water
will absorb into the leather and then evaporate from the
surface taking significant heat. The rider can control the
flow to modulate cooling.
This might also be useful in firefighting/mining/industrial
environments.
xkcd: Jacket
https://xkcd.com/90/
for [IT] [notexactly, Dec 07 2018]
[link]
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Surely the solution is simply to wear a nice car? |
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This idea is not without merit. However ... |
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On the interior of the garment, run a mesh of thin-walled capillary pipes, filled with water. This is a closed system; the water is circulated by a small pump.
On the back of the garment, have a small backpack, with two inlet scoops positioned over the wearer's shoulders, with a vent at the lower rear. This is the open-circuit part of the system. Water from a small tank is sprayed onto a mat of synthetic fibre through which the piping from the closed-circuit capillaries runs.
The forward motion of the rider pushes ambient air of low humidity into the scoops, where it flows over the saturated mat. Evaporative cooling draws heat from the system and the cooled water passes back into the suit; warmer, moist air is exhausted from the rear vent.
Additional side-tubes with venturii nozzles could be positioned at the sides to increase airflow. |
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//This is a closed system; the water is circulated by a small
pump.// |
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If you're going to do that, why not just run a
Peltier/heatsink and plug it into the bike? |
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Why not, indeed ? Then the system can be configured for either heating or cooling as required. |
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The liquid should be viscous and red, for effect in minor
crashes. |
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With suitable employment of large-bore needles, the unit could be configured to cool the wearer's blood directly, thus removing the need for an additional reservoir. |
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But a single leak and you have compromised a
critical system. Why not take advantage of the
blood-air exchanger in the chest or the blood-liquid
exchanger in the colon(or gills if you're a fish)? |
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