-----Original Message-----
From Ron Soave <soavero at yahoo.com>
To: Wiedemeyer <boxweed@thebest.net>
Date: Monday, January 17, 2000 5:19 AM
Subject: Re: cool ... no lbc
>> Only if the temperature is cooler than 110 inside
>> the car and there's an
>> equivalent amount of breeze inside the car.
>
>Huh? Yes, Bob, heat transfers from hot to cold, no
>delta t, no heat transfer (unless it is latent). 110
>air hitting 98.6 skin warms it up, Bob. You remember
>Massflow*Cp*delta T?
>
>=====
>Ron Soave
>
Except for one "minor" little detail, Ron.....We have these wonderful little
things called sweat glands that, when we are too warm, expel water onto the
surface of our skin. Evaporating this water from the skin requires an
enormous amount of energy, which is "sucked" from our bodies in the form of
heat. The overall result is a cooling down of our bodies, even if the
ambient temp is greater than our body temp. The breeze simply helps move
the evaporated water away from the surface of the body so that more
evaporating sweat from the body can take its place faster. So, if you're
sitting inside the car, and it's around 100 degrees with the windows up (no
breeze), and it's 110 degrees outside, your body will actually be cooler if
you roll down the windows and let the 110 degree breeze hit you (Even
though the hot breeze will make you "think" that you are hotter, your body
temp will actually be lower). If you are sitting in the hot car with the
windows up and no breeze, you still sweat, but instead of the sweat
evaporating and cooling the body, it just accummulates on the surface of the
body and runs down your face, arms, etc., and becomes an inefficient cooling
method.
Bob
|