If you started your journey in a relatively cool, dry environment, with a
low dry bulb temperature and a low wet bulb temperature, and the temperature
of your windshield stabilized at the dry bulb temperature, then drove into
an environment with a higher wet bulb temperature then the temperature that
your windshield had stabilized at (ie high humidity), then this phenomenon
will occur. The moisture in the air will condense out onto any surfaces
with temperature lower than the wet bulb temperature. This is the principal
of dehumidification - its how your air conditioner works in your home and
your car. I bet you noticed condensation on the car body, also.
-----Original Message-----
From: Malcolm Walker <walker05@camosun.bc.ca>
To: The Usual Suspects <triumphs@autox.team.net>
Date: Friday, August 06, 1999 12:13 AM
Subject: Strange weather phenomenon?
>
>While driving home tonight from a good game of badminton at the Y, had a
>strange thing happen- the windshield fogged up. Both sides, right across,
>to the point where I couldn't see through it! Luckily it's a small car
>and I am a tall guy- stuck my head out sideways (40 MPH sure gets fast)
>and drove on (much slower)
>
>I had just turned on the heater blower to warm up my hands a bit. I was
>also changing altitude. However, this hasn't happened to me before, in
>any of my other cars- although then again, I haven't had a convertible
>before!
>
>Then, as quickly as it had fogged up, it cleared. (The heater was still
>on). I didn't notice any fog outside the car, although we are
>experiencing some odd weather (thunderstorms, fog).
>
>Can anyone explain? No moisure appeared to have vented from the engine-
>the overflow tank was dry, no hoses split, engine looked fine (when I got
>home) Did I just release a long-incarcerated slice of Coventry from
>somewhere within the bowels of the car?
>
>-Malcolm
>* There is a FAQ for this list! Its new home is:
>http://www.islandnet.com/~walker05/triumph/trfaq.htm
|