On Tue, 15 Nov 2005 11:51:45 GMT, "Ross Cranford"
<rossc96@hotmail.com> wrote:

>That and the fact the reason they say to run the A/C to clear the windows is
>that it acts like a dehumidifier and helps remove moisture from the air.

Yeah. So in the summer time, the evaporator runs at around 32F/0C, the
water vapor in the air condenses on the evaporator coils, forms
liquid, and drips out of the car.

But in the winter when it is say 0F/-18C, the water vapor turns to
frost on the evaporator coils. It can't drip out because it is solid
ice. The evaporator ices up. At least this will be true when the car
is first started if the A/C is on.

Ten or 15 minutes later when the interior warms up, the situation may
be different, but by then you won't need the A/C to dry the air,
because the dry air from the outside plus the heat is doing that.

Just trying to understand what is happening....