Ventilation System Question

[Jeff.McMeekin@Corp.Sun.COM (Jeff McMeekin - WWFO Training)]

Why does Audi disable the air conditioning compressor when the
temperature drops below 40F? (I can't remember the exact temperature,
but it was around that number).  

I've got an A6 with climate control.  This weekend was our first
trip to the mountains for skiing and when the windows started to
fog up, I put on the defroster.  Instead of the cold air that quickly
clears the windows in moderate temperatures, the defroster spit
out a lot of warm air that quickly fogged up all the windows.  
They fogged up so quickly it was a driving hindrance.  For the next 45
minutes I tried all sorts of combinations of temperature settings
and blower settings and generally cursed the engineers at Audi
wondering if they had ever actually driven in any cold conditions.
In the end with the windows open the fogging was tolerably under
control, but certainly still present.

I got so ticked off I called the dealer to ask them but other than
arrange an appointment to have it looked at, they were no help.
Looking at the owners manual in more detail afterwards I came
across the line about the compressor being disabled below
a certain temperature.  That got me to thinking that the system
was working correctly but somehow I wasn't using it properly.
Then again it's one-button operation to turn on the defroster,
and the only thing I could vary if the default settings weren't
working would be the temperature and the fan speed.

I can't believe anyone who lives in a cold climate would put
up with this, so there must be a strategy to make the defroster
work better.  And I noticed the next day the defroster seemed
to work much better, so perhaps some of the problem related
to coming from the warm flatlands to the cold mountains.

As an aside, the following day it was snowing very heavily
as we left with 4-6 inches on the road and the kind
of crazy drivers among the skiers that make every ski trip
an adventure (you know, the kind that won't put on chains
until they encounter a hill where they finally lose all traction
causing them to drift into the oncoming traffic lane and stall.  And that's
where they decide to put on the chains).  Anyway like I said
the snow was really coming down heavily and the Audi wipers just
weren't up to the task, icing up so that I had to stop every 10-15 
minutes to clear them so that I could see.  Any suggestion
for dealing with that problem?

All in all I wasn't feeling too good about German engineering
after this trip.