Re: automatic climate control

["Graydon D. Stuckey" <graydon@apollo.kettering.edu>]

On Thu, 10 Sep 1998, Stefan Richter wrote:

> It has gotten rather cool here in Buckingham Pennsylvania over the past 4
> or 5 days.  My 95 S6 seems to love the temperature and air quality, it is

My 5KCSTQ loves it too.  :-)

> running better than ever.  Perhaps some of you can enlighten me on the
> climate control system a little.  When I press the AUTO button, no matter
> what the outside temperature, (52 F this morning), and no matter what I set
> the temperature on the system, the a/c symbol lights up, and you can hear a
> relay clicking in the dash, presumably to turn on the a/c on.  I am a

Makes sense.

> little surprised that the system is not sophisticated enough to recognize
> when a/c is not needed, hence automatic climate control.  Is there a
> problem with my system or is this simply something I should get used to? 

I don't know how the engineers calibrated the AC to run on the S6, but I 
know that it is normal for the compressor to engage at any temperature 
above 45 deg F roughly.  Rememeber, the AC system is used for humidity 
control as much as temperature control.   This is very important to 
maintain a clear windshield.  I like the AC on even early in the spring, 
because I get stuffed up if it gets too humid in th ecar.  My wife thinks 
I'm nuts and she cranks up the seat heater. :-)

Most modern HVAC systems are calibrated assuming a set-temperature of 75 
deg.  Therefore, the vast majority of individuals will find themselves 
most comfortable with an automatic HVAC system set to 75-Auto.  You 
might find you need to rais or lower the set-temp slightly, but you'll 
probably get the most satisfaction with the system on "Auto" most of the 
time.  My experience in the '86 5KCSTQ is exactly that - I'm most 
comfortable at 75-Auto, as long as it is workjing as designed.  Now 
Brendan's A4 seems a little hot.  He likes it at about 63 I think, while 
I had it turned down to about 70.  I think Audi should do a little more 
work on their calibrations on that car.

Later,
Graydon D. Stuckey