[s-cars] Climate Control - Damn the Snowflake

[manuelsanchez at starpower.net]

I may have things confused, I'll check later, but what I seem to remember was ice on a radiator like element. This was a few years ago though, before the problem of the compressor turning on and off by itself, so my memory could be faulty.

Once I get the bentley liscense transferred to the new computer I'll have a look see at the pieces/parts and their proper names/locations.

Thanks.

-m



---- Original message ----
>Date: Wed, 20 Jun 2007 23:10:16 -0400
>From: djdawson2 at aol.com  
>Subject: Re: [s-cars] Climate Control - Damn the Snowflake  
>To: munrof at sympatico.ca, manuelsanchez at starpower.net, rit_bellis at hotmail.com, s-car-list at audifans.com
>
>   I'd have to guess that he's mixing up his terms. 
>   Ice can form on the evaporator as a result of a
>   failed temperature probe... not uncommon.  The
>   probe is supposed to stop icing by deactivating the
>   clutch on the compressor.
>
>   -----Original Message-----
>   From: Fred Munro <munrof at sympatico.ca>
>   To: manuelsanchez at starpower.net; djdawson2 at aol.com;
>   rit_bellis at hotmail.com; s-car-list at audifans.com
>   Sent: Wed, 20 Jun 2007 9:00 pm
>   Subject: RE: [s-cars] Climate Control - Damn the
>   Snowflake
>
> Hmm, ice on the condenser is bad, Manny. The condenser is supposed to be
> hot. The compressor takes cooled refrigerant gas from the condenser and
> compresses it to liquid under pressure. The high pressure liquid passes
> through an orifice at the evaporator and turns back to gas in the low
> pressure zone in the evaporator, absorbing heat as it changes state from
> liquid to gas. The hot low pressure gas then goes to the condenser where it
> releases heat to the airflow and goes back to the compressor.
>
> If you are getting ice on the condenser, that would tell me you have a
> restriction in the condenser that is acting as an orifice and allowing the
> refrigerant to pass from a high to low pressure zone in the condenser,
> absorbing enough heat to freeze moisture. A low refrigerant charge can
> freeze up the evaporator because the pressure drop across the orifice is too
> high and too much heat is absorbed ( the low pressure side pressure is too
> low). A high refrigerant charge usually means the low side pressure is too
> high and the cooling effect is impaired (the pressure drop across the
> orifice is not high enough). I suppose a too high charge could result in
> high pressure gas entering the condenser and may make it prone to freezing
> if there is a restriction there. I'm just speculating here, never had this
> problem.
>
> Fred
>
> -----Original Message-----
> From: s-car-list-bounces at audifans.com
> [mailto:s-car-list-bounces at audifans.com]On Behalf Of
> manuelsanchez at starpower.net
> Sent: June 20, 2007 9:21 PM
> To: djdawson2 at aol.com; rit_bellis at hotmail.com; s-car-list at audifans.com
> Subject: Re: [s-cars] Climate Control - Damn the Snowflake
>
>
> What if I were to tell you that I noticed once after a loooong summer
> highway run in moderate temps (mid 80's), say about 5 hours of constant
> running, I found Ice on the condensor?
>
> -manny
>
> ---- Original message ----
> >Date: Wed, 20 Jun 2007 17:27:11 -0400
> >From: djdawson2 at aol.com
> >Subject: Re: [s-cars] Climate Control - Damn the Snowflake
> >To: rit_bellis at hotmail.com, manuelsanchez at starpower.net,
> s-car-list at audifans.com
> >
> >   Again... higher temps equal higher pressures.  If
> >   your A/C is cutting out only at higher outside
> >   temps, my bet is that you're not pushing enough air
> >   accross the condensor.  This could be for several
> >   reasons... fan clutch... electric fan... or a
> >   condensor plugged with debris.
> >
> >   -----Original Message-----
> >   From: Rit Bellis <rit_bellis at hotmail.com>
> >   To: djdawson2 at aol.com; manuelsanchez at starpower.net;
> >   s-car-list at audifans.com
> >   Sent: Wed, 20 Jun 2007 2:19 pm
> >   Subject: RE: [s-cars] Climate Control - Damn the
> >   Snowflake
> >
> > I too am interested in the answer to the snowflake question.  My 93 s4
> quit
> > cooling when it hit 84 degrees or higher all last summer. Then, the car
> > self-healed over the winter.  (only change being a missing belly pan.)
> this
> > summer (audi gods and thor permitting) the snowfake has kept right on
> > working as the temps hit 95 degrees and higher.  I have long suspected the
> > uper limit temp sensor, but is there another possible culprit?  Thanks!
> >
> > -----Original Message-----
> > From: s-car-list-bounces at audifans.com
> > [mailto:s-car-list-bounces at audifans.com] On Behalf Of djdawson2 at aol.com
> > Sent: Wednesday, June 20, 2007 12:59 PM
> > To: manuelsanchez at starpower.net; s-car-list at audifans.com
> > Subject: Re: [s-cars] Climate Control - Damn the Snowflake
> >
> >
> > High pressure, low pressure, and freezing are three I know off the top of
> my
> > head.  If the A/C works fine under less than extreme conditions, I would
> > wonder if high pressure is the problem.  I would then look into the fan
> > clutch and electric fan operation... these are what keep high pressures
> from
> > developing.
> >
> >
> > -----Original Message-----
> > From: manuelsanchez at starpower.net
> > To: s-car-list at audifans.com
> > Sent: Wed, 20 Jun 2007 12:47 pm
> > Subject: [s-cars] Climate Control - Damn the Snowflake
> >
> >
> >
> > Fellow S-heads,
> > All this climate control talk has prompted me to ask the following: What
> > causes the Snowflake to turn off by itself: 1. Low Refrigerant (some fail
> > safe mode to spare the compressor some unsightly
> > eath)
> > 2. Failing Climate Control Head
> > 3. Other
> > She tho must be obeyed is annoyed with me, as my car seems to suffer from
> > the
> > nowflake and compressor shutting off when it's Africa hot outside. I, and
> > wifey, thank you. -Manny 5.5 UrS6 Avant (Flakey Snowflake)
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