Re: how do you make the a/c colder?

["Fred Munro" <munrof@isys.ca>]

-----Original Message-----
From: LOACESQ@aol.com <LOACESQ@aol.com>
To: quattro@coimbra.ans.net <quattro@coimbra.ans.net>
Date: Wednesday, June 03, 1998 9:41 AM
Subject: how do you make the a/c colder?


>Hi List,
>
>I just had the a/c changed over to 134a and it's not very cold even running
at
>the LO setting for about 45 minutes.  At best,  I's say it had a moderate
>cooling effect.  The system was pressure tested and tested with a
refrigerant
>detector for leaks--none were found.  The compressor is running fine.  Is
>there anything that can be done to get the a/c colder?
>
>TIA!
>
>adam


Hi Adam;

    You lose 20% of the cooling capacity when you change from R-12 to
R-134a. In addition, the pressure generated by the R-12 compressor is not
high enough to take full advantage of the R-134a characteristics.
    BTW, R-134a is a mixture of propane and isobutane. Something to keep in
mind in a front end collision with that condensor hanging out in front. The
automotive engineers apparently believe the risk is acceptable, but I would
think there is a good chance of a fireball with a couple of pounds of
barbecue fuel spewing out of a ruptured condensor.
    I don't know of a way to make the system run colder if it is properly
charged and the propane/isobutane mixture is right. One of the problems with
R-134a is that the isobutane is lost preferentially and the mixture gets out
of proportion, resulting in loss of cooling capacity. This apparently takes
3-4 years and the system has to be drained and re-charged. Fortunately,
R-134a is cheap.

HTH

Fred Munro
'91 200q  253k km