Possible Mod to AC System. Is it a good idea?

[David.Ullrich at ferguson.com]

RATS!!!!! Anybody know whether there is some way to mod the system to allow my idea to come to reality?

Dave

1987.5 Audi Coupe GT "Special Build" 2.3 - Anthracite Black
1998 VW Passat GLS 1.8T - For Sale CHEAP


-----Original Message-----
From: Ti Kan [mailto:ti at amb.org]
Sent: Thursday, April 25, 2002 2:03 PM
To: David Ullrich - 0018 HQ
Cc: quattro at audifans.com
Subject: Re: Possible Mod to AC System. Is it a good idea?


David.Ullrich at ferguson.com writes:
> On the 4000 & Coupe GT (possibly UrQ, but I don't know) when you flip the A=
> C switch to on, the system uses vacuum to close the fresh air flap, putting=
>  the system into recirculation mode. In theory this help get colder air bec=
> ause the already cooled air keeps getting recirculated through the system g=
> etting colder and drier with each pass. But on many days, the sun heats the=
>  interior to well above outside air temp, so in all reality this forced rec=
> irculation may delay the cooling affects because it has to catch up to the =
> outside temp. Right? So my thought on a mod would be to add some sort of re=
> circulation switch that would allow you to choose between recirculation and=
>  fresh/outside air when the AC system is on. From my train of thought it sh=
> ouldn't be hard to add. When the AC switch is flipped, it a vacuum actuated=
>  lever flips the flap closed. You could add a device that would block or ve=
> nt this vacuum when you want fresh air to go though the AC system rather th=
> an recirculated cabin air. So, what are your thoughts on this? Good idea? E=
> ven possible? Any thoughts on how?

The air duct design of the type 81/85 cars is such that if you
open the inlet flap (so that air is drawn from the outside rather than
through the recirc route), it doesn't pass through the evaporator and
therefore won't be cooled at all.  So on these cars it is impossible
to have non-recirc'ed A/C operation.

-Ti
01 S4 2.7 biturbo quattro
84 5000S 2.1 turbo
80 4000 2.0
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