Thanks very much! This is very helpful to me - I am going to see if I can
get something like this setup in my van too.

Imitation IS the greatest form of flattery - thanks again!

Marshall Ruskin,
----- Original Message -----
From: "Ed McLean" <email99@bellsouth.net>
To: "Marshall Ruskin" <mjruskin@HOME.COM>; "Vanagon List"
<vanagon@gerry.vanagon.com>
Sent: Tuesday, November 13, 2001 10:05 PM
Subject: Dual Air Conditioning in a Vanagon

> Marshal Ruskin asked:
> >  Please tell me more about the second evaporator you installed,
>
> OK, here are the basics of the two air conditioning system for the
> Vanagon.
>
> I used an evaporator from Cooler Air Products ((972)-771-3791, Rockwall,
> Texas).  This is essentially a Behr after market unit that mounts behind
> the dash above the glove box.  It uses the original fresh air vents on
> the sides of the dash as well as two new vent coming out of the old ash
> tray opening.  The refrigerant lines were plumbed in parallel.  I
> modified the controls from what Cooler Air suggested.  The thermostat
> for the front unit controls the compressor magnetic clutch and the rear
> unit thermostat controls a solenoid valve in the refrigerant line to the
> rear (original) unit.  There is an over pressure switch to protect the
> system from excessive refrigerant heat/pressure.  Both evaporators have
> R134a expansion valves.  The system was converted to R134a (~50 oz) and
> the compressor is a Sanden SD709.  I am using the original VW
> condenser.  The controls are mounted on the dash to the left of the
> steering column and are essentially a double set of the standard VW
> Westy AC thermostat/fan switch unit.  To run the thing you simply turn
> on the front air conditioning and set the fan speed and temperature.  If
> you want the rear unit on you turn on the rear fan switch and adjust the
> rear thermostat for the temperature in the rear.  There are two LED's
> (green) to indicate when the thermostats are calling for cooling so I
> can make small adjustments in the temperature when my family screams
> "It's too cold back here!", and a third LED (red) to indicate when the
> overpressure switch shuts off the compressor.  Generally I run both fans
> on low and cooling is adequate except when the outside temperature is
> above 100 deg F or we are stopped in traffic.  The system has been
> reasonably problem free but I would like to have more condenser capacity
> so the refrigerant pressures would be lower and cooling would be better
> in while stopped and in slow city driving.  When driving I usually get
> temperatures of 40 degrees F and 48 degrees F with one and both
> evaporators running, respectively.  The 40 degrees is limited by the
> thermostat and not the cooling capacity.  When both systems have their
> fans running on high there is a tremendous amount of air moving in the
> bus.  Temperatures are higher without a generous flow of air through the
> condenser.  I've been thinking of adding an additional, fan cooled
> condenser under the floor or above the axles.  This would be plumbed in
> series with the original condenser.
>
> The system works well.  The nicest thing about it is that it provides
> great cooling in the front footwells.
>
> Any other questions?
>