Date: Tue, 13 Nov 2001 23:05:32 -0500
Reply-To: Ed McLean <email99@BELLSOUTH.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Ed McLean <email99@BELLSOUTH.NET>
Subject: Dual Air Conditioning in a Vanagon
Content-Type: text/plain; charset=us-ascii
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?
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