Date: Wed, 31 Aug 1994 09:41:50 -0700 (PDT)
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: David Garth <dgarth@cymbal.aix.calpoly.edu>
Subject: hot water and shower at last!
I've been experimenting for a few months with different hot water schemes
for my Westy. I finally have developed one which is safe and efficient,
and I thought I would share it in case anyone is interested.
I had already replaced the oem water pump with an RV type pressure
sensitive demand type. These pumps are only about $50, and are easy to
install in the compartment above the tank. New pressure water line needs
to be run to the compartment under the sink, and then teed into the
pressure line (grey) which goes up to the faucet. (Water will leak out of
the old non-pressure unneeded line unless you cap it.)
My previous experiments had convinced me that it was too difficult and
dangerous to run the coolant lines through the water tank. So instead I
built a small 8" water to water heat exchanger. It's just two tight flat
coils of 3/8 copper tubbing soldered together. Coolant flows through one
loop, water from the tank in the other loop. I located the heat exchanger
right behind the rear heater, so it was easy to tee from the heater hoses.
The trick is controlling the heat...and I'm quite proud of my solution.
For $10 I was able to get a new water bed heater control unit. This is a
mechanical one, not solid state. It was built to switch 110v, but it
works just great on 12v if you just use it as a switch. The temperature
probe goes inside the tank at the bottom. I set it to 100 degrees.
A small selenoid sprinkler control valve is connected to the water bed
controller. When I turn on a "water heater" switch, 12v from the ignition
switch goes to the valve, opens it. This turns on the pump, which pumps
water through the heat exchanger, and back to the tank. When the water
get to 100 degrees, the valve closes, and the pump shuts off. The water
stays at exactly 100 degrees as long as the engine is running. It stays
warm for many hours after shutdown.
I have also installed a hand shower in the little space at the rear
opening to the left of the A/C blower. 13 gallons of hot water is plenty!
--Dave Garth
San Luis Obispo