Date:         Wed, 8 Feb 1995 10:03:04 -0800 (PST)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         David Schwarze <schwarze@superc.nosc.mil>
Subject:      Re: Gas Heater

Michael Heron writes:
> 
> you know those little square ceramic heater things (approx 8" * 8") that
> people put in their basements.... well, how difficult would it be to change
> them from 110 volts to 12 volts so they could be used in a car. I have one
> in the basement and it PUMPS out the heat. You could probably melt your
> floormats with such a device.
> 
> Is ther some sort of voltage inverter/modifier that you could put in your
> lighter socket to let such devices work. I know that they have such devices
> to allow you to use your portable radio in the car  (i.e runs a 110 volt
> appliance on 12 volt). What does everybody else think? Surely there must be
> some way to get heat in the bus without having to rely on that old rusted
> tube that runs the heat up from your engine to the cab.

[27 quoted lines deleted]

Michael,
	It is possible, yes, but not practical.  The reason is that heaters
draw too much power to be run on electricity in the car.  Example:  The
typical electric heater like the one you describe above (for the home)
draws about 1200 Watts.  At 110 Volts (in your house) that is about a 10
amp draw, which is reasonable, but at 12 Volts, the amperage jumps to 100,
and would probably be closer to 120 after 12-120 volt conversion losses.

120 amps would drain a typical car battery in 15 minutes or less.  It is
also more than double the output of the typical VW alternator.

This should also provide us with a gentle reminder of how inefficient our
engines are, when we see how much heat they put out.

-David

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David Schwarze                  '73 VW Safare Custom Camper (Da Boat)
SAIC Comsystems                 '73 Capri GT 2800 (Da Beast)
San Diego, California           '87 Mustang Lx 5.0 (Da Bruiser?  Soon...)
schwarze@nosc.mil                http://papaya.nosc.mil/~schwarze
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