Jim Brewer wrote:

Paul,
I just got a Northern catalog and they had serveral ceramic heaters that run
on 12 volts.  One cost $20.00 and was advertised to keep your feet warm or
defrost your windshield. It had a cigarette plug but could be hard wired for
greater safety.  Seems like a simple solution for heat.  I think it weighed
2 lbs.  No plumbing.  Has anyone thought of using this? Cons?

Paul Lamar responded:

500 watts 42 amps at 12 volts.

Not through a cigarette lighter you ain't. :-)

I imagine that the Northern heater is a 300 watt unit.  I cannot imagine that the
cigarette lighter circuit in most cars is fused at more than 20 or 25 amps.  Since
I *assume* that the Northern folks use the alternator charging voltage instead of
the battery voltage (to get the numbers higher for the catalog), that makes a
maximum power available of 25 amps * 13.5 volts =  338 watts.

Then I got smart and went to the Northern online catalog for the *real* numbers.
:-)  Is this the heater you are talking about, Jim?
http://www.northerntool.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=23041&prmenbr=6970

200 watts; not exactly a roaring fire.  Keep in mind that a good hair dryer is
1500 to 1800 watts today.

These two 300 watt heaters look like a better option (50% more heat, and still
electric):
http://www.northerntool.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=21030&prmenbr=6970

http://www.northerntool.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=43441&prmenbr=6970

Of course, the best option seems to be this little 3.9 amp (53 watts)  job:
http://www.northerntool.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=21785&prmenbr=6970

(but then you're back to plumbing coolant to it).

Russell Kent

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