Date:         Sat, 21 Jul 2007 16:16:34 -0700
Reply-To:     Michael Elliott <camping.elliott@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Michael Elliott <camping.elliott@GMAIL.COM>
Subject:      Re: Where is The Heat Going?
Comments: To: Mike S <mikes@flatsurface.com>
In-Reply-To:  <20070721225600.115881165C3@hamburg.alientech.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Actually, no -- a fair question. It was just an off-the-cuff statement.
But a real strong indication of heat generated is power consumption. On
12V, the Dometic draws -- what? 8 amps continuously? While the Norcold
pulls 2.5A (measured) when running, and has a duty cycle less than 50%
in my experience. So on 12V, the Dometic is a nice little 8 x 12 = 96
watt heater, while the Norcold is closer to 2.5 x .5 x 12 = 15 watts (or
less depending on ambient temp and thus duty cycle). So the Dometic
dissipates more than 6 times the heat as the Norcold.

I betcha that when the Dometic is running on propane, there is even more
heat dissipated due to the hot flue.

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR



Mike S typed:
> At 06:02 PM 7/21/2007, Michael Elliott wrote...
>>  Far less heat
>> than what the Dometic has to dump: heater + extracted food heat.
>
> I'm not so sure that's true. You are definitely neglecting the heat
> given off by the motor and (friction in the) compressor. Do you have a
> citation stating efficiencies of both ammonia and Rankine cycle
> refrigerators at this scale?
>