Date:         Thu, 4 Jun 2009 13:23:44 -0700
Reply-To:     Keith Hughes <keithahughes@Q.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Keith Hughes <keithahughes@Q.COM>
Subject:      Re: Dometic Frig - Realistic Cooling
In-Reply-To:  <BAY0-PAMC1-F2zksp6J00008cef@bay0-pamc1-f2.bay0.hotmail.com>
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> From:    Deke Rivers <dekeriv@BELLSOUTH.NET>
> Subject: Dometic Frig - Realistic Cooling
>
> I have an '86 Westy with the original Dometic Frig.  It is cooling on either
> gas or 110AC - with maybe a slight advantage on the AC.  But it is just
> border-line on keeping the interior below 40 degf.  What should it be able
> to do?  Can it get below 40 degf if its 80 degf outside?  How about 90 degf?

On average, a well functioning unit should give you a 40-50°F
differential.  However, the differential is also proportional to the
ambient temperature.  The lower the temperature, the greater the
differential between the boiler temp and the condenser temp, and the
greater the efficiency.  Above about 110°F ambient, the efficiency drops
dramatically.  Once the ambient nears the boiler temp, the unit no
longer functions.  At 80°F ambient, my unit (with additional rear
condenser fan, and dual internal CPU fans) will reach a differential of
about 45°F.  At 115°F (in my garage) it drops to about 15-20°F differential.

Keith Hughes
'86 Westy Tiico (Marvin)