Date: Sun, 22 Jul 2007 12:08:26 -0700
Reply-To: Mark Drillock <drillock@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark Drillock <drillock@EARTHLINK.NET>
Subject: Re: Where is The Heat Going?
In-Reply-To: <46A3A77B.7080404@gmail.com>
Content-Type: text/plain; charset=us-ascii; format=flowed
Since I have camped many times where the day time temps exceeded 100
degrees in the shade outside the van, I am certain that the temps behind
the fridge must have been at least that hot many times and yet my fridge
still cooled.
Mark
RM182A with external exhaust vent behind fridge, fan
Michael Elliott wrote:
>
>
> That would be the link that Chris C provided
> ( http://www.bdub.net/manuals/DometicBulletin12-87.pdf ) which says that
> if the air temp in the van (presumably what they mean is the temp behind
> the refrigerator where the cooling unit lives) exceeds 100 (F) then the
> "cooling process will slow down or stop completely."
>
> In other words, the Dometic 182 can hold the 40 to 45 degree temperature
> differential* that I and others have measured as long as the air temp
> around the cooling unit is below 100F. After that, the refrigeration
> simply stops.
>
> Later in the bulletin, they write that if the refrigerator does not pass
> testing if the air temp is above 90F, it "may indicate a restricted
> air flow [behind the refrigerator]." So 90F rather then 100F is when the
> cooling unit is feeling the heat.
>
> So my guess (and I wish I had an industrial oven to place the unit into)
> is that when the rear temp is less than 90F, the Dometic can hold its
> internal temp 40-45F less. Between 90 and 100F, the differential gets
> smaller as the cooling unit begins to lose efficiency. Once above 100F,
> the cooling unit no longer cools at all.
>
> Those of you who like to make measurements and have Dometics, how about
> sticking a thermal sensor behind the refrigerator and one in the van and
> reporting how the temp (gas vs electric, what the heck) back there
> compares with the ambient temp?
>
> -------
>
> * As Dennis says, these are old refrigerators. Some of us may have
> "weak" ones, some may have "strong" ones. If you're scratching your head
> wondering what the fuss is about because your food and beverages are
> always nice and cold, you may have a "strong" one. Or maybe you camp in
> cooler environments, or have a more generous assessment of what is
> sufficiently cold. Hard to say unless you can do as Jake suggested:
> measure your van's internal temp and the temp inside the reefer on a hot
> day. If it's running 70F outside and you have 30F inside the reefer,
> then no big deal, this is well within the operating characteristics of
> the refrigerator. On the other hand, if it climbs above 90F at noon and
> stays there until evening, yet the refrigerator's temp stays more than
> 45F below the temp in the van (or, better yet, near the cooling unit),
> then you might have a "strong" unit.
>
> --
> 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
>
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