Date: Sun, 1 Jul 2007 08:22:59 -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: Free battery and Fridge For Sale
In-Reply-To: <4686ECD0.2010401@colorado.edu>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Richard, almost exactly one year ago I ran a similar series of tests
on my Dometic, using household current. I measured its inside temp vs
outside temp (90F midday), with and without 8 cans of soft drink* inside
to provide "thermal mass", sitting in the open vs in a box to mimic the
Westy cabinet, and with or without a good quality fan blowing on the
rear radiator bits.
Under my test conditions, the fan added maybe 4 degrees F of additional
cooling whether the reefer was empty or not. Having the soft drinks in
the reefer slowed the inside temperature rise, as your test showed.
The best results obtained were with the fan and with the soft drinks.
Under these conditions, the reefer was pulling a 52F temperature
differential at the end of the day.
I have a pdf of the test results, including swell graphs of inside vs
outside temps w/ differentials for the various conditions. P-mail me if
you want a copy.
Looking at the test results now, one year later, I have to say that the
Dometic actually performed quite well. At no time did the inside temp
exceed 45F. I still have that Dometic and I'm now tempted to pull it
back out of wherever the heck I have it stashed and do some more testing
on propane. Have to wait for things to hot up, though. Our local
traditional Santa Ana winds in September should do it.*
* Beer results probably not much different unless these is a significant
difference between how many cold ones of either beverage are pulled out
and replaced with warm ones on a hot day.
** We have three seasons in coastal Southern California: mudslide
season, wildfire season (comes with Santa Ana winds), and earthquake
season.
--
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
Richard A Jones typed:
>> I have come to the conclusion that it is best to become our own expert on
>> how to make your old Dometic perform at its best with good maintenance and a
>> few enhancements mentioned in the archieves of this list.
>
> I have been running my Dometic ('87 Syncro Westy) for about ten
> days now as a test. Worst case--in the sense the van is parked
> with the driver side to the west--full Colorado sun in the afternoon.
> It has windows slightly open--more like "locked up, hiking" than
> "wide open, drinking beer." Boulder temp is 92 degrees now at
> 5 pm, 6/30/07.
>
> It is running on 115V, with a Fridgemate fan inside. Thermostat
> set to about 11 o'clock. Thermometer on the floor of the fridge.
>
> Empty fridge: about 28 degrees in the fridge in the morning, with
> the interior of the van below 65 degrees. When the interior of
> the van heats up to 115 or above about 5pm, the inside of the fridge
> will go up above 45 degrees.
>
> Better fridge: 4 1-liter bottles of water in the fridge to add
> thermal mass. Inside fridge temp 32 degrees in the morning and
> 41 degrees in the afternoon. This performance satisfies me.
> Proves that more beer is better....
>
> How would it perform on propane? I may switch in another day and
> see, but why should it not be the same? That is, why would a
> Dometic engineer not design the three ways to be equivalent? Would
> be easy to pick orifice size, heater wattage, etc, to match, no?
> The 12V heater is 7A = 84 watts; I think the 115V heater is 85 watts.
> Anyway, if propane performance is much different from 115V, there
> is probably a problem with the orifice or pressure or the flue.
>
> There were millions of Servel gas fridges used in the 50s and 60s.
> And today--the Servel name is owned by Dometic and they still make
> gas--and kerosene!--fridges. Today there are millions of RVs
> with gas fridges--with freezers.
>
> I think our Westy problems are the small size of the fridge--my
> test above demonstrates that thermal mass gets you through the
> hot afternoon--and the smaller size of the Vanagon. I have seen
> 121 degrees inside--not air temp, but the temp of the interior--
> cabinets, etc. To have 41 degree beer with a temp differential
> of 80 degrees to the outside--is pretty amazing. Just remember--
> every beer you drink means decreasing thermal mass in the fridge--
> and so the next one will be slightly warmer. ;-)
>
> Richard
> Boulder
>
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