Date: Sun, 25 Sep 2011 10:03:04 -0700
Reply-To: neil n <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil n <musomuso@GMAIL.COM>
Subject: Re: insulating hot side of Dometic refer
In-Reply-To: <897B1CED-42CC-437E-9D28-8247580E1CCF@shaw.ca>
Content-Type: text/plain; charset=ISO-8859-1
I followed other peoples leads by:
- installing a city water fan
- improving insulation behind fridge and making a channel to improve
air flow (first and second pic starting here:):
https://picasaweb.google.com/musomuso/DometicPics#5508482295562306834
I think this helps to make city water and stock Dometic fan a bit more
efficient in pulling cooler air from floor area of van up and past
rear of fridge and of course, pulling hotter air away from rear of
fridge.
Caveat to the "channel": I leave the city water fan on almost all the
time in hot weather as the "channel" may be a double edged sword; it
allows fan to pull air mostly from channel area, and not surrounding
areas, but also may not allow as much natural air movement
(convection) and/or may contain air warmed by fridge and sun hitting
side of van.
Phil Zimmerman pointed me toward insulating the exhaust tube. Maybe
that race car exhaust insulating tape would work? Be careful what you
use. Roger Sisler commented (archives) that using non stock fiberglass
insulation here:
https://picasaweb.google.com/musomuso/DometicPics#5308396270878924818
caused a bad smell when fridge running. Maybe exhaust tape would smell?
Taking Alistairs cue I re did the insulation behind the fridge. Not
that scientific, but pointing my IR gun at bare panel and insulated
yielded quite a difference in temps
https://picasaweb.google.com/musomuso/DometicPics#5364783078257333666
I redid that particular insulation with blue rigid foam.
Neil.
On Sun, Sep 25, 2011 at 9:01 AM, Alistair Bell <albell@shaw.ca> wrote:
> Neil has done some work on the insulating topic, and so have I. I tried installing some sheet metal behind the fins, to make a more efficient chimney for the warm air to rise up. But it was a pain to get the metal lying just right, there is less room back there than you think when the fridge is out, especially if you add some insulation to the metal (as I did).
>
> Neil insulated the exhaust pipe I think.
>
> I was less than overwhelmed with the result. But the city water mod really does work. I recommend that, as well as insulating the body panel of the van adjacent (to reduce heat gain from the sun shining on the side of the van). I had a fan on the side vent that you mention putting in a 12 V outlet. When on, it really did push hot air out. But that was not as efficient (doh) as pushing the hot air out of the van via the city water mod.
>
>
> alistair
>
>
>
>
> On 2011-09-25, at 8:28 AM, Edward Maglott wrote:
>
>> It's time for the periodic fridge removal and as usual I'm wondering
>> what could be done to improve it's hot weather performance. Mine
>> seems to work best on electric in hot weather. I theorize that the
>> propane fire puts a lot of extra heat back there, making it harder
>> for the refrigeration process to expel heat. So maybe making sure
>> more of that heat stays away from the fins would help. And also
>> keeping more heat away from the refrigerated box seems like a good
>> idea. Would it help to put some thin insulation like reflectix
>> between the heat radiating fins and the back of the unit? It seems
>> to be made as one unit with the fins attached to the back in several
>> places, so doing this would require a number of separate pieces but
>> not too hard. How about adding insulation around the "hot column"
>> and on the exposed exhaust pipe as it goes up from the column to the
>> exit outside? That is just bare metal throwing off heat behind the
>> cabinet. Any ideas or comments?
>>
>> While I'm in there I'm prepping for the classic exhaust fan in the
>> former city water inlet door which should help, and putting in a 12V
>> accessory outlet next to the vent grille on the back of the fridge
>> cabinet. What is the best choice these days for a heat transfer
>> compound to put between the cold-pipe and aluminum fins inside the fridge?
>>
>> Edward
>
--
Neil n
65 kb image Myford Ready For Assembly http://tinyurl.com/64sx4rp
'81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/
Vanagon VAG Gas I4/VR Swap Google Group:
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines