Date: Sun, 22 Aug 2010 14:13:35 -0700
Reply-To: neil n <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil n <musomuso@GMAIL.COM>
Subject: Re: How Hot Behind Dometic Fridge On 100+F Day? (insulation
clearances)
In-Reply-To: <4c719030.6682e50a.378d.ffffaf13@mx.google.com>
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On 8/22/10, David Beierl <dbeierl@attglobal.net> wrote:
> At 02:38 PM 8/22/2010, neil n wrote:
>>http://tinyurl.com/28ct5ew But.... my guess is that the bubble wrap
>
>
> Ouch. I didn't realize how low that external fan is. Forget what I
> said about closing off the top vent, you'll need to be drawing air in
> there to allow cooling of the upper fins. Side vent wants testing
> but I suspect closing it would be good idea. It may also be
> necessary to restrict the bottom intake to get adequate flow past the
> upper cooling fins.
Didn't see your comment on closting top vent. It's always remained open.
The idea, currently, is to leave the lower stock grille open (stock
fan is switched. I generally leave it, and City Water fan on all the
time in hot weather), pull air in/up, then out the City Water fan. I
had wondered about where this fan was pulling air from. To that end,
had thought to direct it's intake better with some shrouding material
so it was pulling air more from rear of fridge and not surrounding
area. As is, it likely pulls air from all around it. Regardless, on
hot days, it blows out hot air.
> Reversing the fan to blow into the cavity instead of out might work
> better. I presume there's a weather shield of some sort over the
> fan? If not you're guaranteed water in the cavity whichever way the fan
> blows.
Fan has a hood on exterior. Needs a grill and/or sprung flap to keep
vermin/bugs out. No issues with bugs et al yet though and hood should
keep most or all water out.
> Also, has the effect from the ventilation system in the moving
> vehicle been tested?
No. Had wondered about that. (fan on or not, vent open or not)
> Incidentally, back when I was playing with mine I put in a fan to
> extract air from the upper vent or blow it in at the bottom and to my
> surprise fridge performance dropped noticeably. I forget the
> numbers, but it was significant. OTOH replacing the OEM rear fan
> with the larger Fridge-Mate one and adding some quarter-inch
> foil-sided vinyl siding backing improved things noticeably without
> adding any noise or increased current draw (60 ma or so).
I recal Richards musings about 2 muffin fans at rear bottom. He
suspected that 2 blocked some of the convection air flow. Would a fan
up top have done something similar? (even when running?)
Roger Sisler has pics of a Dometic he worked on. One shows insulation
on the back. Did you insulate the back of fridge itself?
Neil.
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"
http://tubaneil.googlepages.com/
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
