Refrigerator cooling fans

[Chuck Wheeler]

You are right Hank, We were in Gila Bend, 109 degrees and the Dometic held 37 in the refrigerator and -5 in the freezer. I was told by a service tech that a fan could help cool down faster but if the box was not getting cold enough there are other problems. He also said that if should be placed to remove hot air from the compartment behind the refrigerator not to blow on the coils because you could just recirculate hot air. He placed our fanat the vent stack.

- Chuck Wheeler-

FC 31SB Fort Worth TX

---

From: WanderlodgeForum@yahoogroups.com [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of Henry Jay Hannigan
Sent: Tuesday, September 09, 2008 7:09 AM
To: WanderlodgeForum@yahoogroups.com
Subject: [WanderlodgeForum] Re: Refrigerator cooling fans

I've been in Vegas all summer..ave temp over 103 every day...dometic
fridge worked fine..NO fan..more than 3inches behind coils in my
bird.....
Regards,
Hank
90SP36

--- In "WanderlodgeForum%40yahoogroups.com", "Kurt Horvath"
...> wrote:
>
> Me to Gregg,I cut and pasted this from my post 33990
>
> Photos of Exhaust Vent Fans are in my album , (bumpersbird) bottom
of
> page two and top of page three.
>
> The goal is to move air past the cooling coil mounted on the rear of
> the fridge, in my case a Dometic RM 7030. I have an angled setup
> with an enormous space behind the refer. It is recommended that
> there be no more than 1" a space behind the fridge to facilitate
> convection for cooling the coils. Well I'm not one to reinvent the
> wheel so I wasn't going to pull out the fridge to build a baffle
> system, the recommended fix.
>
> This won't be so much of a problem for you if your fridge is
> 1" or less from the wall behind it. The origonal fan and snap
> thermostat set up should work good if it's all there and working.
>
> To move a sufficient amount of air past the coils. You have two
> choices you can suck or blow. Blowing is not recommended, but it
> works.
>
> Greg's system is set up this way and after a little tweeking it
> works fine.
>
> So how do you suck enough air volume past the coils to make a
> difference? I not an engineer so I went for POWER!
>
> You know the old saying. Put enough thrust behind anything and it
> will fly.
>
> I mounted 5 - 130 CFM computer fans inside the flue vent on the
> roof.
>
>
http://autos.ph.groups.yahoo.com/group/WanderlodgeForum/photos/view/7
> 006?b=29
>
> I got a marine style switch with a four switch/breaker combo. I
> chose waterproof because I mounted it on the cabinet near the sink
in
> the bathroom and because its high quality and most of all because it
> looks cool.
>
>
http://autos.ph.groups.yahoo.com/group/WanderlodgeForum/photos/view/7
> 006?b=32
>
> I tagged into the 12V power leading into the fridge.
>
>
http://autos.ph.groups.yahoo.com/group/WanderlodgeForum/photos/view/7
> 006?b=30
>
> Not a big draw for the fans and the fridge doesn't draw anywhere
> near the 20 amps supplied to it. I used 2 of the 4 switches leaving
> 2 for future use. I wired the switches, #1 runs 2 fans, #2 runs 3
> fans so I have the capability to run 2 fans @ 260 cfm, 3 fans@ 390
> cfm or 5 fans@ 650 cfm.
>
> Yes if you're standing near the access hatch you know its working.
On
> a calm day it will suck in cigar smoke in from 12" to 14" away.
>
> I also mounted 4 fans in the fridge that blow air across the cooling
> fins inside the fridge and of course they circulate the internal
air.
>
>
http://autos.ph.groups.yahoo.com/group/WanderlodgeForum/photos/view/7
> 006?b=33
>
> They are powered from the internal light assembly and mounted in
> pairs they are quite nice. I got them from a guy on e-bay. Once you
> see these little jewels you'll want them to. I check e-bay for this
> guy and he's not making any fans at this time
>
> The only problem I had was getting the wiring up to the fans. I used
> a piece of pvc pipe I don't remember the size I just grabbed some
> pipe that was laying around the barn and some mounting clamps,
> inserting the require wires into the conduit before mounting the
> conduit to the wood walls.
>
>
http://autos.ph.groups.yahoo.com/group/WanderlodgeForum/photos/view/7
> 006?b=31
>
> I poked a hole up through the protective
> screen in the flue vent, keeping it smaller than the diameter of the
> pipe so it has a good grip on it. I had to drill one hole through
the
> wall to run the wires into the bathroom. A glob of silicon sealed
the
> hole and holds things firmly to prevent chaffing. I also used wire
> loom where possible. Problem solved.
>
> So far so good, this summer will tell if its working as well as I
> think it will. I have already had to set the thermostat up to keep
> everything on the lower shelves from freezing.
>
> Is it noisy? Yes
> Is it bothersome? Somewhat
> Choice between noise and cold beer? Only you can answer that.
>
> The fans are the big computer fans 4.7" @130cfm. There are fans of
> this size that have a lower cfm and are much quieter to operate. I
> have used these same fans to replace the blowers on some of my
> heaters and they are quiet compared to the fridge set up. The only
> thing I can think of is the fridge cabinet is hollow it may amplify
> the noise.
>
> This post is a little long and may not help a lot in your
> application, but if you have a big space behind the fridge this will
> work.
>
> Kurt Horvath
> 95 PT-42 WLWB
>
>
>
>
>
>
>
>
> --- In "WanderlodgeForum%40yahoogroups.com", "Gregory OConnor"
> wrote:
> >
> > I dont think the advantage is cool air over the coil as much as
it
> > is removing hot air from the compartment. heat is a necessary
part
> > of Einstines amonia evaporation process and it is important to
> > maintain a gradual cooling. I put a fan ducted to blow in the
> > compartmet but others (I think Ryan or Scott) have a fan at the
> > exhaust which would also remove the chance that blowing in will
> > pressurizing the compartment and push un burned lpg into the bus.
> >
> > GregoryO'Connor
> > 94ptRomolandCa
> >
> > --- In "WanderlodgeForum%40yahoogroups.com", "Chet Geist"
> > wrote:
> > >
> > > Thanks to all for the advise. I did jump the snap thermal
switch
> > on one of
> > > the fans and it runs fine. The refrigerator seemed to cool a
> > little better
> > > this afternoon, but that was just a short test with only 95
degree
> > > temperature outside. I will probably bypass the thermal on the
> > other fan
> > > soon and see if that is a good solution. I will also pull one
of
> > the
> > > thermal switches and see if I can get a number or something off
> of
> > it and
> > > then buy two new ones.
> > >
> > > Have been packing today to go to the Texas coast on Thursday
and
> > wouldn't
> > > you know it here comes Ike. May have to change plans again.
> > Dolly screwed
> > > up the last trip.
> > >
> > > Chet Geist
> > > 1981 FC33, Austin, Texas
> > >
> > >
> > > -----Original Message-----
> > > From: "WanderlodgeForum%40yahoogroups.com"
> > > [mailto:"WanderlodgeForum%40yahoogroups.com"]On Behalf Of joepat50
> > > Sent: Monday, September 08, 2008 7:35 PM
> > > To: "WanderlodgeForum%40yahoogroups.com"
> > > Subject: [WanderlodgeForum] Re: Refrigerator cooling fans
> > >
> > >
> > > You could try jumping them out and see if the fans start. If
> not
> > the
> > > fan may be NG.
> > > If the switch is bad I got a dozen off ebay for a fan to cool
> the
> > > charger compartment where Im putting an inverter. Supposed to
> > close
> > > at 45 dC or about 115dF. If you want one let me know and I'll
> > send
> > > one out...
> > >
> > > /Joe
> > >
> > > --- In "WanderlodgeForum%40yahoogroups.com", "chetgeist"
> > wrote:
> > > >
> > > > Behind my refrigerator are two small 12 volt fans that have
> 12
> > volts
> > > > to them. They are equipped with a small button thermal
> switch.
> > I am
> > > > assuming these fans should come on when the temperature
> behind
> > the
> > > > refrigerator gets above a certain temperature. Mine never
> seem
> > to run
> > > > even when it is 100 degrees outside and the sum is shining
on
> > that
> > > > side of the coach. Does anyone know the reason why they do
> not
> > run?
> > > > Does anyone know at what temperature these button thermal
> > switches
> > > > kick in? Yes I have the switch in the galley set to "on".
> > > >
> > > > Chet Geist
> > > > 1981 FC33, Austin, Texas
> > > >
> > >
> >
>