Refrigerator fans

[bumpersbird]

Ryan,

Cooling the refrigerator compartment.

A quick description, after looking at others solutions and reading
all available info which unfortunately the reference files I had
saved for this project were lost to a computer virus. I added the
address for the photos at each step I hope they come up for you, if
you paste them in the address line they may or may not come up. If
not they 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.

Ryan, 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/W...tos/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/W...tos/view/7
006?b=32

I tagged into the 12V power leading into the fridge.

http://autos.ph.groups.yahoo.com/group/W...tos/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/W...tos/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/W...tos/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