cancel
Showing results forย 
Search instead forย 
Did you mean:ย 

Fridge cooling fan mod

EnochLight
Explorer
Explorer
Hello everyone,

I thought I'd share my experience with building and installing an exterior fan mod for my Dometic RM2351 fridge in our travel trailer. I'm doing this in the hopes that it will keep my fridge at a safe temp when the vent side is facing the sun and it's 85F-90F outside (a common temperature range for our trips in the Michigan/Ohio area).

From the factory, it cools great when it's in the shade and it's not more than 70F outside. But once the day starts to heat up, the interior temps have gotten as high as the low 50's - clearly not a safe place to keep food!

Anyway, I looked at various after market 3rd party fan kits already sold, such as the solar version from Camco and a few others. I felt like I could do something much more powerful at a much lower cost with computer case fans, so here's what I did...

For starters, here's the exterior of my TT's vent-side, where the rear of the fridge is located:



Unfortunately, there appears to be some dead space above the fridge, as I discovered when I pulled the panels off. It looks kind of like this:



Anyway, what I intended to build was a 4-fan array supported by two aluminum L-brackets that I got at Home Depot. They would direct air out of the top vent like this:



The computer case fans are standard 80mm, push about 30+ CFM, and draw about .15A each on the 12 volt rail. I decided to do a test run by plugging them into the 120v line (sharing the same plug as the fridge) by using a 12 volt Molex adapter (available at Newegg and/or Amazon, etc). Here's the fans:



So I began to take the panel off by unscrewing it and carefully cutting the silicon seal around the edge. Must be careful - I accidentally gouged out my paint on the top in one small area! ๐Ÿ˜ž







With the panel removed, I discovered that the evaporator cooling fins were placed a lot higher than I originally thought. I was planning to mount the fans pointing up and using directional chute vents to direct the air out at a curved 90 degree angle, but due to space constraints I had to mount them in the front blowing air straight out. I measured about 22" width, cut my aluminum L-brackets to length, and hand assembled them for a trial fit:









I began by setting the fans in the L-Brackets and drilling a marker hole with a bit much smaller than the diameter of the case fans. Then I set them aside and drilled a hole large enough to get a #10 32x1/2" round head screw through the L-Bracket loosely and torquing them down into the fan frames to hold the whole assembly together. One by one I screwed them together - the end result is quite sturdy:









I was going to solder everything together, but decided to use a European-style terminal strip (from RadioShack) so that I could easily replace the fans if one went bad. Initially I just wired them all into one termination point as I didn't want to go through the hassle of doing them one by one for my initial "dry run":





The finished array turned out like this (though I will eventually wire each one into its own terminus in the strip, tidy up the wires, etc, should it work OK:



I mounted it right in front of the fins, with the directional chutes all blowing out and slightly down in an effort to curtail moisture from falling down into the fans when it rains hard. You can see in the second pic that the fan array sits right on top of the cooling fins:





I let it run last night starting at about 8:30 PM, when it was about 82F outside. When I got up this morning, it was a chilly 35F inside:



But unfortunately, when it hit around 2:15 PM today I checked again. The temperature had climbed to 42F, which is unsafe for proper food storage. Hmmmm....



That said, it was about 84F today and sunny. Normally my fridge temp would be climbing closer to the high 40's/low 50's, so it does appear to be aiding in cooling - just not as good as I had hoped. Next I will try filling the dead air space above the fridge, and then adding a second interior fan blowing off of the inside cooling fins.

Right now I utilize one of those battery operated Camco fridge fans, but it doesn't really blow air onto the inside cooling fins.

So... all in all... I'm a little disappointed, but still hopeful. Total cost for building this was under $70 in parts, and I thought that pushing almost 120 CFM in such a small area would definitely solve my issue.... but it didn't.

Oh and, as far as noise - they are barely audible running at full RPM. If I do end up keeping this on and hard wiring it into my 12-volt system, I'll likely just put an on/off switch on the rear when I wire it up. That said... getting power to my interior fan idea is a whole other problem. No internal light or power source, so I'll have to do some drilling into my fridge wall - which scares me.
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited
49 REPLIES 49

EnochLight
Explorer
Explorer
beemerphile1 wrote:
Hopefully you started with the basics.

Clean the chimney?
Clean the burner?
Clean the burner jet/orifice?
Verify the correct LPG pressure?

When I had trouble one thing I found was that the pressure was only 9".


Hello,

This rig is barely a year old - very clean. Chimney is clear, burner is like new, nothing in jet/orifice. That said, I'm not even running it on LPG right now - I'm plugged into shore power in my driveway trying to get it to work on electric.

Thanks
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

beemerphile1
Explorer
Explorer
Hopefully you started with the basics.

Clean the chimney?
Clean the burner?
Clean the burner jet/orifice?
Verify the correct LPG pressure?

When I had trouble one thing I found was that the pressure was only 9".
Build a life you don't need a vacation from.

2016 Silverado 3500HD DRW D/A 4x4
2018 Keystone Cougar 26RBS
2006 Weekend Warrior FK1900

EnochLight
Explorer
Explorer
mhardin wrote:
Have you checked the thermistor? It could be bad, or just located wrong.


I tried moving it up the inside fin that it's mounted on. Seemed to drop the max low temp by a couple of degrees.
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

mhardin
Explorer
Explorer
Have you checked the thermistor? It could be bad, or just located wrong.
2013 Ford F-350, 4x4, Crew Cab, Long Box.
2001 Jayco Eagle 266 FBS.
2014 Heartland Elkridge 37 Ultimate.

EnochLight
Explorer
Explorer
cpaharley2008 wrote:
Have you tried the fridge fix? Over on the FG RV forum and Escape forums we have similar issues and have had some success with this: http://www.smartrvproducts.com


No I haven't. I've never even heard of this product before; thanks. I am reluctant to purchase it and spend time and effort on the mod because I have a Dometic RM2351, and that model is not listed as compatible. ๐Ÿ˜ž

*UPDATE*

I just spoke to them. Their fan kit does not fit the smaller RM2351 model that I have. They are planning to manufacture a smaller version that doesn't have LED lights in 1-2 months, though.
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

cpaharley2008
Explorer
Explorer
Have you tried the fridge fix? Over on the FG RV forum and Escape forums we have similar issues and have had some success with this: http://www.smartrvproducts.com
2009 Dodge Ram Hemi 4x4 11,300miles- lifetime warranty
2012 Toyota FJ-500 miles
2014 Escape 21' All Season trailer

EnochLight
Explorer
Explorer
JJBIRISH wrote:
Are you sure the statement that just because a little of something is good, doesnโ€™t mean that a lot of it is any better wouldnโ€™t apply hereโ€ฆ

For the fridge to work properly it has to be operated level when stationaryโ€ฆ
It needs good ventilationโ€ฆ
And it needs a precise amount of heatโ€ฆ

I am sure you are someone that likes to do it yourself, do nice and neat work for sure, but this looks like a new unit, possibly under warrantyโ€ฆ if so why not allow the mfg. to repair or replace itโ€ฆ before they can use your mods as a reason for its failureโ€ฆ
(This warranty will be in effect for three years on parts and freight and two years on labor from the date of purchase by the Original Purchaser. It is suggested that the original purchaser retain a copy of the dated bill of sale as evidence of the date ofpurchase.)

Good ventilation would not require that the rear area be converted to a wind tunnel, and might actually alter the precise and required amount of heat needed to perk properlyโ€ฆ maybe the preset temperature control is just faultyโ€ฆ

https://www.dometic.com/f3c9a8a0-14cb-4ab6-8285-f28488b1cdbc.fodoc


All very good points. My fridge is level (and stationary), seems to have correct ventilation with my mod, and seems to heat OK.

It's just that after reading about RV fridge experiences here on this forum, I just assumed this was a common characteristic of all RV fridges (hence the amount of mods you see with their operation).

My Gulfstream has a 2 year warranty, but from what I understand all appliance warranties default to the appliance manufacturer. That said, if it's determined that Gulfstream installed it wrong (too much dead space in the upper compartment; no baffles; too much space between the fridge's rear coils and the wall of the RV), then it's likely Dometic would state that the manufacturer needs to cover everything. These are all assumptions on my part.

My issue is the time required to get it addressed at a dealer. We have a weeklong trip planned the first week of August, and then another for Labor Day weekend. I know that having your RV in for service can be time consuming, depending on the issue. I just thought I'd attempt to remedy the issue myself, affordably, before resorting to dealer service.

Looks like my options have run out, though. ๐Ÿ˜ž
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

JJBIRISH
Explorer
Explorer
EnochLight wrote:
**UPDATE**

So.. after repositioning my 4-fan array pointing up and into the evaporator fins and adding an upper baffle to force air out of the upper vent, my interior fridge still hit 42F today on a 74F partially sunny day.

Very frustrated. ๐Ÿ˜ž



Are you sure the statement that just because a little of something is good, doesnโ€™t mean that a lot of it is any better wouldnโ€™t apply hereโ€ฆ

For the fridge to work properly it has to be operated level when stationaryโ€ฆ
It needs good ventilationโ€ฆ
And it needs a precise amount of heatโ€ฆ

I am sure you are someone that likes to do it yourself, do nice and neat work for sure, but this looks like a new unit, possibly under warrantyโ€ฆ if so why not allow the mfg. to repair or replace itโ€ฆ before they can use your mods as a reason for its failureโ€ฆ
(This warranty will be in effect for three years on parts and freight and two years on labor from the date of purchase by the Original Purchaser. It is suggested that the original purchaser retain a copy of the dated bill of sale as evidence of the date ofpurchase.)

Good ventilation would not require that the rear area be converted to a wind tunnel, and might actually alter the precise and required amount of heat needed to perk properlyโ€ฆ maybe the preset temperature control is just faultyโ€ฆ

https://www.dometic.com/f3c9a8a0-14cb-4ab6-8285-f28488b1cdbc.fodoc
Love my mass produced, entry level, built by Lazy American Workers, Hornet

EnochLight
Explorer
Explorer
**UPDATE**

So.. after repositioning my 4-fan array pointing up and into the evaporator fins and adding an upper baffle to force air out of the upper vent, my interior fridge still hit 42F today on a 74F partially sunny day.

Very frustrated. ๐Ÿ˜ž
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

EnochLight
Explorer
Explorer
'tiredTeacher wrote:
EnochLight wrote:
Curious - could you elaborate more on this?

Wow! Now you have it right. That'll do the job.
As for the dividing baffle, there is more space between my pop up reefer's guts and the outer wall of the camper than you have. Your fans are where I had to put a baffle.

You're good-to-go.

Teach


Ah OK, thanks! We'll see how this goes. Although I can't feel a strong current of air (like I did with the chutes) now that I put the top vent cover on, just adding that baffle seems to be forcing more air all around to exhaust from the vent. Hopefully this will do the trick. If not, I'll consider adding an additional top baffle between the exterior wall and the edge of the fan array, so air being pulled through the condenser fins will literally be the only path it can take from the lower compartment.

I do worry a little about the fan that's to the extreme right, as it appears as though it will draw exhaust air over from the burner/boiler flute - and that get's crazy hot.
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

_tiredTeacher
Explorer II
Explorer II
EnochLight wrote:
Curious - could you elaborate more on this?

Wow! Now you have it right. That'll do the job.
As for the dividing baffle, there is more space between my pop up reefer's guts and the outer wall of the camper than you have. Your fans are where I had to put a baffle.

You're good-to-go.

Teach
Wright and Penny
2010 Tundra 4X4
2014 Rockwood 2604WS
"Life is a cruel teacher. She gives the test first; the lesson then follows."

EnochLight
Explorer
Explorer
popeyemth wrote:
Many big box stores and most farm supply stores sell 24" squares of thin sheet metal and aluminum.
Roll roof flashing comes 24" wide in aluminum too.
Good Luck, Mike


Thanks. I actually already have a 24" piece of aluminum sheet metal. I just wanted to try it out in cardboard to see if it works before I go through the trouble of metal working. Also trying to see if Teach can illustrate what he meant by separating the upper and lower compartment with a baffle.
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

popeyemth
Explorer
Explorer
Many big box stores and most farm supply stores sell 24" squares of thin sheet metal and aluminum.
Roll roof flashing comes 24" wide in aluminum too.
Good Luck, Mike
"wine is a constant proof that God loves us, and loves to see us happy" ben franklin

EnochLight
Explorer
Explorer
'tiredTeacher wrote:
One more thought. It is more difficult to PULL air across those coils than it is to BLOW the air. On my Pop up, I put the fan under the coil and blew the air up and out, drawing from the lower vent.


So, your recommendation was stuck in my mind while I was at work today, so the moment I got home and got dinner finished I took it upon myself to try this approach. I had to remove all of my directional chutes and one side of the aluminum L-bar, but I was able to get all 4 fans directly below the evap fins, pointing up. I then fashioned a (temp) upper baffle out of cardboard and duct tape to eliminate the dead space above the food compartment and direct the air out of the entire upper vent cavity.

'tiredTeacher wrote:
I also added a baffle to separate the lower compartment from the upper.

Teach


Curious - could you elaborate more on this? Is it possible for you to take a photo of your setup and post it here? I'm not sure what you mean by separating the lower and upper compartment.

All that said, in a very strange turn of events, this July in lower Michigan has turned out to be unusually cold - as it's currently 64F outside at 9PM and is going to drop to the mid-50's tonight (it's normally mid 80's to lower 90's in this area and mid 70's at night). So I'm not going to be able to get an accurate feel of how this temporary mod works until it heats up again (projecting low 80's again by the weekend).

This is unfortunate, as we are leaving Monday to go for a weeklong camping trip in Ohio and I wanted to have my temporary mod settled into a permanent mod before the trip. :s Guess I'll have to test this setup "in the field"! ๐Ÿ˜„

Here's new pics of what I did:





I'm almost embarrassed about the cardboard baffle, but it's really just a test run to see if it works. That said, I can't run this off of propane until I wrap at least part of it. The burner stack is just too close for my comfort.

2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited

EnochLight
Explorer
Explorer
'tiredTeacher wrote:

Four years ago, I wrapped my cardboard baffle in aluminum foil. Not a problem with it so far.(Did I mention that was 4 years ago?) ๐Ÿ™‚

Teach


Good to know. Thanks!
2013 Gulfstream Amerilite 16BHC Travel Trailer pulled with a 2008 Ford Escape Limited