Dometic Fridge in Slideout Cooling issue-resolution

[coneslayer]

Thanks to many posts online in this and many other locations for helping resolve our fridge cooling problem.
2017 Rockwood 8299BS. 4 door 1350SLMX Dometic.
Fridge after almost 48 hours in 85-90' heat would just not stay cool, 41-49' temps was best we would get. Open door temps rise quickly and take forever to drop a degree or two.
The genius designers who think heat moves in horizontal directions need to do a bit more research with some engineers to figure out a better way to dissipate the heat above the coils.
I found an electronics store while camping in Niagara Falls and purchased two 5" CPU 12v DC fans and some wire. Temporary install hanging with some tie wraps but it worked really well. It sucked out that hot air in the dead space and our fridge went from 45' to 40' in about 1-2 hours. Got down to 38' a couple hours later and maintained that temp through the hottest part of the day. By the next morning fridge was down to 34'.
Plan to do a more constructive install with some brackets, thermistor, relay and emergency cooling bypass switch(so I can bypass thermistor in case of very warm ambient temps).
Why in the heck the OEM didn't install something like this in the first place? IDK.

[Carverjim]

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[Bama Rambler]

Thanks for the write-up. Especially the picture. It helps to visualize how to remedy the problem so many have with these slide mounted fridges.

[coneslayer]

Update: So here are some pics of the final install. Unfortunately, there is something else wrong with the cooling unit because it just stopped working. RV dealer verified that yes, the "coolant" was not moving through the cooling unit coils and it has to be replaced. Luckily under warranty. The RV dealer was very helpful when I told them I wanted to permanently install cooling fans to improve the efficiency of the system and contacted Forest River for approval, to not void warranty. Which Forest River granted in writing, so that is good. As long as not obstructing the system flow or modifying the actual fridge itself.

Unfortunately I had to remove this assembly so they can work on replacing the cooling unit, but will go back in as soon as that is done.

I used galvanized roll strapping to make a bracket. Which goes in between the upper mounting tabs of the upper exhaust bezel. There are L shaped compression brackets. Aligned the holes in the strapping (had to drill one extra in the strap) with the three brackets on the bezel, and bend the strap a bit to form into the L. Bent the strap at an angle so the fans can suck hot air from the top and blow out the vent holes at same angle of the vents are shaped. 8x32 bolts with washers and self locking nuts.
Made my harness and wrapped the harness in split loom which I always have a bunch laying around(electronics engineer) for projects.
Used a three way automotive switch. Made a ground, and there is an input 12v input on the main relay on back wall of fridge. Of course used inline fuses.( I will try to create a simple schematic for the wiring).

The switch is wired so that the center(common) is the 12v out to the fans. One side of switch is 12v constant and the other is 12v sense off the thermistor feed(side that feeds stock fans). The thermistor is standard spade terminal so you can get a coupler spade terminal to feed the switch or do a scotchlock tap(make sure you fuse it, 1 or 2amp).

[Platokidd]

I have the 1350rm fridge.
The biggest improvement I made was stuffing the dead airspace above and on side of fridge with insulation. Made a bowed deflector to help force the air flow out the top out of sheet metal above the cooling coil.
Added a inside fridge fan and outside fan running fulltime to the 2 fans it had.
According to Dometic install sheet, prime time did not install the fridge correctly.
Seems to be quite common in the rv industry and fridge installs.

[coneslayer]

Originally Posted by Platokidd

I have the 1350rm fridge.
The biggest improvement I made was stuffing the dead airspace above and on side of fridge with insulation. Made a bowed deflector to help force the air flow out the top out of sheet metal above the cooling coil.
Added a inside fridge fan and outside fan running fulltime to the 2 fans it had.
According to Dometic install sheet, prime time did not install the fridge correctly.
Seems to be quite common in the rv industry and fridge installs.

I like that idea of stuffing the headspace with insulation. Also have seen people make a curved shield up there. What did you use to keep the insulation from falling down while traveling? Any pics to help out on this string?

Luckily we have a motel sized fridge/freezer to use while waiting for ours to get fixed. I have a commercial style invertor in my pickup that we plugged it into on our trip to keep it cold. Half tempted to rip this rv fridge out and go with a residential style. Put an inverter in that I could use to run just the circuit the fridge is on.

[richp]

Hi,

I inserted a section of pool noodle in the gap above the refer to block off that dead air space. Nice and tight, low cost, no fabrication required.

FWIW.

Rich Phillips

[dblr]

Originally Posted by richp

Hi,

I inserted a section of pool noodle in the gap above the refer to block off that dead air space. Nice and tight, low cost, no fabrication required.

FWIW.

Rich Phillips

Yet another use for pool noodles, pretty soon we will need a thread just for that, good thinking.

[aceinspp]

Originally Posted by dblr

Yet another use for pool noodles, pretty soon we will need a thread just for that, good thinking.

Yep used them on my 5er slide outs. And the folks that make them are going to jack up the price due multipurpose use. Later RJD

[coneslayer]

Love it! We need a like button on here. Great idea