Refrigerator Ventilation

A few months after I purchased my Wildcat my refrigerator stopped working. My dealer replaced it under warranty and everything seemed fine until I took a 2 week trip to the western states. The fridge cooled fine when parked and at speeds up to about 55 MPH. But travel any faster and the fridge would start to warm up. I have a digital wireless thermometer in the fridge and it would cool to 32-35 while parked and at slow speeds. But travel 65-75 and the fridge would warm up to about 50. It did not seem to matter whether I ran the fridge on propane or my generator.

I suspected some kind of ventilation problem but wasn't sure. The fridge worked fine most of the time so I figured my dealer would be no help in diagnosing the problem.

Then I read a thread on rv.net about a fellow having the same problem. Several ideas were discussed but the one thing most folks mentioned was ventilation. The tubing and cooling fins on the back of the fridge must be very close to the outside wall. Something like no more than 1/2 inch space between them. This forces the rising air to travel through the tubing and cooling fins in a chimney effect. This same width of a few inches must continue all the way to the roof vent to maintain the chimney effect.

My fridge had a large open space above it. Instead of only a few inches it was more like 16 inches. According to the ventilation experts this can cause an eddy like effect and the hot air pools at the top of the fridge instead of exiting the roof vent and pulling cool air in through the bottom vent.

At Lowes I purchased a 4x8 sheet of styrofoam insulation about 1 inch thick with foil backing on one side. I removed the fridge roof vent. I cut the styrofoam into strips and started stacking them above the fridge. I used silicone caulk as an adhesive to hold them together. I placed one piece vertically with the foil side to the outside facing the hot air flow. This provides one continuous smooth surface to not impede the flow of air and also I figured the foil side would be better for exposure to the hot air. The space is now only a few inches wide.

It has made a difference. In the summer of 2003 I traveled for about 3 weeks in the western states. While running the fridge on the generator it consistently stayed at 32-35 regardless of the outside temperature in Utah or Arizona or the speed I traveled.

I am still having a little problem on propane. However I have read that the behavior can be caused by a missing baffle in the chimney above the propane burner. The baffle holds the heat in the chimney long enough to properly heat the cooling unit. With the baffle missing and at high speeds the heat escapes too quickly from the chimney. I have also read that when replacing a refrigerator the new one does not come with this baffle. The baffle must be removed from the old one and reused. I don't think my dealer reinstalled the old baffle in my new fridge when they replaced it.

I still have to confirm that, but I know my ventilation modification has made a difference.