Summer Heat and RV Refrigerators

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May 23, 2011

So far as full-timers, summer has meant that it was time for us to leave the lands of palm trees and endless sunshine to head North and find cooler weather (the last few years we have gotten our tans during the winter, and then lost them during the summer—the opposite of most people we know who are not full-time RVers or snowbirds).  The location on the Oregon coast where we spent last June and July only hit 70F a half-dozen times while we were there.  However, for personal reasons we have stayed put longer than normal this year, so have been dealing with real summer weather (the high 90s and low 100s with lows around 80—and I won’t even mention the humidity!).

So, this is our first experience with our refrigerator not being able to keep up with us (or, should I say, the heat).

I learned a lot about RV refrigerators over the last few weeks, and feel that this is an appropriate “summer-themed” topic.  For instance, did you know that while house refrigerators work on the concept of adding cold to the inside of the refrigerator and freezer, the RV fridge works on the concept of removing heat from the inside of the refrigerator and freezer?

A very simplified description of the process is that the system heats water and chemicals to a vapor; then, this vapor rises to the freezer where a chemical reaction and cooling/evaporation processes work to remove heat from the freezer.  This returns the ammonia to a gas where it goes through another evaporation process in the refrigerator unit, removing more heat.  The liquid now returns to the boiler and the whole process starts again.

With this in mind, there are 4 major things that you have to battle to help your refrigerator work well in the summer (or any time, but it is more difficult in summer).

NOTE: I am ignoring the leveling issue of older model refrigerators since most of the new models work well as long as the RV is level enough for you to live and walk in comfortably.

The first is to ensure the boiler works well to heat the chemicals and create the vapor (the heat can be from an electric element or LP burner).  If using LP, ensure the burner is clean and working correctly; for electric, ensure the heating element has not degraded.

Item numbers 2 and 3 are related and involve removing the heat from the area behind the fridge.  The heat leaves through the vent in the roof, so you need to ensure there is plenty of airflow pushing the heat out.  One thing you can do is add fans behind the fridge so that the flow is increased.  We found a small battery powered fan at WalMart for $6 that seems to help, and fits in the space; also ensure there is no blockage of the vent.  The other recommendation is to park so that the wall of the RV that is behind the fridge is in the shade.  While this is possible sometimes, it is not always an option (for example, in the summer we prefer our MH to face North to keep the sun out of our front window.  The catch is when the MH faces North, the fridge is on the West side of the MH—getting the afternoon sun).

The 4th item is to ensure the air can flow inside the refrigerator. The heat is removed through the cooling fins, but there is nothing to push this colder air around the inside.  Packing the fridge too full limits the flow of the cool air and causes cold and hot spots.  We found a small battery-powered, box fan for the inside of your refrigerator (we found them at Camping World).  This small fan circulates the air, to help disperse the cold air more evenly.

So, we were able to accomplish 3 of the 4 recommendations (ensuring the heating is adequate, increasing the flow of air pushing heat out of the back of the fridge, and increasing the air flow inside the refrigerator; but we are not able to provide shade on the outside RV wall).  We have seen the temperature in the fridge drop by almost 10 degrees based on our efforts.

I have met more and more people who are installing “home-style” refrigerators into their RVs.  I’m sure  that these are better at keeping things cold, but they use a lot more electricity (you need to ensure you can run them while traveling and not connected to “shore power”), and there are some concerns about the ability of these units to handle the vibration from riding in the RV.  So far, we are planning to stick with the RV unit; but we’ll have to see based on how much time we spend in this hot weather.

Our preferred solution to the affect outdoor temperatures have on the RV refrigerator is to stay in 70-80 degree high temperatures year round!  Of course, that is not always possible; even for us full-timers.

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  1. I've been having the same problem with my older Dometic fridge here in the Mohave Desert. Our temps are cooling down now and the fridge stays at about 20 degrees in the freezer compartment and 40 below. When it was really hot a few weeks ago (110 outside) it was almost impossible to keep the fridge cool enough for food.

    I researched this problem and wanted to know more to be sure my old Dometic wasn't malfunctioning. From what I've been reading, this is normal.
    I did buy a small battery-operated fan which helped some.

  2. Hoby

    Diane, I would say that the fans behind the refrigerator made the biggest impact.

  3. Diane Berry

    Thanks Hoby–these are great ideas. We will definitely be using them this summer!