This post contains affiliate links.
Traveling in an RV offers all the comforts of home with the freedom to not be tied to one location. This mobility, however, does come without its own considerations. Things that are taken for granted in a stationary home may be issues that require constant monitoring and consideration when in a recreational vehicle. Your RV fridge, for example, needs to be relatively level in order to work properly.
Why does your RV fridge need to be level? Your RV fridge is most likely an absorption refrigerator which relies on gravity for the ammonia liquid to fall from the condenser fins to the evaporator coils where the cooling process takes place. Running the fridge on an unlevel surface for more than half an hour can damage the refrigerator.
This damage may not be immediate but will cause significant wear and tear over time. Of course, there are different types of RV fridges, and each has its own advantages and disadvantages. In order to know the best practices, you need to know what type of fridge you have and how it works.
Table of Contents
How an RV Fridge Works
Depending on your RV manufacturer the terms used to describe the type of refrigerator in your recreational vehicle may vary. It’s important to know what style your RV fridge is because each type works differently and the best practices for using each change drastically between types. Generally, the types of recreational vehicle refrigerators are
- absorption refrigerators
- compressor refrigerators
- 3-way refrigerators
Absorption Refrigerators
The most common RV fridge is the absorption refrigerator because it can use propane or AC power. When you are parked at a developed RV campsite, you can plug into the power grid and run your appliances as you would in a standard home. When you are on the move or staying at a campsite off the grid you can use propane instead, increasing the mobility of your RV.
An absorption refrigerator uses ammonia, water, and hydrogen gas to create a cooling effect.
- The refrigerators boiler (heated by propane or electric heat) turns the liquid ammonia into a gas.
- The ammonia vapor rises to the condenser fins at the top of the refrigerator.
- In the fins, heat is allowed to escape from the ammonia vapor, which cools into ammonia liquid.
- The ammonia liquid falls (via gravity) to the evaporator coils in the refrigerator’s cooling unit.
- The evaporator coils pass near the fridge box. The heat from inside the fridge box is transferred to the liquid ammonia in the evaporator coils, leaving the storage section cool. The ammonia liquid, in turn, is heated to gas.
- The ammonia vapor flows into an absorber which releases the heat and turns the ammonia back into a liquid
It’s step 4 that makes it critical that an absorption refrigerator is level. The fridge needs to be level so that the ammonia liquid falls from the condenser fins at the top of the refrigerator to the evaporator coils at the bottom. The more uneven the fridge is, the less efficiently the ammonia liquid will travel, not only decreasing the fridge’s ability to cool food, but also causing damage to the unit over time.
For a more detailed description of how an absorption refrigerator works, read my article Decoding Your RV Fridge – How It Works
Compressor Refrigerators
While the general process of cooling in a compressor refrigerator is mostly the same as in an absorption refrigerator, the critical difference is that the former has a compressor that moves the ammonia liquid from the condenser fins to the evaporator coils via hydraulic pressure instead of by gravity.
To accomplish this, however, the compressor refrigerator needs a constant source of power. This is usually an Alternating Current (AC) source, though it could be supplied by a Direct Current (DC) if your RV is equipped with an inverter.
Compressor refrigerators tend to cool faster and efficiently and are not affected by altitude. They are, however, more dependant on a consistent source of electricity, and therefore better suited for those who stay mostly at developed RV sites.
2-Way and 3-Way Refrigerators
A 3-way refrigerator usually refers to an absorption refrigerator (meaning it does not have a compressor) that can run off of AC, DC, or propane power. This type of fridge is incredibly versatile because it can run while plugged in, off battery power, or via propane, but it does need to be relatively level to work properly.
A 2-way refrigerator is very similar but can only run off of AC power or propane. While it still allows you to the freedom to camp off-grid you will be using propane to keep your beer cold.
Residential Refrigerators
There are two common definitions of “residential refrigerators” that can cause a bit of confusion. In its purest form, referring to an RV fridge as a residential refrigerator means that it works in the same way as the type of refrigerator found in a standard home, meaning a compression refrigerator, but sized down to fit in your recreational vehicle.
The other common use of the term “residential refrigerator” is any RV fridge that offers more than the expected amount of storage and cooling space. Using the term “residential refrigerator” in this way is a sales tactic to promote how much food can be kept cooled, but does nothing to inform the buyer how the refrigerator works and, therefore, the best practices when it comes to keeping the fridge level.
How Level Does Your RV Fridge Need to Be?
Older models need to be mostly level to work properly, though as technology advances RV fridges are more forgiving in terms of how level they need to be. Most recreational refrigerators will work properly as long as they are within 2 degrees of level side to side and 4 degrees of level front to back. More modern models of RV fridges are more forgiving, allowing for proper operation within 3 degrees of level side to side and 6 degrees of level front to back.
Front to back and side to side, in this case, are defined by looking at the refrigerator facing the front (or back) of the unit. When translating to the overall leveling of the RV as a whole, therefore, side to side typically means the front and rear, and front to back typically means the right and left side of the RV.
A good rule of thumb is as long as half the bubble is within the center when leveling your RV fridge, it should run properly.
Many people have extrapolated how off kilter 3 degrees of level would equate to based on the length of their recreational vehicle. It comes to more than half an inch difference in height per foot of length trailer. This means that if your trailer is 22 feet long, one end would be almost 14 inches higher than the other in order to be more than 3 degrees off level.
This has led many people to suggest that if it looks level and you are comfortable walking and sleeping in your RV, it is level enough for the fridge to function properly. This, however, is a highly subjective form of measurement.
The human eye is notoriously unreliable at judging depth and relative levelness, especially if there are variations of light and other factors. Also, different people are variably perceptive to slope and gradation. Some people will notice if the ground is only slightly off level while others will not notice until the ground is significantly off level.
There’s also something to be said for the fact that even if your RV fridge seems to be running sufficiently, that doesn’t mean that it isn’t sustaining some amount of damage that will reduce its operational life over time. Therefore you should try to keep your RV fridge as level as possible at all times.
Furthermore, the fridge is tilted such that the boiler side is slightly lower. The boiler is typically on the left side of the fridge, though it’s sometimes more or less centered. If the fridge is tilted in such a way that the boiler is lower it may work even better than if it were level. If it’s tilted in the opposite direction, such that the return line is lower than the boiler, however, the liquid ammonia will not be able to travel uphill.
How Running an RV on an Unlevel Surface Damages the Refrigerator
Because an absorption refrigerator depends on the free movement of ammonia via gravity in order to work properly, running an RV fridge on an unlevel surface can cause significant damage.
One way running an unlevel RV fridge can cause damage is by the overheating of various components. When the fluids are not flowing in a way that is optimal for the capture and release of heat, blockages can occur resulting in certain elements of the cooling system overheating.
When working properly, the boiler heats the ammonia to 350 degrees Fahrenheit. When malfunctioning, temperatures can rise significantly higher, putting a lot of stress on the infrastructure. Overheating in this way can warp the materials composing the tubes, coils, and fins that contain the hot liquids and vapors.
Another way that an overheated RV fridge can be damaged is the formation of ammonia crystals. In an unlevel RV fridge, when the ammonia vapor in the condenser fins cools to a liquid, but the liquid ammonia isn’t able to fall (via gravity) all the way to evaporator coils, it may instead collect in the tubing between the two and instead form ammonia crystals.
These crystals (the solid form of ammonia) can clog the circulatory system of the refrigerator in the same way that cholesterol clogs the arteries of a person.
How to Level an RV Fridge
RV fridges should be mounted within your recreational vehicle in such a way that if the RV is level, the fridge should be as well. As such, the first step to leveling the RV fridge is to level the RV itself.
Some RVs come equipped with auto-leveling jacks. These can be quick and convenient ways to level an RV, but they can also become uncalibrated over time, resulting in an unlevel RV.
You can also level your RV manually, with the assistance of simple blocks or sophisticated lego-like leveling kits that can be used to wedge under the wheels of the RV until even. It’s best to level an RV side to side first, and then front to back.
When leveling an RV fridge, it’s important to note that some levels are better than others. Small, round dot levels are convenient but can be very inaccurate. Similarly, uncalibrated bubble levels do not offer much specificity when leveling your fridge. A simple torpedo level and/or graduated bubble levels are inexpensive and effective for ensuring your RV fridge is level.
When leveling your RV fridge, you only want to use the freezer section because it made of metal and thus the least likely section to warp.
Other parts of your RV fridge are susceptible to warping. Plastic racks can bend under the weight of stored food. The foam pack inside the walls can absorb water over time and swell. The metal in the freezer, on the other hand, is most likely to stay truly straight over the years.
You want to place your torpedo level against the metal in the freezer section of the RV, first front to back, and then side to side, adjusting the balance until it is as level as possible.
If you are interested in learning more about leveling your RV, check out my article Why RV’s Need to Be Level and How to Know Your Level is Level
Is it Safe to Run Your RV Fridge While Driving?
Ideally, you would never run your RV fridge when it wasn’t perfectly level. Studies have found that after only 2 or 3 minutes on an unlevel surface, temperatures in the RV refrigerator’s cooling system can spike well above the 350 degrees Fahrenheit norm.
Because an absorption refrigerator uses gravity to move ammonia liquid to the evaporator coils, it is generally safe to run the fridge while driving because the jostling will cause the liquid to fall even if the RV (and therefore the fridge) is at a steep angle. The exception to this would be, of course, if you find yourself stuck in stand-still traffic at an incline or decline for longer than half an hour.
When you stop to fuel it may be safe to keep your fridge running even if the surface is uneven because it is a relatively short duration. When making longer stops, such as meals and visiting roadside attractions it is best to turn your refrigerator off if the surface isn’t level enough.
Other Benefits of Leveling Your RV
The refrigerator isn’t the only thing that works best when your recreational vehicle is level. The plumbing, which also uses gravity, also works most efficiently when on even ground. Likewise, you’ll find it easier to walk and more comfortable to sleep in a properly leveled RV.
As I mentioned early I have a full article dedicated to why you should level your RV, Why RV’s Need to Be Level and How to Know Your Level is Level.
Will an RV Refrigerator Work if Not Level?
As long as the fridge is relatively upright, enough liquid ammonia will make it from the condenser fins to the evaporator coils to complete the cooling cycle. Just because the fridge is working, however, doesn’t mean it isn’t operating in a way that is overheating or otherwise damaging the appliance in the long run. It’s best to always run an RV fridge as level as possible.
How Long Does it Take for a Camper Refrigerator to Get Cold?
It can take 4 to 6 hours for an RV to start to get cold when first turned on after spending time shut down. More likely it’ll take 24 hours before your fridge and freeze are at the correct temperature.
It’s a good idea to run the fridge for several hours empty before putting anything that might spoil inside. If possible, fill the fridge (and freezer) with food that is already cold (or frozen) to prevent the fridge from having to work overly hard to cool.
Should I Leave my RV Refrigerator on All the Time?
The answer to this question is highly dependent on how you travel and use your RV refrigerator.
If your RV is stationary, it should be safe to operate your fridge continuously provided that you took the time to level it out when you initially parked.
If you are driving, it may depend on your habits. When driving only short distances, your food will likely stay cold while you travel if you choose to turn your refrigerator off. If you travel long distances it may be necessary to run the fridge while driving.
What is the Correct Temperature for an RV Refrigerator?
Food can begin to spoil at any temperature over 40 degrees Fahrenheit. Keeping a small thermometer in the refrigerator can help you monitor if your fridge is working properly and your food is safe.
What Can You Do to Help Your RV Fridge Run Smoothly?
Park in the shade. An RV is essentially a metal box, and when parked in the sun your RV can generate and trap a lot of heat. This will not only increase the temperature of the RV, but also anything inside the RV, including the refrigerator.
Circulate air inside the refrigerator. A small battery-operated fan inside the fridge can help achieve and maintain a cool temperature.
Blow heat away from the fridges’ coils and fins. A refrigerator creates a cool interior by displacing the heat to the outside of the box. Once outside of the fridge, the heat should be whisked away by vents or fans so that more heat can be easily displaced.
Fill a crisper with ice. Even when the fridge is off, it’s still an insulated container, like a cooler. Filling the space with ice will prolong the time the fridge is cold when off.
