How A Propane RV Fridge Works + Tips To Keep It Cold!

Have you recently bought an RV that comes with a propane fridge and want to know how it works? Perhaps you are considering purchasing a propane RV fridge and want to know more about it?

Or perhaps you can’t quite keep your fridge cool and want some tips? Whatever your reason might be, we have the answer for you! 

How A Propane RV Fridge Works And Tips To Keep It Cold!

We know how stressful it can be to master your RV fridge. It runs differently from a standard fridge and the last thing you want is for the food you have stored to spoil, or your drinks to be warm when you take a much-needed sip. 

So find out today how a propane RV fridge world and grab some much-needed tips to help keep it cold. Get ready to enjoy cold drinks and fresh food on your next road trip! 

The Cooling Process – How Does It Work?

In a rush? Here is our quick answer to how an RV fridge works! 

Ammonia is heated before being evaporated and condensed. Teamed with water and hydrogen it helps to cool the refrigerator. The heating process is completed by either an electrical element or a propane flame.

For most refrigerators, you can choose how it runs and we will look at this in more detail now. 

So to find out how this process works in lots of detail, keep on reading! 

An RV absorption fridge has five components: 

  • The generator
  • The separator
  • The condenser 
  • The evaporator 
  • The absorber 

To cool the fridge, we start as we mentioned earlier, with water and ammonia solution in the generator. The solution is heated by propane or electricity until the ammonia hits boiling point. Next, the solution moves to the separator where it is evaporated.

The evaporation separates the ammonia from the water. 

Water then travels to the absorber. The ammonia gas rises into the condenser where the heat reduces and ammonia returns to its liquid state. The liquid then travels to the evaporator and mixes with hydrogen. 

Once more, the ammonia liquid evaporates and the heat inside the fridge is removed. Your fridge box will now start to cool down. 

The ammonia and hydrogen travel to the absorber where it makes a solution with water. The hydrogen gas then flows back to the evaporator while the ammonia and water travel back to the generator. The process is then repeated! 

Throughout the process, heat is applied to ammonia and water so that it can boil and evaporate. In your fridge, this is done by propane or electricity. For those with propane RV fridges, the likely cause of this heat is propane.

You can find out what heats your fridge by checking the user manual or consulting the manufacturer for more information. 

For refrigerators that use propane as a heat source, there is an open flame that heats the chemicals. Those with electric heat sources tend to have an electric element that provides the heat.

Now that we have covered in detail how your propane RV refrigerator works, let’s take a look at the different types and how we can keep our refrigerators cool! 

What Is The Difference Between A Two Way And Three-Way RV Fridge? 

When we talk about absorption refrigerators, there are two types: a two-way or a three-way RV refrigerator. But what is the difference between them you ask? Let’s find out! 

Two Way RV Refrigerator 

A two-way RV refrigerator comes with a choice of running your fridge on either propane (L.P. Gas) or 120VAC. You can set your unit to ‘auto’ and it will switch from propane to 120VAC when you have plugged in and back to propane again once you unplug. 

It removes any hassle from your life and you won’t need to worry about your refrigerator being off power when your RV isn’t plugged in. It’s ideal for those off-road adventures! 

The switch between the two power sources works seamlessly too. When you switch from electric to propane, a small igniter coil is signaled and sparks. The regulating valve will open and fuel to the coil flows.

Next, the igniter sparks the fuel and the flame to heat the ammonia is lighted. 

When you switch back to your AC electrical power (shore power), the regulating valve closes and the flame extinguishes.

Three-Way Refrigerator 

Three-way refrigerators are similar, but come with the added option of 12VDC power! Not only can you choose between propane and 120VAC, but should you want to, you can run your refrigerator on DC power. 

While this offers you more flexibility. The downside is the high current draw needed on DC power to keep your refrigerator and icebox cold.

It is worth carefully considering whether you will use the DC option or not when deciding between a two-way and three-way refrigerator. 

How To Keep Your Fridge Cool 

So how can we help to keep our refrigerators cool? Well, one of our top tips is to grab a thermometer! Store this in your refrigerator so that you can check your refrigerator and freezer are running at the optimum temperatures.

For a fridge that is between 35 and 40 degrees Fahrenheit and 0 degrees for your freezer. 

We recommend checking the temperature of your fridge and freezer before setting off. If needed, allow some time for them to get to the desired temperature. If they have been off for an extended period, allow 24 hours to do this. 

It’s also worth investing in a small fan that can be kept in your fridge cabinet. Opt for a battery-powered one saving you the running costs of an electric fan. A fan here will help to circulate the cool air and keep your items cooler.

It also takes some of the strain from your refrigerator, reducing its workload. 

Another thing you can do is only put pre-cooled items into your fridge and freezer. We know that this isn’t always possible, but you can do this easily when leaving home and starting your trip.

Using pre-cooled and frozen items means your fridge needs to use less energy as it doesn’t need to cool down any hot items. 

When storing leftovers, be sure to let them fully cool before placing them in your fridge or freezer. Placing hot or warm items into your fridge can raise the internal temperature, meaning it needs to work hard to cool back down! 

Your Fridge And Ambient Temperature 

Your Fridge And Ambient Temperature

The temperature outside can impact the running of your RV refrigerator due to the heat exchanger. Your heat exchanger vents hot air from the earlier absorption process outside so that it can dissipate. Usually, this is problem-free, unless it is steamy outside. 

Ideally, you want the sidewall your refrigerator is on to be in a shaded area to help keep the fridge cool in warmer weather. You will also want to keep the area where your fridge access panel is free from debris too.

This helps to keep the area and the fridge well ventilated and prevents any overheating issues. 

During the cooler temperatures outside, turn your refrigerator up and in the warmer weather, turn it down to a colder setting. This helps to ensure that all your items in the refrigerator stay as cold as possible. 

Usually, refrigerator settings range from 1 to 5. 1 tends to be the warmers and 5 the coolest. Having a thermometer can be handy here to help keep an eye on the refrigerator temperature and make adjustments when necessary. 

Keeping It Level 

Leveling your RV is vital. As your fridge’s cooling system depends on gravity, being out of level can be a serious issue for your fridge. If it is too tilted the chemicals can stop circulating, making your refrigerator less efficient and could cause other problems too!

Ideally, you don’t want to be more than 3 degrees or half a bubble out of level. Running your fridge out of level for as little as 30 minutes can damage your refrigerator and should be avoided where possible!

There are plenty of tutorials online you can follow to check if your RV and fridge are level and how you can make them level if they aren’t. We recommend searching for your RV’s make and model for accurate guidance on how to do this. 

Related: How to fix an RV Fridge That Freezes Everything.

Can I Drive With My Fridge Running? 

Some drivers worry about driving with their RV fridge running, which is understandable given that there is an open flame in the fridge. Many wonder if you can drive with the fridge running. What is the answer? 

There’s a lot of debate here. Many RV owners will keep their fridge running while they drive, while others turn it off. We have left ours on and not experienced any issues, but that doesn’t mean it is 100% safe. 

It is best to check the user manual of your refrigerator or to speak to the manufacturer directly. Follow their advice regarding the refrigerator to ensure your safety. 

For those with a three-way RV fridge, this is less of a concern, as you can set it to the 12VDC setting and drive without any worries. We would recommend doing this before setting off, and double-checking that it is on the correct setting so that you don’t need to stress while you drive. 

While some people are concerned about driving with their fridge running, it’s worth noting that the motion of the RV will keep the chemicals moving and help the fridge work properly while you travel.

As the refrigerator is an absorption fridge too, you don’t need to worry about any bumps in the road causing issues. It will continue to run as normal. 

And for those that would prefer to turn their refrigerators off, that is fine too! Roughly, you will lose 4 degrees Fahrenheit every eight hours. Providing your refrigerator is cold before starting your journey, you can keep things cool without needing to run the refrigerator. 

For best results, we recommend that you keep the refrigerator door closed and avoid opening it to keep the cold air inside. Any time the door is open and warm air hits the refrigerator, it can raise the temperature and if your refrigerator is off, it won’t be able to cool itself down. 

While you can probably drive your RV with your refrigerator on and have no issues, we recommend that you turn off your propane before entering a gas station. You don’t need us to tell you that open flames and fuel are a bad idea! 

If you are traveling on a ferry it’s worth checking their policies. Most ferries will instruct you to turn your propane tanks off before boarding to reduce any risks that can be caused by an open flame. 

How Much Propane Does It Use?

So how much propane does an RV refrigerator use? Well, thanks to how efficient these refrigerators tend to be, they don’t need much propane at all! The absorption process in your refrigerator is in a closed-loop, meaning you need little propane to heat the ammonia. 

While this is wonderful news, it’s worth noting that the amount of propane needed will vary from model to model. Smaller fridges tend to use less fuel compared to larger ones primarily due to their size, making them more efficient.

But these smaller units aren’t the most practical in larger RVs or for those that travel with a lot of food and beverages, such as on longer trips. 

If you are swapping your RV fridge, then we recommend purchasing a newer model as these tend to be more efficient than older propane RV fridges. 

Generally speaking, RV fridges will probably consume 1lb of propane a day. We’ve based this on the average size of an RV fridge is 6 cubic feet. So how does 1lb a day compare to other appliances? Well, a standard BBQ tank needs 20lbs of propane!

That’s quite a difference, isn’t it?

When we spoke to RV owners with propane refrigerators, they stated that throughout one summer (roughly 40 days), their refrigerator used roughly 8 gallons of propane. For reference, that’s just over two BBQ tanks of propane.

That’s not bad at all, especially when you consider how much propane your BBQ uses in the summer! 


Frequently Asked Questions

Before you go, get your last-minute questions answered here! 

Do I Need Electricity To Run My Refrigerator On Propane?

Yes, even when your refrigerator is running on propane, there needs to be some electrical power too. This is needed to power the circuit board on the refrigerator.

While you could rely on house batteries to do this, if there are any issues with them, you will have issues running your refrigerator. 

Can I Swap My RV Fridge For A Mini-Refrigerator?

If you want to, you can swap your RV refrigerator for a standard mini-refrigerator. Swapping the absorption fridge to a mini compressor fridge is not too difficult, but you will need to run a new 120VAC plug. 

This ensures that there is sufficient airflow around the unit, as the manufacturer states. You can speak to the manufacturer directly for more information about this.

It is worth noting that if you swap your refrigerator for a mini-fridge, you will only be able to use it while plugged into a generator or shore power. 

Final Thoughts 

And there you have it, an RV fridge works with a chemical reaction using hydrogen, ammonia, and water, along with some absorption! It isn’t as complicated as you once thought and there are many ways that you can help to keep the refrigerator cool too. 

Remember to only store cool items and to keep the area of the RV where the fridge is shaded where possible to reduce its workload. Providing that you use some of the tips we have suggested, you can keep your RV fridge running and cool with ease!

Madeline Cooper