You’re probably reading this post because you’re looking to replace the existing refrigerator inside your RV. A lot of people just tend to use whatever refrigerator comes with their RV unit, but what if it goes permanently broke or isn’t really big enough for your needs?
Even if you’re not looking to buy an RV refrigerator right away, it is quite important to know how your existing one works.
As a general rule, this goes for all appliances inside your RV. Having a general understanding of all of them will help you do at least some basic troubleshooting when something goes bust, and save you money you’d otherwise spend on hiring a professional to come take a look.
So, how do RV refrigerators work?
RV refrigerators are usually run on propane gas, but the principle of refrigeration is the same, regardless of the type of fridge. Basically, a coolant(ammonia) is boiled into a gas and then condensed back to liquid form. This process continues in a cyclic manner and gives off a cooling effect which provides the refrigeration. The official name for this type of refrigerator is called a gas absorption refrigerator.
We’ll look at this process in more detail later in the article.
While there are many different types of RV refrigerators such as electrical, propane, battery operated, and so on- essentially, the only difference in working is how the refrigerant gas is heated.
Let’s look at the types of RV Refrigerators in detail.
RV Refrigerator Type #1: Propane Refrigerators
Propane fridges(also called gas absorption refrigerators) are the most popular with RV owners because of their convenience and sheer economy of use.
The use of the word propane could be a little confusing… propane is used to HEAT the refrigerant and is the primary “go to” for RV refrigerators which are primarily gas absorption refrigerators.
These RV refrigerators are different from standard home refrigerators because they don't have a compressor or any other moving parts. The liquid circulation happens purely by gravity, pressure, and the phase state change (a complex series of words from 8th grade physics).
If you've never seen one before, a propane refrigerator is easily identifiable by metallic fins (also called a heat exchanger) at the back- that you can see as you open the door.
These vents are responsible for removing the heat from the refrigerator. An extremely hard idea to wrap your mind around: Refrigerators don't put cold INTO the fridge, but instead the remove heat from the inside of the fridge. Yes, the “fins” in the fridge are cold, but the heat in the fridge warms them and the coolant flow scootches the warmer coolant back into the pool to be recycled again.
Propane fridges have a burner at the back which provides an open flame when the fridge is on. This is what provides the heat to the refrigeration system. This heat evaporates the coolant. Eventually when the coolant changes from gas back to liquid – this is when the “cold” occurs.
Apart from that, propane fridges also have a venting system at the back that allows heat generated in the refrigeration cycle to be dissipated outside of the RV.
Process wise- a propane fridge works in the following manner:
- An open flame burns at the back of the fridge to provide heat
- This flame is used to heat up a solution of ammonia ( the coolant) and water, which boils up into a gas
- The gas travels upwards through pipes into the condenser area where it condenses into liquid form
- Liquid ammonia now travels to the evaporator chamber, where it mixes with hydrogen and evaporates. This process removes heat from the evaporator space, which provides a cooling effect inside the fridge.
- The ammonia-hydrogen mixture flows to the absorber where ammonia separates out to form a liquid solution with water again.
- The hydrogen gas flows back to the evaporator chamber.
- Steps 1-5 go on continuously for continued refrigeration
By contrast, a standard electric refrigerator uses electricity to run a compressor that compresses a coolant. Compressed coolant gets very cold. Apart from that, the principle of functioning between any refrigerator type, as I said earlier, is the same. It is the same in that the ideas around pressure and phase state changes you learned in high school are applied to cool the insides of a refrigerator.
An important concern for a lot of people with propane refrigerators, is driving with their propane fridge switched on- which essentially means driving around with an open flame.
Here’s a potential scenario:
An RV with a propane fridge switched on gets into an accident, and the pipes carrying the propane gas break- causing a leak, which in turn catches a spark and lights up the vehicle.
Now, this may seem like a long shot- and of course the odds of this happening are pretty low, but it does happen. It seems silly to take that kind of risk just to have your water ice cold.
However, there is a way out:
These days, a lot of ‘2- way’ or ‘3-way' RV refrigerator models have integrated electric functionality along with propane.
Basically, they can run either on your RV’s DC batteries OR on propane. With such a fridge, you can simply choose to run it on electricity while you're driving.
When it comes to economy of use, 2-way fridges are a bit less efficient on electricity than they are on propane- but they certainly won't be a drain on your batteries.
Advantages of a propane fridge
- Very efficient. A 40 pound propane cylinder can last two people about a month and a half when used for just cooking and refrigeration.
- Highly durable. On average, a propane refrigerator will last up to 20 years. However, I even came across a lot of forum posts online where people claimed 30 year lifespans for their propane fridges!
- Rugged. They can withstand the vibration of travel that is common with an RV.
- Doesn’t affect internal climate control. Heat generated in the refrigeration process is dissipated out of the RV.
Disadvantages of a propane fridge
- Need frequent maintenance- in fact, not doing so is a potential fire hazard. For instance, the burner area should be kept clean and out of contact of anything that might catch fire.
- Doesn't cool exactly as well as a compressor style refrigerator. It’s the difference between getting slightly soft ice cream and rock hard ice cream from the freezer
- The risk of driving around with an open flame OR
- Having to turn off the fridge while you're traveling can quite inconvenient for some. There are ways to work around it though, and I'll get to them later in this post(see the section on 6 maintenance tips below)
- Propane fridges are susceptible to outside temperatures and you may find your cooling goes down a notch inside the fridge when it’s hot outside. On the flip side, it may cool more than you’d want when it’s chilly outdoors, so it won’t always work EXACTLY as you’d like.
The Most Important Maintenance Tip For Your Propane RV Fridge
Your propane RV fridge needs to sit level on the floor of the RV. This is because, unlike compressor based fridges, the refrigerant liquid is gravity fed.
So, if the floor is sloping, then the coolant is bound to accumulate in a few places inside the pipes and won't be able to flow effectively. This will in turn, lead to reduced refrigeration and can even cause damage to the fridge if not corrected soon.
To ensure this doesn’t happen, here’s a handy pre installation tip:
Get a low cost level and place it on the floor where you’re planning on installing the fridge. If it’s level, you’re good to go- and if not- at least you know you need to make some modifications.
RV Refrigerator Type #2: Standard Home Refrigerators
Standard home refrigerators are the second most popular choice among RV owners, after the propane-electric models. The only difference is they have moving parts such as a compressor unit, and rely on AC current for operation.
Still, installing a compressor based fridge in your RV is only feasible when:
- You have a big enough RV
- You can invest on batteries
Let’s break it down:
Home refrigerators are much bigger than refrigerators specifically made for RV’s. This is why you’ll need some additional space, which is hard to get in small RV’s, unless you are okay with potentially having to make some modifications indoors.
This is why one of the first things you should do, if you are considering a standard home refrigerator, is to assess the space inside your RV.
A bit of planning doesn’t hurt here, so go look up the dimensions of the refrigerator online and, with a measuring tape, map out the exact dimensions of the space inside your RV where it would go.
If you realise you don't have enough space, then the next option is to think about making some modifications to the interiors.
For instance, you could probably make some room for your refrigerator by cutting down on the adjoining cabinet spaces.
Secondly, don't forget to measure your door, in order to see if your refrigerator can easily pass through it or not.
Now, as for the point about batteries:
A standard home refrigerator will definitely be quite a heavy load on your RV. Also, the conversion of DC current from your batteries to AC using an inverter leads to additional wasted power.
Now, of course, if you have a smaller home refrigerator than the one used in the test, you might end up getting a little more use out of it- but nothing that’ll be significant.
Realistically speaking, you’ll probably end up having to run your generator everyday for at least a couple of hours.
This is why the best solution is to invest in upgrading the standard batteries in your RV to allow for the increased power usage. You can also think about installing solar panels for near continuous power supply, if you live in a sunny area like California.
Advantages of Standard Home Refrigerators For Your RV
The biggest advantage is that it will give more space and you can have a fully stocked fridge at all times. If you’re travelling with kids, this can make or break your trip!
It’ll also be lower upfront investment. On average, a standard home refrigerator costs half as much as a specialised RV refrigerator.
Disadvantages of Standard Home Refrigerators For RV’s
Heavy power usage means that you’ll end up having to invest on batteries/ solar panels/generator for your RV
Since they contain multiple moving parts, the constant vibrations due to being on the road, increase the chances of something or the other going bust. There’s a reason why RV fridges have no moving parts!
Home refrigerators are also made of soft metals like aluminium, brass and copper. These aren’t as durable as steel, which is what RV fridges are usually made of.
Lastly, they also pose an issue in temperature control inside the RV, since they reject the heat back inside the RV- unless you make some modifications and add a custom vent leading the heat outside.
But What If You Really Want A Standard Fridge For Your RV?
If you really want a standard fridge for your RV, you need to find a way to ensure longevity.
What I mean is, you need to find a way to reduce the vibrations on the RV floor that come from being on the road constantly.
One potential solution could be to install a vibration damping material in the floor underneath your refrigerator.
is one of the best products that you could buy for this. Typically it's used for soundproofing car interiors due to the material’s ability to stop sound transmission from vibrations. But it could be used just as well for a vibration dampening material.
RV Refrigerator Type #3: 2 Way And 3 Way RV Fridges
2 way and 3 way fridges are, hands down, the most convenient of all the categories!
The 2 way fridges are gas absorption type propane refrigerators. 2 way fridges, simply are those that can run on:
- Propane and DC electricity(less common)
Apart from these two, there also is a third category of 2-way refrigerators that is similar to standard refrigerators, i.e: has a compressor.
RV Refrigerator Type #4: Solid State/ Thermoelectric Refrigerators
Probably the least popular option out there, solid state refrigerators are used more as chillers, than refrigerators, really.
On top of that, they are even more susceptible to the weather outside than propane fridges AND they only come in small sizes.
A solid state refrigerator consists of an n-p-n transistor. When current passes through it, one side of the transistor heats up while the other becomes cool.
Blowing a fan on it, the refrigerator routes the cold air to provide cooling and dispenses off the hot air outside.
I wouldn’t recommend a Thermoelectric fridge at all, unless you actually want a chiller for your RV. It would probably do just fine as a secondary refrigerator- but if it’s the ONLY RV refrigerator purchase you’re considering, steer clear!
6 Additional Tips For Getting Better Cooling Out Of Your RV Fridge
- As much as you can, try to park in shaded areas- away from direct sunlight. Cooler the outside temperature is, the better an RV fridge will function.
- If you are going to be switching off your propane fridge while driving, pack a few ice cold bottles of water inside the fridge before leaving and keep the door closed as much as possible. According to dometic, you can drive for about 8 hours without losing more than 4 degrees of temperature inside your refrigerator.
- Ensure that your door gasket is sealing properly. To check this, put a piece of paper between the doors and close it. If you are able to move the piece of paper around it means the gasket isn’t closing tightly and you should replace it.
- Plugging the fridge in the night before your trip is a good idea as it’ll take upto 6 hours to cool down properly.
- Adding to the above point, before your trip, you can also stick some ice in the refrigerator overnight – to speed up the cooldown process.
- For propane fridges especially: Get a refrigerator fan to ensure the cold air properly circulates inside. They’re quite cheap and will last up to 6 weeks on a pair of fresh batteries. I really like .
My Final Recommendation
Go for a 2 way, propane-electric refrigerator. They are the most convenient solution for someone who likes to do both- normal RV trips as well as boondocking.
I also like the fact that you can be completely safe while driving around in your RV- you can simply turn off the propane burner and put the fridge on electric mode.
As for residential refrigerators, they are mostly suited only for higher end RV’s with higher battery capacities and limited travel – like an RV Park Model.
Also- if you regularly plan on boondocking, I wouldn't recommend you get a residential fridge without doing the math first. You’ll need to be absolutely sure about your battery capacity and power usage.
That’s about it- hopefully, no RV traveller ever has to drink a lukewarm beer after reading this post!
Now I’ll hand it over to you:
What type of fridge do you have in your RV and how has it worked out for you? Jump into the comments and let me know!
To cold beers!
For more information, check out these RV52.com resources:
- RV Refrigerator
- RV Refrigerator Side Vent and Drain – Fifth Wheel Pictorial Guide – Exterior
- RV Refrigerator – How To Videos
Quick Search for 2-way Refrigerators: