Propane is the driving force behind an RVer’s lifestyle. Without it, everything is wholly dependent on electricity. In many cases, it may be the only source of power that you have. Thankfully, it’s an abundant and clean source of energy to fuel your appliances. When it comes to preserving your food, how much propane does an RV fridge use?
The standard, 20lb propane tank, of which most people are familiar, will hold 4.6 gallons of propane. The standard RV fridge is around 8 cubic feet and requires 1,500 BTUs to run for one hour. A 20lb propane tank will run this type of fridge for 280.6 hours.
That’s a long time to run a fridge for a standard propane tank, but the thing is, a single gallon of propane is worth over 91,000BTUs. Since it holds 4.6 gallons of propane, the math puts it at 280+ hours of refrigerator running time.
Of course, if you have a fridge that’s half the size, you’re looking at half the consumption and double the amount of time. As it turns out, propane is a pretty efficient fuel source.
Note: If you don’t know how to hook up an external propane tank to your RV, click here.
How does propane cool an RV fridge?
When you think of propane in the context of camping out, it’s almost always a tool for burning, whether it’s used for space heaters, burners for outside grilling, or a propane stove inside the RV. It’s never really thought of as a fuel that cools things off, especially to the level of a refrigerator.
A man by the name of Michael Faraday discovered a unique combination of elements called absorption cooling way back in 1824. It all boils (pun intended) down to a sealed system that is filled with pressure and chemical reactions.
This sealed system, which is a part of the propane-powered refrigerator, contains three things: ammonia, water, and hydrogen gas. The propane provides fuel for a flame, which makes sense because it’s propane. This flame flash boils the mixture of water and ammonia.
The fridge has a condenser and an evaporator, which play a large role in the process. As the boiling water and ammonia evaporate into gas, it flows upwards into the condenser where it is rapidly cooled before flowing into the evaporator that is waiting for it with the next element in the cocktail, hydrogen gas.
The hydrogen and liquid inflow mix and suck the heat out of the refrigerator, rapidly cooling the inside. This rapid cooling returns the ammonia to a gaseous state where it flows back into the beginning of the system, along with the water, to start all over again in one, endless cycle.
It’s an ingenious system and it’s also incredibly energy efficient since you can run it for several days off of a 20lb propane tank. With an even larger propane tank, the longevity becomes quite the luxury, unless you hate carrying around large propane tanks every time you hop in the RV.
Always remember that every gallon of propane is equal to 91,000BTUs and every additional cubic foot of space is equivalent to an increase of 187BTUs. This way, you will always have a general understanding of how much your propane fridge will require and how long the propane will last.
How to properly maintain your fridge in your RV
Fortunately, there is no shelf life when it comes to propane, so you can store tanks of it for years, with plenty of the stuff laying around for you to run your appliances. There is a twelve-year shelf life on the tanks that hold the propane, but so long as you keep up with the labels on the tank and get them recertified on time, it shouldn’t be a problem.
There are several ways to increase the efficiency and longevity of your propane and fridge combination so that both will last you for years to come:
- Establish a routine maintenance schedule
- Ensure that the refrigerator has good ventilation
- Always make sure that your fridge is level
- Clean off the back of the fridge routinely
- Ensure that there is plenty of space between the fridge and the wall
- Stock it only after you’ve run it first
One of the first “life lessons” you learn when owning an RV, is preventative maintenance is everything. That’s because lessons are hard-learned when far away from home and options are limited.
You want to establish a solid routine maintenance procedure that you stick to throughout the years. That includes cleaning the back of your fridge with regularity, say, once per week. The back of the fridge is where the majority of the heat dissipates and you will need to keep it clean and dust-free.
Dust builds up quickly in small spaces, especially if you are traveling with a large group. If it builds up enough, it serves as a sort of insulation on the back of your fridge, sealing in the heat that is meant to radiate away from the fridge.
When it comes time to stock up on food supplies, always run the fridge first and make sure it is good and cold before you start throwing food in there, that way the food doesn’t spoil waiting for the fridge to struggle trying to cool down.
Since the chemical reactions and the flow of the gases require a level surface, you should always endeavor to make sure that the fridge stays level, including when you park the RV. You never want to camp on a ridiculous incline.
Since the heat radiates from the back, make sure that the fridge isn’t squished up against the wall. Allow for some space back there and remember, the bigger the fridge, the more space you should give it.
Lastly, you can provide plenty of ventilation for your fridge by purchasing a fan that mounts onto the back of the fridge. The fan will expedite the heat’s removal from the area around the back of the fridge, maintaining its efficiency and possibly increasing the fridge’s longevity.
Propane fridge maintenance
There are several mechanisms that have to be 100% effective to get the most out of your propane fridge and you should do some routine preventative maintenance to keep them all in check. This is especially true if you plan on using your propane fridge for many years to come.
The flue and the flue baffle have the inconvenient habit of collecting carbon deposits. These deposits are slow to build up but over time, can seriously slow down the efficiency of the fridge. It’s quite the job getting them clean and you’ll need to remove the exterior paneling around the vent to access them.
Bring a ¾” wire brush along for the ride. It will be more than enough to break the carbon deposits off and scour the baffle clean.
The LP gas burner will need to be broken down to the smallest parts and cleaned as well. That ¾” wire brush will come in handy here as well and you should keep it with you for all of the various metal parts that need to be cleaned.
This includes the ignitor assembly, which is also prone to carbon build-up and deposits over several months of use. The condenser fins and the cooling unit itself don’t require anything more than a vacuum or a light blow with some compressed air. You don’t want to apply too much elbow grease to these, as it could cause irreparable damage.
The only thing that you will need to deal with on the propane side of things is the regulator and ensuring that the tank is recertified when the time rolls around. Propane tanks in the US last 12 years from the date of manufacture and ten years if they were made in Canada.
You can always check the dates on the top of the propane tank, as they are usually stamped into the ring/handles at the top.
How to cool your RV fridge without using a lot of propane
We’ve mentioned some things in the above paragraphs that will increase longevity, such as keeping the fridge off of the wall and installing a rear, battery-powered fan. Those things are great for week-long vacations, however, if you’re planning on going off the grid for a while, consider purchasing a cooler as well.
Ice is cheap and you can keep a cooler stocked for a long time. Keep your essentials in there and it decreases the number of times you have to open the fridge door. If you have any solar generators that you like to use, add an electric cooler to the mix as well.
When it’s really cold outside, you can adjust the internal temperature of the fridge to compensate, saving you on some propane usage over time. There are a hundred little things that you can do to become more energy-efficient, many of which you will pick up along the way.
With a propane fridge, your 20lb tank will last a long time without needing a refill, even longer the larger your tank and the smaller your refrigerator. There are also many things you can do to extend its longevity and efficiency.
If you’re considering installing a propane fridge in your RV, it will make an excellent and economical use for your propane stock. If you enjoy the efficiency and off-the-grid features that propane-powered appliances have to offer, you should certainly consider making the leap.