Wonder how you are supposed to go off the grid camping in your RV? Your adventures might bring you to a forest, desert, or some place without electricity especially nearby. These peaceful situations are where propane powered fridges really help.
But how does an RV fridge run on propane? How it is possible for a gas to either add cooling to a fridge or pull away heat? Propane fridges are technological marvels, but they are actually fairly simple.
A propane tank uses a combination of basic chemicals and liquids to pull heat from the fridge. The process to make this work is quite interesting and will be explained below.
Does a propane fridge actually cool or does it absorb heat?
Your household fridge works differently from a propane powered fridge. The household fridge uses coolant, a compressor, and a fan to push cold air into the enclosed spaces of the fridge. This uses electricity, of course, to power both the compressor and the fan.
A propane flame
Let’s start with the liquid that powers the process of cooling down your fridge. Propane is stored in a separate tank outside of our RV with lines running to the fridge and in some cases, hot water heater.
The propane fridge has an ignitor that turns the combustible gas into a flame. The flame is under a tank that combines water and ammonia to it’s boiling point, and is called the generator. This happens relatively quickly as a propane flame’s heat is nearly instant.
In another sealed chamber connected by tubes, we have a a condensing chamber which receives the gas produced by the combination of water and ammonia. The gas cools down within this chamber and returns to a liquid state.
The next step is for this liquid to move into another sealed chamber with hydrogen gas. The chemical reaction created by the liquid and gas combination starts to pull warmth from the fridge. Once the gas and liquid combo gets warm enough, the ammonia become gas again and the whole process starts over.
To answer the above question: propane fridges don’t force cool air into the fridge’s chambers. Instead, they use a series of chemical reactions to pull heat away, absorb it, and reverse the same reaction.
Do I run out of anything in a propane fridge?
You will run out of propane, but that’s to be expected for a combustible gas.
Otherwise, you should not expect to run out of ammonia, water, or hydrogen gas. The chemical reaction within the fridge is designed to return all the liquids within to their normal state.
That said, if you do start to “run out” of things, the issue could be with leaks rather than actually burning through hydrogen gas or ammonia. The seals within the tanks can gradually breakdown. Take a look at these once in a while to see if any of the seals are bubbling or starting to come apart.
Thankfully, the seals are relatively easy to replace compared to replacing parts in a typical fridge, which usually involves removing and replacing entire parts.
Are there any advantages to propane?
The process that makes a propane fridge cold can certainly be helpful for those who aren’t around electricity.
A propane fridge also doesn’t have many, if any moving parts since the entire process starts with a connection to a gas line. A propane fridge can last for a long time since it doesn’t have a motor and needs no electricity. The containers within are normally made of metal and can outlast the parts in a traditional fridge.
Propane fridges are also great if you are in a part of the country or world with frequent power outages. You won’t need to worry about moving all your cold foods to someplace else because so long as you have propane, you have no problem.
A propane fridge is also lighter and easier to move with just small tanks with liquid rather than large motorized parts.
Any disadvantages to propane?
Propane starts up faster, but is ultimately slower to cool than a traditional electric fridge. Why? It’s absorbing heat instead of pushing cold air in. You can get battery powered fans to potentially push warm air out faster.
Propane also needs refills. Many RVs have the ability or come with a dual propane tank holder that allows RV owners to carry multiple tanks with in case one runs out. Propane isn’t especially cheap, normally running $20-$25 for a 20lb container that will last around 11 days under normal circumstances.
If you have a fridge that runs both propane and electric, we suggest using electric when you can for more cost efficiency.
Is propane dangerous in an RV?
It can be. We certainly recommend shutting off propane lines while you drive around. If you get into an accident with flowing propane, the lines can break and small sparks can cause explosions.
If you do intend to drive around alot, just ensure that the fridge remains closed so that cooled air isn’t replaced by warm air. The propane can be turned right back on when you stop to keep the cooling process going.
Your water heater might also be powered by propane and the same conditions apply to your water heater.
Having propane powered appliances can involve a little more waiting than you are used to with electric, but are well worth it for serious camping and safety.
Propane fridges are both simple and technologically complex. Rather than relying on power from an outlet, they use a chemical reaction that is both safe and effective at removing heat from a contained area.
One of the most interesting parts of a propane fridge is it’s ability to use the same liquids and gasses over again without running out, and the ability to heat those liquids quickly. Propane fridges can get off to a fast start.
We hope you learned a bit amount about propane fridges and how they work.