How a 3-way caravan fridge works

Share this article
caravan fridge

If we were to name five essential appliances necessary for caravanning and camping, unflinching one of them would be a fridge. Because food safety and freshness are crucial factors for your holiday’s success, you can never overlook the importance of a caravan fridge.

The 3-way fridge is the camper’s favorite

It is easy to see why the 3-way camping fridge is what most campers prefer. It is very flexible and can run off alternating current using battery equipment, cooking gas, and direct current accumulated photovoltaic batteries. Absorption refrigerators like 3-way fridges can switch over to propane if there is any need to conserve energy.

The working of a 3-way fridge

The 3-way fridge works on the Absorption principle. It works on the Law of Partial Pressures by Dalton. The absorption refrigerator needs the application of heat for it to start working.

That is how it has got its name from. The three different ways of providing it the necessary heat to start operation are:

  1. Using a small heating element of 12volts.
  2. Another heating element of 240volts
  3. A small gas flame.

Apart from these three, a fourth absorption system is also present that is fully-sealed. The standard size of the fridge is about 35-40 liters.

Difference between 3-way fridge and compressor fridge

The 3-way fridge does not have compressors to cool the unit. The cooling comes from an exchange flow of gases that happens at the back of the fridge.

The best example of a compressor fridge is the fridge that we all have at home, the RV fridges also known as the 2-way fridges can run on either a 12 or 24 volt battery or run on 240-volts power from the generator set.

The 3-way fridge is a classic example of an absorption fridge. Unlike the 2-way fridge that uses a compressor to cool down, the absorption fridge needs to remove all the heat from behind it in order to be able to create the cold.

There will be a minimum load of 6.25 amps if any of the heating elements are being used. If gas is used to power the fridge, the user will have to use it for about one kilogram that will last approximately a week or ten days.

The three heating systems are not used simultaneously. If you worry about any fault in the absorption system, let us assure you that it will not fail unless you physically hurtle and damage it. You must ensure that it is well in place when you are navigating difficult terrains because it is not repairable.

The refrigerant used for cooling in a 3-way fridge is ammonia. The water and hydrogen cycle the ammonia.

Main components of the fridge

  • The Generator that generates ammonia is in gas form
  • The Separator that separates the ammonia gas from water
  • The Condenser where the very hot ammonia gas gets cooled and gets condensed to get back to liquid ammonia form
  • The Evaporator where liquid ammonia evaporates and in the process removes heat from inside the cabinet.
  • Absorber where the water absorbs ammonia gas.

Positives of 3 way fridge

  • The fridge is economical to run since it can be a week on an LPG standard 9 liters cylinder for weeks together
  • There is no need to invest a lot battery equipment
  • It is very quiet, unlike the noisy compressor fridges
  • The fridge needs very little maintenance and that is why it is preferred over the other kinds

Negatives of the 3-way fridge

  • Because the cooling in the 3 way fridge happens due to gas flow, it needs to remain at the same level all times. This may not be the case with a fridge if you are planning to navigate on rocky terrain.
  • The 3-way fridge needs storage in place with excellent ventilation because it runs on gas, and storing it in a closed and tight place will overheat it and prove dangerous.
  • 3-way refrigerators guzzle up all the battery and quickly
  • 3-way fridge takes 5 to 10 hours to cool down when you kick-start it. It is recommended that you turn it on from the night before you are planning to set out.
  • 3-way fridge takes 5 to 10 hours to cool down when you kick-start it. It is recommended that you turn it on from the night before you are planning to set out.
  • Compressor fridges are usually not affected by the ambient temperature outside the camper. But a 3-way refrigerator is not like that. He is generally affected by the outside temperature, and therefore its cooling can slow down if the outside temperature is very hot.


Like we said, until they are physically hurtled, the three-way refrigerator does not need routine maintenance at all. They can last as long as 20 years! Go for a branded 3-way fridge because then they are better designed to handle the bumps of the rugged roads and the harsh Australian sun. Replacing the fridge once in 20 years means almost double the time of your compressor fridges.

Andy Sullivan

Andy Sullivan

A lover of all things outdoors, Andy is an experience camper having traveled the east cost of Australia multiple times and countless trips throughout New Zealand.

Leave a Reply

Recent Posts

Follow Us

Keep up to date with everything camping related, from new gear and equipment to the best places to camp around Australia!

Weekly Video

Sign up for our Newsletter

Get the latest camping and 4WD news delivered to your inbox.

How we make money is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Additionally, participates in various other affiliate programs, and we sometimes get a commission through purchases made through our links.

Omg... what a great deal!

bigwig jerky