Caravan refrigerators are most commonly the absorption type, the type that run on 240v, 12v and LPG, they are popular primarily because they can be used when camping away from a power point (on gas) rather than needing electricity and they can be operated from the tow vehicle battery while travelling. Compressor fridge's are becoming popular, improvements in compressor technology and batteries will some day see them replace the absorption fridge. In the meantime there are a few things you can do to ensure your absorption fridge is working at peak efficiency.
The main thing that can affect this type of fridge is ventilation, or lack of it...an absorption fridge will work best if the hot air that it generates is removed as quickly as possible...unfortunately few caravan manufactures design the fridge cabinet backing with this in mind, while the installation will probably suit most owners needs, especially those in Australia's south its not until we venture into the tropics that the deficiencies become apparent...our 2013 Jayco was such an example.
It is worth noting here that as well as the caravan fridge we have a Waeco portable freezer. This unit operates in a similar fashion to a home refrigerator with a compressor. Despite it remaining constantly on the back seat of the car where the temperature at one point was 42 celcius it had no difficulty in maintaining -14 to -17 degrees. The down-side to this type of unit is that it only runs on electricity (12-24vdc or 240vac), with one of these fridge's you must have access to electricity constantly.
Click on a photo below to see how I improved the operation of our caravan absorption fridge.