Refrigeration

Most caravans are fitted with absorption type fridges that run on 12 volts, 240 volts or gas. These fridges are generally not as efficient as compressor type fridges such as Engel and Waeco as they are more susceptible to ambient temperature. Absorption fridges do have the advantage that whilst running on gas they require no electricity. So if your batteries have been depleted by several days of inclement weather with no solar input your fridge will still run.

The 90 litre three way absorption type fridge in our Goldstream Explorer does not function efficiently in high ambient temperatures. At 30C it starts to lose effectiveness and by the time the ambient temperature reaches 35C it is hovering around 10C. It is strange that you cannot buy an absorption type fridge under 120 litre that has a tropic rating. Maybe a tropic rated absorption fridge of  120 litres or over would handle the heat better but I cannot comment on this.

If you buy a caravan then the likelihood is that it will have an absorption type fridge and there are a few things that you can do to make sure they run as efficiently as possible:

  • Ensure that the fridge is mounted in accordance with the refrigeration manufacturers instructions. This is vitally important to ensure proper ventilation. Do not take anyone’s word for this, get a copy of the installation manual and check it yourself;
  • On 12 volts such fridges run constantly, they do not utilise a thermostat. They also draw large amounts of current. If you stop for several hours and do not switch to gas or 240 volt the chances are you will seriously deplete your battery. Fit a commercially made “fridge switch”. This device switches off the 12 volt supply if the van remains stationary for 3 minutes and switches it back on when the van moves. As a check you can also fit a LED near the fridge to show when 12 volt power is available to the fridge;
  • Fit a thermostatically or switch controlled (I prefer switch control) fan to blow air over the fridge cooling fins. This fan MUST be mounted so that it moves air from the lower vent over the fins and out the top vent. You may need to mount this on rubber mounts to stop any annoying noise. If you have dust excluders that fit to the fridge vents whilst on dusty roads (covered in another article) you need an isolating switch to turn this fan off when these are fitted. Once again fitting a LED to show power supply to the fan is a good safeguard;
  • In very hot conditions it may be necessary to remove both the top and lower fridge vents to enable better air circulation. If intending to do much travelling in such conditions it may be worthwhile to make these vents swing up so they can easily be opened;
  • Fit an awning track to the van roof above the fridge vents. You can then have a shade that slides into this track when needed and shades the fridge. This can make a considerable difference to the operation of the fridge, especially in the tropics if the van is orientated so that direct sunlight falls on the fridge side of the van (see attached photo) and;
  • Fit a remote temperature sensor so that you know your fridge’s capability and performance.

Fridge shade

Our 90 litre fridge is fed by two 4.5 kilogram gas bottles that each have a supply line and are changed over via a manual switch. If any gas bottles are carried in a potentially dusty environment they must have the inlet ports protected, hence two supply lines. We get approximately two weeks from a 4.5 kilo gas bottle but this is subject to water heater use, ambient temperature and other variables.

It is becoming increasingly difficult to have gas bottles filled. Most offer “swap and go” because to fill gas bottles government authorities now demand that the person filling the bottles holds a licence to do so. The problem with “swap and go” is the amount of gas that you get. Instead of 4.5 kilograms “swap and go” is 3.70 kilograms, 18% less! Such a difference can be important when you are travelling in remote areas.

I see many travellers carrying two or even three fridge/freezers, often one in the van and one in the car. This sometimes leads to such travellers always requiring 240 volt when they camp, whether from mains power or a generator. Is such capacity really necessary? In my opinion it is not. We can live very well for two weeks or more from what we have in our 90 litre fridge and stored dry goods.

Don’t over burden yourself with supplies and refrigeration capacity, you are just making problems for yourself. Remember the old adage “keep it simple”.

updated 19/11/2011

goldstream, goldstream explorer, goldstream caravan, off road caravan, outback travel
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