Fridges come in all shapes and sizes to suit both the location and environment they are to be used in. Most of us are familiar with the standard domestic (kitchen) 230 volt compressor fridge we all keep our milk in.

But even with the huge variety of shapes and sizes there are only two basic types of fridge available to the mobile leisure market. The Absorption Fridge and the Compressor Fridge, they both have their advantages & disadvantages. (Cool boxes are not commonly regarded as true fridges because their cooling effect is dependent on ambient temperature, their workings are explained in their own section.)

Absorption fridges use a cooling process which is almost completely silent, very reliable, low cost and very effective. Their one big drawback is that, when run on electricity, they consume a massive amount of power - 8 amps/hour on 12V even for a small portable unit. This high consumption is the reason why most absorption fridges can also run on gas and mains. When operated with gas, absorption fridges are very economical to run and are perfect for use in situations where electricity is not available. Another potential disadvantage of absorption fridges which should be noted, is that, they must be kept almost level in order to work correctly. Different models have different requirements but, in general, 5° of tilt is the maximum that should be aimed for.

Compressor fridges work in just the same way as domestic models. A small DC compressor pumps coolant into an evaporator plate and down goes the temperature. Modern compressor-type fridges are so economical on DC power that they are increasingly to be found in motor homes and other vehicles as well as large boats where they have long been popular. Compressor fridges are unbeatable in terms of cooling efficiency, can be used without regard to angle of tilt and are so quiet that they simply cannot be noticed in normal circumstances. However, although a fridge of this type can consume as little as 1 amp/hour under average conditions, it will still be using well over 20 amps per day. Larger models will use considerably more power and, if the ambient temperature is high or if the fridge is being kept down to an internal temperature of -15C° for example, consumption may reach 4 amps/hour or more depending on the model. However, in the near future, compressor fridges should become available which use less than 1/4 amp/hour and then this type of fridge will become a practical possibility for most applications.