Absorption vs compressor fridges?
There are two main types of rv or motorhome fridge, absorption and compressor. They function using very different technologies to achieve the same result. Each system has its positives and negatives which we will go into to make sure you make the right choice for your vehicle and available energy sources.
Aborption fridges are often reffered to as 3 way fridges, as they are capable of running of 240v, 12v and gas. They are commonly fitted to motorhomes and caravans so if you are replacing a refrigerator in a caravan or motorhome it is likely that it is an absorption style fridge.
How do absorption fridges work?
Absorption fridges work by using a priciple call evaporative cooling. The cooling system of the fridge is filled with hydrogen, ammonia and water. The water and ammonia in a liquid state are heated in the boiler, which is run by electricity or gas from the rv or caravan. As it is heated it seperates into hot ammonia vapour and liquid ammonia.
The vapourised ammonia is directed to an evaporator unit inside the fridge where it combines with the hydrogen gas. This mixture extracts heat from the fridge and reduces the temperature inside. Once the ammonia has done its job it is fed into the absorber where it is aborbed by the water. The water now contains ammonia again and by gravity it feeds back into the boiler to repeat the process.
Pros and cons of an aborption refridgerator
- Flexibilty - It can run from 240v (shore power), 12v and gas energy supplies
- Very quiet
- Energy inefficient (on 240v and 12v supplies) compared to modern compressor fridges which use around a 3rd of the amount of electric.
- Exspensive to buy compared to compressor fridges
- Need to be on a level surface to operate due to the gravity feeding on the bolier.
- Cooling capabilities drop in high temperature evironments
Compressor fridges only work from your electricty supply. They can utilise shore power in the form of AC power (240v), and DC power usually 12v and 24v from house batteries or solar system.
How do compressor refridgerators work?
Compressor fridges also work on evoprative cooling priciples however the way in which they do this is different.
Refridgerant is extracted from an evaporator and circulated by the compressor under pressure through cooling coils on the back of the unit. The pressur differences inside the system convert the refridgerant into a gas which extracts the heat from the fridge or freezer compartments. It then releases this heat through fins and and the process is repeated.
Pros and cons of a compressor fridge
- Efficient, they use approx 3-6 amps depending on the size of the fridge
- Do not need to be on a level surface to work
- Generally cheaper to buy
- the cooling potential is not effected by exterior tempretures
- Cannot run on gas
- Can be noisier although modern compressor fridges usually have a 'quiet mode'
If you are still not sure which type of fridge you need please call us on 0800 303 306 and one of our experts will be able to help.
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