LPG Absorption vs DC Compressor in Detail
Here’s another question we get asked often. Absorption or Compressor?
Even though there are 3 ways to power a fridge (LPG, 240V AC, 12/24/V DC), there are only 2 main types of low-power cooling systems, Absorption and Compressor.
Absorption Fridges perform their best when they are operated on LPG or 240V in a stable and level situation, like in a house, cabin, farm or camp site. The benefit of an LPG fridge is you only need to invest in a bottle of gas and you are up and running for weeks or months at a time - so the up-front costs are minimal.
Compressor Fridges are the best all-rounders as they are suited to all environments. They will perform better in extremely hot and humid conditions or when a stable and level surface is not available, like in a 4WD, truck, caravan or boat. To run your compressor fridge, you will need a stable 12 V or 24 V power supply, mostly likely from a car battery or bank of batteries. Also, DC fridges don't require any ongoing maintenance, whereas your Absorption cooling system needs a clean once or twice a year.
A compressor fridge uses electricity to run a low-power compressor, which in turn pumps the refrigerant through the cooling system.
DC fridges use a dedicated 12V / 24V compressor which is designed to operate in a moving vehicle.
We use Secop Danfoss branded compressors which will operate on angles up to 30º.
In general terms, a compressor fridge will also perform better in extremely hot and humid conditions.
This combination makes compressor fridges the first choice for mobile use or off-grid situations where 12 V power is readily available.
A stable dc power supply is generally provided by a car battery or bank of batteries. Your batteries will need to by topped up regularly. You can do this is a variety of ways; using your car engine, boat engine, solar panels, a petrol/diesel generator, a 240V smart charger or any combination of these.
An absorption fridge uses heat to move the refrigerant through the cooling system.
LPG is the most efficient way to run an absorption fridge, as the LPG can instantly produce a very hot flame.
240 V power will also cool an absorption fridge well, although the heating element needs to produce the same amount of heat as a gas flame, so it is not as efficient as on LPG.
12 V operation in an absorption fridge is often considered a holding mode only. The temperature of the fridge will remain steady, but the fridge will not have the power to cool down quickly. This occurs because the small 12 Volt heating element cannot produce the same amount of heat as a gas flame, so it uses alot of electricity trying to keep up. The XD70 is the only 3-way chest fridge we sell. Most of our customers use it for long stints in the one place - like setting up camp for a couple of weeks at a time or for a more permanent off-grid situation.
A stable, level surface is required to operate an absorption fridge in the most effective way. So a moving car, caravan, motorhome or boat is not an ideal situation. For all mobile refrigeration needs, we strongly recommend considering a DC compressor fridge.
2-Way and 3-Way are terms referring to absorption fridges which can operate on 2 or 3 different power supplies. This is usually a combination of LPG and 240 volt (2-way) or LPG, 12 volt and 240 volt (3-way).
Absorption fridges are best used mostly on LPG and in a stable situation. They have a very low up-front cost – just a bottle of gas.
DC compressor fridges work better in mobile situations or when a stable DC power supply is readily available. The up-front costs are higher; batteries and either solar panels, a generator, or a smart charger. But after that you are up and running for years.
Check out our Fridges to find the best portable fridge for you.