26 Apr Fridges – 3 Way or DC?
DC, 3 Way, Compressor, Thermoelectric…. Fridges – So many options, which one do I choose? In this blog I will explain the differences between all the options and help you decide on the best option for your needs.
DC (12V or 24v)
Not to be confused with an absorption fridge running in 12v mode. Modern DC fridges are very efficient and run solely off your house batteries. When connected to 240v your charger will replace the fridge draw, when not connected to 240v adequate solar is needed to replace the usage. These operate in the same way as your fridge at home. Most of all on the whole, compressor fridge’s perform better than the thermoelectric or absorption ones. Compressor fridges can reduce the temperature quickly and to around 50 degC below ambient. Hence they stay cold under a wide range of ambient temperatures.
Most DC fridges can run up to 30 degrees out of level.
With a correctly setup solar/battery setup the usage cost is essentially free.
Require adequate solar/battery capacities.
3 Way (Absorption)
3 Way fridges are referred to as such because they can run on 3 modes; 230V, 12V and Gas. This style of fridge has been around for many years and is found in most older motorhomes and caravans; it doesn’t have a motor but rather relies on the cooling effect of a liquid (in this case ammonia) when it evaporates into a gas. For this it needs to be level, have a well ventilated condenser plate and to have a heat source. The heat source can be from a heating element powered by 12V or 230V or from a gas flame. Being able to use gas as the power source makes it handy if you aren’t connected to 240v or you have a limited solar capacity.
Silent operation – as there is no motor/compressor there is no noise.
Can be run off LPG
Most cannot run when out of level by a few degrees
Need to be regularly serviced
Very power hungry in 12V mode
Conclusion: If you are building a new motorhome or caravan or are upgrading then go for a DC fridge, just be sure to size you’re solar and batteries correctly. Have a read of our blog here on solar and battery sizing.
But wait there is one more option………
A thermoelectric fridge produces heat or cold at a junction of dissimilar metal conductors where a current is flowing. They’re really designed as short-term coolers or warmers Thanks to their low weight, thermoelectric fridges are particularly easy to carry and transport Their cooling ability is limited up to 30 deg below ambient) but this is usually sufficient for most road trips. Their down side is the substantial drain on the car battery (almost 5 amps) – You’ll need to disconnect them when you turn off your engine. They can cool up to 30 deg below ambient temperature, noisier than other types of fridges but are the cheapest of all the models we have talked about.
Our range of fridges can be found here