3 Way fridge
3 Way Fridges
A 3 way fridge can be powered by LPG gas, 12volt or 240volt power making it very reliable and convenient to keep your fridge running whilst on the road or caravanning in remote areas.
Put simply, a 3 way fridge is commonly referred to as a 'gas' fridge or 'absorbtion' fridge and operates a lot differently to your normal household 12 or 240 volt compressor type fridge, although acheives the same result in circulating the refrigerent to keep your fridge cool.
The advantage of a 3 way fridge is that it can run for weeks or sometimes months without the need for electricity, and it does this silently as the absorbtion method does not require a compressor to circulate the refrigerent gas.
If you would like to talk to a caravan fridge expert, who can help with sizing and installation requirements and will be happy to organise the fridge to suit your needs - feel free to call us on 1800 787 278
3 way fridge FAQ's - Whats the difference between a 3 way and a normal compressor fridge?
All fridges require refrigerent gas to be circulated in different states (gas and liquid) around the inner workings to create a temperature difference and direct the cooler air to your fridge or freezer compartments. To circulate this refrigerent you can simply use a compressor which will require 12v or 240 volt power and physically pump the refrigerent gas around the system, or you can use absorption method which basically means you are heating the liquid refrigerent allowing it to turn to gas and essentially float around the system untill it is cooled back to a liquid returng to tank - either way the name of the game is to get your refrigerent to change from a liquid to gas to enable circulation around the system. It is the changing of state from liquid to gas that creates the temperature difference of the surrounding air which is then harnessed to the cooler compartments of your fridge or freezer.
Most 3 way fridges operate on an absorption style principal, the 3 way absorption refrigerator requires the delivery of heat to start the fridge operating. Daltons law of partial pressures is the foundational operating principal of absorption type refrigerating systems. This is how and where the name 3 - way derived from, three ways of providing the application of heat. Firstly, is your 12-volt supplied off your house batteries or whilst towing the battery from your vehicle.
Second, is your 240-volt power supply whether it be a direct 240-volt power supply from a camp site, residential housing, or from a backup generator also using an appropriate heating element. Last but not least is you Lpg gas supply delivering you the option to have a chilled fridge almost at any given time whilst upon your travels using a small gas flame. These refrigerators are designed with what is commonly known as a furnace. It can be identified at the rear of the fridge and is insulated to hold the heat in and has a small flu (exhaust) from the top.
How Does It Work:
The 3-way construction uses ammonia as their refrigerant, combining water and hydrogen to continuously cycle the ammonia. The 3-way refrigerator has five main components:
- Absorber - The main purpose of the absorber is to absorb the ammonia gas.
- Condenser - Is where the hot ammonia gas is cooled and condensed to create liquid ammonia.
- Evaporator - Where the liquid ammonia evaporates removing heat inside the cabinet.
- Generator - Generating ammonia gas.
- Separator - Does the job of separating the ammonia gas from the water.
The basic function of the 3-way fridge is that heat is delivered to the generator by one of the three heating systems. In the generator is a mix of water and ammonia, the heat raises the temperature of the mix until it is boiled. Once the boiled mix climbs to the separator the water is then separated from the ammonia gas. The ammonia gas then flows upwards to the condenser. The condenser incorporates metal coils with fins that allow the ammonia gas to dissipate its heat and condense to form liquid ammonia. The liquid ammonia makes its way to the evaporator, where it mixes with hydrogen and evaporates removing heat from inside the refrigerator cabinet. Then the combined mixtures of ammonia and hydrogen gases flow to the absorber. Here, is where the water that has travelled from the separator is mixed with the ammonia and hydrogen mixture ammonia readily mixes with water and returns to the generator while the hydrogen does not mix, so it is separated for return to the evaporator and so the cycle continues as long as heat is provided to the furnace.
Keeping the 3-way refrigerator level is one of the most important procedures of running theses type of fridges. When the appliance is not level the combining liquids do not circulate correctly there for causing the cycle to stop.
What Are the Advantages:
- Quiet and efficient operation
- Availability of 240 volt, 12 volt and gas
- Avoiding the use of moving parts
- Easy to maintain
- No need to start your vehicle to power your fridge when operating on gas
What Are the Disadvantages:
- Unable to operate unable to operate correctly on un even grounds
- Draws high current on 12-volt applications
- Ventilation is required to an outside portal
- In elevated temperature climates may struggle to effectively cool down
- Make sure there is adequate ventilation through an external portal and fridge surroundings
- Be sure to use the correct size wiring on installation, most commonly used is 6mm twin sheath
- Check the dimensions of your fridge before purchasing the appliance to save on installation fees as it can get quite costly to re design internal surroundings and cabinetry.
Get the help you need to make any trip the best it can be with Caravan RV Camping’s huge range of tools, parts and systems. Suitable for boats, motorhomes and caravans of all sizes and models, we hand select every product we sell to ensure that our customers are only getting the best, most useful units available on the market.
With competitive prices, fast nation-wide delivery and a dedication to providing quality customer service and after-sale support, you can rely on us for a smooth shopping experience. Browse our range of products from fridges to solar panels from reputable manufacturers such as Dometic, Vitrifrigo and John Guest.