Compressor vs. 3-Way Fridge

Compressor vs. 3-Way Fridge

Choosing the Right Refrigeration Solution for Your Needs

When it comes to keeping your food and beverages cold on the road or in off-grid locations, two popular options are compressors and 3-way fridges. Each has its own set of advantages and disadvantages, making the choice between them a crucial decision for campers, RV enthusiasts, and outdoor adventurers. In this blog post, we will explore the key differences, advantages, and frequently asked questions about compressor fridges and 3-way fridges to help you make an informed decision.

Compressor vs. 3-Way Fridge

What’s the difference between a compressor and a 3way fridge in a caravan

A caravan fridge is essential for keeping your food and beverages fresh during your travels. Two common types of fridges found in caravans are compressor fridges and 3-way fridges. Here’s a breakdown of their differences, as well as the pros and cons of each:

Compressor Fridge (2-way fridge):

  • How it works: It uses a compressor and a refrigerant gas system similar to the fridge in your home.
  • Power source: Runs on 12V/24V battery power and can also run on 240V mains power.


  1. Efficient Cooling: Cools down quickly and maintains temperature efficiently.
  2. Less affected by ambient temperature: Can maintain internal temperature more consistently regardless of outside temperature.
  3. Lower maintenance: Generally, fewer parts to go wrong than with 3-way fridges.


  1. Power consumption: Consumes more power than a 3-way fridge when not connected to mains power.
  2. Cost: Typically more expensive than 3-way fridges.
  3. Noise: The compressor can be noisier than the silent operation of a 3-way fridge.

3-Way Fridge (Absorption fridge):

  • How it works: It uses a heating element to circulate a refrigerant through an absorption system.
  • Power source: Can run on 12V battery power, 240V mains power, or LPG gas.


  1. Versatility: Can run on three different power sources which is great for off-grid situations where battery power might be limited.
  2. Quiet operation: Almost silent when running on gas.
  3. Energy efficient on gas: Consumes little gas and can run for weeks on a standard gas bottle.


  1. Cooling efficiency: Takes longer to cool down and can be affected by ambient temperature.
  2. Maintenance: More components that can fail, especially if not kept level during operation.
  3. Safety concerns: When running on gas, there’s a flame involved which can pose a risk if not well-ventilated or if there’s a gas leak.

In summary, the best fridge for your caravan depends on your travel habits and where you’ll be spending most of your time. If you’re frequently off-grid and away from mains power, a 3-way fridge might be the best choice. On the other hand, if you value rapid cooling and will have frequent access to mains power or are okay with recharging your batteries more often, a compressor fridge might be more up your alley.

Compressor vs. 3-Way Fridge

How much electricity does a 2-way fridge use on battery? How big of a battery do you need?

The electricity consumption of a 2-way (compressor) fridge in a caravan largely depends on the size of the fridge, the ambient temperature, the set temperature inside the fridge, and how often the fridge door is opened. However, I can provide a general estimate for understanding purposes.

Electricity Consumption:

  • A typical caravan compressor fridge might consume around 1 to 3 amps per hour on 12V, but this can vary based on the factors mentioned above.

Let’s use a rough estimate of 2 amps per hour for calculations:

  • Over 24 hours, the fridge would consume 2 amps/hour x 24 hours = 48 amp-hours (Ah).

Battery Size:

  1. For a single day without recharging, you’d need at least a 50Ah battery just to run the fridge.
  2. However, this doesn’t account for other appliances or lights you might be using. Additionally, it’s generally not recommended to deplete a battery entirely, as this can reduce its lifespan. Ideally, you’d only want to use up to 50% of a battery’s capacity to maximize its life.
  3. Given the 50% rule, if you only wanted to power the fridge, you’d need a 100Ah battery for one day of use. For multiple days without charging, multiply accordingly.
  4. Remember, other appliances, lights, or devices would increase the required battery size.

Other Considerations:

  1. Battery type: Lead-acid batteries are common, but lithium-ion batteries are more efficient, have a longer lifespan, and can often be discharged more than the 50% rule that applies to lead-acid. They’re also lighter but are generally more expensive.
  2. Solar panels: Many caravan owners use solar panels to recharge their batteries during the day, which can significantly extend the duration for which they can be off-grid.
  3. Driving: If you’re driving during the day, your caravan or RV’s alternator will typically charge the battery as well, which can offset some of the fridge’s power consumption.

In summary, while a 100Ah battery might be sufficient for a day or two for just the fridge, you’ll likely want a larger battery or battery bank if you’re planning to be off-grid for extended periods, especially if using other appliances. Solar panels and regular driving can also help replenish battery power.

Which fridge stays cooler during hot weather say around 38c

In hot weather conditions, around 38°C (100°F), the efficiency of how a fridge manages its internal temperature becomes crucial. Between the two types of caravan fridges we discussed (compressor and 3-way fridges), the compressor fridge typically has the advantage in such conditions:

Compressor Fridge (2-way fridge):

  • Performance in Hot Weather: Compressor fridges are less affected by external ambient temperatures. They operate using a motor-driven compressor and refrigerant, similar to household fridges. This means they can maintain colder internal temperatures more effectively even in hot environments.
  • Cool Down Time: They can cool down contents quickly and are more consistent in maintaining the desired internal temperature.

3-Way Fridge (Absorption fridge):

  • Performance in Hot Weather: 3-way fridges, especially when operating on gas, can struggle in very hot conditions. Their efficiency can drop as the ambient temperature rises, making it harder to maintain cooler internal temperatures.
  • Cool Down Time: They take longer to cool down, which can be a disadvantage when it’s very hot.

Other Factors to Consider:

  1. Insulation: Regardless of the fridge type, good insulation is vital. Ensure that the fridge has adequate insulation and that the seals are in good condition. This can make a big difference in performance during hot weather.
  2. Ventilation: Ensure that the fridge (especially 3-way fridges) has good ventilation. When a fridge is working hard in hot weather, it produces more heat, which needs to be effectively vented away to maintain efficiency.
  3. Positioning: If possible, try to position the fridge in a location where it won’t be directly exposed to sunlight, further helping with cooling efficiency.

In conclusion, when it comes to performing efficiently in very hot weather conditions, compressor fridges generally have an edge over 3-way fridges. However, proper installation, ventilation, and maintenance are also critical factors in ensuring optimal performance.

Compressor vs. 3-Way Fridge

Assuming I have a 190l fridge that draws on average 3amps and I have a 200amp lithium battery that is being recharged by a 200w solar panel how long can I use the fridge?

Let’s break down the situation:

  1. Fridge Consumption:
    • Your fridge consumes 3 amps per hour.
    • Over 24 hours, it will consume 3 amps/hour × 24 hours = 72 amp-hours (Ah).
  2. Battery Capacity:
    • You have a 200Ah lithium battery. One of the advantages of lithium batteries over lead-acid batteries is that they can be discharged more deeply without significantly affecting their lifespan. However, for the sake of battery health, it’s still wise not to drain them completely. Let’s assume you’re comfortable using 80% of its capacity: 0.8 × 200Ah = 160Ah available for use.
  3. Solar Recharge:
    • A 200W solar panel under ideal conditions (full sunlight, optimal angle, no shading, etc.) might produce around 200W/12V = 16.67 amps. However, real-world conditions are rarely ideal. Factors like the angle of sunlight, potential cloud cover, efficiency of the solar charge controller, and more can reduce this. A more realistic daily output might be 70-80% of the panel’s rated capacity.
    • Let’s assume 75% efficiency: 16.67 amps × 0.75 = 12.5 amps in actual charging.
    • Over a typical 5-hour solar generation day (this varies based on location and time of year), you might generate 12.5 amps × 5 hours = 62.5Ah.

Considering the fridge consumption and solar recharge:

  • Each day, after your solar recharge, your net consumption might be 72Ah (fridge) – 62.5Ah (solar) = 9.5Ah.
  • With 160Ah available in your battery (using the 80% rule), you could theoretically sustain this consumption for 160Ah / 9.5Ah/day ≈ 16.8 days.

However, this is a simplified and optimistic calculation. Other factors, such as other appliances drawing power, inefficiencies in the battery charging process, days with less sunlight, and the gradual decline of the battery’s maximum capacity over time, could reduce this time frame. But, with just the fridge running and daily solar input, you have a buffer of approximately 16 days with this setup.

What are reputable 2-way fridge brands in Australia

In Australia, several reputable brands manufacture and supply 2-way (compressor) fridges suitable for caravans, RVs, and other off-grid applications. Some of the well-regarded brands include:

  1. Waeco (Dometic): One of the most popular brands in Australia for portable and caravan fridges. They offer a range of sizes and models to suit various needs.
  2. Engel: Known for their durability and efficiency, Engel fridges have a long-standing reputation in the Australian market, especially for their portable fridges/freezers.
  3. Bushman: An Australian-owned company that has been around for over 35 years, they offer a range of durable and efficient fridges.
  4. EvaKool: An Australian-owned and operated company, EvaKool offers a wide range of fridges and freezers designed for the country’s challenging conditions.
  5. ARB: While they are primarily known for their 4×4 accessories, ARB also produces a line of portable fridges/freezers that are highly regarded for their performance and durability.
  6. Thetford: They offer a range of fridges that are specifically designed for RVs and caravans.
  7. Vitrifrigo: An Italian brand, but they have a presence in the Australian market. They are known for their sleek design and reliable performance.
  8. Nova Kool: While not as widely known as some of the other brands, they have a reputation for producing reliable and efficient compressor fridges.
Compressor vs. 3-Way Fridge

When selecting a fridge, it’s essential to consider the size, efficiency, features, and warranty provided by the brand. It’s also a good idea to read user reviews and perhaps seek recommendations from fellow caravaners or RVers to understand real-world performance and reliability.