Shipping fresh produce, frozen food or temperature-sensitive goods across thousands of kilometres requires more than a standard shipping container.
In international sea freight, a reefer container helps maintain controlled temperatures throughout the journey. But how does it work? What sizes are available? And how can businesses choose the right refrigerated container for their shipments?
What Is a Reefer Container and What Is It Used For?
A reefer container, also known as a refrigerated shipping container, is a temperature-controlled container equipped with an electric refrigeration system.
Unlike a standard dry container, a reefer is designed to transport goods that require specific temperature conditions.
Reefer containers are commonly used for:
- Food products: fruits, vegetables, meat, fish and frozen goods.
- Pharmaceutical products: certain medicines and healthcare products requiring temperature-controlled transport.
- Flowers and plants: products sensitive to temperature changes during international shipping.
Refrigerated containers used in international transport are covered by ISO 1496-2:2018, which establishes technical specifications and testing requirements for thermal freight containers.
How Does a Reefer Container Work?
A reefer container uses an electrically powered refrigeration system to maintain the required temperature throughout the shipping journey.
Its operation relies on three essential components:
- Refrigeration system: a compressor-based cooling unit that regulates the internal temperature.
- Air circulation: fans distribute conditioned air throughout the container to maintain consistent conditions.
- Temperature monitoring: sensors and control systems help monitor and record transport conditions.
During sea freight transportation, the container is connected to the vessel’s electrical supply. Suitable power connections must also be arranged during port operations and inland transport.
What Types of Cooling Systems Are Used in Refrigerated Transport?
Refrigerated transport equipment can use different cooling technologies and configurations:
- Integral refrigeration systems: the cooling unit is built into the container. This is the most common configuration for modern reefer containers used in international sea freight.
- Remote refrigeration systems: certain specialised or older configurations rely on external refrigeration equipment rather than an integrated unit.
- Specialised ultra-low-temperature systems: designed for goods requiring temperatures significantly below those supported by standard reefer equipment.
Most modern maritime reefer containers use vapour-compression refrigeration technology, combining a compressor, condenser, expansion device and evaporator to regulate temperature.
External generators may provide electricity during inland transport, but they are power sources rather than separate cooling technologies.
For additional technical information, consult the white paper on refrigerated maritime containers, developed through the Greener Reefers initiative with contributions from GIZ and the Kuehne Climate Center.
What Is the Typical Operating Temperature Range of a Reefer Container?
Standard reefer containers commonly support temperature settings of approximately -25°C to +25°C, although the exact operating range varies by manufacturer and model.
Specialised ultra-low-temperature containers can maintain significantly lower temperatures for products requiring exceptional preservation conditions.
The correct setting depends on the type of cargo, its preservation requirements and the specifications of the equipment selected.
Important: a reefer container is primarily designed to maintain cargo at its required transport temperature, not to rapidly cool products loaded at an unsuitable temperature. Proper pre-cooling is essential when required.
Reefer Container Dimensions and Capacities
Two of the most common refrigerated shipping container formats are the 20-foot reefer and the 40-foot High Cube reefer.
| Specification | 20ft Reefer | 40ft High Cube Reefer |
|---|---|---|
| Internal length | Approx. 5.46 m | Approx. 11.58 m |
| Internal width | Approx. 2.29 m | Approx. 2.29 m |
| Internal height | Approx. 2.27 m | Approx. 2.56 m |
| Nominal internal volume | Approx. 28 m³ | Approx. 67 m³ |
| Typical use | Smaller shipments or dense cargo | Larger-volume shipments |
Figures are indicative. Actual dimensions and loading capacity vary depending on the manufacturer and equipment model. Always confirm the specifications before booking.
Which Reefer Container Should You Choose?
The 20ft reefer container is suitable for shipments requiring less loading space, particularly when transporting relatively dense goods.
The 40ft High Cube reefer container offers greater internal volume and additional height, making it suitable for larger shipments.
However, container size is not the only consideration. Businesses should also evaluate cargo weight, packaging, temperature requirements, airflow and equipment availability along the planned shipping route.
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What Are the Benefits of Using a Reefer Container?
Refrigerated sea freight offers several advantages for companies importing or exporting perishable and temperature-sensitive goods.
1. Preserving product quality
Maintaining appropriate temperatures helps reduce the risk of deterioration during long sea journeys.
2. Shipping perishable goods over long distances
Reefer containers make it possible to transport temperature-sensitive products between continents, including on routes lasting several weeks.
3. Adapting storage conditions to the cargo
Depending on the equipment, ventilation, humidity and controlled-atmosphere settings may be available for specific types of goods.
4. Improving cold chain visibility
Monitoring equipment can help track and record temperature conditions throughout the shipment.
Practical Example: Exporting Fresh Produce by Sea
Imagine a French food exporter shipping fresh fruit to an overseas market.
Before loading, the company must establish the correct transport temperature, prepare the products and select a suitable refrigerated container.
Pallet positioning is also important to ensure that air can circulate effectively around the cargo.
The International Maritime Organization (IMO) provides guidance on safe container packing and cargo securing through the CTU Code, developed jointly with the ILO and UNECE.
What Are the Disadvantages of Reefer Containers?
Despite their benefits, refrigerated shipping containers also involve operational constraints.
- Higher transport costs: refrigeration equipment, electricity consumption and additional handling or monitoring services can make reefers more expensive than standard containers.
- Continuous power requirements: the refrigeration unit needs a reliable electricity supply throughout the relevant transport stages.
- Reduced internal loading space: insulation and refrigeration equipment occupy some of the available space.
- More demanding cargo preparation: products must be packed and loaded correctly, with sufficient space for airflow.
- Risk of technical failures: refrigeration problems or prolonged power interruptions can expose sensitive goods to temperature fluctuations.
These limitations do not make reefer containers unsuitable for international shipping. They highlight the importance of proper shipment planning and coordination.
How to Organise Sea Freight with a Reefer Container
Successful refrigerated sea freight requires careful coordination before, during and after the ocean journey.
Here are five essential steps:
- Identify the cargo requirements: temperature, shelf life, ventilation and specific regulations.
- Choose the appropriate container: dimensions, loading capacity and refrigeration performance.
- Prepare the shipment: packaging, palletisation and pre-cooling when necessary.
- Coordinate transport operations: power supply, port handling, customs formalities and final delivery.
- Monitor shipping conditions: temperature records, shipment visibility and incident management.
For some perishable food shipments, specific rules may also apply during inland transport.
The United Nations Economic Commission for Europe (UNECE) publishes the ATP Agreement, which establishes requirements for transporting certain perishable foodstuffs and the equipment used.
Its scope primarily covers international road and rail transport, as well as certain short sea crossings of less than 150 km under specified conditions. It does not generally regulate long-distance ocean freight operations.
For shipments involving inland delivery, Nexline also provides road freight solutions.
Businesses should also anticipate documentation and customs requirements. Discover Nexline’s customs declaration services for international shipments.
FAQ: Frequently Asked Questions About Reefer Containers
What Are the Best Reefer Containers for Refrigerated Transport in Europe?
There is no single best reefer container for every shipment.
The 20ft reefer and 40ft High Cube reefer are common options, but the most suitable choice depends on cargo volume, required temperature, product characteristics and transport conditions.
Specialised equipment may also be necessary for ultra-low-temperature shipments.
Which Companies Specialise in Refrigerated Container Leasing in Europe?
Several types of companies provide refrigerated container solutions across Europe, including specialised container leasing companies, equipment suppliers and logistics providers.
The right partner depends on whether a business needs to lease a refrigerated container, purchase equipment or arrange an international temperature-controlled shipment.
For businesses requiring refrigerated sea freight rather than standalone container rental, Nexline Group helps coordinate international shipping operations, from equipment selection to transport planning.
Explore our sea freight solutions to learn more about our international transport services.
What Is the Difference Between a Reefer Container and a Standard Shipping Container?
A standard dry container transports goods that do not require active temperature regulation.
A reefer container is equipped with an electric refrigeration system that maintains the conditions required for temperature-sensitive cargo.
How Much Does Reefer Container Shipping Cost?
The cost of refrigerated sea freight depends on several factors, including container size, shipping route, equipment availability, transport duration, power requirements and associated logistics services.
For shipments involving complex port operations, additional container-related charges may also arise.
Learn more in our guide to demurrage vs detention and how to avoid container charges.
A tailored quotation is the most reliable way to estimate the total shipping cost.
Nexline: Your Partner for Reefer Container Shipping
Transporting temperature-sensitive goods requires more than choosing a refrigerated container. Each stage of the journey must be coordinated to help preserve cargo quality and ensure reliable delivery.
With its international sea freight solutions, Nexline Group helps businesses organise temperature-controlled shipments, taking into account cargo characteristics, shipping routes and operational requirements.
Whether you are exporting fresh produce, transporting frozen goods or managing sensitive international shipments, our teams can help identify the most suitable logistics solution.
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