Technical Information > How to Set Temperature in a Reefer Shipping Container?

How to Set Temperature in a Reefer Shipping Container?

Refrigerated shipping container, commonly called a reefer container, is a pillar of global logistics. These containers are designed for transporting temperature-sensitive goods, such as food, pharmaceutical products and electronics, ensuring their freshness and quality during transport. Reefer containers, equipped with advanced air conditioning systems, maintain specific temperature ranges, typically between -35 °C and +30 °C, depending on the requirements of the transported cargo. Understanding how to properly set and control temperature in a reefer container is key to maintaining the cold chain and the integrity of perishable goods. This article provides a comprehensive guide to understanding the components, functions and best practices when using reefer containers.

What is a Reefer Container?

Refrigerated container, or also reefer container, is a specialized cargo container equipped with an integrated cooling unit. Its main function is to maintain a controlled internal temperature suitable for transporting perishable goods or temperature-sensitive cargo. Modern reefer containers have become indispensable in cold chain logistics, as they ensure that goods are delivered in optimal condition.

Key Features of Reefer Containers

  1. Temperature Regulation: Reefer containers are not designed to cool cargo, but to maintain a pre-cooled state of goods. From frozen seafood to chilled fruit, temperature ranges can be set between -35 °C and +30 °C depending on the type of cargo.
  2. Humidity Regulation: Many reefers allow humidity settings in the range of 60% to 85% to accommodate sensitive goods such as fresh fruit and vegetables.
  3. Ventilation Systems: Advanced ventilation systems allow controlled air flow and gas exchange, preventing deterioration caused by gases such as ethylene, which is released by some types of fruit.
  4. Power Supply: Cooling units require a continuous power source. Depending on the logistics arrangement, power is supplied from the ship’s electrical grid, a portable generator (genset) or terminal electricity.
  5. Microprocessors and Remote Monitoring: Top-of-the-line reefers have microprocessors that allow operators to monitor and record parameters such as temperature, humidity and ventilation settings. Remote monitoring systems provide real-time information for better control.

Why is Temperature Regulation Important?

Maintaining precise and stable temperature inside a reefer container is essential for several reasons:

  • Preservation of Goods: Perishable goods such as meat, dairy products, fruit and pharmaceuticals depend heavily on strict temperature regulation to prevent deterioration.
  • Cold Chain Integrity: The cold chain, a series of temperature-controlled environments, ensures that goods are stored and transported under optimal conditions from the point of origin to the destination.
  • Regulatory Compliance: Many industries, particularly the pharmaceutical and food sectors, have strict regulations that require specific temperature ranges during transport.

Components of a Reefer Container

Understanding the components of a reefer container is essential for its efficient operation. Below is a detailed description of key parts:

1. Cooling Unit

The cooling unit is the heart of the reefer container. It maintains the required temperature by circulating cold air. Depending on the model, some units can maintain extreme temperatures ranging from -65 °C to +40 °C, allowing the transport of highly sensitive goods such as vaccines and frozen seafood.

2. Control Panel

The operator uses the control panel to set and monitor temperature, humidity and ventilation levels. Modern panels also display error codes, allowing for quick troubleshooting.

3. Air Flow System

The T-shaped floor design ensures consistent air circulation in the container. Cold air enters from below and rises upward, eliminating temperature inconsistencies.

4. Humidity Regulation

The humidity level can be adjusted to the cargo. For example, fresh fruit and vegetables may require higher humidity settings to retain moisture, while dry goods require lower levels.

5. Ventilation System

Ventilation settings allow the operator to control the supply of fresh air and the removal of gases. This is especially important for goods such as fruit, which releases ethylene gas that accelerates ripening.

6. Drainage System

Excess moisture caused by condensation is removed by the drainage system, preventing water accumulation and preserving cargo integrity.

How to Set Temperature in a Reefer Shipping Container

Proper temperature setting is essential to maintain cargo quality. Follow these steps to ensure accurate temperature regulation:

Step 1: Pre-cool or Pre-chill the Cargo

Always pre-cool goods to the required temperature before loading. Reefer containers are designed to maintain, not to reduce cargo temperature.

Step 2: Turn On the Unit

  • Connect the reefer container to a reliable power source.
  • Switch the cooling unit to the “ON” position and let the system complete the self-test.

Step 3: Set the Desired Temperature

  • On the control panel, use the “UP” and “DOWN” arrows to set the desired temperature.
  • Confirm the setting by pressing the “ENTER” button. Make sure the temperature matches the cargo requirements (e.g., -18 °C for frozen products or +5 °C for chilled goods).

Step 4: Set Humidity and Ventilation

  • Set the humidity level using the control panel, especially for humidity-sensitive goods.
  • Adjust ventilation settings to ensure proper gas exchange and air flow.

Step 5: Monitor and Maintain

  • Use remote monitoring systems to track internal conditions and detect any deviations.
  • Regularly check the control panel for alarms or error codes.

Best Practices for Operating Reefer Containers

To maximize the efficiency and lifespan of reefer containers, follow these best practices:

  1. Proper Loading Techniques: Distribute cargo evenly to ensure space for air circulation.
  2. Regular Maintenance: Clean the cooling unit, check seals and ensure the drainage system is not clogged.
  3. Use Monitoring Tools: Equip the container with temperature probes and data loggers for continuous monitoring.
  4. Minimize Door Opening: Limit door opening to prevent temperature fluctuations.
  5. Perform Pre-Trip Inspection (PTI): Before loading, check the container’s insulation, power supply and cooling system.

Applications of Reefer Containers

Reefer containers have wide applications in industries such as:

  • Food and Beverages: Transport of frozen meat, dairy products, seafood and fresh fruit.
  • Pharmaceuticals: Safe delivery of temperature-sensitive vaccines, medicines and medical devices.
  • Electronics: Protection of temperature-sensitive equipment during transport.

Reefer shipping containers are an integral part of modern logistics, ensuring safe and efficient transport of temperature-sensitive goods. By understanding their components, functions and best practices, operators can maintain the cold chain and guarantee product quality. Whether it is fresh fruit, life-saving vaccines or high-value electronics, mastering the operation of reefer containers is key to meeting industry standards and customer expectations.