There are different types of reefer container units, and choosing the ideal one is your first step towards success. Each type varies depending on its size, temperature requirement, and controlled and modified atmosphere.
This guide is made to give you the information you need to know about reefer containers. Knowledge of these things will help you choose the best unit for your needs.
Main Types of Reefer Container
A reefer container is also known as a refrigerated container. It is a specialized shipping unit used to maintain the ideal temperature during transportation. Different types are organized into three, such as integral, porthole, and genset reefer containers
Integral Reefer Container
An integral unit is a type of reefer container that has a built-in refrigeration system that controls a specific temperature and air circulation. This type of reefer container is commonly used to transport temperature-sensitive cargo where maintaining quality, freshness, and efficiency are important.
They can be powered using external sources, or they can use generator sets (gensets) and can handle varying temperatures from -35°C to +30°C. The integral reefer container also has digital displays and an alarm to monitor their status during transportation.
Porthole Reefer Container
A Porthole Reefer Container is also known as Conair unit. It is one of the earliest versions of refrigerated containers. This type of container was developed in the mid 1950s for the transportation of temperature-sensitive goods. They work through the external refrigeration units or a clip-on unit that you can attach to the container.
In this unit, you will see two openings where the cold air enters through the lower hole, travels on the T-bar flooring to circulate throughout your cargo, and exits through the upper hole. Keep in mind that a porthole reefer container can only maintain a fixed temperature, and you cannot adjust it. This means they are suitable for cargoes that don’t need a precise temperature to prevent them from spoiling during transport.
Non-Operating Refrigerated Containers (NORs)
Another option you can choose is the Non-Operating Refrigerated Containers (NORs). This is a type of reefer container where the refrigeration system is turned off and used as a standard dry box for a specific shipment. You should choose this type of reefer if your cargo requires thick insulation but does not need an active cooling unit.
Non-Operating Refrigerated Containers (NORs) are commonly used in cold chain logistics to manage imbalanced trade routes. This means that while a large amount of refrigerated cargo goes in one direction, only dry cargo is available for the return trip.
Because of the insulation they provide, you can use them for specific types of clean, dry goods, such as shoes, textiles, electronics, or dry groceries that benefit from the extra insulation. These reefer containers often come at discounted rates because cold chain providers need to move reefers back to high-demand locations. Using them for dry cargo allows the carrier to earn revenue during this move instead of paying to transport an empty box.
Types Based on Container Size
20’ Standard Reefer Containers
You can opt for 20’ Standard Reefer Containers if you are shipping a smaller volume of cargo. These units have an internal capacity of 28 m3 and external dimensions of 6.06m L x 2.44m W x 2.62m H. With a temperature range of -30°C to +30°C, these reefer containers work by maintaining the specific temperature of frozen and chilled goods.
They are mostly used for storing and transporting small-to-medium volumes of temperature-sensitive, perishable items that require a stable environment.
40′ Reefer Containers
While 20’ reefer containers are suitable for small-to-medium shipments, 40’ reefer containers are used for larger shipments. This unit has a 59.3 m³ capacity, an internal width of 2.28 m (7.5 ft), and an internal height of 2.25 m (7.4 ft). The door opening width is 2.28 m (7.5 ft).
These are mostly used for high-demand routes with larger cargo loads and can maintain a controlled temperature range from -30 °C to +30 °C.
If you are managing high-volume inventory, these containers will give you the necessary space needed while keeping your cargo at the required temperature.
40’ High Cube Reefer Containers
If you need more vertical space for your shipment, the 40′ High Cube Reefer Containers are the ideal choice. While standard reefer containers are usually 8ft 6in tall, high cube reefers stand at 9ft 6in tall externally. This additional foot of height gives you extra cubic capacity and better stacking options for larger or tall palletized cargo.
In terms of capacity, these units have a tare weight of 4,480 kg (9,880 lbs) and a payload capacity of 29,520 kg (65,080 lbs). The internal dimensions measure 11.58 m (38 ft) in length, 2.31 m (7.6 ft) in width, and 2.56 m (8.4 ft) in height, which gives you a total cubic capacity of 67 m³ (2,366 cu ft). To accommodate your larger loads, the door width is 2.31 m (7.6 ft) with a height of 2.56 m (8.4 ft).
In addition, these containers can maintain a controlled environment ranging from -35°C to +30°C. This is perfect for your temperature-sensitive goods that require extra overhead room for better airflow during transport.
Specialized Reefer Container Types
Controlled Atmosphere
If you are shipping fresh produce, controlled atmosphere (CA) reefer containers (often called smart reefer) slow down the ripening process. These units manage the internal atmosphere by reducing oxygen levels and increasing carbon dioxide while maintaining precise temperature and humidity.
By managing these gases, you slow down the respiration of fruits, vegetables, and flowers and extend their shelf life two to four times longer than standard refrigeration. Using a CA reefer maintains the freshness, color, and condition of your product.
Modified Atmosphere
If you are managing shorter trips or shipping goods that require less strict control, modified atmosphere (MA) reefer containers are the best choice. These units slow the ripening of your perishables by lowering the oxygen and increasing the carbon dioxide or nitrogen levels.
Unlike other systems, the initial setup involves injecting a specific gas mixture once at the start of the trip before sealing the container. Because the technology relies on a purge port or passive system, gas levels fluctuate as your produce breathes during transit. You will find these containers most effective for short to medium transport, which offer a balance of protection for your cargo.
Blast Freezer Reefer Containers
Blast freezers are a powerful way to quickly freeze fresh or frozen food. Using a strong fan and heavy-duty cooling, they blast cold air to drop the temperature of your goods from 50°C to -18°C in just a few hours. Their fast freezing method is important because it stops large ice crystals from forming. This helps you keep the original texture, taste, and vitamins in foods like meat, fish, and vegetables.
Fast cooling also slows down bacterial germs, which gives you a safer way to store your items for a long time. Whether you are moving seafoods, meats, or pre-made meals, these reefer containers keep your products in top shape.
Dual Temperature Reefer Container
Dual temperature reefer containers are flexible units that allow you to freeze and chill goods at the same time. They are available in 20-foot and 40-foot models and feature a movable wall and side doors so you can access two separate sections, each set to a different temperature.
These units use two full-capacity cooling systems to keep your products at the exact temperature setting they need, ranging from -30 °C to +30 °C. Because you can split the space, they are a cost-effective choice for mixed cargo or multi-temperature shipments.
You will find these containers useful for storing and moving high-value items like pharmaceuticals, chemicals, or food products that require both frozen and chilled sections in one trip. Some models even come with a built-in generator and spare parts to keep your cargo protected during long voyages.
Open-Side Reefer Containers
Open side reefer container features doors that swing open along the entire side, which provides you with a wide and unobstructed way to load large or bulky items. This side access design is perfect for your forklift to drive directly up to the cargo, which speeds up the work and helps prevent bumps or damage to the goods.
Beyond accessibility, these units are built to maintain a steady cargo temperature to keep your items fresh and in good condition throughout the entire shipment. For best results, we recommend precooling products before loading to prevent heat from being trapped inside the container during this process.
This type of reefer container is also available in 20ft and 40ft long and is perfect for oversize or bulky cargo that requires easy loading.
Ultra-Low Temperature (ULT) Reefer Containers
Ultra-Low Temperature (ULT) Reefer Containers are designed to keep your cargo at extreme freezing levels from -40 °C down to -70 °C. These units use High-Density Polyurethane Foam (PUR) or Vacuum Insulated Panels (VIP and a specialized vacuum valve to manage intense temperature differences between the inside and the outside air.
The heavy-duty refrigeration unit on these reefer containers maintains the required temperature for your sensitive goods like vaccines, medical samples, and seafood. High-value products requiring constant extreme cold are kept safe by built-in alarms and a backup power system to provide you with a highly reliable solution for transport.
How to Choose the Right Reefer Container?
Choosing the right unit keeps your goods protected and helps your operation run efficiently. Consider the following factors to find the best fit for your needs.
Based on Cargo Types
Every cargo category has its own unique requirements for preservation. You must consider that the specifications for your inventory go beyond just size; they also include precise settings for temperature, humidity levels, and proper air circulation. While 20’ standard reefer container unit is suitable for smaller batches of perishables or delicate biological samples that often require specialized materials and structural designs to prevent contamination or damage. Matching these factors to your specific product keeps the load stable throughout the journey.
Required Temperature
You must match the units’ cooling capacity and atmospheric control to your specific needs. While some products require a deep freezer reaching extreme levels like -70 °C, others only need to stay chilled at moderate temperatures.
Beyond just cooling, certain sensitive items benefit from Modified Atmosphere (MA) or Controlled Atmosphere (CA) settings, which adjust oxygen and carbon dioxide levels to slow down the ripening process and extend shelf life. Choosing a unit that supports these precise environmental adjustments keeps your high-value cargo in good condition.
Transport Method
Consider how your goods will be transported. If your logistics involve long-haul trucking or remote rail paths where a power source is unavailable, you should look for units compatible with gensets (portable generators) to maintain continuous cooling.
Selecting a container that fits the specific power and structural demands of sea, rail, or road transport helps you avoid interruptions in the supply chain.
Budget and Operational Needs
You should weigh the initial rental or purchase cost against long-term efficiency. For example, larger 40’ High cube reefer containers offer more vertical space and a higher volume, which can be more cost-effective for your high-capacity shipping needs.
Evaluating the energy consumption of the refrigeration unit and the durability of the insulation also helps you minimize overhead costs over time.
Access Requirements
Accessibility can dictate your turnaround time. For standard loading, a rear door unit works well. However, if your operations require forklift access or the movement of oversized items, an open side reefer gives you with necessary clearance to speed up your workday. Selecting a unit that matches your loading dock setup and labor flow helps you maintain efficiency during high-volume periods.
Making the Right Choice
Choosing the right reefer container is a strategic decision that impacts the safety of your inventory and the efficiency of your logistics. By carefully evaluating your cargo’s specific requirements, you can select a unit that protects your high-value products and optimizes your operational costs.
Investing in time to match technical specifications with your business goals helps you maintain a seamless cold chain and achieve long-term success.
If you need more guidance on these topics or require a custom cooling solution, contact our team. We are here to help you navigate the technical details and find the perfect equipment for your specific needs.
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