Boxxport Blog

Reefer Containers are the short form for refrigerated containers that are most commonly known as reefers. They are specifically designed to store or transport special types of cargo to cater to the certain needs of the shippers. We will look in detail at what makes reefers different from other shipping containers.

Shipping containers have been there with us since the 1950’s helping us in our daily lives by getting the products safely to us. They have been helping mankind from the backdrop by giving storage, shipping, and home/office/other solutions. There are various container types that are available in different sizes like an open-top, insulated, dry van, and many others that the shippers use for different purposes.

The list of different types of shipping containers is given below that fulfill various container purposes.

Dry Van	Open Top	Hard Roof Open Top
Pallet Wide	Flat Rack	Platform
Double Door	Insulated	Reefer
Side Door	Bulkers	Tanks

Reefers are the containers that provide protection to perishable goods like fresh fruits, seafood, vegetables, flowers, dairy, pharmaceuticals, photographic film, and other such goods that can easily be spoiled if stored or shipped in otherstandard ISO containers.Now you will be wondering how!

There is no need for brainstorming as the answer is a simple one. The reefers are temperature-controlled containers that maintain the temperature between -25 degrees to 30 degrees Celsius. They are fitted with T-shaped decking to help them in distributing chilled air from the floor. This is why they are also known as bottom air delivery units. The air delivery design ensures that the temperature is maintained throughout the container by a steady and powerful airflow. Disregarding the temperature outside, it can maintain the colder and warmer temperature both inside the shipping container.

They use an external power supply to maintain the temperature inside and for its overall operations. A generator is attached to the refrigerated containers to aid them with cooling or electricity. The reefers can be transferred by trucks or in ships so the generator is fitted with both fuel and electric power panels. This helps the reefer units in getting safely delivered without altering the temperature in any type of situation. They also ensure the air flows consistently throughout the shipment to maintain the perfect air exchange in the container.

Types of Reefers

There are different types of reefer containers to cater to the needs of shippers based on proficiency, uses, goods type, and other such requirements.

Closed Reefer: It is a single-piece conventional reefer that is fitted with all-electric automatic cooling and heating units and has an inherent front wall.

Modified Atmosphere/ Controlled Atmosphere Reefers: The containers are fitted with an air exchange system to keep the atmosphere constant continuously by replacing the consumed oxygen. This quality makes the reefers maintain equilibrium between the airflow and deterioration rate.

Automatic Fresh Air Management Reefer: The air can be automatically adjusted in such types of containers to maintain the temperature. It controls the composition of carbon dioxide, oxygen, and other such gases and extends the serviceable life of the merchandise.

Different dimensions of Refrigerated Containers

They are available in different sizes of 20ft,40ft high cube, etc. to provide the shipping solutions to the special cargo. The approximate data of dimensions are given below. 

 20ft Reefer Containers

Internal dimension	17’10 x 7’6 x 7’5
External dimension	19’10 x 8’ x 8’6”
Door Opening	7’6 x 7’4
Max gross weight	67200 pounds

40ft High Cube Reefer Containers

Internal dimension	38’2” x 7’6 x 8’2
External dimension	40’ x 8’ x 9’6”
Door Opening	7’6 x 8’3
Max gross weight	67200 pounds

What are the benefits of Reefer Containers?

The refrigerated containers provide huge benefits to help the merchandise in getting shipped safely. 

• They are self-contained refrigerated units so the shipper can easily store the goods in them, despite looking for cold storage instantly. 
• Because of being available in different dimensions and fitted with gen-sets, they are perfect for every type of transportation whether it’s by sea, road, or air. 
• They can be compartmentalized into different departments by varying temperatures. So the shipper can easily load frozen and chilled merchandise in the same reefer. 
• Being made of heavy-duty steel they can withstand any environmental situations and still keep the goods safe. 
• The reefers increase the shelf life of goods by the continuous circulation of cool air. 

Basic Sections of Refrigerated Containers

Compressor Section

• The reefers consist of compressors and a power cable storage compartment. The power transformers can be fuel operated or electrically operated depending on the mode of transport.
• It consists of modulating and the suction solenoid valve that controls the gas flow in the refrigerated containers.  
• It is fitted with a moisture liquid indicator, pressure-relieve valve, filter drier, and other such safety fittings to see the container doesn’t see any malfunction.
• The section also contains an electric monitoring system along with sensors to see the proper functioning of shipping containers. 

Condenser Section

• This section consists of condenser fans, a motor to rotate the fan, a condenser coil, and a condenser saturation sensor to see that the condensation unit works properly. 
• A water-cooled condenser is used in some reefer units rather than air-cooled to increase the efficacy of the reefers. 
• The air-cooled condensers pull the air from the bottom and discharge it through the center of the unit.

Evaporator Section

• Temperature sensing bulb, return recorder bulb sensor and thermostat expansion valve are fitted in this unit to maintain the temperature and flow of refrigerant inside the evaporator of the shipping unit. 
• It has an evaporator coil, heater, and drain pan, defrost, and heat transmission switches to help the functioning of the evaporation unit. 
• The air is circulated throughout the shipping container by an evaporator fan by pulling air to the top of the reefer and then the air is directed towards the evaporator coil to heat or cool it. The air is then discharged in the container through the bottom of the unit 

Fresh Air Makeup Vent

• The fresh air vent is used to keep the foods fresh by ventilating the refrigerated container. The vent must be closed when keeping frozen goods. 
• The air exchange of the vent depends on the static pressure differential. 

Components of Reefer Containers

Generator: A generator is the basic and most needed component of any reefer as it is the power source of the reefer container. The generator can be electrically or fuel-powered to ensure that the temperature in the unit is maintained continually without any interruption. It can be clipped on the side or mounted on the chassis of the shipping container. 

Humidity Control: Humidity control is the most needed component in a reefer as when dry air causes the goods to dry up, the moisture in the air will lead to the growth of bacteria and mold. The humidity control feature helps in the dry packing of the goods and also sees that food items won’t get rotten.

Temperature Control: The temperature is maintained in the unit by using water or air cooling systems. The unit is fitted with a compressor that sucks in all the refrigerant gases and then liquefies them by compressing them. The air is then drained outside by the evaporator. 

GPS Chip: The GPS chip is installed in the reefer containers to oversee the security of packages. As the shipping container goes through various modes of transportation and ports during shipping, the security of packages becomes cardinal. The chip also shows the temperature status of the container to see the goods remain in the safe temperature lines. 

Practices to follow in Refrigerated Unit Shipping

Proper steps are needed for the safety of cargo in reefers. 

• The cargo should be packed tightly to make sure that it stays stable. 
• Follow the standard temperature and humidity settings. 
• The cargo should be pre-cooled when needed to see that it shouldn’t get spoiled before loading. 
• The ventilation and its settings need to be properly checked as in the absence of proper ventilation, the merchandise can become stale.  
• The airflow should be maintained properly and it should not get restricted from anywhere to maintain proper circulation in the refrigerated container. 
• The goods should not be loaded above the red mark.
• The cargo should be filled away from the T-floor space. 
• The overloading of cargo should not be carried on in the shipping containers as the airflow will be restricted. 

Safety and Operating Precautions

The safety of the shipping unit is mandatory for overall functioning. So the loading operations should be carried on following certain measures. 

• The safety gloves and glasses should be worn while loading and also during the charging of refrigerants.
• While working with evaporator and condenser fans, one should keep hands, tools, and clothing away. 
• The power supply, all circuit breaker, and start-stop button needs to be switched off when loading the cargo. 
• Keep clear from any electrical safety devices. 
• The electrical fire should be put off with a CO2 extinguisher rather than other extinguishers.
• During the charging of refrigerant, the compressed gases need to be handled with care. 
• Officers and crew should know about the phosphine gas hazard or asphyxiation hazard in non-ventilated spaces and be prepared for it always. 

Key Point to Keep in Mind

The most basic thing that one should know is that the reefer maintains the temperature of pre-cooled merchandise. It doesn’t lower the temperature on its own. 

Refrigerated Containers/reefers are special shipping containers that help the shippers in storing and shipping perishable, pharmaceuticals, and other such goods. They are perfect for storing such cargo that needs a specific temperature. 

BOXXPORT is one-of-a-kind online container trading platform and our container services are unmatchable and unsurpassable. We provide refrigerated containers at the most efficient prices and other than reefers we have different varieties of containers like dry van, open-top, hardtop open top, flat rack, insulated containers, and many others. Our special SOC containers are effective in saving you from heavy detention charges. We provide new or used containers to provide you with all the shipping and storage solutions.