Understanding reefer containers and refrigerated shipments

General cargo containers are very useful when used in transportation of consumer goods that do not require special conditions.

You can use a 20ft dry container when transporting textiles from China to USA, 40ft dry container when transporting automobile spare parts from Japan to Holland or 45ft pallet wide dry container when transporting mobile phones from Tawian to UK.

But some goods require special conditions. 

For example you can not carry fresh fruits with a general cargo containers from Brazil to European Union countries.

The average transport time between a port of loading in Brazil to Port of discharge in Europe is 25-35 days.

If you ship fresh fruits with a general cargo containers from Brazil to Europe, the cargo turns into trash and lost its economical value during the transportation.


As a result you have to ship perishable goods via reefer or refrigerated containers.

Today I am going to explain the basics of reefer containers and refrigerated shipments. 

After reading this article you should be able to answer below questions:
  • What is a reefer container?
  • What kind of goods should be shipped with refrigerated containers?
  • What are the key benefits of reefer shipping?
  • How many different types of protection capabilities exists in modern reefer containers?
  • What are the differences between atmosphere, humidity and temperature control systems? 
  • What are the types of temperature controls available in reefer container in global market?
  • What are the types of reefer containers?
  • Are internal dimensions of a reefer container and general purpose cargo container the same or are there any differences exist?
  • How many pallets fit in a reefer container?
  • What are the names of well-known reefer container carriers in a global scale?
What is a reefer container?

Reefer containers or refrigerated containers are designed for transport of perishable goods in a temperature, humidity and atmosphere controlled environment.

What kind of goods should be shipped with reefer containers?
  • Fresh vegetables and fruits: Lychees, grapes, grapefruits, mango, avocados, bananas, kiwi, apples, stone fruits etc.
  • Frozen Vegetables and fruits: IQF frozen vegetables and fruits such as IQF ocras, IQF artichokes, IQF spinach, IQF green peas, IQF Strawberry, IQF Figs, IQF Apricots etc.
  • Fresh fish: Fresh seabass, fresh sea bream, fresh sea trout, fresh pangasius, frozen sea food etc.
  • Frozen Fish: IQF seabass, IQF sea bream, IQF sea trout, IQF pangasius, IQF frozen sea food etc.
  • Other Foodstuff: Chilled and frozen meat, milk and dairy products, margarine, egg, juice and concentrate, chocolate, butter etc.
What are the key characteristics of a reefer container?
  • They are designed to keep the temperature, humidity and atmosphere at a constant value during the transportation.
  • Some of them can supply fresh air to the inner area during the carriage.
  • All of their walls are supported with polyurethane foam which is also known as a “sandwich-panel” to provide maximum insulation. 
  • They are equipped with a compact-design compressor unit with air-cooled condenser, which can supply both cooling and heating interchangeably. 
  • Temperature can be set to + 35°C to –35°C.
Atmosphere, humidity and temperature control of a reefer container?
  • Atmosphere Control: Some refrigerated containers are equipped with special tools to keep the correct levels of Oxygen (O2), Carbon Dioxide (CO2) and Nitrogen (N2) inside the reefer unit. Re-modifying the composition of the air in the container (especially CO2 and O2 levels) significantly slows the ripening process of fresh produce and lengthens shelf life.
On below video Maersk Line explains the fundamentals of atmosphere control in a refrigerated carriage.


  • Humidity Control: Some goods need a constant level of humidity inside of the refrigerated container. constant level of humidity will be achieved via a process called dehumidification. Most of the refrigerated containers can keep the relative humidity level within the range of 95 to 55% inside the container during the carriage period.
  • Temperature Control: Atmosphere and humidity controls are extra performances and not all refrigerated containers could supply such options, but temperature control is the core element of a refrigerated container and you should expect this performance from all reefer containers without any exception.
Source : http://www.cma-cgm.com/static/Communication/Attachments/CMACGM_Reefer_Brochure_2014.pdf
There are three types of temperature controls available in the market:
  • High freezer containers: They are ideal for products which require extremely low temperatures down to -35°C such as ice cream, frozen fish and frozen meat.
  • Cold treatment: A highly precise process where goods (mainly fruits) are kept at a low temperature for a predetermined, uninterrupted period to kill the pests.
  • Multi-temperature system: Used for some commodities, such as tomatoes or potatoes, that may require temperature changes during the voyage.
Types of reefer containers
  • 20’ Standard Reefer Container: This container has the 5,535mm internal length, 2,284mm internal width and 2,224mm internal height. Its volume is 28.7 cbm. (Hapag Llyod)
How many euro pallets can be fitted in a 20 ft reefer container?You can fit 10 euro pallets (80cmx120cm) in a 20ft reefer container.How many standard pallets can be fitted in a 20 ft reefer container?You can fit 9 standard pallets (100cmx120cm) in a 20ft reefer container.
  • 40’ Standard Reefer Container: This container has the 11,563mm internal length, 2,294mm internal width and 2,161mm internal height. Its volume is 60 cbm.(Hapag Llyod)
How many euro pallets can be fitted in a 40 ft reefer container?You can fit 23 euro pallets (80cmx120cm) in a 40ft reefer container.How many standard pallets can be fitted in a 40 ft reefer container?You can fit 20 standard pallets (100cmx120cm) in a 40ft reefer container.
  • 40’high cube reefer container: This container has the 11,580mm internal length, 2,290mm internal width and 2,402mm internal height. Its volume is 67,36 cbm.(Hapag Llyod)
How many euro pallets can be fitted in a 40 ft high cube reefer container?You can fit 23 euro pallets (80cmx120cm) in a 40ft high cube reefer container.How many standard pallets can be fitted in a 40 ft high cube reefer container?You can fit 20 standard pallets (100cmx120cm) in a 40ft high cube reefer container.
  • 45’ pallet wide high cube reefer containers: This container has the 13,280mm internal length, 2,440mm internal width and 2,582mm internal height. Its volume is 83,7 cbm.(Cronos)
How many euro pallets can be fitted in a 45 ft pallet wide high cube reefer container?You can fit 32 euro pallets (80cmx120cm) in a 45ft pallet wide high cube reefer container.How many standard pallets can be fitted in a 45 ft high cube reefer container?You can fit 26 standard pallets (100cmx120cm) in a 45ft pallet wide high cube reefer container.
Important points of consideration when making refrigerated shipments
  • Refrigerated shipments are expensive than dry cargo shipments as reefer containers require special equipment and they consume electricity from beginning to the end of the carriage.
  • Refrigerated containers are rare in numbers comparing to general purpose dry cargo containers.
  • You have to be very careful especially on pick periods when everybody is rushing to ship their orders, because you may not be able to find a refrigerated container to load your cargo on time one of those tight times.
  • Refrigerated containers have narrower internal dimensions comparing to dry containers. Be careful with the pallet loading numbers before giving any offer to your customer.
  • Not all reefer containers have the same specifications. Please try to understand your cargo requirements and type of refrigerated container that you may be in need of. Then contact local refrigerated transportation specialist of the carrier to get detailed information.
  • Do not stick with only one carrier. Try to reach all refrigerated container carriers that have services for your carriage.
  • Do not choose the cheapest option. You may loose thousands of dollars while trying to save couple of hundred dollars from the freight cost.
  • Try to understand pros and cons of each carrier. Check container specifications, learn transit time and ask all questions in your mind to the reefer container customer service specialist.
Top reefer container carriers around the world
  • CMA CGM- With a centralized organization dedicated to Reefer activity combined with a network of experts located in over 85 countries, CMA CGM is the global Reefer partner with local expertise in refrigerated transport.
          Website: http://www.cma-cgm.com
  • ZIM- ZIM’s global reach and local branch services enable timely delivery of refrigerated shipments anywhere in the world.                         
          Website: www.zim.com
  • Hamburg Süd- With long experience in the transport of perishable cargo, Hamburg Süd ranks among the top five reefer container carriers worldwide and stands for the highest schedule reliability and shortest transit times. 
          Website: http://www.hamburgsud-line.com
  • Maersk- Maersk Line brings unrivalled expertise to the world of reefer transport. We began doing refrigerated transport back in 1936, and today we are the biggest player in the industry. This means, over the years, we have invested in equipment and innovation. Today we have the largest fleet, including the newest state of the art reefer containers, as well as the most comprehensive global network. 
          Website: http://maersklinereefer.com/
  • Hapag-Lloyd- Hapag-Lloyd is one of the largest reefer carriers and serves the trade with transport solutions for a large variety of high quality reefer products. Hapag-Lloyd has a profound expertise in the transportation of temperature-sensitive products, this includes perishable cargoes, high value reefer cargoes such as pharmaceuticals, healthcare products and more. 
          Website: www.hapag-lloyd.com
  • Evergreen- Evergreen offers temperature-controlled transportation throughout its global network covering Asia, Europe, the Mediterranean, the Americas, Africa, and Australia. All types of commodity are carried including fruit, vegetables, meat, seafood, dairy products, confectionery and temperature sensitive non-alimentary and pharmaceutical products. 
          Website: http://www.evergreen-marine.com/tbi1/jsp/TBI1_RefConService.jsp
  • COSCO- As a premier carrier of refrigerated commodities for both import & export, COSCO has been very successful in providing the most specialized handling and reporting to meet the most stringent demands of the top importers and exporters in the world. 
          Website: http://en.cosco.com/