Refrigerated containers are actually shipping containers that are able to control temperature and thus allow all sorts of differentproducts (food, chemicals, paint etc) to travel across the world. The”refrigerated container” name can be abit misleading as actually the temperature can be controlledwithin a range of -25C to +25C depending on the product requirements. Sometimes they are referred to as reefer containers or ambient temperature containers. Whatever you call them they come in sizes 10ft, 20ft and 40ft.

New 20ft Refrigerated Container
The most common type of refrigerated containerare those which have an integral refrigeration unit which controls the temperature within the refrigerated shipping container. When on ship they are connected to the ships power supply and when on land they normally operate using a 3-phase electrical supply- although it is possible, normally at additional cost, to convert the reefer to work on single phase.New or second handrefrigerated containersare very useful for the domestic market. They are often used by butchers, farmers, mushroom growers, plant nurseries, hospitals, paint and print suppliers etc. Whatever they are used for it is important to load the container properly so that they can maintain temperature efficiently.
The air is the cooled/heated to the required temperature in the condenser unit and then blown into the container. In reefer containers the air flows through the container from bottom to top. Often they have a “t-bar” floor so that the air can move underneath the product. There is also a maximum load height marked on the side walls which allows the air to circulate over the product. The temperature inside the refrigerated shipping container is displayed on an external control unit so that it can be checked at any time.

Inside of Refrigerated Container showing t-bar floor
Some refrigerated containers are also able to control humidity and some allow a controlled fresh air exchange through venting – particularly useful if they are transporting fruit as they can remove CO2 and ethylene.
When purchasing a second hand refrigerated container it is important to get it from a reliable supplier.The second hand container will then be refurbished and have a PTI (Pre Trip Inspection) by a qualified refrigeration engineer. They should be guaranteed for 3 months. In this way you can ensure that the quality of the unit you purchase is good and that you will have a machine capable of doing the job.
There are also the porthole containers which are insulated containers. They do not have an integral refrigeration unit and rely on a central cooling system on clip oncondenser units. As such the internal volume of the container is larger. In the domestic second hand units porthole containers, or indeedold refrigerated containersthat haveno viable condenser unit, are used asinsulated storage due to the thickness of the walls.