Reefer Container

A refrigerated container, universally called a reefer, is an ISO standard intermodal container fitted with an integral refrigeration unit mounted in the front wall that circulates temperature-controlled air through the cargo space. Reefers maintain temperatures from around +12 °C for some fruits and vegetables down to −25 °C or lower for deep-frozen fish and meat, with precise humidity control for respiratory produce. The unit conforms to ISO 1496-2 dimensional standards so that it can be stacked and handled identically to dry cargo containers. Onboard electrical connections are provided in dedicated reefer sockets at a standard voltage — typically 380–460 V three-phase — located in container cell guides, on deck, or at dedicated reefer racks. The ship's generator capacity must be sized to serve all connected reefer containers simultaneously, and engineers monitor reefer power consumption, alarm logs, and supply voltage at regular rounds. Malfunctions are diagnosed using the container's control panel or remote monitoring system, and defective units are reported to the cargo officer so that temperature-sensitive cargo can be transferred before damage occurs. Pre-trip inspections of reefer containers before loading are required under many shipper contracts and carrier quality programmes.