Reefer Unit

A reefer unit, short for refrigeration unit, is the mechanical cooling system mounted on a trailer, truck body, or container that provides temperature control for the transportation of perishable and temperature-sensitive goods. The unit operates independently from the truck's main engine and typically runs on its own diesel engine, though electric standby and hybrid models are increasingly available.

The primary components of a reefer unit include a diesel engine or electric motor, a compressor, a condenser, an evaporator, and a microprocessor controller that maintains the set temperature by cycling the refrigeration components on and off. Modern reefer units can maintain temperatures ranging from -20 degrees Fahrenheit for frozen products up to +70 degrees Fahrenheit for commodities requiring only climate control, with temperature accuracy within plus or minus one degree.

Leading reefer unit manufacturers include Carrier Transicold, Thermo King, and Zanotti. Units require regular maintenance including oil changes, belt replacements, coolant checks, and calibration of temperature sensors. A reefer unit failure during transit can jeopardize an entire load of perishable goods worth tens of thousands of dollars, making preventive maintenance and real-time temperature monitoring essential for refrigerated carriers.