Self-contained refrigeration systems mounted on vehicles, trailers, or shipping containers, providing active temperature control independent of vehicle operation. TRUs include compressors, condensers, evaporators, controls, and power sources (typically diesel engines or electric standby connections). Modern TRUs offer precise temperature control, automated defrost cycles, telematics connectivity, and fuel efficiency features. Key specifications include cooling capacity (BTUs), temperature range capability, fuel consumption, noise levels, and refrigerant type. TRU selection considers cargo volume, insulation quality, typical ambient conditions, and operational duration. In South Africa, TRU reliability and fuel efficiency directly impact operational costs and service quality, making equipment selection a critical business decision. However, most TRUs are designed for European long-haul operations with minimal door openings and sea-level conditions, creating systematic under-performance in South African multi-stop urban delivery at altitude. Professional operators specify TRUs with altitude correction, oversized capacity for multi-stop duty cycles, and demand-based defrost rather than accepting supplier catalog offerings optimized for different operational contexts.
Engineering Context: For detailed TRU sizing calculations accounting for altitude, multi-stop thermal loads, and efficiency analysis, see our Technical Formulas Reference.
Related Terms: Reefer Vehicle, Mechanical Refrigeration, Defrost Cycle, High-Altitude Refrigeration, Variable Speed Compressor