Abstract: A refrigeration system for freight vehicles having inwardly open profiling for air ducting in the floor, the side walls and the doors, the profiling in the region of the vertical walls and doors being formed of vertically extending grooves or channels. In order to ensure uniform supply of cooling air to the grooves or channels of the vertically extending profiling and to ensure uniform discharge of the cooling air in the region of the lower ends of the grooves or channels independently of the loading condition, each of the side walls has at least one lower, preferably one lower and one upper, substantially horizontally extending air ducting channel, the lower air ducting channel being arranged at a spacing from the floor, and the vertical profiling discharges into the air ducting channels.