Assembly of a heat exchanger

The system has evaporators (403, 406) for cooling flowing-air, and heating bodies (401, 402) for heating the air. The heating bodies and the evaporators are partially arranged one above the other in a perpendicular driving direction (404) of a motor vehicle. A beam is arranged in a floor of the vehicle and projected from the floor by the evaporators in a vehicle direction at an angle between 90 and 180 degrees. Another beam is arranged outwardly from the floor of the vehicle by the heating bodies in the vehicle direction at an angle between 0 and 90 degrees.