Abstract: This invention relates to a compact heat exchanger-ventilation unit, for vehicles driven by internal-combustion engines which is compact and permits use of a narrow, low hood. The cooling air fan 1 has a diffuser and the resistance of the heat exchangers on the cooling air side is adapted to the delivery level of the cooling air fan 1. A refrigeration system condenser 7, charge air cooler 6, transmission oil cooler 4, motor coolant heat exchanger 3 and hydraulic oil cooler 5 are thus compactly arranged.

Abstract: A reciprocating internal combustion engine whose thermally loaded components are cooled by a cooling liquid. The internal combustion engine has at least one cylinder with piston and a cylinder head associated therewith having an exhaust duct, as well as at least one liquid/air heat exchanger, which receives cooling-air from a cooling fan.The cooling fan (2) has a diffuser (3) and the liquid/air heat exchanger (1) is adapted to operate at an elevated cooling-air pressure of the cooling fan (2). The pressure of the cooling-liquid system and/or the composition of the cooling liquid are selected such that the boiling point of the cooling liquid lies between 110.degree. and 130.degree. C., preferably around 125.degree. C. The exhaust duct (5) in the cylinder head (4) is substantially thermally isolated from nearby regions of the cylinder head.