31. The charge air cooling and the first locomotives to use this became known as Class 25 locomotives. 32. It combines water cooling and air cooling . 33. The advantages of water cooling over air cooling include water's higher specific heat capacity and thermal conductivity. 34. Forced-air cooling can approximately double the rating over the same size conductors used in a self-cooled system. 35. This position allowed both cylinders to protrude into the airflow, providing excellent air cooling for each cylinder. 36. Thus, SATA connectors and cables are easier to fit in closed spaces, and reduce obstructions to air cooling . 37. Above 15 W / cm 2 forced air cooling is required; liquid cooling if in a confined space. 38. Hence less need for air cooling . 39. Onroak and technical partners focused on the air cooling of the engine radiators and brakes and cockpit air conditioning. 40. Most " liquid-cooled " engines use some air cooling , with the intake stroke of air cooling the combustion chamber.