Avionics cooling capacity of the F-15 Environmental Control System is being increased significantly. This increase is provided by integration of a high pressure water separator (HPWS) in place of the present low pressure water separator.Avionics cooling capacity of the present ECS is limited by its cooling air flow and supply temperature capabilities. Maximum flow is determined by the nozzle area of the cooling turbine. Minimum supply temperature is established so the air contains no liquid water. This temperature depends on the water removal capability of the low pressure water separator.The new HPWS removes more water from moist air than the present system. This allows colder, dry air to be supplied for avionics cooling. With colder supply air, less flow is needed to cool the same avionics. Since the system can provide the same flow with either water separator system, more avionics can be cooled by incorporating the HPWS.