A system includes a first inlet providing a medium from a source and a compressing device arranged in communication with the first inlet. The compressing device includes a compressor configured to receive the medium and a turbine located downstream from the compressor. The system additionally includes at least one heat exchanger and an electric motor operably coupled to the compressor. The system is powered by mechanical power from the medium and by electrical power from the electric motor. The input power of the electric motor is less than or equal to 0.5 kilowatts per pounds per minute of medium compressed.