Patent attributes
A compressing device for use in an environmental control system includes at least one turbine configured to provide energy by expanding one or more medium. The one or more mediums provided at an outlet of the at least one turbine form a heat sink within the environmental control system. A compressor is configured to receive energy from the one or more mediums expanded across the at least one turbine. During a first mode of the compressing device, energy derived from a first medium of the one or more mediums is used to compress a second medium at the compressor and during a second mode of the compressing device, energy derived from both the first medium and a third medium of the one or more mediums is used to compress a second medium at the compressor.