100% ambient air environmental control system

An environmental control system comprising:

• a ram air circuit having a ram air duct, at least one ram heat exchanger arranged within the ram air duct, and a divider arranged within the ram air duct and extending parallel to a direction of ram air flow through the ram air duct, wherein a first portion of the at least one ram heat exchanger is arranged at a first side of the divider and a second portion of the at least one ram heat exchanger is arranged at a second side of the divider;
• a compression device including a compressor, a first turbine, and a second turbine operably coupled by a shaft, the compression device being configured to receive at least one of a first medium, a second medium, and a third medium, wherein an outlet of the first turbine and an outlet of the second turbine are both fluidly connected to only the second portion of the ram air duct at a location upstream from the second portion of the at least one ram heat exchanger;
• and
• an expansion device, separate from the compression device, the expansion device including another turbine, an inlet of the another turbine being fluidly connected to an outlet of the compressor relative to a flow of the second medium.