An environmental control system of an aircraft includes a ram air circuit with a ram air shell having at least one heat exchanger positioned therein, a dehumidification system arranged in fluid communication with the ram air circuit, a compression device arranged in fluid communication with the ram air circuit and the at least one dehumidification system, and an expansion device arranged in fluid communication with the ram air circuit. At least one of the compression device and the expansion device is selectively operable to supplement the ram air within the ram air circuit to meet a demand of the aircraft.