An integrated environmental control system for an aircraft compartment and
aircraft power system comprises first and second air compressors, an
auxiliary power unit, and first and second environmental control systems.
The first and second compressors receive and compress airflow from the
aircraft exterior. The auxiliary power unit comprises a first shaft
rotatably mounting a power turbine, a third air compressor to compress
airflow from the aircraft exterior, and a first cooling turbine to cool
the airflow. Each environmental control system comprises a first heat
exchanger, a recycling heat exchanger, and a second shaft rotatably
mounting a fourth compressor and a second cooling turbine for compressing
and cooling the airflow. The first heat exchanger receives airflow from
the first, second, and third air compressors and forwards airflow to the
aircraft compartment. The recycling heat exchanger receives airflow from
the aircraft compartment and recirculates airflow back to the aircraft
compartment.