Aircraft environmental control systems having a single ram air inlet providing air to both cabin air compressors and associated heat exchangers are disclosed herein. In one embodiment, and environmental control system for use with an aircraft includes a ram air inlet, an air conditioning pack, and an associated heat exchanger. In this embodiment, the ram air inlet provides a first portion of air to the air conditioning pack, and a second portion of air to the associated heat exchanger. The first portion of air flows from the air conditioning pack and through the heat exchanger before flowing into an aircraft cabin. The second portion of air from the ram air inlet cools the first portion of air in the heat exchanger before exiting the aircraft through a ram air outlet. The inlet and outlet can be modulated on an optimized schedule to minimize the net drag of the ram system.