An environmental control system (ECS) for an aircraft includes at least one cooling turbine, and a turbine bypass valve disposed fluidly upstream of the at least one cooling turbine. The turbine bypass valve is configured to direct a first portion of an ECS output airflow to a first air load at a first pressure via a first outlet passage, and direct a second portion of the ECS output airflow across a cooling turbine of the at least one cooling turbine and to a second air load at a second pressure lower than the first pressure for cooling thereof.