Patent attributes
A disclosed gas turbine engine includes a fan section delivering air into a compressor section. An environmental control system includes a higher pressure tap at a higher pressure location in the compressor section, and a lower pressure tap at a lower pressure location. The lower pressure tap communicates to a first passage leading to a downstream outlet, and having a second passage leading into a compressor section of a turbocompressor. The higher pressure tap leads into a turbine section of the turbocompressor such that air in the higher pressure tap drives the turbine section to in turn drive the compressor section of the turbocompressor. A combined outlet of the compressor section and the turbine section of the turbocompressor intermixes and passes downstream to be delivered to an aircraft use.