Nomenclature
Air cycle systems can be identified by the type of air cycle machine.
The types of air cycle machines may be identified as:
- Simple cycle consisting of a turbine and fan on a common shaft
- Two-wheel bootstrap consisting of a turbine and compressor on a common shaft
- Three-wheel consisting of a turbine, compressor, and fan on a common shaft
- Four-wheel/dual-spool consisting of a two turbines, a compressor, and a fan on a common shaft
The term air conditioning pack or A/C pack is used differently by different sources. Boeing, Airbus, Embraer, Bombardier and Lockheed use the term as an abbreviation of package, applied to both pneumatic and non-pneumatic systems. At least one business jet supplier uses the term PAC instead on their systems control panels, said to be an abbreviation for pneumatic air conditioning. Supposedly, PACK can also be an acronym for pneumatic air cycle kit, however, this abbreviation is not used by the major manufacturers above.
Read more about this topic: Air Cycle Machine