The aircraft cabin and cockpit are conditioned environments with the temperature controls being capable of use in both an automatic and manual fashion.
Basically the system operates by tapping hot bleed air from the engines and conditioning it through an ACM which is located on the co-pilot side of the nose baggage area.
Aircon temperature controls mounted below the co-pilots control column
This temperature regulated conditioned air, is then ducted through to the cabin and cockpit areas to provide a comfortable, pressurised environment for all occupants.
The pilot can select either left, right or both engines for the source of bleed air through the PRESS SOURCE selector switch mounted on the lower section of the centre pedestal.
Pressurisation source selector
The cabin is also capable of being supplied with ambient airflow should the ACM fail. This will require the aircraft to be operated unpressurised however.
Note: The aircraft will still operate perfectly well whilst unpressurised, however engine fuel flows will increase considerably due to the low operating altitudes required.