Systems Guide

A318/A319/A320/A321
Professional
SYSTEMS
Systems guide
Vol
4
04-03-8
11 July 2018
VENTILATION
The ventilation of avionics is controlled by the Avionics Equipment Ventilation Controller (AEVC). It
provides cooling of the avionics compartments using two fans, a heat exchanger that uses the outside skin
of the aircraft to cool the air and an inlet and outlet valve. Only the automated mode is simulated, and
you can see the ventilation valve position on the CAB PRESS ECAM page. Battery, galley and toilet
ventilation is provided by fans that draws air from the cabin and vents it overboard via a vent in the
aircraft skin.
Do note that the AEVC is very loud and other sounds from the aircraft systems that are heard on other
aircraft types are not heard on the A320 series.
APU
GENERAL
The Auxiliary Power Unit provides:
• Bleed air for engine starting
• Bleed air for air conditioning
• Electrical power for all the buses
The APU can be used on the ground and in flight with the following limitations:
• 100% generator load up to 25,000 feet
• Full pneumatic and hydraulic pressure up to 20,000 feet
• Can be started using the battery up to 25,000 feet.
SYSTEM COMPONENTS
The APU consists of a gas turbine engine with an APU computer that manages the system. The air intake
uses an