Open:
-This configuration is used if warm ambient conditions exist while the aircraft is on the ground.
-Outside air is drawn through the open inlet valve by the blower fan where it then passes around the avionics equipment.
-The extract fan then pulls the heated air and expels it out through the fully open extract valve.
-Avionics compartment air does not pass through the aircraft skin heat exchanger or the cargo under floor.
Intermediate:
-This configuration is used if warm ambient conditions exist during flight (airborne or thrust levers placed to a takeoff position while on the ground).
-The configuration is exactly the same as the closed configuration except that a small internal flap within the extract valve opens to expel some of the heated avionics compartment air overboard.
Closed:
-This configuration is used mostly during flight or if cold ambient conditions exist while the aircraft is on the ground.
-Avionics compartment air is cooled via an aircraft skin heat exchanger; air is circulated by the blower and extract fans.
-The inlet and extract valves remain closed.
-Air is expelled through the cargo under floor and out through the outflow valve.
A G00g1e search for "Quizlet A320 Air Systems mrdeerwood" found a text description, does my picture (incorporating a table of the thre possible heat sinks assist?
