Specifications

7-80 Information Manual
Section 7 Cirrus Design
Airplane Description SR20
Cabin Air Selector
“Conditioned” air from the mixing plenum can be proportioned and
directed to the windshield or passengers by manipulating the cabin air
selector. The control is linked to a door at the outlet end of the mixing
plenum. Rotating the control full counterclockwise to the miniature
windshield shuts off airflow to the passenger air distribution system
and allows maximum airflow to the windshield diffuser. Rotating the
knob full clockwise to the seated person icon shuts off airflow to the
windshield diffuser and allows maximum airflow to the passenger air
distribution system. The control can be positioned to allow any
proportion of windshield and passenger air.
Conditioned air for the forward seats is routed to outlets under the
instrument panel at knee level. Conditioned air for the aft seats is
ducted to outlets beneath the forward seats near the door posts and
exits at floor level.
Cabin Heat Control
The amount of heated air allowed into the air mixing plenum is
controlled by rotating the Cabin Heat Control, located inboard of the
Cabin Air Selector. The control is mechanically linked to a door in a
heater box between the heater muff and the mixing plenum. Rotating
the control full counterclockwise (HEAT OFF) bypasses heated air
from the heater muff into the engine compartment. Rotating the control
clockwise opens the door in the heater box allowing heated air to enter
the mixing plenum.
Cabin Cooling Control
The amount of cooling air allowed into the air mixing plenum is
controlled by rotating the cabin cool control, located outboard of the
cabin air selector. The control is mechanically linked to a butterfly
valve at the fresh air entrance to the mixing plenum. Rotating the
control full counterclockwise shuts down cooling airflow to the mixing
plenum from the fresh air inlet in the right wing root. Rotating the
control clockwise opens the butterfly allowing fresh cooling air to enter
the mixing plenum. Rotating the knob to the full clockwise (COLD)
position provides maximum cooling airflow to the mixing plenum.
March 2010