Environmental System; Description And Operation - Cirrus SR22 Pilot Operating Handbook

Section 7 Cirrus Design
Airplane Description SR22

Environmental System

Cabin heating and ventilation is accomplished by supplying
conditioned air for heating and windshield defrost and fresh air for
ventilation. Ventilation air is provided by ducting ram air from air inlets
to eyeball outlets for each occupant. Each occupant can direct the
fresh air flow by positioning the nozzle or control flow rate from 'off' to
maximum by rotating the nozzle.
Heating is accomplished by mixing ram air from the fresh air inlets with
heated air from the heat exchanger and then distributing the
'conditioned' air to the occupants and/or the windshield diffuser. Air for
heating is supplied by an inlet in the engine compartment to a muff-
type heat exchanger surrounding the right engine exhaust muffler.
Conditioned air outlets for the forward occupants are directionally
controllable and are located beneath the instrument panel at each
position at knee level. Outlets for the rear occupants are at floor level.
The temperature, volume, and flow selection are regulated by
manipulation of the cabin temperature and cabin air selector knobs on
the lower right side of the instrument panel.
Serials 1602, 1821, 1840, 1863 and subsequent: An optional blower
fan and/or air conditioning system is available

Description and Operation

Serials 0002 thru 1601, 1603 thru 1820, 1822 thru 1839, 1841 thru
1862*
The environmental system consists of an air inlet in the upper RH
cowl, a heat exchanger around the RH engine exhaust muffler, two
fresh air inlets, located in each wing root leading edge, a hot air valve
located on the firewall, an air mixing plenum located behind the
instrument panel, a windshield diffuser, air ducting for distribution,
crew and passenger air vents, and required actuators for selecting
temperature and flow
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 shuts off airflow to
7-76 P/N 13772-001
Revision A10