C
IRRUS
D
ESIGN
S
ECTION
7: A
IRPLANE
AND
S
YSTEMS
SR20
E
NVIRONMENTAL
S
YSTEM
P/N 11934-005
7-59
Environmental System
• N
OTE
•
To facilitate faster cabin cooling, prior to engine start leave the
cabin doors open for a short time to allow hot air to escape.
Standard cabin heating and ventilation is accomplished by supplying
conditioned air from the heat exchanger for heating and windshield defrost
and fresh outside air for ventilation. The environmental system consists of
a fresh air inlet in the lower RH cowl, a heat exchanger around the RH
engine exhaust muffler, an air mixing chamber, air ducting for distribution,
a distribution manifold, a windshield diffuser, crew and passenger air
vents, and associated plumbing, controls, actuators, wiring for system
flow-selection and temperature control.
An optional 3-speed blower fan is available to supplement airflow when
ram air may be inadequate such as during ground operation.
28 VDC for Environmental System Control Panel operation is supplied
through the 2-amp CABIN AIR CONTROL circuit breaker on MAIN BUS
1.
The optional Blower Fan is powered by 28 VDC supplied through a 15-amp
CABIN FAN circuit breaker on A/C BUS 2.
Serials w/ Optional Air Conditioning System:
The Air Conditioning System is designed to cool the cabin to desired
temperature settings and maintain comfortable humidity levels. The
system consists of an engine driven compressor, condenser assembly, and
evaporator assembly.
28 VDC for Air Conditioner Condenser operation is supplied through the
15-amp A/C COND circuit breaker on A/C BUS 1.
28 VDC for Air Conditioner Compressor operation is supplied through the
5-amp A/C COMPR circuit breaker on A/C BUS 2.
The airplane engine must be running for the air conditioner to operate.
Reissue A