Section 22: HEATING AND AIR CONDITIONING
PA1553
5
1. HEATING AND AIR CONDITIONING
The vehicle interior is pressurized by its Heating,
Ventilation and Air Conditioning (HVAC) system.
Two HVAC systems are available: Small HVAC
System and Central HVAC System. The vehicle
interior should always be slightly pressurized to
prevent dust and moisture from entering. If the
vehicle is equipped with a Central HVAC
System; air flow and controls divide the vehicle
into two areas: driver’s area and cabin area.
Each area has its own fresh air, returning air
and discharge air ducting; exhaust is mainly
done through normal air-tightness losses.
2. AIR CIRCULATION WITH CENTRAL
HVAC SYSTEM
2.1 DRIVER’S AREA
Fresh air is taken from a plenum behind the
front bumper and enters the mixing box through
an ON/OFF damper. Returning air is taken
through the right console into the mixing box.
Mixed air goes through cooling and heating
coils, fans and discharge ducts.
Both right and left discharge ducts defrost one
half of the windshield. The driver can also divert
his air flow to the dashboard, from which he can
direct vent to his upper body with adjustable
HVAC register and to his feet with the
appropriate button (see figure 1 and Owner’s
manual)
FIGURE 1: DRIVER’S AIR CIRCULATION 22171
2.2 CABIN AREA
Fresh air enters the vehicle on the L.H. side,
through the recirculation damper located inside
the evaporator compartment door (Fig. 2). The
damper can be fully opened for normal operation
or closed for extreme weather or highly polluted
areas (Refer to the Owner's Manual for more
details). The recirculation REC button is located
on the HVAC control module. Press down the
button to partially close the fresh air damper.
Return air is drawn from inside the vehicle
through a wire mesh opening in the floor located
amidships on L.H. side of vehicle (Fig. 3).
FIGURE 2: CABIN AREA RECIRCULATION DAMPER22339
A double blower fan unit, which is activated by the
evaporator motor, draws mixed air through an air
filter, cooling and heating coils, then forces this air
in the ventilation ducts along the walls, and finally
exhausts it just below side windows.
3. AIR CIRCULATION WITH SMALL HVAC
SYSTEM
Fresh air is taken from a plenum behind the
front bumper and enters the mixing box through
an adjustable damper. Returning air is taken
through the right console into the mixing box.
The recirculation REC button is located on the
HVAC control module (Figure 4). Mixed air goes
through cooling and heating coils, fans and
discharge ducts.
Both right and left discharge ducts defrost/defog
one half of the windshield. The driver can divert
his air flow to the dashboard, from which he can
direct vent to his upper body with adjustable
HVAC register and to his feet with the
appropriate button (see figure 1 and Owner’s
manual).