Porsche P-80 2005, Руководство пользователя

Страница: 41 / 108

Sports Cars System
Climate Control Systems Diagnosis & Repair
Page 3.7
After passing through the evaporator, the cooled airflow
splits. Some of this air is directed through the hot heater
core and is reheated, the rest bypasses. Outlet tempera-
ture is directly related to the percentage of air directed to
the heater core. A temperature flap controls how much air
is sent through the heater core.
If heating the incoming air is not desired, then the temper-
ature flap can be set to bypass all air around the heater
core and no reheat will take place. This occurs with the
Max. A/C setting.
Center Air Outlet Vent Shut-off Flaps – 911 Carrera/S
(997) & Boxster/S (987)
The increased vertical and horizontal adjustment range of
the vents and the separate left/right knurled wheel for the
center vent permit more specific adjustment of the air flow
than was previously possible. The vents should be closed
when a high level of heating is required and opened when
a high level of cooling is necessary.
Fresh Air Mode
Air can be drawn into the air distribution housing from two
sources: outside (fresh) air, and inside (recirculation) air.
When the fresh air mode is selected, outside air is drawn
into the vehicle from the intake air duct, located in the
plenum in front of the windshield. All outside air passes
through the particle filter.
As vehicle speed increases, ram air pressure increases
airflow. To compensate, the ram flap begins to close > 56
mph. The ram flap position is also influenced by blower
voltage.
Air Recirculation Mode
Depressing the recirculation switch on the A/C Control Unit
selects the recirculation mode. The recirculation mode
prevents outside air intake and increases the cooling effi-
ciency of the A/C. It also prevents unpleasant odors from
entering the vehicle interior.
When ambient temperature is > 26° C (79° F), the
processor automatically selects the recirculation mode
after 30 seconds of A/C operation to speed interior
cooling.
Manual air recirculation can be selected at any time to
prevent unpleasant odors from entering. The recirculation
mode is limited to 2 minutes max. if the A/C compressor
is OFF.
Defrost Mode
Depressing the defrost button on the Heating-A/C Control
Unit selects the defrost mode. This mode directs most
outlet air to the windshield. Air conditioning is engaged to
reduce humidity and to speed demisting.
Notes: