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Heating and Air Conditioning
Climatronic regulation behaviour
Pressing the “ON/OFF” button on the 2C-Climatronic
control unit activates the automatic climate control.
Since the occupants are exposed very quickly to the
outside temperature conditions when the roof is
opened, the automatic switch-over of the control logic
from coupé to cabriolet has to be very fast. When
closing the roof, the change-over of the control logic
to coupé mode is more gradual.
In cabriolet mode, there is no airflow regulation nor
automatic cold air functions. The inside temperature
sensor value for regulation in cooling mode
corresponds with the outside temperature. In heating
mode, the control value is calculated proportionally
from the value measured by the inside temperature
sensor and the outside temperature.
The settings that are present upon the respective
switch-over from cabriolet or coupé mode are stored
by the 2C-Climatronic system. When the system
returns to this operating mode, the stored values are
applied again.
Air distribution in heating mode
To create a feeling of warmth when the outside
temperature is low and the roof is open, the heated
air is almost exclusively supplied via the footwell and
the passenger vents because the windscreen cannot
fog in cabriolet mode. As the speed of the car
increases, the passenger vents supply a greater
amount of air compared with the footwell vents. This is
because there would otherwise be over-proportional
heating of the footwell due to the climate conditions
inside the car in cabriolet mode (back pressure).
The air is only supplied to the defrost vents in
automatic air-conditioning mode when the outside
temperature is very low.
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