Chevrolet Impala 2007 Impala Owner's Manual page 169

Using these settings together for long periods of
time may cause the air inside of your vehicle
to become too dry. To prevent this from
happening, after the air inside of your vehicle has
cooled, turn the recirculation mode off.
The air conditioning system removes moisture
from the air, so you may sometimes notice a small
amount of water dripping underneath your
vehicle while idling or after turning off the engine.
This is normal.
Defogging and Defrosting
Fog on the inside of the windows is a result of high
humidity (moisture) condensing on the cool window
glass. This can be minimized if the climate control
system is used properly. There are two modes to
clear fog or frost from your windshield. Use the
defog mode to clear the windows of fog or moisture
and warm the passengers. Use the defrost mode to
remove fog or frost from the windshield more
quickly.
Do not drive the vehicle until all the windows
are clear.
Turn the right knob clockwise to select the defog
or defrost mode.
-
(Defog): This mode directs air equally to the
windshield and the floor outlets. When defog
is selected, the system turns off recirculation and
runs the air conditioning compressor unless
the outside temperature is below 40°F (4°C).
0
(Defrost): This mode directs most of the air to
the windshield with some air to the side window
vents and to the floor vents. When defrost is
selected, the system will automatically force outside
air into the vehicle. The air conditioning compressor
will run automatically in this setting, unless the
outside temperature is below 40°F (4°C).
169