GMC 2008 Acadia - Manual (Page 170)

For quicker cool down on hot days, do the following:
1. Open the windows to let hot air escape.
2. Select the vent mode.
3. Select the air conditioner.
4. Select the coolest temperature.
5. Select the highest fan speed.
6. Close the windows after the hot air has escaped.
7. Once the vehicle’s interior temperature is below
the outside temperature, select recirculation
mode for better cooling.
This helps to reduce the time it takes for the vehicle
to cool down. It also helps the system to operate
more efficiently.
Using recirculation for long periods of time may
cause the air inside of the vehicle to become too dry.
To prevent this from happening, after the inside of
the vehicle has cooled, turn the recirculation mode off.
The air conditioning system removes moisture from
the air, so you might notice a small amount of water
dripping underneath the front center and right rear
of the 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 the windshield. Turn the right knob
clockwise to select the defog or defrost mode.
-
(Defog): The defog mode is used to clear the
windows of fog or moisture and warm the passengers.
This mode directs air to the windshield, floor outlets,
and side window vents. When you select this mode,
the system turns off recirculation and runs the air
conditioning compressor unless the outside temperature
is less than 40°F (4°C). The recirculation mode
cannot be selected while in the defog mode. Do not
drive the vehicle until all the windows are clear.
0
(Defrost): The defrost mode is used to remove fog
or frost from the windshield more quickly. This mode
directs most of the air to the windshield and side window
vents and some to the floor vents. In this mode, the
system will automatically force outside air into your
vehicle. The recirculation mode cannot be selected while
in the defrost mode. The air conditioning compressor
will run automatically in this setting, unless the outside
temperature is less than 40°F (4°C). Do not drive
the vehicle until all the windows are clear.
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