Buick LaCrosse Owner's Manual page 201

Keep all outlets open whenever
possible for best system
performance.
Keep the path under all seats
clear of objects to help circulate
the air inside the vehicle more
effectively.
Use of non-GM approved hood
deflectors can adversely affect
the performance of the system.
Clear away any ice, snow, or leaves
from the air intake at the base of the
windshield that can block the flow of
air into the vehicle.
The filter removes dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.
The filter should be replaced as part
of routine scheduled maintenance.
See
for replacement intervals.
For more information, see your
dealer.
This vehicle may have the new
environmentally friendly refrigerant,
R1234yf. This refrigerant has a
significantly reduced global warming
impact on the environment,
compared to the traditional
automotive refrigerant, R-134a. All
vehicles have a label underhood
that identifies the refrigerant used in
the vehicle.
The refrigerant system should only
be serviced by trained and certified
technicians. The air conditioning
evaporator should never be repaired
or replaced by one from a salvage
vehicle. It should only be replaced
by a new evaporator to ensure
proper and safe operation.
During service, all refrigerants
should be reclaimed with proper
equipment. Venting refrigerants
directly to the atmosphere is harmful
to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite,
or other health-based concerns.