Chevrolet 1970 Owner's Manual page 30

"BI·LEVEL" - Outside air is passed
through the system and discharged
from both the upper and lower out-
lets. This position is recommended for
sunny cooler weather where warm air
is required on the feet with cooler air
above to provide comfortable breath
level. Temperature may be adjusted
as desired.
NOTE: This position wll/ clear fogged
windows rapidly due to the dehumidifying
• effect of the cooling coils when the outside
temperature Is above 30°F.
"VENT" - Air flow and temperature
control are the same as "Bi-Level"
except that the compressor is off. This
position is provided for ,cool to moder-
ate weather when refrigeration is not
required.
"HEATER" - Outside air is delivered
throughth~ lower outlets. Tempera-
ture may be adjusted as required. This
position is recommended for most
winter driving.
"DE·FOG" - Outside air is delivered
from ' the lower outlet and the de-
froster duct to provide comfort and
keep the windshield clear under low
27
fogging conditions.
Operating tip: When driving in snow,
if defog or deice is not required to keep
the windshield from fogging, it is
recommended that the "Heater" posi-
tion be used. This keeps the wind-
shield cold so that snow will not stick
and melt and will provide a cleaner
view.
"DE·ICE" - Outside air is delivered
through .' the defroster outlets only.
Temperature and blower speeds may
be adjusted as required. This position
is recommended for conditions of
severe fogging and icing only.