Pontiac 1953 Owners Service Manual page 21

" Venti-Heat"-Even distribution of heat is provided by the use of
a heater distribution manifold running crosswise of the body under
the front seat. Heated air entering the manifold is discharged through
two pairs of openings on the floor under the front seat; one pair
located beneath the driver, the other beneath the right hand front
seat passenger. Each pair of openings directs air to both the front
and the rear of car, giving four openings for equalized distribution
of air.
The '''TEMP'' control (knob at
right hand side of heater control
panel) is similar in operation to
the thermostatic controls found
on Qutomatic oil or gas hot air
furnaces. The heat source auto-
matically turns on and off as
the air TEMPERATURE in the
car falls below or above the
control setting.
Thus, once the ''TEMP'' knob is adjusted to produce a comfortable
temperature in the car, it is unnecessary to change the setting. This
is true even when the car has been standing in the cold because this
setting will produce as much heat as an extreme "HIGH" setting
to warm up the car.
The air that is heated and circulated through the car is outside
air drawn into the car; the Venti-Heat does not recirculate stale air.
The "AIR" control (knob at left hand side of heater control panel)
regulates the entry of outside air through the under seat unit and
defroster unit. Turning the knob to the "OFF" position merely closes
the air valves. Turning the knob to "NORMAL" or "DE-ICE" opens
the air valve. The "AIR" knob is always left in the "NORMAL" posi·
tion both in summer and winter. When de·icing the windshield turn
air knob to "DE-ICE".
For Offensive Odors Turn "AIR" Knob to " OFF" Position.
NOTE: To keep out offensive odors and exhaust gases when traveling in congested
traHic or when parked behind a car having its motor running turn the "AIR" knob
on the heater control panel to the "OFF" position and keep blower turned off. Exhaust
gases contain carbon monoxide.
"DE· ICE" position on "AIR" control knob forces heated outside
air through the windshield defroster and defroster ducts to clear the
windshield of ice. With the "AIR" CONTROL KNOB ON "DE-ICE"
position there is also a sufficient amount of warm air from the under-
seat heater to maintain the desired temperature inside the car.
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