Pontiac 1955 Owner's Manual page 20

Weather Comfort
Control
VENTILATION SYSTEM-The ventilating panes in the door
windows, the duct type ventilators and the underseat heater are all
part of a controlled ventilation system.
Vent Panes—The ventilating panes
can be adjusted, by means of a crank
control, to any position to suit weather
conditions and provide circulation of
outside air in the car. They are also
useful in preventing fogging of the
windows, especially the windshield, in
cold weather.
Vent Ducts—Two "VENT" control knobs,
located on the instrument panel below the
centrally located glove box door are used to
control the amount of outside air entering
the car through the duct type ventilators in
the side kick pads. The amount that either
the right or left knob is pulled out will
regulate the amount of air entering the car from that particular duct.
The ducts are equipped with screens to prevent insects from entering
the car.
HEATER AND DEFROSTER-Even distribution of heated air is
accomplished through the use of a heater distribution manifold
running crosswise of the body under the front seat. Hood high air is
taken in through the intake directly below the windshield, heated
and discharged through the manifold toward the front and rear of the
car for equalized distribution by openings in the manifold under the
driver and front seat passenger.
Temperature Control—The "TEMP" control (lever on left of
steering column) is a thermostatic control similar in operation to the
thermostatic controls found on automatic oil or gas hot air furnaces.
To maintain the desired temperature inside the car the "TEMP"
control automatically regulates the flow of hot water to the heater.
This makes it unnecessary to change the setting of the "TEMP" lever
[17]