Heating - Porsche 911 turbo Owner's Manual

Automatically
Regulated Air
Conditioning System
TVARNING
Familiarize
yourself thoroughly with
the
proper use and
function
oT
the
ventila-
tion/heating. defoggingidefrosting and
the
air conditioning
system.
l
For safe
driving
it
is
extremely
important
Ihal
you follow the
operating
instructions
in
this manual.
lT
in
doubt, consult
with
your
Porsche dealer.
i.
Maximum hêating output and fasi defrosl
I
ing can be obtainèd only after the
èngine
I
has
reached normal
operâting tempera-
IUre.
Function:
Air
for
heating
and
ventilation
is
drawn
in
through
the air intake in the rear deck lid
by
the engine
fan. Air for heating
is then diverted
by
an electric fan
and sent to the left and right
heat
exchangers
and then
on to the
heater
through valve systems, controlled by
differen-
tial pressure, in
the leït and right healing
sec-
tions. The purpose of the differential
pressure
control system
is to
allow heated air
to
pass
Torward
freely in heating mode.
lf
hot air is not
required
in the passenger compartment,
the
valve
boxes allow hot air
to
exhaust into
the
wheel housings. ln the heater, lresh air enter-
ing in front ol the windshield is
first
mixed with
recirculating air
that
enters
the
system
in
the
middle
of
the footwell. Both openings
have
shutoff valves; the fresh air valve is
actuated
56
by an electric motor and
the
recirculating
air
valve opens or closes depending on the pres-
sure within the
heater.
The cold
air
is
then
divided into two streams and enters the intake
housing in Iront
of
the fans on
the
right
and
left
sides.
The hot air
sections bringing
air
from the
engine
also open into this
intake
housing.
A
temperature mixing
valve
regu-
lates these hot and cold
air
streams
before
they are mixed in a fan. After passing
through
the right and left
fans, the
mixed air is
fed
into
a pressure channel from which air ducts
lead
to
the
vents.
Note:
To ensure proper
air
intake,
the fresh
air
inlet behind the
front
hood must be
kept
lree
ol
snow and ice in the
winter.
Operation:
The
automatic
heating system
regulates
temperature inside
the car by
means
oT
the
temperature sensor
(1
).
The
interior temperature
set
on
the
tempera-
ture selector (5) is
kept constant even if
cli-
matic conditions change.
However, the selected temperature cannot
be
lower than
the
current outside temperature.
Air distribution for the top and bottom vents
is
controlled separately
with two
slide
controls
(4), on above the other.
The upper slide
(4)
controls
the
amount
of air
emerging through
the
defroster
vents and
center vents.
At
the
extreme left position, the windshield
vents
are
closed
and
the
center
and side vents
are
open.
At the
extreme right position,
air
can
emerge from the windshield vents and
the
centre and side vents. The
amount
of
air
emerging
from
the
centre and side vents
is
determined by opening and closing the
vents
themselves.
The lower
slide
(4) controls air flow into
the
lootwells (open to the
right,
closed
to
the
left).
The two slides can be set, independently
of
one
another.
The
center and side vents can
be
opened
and
closed
with
the
knurled
wheels
beside
each vent.
Knurled
knob
up
- vent
closed
Knurled knob
down - vent
open.
The vanes can
be
moved
to deflect air in
the
desired direction.
Fan Switch (3)
The fan speed can be controlled with a
rotary
switch (3) which has 5
click stops.
At the "0"
setling the fan
runs
at
minimum speed.
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