Subaru 2002 Impreza Service Manual page 371

HEATER SYSTEM
HVAC System (Heater, Ventilator and N C )
2. DESIGN FEATURES FOR EACH AIR FLOW MODE
1)
Ventilation (VENT) mode
0
The passage leading air from the evaporator to the ventilation outlet (VENT) is made straight to
reduce air flow resistance.
0
When the air temperature is necessary to be adjusted, heated air is blown at right angles against
the flow of cool air from the evaporator. This allows the airs to mix thoroughly.
(1) DEF VENT
HEAT
NF0163
(1 ) Evaporator
(2)
Heater core
2) Foot/face (BILEVEL) mode
0
Warm and cool air flows are created by structural means, namely, by forming sealing surface
for air toward leg area on the heated air passage side and that for air toward the ventilation outlet
(VENT) on the cooled air passage side.
To prevent an excessive difference in the temperature between the two air flows, a bypass pas-
sage is provided to allow part of heated air to flow toward the ventilation (VENT) outlet.
VENT
NF0164
(1 )
Evaporator
(2) Bypass passage
(3) Heater core
AC-7