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9.7.1 The heater core
g
An air/water exchanger
(uses engine cooling liquid energy)
g
Increases the cabin temperature
g
Demists & defrosts the glasses
9.7.2 The PTC
PTC stands for Positive Temperature Coefficient
PTC’s are self regulated electric heaters used
complementary to the heater core
Located mostly after the heater core or sometimes
in ducts (feet heater)
PTC’s have been introduced on climate control sys-
tems to compensate a lack of heat on high efficiency
engines.
Different types
g
Relay controlled or smart devices controlled via a
digital communication line (Lin Bus)
9.7 Heating
This is the primary role of air conditioning. All vehicles
are fitted with heating systems.
The engine cooling liquid is traditionally used as the
energy source for heating purposes.
Part of the heat produced by the engine is channelled
to the cabin via the heating radiator.
An additional electric heating device is sometimes
mounted on the system to provide additional heat in
some transient phases.
The heating components
are located inside the HVAC
after the blower
9. The Heating
Ventilation and
Air Conditioning
unit (HVAC)
28
Heater core
PTC