[0012]It is an object of the present invention to provide an air conditioner that achieves a reduction in
power consumption and cost and can improve safety.
[0015]The control element that controls the heater is disposed adjacently to the air passage and the
heat sink is disposed inside the air passage, and thus the control element can be cooled by an
airflow flowing through the air passage via the
heat sink. This eliminates the need to install a fan for cooling the control element, and thus
power consumption and cost can be reduced and the safety of the air conditioner can be improved.
[0016]Furthermore, in the longitudinal direction, the heat sink is disposed on the outside of the heater that is shorter than the blower fan, and thus the temperature rise of the control element due to heat
radiation of the heater can be suppressed. Moreover, air heated by heat exchange with the heat sink is sent out from an end portion of the air passage, and thus the efficiency of a heating operation can be improved. In addition, the heat sink is disposed in a
dead space between the blower fan and the heat exchanger, on the outside of the heater in the longitudinal direction, and thus the air conditioner can be prevented from increasing in size due to the installation of the heat sink.
[0017]Furthermore, in the present invention, preferably, in the air conditioner configured as above, the heater is formed by a PTC heater, and the control element is formed by a
triac element. According to this configuration, duty control of the PTC heater is performed by the triac element, and thus the occurrence of an
overcurrent at the start-up of the PTC heater is prevented.
[0019]According to this configuration, the circuit substrate is disposed in the cup-shaped substrate holder, and the control element mounted on the circuit substrate is brought into
close contact with the heat sink via the window portion. The molding material is filled in the substrate holder, so that the circuit substrate is molded and the control element disposed at the window portion is also molded. In a case where, during a cooling operation, low temperature air comes in contact with the heat sink and thus
dew condensation occurs in the substrate holder, since the molding material is filled, it is possible to prevent
dew condensation water from being deposited on the circuit substrate and the control element.
[0022]Furthermore, in the present invention, more preferably, in the air conditioner configured as above, the control element is fastened to the heat sink with a screw, and a groove portion into which the control element is fitted is recessed in the heat sink. According to this configuration, the control element is installed by being fitted into the groove portion of the heat sink and then is fastened thereto with a screw. At this time, the groove portion prevents the control element from being rotated due to the screw being firmly screwed down.