Air conditioner and control method thereof

An air conditioner comprising:

• a cabinet including
• a front opening formed at a front surface of the cabinet, and
• a rear opening formed at a rear surface of the cabinet so that the front opening and the rear opening form an air flow passage inside the cabinet;
• a heat exchanger provided in the air flow passage inside the cabinet;
• a plurality of fans inside the cabinet and configured to guide air to pass through the heat exchanger;
• and
• a processor configured to control the plurality of fans so that
• in a cooling operation mode and a dehumidification operation mode, the plurality of fans are rotated in a first direction so that air is suctioned through the rear opening of the cabinet to flow through the air flow passage and pass through the heat exchanger, and the air is discharged through the front opening to an exterior of the cabinet, and
• in an automatic cleaning operation mode, the plurality of fans are rotated in a second direction, opposite to the first direction, until the automatic cleaning operation mode is completed, so that air is suctioned through the front opening of the cabinet to flow through the air flow passage and pass through the heat exchanger, and the air is discharged through the rear opening to the exterior of the cabinet,
• wherein in the automatic cleaning operation mode, the processor controls a rotation speed of a fan located at a bottom of the plurality of fans to be fastest among the plurality of fans, and controls rotation speeds of remaining fans among the plurality of fans located thereover to be sequentially slowed, such that a rotation speed of a fan among the remaining fans is slower than a rotation speed of another fan among the remaining fans located below the fan.