Air conditioner

An air conditioner comprising:

• an indoor unit including an indoor heat exchanger, an indoor unit fan including a fan motor, and a static pressure sensor configured to detect a static pressure of air blown out from the indoor unit fan;
• and
• a controller configured to control the fan motor,
• wherein the controller uses a static pressure value detected by the static pressure sensor and an air volume of conditioned air blown out from the indoor unit required by a user to determine a first fan rotation speed, which is a rotation speed of the indoor unit fan that implements the air volume,
• when the determined first fan rotation speed is not a prohibited rotation speed at which resonance occurs in the indoor unit, the controller controls the fan motor so that the indoor unit fan rotates at the first fan rotation speed,
• when the determined first fan rotation speed is the prohibited rotation speed, the controller controls the fan motor so that the indoor unit fan rotates at a second fan rotation speed different from the first fan rotation speed,
• the controller sets the second fan rotation speed to a rotation speed close to the first fan rotation speed and higher than the prohibited rotation speed when the first fan rotation speed is the prohibited rotation speed and the air volume used to determine the first fan rotation speed is larger than an air volume before the first fan rotation speed, and
• the controller sets the second fan rotation speed to a rotation speed close to the first fan rotation speed and lower than the prohibited rotation speed when the air volume used to determine the first fan rotation speed is smaller than the air volume before the first fan rotation speed.