Indoor unit of air conditioner

The utility model discloses an air conditioner indoor unit which comprises a shell, a heat exchanger and a fan assembly, the fan assembly comprises a motor, a fan, a first installation piece and a second installation piece, the first installation piece is provided with a plurality of first volute parts and at least one first installation part, and the first installation part is located between every two adjacent first volute parts; a plurality of through openings are formed in the second mounting piece, a plurality of second volute parts and at least one supporting part are arranged on the first surface of the second mounting piece, the supporting part protrudes out of the first surface, the interior of the supporting part is of a hollow structure, and a second mounting part is arranged on the supporting part; a first reinforcing rib is arranged on the second surface of the second mounting part, and the first surface and the second surface are arranged in a back-to-back manner. The structural strength require