A room air conditioning system, comprising: a plurality of indoor units (10, 10A, 10B) to be installed on a ceiling; and a controller that causes the plurality of indoor units (10, 10A, 10B) to perform airflow control and temperature evenness control (ST4, ST7, ST8, ST14, ST17, ST18), wherein each of the plurality of indoor units (10, 10A, 10B) includes: an air conditioner main body whose lower surface (14a, 30a) has a periphery along which a plurality of blow-off openings are formed; a plurality of flaps (38, 38A, 38B) rotatably disposed in the respective blow-off openings, the flaps (38, 38A, 38B) being capable of independently changing vertical angles of airflows; and a human body sensor that detects whether a person is present below a corresponding one of the plurality of indoor units (10, 10A, 10B), wherein when at least one of the human body sensors in the plurality of indoor units (10, 10A, 10B) detects absence of a person with the airflow control being selected, the controller causes a corresponding one of the indoor units (10, 10A, 10B) that detects the absence to perform the temperature evenness control (ST4, ST7, ST8, ST14, ST17, ST18), characterized in that the plurality of flaps (38, 38A, 38B) include a first pair of flaps opposing each other and a second pair of flaps opposing each other, the first pair of flaps and the second pair of flaps being disposed perpendicularly to each other, and in that the controller is configured to perform the temperature evenness control (ST4, ST7, ST8, SST14, ST17, ST18) by sequentially performing: a first step of positioning, of the plurality of flaps (38, 38A, 38B), the first pair of flaps at an angle of a lowest location and the second pair of flaps at an angle of a middle location; a second step of positioning all of the plurality of flaps (38, 38A, 38B) at the angle of the lowest location; and a third step of positioning the first pair of flaps at the angle of the middle location and the second pair of flaps at the angle of the lowest location. a plurality of indoor units (10, 10A, 10B) to be installed on a ceiling; and a controller that causes the plurality of indoor units (10, 10A, 10B) to perform airflow control and temperature evenness control (ST4, ST7, ST8, ST14, ST17, ST18), wherein each of the plurality of indoor units (10, 10A, 10B) includes: an air conditioner main body whose lower surface (14a, 30a) has a periphery along which a plurality of blow-off openings are formed; a plurality of flaps (38, 38A, 38B) rotatably disposed in the respective blow-off openings, the flaps (38, 38A, 38B) being capable of independently changing vertical angles of airflows; and a human body sensor that detects whether a person is present below a corresponding one of the plurality of indoor units (10, 10A, 10B), an air conditioner main body whose lower surface (14a, 30a) has a periphery along which a plurality of blow-off openings are formed; a plurality of flaps (38, 38A, 38B) rotatably disposed in the respective blow-off openings, the flaps (38, 38A, 38B) being capable of independently changing vertical angles of airflows; and a human body sensor that detects whether a person is present below a corresponding one of the plurality of indoor units (10, 10A, 10B), wherein when at least one of the human body sensors in the plurality of indoor units (10, 10A, 10B) detects absence of a person with the airflow control being selected, the controller causes a corresponding one of the indoor units (10, 10A, 10B) that detects the absence to perform the temperature evenness control (ST4, ST7, ST8, ST14, ST17, ST18), characterized in that the plurality of flaps (38, 38A, 38B) include a first pair of flaps opposing each other and a second pair of flaps opposing each other, the first pair of flaps and the second pair of flaps being disposed perpendicularly to each other, and in that the controller is configured to perform the temperature evenness control (ST4, ST7, ST8, SST14, ST17, ST18) by sequentially performing: a first step of positioning, of the plurality of flaps (38, 38A, 38B), the first pair of flaps at an angle of a lowest location and the second pair of flaps at an angle of a middle location; a second step of positioning all of the plurality of flaps (38, 38A, 38B) at the angle of the lowest location; and a third step of positioning the first pair of flaps at the angle of the middle location and the second pair of flaps at the angle of the lowest location. a first step of positioning, of the plurality of flaps (38, 38A, 38B), the first pair of flaps at an angle of a lowest location and the second pair of flaps at an angle of a middle location; a second step of positioning all of the plurality of flaps (38, 38A, 38B) at the angle of the lowest location; and a third step of positioning the first pair of flaps at the angle of the middle location and the second pair of flaps at the angle of the lowest location.