Abstract: An air diffuser 10 is provided which comprises a motor 54, an airflow control element 60 and a transmission between the motor 54 and the airflow control element 60 whereby, when the motor 54 is activated, the control element 60 is displaced either in the direction which allows airflow to increase or in the direction which decreases airflow and wherein the motor 54 is a stepping motor. The motor 54 is mounted on a stationary support structure 22, 26 on a side of the control element 60, opposite from the supply of air to the diffuser 10.