Abstract: The current invention is device for lowering the air velocity and inherent noise of high-speed air released from a closed system, comprising a straight pipe module with an outer tube and a concentric inner tube creating an annular space therebetween. The inner tube has interior fins at the inlet, which initiate rotation in an airflow directed therethrough, and interior fins at the outlet, which arrest the airflow rotation. Perforations along the length of the inner tube, from inlet fins to outlet fins, permit the release of a turbulent outer zone of the airflow, permitting the high velocity core of the airflow to expand and slow, reducing the noise of the airflow.