Abstract: An apparatus, system and method for improving air entrainment and sound attenuation of gases being discharged from one or more outlet portions of an exhausting device using an acoustic wind band. The acoustical wind band helps improve entrainment of ambient environmental air with the exhaust gases being discharged from the exhausting device resulting in a tight plume of high velocity flow which improves the effective stack height of the exhausting device. This is achieved by positioning the sections of the acoustical wind band in spaced relation thus forming passages that allow outside ambient environmental air to flow into the acoustical wind band to mix with and dilute the exhausting gas. The sections may also be positioned extending upward and inward at an angle to further enhance the entrainment of ambient environmental air with the flow of exhaust gas from the gas exhaust device.

Abstract: An acoustic silencer nozzle for ventilation and exhaust fans. The nozzle provides at least two converging exhaust paths, each of which extend through an area that is adjacent acoustically absorbing media or resonating chambers. In this manner, the noise is reduced at the nozzle or outlet portion and provides a tight plume of high velocity discharge flow. Preferably, the nozzle has at least one opening that allows for ambient atmospheric air to mix with the exhaust gases at the outlet of the nozzle.