Acoustic Window (Top-hung Type)

The upper level is top hung window for ventilation while the lower level is fixed glazing or fixed window for lighting only. A horizontal fin projecting out from the bottom of the top hung window is needed to screen off the noise from entering into the room through the opened top hung window. As noise can be transmitted into the room through single or multiple reflections at the window pane and horizontal fin, absorbent may be applied on the reflecting surfaces to enhance noise reduction effectiveness. Noise reduction depends very much on the aspect ratio of window height to fin depth. In general, a reduction of 5 dB(A) can be achieved with an aspect ratio of about 0.6.