What you will learn

• How the Sonic Series acoustic louvre SL4-20 provides airborne sound reduction for mechanical, HVAC and industrial applications within a 200mm system depth, achieving a Weighted Sound Reduction Index of Rw 20dB assessed to AS 1191:2002 (R2016) and rated to AS/NZS ISO 717.1:2004.
• The airflow performance of the SL4-20, including a 21% free open area, coefficient of discharge of 0.77 and Class 1 classification to AS/NZS 4740:2000, with pressure drop data across a range of operating velocities.
• How the SL4-20 balances acoustic attenuation, aerodynamic performance, and weather protection within a 200mm-deep single-blade configuration, providing higher sound reduction than shallower Sonic Series acoustic louvre models while maintaining airflow.
• Weather performance assessed in accordance with AS/NZS 4740:2000, including a Class C rain resistance classification and an average effectiveness of 0.865 across core velocities up to 3.5m/s.
• Construction details of the SL4-20 comprise a steel frame, steel front blade, perforated steel rear liner, and Rockwool acoustic infill, finished with a powder-coated finish in the nominated colour.
• Available customisation options for the SL4-20, including project-specific dimensions, colour finishes and integration with façade and plant screen applications.