Prediction of performance criteria for passive heating ventilation and air conditioning silencers

Unwanted noise is generated by the operation of heating, ventilation, and air conditioning (HVAC) systems in large buildings. The unwanted noise can be reduced by installing a passive silencer in the HVAC system. The ability to predict the performance criteria (insertion loss, regenerated sound power, and pressure drop) associated with a passive silencer is of great importance to the HVAC engineer. The purpose of this thesis is to predict the performance criteria listed above. Empirically derived regression equations are provided which calculate the performance criteria associated with 2ft x 2ft cross sectional area rectangular passive silencers for various internal geometries using either fiberglass or mineral wool linings. The performance criteria predicted by the regression equations is compared with the measured data; also, results are provided which display the effect the internal geometries and lining materials have on passive silencers performance criteria