Mechanical noise design—Discrepancies between calculations and outcomes in the field

HVAC noise calculations that acoustical consultants typically perform utilize software that are mostly based on conceptual ASHRAE equations. Field measurements often indicate that the measured levels are sometimes close to those that are calculated, while at other times the discrepancies are greater. While conservative measures are taken to account for the discrepancies, this can potentially lead to overdesign, incurring additional costs that may not have been necessary. While considering every possible field factor is difficult, this study explores the identification of a few uncertainties that exist during design and field implementation.