After opening a new multi-family residential complex, the association was asked to perform a comprehensive survey of the sound from their HVAC systems. The survey sought to quantify the sound levels from every HVAC diffuser, grille, and register that served the residences and common spaces. The effort required access into over 250 residences typically measuring between 3 and 5 locations in each residence, and as many as 7 to 9 locations in penthouse residences. While the heat pump systems serving the residences were similar models, their capacities varied depending on the square footage and solar exposure of the residence. The variations in the sound levels of these systems and from the central ventilation were significant. This presentation will highlight what was learned from the survey.