The National Elevator Industry, Inc. (N.E.I.I.) has established industry performance standard guidelines for equipment airborne sound levels at multiple system locations and operational modes.
International Building Code (I.B.C), H.U.D, A.I.A., and others have established standards and guidelines for the architectural design and construction details related to sound ratings of wall and floor/ceiling assemblies to contain the equipment sounds in the machine room.
Beyond a few basic requirements for equipment isolation, what isn’t addressed are the structure-borne sound paths, which often are the true root of equipment sound disturbances. Each structure-born migration point magnifies the sound over larger surface areas. The occupied side of a hydraulic elevator machine room wall essentially acts like a flat panel speaker and the overhead traction systems machine room floor reacts much like drum skin, amplifying the sounds into the hoistway.
Influences of a buildings design and construction on equipment operational sound migration are difficult to impossible to predict. Taking a proactive treatment approach of the most common sound migration points will greatly reduce the possibility of elevator equipment sound disturbance complaints, ultimately saving repeated service calls and most importantly customer relations.
As a general reference, the speed of sound travel is through air at 1,200 ft./sec., concrete 11,000 ft./sec., and steel 19,000 ft./sec. This shows the significance and importance in reducing the elevator systems generated sound energy before it becomes a structure-borne sound.
Understanding and Controlling Elevator Noise 