Abstract: A compressor muffler (100) for a refrigeration system is provided with an array of Helmholtz resonators (130, 230, 330) formed along an inner surface of a muffler chamber (110) of the muffler.

Abstract: A compressor muffler (100) for a refrigeration system is provided with an array of Helmholtz resonators (130, 230, 330) formed along an inner surface of a muffler chamber (110) of the muffler.

Abstract: In a residential furnace having a layered insulation material on the inner walls of the heat exchanger compartment, the inner aluminum foil layer has a plurality of holes formed therein in order to allow for the outer layer to absorb the sound within the heat exchanger compartment and thereby reduce the noise emanating from the furnace. Both the density and size of the holes are optimized to maximize the sound absorption performance over the particular frequency ranges that are characteristic of the furnace.

Abstract: In a residential furnace having a layered insulation material on the inner walls of the heat exchanger compartment, the inner aluminum foil layer has a plurality of holes formed therein in order to allow for the outer layer to absorb the sound within the heat exchanger compartment and thereby reduce the noise emanating from the furnace. Both the density and size of the holes are optimized to maximize the sound absorption performance over the particular frequency ranges that are characteristic of the furnace.

Abstract: A sound absorbing light fixture (42) installed in a surface system, such as an elevator ceiling system (40), of an enclosed interior, such as the interior (32) of an elevator cab (32) is presented. The light fixture (42) comprises a frame (46) disposed in fixed relationship to the surface system, the frame (46) having an interior rear surface and interior side surfaces extending outwardly from the rear surface to define a cavity (50). A light source (48) is supported by the frame (46) within the cavity (50). Additionally, a light diffuser (44) is disposed in fixed relationship to a front portion of the frame (46) between the light source (48) and the enclosed interior. The installed light fixture (42) enhances a sound absorption coefficient, e.g., above 0.6, of the surface system for a predetermined frequency range of sound energy, e.g., 300-600 Hz.

Abstract: A computer controlled method for predicting acoustical properties for a generally homogeneous porous material includes providing at least one prediction model for determining one or more acoustical properties of homogeneous porous materials, providing a selected prediction model for use in predicting acoustical properties for the generally homogeneous porous material, and providing an input set of at least microstructural parameters corresponding to the selection model. One or more macroscopic properties for the homogeneous porous material are determined based on the input set of the microstructural parameters and acoustical properties for the homogeneous porous material are generated as a function of the one or more macroscopic properties and the selected prediction model.