Patent Publication Number: US-10774845-B2

Title: Acoustic treatment for an indoor HVAC component

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is related to, and claims the priority benefit of, U.S. Provisional Patent Application Ser. No. 62/006,589 filed Jun. 2, 2014, the contents of which are hereby incorporated in their entirety into the present disclosure. 
    
    
     TECHNICAL FIELD OF THE DISCLOSED EMBODIMENTS 
     The presently disclosed embodiments generally relate to heating, ventilation, and air-conditioning (HVAC) systems, and more particularly, to an acoustic treatment for use with an HVAC system. 
     BACKGROUND OF THE DISCLOSED EMBODIMENTS 
     Fan coil units are now being constructed with axial fan technology rather than a forward curved blower system. Axial fan systems require a mounting deck with a means to slide the deck into the fan coil unit for support. A sheet metal inner liner provides the mounting structure for the axial fan. However, if this inner liner is composed entirely of sheet metal, there is potential that the sound and vibration from the fan system is not absorbed or dampened. Thus, there is a need to devise an “inner liner” that is more conducive to mitigation of sound from the fan coil unit. 
     Typically, forward curved blower systems are used within residential air handlers and furnaces. Over time, axial fan technology has been introduced to residential air handlers. Typically, axial fan system require a mounting deck that slidably engages with a support within the air handler. Typically, an inner liner provides the mounting structure for the axial fan system. When the inner liner is composed of sheet metal, sound and vibration produced by the axial fan system provide undesirable results. There is therefore a need to reduce the sound and vibration within the HVAC component using an axial fan system. 
     SUMMARY OF THE DISCLOSED EMBODIMENTS 
     In at least one embodiment, an acoustic treatment for an indoor HVAC component is provided having an inner liner and at least one aperture formed through the inner liner. An acoustic absorber is positioned adjacent the inner liner. A gap, including a width dimension, is formed between the inner liner and the acoustic absorber. 
     In at least one embodiment, an indoor HVAC component is provided having an enclosure including at least one wall, and a fan assembly disposed within the enclosure. An acoustic treatment is coupled to the at least one wall and positioned proximate to the fan assembly. The acoustic treatment includes an inner liner and at least one aperture formed through the inner liner. An acoustic absorber is positioned adjacent the inner liner. A gap, including a width dimension, is formed between the inner liner and the acoustic absorber. 
     In at least one embodiment, an HVAC system is provided including at least one indoor HVAC component having an enclosure including at least one wall, and a fan assembly disposed within the enclosure. An acoustic treatment is coupled to the at least one wall and positioned proximate to the fan assembly. The acoustic treatment includes an inner liner and at least one aperture formed through the inner liner. An acoustic absorber is positioned adjacent the inner liner. A gap, including a width dimension, is formed between the inner liner and the acoustic absorber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments and other features, advantages and disclosures contained herein, and the manner of attaining them, will become apparent and the present disclosure will be better understood by reference to the following description of various exemplary embodiments of the present disclosure taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a schematic cross-sectional view of an indoor HVAC component formed in accordance with an embodiment. 
         FIG. 2  is a schematic front view of an acoustic treatment for an indoor HVAC component. 
         FIG. 3  is a schematic cross-sectional side view of an acoustic treatment for an indoor HVAC component. 
         FIG. 4  is a schematic side view of an acoustic treatment for an indoor HVAC component. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS 
     For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended. 
       FIG. 1  illustrates an indoor HVAC component  100  having an enclosure  102  formed by at least one wall  104 . An axial fan  106  is positioned within the enclosure  102 . The axial fan  106  includes a motor and fan blades extending radially from the motor. In one embodiment, a stator may be positioned adjacent to the fan blades. 
     At least one acoustic treatment  120  is positioned along the at least one wall  104 . The acoustic treatment  120  is positioned proximate to the axial fan  106  and is configured to absorb noise from the axial fan  106 . In particular, the acoustic treatment  120  is configured such that the acoustic treatment  120  absorbs frequencies which are common to axial fans  106 . Such frequencies are typically not generated by other configurations of fans. Accordingly, the configuration of the acoustic treatment  120  is customized for axial fans  106 . 
     While the disclosed embodiments are discussed with respect to an indoor HVAC component  100 , it should be noted that the acoustic treatment  120  described herein may be utilized with other appliances having an axial fan, such as refrigerators or the like. Additionally, in at least one embodiment, the acoustic treatment described herein may be utilized with an appliance that does not include an axial fan. 
       FIG. 2  illustrates a front view of the acoustic treatment  120 . The acoustic treatment  120  includes an inner liner  122 . In at least one embodiment, the inner liner  122  is formed from metal, for example sheet metal. However, it should be appreciated that other materials may be used for the inner liner  122 , such as plastics and composites. The inner liner  122  is positioned adjacent the at least one wall  104  and is configured to face the enclosure  102  of the indoor HVAC component  100  so that the inner liner  122  is positioned proximate to the axial fan  106 . 
     In at least one embodiment, the inner liner  122  is not contiguous. Rather, the inner liner  122  includes a rail  130  formed therethrough. The rail  130  is configured to receive components of the indoor HVAC component  100 . For example, the axial fan  106  may be slid into the indoor HVAC component  100  on the rail  130  and mounted thereto. Additionally, components such as an electrical heater may be secured to the rail  130  for use within the indoor HVAC component  100 . 
     The inner liner  122  includes at least one aperture  132  extending therethrough. The at least one aperture  132  is configured to allow sound waves to pass through the inner liner  122 . In the illustrated embodiment, the apertures  132  are circular. In at least one embodiment, the apertures  132  may have any shape or size that optimizes the absorption of sound waves within the indoor HVAC component  100 . For example, the apertures  132  may be triangular, square, pentagonal, hexagonal, and/or any other suitable shape and size. Additionally, the apertures  132  are illustrated as being arranged in rows. In at least one embodiment, the apertures  132  may be formed in any arrangement that is configured to absorb sound. For example, the apertures  132  may be arranged in circles and/or any other suitable configuration. 
     As illustrated in  FIGS. 3 and 4 , the acoustic treatment  120  further includes an acoustic absorber  140  that is positioned between the inner liner  122  and the wall  104  of the indoor HVAC component  100 . The acoustic absorber  140  may be formed from any material capable of absorbing sound waves. In at least one embodiment, the sound absorber  140  is formed from foam and/or fiberglass. Sound waves passing though the apertures  132  in the inner liner  120  are absorbed by the acoustic absorber  140 . 
     A gap  142  is formed between the inner liner  122  and the acoustic absorber  140 . The gap  142  attenuates the sound waves as they pass from the apertures  132  in the inner liner  122  to the acoustic absorber  140 . The gap  142  has a width defined from the inner liner  122  to the acoustic absorber  140  that increases sound attenuation as the sound waves pass through the gap  142 . In one embodiment, the width of the gap  142  is less than approximately 15 millimeters. In one embodiment, the width  148  of the gap  142  is between approximately 4 and approximately 12 millimeters. In one embodiment, the width  148  of the gap  142  is between approximately 4 and approximately 6 millimeters. In one embodiment, the width  148  of the gap is approximately 6 millimeters. 
     It will therefore be appreciated that the disclosed embodiments provide an acoustic treatment that is tailored to an indoor HVAC component including an axial fan. Because axial fans operate at different frequencies than other fans, such an acoustic treatment has not been necessary in the past for air handlers that did not include an axial fan. The combination of the inner liner, the acoustic absorber, and the gap provides increased sound attenuation within the indoor HVAC component. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.