Patent Publication Number: US-2022228770-A1

Title: Line of sight blocking grille assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/017,705, filed Jun. 25, 2018, entitled “LINE OF SIGHT BLOCKING GRILLE ASSEMBLY,” which claims priority from and the benefit of U.S. Provisional Patent Application No. 62/663,740, filed Apr. 27, 2018, entitled “LINE OF SIGHT BLOCKING GRILLE ASSEMBLY,” the disclosures of which are hereby incorporated by reference in their entireties for all purposes. 
    
    
     BACKGROUND 
     The present disclosure relates generally to a grille assembly and, more particularly, to an air grille assembly for an air duct of a heating, ventilation, and air conditioning (HVAC) system. 
     A wide range of applications exist for HVAC systems. For example, residential, light commercial, commercial, and industrial systems are used to control temperatures and air quality in residences and buildings. HVAC systems include ducts that guide airflow. Access into and out of these ducts is often provided via air grille assemblies. As an example, air return ducts remove air from a room and return the air to the HVAC system. Recycling the air through the air return duct maintains pressure within the building or home during operation of the HVAC system. The source air of the air removed from the room often includes airborne particulates, such as pollen, dust, and other airborne debris, that may damage the HVAC system. Accordingly, air grille assemblies are positioned at an opening of the air return duct or a plenum positioned upstream of the air return duct to remove large airborne debris (e.g., a balloon) and conceal the air return duct. In certain HVAC systems, the air grille assemblies may include a filter frame having a filter that removes the airborne particulates from the air before returning the air to an HVAC unit of the HVAC system. Air grille assemblies may also be used with different ducts and components of an HVAC system. Such air grille assemblies are typically located on a wall, ceiling, or floor of a room. Therefore, the air grille assemblies are generally visible to a person. It should be noted that air grille assemblies may also be utilized in conjunction with other features, such as dampers, to provide products, such as registers for use in HVAC systems. Other grille assemblies may be employed in different systems to facilitate, guide, or manage flow. SUMMARY 
     A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below. 
     In accordance with a first embodiment, a grille assembly having a housing including a corridor between a first end and a second end of the housing. The housing may be fluidly couple with a duct. The grille assembly also includes a core disposed within the corridor and having a plurality of blades that may guide fluid flow through the housing and a first portion of the plurality of blades slanted in a first direction at a first non-perpendicular angle relative to a corridor axis. The first portion of the plurality of blades are spaced relative to one another to form a first plurality of channels that partially pass through the housing. The grille assembly also includes a second portion of the plurality of blades slanted in a second direction that is substantially opposite the first direction at a second non-perpendicular angle relative to the corridor axis. The second portion of the plurality of blades are spaced relative to one another to form a second plurality of channels that partially pass through the housing and the first and second plurality of channels are arranged such that a line of sight from the first end to the second end of the housing is obstructed. 
     In accordance with a second embodiment, a grille assembly having a housing including a corridor extending from a first end portion to a second end portion of the housing and a core disposed within the housing. The core including a first core unit having a first plurality of blades that are each spaced apart relative to one another along a length of the first core and slanted in a first direction at a first angle relative to a corridor axis and a second core unit including a second plurality of blades that are each spaced apart relative to one another along a length of the second core unit and slanted in a second direction at a second angle relative to the corridor axis. The second core unit is positioned relative to the first core unit such that the first and second plurality of blades form a plurality of channels extending from an inlet disposed in the first core unit to an outlet disposed in the second core unit and the plurality of channels are deviated such that a line of sight the first end portion to the second end portion via the corridor is obstructed. 
     In accordance with a third embodiment, a grille assembly including a first core unit having a first plurality of blades. Each blade of the first plurality of blades is slanted in a first direction at a first angle relative to a corridor axis of the grille assembly. The grill assembly also includes a second core unit including a second plurality of blades, each blade of the second plurality of blades is slanted in a second direction at a second angle relative to the corridor axis. The second direction is substantially opposite the first directions, and the second core unit is positioned adjacent the first core unit such that a first end of each blade of the second plurality of blades is aligned with a second end of a respective blade of the first plurality of blades. The grille assembly also includes a channel extending from an inlet disposed in the first core unit to an outlet disposed in the second core unit. Each blade of the first and second plurality of blades are spaced apart relative to one another along the corridor axis to form the channel, and a line of sight from an inlet to an outlet of the channel is occluded. 
    
    
     
       DRAWINGS 
         FIG. 1  is a perspective view a heating, ventilating, and air conditioning (HVAC) system for building environmental management, in accordance with embodiments described herein; 
         FIG. 2  is a perspective view of the packaged HVAC unit of the HVAC system of  FIG. 1 , in accordance with embodiments described herein; 
         FIG. 3  is a perspective view of a residential HVAC system, in accordance with embodiments described herein; 
         FIG. 4  is a perspective view of an embodiment of a room side face of an air grille assembly that may be positioned over an opening of an air duct of the HVAC system of  FIGS. 1 and 3 , the air grille assembly having a core positioned within a corridor and including a plurality of deviated channels that obstruct visibility of the air duct, in accordance with embodiments described herein; 
         FIG. 5  is a perspective view of the duct side of the air grille assembly of  FIG. 4 , in accordance with embodiments described herein; 
         FIG. 6  is a cross-sectional view of an embodiment of the air grille assembly of  FIG. 4  along line  6 - 6 , whereby the core includes two rows of blades slanted relative to a corridor axis and that form the deviated passageways, in accordance with embodiments described herein; 
         FIG. 7  is a cross-sectional view of an embodiment of the air grille assembly of  FIG. 4 , whereby the core includes one row of blades positioned orthogonal to the corridor axis and two rows of blades slanted relative to the corridor axis to form the deviated channel, the blades in each respective row of the two slanted rows are slanted in opposite directions, in accordance with embodiments described herein; and 
         FIG. 8  is a cross-sectional view of an embodiment of the air grille assembly of  FIG. 4 , whereby the core includes one row of blades positioned orthogonal to the corridor axis and two rows of blades slanted relative to the corridor axis to form the deviated passageway, the blades in each respective row of the two slanted rows are slanted in the same direction, in accordance with embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is directed toward grille assemblies and, more particularly, air grille assemblies for use with air ducts of heating, ventilation, and air conditioning (HVAC) systems. For example, air grille assemblies of the present disclosure conceal an air duct or open plenum space by completely or partially obstructing a line of sight through the air grille assembly from a room side to a duct side/plenum side of the air grille assembly. Additionally, the air grille assemblies disclosed herein may include a filter utilized to remove air and airborne particulates from a room and return air to an HVAC unit of the HVAC system via the air return duct. The disclosed air grille assemblies include a core having stacked rows of blades that are arranged in a manner that forms a deviated channel, or V-shaped channel, from a room side inlet to a duct side outlet of the air grille assembly. The deviated channel obstructs a line of sight of an observer looking into the air grille assembly from at any location within the room. As such, the disclosed air grille assembly improves the appearance and aesthetics of a room with a return air grille. It should be noted that while the discussion of present embodiments is generally provided in the context of air grille assemblies for air return ducts, the disclosed air grille assemblies can also be used with other features, such as air supply ducts. Indeed, grille assemblies in accordance with present embodiments may be used with various ducts, which may include different types of channels and flow paths. 
     Turning now to the drawings,  FIG. 1  illustrates a heating, ventilation, and air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units and air grille assemblies in accordance with present embodiments. In the illustrated embodiment, a building  10  is air conditioned by a system that includes an HVAC unit  12 . The building  10  may be a commercial structure or a residential structure. As shown, the HVAC unit  12  is disposed on the roof of the building  10 ; however, the HVAC unit  12  may be located in other equipment rooms or areas adjacent the building  10 . The HVAC unit  12  may be a single package unit containing other equipment, such as a blower, integrated air handler, and/or auxiliary heating unit. In other embodiments, the HVAC unit  12  may be part of a split HVAC system, such as the system shown in  FIG. 3 , which includes an outdoor HVAC unit  58  and an indoor HVAC unit  56 . 
     The HVAC unit  12  is an air cooled device that implements a refrigeration cycle to provide conditioned air to the building  10 . Specifically, the HVAC unit  12  may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow is supplied to the building. In the illustrated embodiment, the HVAC unit  12  is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow from the building  10 . After the HVAC unit  12  conditions the air, the air is supplied to the building  10  via ductwork  14  extending throughout the building  10  from the HVAC unit  12 . For example, the ductwork  14  may extend to various individual floors or other sections of the building  10 . In certain embodiments, the HVAC unit  12  may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other embodiments, the HVAC unit  12  may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream. 
     A control device  16 , one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device  16  also may be used to control the flow of air through the ductwork  14 . For example, the control device  16  may be used to regulate operation of one or more components of the HVAC unit  12  or other components, such as dampers and fans, within the building  10  that may control flow of air through and/or from the ductwork  14 . In some embodiments, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the supply air, return air, and so forth. Moreover, the control device  16  may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building  10 . 
       FIG. 2  is a perspective view of an embodiment of the HVAC unit  12 . In the illustrated embodiment, the HVAC unit  12  is a single package unit that may include one or more independent refrigeration circuits and components that are tested, charged, wired, piped, and ready for installation. The HVAC unit  12  may provide a variety of heating and/or cooling functions, such as cooling only, heating only, cooling with electric heat, cooling with dehumidification, cooling with gas heat, or cooling with a heat pump. As described above, the HVAC unit  12  may directly cool and/or heat an air stream provided to the building  10  to condition a space in the building  10 . 
     As shown in the illustrated embodiment of  FIG. 2 , a cabinet  24  encloses the HVAC unit  12  and provides structural support and protection to the internal components from environmental and other contaminants. In some embodiments, the cabinet  24  may be constructed of galvanized steel and insulated with aluminum foil faced insulation. Rails  26  may be joined to the bottom perimeter of the cabinet  24  and provide a foundation for the HVAC unit  12 . In certain embodiments, the rails  26  may provide access for a forklift and/or overhead rigging to facilitate installation and/or removal of the HVAC unit  12 . In some embodiments, the rails  26  may fit into “curbs” on the roof to enable the HVAC unit  12  to provide air to the ductwork  14  from the bottom of the HVAC unit  12  while blocking elements such as rain from leaking into the building  10 . 
     The HVAC unit  12  includes heat exchangers  28  and  30  in fluid communication with one or more refrigeration circuits. Tubes within the heat exchangers  28  and  30  may circulate refrigerant through the heat exchangers  28  and  30 . For example, the refrigerant may be R- 410 A. The tubes may be of various types, such as multichannel and/or microchannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers  28  and  30  may implement a thermal cycle in which the refrigerant undergoes phase changes and/or temperature changes as it flows through the heat exchangers  28  and  30  to produce heated and/or cooled air. For example, the heat exchanger  28  may function as a condenser where heat is released from the refrigerant to ambient air, and the heat exchanger  30  may function as an evaporator where the refrigerant absorbs heat to cool an air stream. In other embodiments, the HVAC unit  12  may operate in a heat pump mode where the roles of the heat exchangers  28  and  30  may be reversed. That is, the heat exchanger  28  may function as an evaporator and the heat exchanger  30  may function as a condenser. In further embodiments, the HVAC unit  12  may include a furnace for heating the air stream that is supplied to the building  10 . While the illustrated embodiment of  FIG. 2  shows the HVAC unit  12  having two of the heat exchangers  28  and  30 , in other embodiments, the HVAC unit  12  may include one heat exchanger or more than two heat exchangers. 
     The heat exchanger  30  is located within a compartment  31  that separates the heat exchanger  30  from the heat exchanger  28 . Fans  32  draw air from the environment through the heat exchanger  28 . Air may be heated and/or cooled as the air flows through the heat exchanger  28  before being released back to the environment surrounding the rooftop unit  12 . A blower assembly  34 , powered by a motor  36 , draws air through the heat exchanger  30  to heat or cool the air. The heated or cooled air may be directed to the building  10  by the ductwork  14 , which may be connected to the HVAC unit  12 . Before flowing through the heat exchanger  30 , the conditioned air flows through one or more filters  38  that may remove particulates and contaminants from the air. In certain embodiments, the filters  38  may be disposed on the air intake side of the heat exchanger  30  to prevent contaminants from contacting the heat exchanger  30 . 
     The HVAC unit  12  also may include other equipment for implementing the thermal cycle. Compressors  42  increase the pressure and temperature of the refrigerant before the refrigerant enters the heat exchanger  28 . The compressors  42  may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors  42  may include a pair of hermetic direct drive compressors arranged in a dual stage configuration  44 . However, in other embodiments, any number of the compressors  42  may be provided to achieve various stages of heating and/or cooling. As may be appreciated, additional equipment and devices may be included in the HVAC unit  12 , such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things. 
     The HVAC unit  12  may receive power through a terminal block  46 . For example, a high voltage power source may be connected to the terminal block  46  to power the equipment. The operation of the HVAC unit  12  may be governed or regulated by a control board  48 . The control board  48  may include control circuitry connected to a thermostat, sensors, and alarms. One or more of these components may be referred to herein separately or collectively as the control device  16 . The control circuitry may be configured to control operation of the equipment, provide alarms, and monitor safety switches. Wiring  49  may connect the control board  48  and the terminal block  46  to the equipment of the HVAC unit  12 . 
       FIG. 3  illustrates a residential heating and cooling system  50 , also in accordance with present techniques. The residential heating and cooling system  50  may provide heated and cooled air to a residential structure, as well as provide outside air for ventilation and provide improved indoor air quality (IAQ) through devices such as ultraviolet lights and air filters. In the illustrated embodiment, the residential heating and cooling system  50  is a split HVAC system. In general, a residence  52  conditioned by a split HVAC system may include refrigerant conduits  54  that operatively couple the indoor unit  56  to the outdoor unit  58 . The indoor unit  56  may be positioned in a utility room, an attic, a basement, and so forth. The outdoor unit  58  is typically situated adjacent to a side of residence  52  and is covered by a shroud to protect the system components and to prevent leaves and other debris or contaminants from entering the unit. The refrigerant conduits  54  transfer refrigerant between the indoor unit  56  and the outdoor unit  58 , typically transferring primarily liquid refrigerant in one direction and primarily vaporized refrigerant in an opposite direction. 
     When the system shown in  FIG. 3  is operating as an air conditioner, a heat exchanger  60  in the outdoor unit  58  serves as a condenser for re-condensing vaporized refrigerant flowing from the indoor unit  56  to the outdoor unit  58  via one of the refrigerant conduits  54 . In these applications, a heat exchanger  62  of the indoor unit functions as an evaporator. Specifically, the heat exchanger  62  receives liquid refrigerant, which may be expanded by an expansion device, and evaporates the refrigerant before returning it to the outdoor unit  58 . 
     The outdoor unit  58  draws environmental air through the heat exchanger  60  using a fan  64  and expels the air above the outdoor unit  58 . When operating as an air conditioner, the air is heated by the heat exchanger  60  within the outdoor unit  58  and exits the unit at a temperature higher than it entered. The indoor unit  56  includes a blower or fan  66  that directs air through or across the indoor heat exchanger  62 , where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork  68  that directs the air to the residence  52 . The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence  52  is higher than the set point on the thermostat, or the set point plus a small amount, the residential heating and cooling system  50  may become operative to refrigerate additional air for circulation through the residence  52 . When the temperature reaches the set point, or the set point minus a small amount, the residential heating and cooling system  50  may stop the refrigeration cycle temporarily. 
     The residential heating and cooling system  50  may also operate as a heat pump. When operating as a heat pump, the roles of heat exchangers  60  and  62  are reversed. That is, the heat exchanger  60  of the outdoor unit  58  will serve as an evaporator to evaporate refrigerant and thereby cool air entering the outdoor unit  58  as the air passes over the heat exchanger  60 . The indoor heat exchanger  62  will receive a stream of air blown over it and will heat the air by condensing the refrigerant. 
     In some embodiments, the indoor unit  56  may include a furnace system  70 . For example, the indoor unit  56  may include the furnace system  70  when the residential heating and cooling system  50  is not configured to operate as a heat pump. The furnace system  70  may include a burner assembly and heat exchanger, among other components, inside the indoor unit  56 . Fuel is provided to the burner assembly of the furnace  70  where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger  62 , such that air directed by the blower  66  passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system  70  to the ductwork  68  for heating the residence  52 . 
       FIGS. 4 and 5  illustrate an embodiment of an air grille assembly  80  that can be positioned over an open end of a duct, such as an air return duct, or a plenum upstream of the duct associated with any of the systems described above.  FIG. 4  illustrates a room side end face  82  of the air grille assembly  80 , and  FIG. 5  illustrates a duct/plenum side end face  84  of the air grille assembly  80 . In one embodiment, the air grille assembly  80  operates to return air to the HVAC unit  12  via the air return duct of the HVAC system. Additionally, the air grille assembly  80  conceals the air return duct, which improve the aesthetics of the room. 
     The air grille assembly  80  includes a housing  86  having a flange  90  on the room side end face  82  and a corridor  92  extending away from the flange  90  toward the duct/plenum side end face  84 . The corridor  92  may be a single wall or an assembly of walls that forms a channel  94  that allows airflow therethrough. For example, air from a room may flow into an air return duct or plenum of the HVAC system via the channel  94 . The channel  94  defines a room side opening  96  and a duct side opening  97 . The channel  94  is sized to fit within an open end of a duct, such as an air return duct, of the HVAC system. The flange  90  extends a distance  99  away from the corridor  92  to facilitate coupling of the air grille assembly  80  to a wall, ceiling, or floor of a room. The flange  90  extends a distance  99  away from the corridor  92  to facilitate installation of the air grille assembly  80  into a T-Bar lay in ceiling grid system. For example, once positioned over the open end of an air return duct, the air grille assembly  80  may be secured onto a desired surface by inserting a coupling member into a receptacle  101  of the flange  90 . By way of non-limiting example, the coupling member may include a nail, screw, bolt, or any other suitable coupling member that can be used to secure the air grille assembly  80  to the desired surface. In certain embodiments, the air grille assembly  80  may be installed in a ceiling T-Bar grid system with no return air ductwork. 
     In the illustrated embodiment, a core  98  is nested within the channel  94  of the corridor  92  such that the core is generally adjacent or forms part of the room side end face  82 . The room side opening  96  may have a dimension  100  that is smaller than a dimension  102  of the duct side opening  97 . For example, a perimeter or length of the room side opening  96  may be incrementally smaller than a respective perimeter or length of the duct side opening  97 . The core  98  may be inserted into the corridor  92  through the duct side opening  97  and sized to fit within the channel  94 . The dimensions of the core  98  are larger than the dimension  100  of the room side opening  96  such that the core  98  is unable to fit through the room side opening  96 . The smaller dimension  100  of the room side opening  96  creates an abutment surface in the channel  94  that supports the core  98  within the housing  86 . 
     The core  98  may be secured within the channel  94  via fasteners  104  disposed on the corridor  92  of the housing  86 . In certain embodiments, the fasteners  104  include a deformable tab or cantilever that may be moved from a first position that is parallel to a corresponding feature of the corridor  92  to a second position that is orthogonal to a corresponding feature of the corridor  92 . In the second position, the deformable tab abuts against a duct side end of the core  98  to secure the core  98  within the channel  94 . In other embodiments, the fasteners  104  may include resilient tabs that secure the core  98  in the channel  94  via a snap-fit mechanism. In certain embodiments, the air grille assembly  80  may include a filter adjacent to the core  98  on the duct side end of the core  98 . The filter may capture additional airborne particulates that may have flowed into the air grille assembly  80 . Additionally, the filter may occlude any portion of the air duct that may remain visible through the air grille assembly  80 . 
     The core  98  includes features that may conceal the duct side of the air grille assembly  80  from an observer on the room side. For example, the core  98  includes a plurality of blades  106 ,  107 . The blades  106 ,  107  form a grid pattern that divides the channel  94  into a plurality of deviated channels  108 . That is, the blades  106 ,  107  are arranged in a cross-wise configuration. The deviated channels  108  direct airflow through the air grille assembly  80  to a desired location, such as to the air return duct of the HVAC system. As discussed in further detail below, the deviated channels  108  completely or partially obstruct visibility through the air grille assembly (such as into the air return duct) when an observer is looking into the air grille assembly  80  from any location within the room. For example, a configuration of the deviated channels  108  may result in a visibility through the air grille assembly  80  that is between 0% and approximately 20%. In certain embodiments, the core  98  includes a filer frame having a filter that facilitates removal of airborne particulates in air passing therethrough and conceals the dust side of the air grille assembly  80  from an observer on the room side. 
       FIG. 6  is a cross-sectional view of an embodiment of the air grille assembly  80  in which the blades  106  are oriented at a non-perpendicular angle  112  relative to a corridor axis  114  of the core  98 , and the blades  107  are oriented orthogonal to the corridor axis  114 . It should be noted that the corridor axis  114  is generally transverse, or orthogonal, to a flow path of air through the corridor  92 , as it would be without the core  98  disposed therein. The blades  106  are slanted and the blades  107  are at an angle of approximately 90 degrees relative to the corridor axis  114  when considered from a common perspective. The blades  107  are spaced apart (evenly in the illustrated embodiment) along the dimension  100  and run orthogonal to the blades  106  along their length, thereby forming the grid pattern and splitting the channel  94  into the deviated channels  108 . It should be noted that the blades  107  are now shown in the cross-sectional view of  FIG. 6  but form border walls of at least portions of the deviated channels  108  in certain embodiments. 
     The slanted orientation of the blades  106  obstruct a line of sight  118  through the air grille assembly  80  from the room side face  82  to the duct side face  84 , thereby concealing the associated duct from observation from the room. For example, the core  98  includes a first row  102   a  having the plurality of blades  106   a  extending along a length  122  of the channel  94  and slanted in a first direction  124  such that each blade  106   a  is oriented at the non-perpendicular angle  112   a  relative to the corridor axis  114 . A second row  102   b  having the plurality of blades  106   b  extending along the length  122  is positioned above the first row  120   a  such that each blade  106   b  in the second row  102   b  is aligned with a respective blade  106   a  in the first row  102   a . The blades  106   b  in the second row  102   b  are slanted in a second direction  128  that is substantially opposite the first direction  124 . As such, similar to the blades  106   a , each blade  106   b  is oriented at the non-perpendicular angle  112   b . By way of non-limiting example, the non-perpendicular angle  112  is between approximately 35 degrees and 50 degrees. In certain embodiments, the non-perpendicular angle  112   a ,  112   b  is the same. In other embodiments, the non-perpendicular angle  112   a  is different from the non-perpendicular angle  112   b . For example, the non-perpendicular angle  112   a  may be 45 degrees and the non-perpendicular angle  112   b  may be 40 degrees. 
     The opposing slanted orientation between the blades  106   a ,  106   b  in each respective row  102   a ,  102   b  creates the deviated channel  108  and partially or completely obstructs the line of sight  118  into the duct through the air grille assembly  80 . For example, in the illustrated embodiment, an end  130   b  of each blade  106   b  in the second row  102   b  is aligned with the end  130   a  of an adjacent blade  106   a  in the first row  102   a . As such, each blade  106   b  in the second row  102   b  extends over an inlet  132  of the deviated channel  108  in a manner that obstructs a view of the air duct through an outlet  134  of the deviated channel  108 . However, in other embodiments, the ends  130   a ,  130   b  of each respective blade  106   a ,  106   b  are not aligned. For example, in certain embodiments, the blades  106   b  may be slanted such that the non-perpendicular angle  112   b  is less than 45 degrees. Therefore, the end  130   b  may extend past the end  130   a  of a respective adjacent blade  106   a . In one embodiment, the end  130   b  of the blade  106   b  is aligned with an end  140  of an adjacent blade  106   a  in the first row  102   a.    
     The core  98  may include any number of rows of the blades  106 . Each row  102   a ,  102   b  may be a separate structure. For example, the core  98  may include core units that make up a single row  102   a ,  102   b  of the blades  106   a ,  106   b . The core units are separate pieces that may be stacked one on top of another to form the deviated channel  108 . In certain embodiments, the core units may be welded together to form a single structure. Any number of core units may be stacked within the housing  86  of the air grille assembly  80 . For example,  FIGS. 7 and 8  illustrate an air grille assembly  150  having a core  152  that includes three rows  154 , or core units, of the blades  106 . The core unit also includes the blades  107  arranged in a cross-wise configuration relative to the blades  106 . In the illustrated embodiments, the blades  106   a  in the first row  154   a  are positioned orthogonal (e.g., at a 90 degree angle relative to the corridor axis  114 ). However, the blades  106  in the subsequent rows  154   b ,  154   c  are slanted, thereby creating the deviated channel  108  and obstructing the line of sight  118  through the air grille assembly  150  and into the air duct of the HVAC system. 
     In certain embodiments, the blades  106   b ,  106   c  in the respective rows  154   b ,  154   c  are slanted in opposite directions. For example, as shown in  FIG. 7 , the blades  106   b  in the second row  154   b  are slanted in the direction  128  and the blades  106   c  in the third row  154   c  are slanted in the substantially opposite direction  124 . However, in other embodiments, the blades  106   b ,  106   c  in each respective row  154   b ,  154   c  are slanted in the same direction  124 ,  128 , as shown in  FIG. 8 . The blades  106   b ,  106   c  may be slanted such that the non-perpendicular angle  112   b ,  112   c  relative to the corridor axis  114  is between approximately 35 degrees and 50 degrees. The non-perpendicular angle  112   b ,  112   c  may be the same or different in the rows  154   b ,  154   c . In certain embodiments, each blade  106   c  is slanted such that the respective end  130   c  is aligned with the end  130   a  of a respective blade  106   a  in the first row  154   a  or the end  130   b  of an adjacent blade  106   b  in the second row  154   b . In this way, each blade  106   c  in the third row  154   c  partially or completely obstructs the line of sight  118  from the inlet  132  to the outlet  134 . Accordingly, for example, when the air grille assembly  80  is utilized as an access port for an air duct of an HVAC system, the air duct cannot be viewed via the air grille assembly  80  by a person at any location within the room. 
     As discussed above, one or more of the disclosed embodiments may provide one or more technical effects useful in HVAC systems associated with the use air grille assemblies. For example, the disclosed embodiments of the present approach may facilitate concealing the air duct or air plenum of the HVAC systems. By specific example, the air grille assembly may include a core having rows of blades stacked on top of one another where the blades in each row are slanted to form a deviated channel that extends from a room side face to a duct/plenum side face of the air grille assembly. The blades in the row adjacent to the duct/plenum side face of the air grille assembly block a line of sight from the inlet to the outlet of the deviated channel. As such, the associated duct/plenum is not visible when looking into the air grille assembly from any location within the room. It should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems. 
     While only certain features and embodiments of the invention have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the invention, or those unrelated to enabling the claimed invention). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.