Patent Publication Number: US-11655997-B2

Title: Damper blade assembly for HVAC system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 62/951,371, entitled “DAMPER BLADE ASSEMBLY FOR HVAC SYSTEM,” filed Dec. 20, 2019, which is herein incorporated by reference in its entirety for all purposes. 
    
    
     BACKGROUND 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     HVAC systems are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. The HVAC system may regulate such environmental properties through control of an air flow delivered to the environment by a blower or a fan. Indeed, the blower may be configured to direct air along a flow path of the HVAC system and across a heat exchanger positioned within the flow path to facilitate exchange of thermal energy between the air and a refrigerant flowing through tubes of the heat exchanger. As such, the blower may direct conditioned air discharging from the heat exchanger to rooms or spaces within a building or other suitable structure serviced by the HVAC system. 
     The HVAC system generally includes various damper assemblies that are operable to regulate air flow along the flow path and/or throughout other sections of the HVAC system. For example, the damper assembly generally includes a plurality of damper blades or louvers that are configured to transition between open positions, closed positions, or various intermediate positions to enable or restrict air flow across the damper assembly and along the flow path. As such, the damper blades may facilitate regulating supply of conditioned air to and extraction of return air from the building. The damper blades are typically constructed from sheet metal or from another metallic material. Unfortunately, metallic damper blades may be difficult to manufacture and assemble, therefore increasing overall manufacturing costs of the HVAC system. 
     SUMMARY 
     The present disclosure relates to a heating, ventilation, and/or air conditioning (HVAC) system that includes a damper assembly configured to regulate airflow and having a frame. The HVAC system includes a first damper blade piece having a first airfoil surface and a second damper blade piece having a second airfoil surface. The first damper blade piece and the second damper blade piece are configured to couple with the frame, and are configured to interlock with one another to form a damper blade having an airfoil shape. 
     The present disclosure also relates to a damper assembly for a heating, ventilation, and/or air conditioning (HVAC) system. The damper assembly includes a frame and a damper blade pivotably coupled to the frame. The damper blade includes a first damper blade piece having a first interlocking feature and a second damper blade piece having a second interlocking feature. The first interlocking feature is engageable with the second interlocking feature to interlock the first damper blade piece and the second damper blade piece to form the damper blade. 
     The present disclosure also relates to a damper blade for a heating, ventilation, and/or air conditioning (HVAC) system. The damper blade includes a first damper blade piece having a first interlocking portion and a second damper blade piece having a second interlocking portion. The second interlocking portion is engageable with the first interlocking portion to interlock the first damper blade piece with the second damper blade piece to form a body of the damper blade having an airfoil shape. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an embodiment of a building that may utilize a heating, ventilation, and/or air conditioning (HVAC) system in a commercial setting, in accordance with an aspect of the present disclosure; 
         FIG.  2    is a perspective view of an embodiment of a packaged HVAC unit, in accordance with an aspect of the present disclosure; 
         FIG.  3    is a perspective view of an embodiment of a split, residential HVAC system, in accordance with an aspect of the present disclosure; 
         FIG.  4    is a schematic diagram of an embodiment of a vapor compression system that may be used in an HVAC system, in accordance with an aspect of the present disclosure; 
         FIG.  5    is a perspective view of an embodiment of an HVAC unit that includes a damper assembly having polymeric damper blades, in accordance with an aspect of the present disclosure; 
         FIG.  6    is a perspective view of an embodiment of a damper assembly having polymeric damper blades, in accordance with an aspect of the present disclosure; 
         FIG.  7    is an exploded perspective view of an embodiment of a polymeric damper blade, in accordance with an aspect of the present disclosure; 
         FIG.  8    is a side view of an embodiment of a polymeric damper blade, in accordance with an aspect of the present disclosure; 
         FIG.  9    is a cross-sectional perspective view of an embodiment of a damper assembly having polymeric damper blades, in accordance with an aspect of the present disclosure; 
         FIG.  10    is a cross-sectional side view of an embodiment of a damper assembly having polymeric damper blades, in accordance with an aspect of the present disclosure; 
         FIG.  11    is an expanded cross-sectional side view, taken within line  11 - 11  of  FIG.  10   , of an embodiment of finger gaskets of polymeric damper blades, in accordance with an aspect of the present disclosure; 
         FIG.  12    is an expanded cross-sectional side view, taken within line  12 - 12  of  FIG.  10   , of an embodiment of a finger gasket of a polymeric damper blade, in accordance with an aspect of the present disclosure; and 
         FIG.  13    is a schematic of an embodiment of an extrusion system for manufacturing polymeric damper blades, in accordance with an aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the present disclosure will be described below. These described embodiments are only examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that 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. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. 
     A heating, ventilation, and/or air conditioning (HVAC) system may be used to thermally regulate a space within a building, home, or other suitable structure. The HVAC system generally includes a vapor compression system that transfers thermal energy between a heat transfer fluid, such as a refrigerant, and a fluid to be conditioned, such as air. The vapor compression system typically includes a condenser and an evaporator that are fluidly coupled to one another via conduits to form a refrigerant circuit. A compressor of the refrigerant circuit may be used to circulate the refrigerant through the conduits and enable the transfer of thermal energy between the condenser and the evaporator. 
     As briefly discussed above, the HVAC system generally includes a blower or a fan that is configured to direct an air flow along a flow path of the HVAC system and across a heat exchanger, such as the evaporator, positioned within the flow path. As such, the blower may facilitate heat exchange between the air flow and the refrigerant circulating through the evaporator. A damper assembly is typically positioned within the flow path and is configured to regulate a flow rate and/or a pressure drop of the air flow along the flow path. For example, the damper assembly generally includes a plurality of damper blades that are pivotably coupled to a frame or to another support structure of the damper assembly. As such, the damper blades may pivot between respective closed positions and various open positions to substantially block or enable, respectively, air flow along the flow path of the HVAC system. Indeed, the damper blades may be used to increase or decrease an effective cross-sectional area of a portion of the flow path through which air may flow in order to regulate air flow along the flow path. 
     In traditional systems, each of the damper blades is typically constructed from metallic blade pieces that are assembled to form the respective damper blade. Unfortunately, manufacturing metallic damper blades may be relatively costly, which increases overall manufacturing costs of the damper assembly and of the HVAC system. Moreover, conventional metallic damper blades may ineffectively engage with one another when the metallic damper blades are transitioned to respective closed positions in the damper assembly. As a result, even when the damper assembly is in a closed configuration, air may leak between the individual damper blades and across the damper assembly. Indeed, conventional damper assemblies may be ill-equipped to block substantially all air flow along the flow path of the HVAC system. 
     It is now recognized that constructing damper blades from one or more polymeric materials may facilitate manufacturing of the damper blades and may therefore reduce manufacturing costs associated with producing the damper blades. In particular, it is now recognized that manufacturing the damper blades via an extrusion process may enable manufacturing of the damper blades without involving arduous metal fabrication techniques that are generally implemented in the manufacture of typical damper blades. Moreover, it is now recognized that constructing damper blades from polymeric materials enables formation of integral blade sealing features with the damper blades that facilitate forming fluid seals and blocking air flow between adjacent damper blades when the damper blades are in closed positions within the damper assembly. 
     Accordingly, embodiments of the present disclosure are directed to a polymeric damper blade that is configured to reduce or substantially eliminate the shortcomings of conventional damper blades set forth above. For example, in some embodiments, the polymeric damper blade includes a first damper blade piece and a second damper blade piece that are formed from a polymeric material via an extrusion process. In particular, the first and second damper blades pieces may include self-similar components that are detached from a common stock of extruded, polymeric material. As discussed in detail below, the first and second damper blades pieces are configured to interlock with one another to collectively form a body of a particular damper blade. As such, the polymeric damper blades disclosed herein may be manufactured more easily than conventional damper blades that are typically assembled via crimping or metallurgical processes, such as welding or brazing. In some embodiments, each of the polymeric damper blades may include one or more integrated blade sealing features, also referred to herein as finger gaskets, which extend from respective edges of the damper blades. When the polymeric damper blades are in an installed configuration in a damper assembly, the finger gaskets of adjacent damper blades are configured to engage with one another when the damper blades are transitioned to closed positions to facilitate formation of a fluid seal between the adjacent damper blades in the damper assembly. As such, damper assemblies equipped with polymeric damper blades manufactured in accordance with the techniques discussed herein may more effectively block air flow along a flow path than damper assemblies having typical damper blades. These and other features will be described below with reference to the drawings. 
     Turning now to the drawings,  FIG.  1    illustrates an embodiment of a heating, ventilation, and/or air conditioning (HVAC) system for environmental management that may employ one or more HVAC units. As used herein, an HVAC system includes any number of components configured to enable regulation of parameters related to climate characteristics, such as temperature, humidity, air flow, pressure, air quality, and so forth. For example, an “HVAC system” as used herein is defined as conventionally understood and as further described herein. Components or parts of an “HVAC system” may include, but are not limited to, all, some of, or individual parts such as a heat exchanger, a heater, an air flow control device, such as a fan, a sensor configured to detect a climate characteristic or operating parameter, a filter, a control device configured to regulate operation of an HVAC system component, a component configured to enable regulation of climate characteristics, or a combination thereof. An “HVAC system” is a system configured to provide such functions as heating, cooling, ventilation, dehumidification, pressurization, refrigeration, filtration, or any combination thereof. The embodiments described herein may be utilized in a variety of applications to control climate characteristics, such as residential, commercial, industrial, transportation, or other applications where climate control is desired. 
     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, such as R- 410 A, through the heat exchangers  28  and  30 . The tubes may be of various types, such as multichannel 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 HVAC unit  12 . A blower  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  56  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 a 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 a 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 outdoor 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 system  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 . 
       FIG.  4    is an embodiment of a vapor compression system  72  that can be used in any of the systems described above. The vapor compression system  72  may circulate a refrigerant through a circuit starting with a compressor  74 . The circuit may also include a condenser  76 , an expansion valve(s) or device(s)  78 , and an evaporator  80 . The vapor compression system  72  may further include a control panel  82  that has an analog to digital (A/D) converter  84 , a microprocessor  86 , a non-volatile memory  88 , and/or an interface board  90 . The control panel  82  and its components may function to regulate operation of the vapor compression system  72  based on feedback from an operator, from sensors of the vapor compression system  72  that detect operating conditions, and so forth. 
     In some embodiments, the vapor compression system  72  may use one or more of a variable speed drive (VSDs)  92 , a motor  94 , the compressor  74 , the condenser  76 , the expansion valve or device  78 , and/or the evaporator  80 . The motor  94  may drive the compressor  74  and may be powered by the variable speed drive (VSD)  92 . The VSD  92  receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor  94 . In other embodiments, the motor  94  may be powered directly from an AC or direct current (DC) power source. The motor  94  may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor. 
     The compressor  74  compresses a refrigerant vapor and delivers the vapor to the condenser  76  through a discharge passage. In some embodiments, the compressor  74  may be a centrifugal compressor. The refrigerant vapor delivered by the compressor  74  to the condenser  76  may transfer heat to a fluid passing across the condenser  76 , such as ambient or environmental air  96 . The refrigerant vapor may condense to a refrigerant liquid in the condenser  76  as a result of thermal heat transfer with the environmental air  96 . The liquid refrigerant from the condenser  76  may flow through the expansion device  78  to the evaporator  80 . 
     The liquid refrigerant delivered to the evaporator  80  may absorb heat from another air stream, such as a supply air stream  98  provided to the building  10  or the residence  52 . For example, the supply air stream  98  may include ambient or environmental air, return air from a building, or a combination of the two. The liquid refrigerant in the evaporator  80  may undergo a phase change from the liquid refrigerant to a refrigerant vapor. In this manner, the evaporator  80  may reduce the temperature of the supply air stream  98  via thermal heat transfer with the refrigerant. Thereafter, the vapor refrigerant exits the evaporator  80  and returns to the compressor  74  by a suction line to complete the cycle. 
     In some embodiments, the vapor compression system  72  may further include a reheat coil in addition to the evaporator  80 . For example, the reheat coil may be positioned downstream of the evaporator relative to the supply air stream  98  and may reheat the supply air stream  98  when the supply air stream  98  is overcooled to remove humidity from the supply air stream  98  before the supply air stream  98  is directed to the building  10  or the residence  52 . 
     It should be appreciated that any of the features described herein may be incorporated with the HVAC unit  12 , the residential heating and cooling system  50 , or other HVAC systems. Additionally, while the features disclosed herein are described in the context of embodiments that directly heat and cool a supply air stream provided to a building or other load, embodiments of the present disclosure may be applicable to other HVAC systems as well. For example, the features described herein may be applied to mechanical cooling systems, free cooling systems, chiller systems, or other heat pump or refrigeration applications. 
     As discussed above, HVAC systems typically include a damper assembly having a plurality of actuatable damper blades that facilitate regulation of air flow along a flow path of the HVAC system. Typical damper blades are generally constructed from metallic blade pieces that are assembled to form the respective damper blades. Manufacturing of metallic damper blades may be costly, and thus, may increase overall manufacturing costs of the HVAC system. Moreover, metallic damper blades may ineffectively block air flow across the damper assembly when the damper assembly is transitioned to or position in a closed configuration. Accordingly, embodiments of the present disclosure are directed toward a polymeric damper blade that may be less costly to manufacture than metallic damper blades and that enhances an air-blocking ability of the damper assembly. 
     For example, to provide context for the following discussion,  FIG.  5    is a perspective view of an embodiment of the HVAC unit  12  that includes a damper assembly  100 . It should be understood that, in the illustrated embodiment of the HVAC unit  12 , a portion of the cabinet  24  is removed to show components positioned within an interior of the HVAC unit  12 , such as the damper assembly  100 . The damper assembly  100  may be positioned within a suitable flow path  101  of the HVAC unit  12 , which may be defined by the cabinet  24 . The damper assembly  100  is configured to regulate air flow characteristics, such as flow rate and/or pressure drop, along the flow path  101 . Indeed, as discussed in detail below, the damper assembly  100  includes a plurality of polymeric damper blades  102  that are configured to selectively transition between respective closed positons  103  and respective open positions  104  to restrict or enable air flow along the flow path  101 . As such, the damper assembly  100  may be used to facilitate regulation of an air flow that may be forced along the flow path  101  via, for example, the blower  34 . 
     It should be understood that embodiments of the damper assembly  100  and the damper blades  102  may also be included in embodiments or components of the split, residential HVAC system  50  shown in  FIG.  3   , a rooftop unit (RTU), or any other suitable HVAC system. Moreover, it should be understood that the embodiments of the damper blades  102  discussed herein are not limited to implementation on the damper assembly  100 , and instead, may be configured for use on any suitable damper, vent register, or other flow control device or flow control mechanism. 
     With the foregoing in mind,  FIG.  6    is a perspective view of an embodiment of the damper assembly  100 . In the illustrated embodiment, each of the damper blades  102  is pivotably coupled to a frame  105  or to a suitable support structure of the damper assembly  100 . Accordingly, the damper blades  102  may pivot about respective axes  106  and relative to the frame  105  to facilitate air flow regulation through a central flow path  108  of the damper assembly  100 , which may include a portion of the flow path  101 . For example, as briefly discussed above, the damper blades  102  are selectively pivotable between the respective closed positions  103 , in which the damper blades  102  substantially block air flow along the central flow path  108 , and the respective open positions  104  or partially open positions, in which the damper blades  102  enable air flow along the central flow path  108 . As discussed below, in some embodiments, one or more actuators  114  may be coupled to the damper blades  102  via suitable linkages or gearing mechanisms and configured to transition the damper blades  102  between the respective closed positions  103  and the respective open positions  104  or the partially open positions. 
       FIG.  7    is an exploded perspective view of an embodiment one of the damper blades  102 , referred to herein as a damper blade  120 . As shown in the illustrated embodiment, the damper blade  120  includes a first damper blade piece  122  and a second damper blade piece  124  that may each include a generally curved profile. As discussed below, the first and second damper blade pieces  122 ,  124  are configured to interlock with one another to form a body  126 , as shown in  FIG.  8   , of the damper blade  120 , which may have an airfoil shape. 
     The damper blade  120  may include a first pivoting bracket  130  and a second pivoting bracket  132  that are configured to couple to and be positioned between the first and second damper blade pieces  122 ,  124  when the first and second damper blade pieces  122 ,  124  are interlocked to form the body  126 . The first pivoting bracket  130  and the second pivoting bracket  132  may each include a respective pivot rod  134  that is configured to facilitate pivotable coupling of the damper blade  120  to the frame  105 . For example, the pivot rods  134  may be configured to engage with respective bearings or bushings of the frame  105  to enable the damper blade  120  to pivot about a corresponding one of the axes  106 , relative the frame  105 , between corresponding closed and open positions  103 ,  104 . In some embodiments, one or both of the pivot rods  134  may be coupled to the one or more actuators  114  via a linkage assembly, a gearing assembly, or another suitable mechanism. Accordingly, the one or more actuators  114  may be used to selectively pivot the damper blade  120  about the corresponding axis  106 . 
     In some embodiments, the damper blade  120  includes one or more C-channel braces  138  that, similar to the first and second damper blade pieces  122 ,  124 , are configured to couple to and be positioned between the first and second damper blade pieces  122 ,  124  when the first and second damper blade pieces  122 ,  124  are interlocked to form the body  126 . In certain embodiments, the C-channel braces  138  may be formed from metal or from a rigid polymer and, as such, may enhance a structural rigidity of the body  126  when coupled to the first and second damper blade pieces  122 ,  124 . In some embodiments, respective lengths  140  of the C-channel braces  138  may be less than respective lengths  142  of the first and second damper blade pieces  122 ,  124 . Therefore, when coupled to the first and second damper blade pieces  122 ,  124 , the C-channel braces  138  may be interposed between the first and second pivoting brackets  130 ,  132 . Indeed, in some embodiments, respective lengths  144  of the first and second pivoting brackets  130 ,  132 , combined with the length  140  of one of the C-channel braces  138 , may define a cumulative length that is substantially equal to or less than the length  142  of the first or second damper blade pieces  122 ,  124 . 
       FIG.  8    is a side view of an embodiment of the damper blade  120 . As shown in the illustrated embodiment, the first damper blade piece  122  includes a first airfoil surface  150  and a first inner surface  152  that is opposite to the first airfoil surface  150 . As such, the first airfoil surface  150  and the first inner surface  152  may define opposing surfaces of the first damper blade piece  122  that extend between a first end portion  154  of the first damper blade piece  122  and a second end portion  156  of the first damper blade piece  122 . Similar to the first damper blade piece  122 , the second damper blade piece  124  includes a second airfoil surface  158  and a second inner surface  160  that is opposite to the second airfoil surface  158 . Accordingly, the second airfoil surface  158  and the second inner surface  160  may define opposing surfaces of the second damper blade piece  124  that extend between a first end portion  162  of the second damper blade piece  124  and a second end portion  164  of the second damper blade piece  124 . 
     As briefly discussed above, the first and second damper blade pieces  122 ,  124  may each include interlocking features  166  that are configured to engage with one another to couple or interlock the first and second damper blade pieces  122 ,  124  with one another to form the body  126 . For example, in the illustrated embodiment, the first damper blade piece  122  includes a first protrusion  170  that extends outwardly from a first curved segment  172  of the first damper blade piece  122 , and the second damper blade piece  124  includes a second protrusion  174  that extends outwardly from a second curved segment  176  of the second damper blade piece  124 . As such, the first protrusion  170  may define a portion of the first inner surface  152  of the first damper blade piece  122 , and the second protrusion  174  may define a portion of the second inner surface  160  of the second damper blade piece  124 . For clarity, it should be understood that the first curved segment  172  may include a body portion of the first damper blade piece  122  that extends between the first and second end portions  154 ,  156  of the first damper blade piece  122 , and that the second curved segment  176  may include a body portion of the second damper blade piece  124  that extends between the first and second end portions  162 ,  164  of the second damper blade piece  124 . 
     The first damper blade piece  122  includes a first pair of prongs  178  that extend outwardly from the first curved segment  172  to define a first retention slot  180 , and the second damper blade piece  124  includes a second pair of prongs  182  that extend outwardly from the second curved segment  176  to define a second retention slot  184 . Accordingly, the first pair of prongs  178  and the second pair of prongs  182  may define portions of the first and second inner surfaces  152 ,  160 , respectively. For clarity, it should be understood that the first protrusion  170  and the first retention slot  180  may define the interlocking features  166  of the first damper blade piece  122 , and that the second protrusion  174  and the second retention slot  184  may define the interlocking features  166  of the second damper blade piece  124 . 
     As shown in the illustrated embodiment, the first protrusion  170  is configured to engage with the second retention slot  184 , and the second protrusion  174  is configured to engage with the first retention slot  180 . Particularly, the first and second protrusions  170 ,  174  may be engaged with the second and first retention slots  184 ,  180 , respectively, by translating the first and second damper blade pieces  122 ,  124  in opposing directions relative to one another along the axis  106 . As such, the interlocking features  166  may engage with one another and facilitate interlocking the first and second damper blade pieces  122 ,  124  to form the body  126  of the damper blade  120 . In some embodiments, respective interference fits between the first protrusion  170  and the second retention slot  184 , and between the second protrusion  174  and the first retention slot  180 , may facilitate retaining the first and second damper blade pieces  122 ,  124  in an engaged or interlocked configuration by blocking relative movement between the first and second damper blade pieces  122 ,  124  and/or disengagement of the first and second damper blade pieces  122 ,  124 . 
     It should be appreciated that, in other embodiments, the first and second protrusions  170 ,  174  may be pressed into the second and first retention slots  184 ,  180 , respectively, to facilitate coupling of the first and second damper blade pieces  122 ,  124  via a snap fit. To this end, the first and second protrusions  170 ,  174  and/or the first and second pairs of prongs  178 ,  182  may be formed of a resilient yet flexible material that enables elastic deformation. Moreover, it should be appreciated that, in other embodiments, the interlocking features  166  may include any other suitable shape, geometry, and/or orientation relative to one another. Indeed, the interlocking features  166  may include any suitable features that may be molded into or otherwise formed integrally with the first and second damper blade pieces  122 ,  124  and configured to engage with one another to facilitate interlocking of the first and second damper blade pieces  122 ,  124 . As discussed above, it should be understood that the first and second damper blade pieces  122 ,  124  may be substantially self-similar components, such that the first damper blade piece  122  may include the same features as the second damper blade piece  124  and vice versa. In other words, the first and second damper blade pieces  122 ,  124  may be used interchangeably with one another. Indeed, as shown in the illustrated embodiment, the interlocking features  166  of the first damper blade piece  122  may be substantially self-similar to the interlocking features  166  of the second damper blade piece  124 . 
     In some embodiments, the first damper blade piece  122  includes a first set of retention prongs  190  that extend outwardly from the first curved segment  172  to define first retention grooves  192  of the first damper blade piece  122 . Similar to the first damper blade piece  122 , the second damper blade piece  124  may include a second set of retention prongs  194  that extend outwardly from the second curved segment  176  to define second retention grooves  196  of the second damper blade piece  124 . Accordingly, the first set of retention prongs  190  and the second set of retention prongs  194  may define portions of the first and second inner surfaces  152 ,  160 , respectively. As shown in the illustrated embodiment, corresponding ones of the first and second retention grooves  192 ,  196  are configured to receive one of the C-channel braces  138 . As such, the C-channel braces  138  may enhance a structural rigidity of the body  126  by coupling the first and second damper blade pieces  122 ,  124  to one another. It should be appreciated that an interference fit between the C-channel braces  138  and the corresponding first and second retention grooves  192 ,  196  may facilitate retention of the C-channel braces  138  within the first and second retention grooves  192 ,  196 . Although the illustrated embodiment of the damper blade  120  includes two C-channel braces  138 , in other embodiments, the damper blade  120  may include any suitable quantity of C-channel braces  138 . Moreover, the C-channel braces  138  are not limited to channel-type shapes, and instead, may include any suitable shapes or geometries that facilitate coupling the first damper blade piece  122  to the second damper blade piece  124 . 
     As shown in the illustrated embodiment, the first pivoting bracket  130  may be positioned between the first and second damper blade pieces  122 ,  124  and located within an interior region  198  of the body  126 . In particular, the first pivoting bracket  130  may include a central portion  200  that is configured to be positioned between respective locating ribs  202  formed within the first and second damper blade pieces  122 ,  124 . The central portion  200  may engage with the first and second inner surfaces  152 ,  160  via, for example, an interference fit between the central portion  200  and the first and second damper blade pieces  122 ,  124 . The central portion  200  may include an inner geometry or inner profile that corresponds to or matches with an outer geometry or outer profile of the pivot rod  134  to facilitate torque transfer between the pivot rod  134  and the central portion  200 . In some embodiments, the first pivoting bracket  130  may include opposing legs  204  that extend outwardly from the central portion  200  and are configured to engage with the first inner surface  152 , the second inner surface  160 , or both. In some embodiments, the legs  204  may facilitate transfer of rotational torque from the first pivoting bracket  130  to the first and second damper blade pieces  122 ,  124 , such as when the one or more actuators  114  drive the pivot rods  134  about the axis  106 . It should be understood that the second pivoting bracket  132  may include some of or all of the features of the first pivoting bracket  130  and may be configured to engage with the first and second damper blade pieces  122 ,  124  in a substantially similar manner as that of the first pivoting bracket  130  discussed above. Moreover, as noted above, it should be understood that the C-channel braces  138  may be interposed between the first and second pivoting brackets  130 ,  132 . 
     In some embodiments, one or more flanges  206  may be coupled to the pivot rods  134  of the first pivoting bracket  130  and/or the second pivoting bracket  132  to facilitate coupling the pivots rods  134  to the one or more actuators  114 . For example, in the illustrated embodiment, the flange  206  is coupled to the pivot rod  134  of the second pivoting bracket  132 . The flange  206  may include a mounting aperture  208  that is engageable with a pivoting linkage or mechanism coupled to the one or more actuators  114 . As such, the second pivoting bracket  132  and the pivoting linkage enable the one or more actuators  114  to induce motion of the damper blade  120  about the axis  106 . 
       FIG.  9    is a perspective cross-sectional view of an embodiment of the damper assembly  100 , referred to herein as a damper assembly  210 , which includes a pair of the damper blades  102 , such as a first damper blade  212  and a second damper blade  214 . The first damper blade  212  and the second damper blade  214  may each include the features of the damper blade  120  discussed above. It should be appreciated that other embodiments of the damper assembly  210  may include any suitable quantity of the damper blades  102 . 
     In the illustrated embodiment, the first and second damper blades  212 ,  214  each include finger gaskets  216  or blade sealing features that extend from respective edges  218  of the first and second damper blades  212 ,  214  and extend along respective lengths of the first and second damper blades  212 ,  214 . In particular, the first damper blade  212  includes a first finger gasket  220  that is configured to engage with a second finger gasket  222  of the second damper blade  214  at an interface  224  when the first and second damper blades  212 ,  214  are transition to the closed positions  103 . In this manner, the first and second finger gaskets  220 ,  222  may facilitate formation of a fluid seal between the first damper blade  212  and the second damper blade  214  at the interface  224 . Moreover, as discussed in detail below, the first damper blade  212  includes a third finger gasket  226  that is configured to engage with a first gasket strip  228 , which may be disposed along the frame  105 , when the first damper blade  212  is in the respective closed position  103 . Similarly, the second damper blade  214  includes a fourth finger gasket  230  that is configured to engage with a second gasket strip  232  disposed along the frame  105  when the second damper blade  214  is in the respective closed position  103 . As such, the third finger gasket  226  may facilitate formation of a fluid seal between the first damper blade  212  and the first gasket strip  228  to substantially block air flow between the first gasket strip  228  and the first damper blade  212  when the first damper blade  212  is in the corresponding closed position  103 , and the fourth finger gasket  230  may facilitate formation of a fluid seal between the second damper blade  214  and the second gasket strip  232  to substantially block air flow between the second gasket strip  232  and the second damper blade  214  when the second damper blade  214  is in the corresponding closed position  103 . The first and second gasket strips  228 ,  232  may include sheet metal strips, rubber strips, or another other suitable material strips that are configured to engage with the third and fourth finger gaskets  226 ,  230  and form a fluid seal therewith. 
     To better illustrate the finger gaskets  216  of the first and second damper blades  212 ,  214  and to facilitate the following discussion,  FIG.  10    is a cross-sectional side view of the damper assembly  210 . Additionally,  FIG.  11    is an expanded cross-sectional side view taken within line  11 - 11  of  FIG.  10   , illustrating the engagement between the first finger gasket  220  and the second finger gasket  222  at interface  224 . Further,  FIG.  12    is an expanded side cross-sectional view taken within line  12 - 12  of  FIG.  10   , illustrating the engagement between the third finger gasket  226  and the first gasket strip  228 .  FIGS.  10 ,  11 , and  12    are discussed concurrently below. 
     Each of the finger gaskets  216  include body portions  240  that extend from respective edges  242  of the first and second damper blade pieces  122 ,  124 . Indeed, in some embodiments, the finger gaskets  216  may be formed integrally with the first and second damper blade pieces  122 ,  124  of the first and second damper blades  212 ,  214 . As such, the body portions  240  may form respective portions of the first and second inner surfaces  152 ,  160  and of the first and second airfoil surfaces  150 ,  158  of the first and second damper blades  212 ,  214 . It should be appreciated that, in other embodiments, the finger gaskets  216  may be separate components that may be coupled to the first or second damper blade pieces  122 ,  124  via adhesives or other suitable techniques. 
     In the closed positions  103  of the first and second damper blades  212 ,  214 , the body portions  240  of the first and second finger gaskets  220 ,  222  may overlap with one another along a first region of overlap  250 . Moreover, in the closed positions  103  of the first and second damper blades  212 ,  214 , the third finger gasket  226  may overlap with the first gasket strip  228  along a second region of overlap  252 , and the fourth finger gasket  230  may overlap with the second gasket strip  232  and a third region of overlap. 
     The finger gaskets  216  may each include a finger protrusion  254  that extends outwardly from the body portion  240  and a finger groove  255  formed in the body portion  240 . In some embodiments, when the first and second damper blades  212 ,  214  are in the closed positions  103 , a first finger protrusion  256  of the first finger gasket  220  may extend into and engage or mate with a corresponding first finger groove  258  of the second finger gasket  222 . Additionally, when the first and second damper blades  212 ,  214  are in the closed positions  103 , a second finger protrusion  260  of the second finger gasket  222  may extend into and engage or mate with a corresponding second finger groove  262  of the first finger gasket  220 . The engagement between the first and second finger protrusions  256 ,  260  and the first and second finger grooves  258 ,  262 , respectively, may facilitate formation of a fluid seal between the first damper blade  212  and the second damper blade  214  at the interface  224  when the damper blades  212 ,  214  are transitioned to the closed positions  103 . 
     In some embodiments, the first and second finger gaskets  220 ,  222  may temporarily flex or bend when engaged with one another at the interface  224 , such that a compressive force is applied between the first and second finger gaskets  220 ,  222  when the first and second damper blades  212 ,  214  are in the closed positions  103 . As such, the compressive force between the first and second finger gaskets  220 ,  222  may ensure that the finger protrusions  256 ,  260  remain engaged with the corresponding finger grooves  258 ,  262  to form the fluid seal at the interface  224 . 
     As shown in  FIG.  12   , a third finger protrusion  264  of the third finger gasket  226  is configured to contact and engage with the first gasket strip  228 . Similar to the first and second finger gaskets  220 ,  222  discussed above, the third finger gasket  226  and the first gasket strip  228  may temporarily flex or bend when engaged with one another. As such, a compressive force may be applied between the third finger gasket  226  and the first gasket strip  228  that facilitates formation of a fluid seal between the third finger gasket  226  and the first gasket strip  228 . 
     As discussed above, in certain embodiments, the first damper blade piece  122  may be substantially self-similar to the second damper blade piece  124 . That is, the first damper blade piece  122  may include some of or all of the features of the second damper blade piece  124 , and vice versa. Indeed, in some embodiments, the first damper blade piece  122  and the second damper blade piece  124  may be manufactured from, for example, a common stock of extruded polymer, such as polyvinyl chloride (PVC). 
     For example, to facilitate discussion of an embodiment of an extrusion process that may be used to manufacture the first and second damper blade pieces  122 ,  124 ,  FIG.  13    is a schematic diagram of an extrusion system  270 . As shown in the illustrated embodiment, the extrusion system  270  may include an extruder  272  that is configured to receive a supply of material from a material supply  274 . For example, the material supply  274  may supply the extruder  272  with rolls, sheets, or pellets of a polymeric material or a mixture of polymeric materials. The extruder  272  may be configured to heat the polymeric material to a molten state or to an otherwise ductile state and to force the molten polymeric material through a guide to form a continuous strip of blade stock  276 . The blade stock  276  may include a portion of or all of the features of the first and second damper blade pieces  122 ,  124  discussed above, such as, for example, the interlocking features  166  and the finger gaskets  216 . That is, the guide of the extruder  272  may include a mold having geometries configured to form the features of the first and second damper blade pieces  122 ,  124  discussed herein. 
     In some embodiments, a cutting tool  278  may be used to detach individual sections  280  of the blade stock  276  to form a plurality of damper blade pieces  282 . Each of the damper blade pieces  282  may be used as either the first damper blade piece  122  or the second damper blade piece  124 . Indeed, it should be understood that, because the first damper blade piece  122  and the second damper blade piece  124  are self-similar, any two of the damper blade pieces  282  may be used to assemble the body  126  of the damper blade  120  or corresponding bodies of the first and second damper blades  212 ,  214 . As such, the extrusion system  270  may facilitate rapid and cost effective manufacturing of the damper blades  102 . Moreover, by adjusting a cutting distance by which the cutting tool  278  detaches the sections  280  from the blade stock  276 , various sizes of damper blades  102  may be manufactured using the extrusion system  270 . However, it should be appreciated that, in other embodiments, any other suitable manufacturing technique may be used to manufacture the first and second damper blade pieces  122 ,  124 . As an example, the first and second damper blade pieces  122 ,  124  may be formed via a suitable additive manufacturing process or an injection molding process. 
     As set forth above, embodiments of the present disclosure may provide one or more technical effects useful for constructing damper blades from polymeric material to facilitate manufacturing of the damper blades and to reduce manufacturing costs associated with producing the damper blades. In particular, by manufacturing polymeric damper blades in accordance with the techniques disclosed herein, use of complicated metal fabrication machinery that may be implemented in the manufacture of typical metallic damper blades may be reduced or substantially eliminated. Moreover, embodiments of the damper blades discussed herein include blade sealing features, such as the finger gaskets, that enhance an ability of the damper blades to block airflow across the damper assembly when in respective closed positions. It should be understood that the technical effects and technical problems in the specification are examples and are not limiting. Indeed, 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 have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, such as temperatures and pressures, mounting arrangements, use of materials, colors, orientations, and so forth, 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 disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode, or those unrelated to enablement. 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.