Patent Publication Number: US-2021172646-A1

Title: High velocity wind-driven rain louver

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 62/944,954, entitled “HIGH VELOCITY WIND-DRIVEN RAIN LOUVER,” filed Dec. 6, 2019, which is hereby 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 and 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 noted that these statements are to be read in this light, and not as admissions of prior art. 
     Heating, ventilation, and/or air conditioning (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. An HVAC system may control the environmental properties through control of an air flow delivered to and/or ventilated from a space. For example, the HVAC system may place the air flow in a heat exchange relationship with a refrigerant of a vapor compression circuit. The air flow may be directed through the HVAC system via a louver assembly. The louver assembly may include blades that are implemented to block certain elements, such as debris and precipitation, from flowing through the louver assembly. It is recognized that an improved louver assembly design is desirable to increase blockage of elements while enabling desired air flow through the louver assembly. 
     SUMMARY 
     A summary of certain embodiments disclosed herein is set forth below. It should be noted 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 one embodiment, a louver blade for a louver assembly includes a first section, a second section extending from the first section and including a crest of the louver blade, an extension extending from the second section to form a recess between the extension and the second section, and a protrusion extending from the second section toward the extension and configured to facilitate retention of the particles within the recess. The extension is configured guide particles into the recess in an installed configuration of the louver blade with the louver assembly. 
     In one embodiment, a louver assembly for a heating, ventilation, and air conditioning (HVAC) system includes a louver blade. The louver blade has a first portion, a second portion extending from the first portion and forming a crest with the first portion, a first extension extending from the second portion on a first side of the louver blade to form a first recess between the second portion and the first extension, and a second extension extending from the second portion on a second side of the louver blade, opposite the first side, to form a second recess between the second portion and the second extension. The first extension and the second extension overlap with one another along an axis crosswise to a direction of air flow through the louver assembly. The louver assembly also includes a jamb frame coupled to the louver blade. The jamb frame includes a first channel and a second channel, the first channel is aligned with the first recess relative to the direction of air flow through the louver assembly, and the second channel is aligned with the second recess relative to the direction of air flow through the louver assembly. 
     In one embodiment, a louver blade for a louver assembly includes an upstream section comprising an incline portion, a midstream section having a decline portion extending from the incline portion to form a crest of the louver blade with the incline portion on a first side of the louver blade, and a downstream section extending from the midstream section. The louver assembly also includes an extension of the midstream section, the extension extending in an upstream direction to form a recess between the extension and the midstream section on the first side of the louver blade, and a protrusion of the midstream section, the protrusion extending toward the recess and is configured to retain liquid particles captured within the recess. 
    
    
     
       DRAWINGS 
       Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is a perspective view of an embodiment of a heating, ventilation, and/or air conditioning (HVAC) system for environmental management that may employ one or more HVAC units, in accordance with an aspect of the present disclosure; 
         FIG. 2  is a perspective cutaway view of an embodiment of a louver assembly that may be incorporated in an HVAC system, in accordance with an aspect of the present disclosure; 
         FIG. 3  is an exploded perspective view of an embodiment of a louver assembly that may be incorporated in an HVAC system, in accordance with an aspect of the present disclosure; 
         FIG. 4  is a partial perspective view of an embodiment of a louver blade that may be incorporated in a louver assembly, in accordance with an aspect of the present disclosure; 
         FIG. 5  is an axial view of an embodiment of louver blades that may be incorporated in a louver assembly, in accordance with an aspect of the present disclosure; 
         FIG. 6  is an axial view of an embodiment of a head frame and a louver blade that may be incorporated in a louver assembly, in accordance with an aspect of the present disclosure; 
         FIG. 7  is an axial view of an embodiment of a sill frame and a louver blade that may be incorporated in a louver assembly, in accordance with an aspect of the present disclosure; 
         FIG. 8  is a top view of an embodiment of a jamb frame that may be incorporated in a louver assembly, in accordance with an aspect of the present disclosure; 
         FIG. 9  is an axial view of an embodiment of louver blades that may be incorporated in a louver assembly, in accordance with an aspect of the present disclosure; and 
         FIG. 10  is an axial view of an embodiment of a louver blade that may be incorporated in a louver assembly, in accordance with an aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be noted 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 noted 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 noted 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. 
     The present disclosure is directed to a louver assembly for a heating, ventilation, and/or air conditioning (HVAC) system. The louver assembly may enable air to move into and/or out of the HVAC system or another enclosed space. For instance, the louver assembly may be disposed at an inlet of the HVAC system to enable control of an air flow from an ambient environment into the HVAC system, where the HVAC system may condition the air flow by adding and/or removing heat from the air flow. The louver assembly may additionally or alternatively be disposed at an outlet of the HVAC system to enable control of an air flow directed out of the HVAC system, such as to condition a space serviced by the HVAC system and/or to discharge an exhaust air flow. In further embodiments, the louver assembly may be configured to control an air flow within the HVAC system, such as between different components or portions of the HVAC system. 
     The louver assembly may include a frame (e.g., defined by frame segments) and blades secured to the frame. The frame may be coupled to another component of the HVAC system, such as to an air handler, ductwork, a support structure, and/or a heat exchanger, to enable control of air flow through the HVAC system. The blades may be disposed in the frame and may be arranged to block solid and/or liquid particles, including precipitation, dirt, and/or other debris, from passing through the louver assembly and into the HVAC system or another enclosed space. Indeed, it may be desirable to block solid and/or liquid particles from entering the HVAC system or enclosed space. For instance, the louver assembly may be subject to various standards and/or certifications indicative of an ability of the louver assembly to block solid and/or liquid elements from passing through the louver assembly. As an example, the louver assembly may be subject to criteria of the Air Movement and Control Association International, Inc. (AMCA) 550 standard for wind-driven rain resistance, in which the performance of the louver assembly during simulated rainfall at various wind speeds (e.g., 35 miles per hour, 70 miles per hour, 90 miles per hour, 110 miles per hour) is evaluated. The performance of the louver assembly may be assessed based on an amount or rate of water (e.g., 22 centimeters or 8.8 inches per hour) that passes through the louver assembly during simulated conditions. Certain blades of existing louver assemblies may not adequately block solid and/or liquid particles from passing through the louver assemblies. For example, the solid and/or liquid particles may pass through openings of the louver assembly formed between the blades. In other existing louver assemblies, blades may not enable sufficient air flow through the louver assemblies. For instance, the geometry of the blades may impart an elevated pressure drop that blocks air from flowing through the louver assemblies at a desirable flow rate. In either case, performance of such louver assemblies is undesirable. 
     Thus, it is presently recognized that a louver assembly with blades designed to adequately block solid and/or liquid particles from flowing through the louver assembly while enabling air to flow through the louver assembly at a desirable flow rate may improve performance of the louver assembly and of an HVAC system incorporating the louver assembly. Accordingly, embodiments of the present disclosure are directed to a louver assembly having louver blades that include extensions configured to function as barriers that block solid and/or liquid particles from flowing across the louver blades. Further, each louver blade may include recesses that retain solid and/or liquid particles and that direct the solid and/or liquid particles toward jamb frames of the louver assembly. The jamb frames may then direct the solid and/or liquid particles out of the louver assembly and away from the HVAC system or enclosed space. However, openings of the louver assembly formed between adjacent louver blades may be configured to enable sufficient air flow through the louver assembly, for example, to enable the HVAC system to operate desirably. 
     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, which includes an outdoor HVAC unit and an indoor HVAC unit. 
     The HVAC unit  12  in the illustrated embodiment is an air cooled device that implements a refrigeration or vapor compression 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  10 . 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  10  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 . 
     As discussed above, the present disclosure is directed to a louver assembly that includes a frame or a frame assembly and louver blades having a geometry that enables desired amounts of air flow through the louver assembly while also blocking solid and/or liquid particles from flowing through the louver assembly. For example, the louver blades may include extensions that form recesses configured to receive, capture, or retain solid and/or liquid particles. The louver blades may also include features, such as protrusions, that retain the solid and/or liquid particles within the recesses. The frame or frame assembly may include a jamb frame coupled to the louver blades. The jamb frame may have channels that align with the recesses of the louver blades, and the channels may receive the solid and/or liquid particles captured or retained by the louver blades via the recesses. The channels may then discharge the solid and/or liquid particles out of the louver assembly. Further, the louver blades may be arranged to form openings between adjacent louver blades that enable air to flow through the louver assembly at a desirable flow rate. In this manner, the louver blades may enable improved control of air flow through the louver assembly. 
     With this in mind,  FIG. 2  is a perspective view of an embodiment of a louver or a louver assembly  50  that may be incorporated in an HVAC system. For example, the louver assembly  50  may be positioned to control air flow between an ambient environment and an enclosed space, such as an interior of the HVAC unit  12 . The air flow may be drawn into the HVAC unit  12  (e.g., for cooling refrigerant, for use as a supply air flow directed to a space conditioned by the HVAC unit  12 ) and/or may be discharged from the HVAC unit  12  (e.g., after use in conditioning the space conditioned by the HVAC unit  12 ). The louver assembly  50  may include a frame assembly  52  (e.g., a frame) defining an air flow path through the louver assembly  50  (e.g., from an upstream location to a downstream location). It should be noted that “upstream,” “midstream,” and “downstream” may be utilized herein with reference to a direction of air flow through the louver assembly  50 . In some embodiments, the frame assembly  52  may include multiple frame members that are coupled one another to define a perimeter of the air flow path or the louver assembly  50 . As an example, the frame assembly  52  may include jamb or lateral frames or frame members  54  defining a portion of the perimeter of the air flow path. Each of the jamb frames  54  may be configured to couple to a head or top frame or frame member  55  and to a sill or base frame or frame member  56 . Each of the head frame  55  and the sill frame  56  may define additional portions of the perimeter of the air flow path. The jamb frame  54 , the head frame  55 , and the sill frame member  56  are coupled to one another to form a rectangular geometry in the illustrated frame assembly  52 . However, in additional or alternative embodiments, the frame assembly  52  may have any other suitable geometry, such as a triangular shape, a trapezoidal shape, a diamond shape, a circular shape, and so forth, and/or may include any suitable number of frames defining the geometry (e.g., a perimeter) of the frame assembly  52 . In any case, the frame assembly  52  may form an opening  60  through which air may flow. 
     The louver assembly  50  may further include blades or louver blades  58  that are coupled to the frame assembly  52 , such as to the jamb frames  54 . Each of the louver blades  58  may span across the opening  60 . Indeed, the louver blades  58  may be configured to block solid and/or liquid particles (e.g., solid and/or liquid particles carried by the air flow) from passing through the louver assembly  50  via the opening  60 . For example, the louver blades  58  may block precipitation, dust, dirt, and/or debris from flowing through the opening  60 . In certain embodiments, the position of the louver blades  58  may remain fixed relative to the frame assembly  52 . That is, louver blades  58  may not move relative to the frame assembly  52  in an assembled configuration of the louver assembly  50 . As such, the louver blades  58  may be shaped to block the flow of the solid and/or liquid particles through the opening  60 . For instance, as further discussed herein, the louver blades  58  may be configured to trap solid and/or liquid particles and to guide the particles toward the jamb frames  54 , and the jamb frames  54  may be configured to guide the solid and/or liquid particles to flow out of the louver assembly  50  (e.g., into the ambient environment and away from an interior of the HVAC unit  12 ) in an installed configuration of the louver assembly  50 . For example, the jamb frames  54  may direct the solid and/or liquid particles onto a surface  62  of the sill frame  56  via a gravitational force, and the surface  62  may direct the solid and/or liquid particles away from the louver assembly  50  via an opening formed between the sill frame  56  and an adjacent louver blade  58 . Additionally, the louver blades  58  may enable air flow through the louver assembly  50  via the opening  60 , which may enable efficient operation of the HVAC unit  12 . Indeed, openings formed between the louver blades  58  may permit a desired amount or quality of air flow through the louver assembly  50 . 
       FIG. 3  is an exploded perspective view of an embodiment of the louver assembly  50 . In the illustrated embodiment, the jamb frames  54 , the head frame  55 , and the sill frame  56 , and are separate components configured to couple to one another. For example, fasteners may be used to couple the frames  54 ,  56 ,  55  to one another to form the frame assembly  52 . Further, each of the louver blades  58  may be configured to couple to the jamb frames  54 . As an example, opposite ends of each louver blade  58  may be coupled to a respective jamb frame  54  in the assembled configuration of the louver assembly  50 . In the manner described below, solid and/or liquid particles trapped by the louver blades  58  may be guided toward the ends of the louver blades  58  and to the jamb frames  54 . The jamb frames  54  may then guide the solid and/or liquid particles onto the sill frame  56  and away from the louver assembly  50 . 
       FIG. 4  is a partial perspective view of an embodiment of one of the louver blades  58  of the louver assembly  50 . The louver blade  58  may include a first side, profile, or surface  100  (e.g., a top of the louver blade  58 ) and a second side, profile, or surface  102  (e.g., a bottom or underside of the louver blade  58 ) opposite the first side  100 . Each of the first side  100  and the second side  102  may have or define geometries and features that block solid and/or liquid particles from passing through the louver assembly  50 . For example, a first section  104  (e.g., an upstream or front section) of the louver blade  58  may include an incline portion  106  that is oriented at an angle  108  (e.g., an angle between 20 degrees and 60 degrees) relative to a horizontal axis  110  extending through the louver assembly  50 . The incline portion  106  may create a barrier (e.g., of the first side  100 ) configured to block a flow of solid and/or liquid particles and deflect the solid and/or liquid particles away from the louver assembly  50 , such as away from a space downstream of the louver assembly  50  (e.g., the interior of an HVAC system). In some embodiments, the first section  104  may also include a first extension  112  extending from a first distal or upstream end  114  (e.g., along a vertical axis  116 ) of the incline portion  106  to block solid and/or liquid particles flowing toward the incline portion  106 . The first extension  112  may also form a first recess  118  in the first side  100  between the first extension  112  and the incline portion  106 . Thus, solid and/or liquid particles may impinge impact the incline portion  106 , and the incline portion  106  may direct the solid and/or liquid particles to flow into the first recess  118  via a gravitational force. The first recess  118  may then guide the solid and/or liquid particles to flow toward the jamb frames  54  and out of the louver assembly  50  (e.g., instead of onto an adjacent louver blade  58 ). 
     The louver blade  58  may also include a first protrusion or finger  120  extending from the incline portion  106  on the second side  102  to form a hook profile  122  that is shaped to block additional solid and/or liquid particles from flowing across the louver blade  58  and through the louver assembly  50 . By way of example, the hook profile  122  may capture mist that may be formed from precipitation flowing between the louver blade  58  and an adjacent louver blade  58 . The mist may accumulate to form water droplets on the hook profile  122 , and the hook profile  122  may direct the water droplets out of the louver assembly  50 , such as toward the first recess  118  of an adjacent louver blade  58 , via the gravitational force. In the illustrated embodiment, the first protrusion  120  is adjacent to (e.g., cooperatively forms) a first feature  124  (e.g., a screw boss, a protrusion, a retention passage) configured to receive a fastener to couple or mount the louver blade  58  to one of the jamb frames  54 . In additional or alternative embodiments, the first protrusion  120  and the first feature  124  may be separate from one another. As an example, the first feature  124  may extend from the incline portion  106  on the first side  100  of the louver blade  58 , and the first protrusion  120  may extend from the incline portion  106  on the second side  102  of the louver blade  58 . 
     The louver blade  58  may include a second section  126  (e.g., a middle or midstream section) that includes additional features configured to block the flow of solid and/or liquid particles through the louver assembly  50 . In the illustrated embodiment, the incline portion  106  may form a crest  128  (e.g., a peak) with a decline portion  130  of the louver blade  58 , and the first section  104  may transition to the second section  126  at the crest  128 . That is, the first section  104  may include the incline portion  106 , and the second section  126  may include a portion of the decline portion  130 . The second section  126  may include a second extension  132  extending from the decline portion  130  to form a second recess  134  between the decline portion  130  and the second extension  132 . Indeed, the second extension  132  may extend from the decline portion  130  at an angle between the horizontal axis  110  and the vertical axis  116 . The second recess  134  may capture additional solid and/or liquid particles, such as solid and/or liquid particles deflected off the incline portion  106 , and the second extension  132  may guide the solid and/or liquid particles into the second recess  134 . Indeed, the second extension  132  may also extend (e.g., linearly extend) toward the first section  104  and over the crest  128  to form the second recess  134 . In other words, the second extension  132  may extend in an upstream direction relative to a direction of air flow across the louver blade  58   
     The second section  126  may include various features to retain solid and/or liquid particles within the second recess  134 . For example, a second protrusion or finger  135  may extend from the second extension  132  at an angle and may be sized to guide solid and/or liquid particles (e.g., precipitation) to flow into the second recess  134  and block solid and/or liquid particles (e.g., mist) from flowing out of the second recess  134 . A third protrusion or finger  136  may extend from the crest  128  or the decline portion  130  at an angle and distance, such that the third protrusion  136  also guides solid and/or liquid particles to flow into the second recess  134  and blocks solid and/or liquid particles from flowing out of the second recess  134 . The second protrusion  135  and the third protrusion  136  may cooperatively retain the solid and/or liquid particles within the second recess  134 , and the second recess  134  may then direct the solid and/or liquid particles to the jamb frames  54  for discharge from the louver assembly  50 . That is, the second protrusion  135  and/or the third protrusion  136  may increase a retention capacity of the second recess  135 . 
     The louver blade  58  may further include a third section  138  (e.g., a downstream or tail section) having the second extension  132  extending from the decline portion  130 . The third section  138  may include a portion of the decline portion  130  and a second feature  140  (e.g., a screw boss, a protrusion, a retention passage) formed in the decline portion  130  and configured to receive a fastener to couple the louver blade  58  to one of the jamb frames  54 . A third extension  142  may extend from a second or downstream distal end  144  of the decline portion  130  on the first side  100 . The second feature  140  and the third extension  142  may form a third recess  146  on the first side  100 . The third recess  146  may be configured to capture solid and/or liquid particles, such as solid and/or liquid particles deflected off or directed by the second extension  132  and/or the decline portion  130 . Furthermore, the third section  138  may include a fourth extension  148  extending from the second distal end  144  of the decline portion  130  and forming a fourth recess  150  on the second side  102 . The fourth recess  150  may have a hook geometry configured to capture and retain solid and/or liquid particles flowing adjacent to the second side  102 , such as along the underside of the louver blade  58 . Each of the third recess  146  and the fourth recess  150  may direct the solid and/or liquid particles toward the jamb frames  54  and out of the louver assembly  50 . 
       FIG. 5  is an axial view of an embodiment of adjacent louver blades  58  of the louver assembly  50 . The illustrated louver blades  58  have substantially identical geometries. In additional or alternative embodiments, louver blades  58  may have different geometries. The adjacent louver blades  58  may form an air flow path  170  between the louver blades  58  and through the louver assembly  50 . For example, air (e.g., supply air) may flow underneath a first louver blade  58 A and above a second louver blade  58 B. Further, the recesses  118 ,  134 ,  146 ,  150  of each louver blade  58  may capture solid and/or liquid particles flowing along the air flow path  170  to block the solid and/or liquid particles from passing through the louver assembly  50  (e.g., into an HVAC system or other space). 
     The louver blades  58  may be positioned relative to one another to block solid and/or liquid particles (e.g., a substantial amount of solid and/or liquid particles to which the louver assembly  50  is exposed) while enabling a desirable amount of air to flow through the louver assembly  50 . For instance, each of the louver blades  58  may have a first height  172  extending from the first distal end  114  of the incline portion  106  along the vertical axis  116  to the second extension  132 . The louver blades  58  may be positioned relative to one another such that a second height  174  of a first opening  176  (e.g., an inlet of the louver assembly  50 ) formed between the first distal end  114  of the first louver blade  58 A and the first extension  112  (e.g., a top of the first extension  112 ) of the second louver blade  58 B is between approximately 40 percent to 65 percent of the first height  172 . Furthermore, a third height  178  of a second opening  180  (e.g., an outlet of the louver assembly  50 ) formed between the fourth extension  148  (e.g., a bottom or trough of the fourth extension  148 ) of the first louver blade  58 A and the third extension  142  of the second louver blade  58 B may be between approximately 25 percent and 50 percent of the first height  172 . To this end, a third height  182  between the first distal end  114  and the fourth extension  148  of the same louver blade  58  (e.g., the first louver blade  58 A in  FIG. 5 ) may be between approximately 25 percent and 35 percent of the first height  172 . The relative positioning of the louver blades  58  may provide desirable blocking of solid and/or liquid particles through the louver assembly  50  while limiting pressure drop and/or undesired restriction of air flow through the louver assembly  50 . Indeed, the arrangement of the louver blades  58  having the features described herein may block solid and/or liquid particles from flowing through the louver assembly  50  without incorporation of additional components, such as actuatable dampers, grilles, screens, and the like, that may increase the cost, complexity, weight, and so forth, of the louver assembly  50 . 
       FIG. 6  is an axial view of an embodiment of the head frame the head frame  55  and an adjacent louver blade  58  of the louver assembly  50 . The head frame  55  may include a first side or profile  200  (e.g., a top side or profile) and a second side or profile  202  (e.g., a bottom side or profile) opposite the first side  200 . The first side  200  may include support segments  204  having hook portions that may be used for installation and/or assembly of the louver assembly  50 . For instance, the support segments  204  may at least partially form a channel  206 , and the support segments  204  may capture a support (e.g., an enclosure of the HVAC system, a structure of a building, etc.) and secure the support within the channel  206  in order to couple the louver assembly  50  to the support via the head frame  55 . 
     The head frame  55  may have one or more features similar to or corresponding with the adjacent louver blade  58  (e.g., the second side  102  the louver blade  58  discussed above with reference to  FIG. 4 ). For example, the head frame  55  includes a first section  207  (e.g., a front section) having an  210 , a first extension  212  extending from a first or upstream distal end  214  of the incline portion  210  to form a first recess  216  configured to retain solid and/or liquid particles, a first feature  218  (e.g., a screw boss, a protrusion, a retention passage) extending from the incline portion  210  on the second side  202  of the head frame  55  and configured to receive a fastener for coupling the head frame  55  to one of the jamb frames  54 , and a first protrusion  220  extending from the incline portion  210  adjacent to the first feature  218  on the second side  202  of the head frame  55 . The incline portion  210  may form a crest  222  at a second section  223  (e.g., middle or midstream section) of the head frame  55 . The second section  223  may include a decline portion  224  extending from the crest  222 . A second feature  226  (a screw boss, a protrusion, a retention passage) is formed along the decline portion  224  on the first side  200  of the head frame  55  and is configured to receive a fastener to couple the head frame  55  to one of the jamb frames  54 . Further still, the head frame  55  includes a third section  227  (e.g., downstream or tail section). The third section  227  may include a second extension  228  extending from a second or downstream distal end  230  of the decline portion  224  on the second side  202  of the head frame  55  to form a second recess  232  configured to retain solid and/or liquid particles. In the illustrated embodiment, one of the support segments  204  extends from the incline portion  210  and therefore may block solid and/or liquid particles and/or air from flowing between the incline portion  210  and the support segment  204 , thereby blocking solid and/or liquid particles and/or air from flowing between the head frame  55  and the support to which the louver assembly  50  is coupled. Further, the other of the support segments  204  may extend from the second distal end  230 , as shown. 
     The head frame  55  may be positioned relative to the adjacent louver blade  58  in a similar manner in which adjacent louver blades  58  are positioned relative to one another. That is, a first opening  234  (e.g., an inlet of the louver assembly  50 ) may be formed between the first distal end  214  of the head frame  55  and the first extension  112  (e.g., a top or distal end of the first extension  112 ) of the adjacent louver blade  58 . As similarly discussed above, the first opening  234  may have a height that is between approximately 40 percent and 65 percent of the first height  172  of the louver blade  58 . Furthermore, a second opening  236  (e.g., an outlet of the louver assembly  50 ) may be formed between the second extension  228  (e.g., a bottom or trough of the second extension  228 ) and the third extension  142  of the adjacent louver blade  58 . The second opening  236  may have a height that is between approximately 25 percent and 50 percent of the first height  172  of the louver blade  58 . Indeed, the head frame  55  and the adjacent louver blade  58  may form an air flow path  238  through which air may flow while also blocking solid and/or liquid particles from flowing through the louver assembly  50 . 
     The louver blades  58  discussed herein may each be formed as a single integral piece. For instance, the louver blades  58  may be formed via welding, bending, molding, and the like. In additional or alternative embodiments, the louver blades  58  may be formed from separate pieces that are coupled to one another, such as via fasteners, an adhesive, an interference fit, or any combination thereof. Further, the louver blades  58  may be formed from a material that is suitable for resisting impact of particles. For example, the louver blades  58  may be formed from a metal, a ceramic, an alloy or composite material, a polymer, or any combination thereof, having a suitable strength and rigidity to withstand various environmental conditions and flow or impact forces of solid and/or liquid particles. 
       FIG. 7  is an axial view of an embodiment of the sill frame  56  and an adjacent louver blade  58 . The illustrated sill frame  56  includes a base  260  and support segments  262  extending from the base  260 . The support segments  262  may each be hook-shaped to at least partially form a channel  264 , and the support segments  262  may capture a support or other structure. In this way, the support may be secured within the channel  264  to couple the louver assembly  50  to the support via the sill frame  56 . The sill frame  56  may also include a mounting segment  266  extending from the base  260 . In an assembled configuration of the louver assembly  50 , the sill frame  56  may abut against the fourth extension  148  of the adjacent louver blade  58 , thereby blocking flow of air and solid and/or liquid particles through the louver assembly  50  between the adjacent louver blade  58  and the sill frame  56 . 
     Furthermore, the above-described engagement between the sill frame  56  and the adjacent louver blade  58  may form a cavity  268  defined by the sill frame  56  and the adjacent louver blade  58 . The cavity  268  may receive solid and/or liquid particles (e.g., precipitation), such as solid and/or liquid particles captured by the louver blades  58  and directed into the jamb frames  54 . That is, solid and/or liquid particles within the jamb frames  54  may be discharged into the cavity  268 . An opening  270  may be formed between the base  260  and the first distal end  114  of the adjacent louver blade  58  to enable the solid and/or liquid particles to flow out of the cavity  268 . For instance, the solid and/or liquid particles received from the jamb frames  54  may accumulate on a surface  272  of the base  260  and may flow out of the opening  270  (e.g., into an ambient environment). In the illustrated embodiment, the base  260  is substantially level or parallel with the horizontal axis  110 . However, in additional or alternative embodiments, the base  260  may be positioned at an angle relative to the horizontal axis  110 , such as at an angle to direct the solid and/or liquid particles out of the cavity  268  through the opening  270  via gravitational force. 
       FIG. 8  is a top view of an embodiment of the jamb frame  54 . In some embodiments, each of the jamb frames  54  (e.g., the jamb frames  54  positioned at either lateral side of the louver assembly  50 ) may have a similar, such as a mirrored, geometry. In additional or alternative embodiments, the jamb frames  54  of the louver assembly  50  may have different geometries. The illustrated jamb frame  54  includes base segments  290  that extend along a first axis  292  (e.g., the horizontal axis  110 , a flow direction through the louver assembly  50 , etc.). Each of the base segments  290  may also be aligned with one another relative to a second axis  294  (e.g., the base segments  290  extend along a common axis that is generally parallel to the first axis  292 ) and may be configured to abut the sill frame  56 , the head frame  55 , and the louver blades  58  in an assembled configuration of the louver assembly  50 . 
     Further, the jamb frame  54  may include a first channel  296 , a second channel  298 , and a third channel  300 . In the assembled configuration of the louver assembly  50 , the first channel  296  may be aligned with the respective first recesses  118  of the louver blades  58  relative to the first axis  292  or a direction of air flow through the louver assembly  50  (e.g., the first channel  296  and the first recesses  118  are positioned along a common axis extending generally parallel to the second axis  294 ) and may be configured to receive solid and/or liquid particles captured and directed thereto by the first recesses  118 . In addition, the second channel  298  may be aligned with the respective second recesses  134  of the louver blades  58  relative to the first axis  292  or a direction of air flow through the louver assembly  50  (e.g., the second channel  298  and the second recesses  134  are positioned along a common axis extending generally parallel to the second axis  294 ) and may be configured to receive solid and/or liquid particles captured and directed thereto by the second recesses  134 . Further, the third channel  300  may be aligned with the respective third recesses  146  and the fourth recesses  150  of the louver blades  58  relative to the first axis  292  or a direction of air flow through the louver assembly  50  (e.g., the third channel  300  and the third recesses  146  are positioned along a common axis extending generally parallel to the second axis  294 ) and may be configured to receive solid and/or liquid particles captured and directed thereto by each of the third recesses  146  and the fourth recesses  150 . Each of the channels  296 ,  298 ,  300  may guide the solid and/or liquid particles received from the louver blades  58  toward the sill frame  56  for removal from the louver assembly  50  in the installed configuration. Although the illustrated channels  296 ,  298 ,  300  have rectangular geometries, additional or alternative embodiments of the channels  296 ,  298 ,  300  may have any suitable shape to receive and direct solid and/or liquid particles. 
     The illustrated jamb frame  54  also includes protrusions or fingers  302 , which may extend into the first channel  296  at an angle (e.g., relative to the second axis  294 ). The protrusions  302  may be oriented to guide the solid and/or liquid particles into the first channel  296  while blocking the solid and/or liquid particles from traveling out of the first channel  296  in the installed configuration. Thus, the protrusions  302  may improve guidance of the solid and/or liquid particles into and through the first channel  296  to be directed out of the louver assembly  50 . Additional or alternative embodiments of the jamb frame  54  may include protrusions  302  extending into any of the other channels  298 ,  300  to improve guidance of the solid and/or liquid particles into and through the other channels  298 ,  300 . 
       FIG. 9  is an axial view of an embodiment of louver blades  320  that may be incorporated in the louver assembly  50 . Each of the louver blades  320  in the illustrated embodiment has a similar geometry. In additional or alternative embodiments, different louver blades  320  in the louver assembly  50  may have different geometries. As an example, each louver blade  320  may include a first section  322  (e.g., an upstream or front section) that may have a first segment  324  (e.g., linear, planar, and/or generally horizontal segment). Each louver blade  320  may also include a first side  321  (e.g., a profile on a top side of the louver blade  320 ) having a first extension  326  extending from a first or upstream distal end  328  of the first segment  324  (e.g., generally along the vertical axis  116 ). Thus, the first segment  324  and the first extension  326  may cooperatively form a first recess  330  between the first segment  324  and the first extension  326  on the first side  321  of the louver blade  320 . As similarly described above, the first recess  330  is configured to retain solid and/or liquid particles captured by the louver assembly  50  and to direct the solid and/or liquid particles toward the jamb frames  54 . Each of the illustrated louver blades  320  also includes a first feature  332  (e.g., a screw boss, a protrusion, a retention passage) extending from the first segment  324  on the first side  321 . The first features  332  may receive respective fasteners to couple the louver blades  320  to one of the jamb frames  54 . 
     Each of the louver blades  320  may also include a second section  333  (e.g., a middle or midstream section) that includes an incline portion  334  extending from the first feature  332  and/or the first segment  324 . The incline portion  334  may shaped (e.g., angled, curved) to block flow of solid and/or liquid particles through the louver assembly  50  and/or to direct solid and/or liquid particles toward the first recess  330 . The incline portion  334  may form a crest  336 , and a decline portion  338  of the second section  333  may extend from the crest  336  and transition into a second segment  340  (e.g., linear, planar, and/or generally horizontal segment). In some embodiments, the decline portion  338  may extend to or beyond (e.g., below) a level of the first segment  324 , such that the second segment  340  is level with or below the first segment  324  along the vertical axis  116 . 
     A second extension  342  may extend from the second segment  340  to form a second recess  344  between the second extension  342  and the decline portion  338  on the first side  321  of the louver blade  320 . In the illustrated embodiment, the second extension  342  has a curved geometry that may extend over the crest  336  relative to the vertical axis  116  and beyond the crest  336  along the horizontal axis  110  (e.g., in an upstream direction), thereby blocking or capturing solid and/or liquid particles that may deflect off the incline portion  334 , the crest  336 , and/or the decline portion  338 . Further, the crest  336  may facilitate guidance of solid and/or liquid particles into, and retention of solid and/or liquid particles within, the second recess  344 . The second recess  344  may direct the solid and/or liquid particles toward the jamb frames  54  in the installed configuration of the louver assembly  50 . Each of the illustrated louver blades  320  further includes a second feature  346  (e.g., a screw boss, a protrusion, a retention passage) extending from the second extension  342 , such as toward the second recess  344 . The second features  346  may also receive respective fasteners to couple the louver blades  320  to one of the jamb frames  54 . In addition, the second features  346  may also block solid and/or liquid particles (e.g., mist) from flowing out of the second recess  344 , thereby facilitating the capture of the solid and/or liquid particles within the second recess  344  during use of the louver assembly  50  and increasing a retention capacity of the second recess  344 . 
     Each of the louver blades  320  may further include a third section  347  (e.g., a downstream or tail section) having a third extension  348  extending from a second or downstream distal end  350  of the second segment  340  on the first side  321  of the louver blade  320  to form a third recess  352  between the second segment  340  and the third extension  348  on the first side  321 . The third extension  348  may block or capture solid and/or liquid particles, such as solid and/or liquid particles directed over the second extension  342 . Indeed, the third extension  348  may include a hook shape to increase a retention capacity of the third recess  352 , and the third recess  352  may direct the solid and/or liquid particles toward the jamb frames  54 . Moreover, each of the louver blades  320  may include a fourth extension  354  extending from the second segment  340  and forming a fourth recess  358  between the second segment  340  and the fourth extension  354  on a second side  360  of the louver blade  320  (e.g., a bottom side opposite the first side  321 ). The fourth extension  354  may include a hook shape to increase a retention capacity of the fourth recess  358 . For instance, the fourth extension  354  may extend upstream and curve upwards (e.g., at a position vertically aligned with the crest  336 ) to block captured solid and/or liquid particles from flowing out of the fourth recess  358 , thereby retaining the solid and/or liquid particles within the fourth recess  358 . Indeed, the fourth extension  354  may extend to overlap (e.g., vertically overlap) with the decline portion  338  along the vertical axis  116  (e.g., an axis crosswise to a direction of air flow through the louver assembly  50 ) so as to capture solid and/or liquid particles within the fourth recess  358  that deflect off the incline portion  334 , the crest  336 , the decline portion  338 , or any combination thereof, on the second side  360  of the louver blade  320 . The fourth recess  358  may direct the solid and/or liquid particles to the jamb frames  54  for removal from the louver assembly  50  in the manner described above. 
     In the illustrated embodiment, each of the louver blades  320  includes a third feature  362  (e.g., a screw boss, a protrusion, a retention passage) extending from the fourth extension  354  (e.g., toward the second segment  340 ) and configured to receive a fastener configured to couple the louver blade  320  to one of the jamb frames  54 . The third feature  362  may also extend toward or into the fourth recess  358  and may be configured to block solid and/or liquid particles from flowing out of the fourth recess  358 , thereby further facilitating capture of the solid and/or liquid particles within the fourth recess  358 . 
     It should be noted that any of the features  332 ,  346 ,  362  may be positioned along the louver blade  320  at different locations or orientations in additional or alternative embodiments of the louver blade  320 . For instance, the first feature  332  may be disposed on the second side  360 , the third feature  362  may extend from the fourth extension  354 , and so forth. In further embodiments, the louver blade  320  may include a different number of features, such as two features or more than three features configured to enable coupling of the louver blade  320  to the jamb frames  54 . 
     The illustrated adjacent louver blades  320  form a first opening  364  (e.g., an inlet of the louver assembly  50 ) between the first distal end  328  of a first louver blade  320 A and the first extension  326  (e.g., a top of the first extension  326 ) of a second louver blade  320 B. Further, the fourth extension  354  of the first louver blade  320 A may overlap (e.g., vertically overlap) with the second extension  342  along the vertical axis  116  and may therefore extend over the second extension  342  of the second louver blade  320 B to form a second opening  366  (e.g., a neck). The adjacent louver blades  320  may also form a third opening  368  (e.g., an outlet of the louver assembly  50 ) between the second distal end  350  of the first louver blade  320 A and the third extension  348  (e.g., a top of the third extension  348 ) of the second louver blade  320 B. In this manner, the louver blades  320  may enable air to flow through the louver assembly  50  along an air flow path  370  extending through the first opening  364 , the second opening  366 , and the third opening  368  while the features of the louver blades  320  described above enable capture, retention, and discharge of liquid and/or solid particles directed into the louver assembly  50 . 
     The louver assembly  50  incorporating the louver blades  320  may also have a differently shaped head frame  55 , jamb frame  54 , and/or sill frame  56  than those described above. By way of example, the head frame  55  may include a second side  202  having features corresponding with those of the second side  360  of the louver blade  320  rather than those of the second side  102  of the louver blade  58  described with respect to  FIG. 4 . Additionally or alternatively, the jamb frame  54  may include channels that are positioned and/or shaped to align with the recesses  330 ,  344 ,  352 ,  358 , thereby enabling the jamb frame  54  to receive solid and/or liquid particles captured and directed by the louver blades  58  and to direct the solid and/or liquid particles out of the louver assembly  50 . 
       FIG. 10  is an axial view of an embodiment of a louver blade  380  that may be incorporated in the louver assembly  50 . The louver blade  380  may have a similar geometry as any of the louver blades described above, such as one of the louver blades  320  described with respect to  FIG. 9 . However, the illustrated louver blade  380  includes separate pieces that are coupled to one another. By way of example, the second segment  340  of the louver blade  380  may include first formations  382  (e.g., ridges, ribs, etc.). The first formations  382  may be configured to receive an end  384  of the second extension  342  to couple the second extension  342  and the second segment  340  to one another. For instance, the first formations  382  may compress against the end  384  via an interference fit, thereby securing the second extension  342  and the second segment  340  to one another. Furthermore, the second segment  340  may include second formations  386  (e.g., ridges, ribs, etc.) configured to receive third formations  388  (e.g., ridges, ribs, etc.) of the fourth extension  354 , thereby coupling the second segment  340  and the fourth extension  354  to one another, such as via an interference fit. Additionally or alternatively, a fastener, an adhesive, or other bonding technique may be used to couple the second extension  342  and the second segment  340  to one another and/or to couple the second segment  340  and the fourth extension  354  to one another. 
     It should be noted that any of the features illustrated and/or described herein may be incorporated with one another. For example, the louver assembly  50  may have louver blades that include any combination of the described extensions, protrusions, features, and so forth, as well as a jamb frame shaped to receive particles from the louver blade. Indeed, the louver blade of the louver assembly  50  may have formations that are shaped and sized increase a retention capacity of recesses for directing toward the jamb frame while enabling desirable air flow rate through the louver assembly  50 . 
     The present disclosure may provide one or more technical effects useful in the operation of an HVAC system. For example, the HVAC system may include a louver assembly configured to enable air flow between an interior and an exterior of an HVAC system or other enclosed space. The louver assembly may include louver blades having features configured to block solid and/or liquid particles from passing through the louver assembly, thereby blocking the solid and/or liquid particles from entering the HVAC system or enclosed space. In some embodiments, each louver blade may include various features, extensions, protrusions, and the like, that may block solid and/or liquid particles from flowing past the louver blade and through the louver assembly. Additionally, each louver blade may include one or more recesses configured to capture or retain the blocked solid and/or liquid particles and to direct the solid and/or liquid particles toward jamb frames configured to direct the solid and/or liquid particles out of the louver assembly. An opening may be formed between adjacent louver blades to form an air flow path permitting air to flow through the louver assembly. Indeed, the louver blades may permit air to flow through the louver assembly at a desirable flow rate, such as to enable efficient operation of an HVAC system. The technical effects and technical problems in the specification are examples and are not limiting. 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 disclosure 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, including 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 of carrying out the disclosure, or those unrelated to enabling the claimed disclosure. It should be noted 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.