Systems and methods for protecting HVAC componentry from contamination and / or corrosion

Abstract

A heating, ventilation, and / or air conditioning (HVAC) system includes a compressor section corresponding to a compressor, an additional section corresponding to at least an end portion of a heat exchanger, and a front coil block-off (FCBO) box configured to fluidly isolate the additional section from the compressor section, the additional section from an ambient environment, or both.

Description

BACKGROUND

[0001] 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 and / or claimed 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.

[0002] The present disclosure relates generally to heating, ventilation, and air conditioning (HVAC) systems. A wide range of applications exist for HVAC systems. For example, residential, light commercial, commercial, and industrial systems are used to control temperatures and air quality in residences and buildings. Such systems often may perform heating and / or cooling functions. Very generally, these systems operate by implementing a thermal cycle in which fluids are heated and / or cooled to provide a desired temperature in a controlled space, such as within a residence or building. For example, a heat exchanger may include a coil, such as an indoor coil, configured to receive and place a fluid, such as a refrigerant, in a heat exchange relationship with an air flow to enable heat transfer between the fluid and the air flow in order to condition the air flow. The conditioned air flow may then be directed into the controlled space to condition the controlled space. A compressor of the HVAC system may be configured to bias the fluid, such as the refrigerant, to and from the heat exchanger, in addition to other componentry of the HVAC system (e.g., an additional heat exchanger, an expansion valve, etc.).

[0003] In traditional configurations, such as traditional single package HVAC units, HVAC componentry may include various components having dissimilar metals, such as copper components and aluminum components, that share a substantially common space or are otherwise disposed in spaces in fluid communication with one another and / or an ambient environment. For these and / or other reasons, rain, moisture, condensate, and / or other liquids may migrate between the aluminum components and the copper components, which may lead to undesirable corrosion (e.g., galvanic corrosion). Accordingly, it is now recognized that improved systems and methods are desired.SUMMARY

[0004] A summary of an embodiment disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of the embodiment 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.

[0005] In an embodiment, a heating, ventilation, and / or air conditioning (HVAC) system includes a compressor section corresponding to a compressor, an additional section corresponding to at least an end portion of a heat exchanger, and a front coil block-off (FCBO) box configured to fluidly isolate the additional section from the compressor section, the additional section from an ambient environment, or both.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[0007] FIG. 1 is a perspective view of an embodiment of a heating, ventilation, and / or air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units, in accordance with aspects of the present disclosure;

[0008] FIG. 2 is a perspective view of an embodiment of an HVAC unit of the HVAC system of FIG. 1, in accordance with aspects of the present disclosure;

[0009] FIG. 3 is a perspective view of an embodiment of a residential split heating and cooling system, in accordance with aspects of the present disclosure;

[0010] FIG. 4 is a schematic view of an embodiment of a vapor compression system that may be used in an HVAC system, in accordance with aspects of the present disclosure;

[0011] FIG. 5 is a schematic block diagram of an embodiment of an HVAC unit, such as a single package HVAC unit (e.g., a single package residential HVAC unit), including a front coil block-off (FCBO) box, in accordance with aspects of the present disclosure;

[0012] FIG. 6 is a perspective view of an embodiment of the single package HVAC unit of FIG. 5, in accordance with aspects of the present disclosure;

[0013] FIG. 7 is a perspective view of an embodiment of the single package HVAC unit of FIG. 5 with a panel portion of a housing removed to illustrate componentry inside of the housing, in accordance with aspects of the present disclosure;

[0014] FIG. 8 is a perspective view of an embodiment of the single package HVAC unit of FIG. 5 with multiple panel portions of a housing removed to illustrate componentry inside of the housing, in accordance with aspects of the present disclosure;

[0015] FIG. 9 is a perspective view of an embodiment of the single package HVAC unit of FIG. 5 with multiple panel portions of a housing removed and multiple portions of the FCBO box removed to illustrate componentry inside of the housing, in accordance with aspects of the present disclosure;

[0016] FIG. 10 is a partially disassembled perspective view of an embodiment of the single package HVAC unit of FIG. 5 illustrating a compressor barrier block-off wall and an additional wall configured to be coupled to (e.g., mounted to) the compressor barrier block-off wall, in accordance with aspects of the present disclosure;

[0017] FIG. 11 is another partially disassembled perspective view of an embodiment of the single package HVAC unit of FIG. 5, illustrating a compressor barrier block-off wall and an additional wall configured to be coupled to (e.g., mounted to) the compressor barrier block-off wall, in accordance with aspects of the present disclosure;

[0018] FIG. 12 is a partially disassembled perspective view of an embodiment of the single package HVAC unit of FIG. 5, illustrating an L-shaped FCBO panel of the FCBO box and a thermostatic expansion valve (TXV) disposed in a space at least partially defined by the L-shaped FCBO panel, in accordance with aspects of the present disclosure; and

[0019] FIG. 13 is a perspective cross-sectional view of an embodiment of the single package HVAC unit.DETAILED DESCRIPTION

[0020] 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 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' 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.

[0021] 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.

[0022] As used herein, the terms “approximately,”“generally,”“substantially,” and so forth, are intended to convey that the property value being described may be within a relatively small range of the property value, as those of ordinary skill would understand. For example, when a property value is described as being “approximately” equal to (or, for example, “substantially similar” to) a given value, this is intended to convey that the property value may be within + / −5%, within + / −4%, within + / −3%, within + / −2%, within + / −1%, or even closer, of the given value. Similarly, when a given feature is described as being “substantially parallel” to another feature, “generally perpendicular” to another feature, and so forth, this is intended to convey that the given feature is within + / −5%, within + / −4%, within + / −3%, within + / −2%, within + / −1%, or even closer, to having the described nature, such as being parallel to another feature, being perpendicular to another feature, and so forth. Mathematical terms, such as “parallel” and “perpendicular,” should not be rigidly interpreted in a strict mathematical sense, but should instead be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art would understand that two lines that are substantially parallel to each other are parallel to a substantial degree, but may have minor deviation from exactly parallel.

[0023] The present disclosure is directed to heating, ventilation, and / or air conditioning (HVAC) units, such as a single package HVAC unit (e.g., a single package residential HVAC unit), including a compressor section corresponding to a compressor, an additional section corresponding to at least a portion of a heat exchanger (e.g., an end portion of an indoor coil), and a fluid isolation of the additional section from the compressor section and / or ambient environment. More specifically, the present disclosure is directed to a front coil block-off (FCBO) box configured to fluidly isolate the additional section, also referred to as an interior of the FCBO box, from the compressor section and / or the ambient environment. It should be understood that, in certain embodiments, only a portion of the heat exchanger extends into the additional section defined by the FCBO box. For example, the FCBO box may include (e.g., the FCBO box may be partially defined by) an end sheet of the heat exchanger, where tubing of the heat exchanger impinges the end sheet and extends into the additional section. Other portions of the FCBO box, such as a compressor barrier block-off wall, an L-shaped FCBO panel, a bracket (also referred to as an FCBO front cover), a drain pan, and / or panels of a housing of the single package HVAC unit, and other aspects of the present disclosure are described in detail below.

[0024] A single package HVAC unit may include various components having dissimilar metals. For example, certain components may include a first metallic material, such as copper, and certain other components may include a second metallic material different than the first metallic component, such as aluminum. In certain traditional configurations, such componentry may share a substantially common space or otherwise reside within spaces having at least some fluid communication there between. Such conditions render these traditional configurations susceptible to contamination of the aluminum components, for example, when liquid (e.g., rain, condensate, and / or other liquids) migrates from the copper components to the aluminum components, which may lead to corrosion (e.g., galvanic corrosion) of the contaminated surfaces of the aluminum components over time.

[0025] In accordance with embodiments of the present disclosure, components of a single package HVAC unit are selectively located, isolated, sealed off, and / or contained to negate, reduce, or mitigate the contamination and corrosion (e.g., galvanic corrosion) described above and associated with certain traditional configurations. For example, the FCBO box referenced above may be configured to isolate aluminum componentry in the additional section defined by the FCBO box, also referred to as the interior of the FCBO box, from copper componentry in the compressor section. For example, the FCBO box may at least partially seal an interface between the compressor section and the interior of the FCBO box (e.g., the additional section). Additionally or alternatively, the FCBO box may isolate the interior of the FCBO box (e.g., the additional section) from an ambient environment. Various gaskets, fasteners, and the like, as described in greater detail with reference to the drawings, may be employed to integrate the FCBO box in the single package HVAC unit and / or seal the interior of the FCBO box from the compressor section and / or the ambient environment.

[0026] Further, in some embodiments, copper components may reside or otherwise extend into the FCBO box, aluminum components may reside or otherwise extend into the compressor section, or both. The copper components in the interior of the FCBO box may be encased or covered (e.g., isolated from the aluminum components in the FCBO box) by one or more protective coverings (e.g., a heat shrink wrap, a sleeve such as a polypropylene sleeve, or the like), and the aluminum components in the compressor section may be encased or covered (e.g., isolated from the copper components in the compressor section) by one or more protective coverings (e.g., a heat shrink wrap, a sleeve such as a polypropylene sleeve, or the like). Additionally or alternatively, a brazed joint between an aluminum portion of a component and a copper portion of the component, such as a brazed joint in the compressor section between an aluminum portion of a header and a copper portion of a header, may be encased or covered by a protective covering (e.g., a heat shrink wrap, a sleeve such as a polypropylene sleeve, or the like). In this way, componentry of the single package HVAC unit is better protected from contamination and / or corrosion (e.g., galvanic corrosion) than certain traditional configurations. These and other aspects of the present disclosure are described in greater detail below with reference to the drawings.

[0027] Turning now to the drawings, FIG. 1 illustrates an embodiment of a heating, ventilation, and / or air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units. The HVAC system of FIG. 1 may also employ present embodiments to limit overflow of condensate into ductwork. 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 HVAC 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.

[0028] 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 heat exchanger of the HVAC unit 12, such as one in a refrigeration circuit, may cause generation of condensate that is collected and removed in accordance with embodiments of the presently disclosed drain system and shield.

[0029] 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.

[0030] 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 HVAC 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.

[0031] 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.

[0032] The HVAC unit 12 includes heat exchangers 28 and 30 in fluid communication with one or more refrigeration circuits. Such heat exchangers may cause accumulation of condensate from environmental air that is addressed by embodiments of the presently disclosed drainage system. Tubes within the heat exchangers 28 and 30 may circulate a working fluid, such as R-410A, through the heat exchangers 28 and 30. The tubes may be of various types, such as multichannel tubes, microchannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers 28 and 30 may implement a thermal cycle in which the working fluid 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 working fluid to ambient air, and the heat exchanger 30 may function as an evaporator where the working fluid 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.

[0033] The heat exchanger 30 is located within a compartment 31 that separates the heat exchanger 30 from the heat exchanger 28. Fans 32 draw air from the environment through the heat exchanger 28. Air may be heated and / or cooled as the air flows through the heat exchanger 28 before being released back to the environment surrounding the rooftop unit 12. A blower assembly 34, powered by a motor 36, draws air through the heat exchanger 30 to heat or cool the air. The heated or cooled air may be directed to the building 10 by the ductwork 14, which may be connected to the HVAC unit 12. Before flowing through the heat exchanger 30, the conditioned air flows through one or more filters 38 that may remove particulates and contaminants from the air. In certain embodiments, the filters 38 may be disposed on the air intake side of the heat exchanger 30 to prevent contaminants from contacting the heat exchanger 30.

[0034] The HVAC unit 12 also may include other equipment for implementing the thermal cycle. Compressors 42 increase the pressure and temperature of the working fluid before the working fluid 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.

[0035] 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.

[0036] FIG. 3 illustrates an embodiment of 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 working fluid 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 working fluid conduits 54 transfer working fluid between the indoor unit 56 and the outdoor unit 58, typically transferring primarily liquid working fluid in one direction and primarily vaporized working fluid in an opposite direction.

[0037] 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 working fluid flowing from the indoor unit 56 to the outdoor unit 58 via one of the working fluid conduits 54. In these applications, a heat exchanger 62 of the indoor unit functions as an evaporator. Specifically, the heat exchanger 62 receives liquid working fluid, which may be expanded by an expansion device, and evaporates the working fluid before returning it to the outdoor unit 58.

[0038] 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. In accordance with present embodiments, the indoor unit 56 includes a drain system in accordance with the present disclosure to limit or block condensate generated by cooling of atmospheric air, for example, from entering the ductwork 68. The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence 52 is higher than the set point on the thermostat, or the set point plus a small amount, the residential heating and cooling system 50 may become operative to refrigerate additional air for circulation through the residence 52. When the temperature reaches the set point, or the set point minus a small amount, the residential heating and cooling system 50 may stop the refrigeration cycle temporarily.

[0039] 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 working fluid 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 working fluid.

[0040] In some embodiments, the indoor unit 56 may include a furnace system 70. For example, the indoor unit 56 may include the furnace system 70 when the residential heating and cooling system 50 is not configured to operate as a heat pump. The furnace system 70 may include a burner assembly and heat exchanger, among other components, inside the indoor unit 56. Fuel is provided to the burner assembly of the furnace 70 where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger 62, such that air directed by the blower 66 passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system 70 to the ductwork 68 for heating the residence 52.

[0041] FIG. 4 is an embodiment of a vapor compression system 72 that can be used in any of the systems described above and incorporates one or more drainage system in accordance with present embodiments. The vapor compression system 72 may circulate a working fluid 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.

[0042] 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.

[0043] The compressor 74 compresses a working fluid 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 working fluid 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 working fluid vapor may condense to a working fluid liquid in the condenser 76 as a result of thermal heat transfer with the environmental air 96. The liquid working fluid from the condenser 76 may flow through the expansion device 78 to the evaporator 80.

[0044] The liquid working fluid 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 working fluid in the evaporator 80 may undergo a phase change from the liquid working fluid to a working fluid vapor. In this manner, the evaporator 80 may reduce the temperature of the supply air stream 98 via thermal heat transfer with the working fluid. Thereafter, the vapor working fluid exits the evaporator 80 and returns to the compressor 74 by a suction line to complete the cycle.

[0045] 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.

[0046] 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.

[0047] While various features described in detail below with reference to later drawings may be discussed in the context of a single package HVAC unit, it should be understood that the same or similar features may be implemented in any of the HVAC systems or units described above with respect to FIGS. 1-4. As an example, a single package HVAC unit may include a front coil block-off (FCBO) box configured to isolate an interior of the FCBO box, which may be referred to as an additional section (e.g., having a portion of a heat exchanger, such as an end of an indoor coil, extending therein) of the single package HVAC unit, from a compressor section of the single package HVAC unit and / or an ambient environment. In this way, aluminum components in the interior of the FCBO box (e.g., the additional section) are fluidly isolated from copper components in the compressor section and / or from the ambient environment. In this way, fluid migration between the aluminum components and the copper components is reduced or negated, thereby reducing or negating corrosion (e.g., galvanic corrosion) that may otherwise occur in traditional configurations. In certain embodiments, copper components may also reside in the interior of the FCBO box and may be encased or covered by protective coverings, such as a sleeve (e.g., a polypropylene sleeve), a heat shrink wrap, or the like. Additionally or alternatively, in certain embodiments, aluminum components may also reside in the compressor section and may be encased or covered by protective coverings, such as a sleeve (e.g., a polypropylene sleeve), a heat shrink wrap, or the like. Additionally or alternatively, one or more brazed joints of the single package HVAC unit, such as a brazed join disposed in the compressor section between an aluminum portion and a copper portion of a header, may be encased or covered by protective coverings, such as a sleeve (e.g., a polypropylene sleeve), a heat shrink wrap, or the like. These and other aspects of the present disclosure are described in detail below with reference to later drawings.

[0048] With the preceding in mind, FIG. 5 is a schematic block diagram of an embodiment of an HVAC unit, such as a single package HVAC unit 100 (e.g., single package residential HVAC unit), including a front coil block-off (FCBO) box 102 configured to isolate certain components of the single package HVAC unit 100 from a compressor section 104 of the single package HVAC unit 100 and / or from an ambient environment 105. While the following discussion refers to the single package HVAC unit 100, it should be understood that presently disclosed embodiments may encompass other types of HVAC units in accordance with the present disclosure, such as any suitable embodiment described above with respect to FIGS. 1-4. Further, it should be noted that the single package HVAC unit 100 and associated componentry illustrated in FIG. 5 is exemplary and not representative of all embodiments of the present disclosure. For example, certain embodiments of the single package HVAC unit 100 may include additional componentry not illustrated in FIG. 5, and certain componentry of the single package HVAC unit 100 illustrated in FIG. 5 may be excluded in certain other embodiments.

[0049] As shown in the embodiment illustrated in FIG. 5, the FCBO box 102 isolates at least a portion of an indoor coil 106, such as an end portion of the indoor coil 106 having tubing impinging an end sheet of the indoor coil 106, from the compressor section 104. That is, the end portion of the indoor coil 106 may extend into an interior 107 of the FCBO box 102, the interior 107 also being referred to as an additional section 117 of the single package HVAC unit 100. For example, the tubing of the indoor coil 106 may include aluminum isolated (e.g., fluidly isolated) in the interior 107 of the FCBO box 102 from the compressor section 104. Further, the FCBO box 102 may isolate (e.g., fluidly isolate) one or more additional aluminum components 108 (e.g., one or more refrigerant distributors, one or more refrigerant headers, one or more valves, etc.) or portions thereof from the compressor section 104. In some embodiments, one or more copper components 110 (e.g., one or more equalizer lines, one or more liquid lines, one or more valves, etc.) or portions thereof reside within or otherwise extend into the interior 107 of the FCBO box 102, as shown. The one or more copper components 110 (or portions thereof) in the interior 107 of the FCBO box 102 may be isolated from the indoor coil 106 and / or the one or more additional aluminum components 108 in the FCBO box 102 via one or more protective coverings 112, such as one or more heat shrinks, one or more sleeves (e.g., polypropylene sleeve), etc.

[0050] The compressor section 104 includes a compressor 114 and one or more copper components 116 (e.g., one or more high pressure refrigerant lines coupled to the compressor 114, one or more low pressure refrigerant lines coupled to the compressor 114, etc.) disposed therein. As previously described, the FCBO box 102 is configured to isolate (e.g., fluidly isolate) componentry in the interior 107 of the FCBO box 102 from the ambient environment 105 and from the compressor 114 and the one or more copper components 116 in the compressor section 104. In this way, the FCBO box 102 protects the single package HVAC unit 100 from fluid migration between componentry in the FCBO box 102 (e.g., the indoor coil 106 and / or the one or more aluminum components 108) and componentry in the compressor section 104 (e.g., the compressor 114 and / or the one or more copper components 116), thereby reducing, negating, mitigating, or blocking contamination and / or corrosion (e.g., galvanic corrosion). The compressor section 104 in the illustrated embodiment also includes one or more aluminum components 118 (e.g., a capillary tube, a refrigerant header, etc.) or portions thereof residing or otherwise extending therein. The one or more aluminum components 118 (or portions thereof) in the compressor section 104 may be isolated from the compressor 114 and / or the one or more copper components 116 in the compressor section 104 via one or more protective coverings 120, such as one or more heat shrinks, one or more sleeves (e.g., polymere sleeves, in particular polypropylene sleeve), etc. Additionally or alternatively, a brazed joint between an aluminum portion of a component and a copper portion of the component, such as an aluminum portion of a header and a copper portion of the header, may be protected by one or more protective coverings.

[0051] FIG. 6 is a perspective view of an embodiment of the single package HVAC unit 100 of FIG. 5. In the illustrate embodiment, the single package HVAC unit 100 includes a condenser section 130 (condenser coil not shown) disposed at a top of the single package HVAC unit 100 relative to a Gravity vector 132 (e.g., when the single package HVAC unit 100 is in an upright and / or installed configuration). A housing 134 (or portion thereof) of the single package HVAC unit 100 is disposed below the condenser section 130, where the housing 134 defines a housing interior in which various componentry of the single package HVAC unit 100 is disposed. One or more panels of the housing 134 may form a part of (or otherwise be coupled to) the FCBO box 102 described above with respect to FIG. 5, may form a part of the compressor section 104 described above with respect to FIG. 5, or both.

[0052] For example, a first panel portion 136 may form a part of the FCBO box 102 and / or a second panel portion 138 may form a part of the compressor section 104. The first panel portion 136 and the second panel portion 138 may be discrete from one another (e.g., separate panels) in certain embodiments or integral with one another (e.g., a single panel) in certain other embodiments. In some embodiments, the first panel portion 136 and the second panel portion 138 may form at least a part of an integral panel, such as an L-shaped access panel 137 (e.g., compressor access panel) including an additional panel portion 139 extending from the second panel portion 138, enabling access to the compressor section 104 and / or the interior 107 of the FCBO box 102 described above with respect to FIG. 5. In some embodiments, a third panel portion 140 (e.g., a blower access panel) of the housing 134, which may be separate from the L-shaped access panel 137, may form a portion of the FCBO box 102 and / or may couple to a portion of the FCBO box 102. As shown, a groove 141 (also referred to as a notch or cut-out) in the first panel portion 136 may expose an opening 142 (e.g., a drain pan hole) through a portion of a component within the housing interior defined by the housing 134. For example, the component may be a drain pan forming a portion (or otherwise disposed in) in the FCBO box 102, and the opening 142 may correspond to a drain pan opening configured to enable a draining of condensate collected in the drain pan.

[0053] FIG. 7 is a perspective view of an embodiment of the single package HVAC unit 100 of FIG. 5, where the third panel portion 140 illustrated in FIG. 6 is removed to illustrate various portions of the FCBO box 102 beneath the third panel portion 140. For example, a bracket 150 (also referred to as an FCBO front cover) of the FCBO box 102 and an L-shaped FCBO panel 152 of the FCBO box 102 are illustrated in FIG. 7. The bracket 150 includes a ridge 154 configured to be coupled to the third panel portion 140 illustrated in FIG. 6 (e.g., via fasteners 156). Further, a portion of a drain pan 158 (also referred to as a drip pan), which may form a portion of the FCBO box 102, is illustrated in FIG. 7. In some embodiments, the bracket 150, the L-shaped FCBO panel 152, or both are coupled to the drain pan 158. For example, the bracket 150 may be coupled to the drain pan 158 via one or more fasteners 160, as shown. As previously described, the groove 141 in the first panel portion 136 of the housing 134 of the single package HVAC unit 100 may enable a draining of condensate collected in the drain pan 158 to an external environment (e.g., the ambient environment 105) via, for example, the opening 142. As previously described, the first panel portion 136 may, in some embodiments, define a portion of the FCBO box 102 and / or may be coupled to the FCBO box 102. The bracket 150, the L-shaped FCBO panel 152, and the drain pan 158 will be described in greater detail with reference to the drawings.

[0054] FIG. 8 is a perspective view of an embodiment of the single package HVAC unit 100 of FIG. 5 with the first panel portion 136, the second panel portion 138, and the additional panel portion 139 (e.g., forming an L-shaped panel as previously described) removed, along with the third panel portion 140 removed, to illustrate componentry inside of the housing 134. As previously described, the FCBO box 102 includes the bracket 150, the L-shaped FCBO panel 152, and the drain pan 158, among other componentry. In some embodiments, a gasket 159 may be disposed around and / or form a part of the drain pan 158. The FCBO box 102 also includes a compressor barrier block-off wall 170, where the compressor barrier block-off wall 170 and a first leg 172 of the L-shaped FCBO panel 152 (second leg hidden in FIG. 8) are disposed on opposing sides of the FCBO box 102. The compressor barrier block-off wall 170 extends between the interior 107 of the FCBO box 102 (e.g., the additional section of the single package HVAC unit 100) and the compressor section 104 of the single package HVAC unit 100. As shown in FIG. 8 and better illustrated in other drawings of the present disclosure, the compressor barrier block-off wall 170 may include sheet metal 174, and a gasket 176 (e.g., insulating gasket, gasket, insulator, etc.) may be disposed over or on the sheet metal 174.

[0055] The compressor barrier block-off wall 170, including the sheet metal 174 and the gasket 176 disposed over or on the sheet metal 174, fluidly isolate (e.g., along with other componentry) the interior 107 of the FCBO box 102 from the compressor section 104 of the single package HVAC unit 100. In certain embodiments, the compressor barrier block-off wall 170 may be coupled to an additional wall 177 having a curvature and extending away from the compressor barrier block-off wall 170 behind the compressor section 104, where the additional wall 177 at least partially defines the compressor section 104. The additional wall 177 will be better illustrated in later drawings of the present disclosure. The gasket 176, an additional gasket (e.g., additional insulating gasket, gasket, insulator, etc.), or both may seal an interface between the compressor barrier block-off wall 170 and the additional wall 177 in accordance with the present disclosure.

[0056] In some embodiments, the compressor barrier block-off wall 170 includes at least one cut-out (e.g., groove, notch) configured to receive conduits (e.g., tubing, headers, etc.) that pass between the interior 107 of the FCBO box 102 and the compressor section 104. For example, the compressor barrier block-off wall 170 in FIG. 8 includes a first cut-out 180 through which, for example, a header 182 extends and a second cut-out through 184 which, for example, an equalizer line 186 extends. A first grommet 188 (e.g., a first push-on or slide-on grommet) may seal the first cut-out 180 about the header 182, and a second grommet 190 (e.g., a second push-on or slide-on grommet) may seal the second cut-out 184 about the equalizer line 186. It should be noted that the portion of the header 182 disposed in the interior 107 of the FCBO box 102 may correspond to the one or more aluminum components 108 illustrated in FIG. 5. In some embodiments, the header 182 may include a brazed joint 191 between an aluminum portion of the header 182 and a copper portion of the header 182, where the brazed joint 191 is covered or encased by a protective covering 192, as shown. The protective covering 192 may prevent liquid migration between the aluminum and copper portions of the header 182, thereby reducing or negating corrosion that may otherwise be caused by liquid migration between the dissimilar metals. As shown, the brazed joint 191 is disposed in the compressor section 104 of the single package HVAC unit 100, although the brazed joint 191 and / or other brazed joints may be disposed in the interior 107 of the FCBO box 102 in certain embodiments.

[0057] Further, the portion of the equalizer line 186 disposed in the interior 107 of the FCBO box 102 and described above may correspond to the one or more copper components 110 illustrated in FIG. 5 and may be, in some embodiments, covered or encased by the one or more protective coverings 112 illustrated in FIG. 5. As shown, tubing 194 (e.g., coils, tubes, etc.) of a heat exchanger 196 of the single package HVAC unit 100 may extend into the interior 107 of the FCBO box 102 through, for example, an end sheet (mostly hidden from view in FIG. 8) of the heat exchanger 196, where the end sheet is a part of the FCBO box 102 in certain embodiments. A fin-and-tube portion of the heat exchanger 196 is shown schematically in FIG. 8 (e.g., extending below the FCBO box 102). FIG. 9 is a perspective view of an embodiment of the single package HVAC unit 100 of FIG. 5 with multiple panel portions (e.g., panel portions 136, 138, 139, 140) of the housing 134 removed and multiple portions of the FCBO box 102 (e.g., the bracket 150 and the L-shaped FCBO panel 152) removed to illustrate componentry inside of the housing 134. For example, as shown in FIG. 9, the heat exchanger 196 includes an end sheet 200, which may form a portion of the FCBO box 102, impinged by the tubing 194 of the heat exchanger 196, where the tubing 194 extends into the interior 107 defined by the FCBO box 102. Other aspects described above with respect to FIGS. 5-8 are also illustrated in FIG. 9, including the additional wall 177 configured to be coupled to the compressor barrier block-off wall 170.

[0058] FIGS. 10 and 11 are partially disassembled perspective views of an embodiment of the single package HVAC unit 100 of FIG. 5 illustrating the compressor barrier block-off wall 170 and the additional wall 177 configured to be coupled to (e.g., mounted to) the compressor barrier block-off wall 170. The drain pan 158 is also illustrated in FIGS. 10 and 11. In some embodiments, the compressor barrier block-off wall 170 is coupled to both the additional wall 177 and the drain pan 158, as shown via arrows in FIG. 10. Also shown in FIG. 10 are gaskets 210 (e.g., insulating gasket, gaskets, insulators, etc.) that may be disposed on edges of the compressor barrier block-off wall 170 and the additional wall 177. As shown in FIG. 11, the gasket 176 described above with reference to earlier drawings may be disposed on or over the sheet metal 174 of the compressor barrier block-off wall 170. An additional gasket 212, in some embodiments, may be disposed on or over sheet metal 214 of the additional wall 177. The gasket(s) 176, 210, 212 may coordinate to seal the interior of the FCBO box 102 from the compressor section 104, as previously described. For example, some or all of the gaskets 176, 210, 212, and / or any additional gaskets associated with the single package HVAC unit 100, may include rubber or another compliant material configured to generate one or more air seal(s) to fluidly isolate the interior 107 of the FCBO box 102 from the compressor section 104 and / or the ambient environment.

[0059] FIG. 12 is a partially disassembled perspective view of an embodiment of the single package HVAC unit 100 of FIG. 5, illustrating the L-shaped FCBO panel 152 of the FCBO box 102 and a thermostatic expansion valve (TXV) 220 disposed in a space at least partially defined by the L-shaped FCBO panel. For example, as previously described, the L-shaped FCBO panel 152 includes the first leg 172 and a second leg 222 (illustrated in FIG. 12) extending from (and at an angle to, such as a substantially 90-degree angle to) the first leg 172. Although not shown in the illustrated embodiment, the bracket 150 shown in FIGS. 7 and 8 may extend over the L-shaped FCBO panel 152, such that a space 224 within the interior 107 of the FCBO box 102 is defined between the bracket 150 and the L-shaped FCBO panel 152. The thermostatic expansion valve 220, from which the equalizer line 186 extends, is disposed in the space 224, as shown. Although not shown in the illustrated embodiment, a distributor coupled to the thermostatic expansion valve 220 also resides within the space 224. In some embodiments, the thermostatic expansion valve 220 includes a brass material and the distributor includes an aluminum material.

[0060] FIG. 13 is a perspective cross-sectional view of an embodiment of the single package HVAC unit 100, illustrating the spatial relationship between the compressor section 104 and the additional section 107. As shown, the compressor section 104 comprises a compressor 114 and a first set of tubes 300, corresponding to the one or more copper components 116, which are configured to convey a fluid of the HVAC system. The first set of tubes 300 comprises multiple copper tubes 302. The additional section 107, which corresponds to an interior of the FCBO box 102, is shown to contain a second set of tubes 304, which may correspond to the aluminum tubes 306 of the heat exchanger 196 and the aluminum tubes 308 connected to the thermostatic expansion valve 220.

[0061] The view illustrates the compressor barrier block-off wall 170 extending between the compressor section 104 and the additional section 107. This wall 170, along with other componentry of the FCBO box 102 (not fully shown), serves to fluidly isolate the additional section 107 from the compressor section 104. As depicted in this embodiment, a substantial majority of the first set of tubes 300 resides within the compressor section 104, while a substantial majority of the second set of tubes 304 resides within the additional section 107. This arrangement mitigates the migration of condensate and other liquids between the dissimilar metals of the first and second tube sets, thereby reducing the potential for galvanic corrosion.

[0062] Further, FIG. 13 illustrates an arrangement, wherein substantially every copper tube 302 is at least partially, if not fully, located within the compressor section 104. Conversely, substantially every aluminum tube 306, 308 is at least partially, if not fully, located within the additional section 117. The thermostatic expansion valve 220 is strategically positioned within the additional section 117, adjacent to the front coil of the heat exchanger 196 it regulates. Its placement is on the opposing side of the compressor barrier block-off wall 170 relative to the compressor 114, ensuring that this component, which may include dissimilar metals like brass, is also fluidly isolated from the main copper componentry in the compressor section 104. This specific placement and the high degree of separation—exceeding 90%-maximizes the isolation between the dissimilar materials, thereby providing robust protection against galvanic corrosion.

[0063] While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the 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 (i.e., those unrelated to the presently contemplated best mode of carrying out the disclosure, or those unrelated to enabling the claimed disclosure). 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.

Claims

1. A heating, ventilation and air conditioning (HVAC) system, comprising:a compressor section corresponding to a compressor;an additional section corresponding to at least an end portion of a heat exchanger;a compressor barrier block-off wall extending between and at least partially separating the compressor section and the additional section configured to at least partially isolate the additional section from the compressor section;a tube network in connection with the compressor and the heat exchanger, wherein the tube network comprises at least a first set of tubes made from a first material and a second set of tubes made from a second material, wherein the first material is different from the second material and the majority of the first set of tubes is positioned in the compressor section and the majority of the second set of tubes is located in the additional section.

2. The HVAC system of claim 1, wherein the first material comprises copper and the second material comprises aluminum.

3. The HVAC system of claim 1, wherein at least 90% of the first set of tubes is located in the compressor section and at least 90% of the second set of tubes is located in the additional section.

4. The HVAC system of claim 1, wherein at least 100% of the first set of tubes is located in the compressor section and at least 100% of the second set of tubes is located in the additional section.

5. The HVAC system of claim 1, comprising:a front coil block-off (FCBO) box configured to at least partially isolate the additional section from the compressor section, the additional section from an ambient environment, or both, wherein the compressor barrier block-off wall limits the front coil block-off box at least on one side.

6. The HVAC system of claim 1, wherein the compressor barrier block-off wall comprises at least one sheet metal piece.

7. The HVAC system of claim 1, wherein the compressor barrier block-off wall comprises a gasket disposed on or over the at least one sheet metal piece.

8. The HVAC system of claim 1, wherein the compressor barrier block-off wall comprises a cut-out, the HVAC system comprises a header configured to convey a fluid between the compressor section and the additional section, and the header extends through the cut-out between the additional section and the compressor section.

9. The HVAC system of claim 8, comprising a push-on or slide-on grommet configured to seal the cut-out about the header.

10. The HVAC system of claim 1, comprising a thermostatic expansion valve (TXV) and a distributor disposed in the space.

11. The HVAC system of claim 10, wherein the compressor barrier block-off wall comprises a cut-out, the HVAC system comprises an equalizer line extending from the thermostatic expansion valve (TXV) disposed in the additional section, and the equalizer line extends through the cut-out between the additional section and the compressor section.

12. The HVAC system of claim 11, comprising a push-on or slide-on grommet configured to seal the cut-out about the equalizer line.

13. The HVAC system of claim 5, wherein the FCBO box comprises an L-shaped FCBO panel having a first leg and a second leg disposed at an angle with respect to the first leg, wherein the first leg and the compressor barrier block-off wall are positioned on opposing sides of the FCBO box, and wherein the second leg extends from the first leg toward the compressor barrier block-off wall.

14. The HVAC system of claim 13, wherein the FCBO box comprises a drain pan extending between the compressor barrier block-off wall and the L-shaped FCBO panel, and the drain pan is configured to collect condensate gravity fed toward and into the drain pan.

15. The HVAC system of claim 14, wherein the L-shaped FCBO panel is sloped with respect to the drain pan and configured to channel condensate into the drain pan.

16. The HVAC system of claim 14, wherein the FCBO box comprises a bracket extending over the L-shaped FCBO panel such that a space is defined between the second leg of the L-shaped FCBO panel and the bracket, and the bracket is anchored to the drain pan, a drain pan stopper, or both.

17. The HVAC system of claim 16, wherein the FCBO box comprises an end sheet of the heat exchanger, the end sheet is impinged by one or more tubes of the end portion of the heat exchanger, and the end sheet and the bracket are disposed on opposing ends of the FCBO box.

18. The HVAC system of claim 16, wherein the FCBO box comprises a portion of an L-shaped access panel anchored to or disposed adjacent to another access panel anchored to the bracket and comprising a gasket disposed on or over the L-shaped access panel.

19. A heating, ventilation, and air conditioning (HVAC) system, comprising:a compressor section corresponding to a compressor;an additional section corresponding to at least an end portion of a heat exchanger;a compressor barrier block-off wall extending between and at least partially separating the compressor section and the additional section configured to fluidly isolate the additional section from the compressor section; anda thermostatic expansion valve within the additional section configured to control refrigerant flow;wherein the thermostatic expansion valve has a greater distance from the compressor barrier block-off wall than the end portion of the heat exchanger.

20. A heating, ventilation, and air conditioning (HVAC) system, comprising:a compressor fluidly connected to a first set of tubes being of a first material;a heat exchanger having an indoor coil and a second set of tubes being of a second material and in fluid connection to the first set of tubes, wherein the second material is different to the first material; anda compressor barrier block-off wall disposed between the compressor and the heat exchanger, wherein the first set of tubes is positioned on the compressor side of the compressor barrier block-off wall and the second set of tubes is positioned on the heat exchanger side of the compressor barrier block-off wall.

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