MOVABLE HEAT EXCHANGER

Abstract

A heating, ventilating, and air conditioning (HVAC) system includes a heat exchanger configured to translate between a first position within an air flow path of the HVAC system and a second position external to the air flow path of the HVAC system.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 62/517,739, entitled “CONFORMING GAS HEAT EXCHANGER,” filed Jun. 9, 2017, which is hereby incorporated by reference in its entirety for all purposes.

BACKGROUND

The present disclosure relates generally to heating, ventilating, and air conditioning (HVAC) systems, and specifically, to a heat exchanger system for HVAC systems.

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

Environmental control systems are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. The environmental control system may control the environmental properties through control of an air flow delivered to and ventilated from the environment. For example, a heating, ventilating, and air conditioning (HVAC) system may use heat exchangers to change the temperature of air flowing through the HVAC system. The HVAC system may be used to increase the temperature of the air flow to heat a home, office, hospital, or any other building. As such, the HVAC system may use a heat exchanger that heats the air flow during a heating mode of the HVAC system. In some cases, during a cooling mode of the HVAC system, the air must still flow through the heat exchanger, regardless of whether the heat exchanger is in operation during the cooling mode.

SUMMARY

A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

In one embodiment, a heating, ventilating, and air conditioning (HVAC) system includes a heat exchanger configured to translate between a first position within an air flow path of the HVAC system and a second position external to the air flow path of the HVAC system.

In one embodiment, a method of operating a heating, ventilating, and air conditioning (HVAC) system includes operating the HVAC system in a first mode with a heat exchanger disposed within an air flow path and operating the HVAC system in a second mode with the heat exchanger positioned external to the air flow path.

In one embodiment, a packaged heating, ventilating, and air conditioning (HVAC) unit, includes a heat source disposed within a first volume of a housing of the packaged HVAC unit, and a heat exchanger disposed within a second volume of the housing of the packaged HVAC unit. The heat exchanger is configured to establish a heat exchange relationship with an air flow within the housing in a heating mode of the packaged HVAC unit and the heat exchanger is configured to translate from within the second volume to a position external to the second volume in a cooling mode of the packaged HVAC unit.

BRIEF DESCRIPTION OF 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 schematic of an environmental control for building environmental management that may employ one or more HVAC units, in accordance with an aspect of the present disclosure;

FIG. 2 is a perspective view of an embodiment of a HVAC unit that may be used in the environmental control system of FIG. 1, in accordance with an aspect of the present disclosure;

FIG. 3 is a schematic of a residential heating and cooling system, in accordance with an aspect of the present disclosure;

FIG. 4 is a schematic of an embodiment of a vapor compression system that can be used in any of the systems of FIGS. 1-3, in accordance with an aspect of the present disclosure;

FIG. 5 is a perspective view of an embodiment of a HVAC unit, in accordance with an aspect of the present disclosure;

FIG. 6 is a perspective view of the embodiment of the HVAC unit of FIG. 5 in an additional configuration, in accordance with an aspect of the present disclosure;

FIG. 7 is a perspective view of an embodiment of a HVAC unit, in accordance with an aspect of the present disclosure;

FIG. 8 is a perspective view of the embodiment of the HVAC unit of FIG. 7 in an additional configuration, in accordance with an aspect of the present disclosure;

FIG. 9 is a perspective view of an embodiment of a HVAC unit, in accordance with an aspect of the present disclosure;

FIG. 10 is a perspective view of the embodiment of the HVAC unit of FIG. 9 in an additional configuration, in accordance with an aspect of the present disclosure;

FIG. 11 is a perspective view of an embodiment of a HVAC unit using a protection system, in accordance with an aspect of the present disclosure;

FIG. 12 is a perspective view of the embodiment of the HVAC unit of FIG. 11 in an additional configuration, in accordance with an aspect of the present disclosure;

FIG. 13 is a perspective view of an embodiment of a HVAC unit using a protection system, in accordance with an aspect of the present disclosure;

FIG. 14 is a perspective view of the embodiment of the HVAC unit of FIG. 13 in an additional configuration, in accordance with an aspect of the present disclosure;

FIG. 15 is a perspective view of an embodiment of a HVAC unit using a protection system, in accordance with an aspect of the present disclosure;

FIG. 16 is a perspective view of the embodiment of the HVAC unit of FIG. 15 in an additional configuration, in accordance with an aspect of the present disclosure; and

FIG. 17 is a block diagram of an embodiment of a process to change operating modes of a HVAC unit that can be used in any of the systems in FIGS. 5-16, 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 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.

The present disclosure is directed to heating, ventilating, and air conditioning (HVAC) systems that use a heat exchanger for increasing the temperature in air flowing through the HVAC system. In some embodiments, the heat exchanger may be disposed in a packaged unit capable of both heating and cooling an air flow, such as a supply air flow. As an example, the heat exchanger may be located along an air flow path of the HVAC system and thus, the air flow may flow through or across the heat exchanger. The heat exchanger may transfer heat to the air flow to increase the temperature of the air flow before it is supplied to a conditioned space. The air flow may then be circulated, such as via ductwork, to heat different areas of a building conditioned by the HVAC system. To circulate the air flow, the HVAC system may use a blower that increases the velocity of the air flow. The heat exchanger may create a resistance in the air flow path that decreases the velocity of the air flow, and thus the blower may be located upstream of the heat exchanger to compensate and increase the velocity of the air flow prior to flowing across the heat exchanger. As a result, the air flow may flow across the heat exchanger and exit the HVAC system at a desired velocity.

Generally, the heat exchanger may operate during a heating mode in the HVAC system to increase the temperature of the air flow. For example, during the heating mode, the heat exchanger may contain a heated fluid, such as a combusted gas, that transfers heat to the air flow as the air flow passes across the heat exchanger. However, in some cases, such as during a cooling mode in the HVAC system, the heat exchanger may not be in operation so as to not increase the temperature of the air flow. For example, the heat exchanger may not contain the heated fluid when the HVAC system operates in the cooling mode. Therefore, the temperature of the air flow may remain substantially the same before and after passing across the heat exchanger. Since the heat exchanger may remain in the air flow path of the HVAC system during the cooling mode, the heat exchanger may still be a source of a resistance in the air flow.

In accordance with certain embodiments of the present disclosure, it is now recognized that removing the heat exchanger from the air flow path when the heat exchanger is not operated to condition the air flow may decrease the hydraulic resistance in the HVAC system. That is, it is presently recognized that removing the heat exchanger from the air flow path when not in use may reduce an undesired decrease in velocity of the air flow and/or reduce a pressure drop in the air flow. As such, the blower may operate at a lower level, thereby enabling energy or operational cost savings.

Removing the heat exchanger from the air flow path may be accomplished in various ways, as described below. As an example, the blower and the heat exchanger may be disposed in a section within the HVAC system or unit. Within the section, the heat exchanger may be located in an area between the blower and an opening leading to the ductwork or building conditioned by the HVAC system, such that air exiting the blower is directed across the heat exchanger and toward the opening. When the HVAC system switches from the heating mode to the cooling mode, the heat exchanger may be moved, such that air exiting the blower flows directly into the opening. In other words, when the heat exchanger is moved, the heat exchanger is not in the air flow path between the blower and the opening of the building or ductwork. Conversely, when the HVAC system switches from the cooling mode to the heating mode, the heat exchanger may return to its original position within the section so that air may flow across the heat exchanger to increase in temperature in the heating mode before the air is supplied to the building or ductwork.

The heat exchanger system may be used in association with any number of HVAC systems, including those in residential and commercial settings. For example, the heat exchanger system may be utilized in a rooftop unit (RTU), a dedicated outdoor air system, or a split system. Non-limiting examples of systems that may use the heat exchanger system of the present disclosure are described herein with respect to FIGS. 1-4.

Turning now to the drawings, FIG. 1 illustrates a heating, ventilating, and air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units. 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 packaged unit containing other equipment, such as a blower, integrated air handler, and/or auxiliary heating unit. In other embodiments, the HVAC unit 12 may be part of a split HVAC system, such as the system shown in FIG. 3, which includes an outdoor HVAC unit 58 and an indoor HVAC unit 56.

The HVAC unit 12 is an air cooled device that implements a refrigeration cycle to provide conditioned air to the building 10. Specifically, the HVAC unit 12 may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow is supplied to the building. In the illustrated embodiment, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow from the building 10. After the HVAC unit 12 conditions the air, the air is supplied to the building 10 via ductwork 14 extending throughout the building 10 from the HVAC unit 12. For example, the ductwork 14 may extend to various individual floors or other sections of the building 10. In certain embodiments, the HVAC unit 12 may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other embodiments, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream.

A control device 16, one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device 16 also may be used to control the flow of air through the ductwork 14. For example, the control device 16 may be used to regulate operation of one or more components of the HVAC unit 12 or other components, such as dampers and fans, within the building 10 that may control flow of air through and/or from the ductwork 14. In some embodiments, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the supply air, return air, and so forth. Moreover, the control device 16 may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building 10.

FIG. 2 is a perspective view of an embodiment of the HVAC unit 12. In the illustrated embodiment, the HVAC unit 12 is a single package unit that may include one or more independent refrigeration circuits and components that are tested, charged, wired, piped, and ready for installation. The HVAC unit 12 may provide a variety of heating and/or cooling functions, such as cooling only, heating only, cooling with electric heat, cooling with dehumidification, cooling with gas heat, or cooling with a heat pump. As described above, the HVAC unit 12 may directly cool and/or heat an air stream provided to the building 10 to condition a space in the building 10.

As shown in the illustrated embodiment of FIG. 2, a cabinet 24 encloses the HVAC unit 12 and provides structural support and protection to the internal components from environmental and other contaminants. In some embodiments, the cabinet 24 may be constructed of galvanized steel and insulated with aluminum foil faced insulation. Rails 26 may be joined to the bottom perimeter of the cabinet 24 and provide a foundation for the HVAC unit 12. In certain embodiments, the rails 26 may provide access for a forklift and/or overhead rigging to facilitate installation and/or removal of the HVAC unit 12. In some embodiments, the rails 26 may fit into “curbs” on the roof to enable the HVAC unit 12 to provide air to the ductwork 14 from the bottom of the HVAC unit 12 while blocking elements such as rain from leaking into the building 10.

The HVAC unit 12 includes heat exchangers 28 and 30 in fluid communication with one or more refrigeration circuits. Tubes within the heat exchangers 28 and 30 may circulate refrigerant, such as R-410A, through the heat exchangers 28 and 30. The tubes may be of various types, such as multichannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers 28 and 30 may implement a thermal cycle in which the refrigerant undergoes phase changes and/or temperature changes as it flows through the heat exchangers 28 and 30 to produce heated and/or cooled air. For example, the heat exchanger 28 may function as a condenser where heat is released from the refrigerant to ambient air, and the heat exchanger 30 may function as an evaporator where the refrigerant absorbs heat to cool an air stream. In other embodiments, the HVAC unit 12 may operate in a heat pump mode where the roles of the heat exchangers 28 and 30 may be reversed. That is, the heat exchanger 28 may function as an evaporator and the heat exchanger 30 may function as a condenser. In further embodiments, the HVAC unit 12 may include a furnace for heating the air stream that is supplied to the building 10. While the illustrated embodiment of FIG. 2 shows the HVAC unit 12 having two of the heat exchangers 28 and 30, in other embodiments, the HVAC unit 12 may include one heat exchanger or more than two heat exchangers.

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

The HVAC unit 12 also may include other equipment for implementing the thermal cycle. Compressors 42 increase the pressure and temperature of the refrigerant before the refrigerant enters the heat exchanger 28. The compressors 42 may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors 42 may include a pair of hermetic direct drive compressors arranged in a dual stage configuration 44. However, in other embodiments, any number of the compressors 42 may be provided to achieve various stages of heating and/or cooling. As may be appreciated, additional equipment and devices may be included in the HVAC unit 12, such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things.

The HVAC unit 12 may receive power through a terminal block 46. For example, a high voltage power source may be connected to the terminal block 46 to power the equipment. The operation of the HVAC unit 12 may be governed or regulated by a control board 48. The control board 48 may include control circuitry connected to a thermostat, sensors, and alarms. One or more of these components may be referred to herein separately or collectively as the control device 16. The control circuitry may be configured to control operation of the equipment, provide alarms, and monitor safety switches. Wiring 49 may connect the control board 48 and the terminal block 46 to the equipment of the HVAC unit 12.

FIG. 3 illustrates a residential heating and cooling system 50, also in accordance with present techniques. The residential heating and cooling system 50 may provide heated and cooled air to a residential structure, as well as provide outside air for ventilation and provide improved indoor air quality (IAQ) through devices such as ultraviolet lights and air filters. In the illustrated embodiment, the residential heating and cooling system 50 is a split HVAC system. In general, a residence 52 conditioned by a split HVAC system may include refrigerant conduits 54 that operatively couple the indoor unit 56 to the outdoor unit 58. The indoor unit 56 may be positioned in a utility room, an attic, a basement, and so forth. The outdoor unit 58 is typically situated adjacent to a side of residence 52 and is covered by a shroud to protect the system components and to prevent leaves and other debris or contaminants from entering the unit. The refrigerant conduits 54 transfer refrigerant between the indoor unit 56 and the outdoor unit 58, typically transferring primarily liquid refrigerant in one direction and primarily vaporized refrigerant in an opposite direction.

When the system shown in FIG. 3 is operating as an air conditioner, a heat exchanger 60 in the outdoor unit 58 serves as a condenser for re-condensing vaporized refrigerant flowing from the indoor unit 56 to the outdoor unit 58 via one of the refrigerant conduits 54. In these applications, a heat exchanger 62 of the indoor unit functions as an evaporator. Specifically, the heat exchanger 62 receives liquid refrigerant, which may be expanded by an expansion device, and evaporates the refrigerant before returning it to the outdoor unit 58.

The outdoor unit 58 draws environmental air through the heat exchanger 60 using a fan 64 and expels the air above the outdoor unit 58. When operating as an air conditioner, the air is heated by the heat exchanger 60 within the outdoor unit 58 and exits the unit at a temperature higher than it entered. The indoor unit 56 includes a blower or fan 66 that directs air through or across the indoor heat exchanger 62, where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork 68 that directs the air to the residence 52. The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence 52 is higher than the set point on the thermostat, or the set point plus a small amount, the residential heating and cooling system 50 may become operative to refrigerate additional air for circulation through the residence 52. When the temperature reaches the set point, or the set point minus a small amount, the residential heating and cooling system 50 may stop the refrigeration cycle temporarily.

The residential heating and cooling system 50 may also operate as a heat pump. When operating as a heat pump, the roles of heat exchangers 60 and 62 are reversed. That is, the heat exchanger 60 of the outdoor unit 58 will serve as an evaporator to evaporate refrigerant and thereby cool air entering the outdoor unit 58 as the air passes over the outdoor heat exchanger 60. The indoor heat exchanger 62 will receive a stream of air blown over it and will heat the air by condensing the refrigerant.

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

FIG. 4 is an embodiment of a vapor compression system 72 that can be used in any of the systems described above. The vapor compression system 72 may circulate a refrigerant through a circuit starting with a compressor 74. The circuit may also include a condenser 76, an expansion valve(s) or device(s) 78, and an evaporator 80. The vapor compression system 72 may further include a control panel 82 that has an analog to digital (A/D) converter 84, a microprocessor 86, a non-volatile memory 88, and/or an interface board 90. The control panel 82 and its components may function to regulate operation of the vapor compression system 72 based on feedback from an operator, from sensors of the vapor compression system 72 that detect operating conditions, and so forth.

In some embodiments, the vapor compression system 72 may use one or more of a variable speed drive (VSDs) 92, a motor 94, the compressor 74, the condenser 76, the expansion valve or device 78, and/or the evaporator 80. The motor 94 may drive the compressor 74 and may be powered by the variable speed drive (VSD) 92. The VSD 92 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 94. In other embodiments, the motor 94 may be powered directly from an AC or direct current (DC) power source. The motor 94 may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

The compressor 74 compresses a refrigerant vapor and delivers the vapor to the condenser 76 through a discharge passage. In some embodiments, the compressor 74 may be a centrifugal compressor. The refrigerant vapor delivered by the compressor 74 to the condenser 76 may transfer heat to a fluid passing across the condenser 76, such as ambient or environmental air 96. The refrigerant vapor may condense to a refrigerant liquid in the condenser 76 as a result of thermal heat transfer with the environmental air 96. The liquid refrigerant from the condenser 76 may flow through the expansion device 78 to the evaporator 80.

The liquid refrigerant delivered to the evaporator 80 may absorb heat from another air stream, such as a supply air stream 98 provided to the building 10 or the residence 52. For example, the supply air stream 98 may include ambient or environmental air, return air from a building, or a combination of the two. The liquid refrigerant in the evaporator 80 may undergo a phase change from the liquid refrigerant to a refrigerant vapor. In this manner, the evaporator 38 may reduce the temperature of the supply air stream 98 via thermal heat transfer with the refrigerant. Thereafter, the vapor refrigerant exits the evaporator 80 and returns to the compressor 74 by a suction line to complete the cycle.

In some embodiments, the vapor compression system 72 may further include a reheat coil in addition to the evaporator 80. For example, the reheat coil may be positioned downstream of the evaporator relative to the supply air stream 98 and may reheat the supply air stream 98 when the supply air stream 98 is overcooled to remove humidity from the supply air stream 98 before the supply air stream 98 is directed to the building 10 or the residence 52.

It should be appreciated that any of the features described herein may be incorporated with the HVAC unit 12, the residential heating and cooling system 50, or other HVAC systems. Additionally, while the features disclosed herein are described in the context of embodiments that directly heat and cool a supply air stream provided to a building or other load, embodiments of the present disclosure may be applicable to other HVAC systems as well. For example, the features described herein may be applied to mechanical cooling systems, free cooling systems, chiller systems, or other heat pump or refrigeration applications.

As noted above, air may flow through a HVAC system, where its temperature may be increased by a heat exchanger, such as via the furnace system 70 of FIG. 3, in a heating mode. As such, the heat exchanger may be disposed within an air flow path that the air flows through. Further, the heat exchanger may be coupled to a heat source, such as a burner that generates combustion products, to provide heat to air flowing through or across the heat exchanger. In accordance with present embodiments, the heat exchanger may be a part of a heat exchanger system within the HVAC system, where the heat exchanger system may remove the heat exchanger from the air flow path when the heat exchanger is not in operation. For example, the heat exchanger system may move the heat exchanger out of the air flow path when the HVAC system is in a cooling mode. During cooling mode, the heat exchanger may not be used for heating the air flow and thus, may not be in operation. In some embodiments, the heat exchanger system may include a mechanism to remove the heat exchanger from the air flow path while protecting the heat exchanger after the heat exchanger has been removed. The heat exchanger system may also re-position the heat exchanger within the air flow path during heating mode of the HVAC system when the heat exchanger is used for heating the air flow. Thus, the HVAC system changes the position of the heat exchanger to correspond with the mode of operation of the HVAC system. For purposes of discussion, the disclosure will refer to the heat exchanger as it may be utilized in a packaged unit, such as the HVAC unit 12 of FIGS. 1 and 2. However, the systems and concepts described below may be used in other types of HVAC systems, such as the residential heating and cooling system 50 of FIG. 3.

FIG. 5 is a perspective view an embodiment of a packaged unit 100 that may use the heat exchanger system mentioned above. In the illustrated embodiment, the packaged unit 100 includes multiple components enclosed within an internal volume of a housing 102 of the packaged unit 100. The packaged unit 100 may be configured to circulate air and therefore may include a return section 104 to take in air flow, such as a return air flow from building 10, and a supply section 106 to output air flow. As an example, the packaged unit 100 may be located in an outside environment, such as on a rooftop, and may be coupled to ductwork that leads to rooms or other areas within a building, such as building 10 of FIG. 1. The ductwork may couple to the return section 104 and the supply section 106. In this manner, the packaged unit 100 may circulate air in the building 10.

In addition to circulating air, the packaged unit 100 may change the temperature of the air flow. For example, the packaged unit 100 may include a refrigerant circuit that circulates a refrigerant therethrough, where the refrigerant circuit is in thermal communication with the air flow. The refrigerant may flow through a condenser 108, where the refrigerant may be cooled. FIG. 5 illustrates the condenser 108 as using a fan that may blow ambient air over the condenser 108 to remove heat from the refrigerant via convection, but in other embodiments, the condenser 108 may use another means of cooling the refrigerant, such as via a coolant. After being cooled, the refrigerant may then flow through an evaporator 110, where the refrigerant may interact with the air flow by receiving heat from the air flow. Thus, the refrigerant may be heated and the air flow may be cooled at the evaporator 110. After being heated at the evaporator 110, the refrigerant may return to the condenser 108 where it may once again be cooled.

The packaged unit 100 may be capable of operating in a heating mode and a cooling mode. During operation of the heating mode, air may be taken into the packaged unit 100 at the return section 104 to enter an air flow path. As mentioned, air may be taken in from ductwork that is connected to a building. However, in other embodiments, air may be taken in from ambient air, such as from an outside environment. In certain embodiments, the air flow passing through the packaged unit 100 may include air from the return section 104 and from ambient. After the air flow enters the packaged unit 100, the air flow may pass through a filter 112. The filter 112 may remove particles from the air flow, such as dirt and other debris. The filter 112 may be a pleated filter, an electrostatic filter, a HEPA filter, or a fiber glass filter that traps the debris when the air flow passes through the filter 112. After being filtered, the air flow may be directed to the evaporator 110. As discussed above, at the evaporator 110, the air flow may be cooled by transferring heat to the refrigerant within the evaporator 110. In addition, cooling the air flow may also remove moisture from the air flow and thus, the packaged unit 100 may also dehumidify the air flow. Once cooled, the air flow may be directed to a blower 114, which may increase the velocity of the air flow to exit the supply section 106 of the packaged unit 100 at a high enough velocity, such as to be circulated through the ductwork. In some embodiments, the blower 114 may also operate to draw air in through the return section 104 and thereby function to both draw in and expel air.

In some modes of operation, prior to exiting the packaged unit 100, the air may be heated by a heat exchanger 116. By way of example, the heat exchanger 116 may be coupled to a heat source, which is not shown in FIG. 5. The heat source may be coupled to the heat exchanger 116 at attachment coil segments 118. In some embodiments, the heat exchanger 116 may be a gas heat exchanger and may be coupled with a gas burner that combusts a gas, such as acetylene, natural gas, propane, another gas, or any combination thereof to flow into the heat exchanger 116 at an elevated temperature. When the air flow is directed across the heat exchanger 116, the air flow may absorb heat from the combusted gas, thereby increasing the temperature of the air flow. In some embodiments, there may be an additional heat exchanger that further heats the air flow to increase the heating efficiency of the packaged unit 100. Thereafter, the air flow may then exit the packaged unit 100 at a higher temperature compared to when the air flow entered the packaged unit 100.

To separate the components within the packaged unit 100, the packaged unit 100 may include partitions 120. As an example, the partitions 120 may divide the internal volume within the housing 102 into a first volume 122 that contains the heat source, a second volume 124 where the air flow may exit the packaged unit 100, a third volume 126 that contains the condenser 108, and a fourth volume 128 where air flow may enter the packaged unit 100.

As mentioned above, the packaged unit 100 may operate in a cooling mode. During the cooling mode, the heat exchanger 116 may not be operating to heat the air flow because the increase of temperature would not be desirable. Therefore, in present embodiments, the heat exchanger 116 may be moved so that the air flow, after being cooled in the evaporator 110, may be directed straight from the blower 114 to the supply section 106 to exit the packaged unit 100. That is, the heat exchanger 116 may be moved out of the second volume 124 such that the heat exchanger 116 is no longer in the air flow path between the blower 114 and the supply section 106. If the packaged unit 100 includes the additional heat exchanger, the additional heat exchanger may also be moved out of the second volume 124. In some embodiments, the additional heat exchanger may be moved out of the second volume 124 simultaneously when the heat exchanger 116 is moved out of the second volume 124. In this configuration, the air flow may directly exit the packaged unit 100 from the blower 114. As such, the blower 114 may operate at a lower power because the blower 114 may no longer compensate for velocity loss resulting from the resistance caused by the heat exchanger 116. For example, the blower 114 may include a fan coupled to a VSD fan motor. The VSD fan motor may rotate the fan at a lower speed in the cooling mode than in the heating mode and thus save energy costs to operate the VSD fan motor.

FIG. 6 is a perspective view of an embodiment of the packaged unit 100 operating in the cooling mode. As shown in FIG. 6, the heat exchanger 116 is part of a heat exchanger system 150 that may move or translate out of the second volume 124. The heat exchanger system 150 may include a translation mechanism 152 that enables the heat exchanger system 150 to be removed from the second volume 124, such as via sliding, rotating, another suitable movement, or any combination thereof. In some embodiments, the heat exchanger system 150 may move out of the second volume 124 in a direction 154, as illustrated in FIG. 6. For example, the translation mechanism 152 may include rails 156 to guide the heat exchanger system 150 in the direction 154. When the heat exchanger system 150 is moved out of the second volume 124, the air flow may bypass flowing across the heat exchanger 116 when exiting through the supply section 106. Furthermore, since moving the heat exchanger system 150 out of the second volume 124 may substantially remove the heat exchangers system 150 from the housing 102 of the packaged unit 100, the heat exchanger system 150 may include a protection system that covers the heat exchanger system 150 to block external elements, such as leaves or precipitation, from contacting the heat exchanger system 150. The position of the heat exchanger system 150 during the cooling mode may be considered an extended position, because the heat exchanger system 150 is extended out of the housing 102. Likewise, the position of the heat exchanger system 150 during the heating mode may be considered a retracted position, because heat exchanger system 150 is retracted within the housing 102.

To move the heat exchanger system 150 between the extended position shown in FIG. 6 and the retracted position shown in FIG. 5, the packaged unit 100 may include a controller 156 configured to adjust the position of the heat exchanger system 150 based on the operating mode of the packaged unit 100. For example, the controller 156 may receive a signal indicating a desired operation of the cooling mode, and, in response, the controller 156 may operate to move the heat exchanger system 150 to the extended position shown in FIG. 6. At a different time, the controller 156 may receive a signal indicating a desired operation of the heating mode, and, in response, the controller 156 may operate to move the heat exchanger system 150 back into the second volume 124 in the retracted position, such as that shown in FIG. 5. To facilitate movement of the heat exchanger system 150, the controller 156 may include a memory with stored instructions for controlling the heat exchanger system 150, and a processor configured to execute such instructions. For example, the processor may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or any combination thereof. Additionally, the memory may include volatile memory, such as random access memory (RAM), and/or non-volatile memory, such as read-only memory (ROM), optical drives, hard disc drives, or solid-state drives. Although FIG. 6 illustrates the controller 156 as being disposed within the packaged unit 100, in some embodiments, the controller 156 may be external to the packaged unit 100, such as attached to the outside of the housing 102, or the controller 156 may be located remotely relative to the packaged unit 100.

When the heat exchanger system 150 is in the extended position, the attachment coil segments 118 of the heat exchanger 116 may decouple from the heat source such that the heat source remains inside the packaged unit 100. As such, the heat source may be exposed to the second volume 124. To protect the heat source from the air flow, and vice versa, when the heat exchanger system 150 is in the extended position, the packaged unit 100 may include a plate system 158. The plate system 158 may be a part of the partitions 120 disposed in the packaged unit 100. When the heat exchanger system 150 is in the extended position, the plate system 158 may translate to cover the heat source, thereby blocking the air flow from traveling from the second volume 124 to the first volume 122.

FIGS. 7-10 illustrate embodiments of the plate system 158 to block air flow from the second volume 124 to the first volume 122 when the heat exchanger system 150 is in the extended position. FIG. 7 is a perspective view of a packaged unit 200 that includes a horizontal plate system 202. The horizontal plate system 202 may be disposed adjacent to a heat exchanger system 150 such that the horizontal plate system 202 moves with the heat exchanger system 150. That is, the horizontal plate system 202 may move along the direction 206 as the heat exchanger system 150 moves in and out of the packaged unit 200. The horizontal plate system 202 may include a first plate 208 that couples to the heat exchanger system 150. The first plate 208 may be located in a first volume 212 of the packaged unit 200 when the heat exchanger system 204 is in the retracted position within a second volume 214 of the packaged unit 200. The first plate 208 may be positioned in a manner as to not interfere with a connection between a heat source 216 and a heat exchanger of the heat exchanger system 150. In addition, the horizontal plate system 202 includes a second plate 218 coupled to the first plate 208 and is disposed in a third volume 220 of the packaged unit 200 when the heat exchanger system 150 is within the second volume 214. When the heat exchanger system 150 is in the retracted position, the second plate 218 may be in a first position, where the second plate 218 overlaps with the partition 222 that separates the third volume 220 from a fourth volume 224. When the heat exchanger system 150 is in the extended position, the second plate 218 may be in a second position, where the second plate 218 is located between the first volume 212 and the second volume 214 to block air flow from entering the first volume 212 from the second volume 214.

For example, FIG. 8 illustrates the packaged unit 200 when the heat exchanger system 150 is in the extended position. As discussed above, in the extended position, the heat source 216 may decouple from the heat exchanger 116, thereby exposing the heat source 216 and the first volume 212 to the second volume 214. As the heat exchanger system 150 extends, the second plate 218 translates to the second position to separate the first volume 212 from the second volume 214. In one embodiment, as a result of translating the heat exchanger system 150 out of the second volume 214 of the packaged unit 200, the second plate 218 slides in a direction 230. In this manner, the second plate 218 moves from the third volume 220 to the first volume 212. As an example, the first plate 208 may be coupled to the heat exchanger system 150, and the second plate 218 may be coupled to the first plate 208. In this manner, when the heat exchanger system 150 translates out of the second volume 214, the heat exchanger system 150 draws the first plate 208 out of the second volume 214 which further draws the second plate 218 to the second position discussed above. Coupling between the first plate 208 and the heat exchanger system 150 and/or the coupling between the first plate 208 and the second plate 218 may be via springs, a pulley system, a linkage mechanism, fasteners, welds, brazes, another suitable method, or any combination thereof. In one embodiment, the first and second plates 208 and 218 may be a single piece structure. In the extended position of the heat exchanger system 150, the partition 222 may continue to separate the third volume 220 from the fourth volume 224. The horizontal plate system 202 may be arranged in such a manner that the first plate 208 and/or the second plate 218 overlaps with a partition 232 disposed in between the first volume 212 and the second volume 214. For example, the first plate 208 and/or the second plate 218 may translate along rails 234 that guide the movement of the first plate 208 and/or the second plate 218. The partition 232 may separate the first volume 212 and the second volume 214, and the partition 232 may contain a gap or other apertures to enable the heat source 216 to couple with the heat exchanger 116 of the heat exchanger system 150. In the retracted position, the first plate 208 and the coupling between the heat sources 216 and the heat exchanger 116 of the heat exchanger system 150 may block air flow from the second volume 214 to the first volume 212. In the extended position, the second plate 218 may cover the gap or apertures in the partition 232 to block air from flowing from the second volume 214 to the first volume 212.

Another embodiment of a system to separate the first volume 212 from the second volume 214 when the heat exchanger system 150 is in the extended position is illustrated in FIG. 9. Specifically, FIG. 9 is a perspective view of an embodiment of a packaged unit 250 that includes a vertical plate system 252. The vertical plate system 252 may be disposed in a first volume 254 that also contains a heat source 256. The vertical plate system 252 includes a plate 258 configured to move in a direction 260. For example, when the heat exchanger system 150 is in the retracted position, the plate 258 may be in a first position above the heat source 256. When the heat exchanger system 150 translates to the extended position, which may expose the heat source 256 to the second volume 264, the plate 258 moves downward to a second position to block air flow from the first volume 254 to the second volume 264 and vice versa. When the heat exchanger system 150 is in the retracted position, the plate 258 moves upwards back to the first position to enable the heat source 256 to couple with the heat exchanger 116 of the heat exchanger system 150. The packaged unit 250 may use a vertical translation mechanism 266 to enable the plate 258 to move in the direction 260. For example, the heat exchanger system 150 may be coupled to an adapter plate 268 that may move with the heat exchanger system 150 as the heat exchanger system 150 translates between the extended and retracted positions. In the retracted position, the plate 258 and the adapter plate 268 may overlap with a partition 270 that separates the first volume 254 from the second volume 264. As discussed above, the partition 270 may include a gap or other apertures to enable the heat source 256 to couple with a heat exchanger 116 of the heat exchanger system 150 disposed in the second volume 264. The gap or apertures may allow air flow into the first volume 254 when the heat source 256 decouples from the heat exchanger 116 of the heat exchanger system 150. Thus, in the extended position, the plate 258 translates downward to obstruct or close the gap or apertures in the partition 270 to block air flow into the first volume 254 from the second volume 264 and vice versa.

To illustrate the movement of the plate 258, FIG. 10 is a perspective view of the packaged unit 250 when the heat exchanger system 150 is in the extended position. As shown in FIG. 10, the plate 258 has moved in the direction 280 to the second position. As such, the plate 258 closes or blocks the gap or apertures between the first volume 254 and the second volume 264. For example, as the adapter plate 268 moves with the heat exchanger system 150 when the heat exchanger system 150 translates to the extended position, the plate 258 may move in the direction 280. To this end, the plate 258 may be coupled to the adapter plate 268 via springs, a pulley system, a linkage mechanism, actuators that may be controlled by a position control synchronous motor and/or direct current motor, another suitable component, or any combination thereof to enable the plate 258 to move in the direction 280 when the adapter plate 268 moves. In some embodiments, the plate 258 may slide along rails 282 to guide the plate 258 to move in the direction 280 along the partition 270.

In the packaged units 200 and 250, the respective heat sources 216, 256 may remain within the respective first volumes 212, 254, even when decoupled from the corresponding heat exchangers 116. As a result, couplings, such as fuel lines, between the respective heat sources 216, 256 and other components may be via fixed gas connectors, metal piping, tubing of another material, another coupling component, or any combination thereof.

As previously noted, in packaged units that include the systems discussed above, translating the heat exchanger system outside of the internal volume of the packaged unit may expose the heat exchanger system to external elements. To protect the heat exchanger system when it is in the extended position, the packaged unit and/or the heat exchanger system may include a protection system that shrouds the heat exchanger system. FIGS. 11-16 illustrates different embodiments of the protection system that may be utilized for the heat exchanger system.

FIG. 11 illustrates an embodiment of a packaged unit 300 that uses a protection system 302. The protection system 302 is configured to enclose a heat exchanger system that is moved in and out of a housing 304 of the packaged unit 300. The protection system 302 may be coupled to an opening 306 disposed on a side of the packaged unit 300 through which the heat exchanger system may translate. The protection system 302 may also be coupled to the heat exchanger system such that the protection system 302 adjusts its configuration based on the position of the heat exchanger. For example, FIG. 11 illustrates the protection system 302 in an extended position, such as during a cooling mode of the packaged unit 300 when the heat exchanger is also in the extended position. To enable the protection system 302 to adjust its configuration, the protection system 302 in the illustrated embodiment include bellows 308. The bellows 308 expands to provide protection of the heat exchanger system in the extended position. Additionally, the bellows 308 is configured to collapse or fold to enable the protection system 302 to compress into the housing 304 when the heat exchanger system is in the retracted position.

To illustrate the protection system 302 compressed into the housing 304, FIG. 12 illustrates the packaged unit 300 with the protection system 302 in the compressed configuration. The compressed configuration may occur when the heat exchanger system is in the retracted position, such as during operation of a heating mode of the packaged unit 300. In this configuration, the bellows 308 is collapsed such that the protection system 302 is compressed into the housing 306 of the packaged unit 300. To enable the flexibility to fold and strength to protect the heat exchanger system, the bellows may be made of PVC, fiberglass, nylon, rubber, canvas, another suitable material, or any combination thereof. Indeed, the bellows 308 may be formed from any durable yet flexible material capable of withstanding environmental elements while shielding the heat exchanger system. When the protection system 302 is compressed, a side or external surface 310 may remain exposed external to the housing 306 and continue to shield the heat exchanger system from external elements. Thus, the external surface 310 may also provide protection of the heat exchanger during the heating mode of the packaged unit 300. To provide adequate strength in protection, the external surface 310 may be made of metal, polymer, plastic, another suitable material, or any combination thereof.

Another embodiment of a protection system is illustrated in FIG. 13, which is a perspective view of a packaged unit 350. As shown in FIG. 13, a protection system 352 may include panel-like elements that are attached to a housing 354 of the packaged unit 350. The protection system 352 also include an opening 356. During cooling mode, when a heat exchanger is in the extended position, the heat exchanger may move through the opening 356 of the protection system 352 while the protection system 352 remains stationary.

For example, FIG. 14 illustrates the packaged unit 350 when the heat exchanger system 150 is moved into the opening 356 of protection system 352. The heat exchanger system 150 may extend a distance such that an external surface 360 of the heat exchanger system 150 is flush or substantially flush with an edge 362 of the protection system 352. In this manner, only the external surface 360 of the heat exchanger is externally exposed. The external surface 360 and the protection system 352 may shield the heat exchanger system 150. To block the heat exchanger system 358 from extending too far out of the opening 356, the protection system 352 may include stops, which are not shown in FIG. 14. For example, the stops may be disposed within the opening 356 and may abut against a part of the heat exchanger system 150 at a certain distance. The stops would provide a force to block the heat exchanger system 358 from further extending out of the packaged unit 350. The packaged unit 350 may also use a controller, such as the controller 156, that is programmed to move the heat exchanger system 150 and stop its position at a certain distance. When the heat exchanger system 150 has been moved to this position, the edge 362 may be substantially in contact with the perimeter of the external surface 360 to create a seal to prevent elements, such as precipitation, from entering the opening 356. To provide adequate protection of the heat exchanger system 150, the protection system 352 may be made of metal, plastic, polymer, another suitable material, or any combination thereof. Furthermore, the external surface 360 may be made of the same or a different material than that of the protection system 352.

FIG. 15 is a perspective view of a packaged unit 400 illustrating an embodiment of a protection system 402 attached to a housing 404 of the packaged unit 400. The protection system 402 includes a telescopic assembly 406 to enable the protection system 402 to extend and compress. For example, the telescopic assembly 406 includes a plurality of sections, segments, or parts that slide out from one another to extend the protection system 402 then the heat exchanger system 150 translates out of the packaged unit 400. When the heat exchanger system 150 retracts, the segments or section telescopically slide into one another to compress the protection system 402. In the extended position, the telescopic assembly 406 protects the heat exchanger system 150 enclosed within the protection system 402. The sliding segments of the telescopic assembly 406 may also provide a seal around the heat exchanger system 150 to block external elements, such as debris and/or precipitation, from entering the protection system 402. To enable the heat exchanger system 150 to move into and out of the housing 404, the protection system 402 may be attached to the packaged unit 400 at an opening 408 of the packaged unit 400.

FIG. 16 is a perspective view of the packaged unit 400 when the protection system 402 is compressed and the heat exchanger system 150 is within the housing 404. As illustrated in FIG. 16, in the retracted position, a small portion of the telescopic assembly 406 may remain exposed out of the housing 404. In addition, an external surface 410 of the heat exchanger system may remain exposed to protect the heat exchanger system 150 in the retracted position. As similarly discussed above, the external surface 410 may be made of metal, plastic, polymer, another suitable material, or any combination thereof to protect the heat exchanger system 150 within the packaged unit 400.

Although FIGS. 11-16 discusses several embodiments of a protection system, other embodiments of the protection system may be used to cover a heat exchanger system when it is in an extended position. For example, some embodiments of the protection system may combine features of FIGS. 11-16. It should be appreciated that, although the protection system is depicted as rectangular in shape in FIGS. 11-16, other embodiments may be a different shape to accommodate for the movement of the heat exchanger system, spatial or footprint considerations, or other design constrains. Furthermore, movement of the protection system, such as expansion and compression, may be controlled by a controller, such as the controller 156.

As mentioned above, a controller may be configured to control operation of a packaged unit. FIG. 17 illustrates an embodiment of a method 450 that the controller execute or perform to alternate or switch operating modes of the packaged unit. The packaged unit may begin at block 452 in a heating mode. As discussed, during the heating mode, a heat exchanger system of the packaged unit may remain within the housing of the packaged unit. The heat exchanger system may be coupled to a heat source and may operate to heat air flow within the packaged unit before the air flow exits the packaged unit. At block 454, the controller receives a signal to operate in the cooling mode. In some embodiments, the signal may be generated because of a change in a desired temperature, such as within a building or room conditioned by the packaged unit. In response to receiving the signal, at block 456, the controller translates the heat exchanger system out of the housing of the packaged unit. In some embodiments, the controller may also configure a protection system attached to the packaged unit to adjust as the position of the heat exchanger system is adjusted. For example, the controller may expand the protection system to enable the protection system to continue to enclose the heat exchanger system during the cooling mode when the heat exchanger system is external to the packaged unit. Furthermore, the controller may adjust the interior of the packaged unit, such as covering the heat source to block air flow from being directed to the heat source. After the heat exchanger is translated out of the packaged unit, the packaged unit may operate in the cooling mode, as shown at block 458. As noted above, during operation of the cooling mode, the air flow may bypass the heat exchanger and flow directly out of the packaged unit.

The method 450 discusses switching from heating mode operation to cooling mode operation of the packaged unit. A similar method may be implemented to switch from cooling mode operation to heating mode operation. That is, the controller may receive a signal to operate in heating mode and, in response, may translate the heat exchanger system from outside of the housing to within the housing of the packaged unit. Furthermore, additional steps may be added to the method 450. For example, the controller may adjust a blower of the packaged unit to operate at a lower power such that the air flow exits the blower at a lower velocity due to the lower resistance in the air flow path by virtue of the heat exchanger system being positioned external to the packaged unit in the cooling mode. Other adjustments of components within the packaged unit may also occur when switching operation modes.

As set forth above, the heat exchanger system of the present disclosure may provide one or more technical effects useful in the operation of HVAC systems, such as packaged units, having a cooling mode and a heating mode. For example, in a heating mode, the heat exchanger system may be disposed within an air flow path of the HVAC system to enable a heat exchanger to heat an air flow. As the heat exchanger structure provides hydraulic resistance that decreases a velocity of the air flow, the blower may compensate by increasing the velocity. In a cooling mode, the heat exchanger system may be translated and positioned out of the air flow path so the air flow may bypass the heat exchanger. As such, the blower may operate at a lower power to achieve a desired air flow velocity. The HVAC system may also include a protection system that encloses the heat exchanger system when the heat exchanger system is extended out of the air flow path. The protection system may thus protect the heat exchanger system during the cooling mode. 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, mounting arrangements, use of materials, colors, orientations, and the like, 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 disclosed embodiments, or those unrelated to enabling the claimed embodiments. 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, ventilating, and air conditioning (HVAC) system, comprising:

a heat exchanger configured to translate between a first position within an air flow path of the HVAC system and a second position external to the air flow path of the HVAC system.

2. The HVAC system of claim 1, wherein the heat exchanger is configured to translate via springs.

3. The HVAC system of claim 1, wherein the heat exchanger is configured to translate via a pulley system.

4. The HVAC system of claim 1, wherein the heat exchanger is configured to translate via an actuator, a position control synchronous motor, a direct current motor, or any combination thereof.

5. The HVAC system of claim 1, wherein the heat exchanger is configured to translate via a mechanical linkage system.

6. The HVAC system of claim 1, comprising a protection system configured to enclose the heat exchanger when the heat exchanger is in the second position.

7. The HVAC system of claim 6, wherein the heat exchanger is disposed within a housing, and the protection system comprises a bellows coupled to the housing on an external surface of the housing.

8. The HVAC system of claim 6, wherein the heat exchanger is disposed within a housing, and the protection system comprises a panel coupled to the housing on an external surface of the housing.

9. The HVAC system of claim 6, wherein the heat exchanger is disposed within a housing, and the protection system comprises a telescoping assembly coupled to the housing, wherein the telescoping assembly is configured to extend from the housing when the heat exchanger is in the second position.

10. The HVAC system of claim 1, comprising a blower, wherein the blower is configured to operate at a lower power when the heat exchanger is in the second position.

11. The HVAC system of claim 1, comprising a burner disposed within a housing of the HVAC system, wherein the burner is disposed within a first volume of the housing, the heat exchanger is disposed within a second volume of the housing, and the first and second volumes are separated by a partition.

12. The HVAC system of claim 11, wherein the burner and the heat exchanger are fluidly coupled through the partition when the heat exchanger is in the first position.

13. The HVAC system of claim 12, wherein the heat exchanger and the burner are decoupled from one another when the heat exchanger is in the second position.

14. The HVAC system of claim 13, comprising a plate coupled to the heat exchanger, wherein the plate is configured to translate to a blocking position between the first volume and the second volume adjacent to the burner when the heat exchanger is translated to the second position.

15. The HVAC system of claim 1, comprising a rooftop unit comprising the heat exchanger.

16. A method of operating a heating, ventilating, and air conditioning (HVAC) system, comprising:

operating the HVAC system in a first mode with a heat exchanger disposed within an air flow path; and

operating the HVAC system in a second mode with the heat exchanger positioned external to the air flow path.

17. The method of claim 16, wherein the first mode is a heating mode and the second mode is a cooling mode.

18. The method of claim 16, comprising operating a blower at a first speed when the heat exchanger is within the air flow path and operating the blower at a second speed when the heat exchanger is external to the air flow path, wherein the second speed is less than the first speed.

19. The method of claim 16, wherein the heat exchanger is linearly translated from within the air flow path in the first mode to external to the air flow path in the second mode.

20. The method of claim 16, wherein the heat exchanger is attached to a burner in the first mode and decoupled from the burner in the second mode.

21. The method of claim 20, comprising translating the heat exchanger from within the air flow path to external to the air flow path, and translating a plate from a first position to a second position, wherein the plate is adjacent to the burner in the second position.

22. The method of claim 16, comprising positioning the heat exchanger within a protection system configured to shroud the heat exchanger in the second mode.

23. A packaged heating, ventilating, and air conditioning (HVAC) unit, comprising:

a heat source disposed within a first volume of a housing of the packaged HVAC unit; and

a heat exchanger disposed within a second volume of the housing of the packaged HVAC unit, wherein the heat exchanger is configured to establish a heat exchange relationship with an air flow within the housing in a heating mode of the packaged HVAC unit, wherein the heat exchanger is configured to translate from within the second volume to a position external to the second volume in a cooling mode of the packaged HVAC unit.

24. The packaged HVAC unit of claim 23, wherein the heat exchanger is configured to couple to the heat source in the heating mode.

25. The packaged HVAC unit of claim 24, wherein the heat exchanger and the heat source are coupled to one another through a partition dividing the first volume and the second volume in the heating mode.

26. The packaged HVAC unit of claim 25, comprising a plate configured to translate along the partition to a position adjacent to the heat source in the cooling mode.

27. The packaged HVAC unit of claim 23, comprising a protection system coupled to the housing, wherein the protection system is configured to shroud the heat exchanger in the cooling mode.

28. The packaged HVAC unit of claim 27, wherein the protection system comprises a telescopic assembly, a plurality of panels, or a bellows.

29. The packaged HVAC unit of claim 23, comprising a blower disposed within the housing, wherein the blower is configured to operate at a first speed in the heating mode and a second speed in the cooling mode, wherein the first speed is greater than the second speed.

30. The packaged HVAC unit of claim 29, wherein the blower comprises a variable speed drive fan motor configured to rotate a fan at the first speed in the heating mode and the second speed in the cooling mode.