Duct-free split HVAC system with mixed-mode operation

Abstract

A split HVAC system including a single outdoor unit (ODU) configured to circulate refrigerant to a plurality of indoor units (IDUs) is provided. The system includes a controller configured to perform operations, including transmitting a first command signal from one or more IDUs to the ODU, the first command signal corresponding to a first operating mode; setting, at the ODU, the first operating mode based on the first command signal; transmitting, to the ODU, a second command signal from at least one other IDU while one or more IDUs includes the first command signal, the second command signal corresponding to a second operating mode; setting, at the ODU, the second operating mode based on the second command signal; operating in the second operating mode; and permitting, at the ODU after operating in the second operating mode, the first operating mode based on the first command signal.

Description

FIELD OF THE INVENTION

[0001] The present subject matter relates generally to heating, ventilation, and air-conditioning systems, and more particularly to duct-free or split HVAC systems having multiple indoor units.BACKGROUND OF THE INVENTION

[0002] Duct-free split heating, ventilation, and air-conditioning (DFS HVAC) systems, or ductless mini-split HVAC systems, generally include one or more indoor units (IDU) and a single outdoor unit (ODU). The ODU is configured to pump refrigerant to the IDUs. The IDU is configured to transfer heat, and the refrigerant removes the thermal energy from the room back to the ODU and, in another operating mode, provides thermal energy to the room, such as to operate as an air conditioner and heat pump. The IDU is configured to operate a fan to blow cooled or heated air into the room.

[0003] DFS HVAC systems offer several benefits, such as providing HVAC to a building without requiring installation and routing of ducts through walls or between floors of a building. DFS HVAC systems provide zoned climate control, such as to permit cooling or heating of the room in which the indoor unit is placed. DFS HVAC systems may generally be quieter than central HVAC systems.

[0004] However, similar to central HVAC systems, since the DFS HVAC system utilizes a common ODU for heat transfer and moving refrigerant, a DFS HVAC system can operate either in a cooling mode or in a heating mode. For instance, when operating, either all of the IDUs will provide air conditioning, or all of the IDUs will provide heating, rather than some IDUs operating in a cooling mode and others operating in a heating mode. In some instances, when one or more IDUs among multiple IDUs is set to a different mode from the other IDUS, the DFS HVAC system may cease to operate until all IDUs are set to matching modes. As such, multiple IDUs of a DFS HVAC system are dependent on one another as to whether each IDU can operate in a cooling mode or a heating mode.

[0005] As the multiple IDUs are positioned at various rooms and spaces of a building, and each IDU generally includes a controller for activating and de-activating operation, changing fan speeds, or altering temperature, a user may have the impression that the IDUs operate independently from one another, such that each IDU should provide cooling or heating without regard for the operating mode of another IDU. Such impression may lead to perceived or actual user problems, such as mis-matched IDU operating modes leading to a non-operating DFS HVAC system, or inconveniences when changing between operating modes as seasons change, or a desire to change an operating mode of the IDU based on room-specific temperature conditions.

[0006] An improved DFS HVAC system addressing one or more of the aforementioned issues would be beneficial and advantageous.BRIEF DESCRIPTION OF THE INVENTION

[0007] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0008] An aspect of the present disclosure is directed to a split heating, ventilation, and air-conditioning system including a single outdoor unit (ODU) configured to circulate refrigerant to a plurality of indoor units (IDUs) for heat exchange. The system includes a controller configured to perform operations. The operations include transmitting, to the ODU, a first command signal from one or more IDUs of the plurality of IDUs, the first command signal corresponding to a first operating mode, wherein a first IDU of the plurality of IDUs corresponds to the first command signal corresponding thereto; setting, at the ODU, the first operating mode based on the first command signal; transmitting, to the ODU, a second command signal from at least one IDU of the plurality of IDUs, and fewer than all IDUs of the plurality of IDUs, and while one or more IDUs of the plurality of IDUs is the first IDU corresponding to the first command signal, the second command signal corresponding to a second operating mode, wherein a second IDU of the plurality of IDUs corresponds to the second command signal corresponding thereto, and wherein the first and second operating mode correspond to either a cooling mode or a heating mode, and wherein the first and second operating mode are dissimilar to one another; setting, at the ODU, the second operating mode based on the second command signal; operating the ODU and the second IDU in the second operating mode based on the second command signal; and permitting, at the ODU after operating the ODU in the second operating mode, the first operating mode based on the first command signal.

[0009] An aspect of the present disclosure is directed to a computer-implemented method for mixed-mode operation for a duct-free split heating, ventilation, and air-conditioning system including a single outdoor unit (ODU) configured to circulate refrigerant to a plurality of indoor units (IDUs) for heat exchange. The method includes transmitting, to the ODU, a first command signal from one or more IDUs of the plurality of IDUs, the first command signal corresponding to a first operating mode, wherein a first IDU of the plurality of IDUs corresponds to the first command signal corresponding thereto; setting, at the ODU, the first operating mode based on the first command signal; transmitting, to the ODU, a second command signal from at least one IDU of the plurality of IDUs, and fewer than all IDUs of the plurality of IDUs, and while one or more IDUs of the plurality of IDUs is the first IDU corresponding to the first command signal, the second command signal corresponding to a second operating mode, wherein a second IDU of the plurality of IDUs corresponds to the second command signal corresponding thereto, and wherein the first and second operating mode correspond to either a cooling mode or a heating mode, and wherein the first and second operating mode are dissimilar to one another; setting, at the ODU, the second operating mode based on the second command signal; operating the ODU and the second IDU in the second operating mode based on the second command signal; and permitting, at the ODU after operating the ODU in the second operating mode, the first operating mode based on the first command signal.

[0010] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

[0012] FIG. 1 provides an exemplary schematic embodiment of a duct-free split heating, ventilation, and air conditioning system in accordance with aspects of the present disclosure;

[0013] FIG. 2A provides an exemplary schematic embodiment of the system in a first operating state in accordance with aspects of the present disclosure;

[0014] FIG. 2B provides an exemplary schematic embodiment of the system in a second operating state in accordance with aspects of the present disclosure;

[0015] FIG. 3 provides a flowchart outlining steps of a method for mixed-mode operation of a duct-free split heating, ventilation, and air conditioning system in accordance with aspects of the present disclosure; and

[0016] FIG. 4 provides a schematic diagram depicting transitions between heating and cooling modes of a duct-free split heating, ventilation, and air conditioning system in accordance with aspects of the present disclosure.

[0017] Use of the same of similar reference numerals in the figures denotes the same or similar features unless the context indicates otherwise.DETAILED DESCRIPTION

[0018] Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0019] As used herein, the terms “first,”“second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). In addition, here and throughout the specification and claims, range limitations may be combined and / or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. The singular forms “a,”“an,” and “the” include plural references unless the context clearly dictates otherwise.

[0020] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “generally,”“about,”“approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components and / or systems. For example, the approximating language may refer to being within a 10 percent margin, i.e., including values within ten percent greater or less than the stated value. In this regard, for example, when used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction, e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, e.g., clockwise, or counterclockwise, with the vertical direction V.

[0021] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” In addition, references to “an embodiment” or “one embodiment” does not necessarily refer to the same embodiment, although it may. Any implementation described herein as “exemplary” or “an embodiment” is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0022] Embodiments of a duct-free or ductless split heating, ventilation, and air-conditioning (DFS HVAC) system 100 are provided herein that address one or more of the aforementioned issues. Embodiments of the DFS HVAC system include an outdoor unit (ODU) 10 and a plurality of indoor units (IDUs) 20. The ODU 10 is configured to circulate refrigerant to the IDUs 20 for heat exchange, such as forming a refrigeration loop or heat pump. One or more conduits 12 are configured as a refrigeration loop to fluidly couple the ODU 10 to the IDUs 20 to flow refrigerant for heat transfer at each IDU 20. As generally understood in the art, the refrigeration loop is alternately operated as a refrigeration assembly and performing a refrigeration cycle, and thus providing cooled air conditioning, or operated as a heat pump, and thus performing a heat pump cycle, and thus providing heating.

[0023] FIGS. 2A-2B illustrate an exemplary schematic embodiment of the system 100 in different states of operation. As further described herein, the plurality of IDUs 20 are in a first operating mode, such as provided schematically by first IDU 21 in FIGS. 2A-2B, or switched from the first operating mode to a second operating mode, such as provided schematically at second IDU 22 in FIG. 2B. In an exemplary schematic embodiment, the ODU 10 includes a heat exchanger 30, a condenser 32, and a fan 34. The IDUs 20 each generally include a heat exchanger 40, an evaporator 42, and a fan 44. When the refrigeration loop is operating in a cooling mode and thus performs a refrigeration cycle, the IDU heat exchanger 40 acts as an evaporator and the ODU heat exchanger 30 acts as a condenser. Alternatively, when the assembly is operating in a heating mode and thus performs a heat pump cycle, the IDU heat exchanger 40 acts as a condenser and the ODU heat exchanger 30 acts as an evaporator. The ODU and IDU heat exchangers 30, 40 may each include coils through which a refrigerant may flow for heat exchange purposes, as is generally understood. The heat exchangers 30, 40 may generally include fans, compressors, expanders, valves, louvers, etc., as generally understood.

[0024] Operation of system 100 may be controlled by a processing device such as a controller 36, 46. Controller 36, 46 may be in communication (via for example a suitable wired or wireless connection) to such components of the system 100, such as heat exchangers 30, 40, or communication between the ODU 10 and the IDU 20. By way of example, the controller 46 may include a memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of unit 10. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. In various embodiments, steps of a method for operating the system 100 (method 1000) provided herein are stored or executed as programming instructions at one or more controllers 36, 46, computing devices, or computing networks.

[0025] The IDU 20 may additionally include a control panel 48 having one or more user inputs, such as buttons, knobs, touchscreens, displays, remote receivers, or communications devices. The user inputs may be in communication with the controller 46 for the respective IDU 20. A user of the IDU 20 may interact with the control panel 48 to operate the IDU 20. User commands may be transmitted between the control panel 48 and controller 46, and between the ODU controller 36 and the IDU controller 46, to facilitate operation of the IDU 20 based on such user commands, such as further described herein.

[0026] Embodiments of the system 100 include the controllers 36, 46 configured to dynamically set an operating mode (i.e., a heating mode or a cooling mode) at the ODU 10 based on the operating modes of the IDUs 20, a current call or command signal for heating or cooling status, and user interactions generating one or more command signals at the IDU 20, such as an operating mode selection or a temperature set point.

[0027] Referring now to FIG. 3, a schematic flowchart outlining steps of a method 1000 for mixed-mode operation for a duct-free split heating, ventilation, and air-conditioning (DFS HVAC) system is provided. Embodiments of the DFS HVAC system generally include a single ODU (e.g., ODU 10) operably coupled to a plurality of IDUs (e.g., IDUs 20), such as generally provided herein. The ODU is configured to operate in a heating mode and a cooling mode. As generally understood, the ODU is configured to operate in either the heating mode or the cooling mode at a given point or period of time.

[0028] Method 1000 includes at 1010 transmitting, to the ODU, a first command signal from the plurality of IDUs. The first command signal corresponds to a first operating mode, such as a heating mode or a cooling mode. For instance, method 1000 at 1010 includes a user interaction to set the IDUs to a cooling mode. Alternately, in various embodiments, method 1000 at 1010 includes a user interaction to set the IDUs to a heating mode. The first command signal may further include a temperature set point, or corresponding load or cycle, associated with the operating mode selection, or changes thereto.

[0029] In some embodiments, the user may set all IDUs to the desired operating mode. However, in some embodiments, some IDUs may be set to an IDLE or OFF condition. It should be appreciated that, as used herein, first and second IDUs 21, 22 refer to IDUs in a respective first operating mode or second operating mode, and one or more other or additional IDUs may include no operating mode (e.g., IDLE or OFF).

[0030] Method 1000 includes at 1020 setting, at the ODU, the first operating mode based on the first command signal. For instance, step 1020 sets the ODU to the cooling mode based on the user interaction for the IDU to operate in the cooling mode to provide cool air based on a temperature set point, fan setting, or other operation. Step 1020 permits operation of the ODU and first IDU in the first operating mode based on the first command signal. Particularly, method 1000 permits performance of the first operation at the ODU and first IDU based on the first operating mode and first command signal, e.g., to provide cooling pursuant to a temperature set point (e.g., one or more temperature set points corresponding to each first IDU). Setting and permitting operation of the ODU in the first operating mode inhibits operation of the ODU in a second operating mode.

[0031] In some embodiments, method 1000 may include at 1025 performing, at the ODU and first IDU, the first operation in the first operating mode based on the first command signal. However, it should be appreciated that performance of the first operation is based on detected ambient temperatures and temperature set points.

[0032] Alternatively, in various embodiments, method 1000 at 1020 sets the ODU to the heating mode based on the user interaction for the IDU to operate in the heating mode to provide heated air, and method 1000 at 1025 performs the first operation as the heating operation.

[0033] Steps 1010, 1020 set and permit the ODU and one or more of the plurality of IDUs to perform the first operation based on the first operating mode, such as to provide cool air (in a cooling mode) or heated air (in a heating mode) pursuant to the selected cooling or heating operating mode and a selected temperature set point.

[0034] Method 1000 includes at 1030 transmitting, to the ODU, a second command signal from at least one IDU, and fewer than all IDUs of the plurality of IDUs. The second command signal corresponds to a second operating mode different from the first operating mode. If the first operating mode corresponds to a cooling mode, the second operating mode corresponds to a heating mode. Alternately, if the first operating mode corresponds to a heating mode, the second operating mode corresponds to a cooling mode.

[0035] Referring to FIG. 3, and furthermore referring briefly to FIG. 2A, in an exemplary embodiment, the plurality of IDUs 20 are set similarly to the first operating mode, corresponding to method 1000 at 1010, 1020, such as illustrated as the plurality of first IDUs 21. Referring to FIG. 2B and to FIG. 3, step 1030 includes at least one of first IDUs 21 receiving user selections corresponding to a second command signal for operating in the second operating mode, such as illustrated as second IDU 22. For instance, referring to FIG. 2A, steps 1010, 1020 set the plurality of first IDUs 21 to a cooling mode, and step 1025 may perform the cooling operation. Referring to FIG. 2B, step 1030 changes one or more of the first IDUs 21 to the second IDU 22 in a heating mode. As provided herein, it should be appreciated that, in other embodiments, steps 1010, 1020 set the first IDUs 21 to a heating mode, and step 1030 sets one or more of the first IDUs 21 to the second IDU 22 in a cooling mode.

[0036] Referring still to FIG. 2B and FIG. 3, after performing steps 1010, 1020, and 1030, the ODU is in a state in which one or more IDUs are calling for a first operation (e.g., first IDU 21) based on the first operating mode (e.g., call for cooling) and one or more other IDUs are calling for a second operation based (e.g., second IDU 22) on the second operating mode (e.g., call for heating).

[0037] In some embodiments, the second command signal generated and transmitted at step 1030 generates a time-limit for remaining or continued operation of the ODU and first IDU in the first operating mode. For instance, step 1030 may generate a time-limit for continued operation of the ODU and first IDU in the first operating mode in step 1025. When the time-limit is achieved, first operation is ceased without regard for whether a temperature set point corresponding to the first command is achieved. Stated differently, the time limit provides a time range within which the first operation is to achieve the temperature set point before the ODU and first IDU cease the first operation.

[0038] Method 1000 includes at 1040 setting, at the ODU, the second operating mode based on the second command signal. For instance, step 1040 sets the ODU to the heating mode based on the user interaction for the IDU to operate in the heating mode to provide heated air based on a temperature set point, fan setting, or other operation. Step 1040 permits operation of the ODU and second IDU in the second operating mode based on the second command signal. Particularly, method 1000 permits performance of the second operation at the ODU and second IDU based on the second operating mode and second command signal, e.g., to provide heating pursuant to a temperature set point (e.g., one or more temperature set points corresponding to each second IDU). Setting and permitting operation of the ODU in the second operating mode inhibits operation of the ODU in the first operating mode. As such, step 1040 may include inhibiting operation of the ODU and first IDU in the first operating mode.

[0039] Method 1000 includes at 1045 operating the ODU and the second IDU in the second operating mode based on the second command signal (e.g., at 1030) after inhibiting or determining non-operation of the ODU and first IDU in the first operating mode. In some embodiments, step 1045 includes operating the ODU and the second IDU for a predetermined period of time in which a time-limit is provided after which the second operation is stopped without regard for whether the temperature set point is achieved. Stated differently, the predetermined period of time provides a time range within which the second operation is to achieve the temperature set point before the ODU and second IDU cease the second operation.

[0040] In some embodiments, the time-limits or time-ranges may differ relative to the first and second operations. For instance, the predetermined period of time may differ based on a quantity of IDUs calling for the first operating mode (e.g., quantity of first IDUs 21) versus a quantity of IDUs calling for the second operating mode (e.g., quantity of first IDUs 22).

[0041] In still some embodiments, the first IDU, first operating mode, and first operation may correspond to a first duty cycle rate greater than a second duty cycle rate corresponding to the second IDU, second operating mode, and second operation. For instance, during cold-weather periods (e.g., winter), the first duty cycle rate may correspond to a heating operation as the majority or greater operation versus a cooling operation. In another instance, during warm-weather periods (e.g., summer), the first duty cycle rate may correspond to a cooling operation as the majority or greater operation versus a heating operation.

[0042] In various embodiments, method 1000 includes one or more iterations of steps permitting the first operation and inhibiting the second operation, and permitting the second operation and inhibiting the first operation.

[0043] In some embodiments, method 1000 may provide prioritization of the second command signal and operation of the second IDU over the first command signal and operation of the first IDUs based on a temporal proximity from which the command signal is obtained at the ODU. For instance, steps 1010, 1020 may generally correspond to an operating mode set for a longer term without changing the operating mode, while step 1030 may correspond to a shorter term operating mode.

[0044] Referring to FIG. 4, a schematic state diagram 400 depicting transitions between heating, idle, and cooling states of the system 100 is provided. The system 100 may include the plurality of IDUs 20 and ODU 10 set to a heating mode. The IDUs 20 may receive, from a user input, call for cool and heat inactive or deactivation. The system may idle for a period of time before call for cool is active and cooling is provided, such as may correspond to a transition from cold-weather conditions to warm-and hot-weather conditions. The IDUs 20 may receive, from a user input, call for heat and cool inactive or deactivation. The system may idle for a period of time before call for heat is active and heating is provided, such as may correspond to a transition from hot-weather conditions to cool-or cold-weather conditions.

[0045] In an exemplary embodiment of operation of the system 100 and method 1000, a user may set the plurality of IDUs 20 to a first operating mode corresponding to a heating mode during cold-weather months. The cold-weather months may generally include ambient outside temperatures ranging, e.g., below 50 degrees Fahrenheit. Accordingly, the plurality of IDUs 20 are set for similar operation, such as first IDUs 21, in accordance with FIG. 2A. Method 1000 at 1010, 1020, and 1025 receives command signals, permits operation, and performs operations at the ODU and IDUs based on the first operating mode (e.g., heating based on one or more temperature set points).

[0046] However, heatwaves, warm-weather conditions, or other phenomena may result in periods during which the ambient outside temperatures are relatively high, e.g., above 50 degrees Fahrenheit. Additionally, or alternatively, conditions within, or entering, the building at which the system is installed may result in rooms or areas having perceptibly different indoor temperatures. For instance, solar radiation through windows, cooking in a kitchen, or upper floors may receive more heat than other areas of the building, such that a user may desire cooling for the particular area. The user may set one or more of the IDUs to a second operating mode correspond to a cooling mode. Accordingly, the plurality of IDUs 20 changed from the first IDUs 21 in the heating mode to a second IDU 22 in a cooling mode, such as in accordance with FIG. 2B, such as provided at step 1030.

[0047] The system including the ODU and first IDUs set to the heating mode receive, from a second command signal, a mode change to cooling (i.e., the first IDU calling for heating changed to the second IDU calling for cooling). Additionally, or alternatively, a set temperature is lowered, such as to command cooling from the second IDU. The ODU receives the command call for cooling and switches to the cooling mode. In some embodiments, active heating operation becomes time-limited with the command call, such as to prioritize operation of the second IDU to provide cooling. After a period of time, or after the cooling temperature set point is achieved, cooling operation is discontinued and the system switches back to the heating operation.

[0048] In some embodiments, method 1000 includes at 1050 monitoring a duty cycle rate and at 1052 determining whether a duty cycle rate threshold is exceeded within a period of time prior to transmitting the second command signal (step 1030). When the duty cycle rate threshold is exceeded, the corresponding duty cycle may be designated as the first operating mode. For instance, when a duty cycle rate corresponding to a heating operation exceeds the threshold, the heating operation is designated as the first operating mode, and the cooling operation is designated as the second operating mode. Steps for operation based on the second operating mode may include prioritization and time-limits in accordance with the second operating mode described in method 1000.

[0049] Determining a greater or majority duty cycle may avoid confusion as to which operating mode is a majority state (e.g., corresponding to the season or predominate ambient conditions) and which is a more transient state (e.g., corresponding to ambient temperature fluctuations and temperature outliers). Additionally, or alternatively, user confusion and dissatisfaction may be avoided by prioritizing the minority operating mode and limiting a delay, or more expediently changing, from the first operating mode to the second operating mode, such as to address the ambient conditions associated with the transient or outlier state.

[0050] Steps of method 1000 described herein may be stored at one or more controllers 36, 46, external computing devices, network devices, or other computing systems, in whole at a single computing device or as distributed code across a plurality of computing devices. Steps of method 1000 provide operability and performance improvements beyond those of user or manual operation or performance. For instance, determinations of first and second operating mode, or majority and minority operating mode, may be impracticable by a user, or impracticable on a repeated and constant performance basis, or unduly bound to user subjectivity as to which operating mode should or will receive priority.

[0051] Embodiments of the system 100 and method 1000 such as provided herein may provide mixed heating and cooling mode operation for a duct-free split HVAC system having a plurality of indoor units operably connected to a single outdoor unit. The mixed mode operation may facilitate heating and cooling in a manner that may be perceived as parallel heating and cooling operation. Embodiments depicted and described herein may avoid user confusion, unnecessary service calls, and user dissatisfaction that may be associated with non-operation of the system for addressing conditions in a single room or minority of rooms or areas in contrast to a majority of rooms or areas. Still various embodiments of the system 100 and method 1000 are configured to perform steps or operations that improve operation over non-computer or non-controller executed steps or operations (e.g., human inputs, perceptions, and changes), such as facilitating operation perceived as parallel heating and cooling operation from a duct-free split HVAC system.

[0052] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Examples

Embodiment Construction

[0018]Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0019]As used herein, the terms “first,”“second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are...

FIELD OF THE INVENTION

[0001] The present subject matter relates generally to heating, ventilation, and air-conditioning systems, and more particularly to duct-free or split HVAC systems having multiple indoor units.BACKGROUND OF THE INVENTION

[0002] Duct-free split heating, ventilation, and air-conditioning (DFS HVAC) systems, or ductless mini-split HVAC systems, generally include one or more indoor units (IDU) and a single outdoor unit (ODU). The ODU is configured to pump refrigerant to the IDUs. The IDU is configured to transfer heat, and the refrigerant removes the thermal energy from the room back to the ODU and, in another operating mode, provides thermal energy to the room, such as to operate as an air conditioner and heat pump. The IDU is configured to operate a fan to blow cooled or heated air into the room.

[0003] DFS HVAC systems offer several benefits, such as providing HVAC to a building without requiring installation and routing of ducts through walls or between floors of a building. DFS HVAC systems provide zoned climate control, such as to permit cooling or heating of the room in which the indoor unit is placed. DFS HVAC systems may generally be quieter than central HVAC systems.

[0004] However, similar to central HVAC systems, since the DFS HVAC system utilizes a common ODU for heat transfer and moving refrigerant, a DFS HVAC system can operate either in a cooling mode or in a heating mode. For instance, when operating, either all of the IDUs will provide air conditioning, or all of the IDUs will provide heating, rather than some IDUs operating in a cooling mode and others operating in a heating mode. In some instances, when one or more IDUs among multiple IDUs is set to a different mode from the other IDUS, the DFS HVAC system may cease to operate until all IDUs are set to matching modes. As such, multiple IDUs of a DFS HVAC system are dependent on one another as to whether each IDU can operate in a cooling mode or a heating mode.

[0005] As the multiple IDUs are positioned at various rooms and spaces of a building, and each IDU generally includes a controller for activating and de-activating operation, changing fan speeds, or altering temperature, a user may have the impression that the IDUs operate independently from one another, such that each IDU should provide cooling or heating without regard for the operating mode of another IDU. Such impression may lead to perceived or actual user problems, such as mis-matched IDU operating modes leading to a non-operating DFS HVAC system, or inconveniences when changing between operating modes as seasons change, or a desire to change an operating mode of the IDU based on room-specific temperature conditions.

[0006] An improved DFS HVAC system addressing one or more of the aforementioned issues would be beneficial and advantageous.BRIEF DESCRIPTION OF THE INVENTION

[0007] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0008] An aspect of the present disclosure is directed to a split heating, ventilation, and air-conditioning system including a single outdoor unit (ODU) configured to circulate refrigerant to a plurality of indoor units (IDUs) for heat exchange. The system includes a controller configured to perform operations. The operations include transmitting, to the ODU, a first command signal from one or more IDUs of the plurality of IDUs, the first command signal corresponding to a first operating mode, wherein a first IDU of the plurality of IDUs corresponds to the first command signal corresponding thereto; setting, at the ODU, the first operating mode based on the first command signal; transmitting, to the ODU, a second command signal from at least one IDU of the plurality of IDUs, and fewer than all IDUs of the plurality of IDUs, and while one or more IDUs of the plurality of IDUs is the first IDU corresponding to the first command signal, the second command signal corresponding to a second operating mode, wherein a second IDU of the plurality of IDUs corresponds to the second command signal corresponding thereto, and wherein the first and second operating mode correspond to either a cooling mode or a heating mode, and wherein the first and second operating mode are dissimilar to one another; setting, at the ODU, the second operating mode based on the second command signal; operating the ODU and the second IDU in the second operating mode based on the second command signal; and permitting, at the ODU after operating the ODU in the second operating mode, the first operating mode based on the first command signal.

[0009] An aspect of the present disclosure is directed to a computer-implemented method for mixed-mode operation for a duct-free split heating, ventilation, and air-conditioning system including a single outdoor unit (ODU) configured to circulate refrigerant to a plurality of indoor units (IDUs) for heat exchange. The method includes transmitting, to the ODU, a first command signal from one or more IDUs of the plurality of IDUs, the first command signal corresponding to a first operating mode, wherein a first IDU of the plurality of IDUs corresponds to the first command signal corresponding thereto; setting, at the ODU, the first operating mode based on the first command signal; transmitting, to the ODU, a second command signal from at least one IDU of the plurality of IDUs, and fewer than all IDUs of the plurality of IDUs, and while one or more IDUs of the plurality of IDUs is the first IDU corresponding to the first command signal, the second command signal corresponding to a second operating mode, wherein a second IDU of the plurality of IDUs corresponds to the second command signal corresponding thereto, and wherein the first and second operating mode correspond to either a cooling mode or a heating mode, and wherein the first and second operating mode are dissimilar to one another; setting, at the ODU, the second operating mode based on the second command signal; operating the ODU and the second IDU in the second operating mode based on the second command signal; and permitting, at the ODU after operating the ODU in the second operating mode, the first operating mode based on the first command signal.

[0010] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

[0012] FIG. 1 provides an exemplary schematic embodiment of a duct-free split heating, ventilation, and air conditioning system in accordance with aspects of the present disclosure;

[0013] FIG. 2A provides an exemplary schematic embodiment of the system in a first operating state in accordance with aspects of the present disclosure;

[0014] FIG. 2B provides an exemplary schematic embodiment of the system in a second operating state in accordance with aspects of the present disclosure;

[0015] FIG. 3 provides a flowchart outlining steps of a method for mixed-mode operation of a duct-free split heating, ventilation, and air conditioning system in accordance with aspects of the present disclosure; and

[0016] FIG. 4 provides a schematic diagram depicting transitions between heating and cooling modes of a duct-free split heating, ventilation, and air conditioning system in accordance with aspects of the present disclosure.

[0017] Use of the same of similar reference numerals in the figures denotes the same or similar features unless the context indicates otherwise.DETAILED DESCRIPTION

[0018] Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0019] As used herein, the terms “first,”“second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). In addition, here and throughout the specification and claims, range limitations may be combined and / or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. The singular forms “a,”“an,” and “the” include plural references unless the context clearly dictates otherwise.

[0020] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “generally,”“about,”“approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components and / or systems. For example, the approximating language may refer to being within a 10 percent margin, i.e., including values within ten percent greater or less than the stated value. In this regard, for example, when used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction, e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, e.g., clockwise, or counterclockwise, with the vertical direction V.

[0021] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” In addition, references to “an embodiment” or “one embodiment” does not necessarily refer to the same embodiment, although it may. Any implementation described herein as “exemplary” or “an embodiment” is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0022] Embodiments of a duct-free or ductless split heating, ventilation, and air-conditioning (DFS HVAC) system 100 are provided herein that address one or more of the aforementioned issues. Embodiments of the DFS HVAC system include an outdoor unit (ODU) 10 and a plurality of indoor units (IDUs) 20. The ODU 10 is configured to circulate refrigerant to the IDUs 20 for heat exchange, such as forming a refrigeration loop or heat pump. One or more conduits 12 are configured as a refrigeration loop to fluidly couple the ODU 10 to the IDUs 20 to flow refrigerant for heat transfer at each IDU 20. As generally understood in the art, the refrigeration loop is alternately operated as a refrigeration assembly and performing a refrigeration cycle, and thus providing cooled air conditioning, or operated as a heat pump, and thus performing a heat pump cycle, and thus providing heating.

[0023] FIGS. 2A-2B illustrate an exemplary schematic embodiment of the system 100 in different states of operation. As further described herein, the plurality of IDUs 20 are in a first operating mode, such as provided schematically by first IDU 21 in FIGS. 2A-2B, or switched from the first operating mode to a second operating mode, such as provided schematically at second IDU 22 in FIG. 2B. In an exemplary schematic embodiment, the ODU 10 includes a heat exchanger 30, a condenser 32, and a fan 34. The IDUs 20 each generally include a heat exchanger 40, an evaporator 42, and a fan 44. When the refrigeration loop is operating in a cooling mode and thus performs a refrigeration cycle, the IDU heat exchanger 40 acts as an evaporator and the ODU heat exchanger 30 acts as a condenser. Alternatively, when the assembly is operating in a heating mode and thus performs a heat pump cycle, the IDU heat exchanger 40 acts as a condenser and the ODU heat exchanger 30 acts as an evaporator. The ODU and IDU heat exchangers 30, 40 may each include coils through which a refrigerant may flow for heat exchange purposes, as is generally understood. The heat exchangers 30, 40 may generally include fans, compressors, expanders, valves, louvers, etc., as generally understood.

[0024] Operation of system 100 may be controlled by a processing device such as a controller 36, 46. Controller 36, 46 may be in communication (via for example a suitable wired or wireless connection) to such components of the system 100, such as heat exchangers 30, 40, or communication between the ODU 10 and the IDU 20. By way of example, the controller 46 may include a memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of unit 10. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. In various embodiments, steps of a method for operating the system 100 (method 1000) provided herein are stored or executed as programming instructions at one or more controllers 36, 46, computing devices, or computing networks.

[0025] The IDU 20 may additionally include a control panel 48 having one or more user inputs, such as buttons, knobs, touchscreens, displays, remote receivers, or communications devices. The user inputs may be in communication with the controller 46 for the respective IDU 20. A user of the IDU 20 may interact with the control panel 48 to operate the IDU 20. User commands may be transmitted between the control panel 48 and controller 46, and between the ODU controller 36 and the IDU controller 46, to facilitate operation of the IDU 20 based on such user commands, such as further described herein.

[0026] Embodiments of the system 100 include the controllers 36, 46 configured to dynamically set an operating mode (i.e., a heating mode or a cooling mode) at the ODU 10 based on the operating modes of the IDUs 20, a current call or command signal for heating or cooling status, and user interactions generating one or more command signals at the IDU 20, such as an operating mode selection or a temperature set point.

[0027] Referring now to FIG. 3, a schematic flowchart outlining steps of a method 1000 for mixed-mode operation for a duct-free split heating, ventilation, and air-conditioning (DFS HVAC) system is provided. Embodiments of the DFS HVAC system generally include a single ODU (e.g., ODU 10) operably coupled to a plurality of IDUs (e.g., IDUs 20), such as generally provided herein. The ODU is configured to operate in a heating mode and a cooling mode. As generally understood, the ODU is configured to operate in either the heating mode or the cooling mode at a given point or period of time.

[0028] Method 1000 includes at 1010 transmitting, to the ODU, a first command signal from the plurality of IDUs. The first command signal corresponds to a first operating mode, such as a heating mode or a cooling mode. For instance, method 1000 at 1010 includes a user interaction to set the IDUs to a cooling mode. Alternately, in various embodiments, method 1000 at 1010 includes a user interaction to set the IDUs to a heating mode. The first command signal may further include a temperature set point, or corresponding load or cycle, associated with the operating mode selection, or changes thereto.

[0029] In some embodiments, the user may set all IDUs to the desired operating mode. However, in some embodiments, some IDUs may be set to an IDLE or OFF condition. It should be appreciated that, as used herein, first and second IDUs 21, 22 refer to IDUs in a respective first operating mode or second operating mode, and one or more other or additional IDUs may include no operating mode (e.g., IDLE or OFF).

[0030] Method 1000 includes at 1020 setting, at the ODU, the first operating mode based on the first command signal. For instance, step 1020 sets the ODU to the cooling mode based on the user interaction for the IDU to operate in the cooling mode to provide cool air based on a temperature set point, fan setting, or other operation. Step 1020 permits operation of the ODU and first IDU in the first operating mode based on the first command signal. Particularly, method 1000 permits performance of the first operation at the ODU and first IDU based on the first operating mode and first command signal, e.g., to provide cooling pursuant to a temperature set point (e.g., one or more temperature set points corresponding to each first IDU). Setting and permitting operation of the ODU in the first operating mode inhibits operation of the ODU in a second operating mode.

[0031] In some embodiments, method 1000 may include at 1025 performing, at the ODU and first IDU, the first operation in the first operating mode based on the first command signal. However, it should be appreciated that performance of the first operation is based on detected ambient temperatures and temperature set points.

[0032] Alternatively, in various embodiments, method 1000 at 1020 sets the ODU to the heating mode based on the user interaction for the IDU to operate in the heating mode to provide heated air, and method 1000 at 1025 performs the first operation as the heating operation.

[0033] Steps 1010, 1020 set and permit the ODU and one or more of the plurality of IDUs to perform the first operation based on the first operating mode, such as to provide cool air (in a cooling mode) or heated air (in a heating mode) pursuant to the selected cooling or heating operating mode and a selected temperature set point.

[0034] Method 1000 includes at 1030 transmitting, to the ODU, a second command signal from at least one IDU, and fewer than all IDUs of the plurality of IDUs. The second command signal corresponds to a second operating mode different from the first operating mode. If the first operating mode corresponds to a cooling mode, the second operating mode corresponds to a heating mode. Alternately, if the first operating mode corresponds to a heating mode, the second operating mode corresponds to a cooling mode.

[0035] Referring to FIG. 3, and furthermore referring briefly to FIG. 2A, in an exemplary embodiment, the plurality of IDUs 20 are set similarly to the first operating mode, corresponding to method 1000 at 1010, 1020, such as illustrated as the plurality of first IDUs 21. Referring to FIG. 2B and to FIG. 3, step 1030 includes at least one of first IDUs 21 receiving user selections corresponding to a second command signal for operating in the second operating mode, such as illustrated as second IDU 22. For instance, referring to FIG. 2A, steps 1010, 1020 set the plurality of first IDUs 21 to a cooling mode, and step 1025 may perform the cooling operation. Referring to FIG. 2B, step 1030 changes one or more of the first IDUs 21 to the second IDU 22 in a heating mode. As provided herein, it should be appreciated that, in other embodiments, steps 1010, 1020 set the first IDUs 21 to a heating mode, and step 1030 sets one or more of the first IDUs 21 to the second IDU 22 in a cooling mode.

[0036] Referring still to FIG. 2B and FIG. 3, after performing steps 1010, 1020, and 1030, the ODU is in a state in which one or more IDUs are calling for a first operation (e.g., first IDU 21) based on the first operating mode (e.g., call for cooling) and one or more other IDUs are calling for a second operation based (e.g., second IDU 22) on the second operating mode (e.g., call for heating).

[0037] In some embodiments, the second command signal generated and transmitted at step 1030 generates a time-limit for remaining or continued operation of the ODU and first IDU in the first operating mode. For instance, step 1030 may generate a time-limit for continued operation of the ODU and first IDU in the first operating mode in step 1025. When the time-limit is achieved, first operation is ceased without regard for whether a temperature set point corresponding to the first command is achieved. Stated differently, the time limit provides a time range within which the first operation is to achieve the temperature set point before the ODU and first IDU cease the first operation.

[0038] Method 1000 includes at 1040 setting, at the ODU, the second operating mode based on the second command signal. For instance, step 1040 sets the ODU to the heating mode based on the user interaction for the IDU to operate in the heating mode to provide heated air based on a temperature set point, fan setting, or other operation. Step 1040 permits operation of the ODU and second IDU in the second operating mode based on the second command signal. Particularly, method 1000 permits performance of the second operation at the ODU and second IDU based on the second operating mode and second command signal, e.g., to provide heating pursuant to a temperature set point (e.g., one or more temperature set points corresponding to each second IDU). Setting and permitting operation of the ODU in the second operating mode inhibits operation of the ODU in the first operating mode. As such, step 1040 may include inhibiting operation of the ODU and first IDU in the first operating mode.

[0039] Method 1000 includes at 1045 operating the ODU and the second IDU in the second operating mode based on the second command signal (e.g., at 1030) after inhibiting or determining non-operation of the ODU and first IDU in the first operating mode. In some embodiments, step 1045 includes operating the ODU and the second IDU for a predetermined period of time in which a time-limit is provided after which the second operation is stopped without regard for whether the temperature set point is achieved. Stated differently, the predetermined period of time provides a time range within which the second operation is to achieve the temperature set point before the ODU and second IDU cease the second operation.

[0040] In some embodiments, the time-limits or time-ranges may differ relative to the first and second operations. For instance, the predetermined period of time may differ based on a quantity of IDUs calling for the first operating mode (e.g., quantity of first IDUs 21) versus a quantity of IDUs calling for the second operating mode (e.g., quantity of first IDUs 22).

[0041] In still some embodiments, the first IDU, first operating mode, and first operation may correspond to a first duty cycle rate greater than a second duty cycle rate corresponding to the second IDU, second operating mode, and second operation. For instance, during cold-weather periods (e.g., winter), the first duty cycle rate may correspond to a heating operation as the majority or greater operation versus a cooling operation. In another instance, during warm-weather periods (e.g., summer), the first duty cycle rate may correspond to a cooling operation as the majority or greater operation versus a heating operation.

[0042] In various embodiments, method 1000 includes one or more iterations of steps permitting the first operation and inhibiting the second operation, and permitting the second operation and inhibiting the first operation.

[0043] In some embodiments, method 1000 may provide prioritization of the second command signal and operation of the second IDU over the first command signal and operation of the first IDUs based on a temporal proximity from which the command signal is obtained at the ODU. For instance, steps 1010, 1020 may generally correspond to an operating mode set for a longer term without changing the operating mode, while step 1030 may correspond to a shorter term operating mode.

[0044] Referring to FIG. 4, a schematic state diagram 400 depicting transitions between heating, idle, and cooling states of the system 100 is provided. The system 100 may include the plurality of IDUs 20 and ODU 10 set to a heating mode. The IDUs 20 may receive, from a user input, call for cool and heat inactive or deactivation. The system may idle for a period of time before call for cool is active and cooling is provided, such as may correspond to a transition from cold-weather conditions to warm-and hot-weather conditions. The IDUs 20 may receive, from a user input, call for heat and cool inactive or deactivation. The system may idle for a period of time before call for heat is active and heating is provided, such as may correspond to a transition from hot-weather conditions to cool-or cold-weather conditions.

[0045] In an exemplary embodiment of operation of the system 100 and method 1000, a user may set the plurality of IDUs 20 to a first operating mode corresponding to a heating mode during cold-weather months. The cold-weather months may generally include ambient outside temperatures ranging, e.g., below 50 degrees Fahrenheit. Accordingly, the plurality of IDUs 20 are set for similar operation, such as first IDUs 21, in accordance with FIG. 2A. Method 1000 at 1010, 1020, and 1025 receives command signals, permits operation, and performs operations at the ODU and IDUs based on the first operating mode (e.g., heating based on one or more temperature set points).

[0046] However, heatwaves, warm-weather conditions, or other phenomena may result in periods during which the ambient outside temperatures are relatively high, e.g., above 50 degrees Fahrenheit. Additionally, or alternatively, conditions within, or entering, the building at which the system is installed may result in rooms or areas having perceptibly different indoor temperatures. For instance, solar radiation through windows, cooking in a kitchen, or upper floors may receive more heat than other areas of the building, such that a user may desire cooling for the particular area. The user may set one or more of the IDUs to a second operating mode correspond to a cooling mode. Accordingly, the plurality of IDUs 20 changed from the first IDUs 21 in the heating mode to a second IDU 22 in a cooling mode, such as in accordance with FIG. 2B, such as provided at step 1030.

[0047] The system including the ODU and first IDUs set to the heating mode receive, from a second command signal, a mode change to cooling (i.e., the first IDU calling for heating changed to the second IDU calling for cooling). Additionally, or alternatively, a set temperature is lowered, such as to command cooling from the second IDU. The ODU receives the command call for cooling and switches to the cooling mode. In some embodiments, active heating operation becomes time-limited with the command call, such as to prioritize operation of the second IDU to provide cooling. After a period of time, or after the cooling temperature set point is achieved, cooling operation is discontinued and the system switches back to the heating operation.

[0048] In some embodiments, method 1000 includes at 1050 monitoring a duty cycle rate and at 1052 determining whether a duty cycle rate threshold is exceeded within a period of time prior to transmitting the second command signal (step 1030). When the duty cycle rate threshold is exceeded, the corresponding duty cycle may be designated as the first operating mode. For instance, when a duty cycle rate corresponding to a heating operation exceeds the threshold, the heating operation is designated as the first operating mode, and the cooling operation is designated as the second operating mode. Steps for operation based on the second operating mode may include prioritization and time-limits in accordance with the second operating mode described in method 1000.

[0049] Determining a greater or majority duty cycle may avoid confusion as to which operating mode is a majority state (e.g., corresponding to the season or predominate ambient conditions) and which is a more transient state (e.g., corresponding to ambient temperature fluctuations and temperature outliers). Additionally, or alternatively, user confusion and dissatisfaction may be avoided by prioritizing the minority operating mode and limiting a delay, or more expediently changing, from the first operating mode to the second operating mode, such as to address the ambient conditions associated with the transient or outlier state.

[0050] Steps of method 1000 described herein may be stored at one or more controllers 36, 46, external computing devices, network devices, or other computing systems, in whole at a single computing device or as distributed code across a plurality of computing devices. Steps of method 1000 provide operability and performance improvements beyond those of user or manual operation or performance. For instance, determinations of first and second operating mode, or majority and minority operating mode, may be impracticable by a user, or impracticable on a repeated and constant performance basis, or unduly bound to user subjectivity as to which operating mode should or will receive priority.

[0051] Embodiments of the system 100 and method 1000 such as provided herein may provide mixed heating and cooling mode operation for a duct-free split HVAC system having a plurality of indoor units operably connected to a single outdoor unit. The mixed mode operation may facilitate heating and cooling in a manner that may be perceived as parallel heating and cooling operation. Embodiments depicted and described herein may avoid user confusion, unnecessary service calls, and user dissatisfaction that may be associated with non-operation of the system for addressing conditions in a single room or minority of rooms or areas in contrast to a majority of rooms or areas. Still various embodiments of the system 100 and method 1000 are configured to perform steps or operations that improve operation over non-computer or non-controller executed steps or operations (e.g., human inputs, perceptions, and changes), such as facilitating operation perceived as parallel heating and cooling operation from a duct-free split HVAC system.

[0052] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Examples

Embodiment Construction

[0018]Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0019]As used herein, the terms “first,”“second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are...

Claims

1. A split heating, ventilation, and air-conditioning system including a single outdoor unit (ODU) configured to circulate refrigerant to a plurality of indoor units (IDUs) for heat exchange, the system having a controller configured to perform operations, the operations comprising:transmitting, to the ODU, a first command signal from one or more IDUs of the plurality of IDUs, the first command signal corresponding to a first operating mode, wherein a first IDU of the plurality of IDUs corresponds to the first command signal corresponding thereto;setting, at the ODU, the first operating mode based on the first command signal;transmitting, to the ODU, a second command signal from at least one IDU of the plurality of IDUs, and fewer than all IDUs of the plurality of IDUs, and while one or more IDUs of the plurality of IDUs is the first IDU corresponding to the first command signal, the second command signal corresponding to a second operating mode, wherein a second IDU of the plurality of IDUs corresponds to the second command signal corresponding thereto, and wherein the first and second operating mode correspond to either a cooling mode or a heating mode, and wherein the first and second operating mode are dissimilar to one another;setting, at the ODU, the second operating mode based on the second command signal;operating the ODU and the second IDU in the second operating mode based on the second command signal; andpermitting, at the ODU after operating the ODU in the second operating mode, the first operating mode based on the first command signal.

2. The system of claim 1, wherein the first and second command signals comprise a temperature set point, or change thereto.

3. The system of claim 1, wherein setting the first operating mode comprises permitting performance of a first operation at the ODU.

4. The system of claim 3, wherein permitting operation of the ODU in the first operating mode inhibits operation of the ODU in the second operating mode.

5. The system of claim 1, wherein setting the second operating mode comprises permitting performance of a second operation at the ODU.

6. The system of claim 5, wherein permitting operation of the ODU in the second operating mode inhibits operation of the ODU in the first operating mode.

7. The system of claim 1, the operations comprising:performing, at the ODU and one or more of the first IDU, the first operation in the first operating mode based on the first command signal.

8. The system of claim 7, wherein transmitting the second command signal generates a time-limit for remaining operation of the ODU and the first IDU in the first operating mode.

9. The system of claim 1, the operations comprising:monitoring a duty cycle rate corresponding to operation of the ODU; anddetermining whether a duty cycle rate threshold is exceeded within a period of time prior to transmitting the second command signal.

10. The system of claim 9, wherein when the duty cycle rate threshold is exceeded, the corresponding duty cycle is designated as the first operating mode.

11. A computer-implemented method for mixed-mode operation for a duct-free split heating, ventilation, and air-conditioning system including a single outdoor unit (ODU) configured to circulate refrigerant to a plurality of indoor units (IDUs) for heat exchange, the method comprising:transmitting, to the ODU, a first command signal from one or more IDUs of the plurality of IDUs, the first command signal corresponding to a first operating mode, wherein a first IDU of the plurality of IDUs corresponds to the first command signal corresponding thereto;setting, at the ODU, the first operating mode based on the first command signal;transmitting, to the ODU, a second command signal from at least one IDU of the plurality of IDUs, and fewer than all IDUs of the plurality of IDUs, and while one or more IDUs of the plurality of IDUs is the first IDU corresponding to the first command signal, the second command signal corresponding to a second operating mode, wherein a second IDU of the plurality of IDUs corresponds to the second command signal corresponding thereto, and wherein the first and second operating mode correspond to either a cooling mode or a heating mode, and wherein the first and second operating mode are dissimilar to one another;setting, at the ODU, the second operating mode based on the second command signal;operating the ODU and the second IDU in the second operating mode based on the second command signal; andpermitting, at the ODU after operating the ODU in the second operating mode, the first operating mode based on the first command signal.

12. The method of claim 11, wherein the first and second command signals comprise a temperature set point, or change thereto.

13. The method of claim 11, wherein setting the first operating mode comprises permitting performance of a first operation at the ODU.

14. The method of claim 13, wherein permitting operation of the ODU in the first operating mode inhibits operation of the ODU in the second operating mode.

15. The method of claim 11, wherein setting the second operating mode comprises permitting performance of a second operation at the ODU.

16. The method of claim 15, wherein permitting operation of the ODU in the second operating mode inhibits operation of the ODU in the first operating mode.

17. The method of claim 11, the operations comprising:performing, at the ODU and one or more of the first IDU, the first operation in the first operating mode based on the first command signal.

18. The method of claim 17, wherein transmitting the second command signal generates a time-limit for remaining operation of the ODU and the first IDU in the first operating mode.

19. The method of claim 11, the operations comprising:monitoring a duty cycle rate corresponding to operation of the ODU; anddetermining whether a duty cycle rate threshold is exceeded within a period of time prior to transmitting the second command signal.

20. The method of claim 19, wherein when the duty cycle rate threshold is exceeded, the corresponding duty cycle is designated as the first operating mode.

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