Systems and methods for heat pump systems with energy recovery

Abstract

Systems and methods for heat pumps with energy recovery systems for selectively heating water and provided. The heat pump system may include an outdoor air heat exchanger, a compressor, an expansion valve, solenoid valves for selectively restricting or permitting refrigerant flow, and a liquid heat exchanger (e.g., water cooled condenser) for recovering energy from the refrigerant to heat water. The liquid heat exchanger may be connected to one or more water heaters for heating water using the energy recovered. The heat pump system may include valves for selectively transitioning the system between a cooling mode with water heating mode, a cooling mode without water heating, and a heating mode.

Description

SYSTEMS AND METHODS FOR HEAT PUMP SYSTEMS WITH ENERGY RECOVERY CROSS-REFERENCE TO RELATED APPLICATIONS

[01] This application claims priority to and benefit of U.S. provisional patent application no. 63 / 616,283 filed December 29, 2023, and U.S. provisional patent application no. 63 / 682,862 filed August 14, 2024, which are both herein incorporated by reference. TECHNICAL FIELD

[01] The present disclosure is generally in the field of heat pump systems. For example, systems and methods are provided herein for heat pumps with air cooled and water cooled condensers.  BACKGROUND

[02] Heat pump systems conveniently and efficiently heat and cool fluids for residential and commercial use. Heat pump systems with reversing valves are often employed in such heating systems. Heat pump systems fitted with a reversing valve can selectively provide heat to a given space (e.g., indoor space) and cool the same space, depending on the direction of the valve. For example, a heat pump system may include indoor coils and outdoor coils. When the reversing valve is in a first direction, the heat pump system may have the indoor coil (e.g., situated within a residential or commercial building) heat the indoor space. When desirable, the reversing valve may be actuated to transition to a second direction to cause the heat pump system move the fluid in a reverse direction to cause the heat pump system to cool the indoor space.

[03] Heat pump water pumps have also been developed to heat water for commercial and / or residential use. The heat pump may use a heat exchanger, which may be an outdoor unit, as well as a compressor and an expansion valve may cause heated refrigerant to enter a water cooled condenser for thermal energy exchange between the heated refrigerant and the cooler water, thereby heating the water and cooling the refrigerant. The cooled refrigerant may then be passed through the expansion valve and the evaporator.

[04] In conventional heat pump systems, when operating in cooling mode, a substantial amount of energy is lost as the refrigerant enters the condenser coil of the heat exchanger as typically a fan is powered to move air over the coil, which requires energy to power the fan.  BRIEF DESCRIPTION OF THE DRAWINGS

[05] FIG. 1 is an illustration of an exemplary heat pump system with an energy recovery system for heating water.

[06] FIG. 2A-2E are schematic illustrations of a heat pump system with an energy recovery system for heating water in cooling mode, cooling mode without energy recovery, and heating mode.

[07] FIG. 3 illustrates an exemplary process flow for selectively directing refrigerant to the liquid heat exchanger for heating water using energy recovery.

[08] FIG. 4 is a schematic block diagram of a controller for a heat pump system with an energy recovery system for heating water.

[09] FIGS. 5A-5B depict various functionality for example heat pump systems having different capacities as shown and described herein. DETAILED DESCRIPTION

[010] It may be desirable to improve energy use of the heat pump system. It further may be desirable to have a heat pump system for both cooling and heating, as well as water heating purposes. Accordingly, there is a need for improved methods and systems for more efficient heat pump systems with cooling, heating, and water heating capabilities.

[011] Improved heat pump systems and controls have been developed with energy recovery systems for selectively heating water. The heat pump system may include an outdoor air heat exchanger, an indoor air heat exchanger, a compressor, an expansion valve, solenoid valves for selectively restricting or permitting refrigerant flow, and a liquid heat exchanger (e.g., water cooled condenser) for recovering energy from the refrigerant to heat water. The liquid heat exchanger may be connected to one or more water heaters for heating water using the energy recovered from the refrigerant.

[012] Referring now to FIG. 1, a heat pump system having energy recovery for water heating is illustrated in a residential setting. As shown in FIG. 1, heat pump system 100 may include outdoor unit 102, liquid heat exchanger 110, and indoor heat exchanger 116. In one example, liquid heat exchanger 110 may be a water cooled condenser. Heat pump system 100 may further include controller 118 and / or water tank 112. In one example, a pump may be positioned between water tank 112 and indoor heat exchanger 110 for circulating water. Heat pump system may optionally include other components such as additional heat exchangers, additional water tanks, additional liquid heat exchangers, valves, sensors, and the like. Heat pump system 100 may be a variable refrigerant flow (VRF) system such that heat pump system 100 may continually adjust the flow of the refrigerant to the various heat exchangers to selectively provide heating, cooling, and / or water heating.

[013] Indoor heat exchanger 116 may be any suitable heat exchanger having a series of coils for receiving a refrigerant and exchanging thermal energy with the surrounding environment via the series of coils. In a cooling mode of operation, the indoor heat exchanger 116 may be an evaporator. In a heating mode of operation, the indoor heat exchanger 116 may be an air cooled condenser. In one example, indoor heat exchanger 116 may be one or more of any type of indoor heat exchanging unit (e.g., a wall mounted unit, ductless head unit, ducted unit, cassette unit, air handling unit (AHU), fresh air handling unit (FAHU), etc.). Indoor heat exchanger 116 may include one or more fans for providing forced convection by enhancing air flow over the series of coils. As shown in FIG. 1, indoor heat exchanger 116 may be positioned within structure 101, which may be a residential or commercial structure and may optionally be connected to ducting for distributing heated or cooled air throughout the structure.

[014] While the example of FIG.1 includes a single indoor heat exchanger 116, in various implementations, multiple indoor heat exchangers may be distributed throughout the structure 101.

[015] Outdoor heat exchanger 104 may be positioned in an outdoor unit 102 and may be connected via tubing with indoor heat exchanger 116 (or a plurality of indoor heat exchangers in parallel) and liquid heat exchanger 110, which may be a water cooled condenser. Outdoor heat exchanger 104 may be the same as or similar to indoor heat exchanger 116 and may be any suitable heat exchanger having a series of coils for receiving a refrigerant and exchanging thermal energy with the surrounding environment via the series of coils and may include one or more fans (e.g., fan 108). In a cooling mode of operation, the outdoor heat exchanger 104 may be an air cooled condenser. In a heating mode of operation, the outdoor heat exchanger 104 may be an evaporator.

[016] Outdoor unit 102 may include a housing with ventilation (e.g., openings, grills, through-holes, etc.). Outdoor unit 102 may house outdoor heat exchanger 104 as well as fan 108 and outdoor components 106, which may include other components of heat pump system 100 such as a compressor, an expansion valve, solenoid or other valves which may be actuated to transition between positions (e.g., open and closed positions or states), service valves, reversing valves, check valves, sensors, and any other suitable heat pump components.

[017] Liquid heat exchanger 110 may be any suitable water cooled condenser or water or liquid cooled heat exchanger. For example, liquid heat exchanger 110 may be a double piped heat exchanger. Alternatively, other suitable water cooled heat exchangers may be used such as shell and tube heat exchangers or any other suitable heat exchanger. In another example, the tubing (e.g., piping) may positioned (e.g., wrapped) around the water tank 112 and / or even immersed within the water tank 112. While only one water tank is illustrated in FIG. 1, multiple water tanks may be used and / or may be connected to one another. In one example, water tanks may be in fluid communication such that desired temperatures in each tank may be achieved by selectively distributing heated water between the tanks. For example, each water heater may have a different set point and / or different demand patterns. In such an arrangement, a mixing valve may be used at each unit to set the temperature of the hot water at each unit individually.

[018] Water tank 112 may be any suitable water tank such as a water heating tank that may hold a certain volume of water and may supply heated water through structure 101 or any other structure (e.g., residential or commercial structure). As such, the water tank 112 includes one a hot water outlet coupled to a hot water circuit for supplying hot water to one or more fixtured within the structure 101 (not shown). The water tank 112 additionally includes a cold water inlet (not shown), such as a municipal water supply, for supplying makeup water to the water tank 112 as hot water is drawn from the water tank 112. In one example, water tank 112 may include one or more electrical heating elements for heating the water in the water tank 112 as a supplement to the liquid heat exchanger 110, such as during times of peak demand. In some implementations, the water tank 112 does not include any electrical heating elements or other supplemental heat. Water tank 112 may further include controller 114 which may be any suitable computing device with a processor and may be in wireless communication with controller 118. Controller 114 may include and / or may be in wired or wireless communication with one or more temperature sensors for determining the temperature of water in water tank 112 and / or sensors for determining a volume of water and / or water demand.

[019] Controller 118 may be any suitable computing device with one or more processors and may optionally include a display. Controller 118 may be in wired or wireless communication with one or more solenoid, four-way, or other valves capable of actuation in outdoor unit 102. In one example, controller 118 may be a thermostat and may oversee both cooling and heating in structure 101 as well as water heating. In such implementations, the controller 118 may be positioned within the structure. In some implementations, the controller 118 may additionally be in communication with one or more additional thermostats in different zones of the structure 101. Controller 118 may also communicate with controller 114 to monitor and / or manage water demand. Controller 118 may communicate with controller 114, liquid heat exchanger 110, various sensors, various valves, and / or components 106. In an example, the outdoor unit 102 may additionally include a controller (not shown) for controlling the fan 108 and components 106. The controller of the outdoor unit 102 may be in communication with controller 118. In some implementations, the controller 118 may be positioned within the outdoor unit 102. In such implementations, the controller 118 may be in communication with one or more thermostats in corresponding one or more zones of the structure 101.

[020] Controller 118 may monitor the temperature of water in water tank 112 and may determine that the water temperature is low (e.g., below a certain threshold value). In response, controller 118 may cause valves in components 106 to open, close, and / or reverse to cause heated refrigerant to move through liquid heat exchanger 110 and to bypass outdoor heat exchanger 104. Controller 118 may further turn off or otherwise adjust the fan of outdoor unit 102 to save energy while refrigerant is directed to liquid heat exchanger 110.

[021] In this manner, using liquid heat exchanger 110 to recover heat from the refrigerant to heat the water in water tank 112, heat pump system 100 may achieve energy recovery. Additional power savings and efficiency may result from fan 108 being reduced or otherwise powered off during water heating. Also, if water tank 112 includes an electrical heating system, the electrical load on such system may be reduced by the energy recovered from the refrigerant. The term cooling mode with water heating or liquid heat exchanger mode refers to the refrigerant being directed to liquid heat exchanger 110.

[022] Controller 118 may also determine that the temperature of water in water tank 112 is too high or exceeds a threshold value. In this case, valves in components 106 of outdoor unit 102 may be adjusted, actuated, and / or reversed to cause refrigerant to no longer flow through liquid heat exchanger 110 and may be caused to traverse outdoor heat exchanger 104. Additionally, fan 108 may be adjusted (e.g., increased speed) or powered on. For example, the valves may be actuated and the fan may be powered on / off based on temperature measurements of the refrigerant returning from the water cooled condenser.

[023] The heat pump system 100 (or any other heat pump system described herein with reference to any of the other figures) may also operate in one of several different modes (which may also be referred to as “modes of operation” herein). Reference is made below to specific threshold temperature values, however, these values are merely exemplary and other values may also be used for any of these thresholds. Additionally, any reference to determining that a temperature is above a threshold, below a threshold, etc. is not intended to be limiting and the determination may also be whether a value is less than or equal to or greater than or equal to a threshold value in some instances as well.

[024] In a first mode (a “high efficiency mode”), the heat from the refrigerant alone may be used to heat the water in the water tank 112 up to a first threshold temperature to save energy (that is, the water may be heated using the energy recovered from the refrigerant loop without relying on the electric heating elements (or singular heating element) of the water tank 112). For example, the first threshold may be 55 degrees Celsius. In this mode, the heat pump system 100 may be adjusted to allow refrigerant to flow between the refrigerant loop including the indoor heat exchanger 116 and the outdoor heat exchanger 104 and the liquid heat exchanger 110 (for example, using certain valves as is described in further detail with respect to FIGS. 2A-2E). In this mode, the electrical heating elements of the water tank 112 may be disabled.

[025] In a second mode (a “standard efficiency mode”), the recovered energy from the refrigerant loop alone may be used to heat the water in the water tank 112 up to a second threshold temperature. However, when the temperature of the water in the water tank 112 is between the second threshold and a third threshold (which may also be inclusive of the second threshold and / or the third threshold or may only include the values between the thresholds), the electrical heating elements of the water tank 112 may be enabled to heat the water in the water tank 112 in combination with the heat from the refrigerant (that is, the electrical heating elements of the water tank 112 are enabled to supplement the heating caused by the recovered energy from the refrigerant loop). Further, when the temperature of the water in the water tank 112 is greater than a fourth threshold, then the water in the water tank 112 may be heated using only the electrical heating elements of the water tank 112 (that is, the water is heated using the electrical heating elements instead of the recovered energy from the refrigerant loop). For example, the second threshold may be 45 degrees Celsius, the third threshold may be 55 degrees Celsius, and the fourth threshold may be 55 degrees Celsius.

[026] In a third mode (a “quick heating mode”), the electrical heating elements of the water tank 112 may be used to heat the water in the water tank 112 in combination with the heat from the refrigerant regardless of the temperature of the water in the water tank 112 (in contrast with the second mode of operation where the energy recovered and the electrical heating elements are used individually or in combination depending on the temperature of the water). In this mode, the heat pump system 100 may be adjusted to prevent refrigerant from flowing between the refrigerant loop including the indoor heat exchanger 116 and the outdoor heat exchanger 104 and the liquid heat exchanger 110 (for example, using certain valves as is described in further detail with respect to FIGS. 2A-2E). This third mode sacrifices the efficiency of the heat pump system 100 in favor of quickly heating the water in the water tank 100 (for example, if a user has an immediate need for hot water that temporarily supersedes the desire for the efficiency of the heat pump system 100).

[027] The heat pump system 100 may, in one or more embodiments, perform certain actions in accordance with the different modes mentioned above based on certain conditions. For example, if the condensing temperature is above a first threshold temperature (which may be 55 degrees Celsius or any other temperature) in any condition, then the heat recovery function may be disabled. If the saturation temperature is below a second threshold temperature (which may be 45 degrees Celsius or any other temperature) in the standard mode, then the heating elements of the water tank 112 may be used to heat the water in the water tank 112 in combination with the heat from the refrigerant. If the temperature set point remains lower than the second threshold for a threshold period of time, then the heat pump system 100 may operate in the standard mode. If the ambient temperature is lower than a third threshold (which may be 35 degrees Celsius or any other temperature) and the temperature of the water in the water tank 112 is below a fourth threshold (which may be 45 degrees Celsius or any other temperature), then the heating elements of the water tank 112 may be used to heat the water in the water tank 112 in combination with the heat from the refrigerant. The condenser fan may run at a minimum speed to maintain the condensing temperature.

[028] The mode of the heat pump system 100 at any given time may be based on a manual user selection. For example, the user may select the mode via the controller 118, however, the user may also manually select the mode via any other suitable device. The selection may be made at the location of the heat pump system 100 (for example, at the structure 101) or may be made from a remote location from the heat pump system 100. For example, the user may make the selection via a smartphone application (as one non-limiting example). Additionally, the mode does not necessarily need to be selected manually. In some instances, the heat pump system 100 (or another system, device, etc.) may automatically select a particular mode based on certain conditions. The controller 118 may be responsible for transitioning the heat pump system 100 between the various modes. For example, the controller 118 may open and / or close certain valves to allow refrigerant to flow between the refrigerant loop including the indoor heat exchanger 116 and the outdoor heat exchanger 104 and the liquid heat exchanger 110.

[029] Referring now to FIGS. 2A-2C, schematic illustrations of a heat pump system with an energy recovery system for heating water in cooling mode , having cooling mode without energy recovery (i.e., without water heating) and a heating mode are illustrated. Heat pump system 200 may be the same as or similar to heat pump system 100 of FIG. 1. For example, heat pump system 200 may include outdoor unit 202 which may include outdoor heat exchanger 204, which may be the same as or similar to outdoor heat exchanger 104 of FIG. 1. Additionally, indoor heat exchanger 216, liquid heat exchanger 210, water tank 212, and controller 218, may be the same as or similar to indoor heat exchanger 116, liquid heat exchanger 110, water tank 112, and controller 118 of FIG. 1, respectively. Liquid heat exchanger 210 may be a water cooled condenser.

[030] Water tank 212 may further include temperature sensor 230 for determining a temperature reading (e.g., temperature value) of the water in the water tank. While only one temperature sensor is illustrated included on water tank 212, multiple temperature sensors may be used. For example, an upper temperature sensor may be located in an upper region of water tank 212 for determining a temperature reading of water in an upper region of the water tank and a lower temperature sensor may be located in a lower region of water tank 212 for determining a temperature reading of water in a lower region of the water tank. Outdoor unit 202 may further include valve 224, valve 226, expansion valve 232, four-way valve 222, compressor 225, temperature sensor 228, and any other suitable heat pump system components. Heat pump system 200 may further include tubing connecting components of heat pump system 200 and designed to guide a fluid such as a refrigerant throughout heat pump system 200. The refrigerant may be, for example, R-410A, R-32, R-454B, or any other suitable refrigerant.

[031] Expansion valve 232 may be any well-known expansion valve. For example, expansion valve 232 may be any expansion valve that removes pressure from the fluid (e.g., refrigerant) as it travels through the expansion valve to allow expansion of the fluid (e.g., from a liquid to a vapor state). The expansion valve 232 may be a thermostatic expansion valve (TXV) or an electronic expansion valve (EXV). Valves 226 and 224 may be any suitable valves that may be actuated to transition from an open position or state to a closed position or state (e.g., by controller 218). In one example, valves 226 and / or 224 may be two-way solenoid valves.

[032] Four-way valve 222 may be any suitable four-way valve. It is understood that any other reversing valve may be used. Compressor 225 may be any well-known compressor used in heat pumps designed to heat the refrigerant into a heated vapor. Temperature sensor 228 may be any suitable temperature sensor for sensing the temperature of the refrigerant. Temperature sensor 230 may be any suitable sensor for sensing the temperature of the water in water tank 212. For example, temperature sensors 228 and temperature sensor 230 may be a thermocouple, thermistor, thermopile, or any other suitable temperature sensor. Water tank 212 may alternatively, or additionally, include one or more sensors for determining hot water demand. For example, a flow meter may be positioned on a cold water inlet or hot water outlet of the water tank 212 for measuring a flow rate of water through the water tank 112, indicative of usage of hot water by one or more fixtures in the structure 101.

[033] As shown in FIG. 2A, compressor 225 may be fluidly connected to four-way valve 222, valve 224, and valve 226. Valve 224 may also be fluidly connected to liquid heat exchanger 210. Four-way valve may be fluidly connected to valve 226, compressor 225, outdoor heat exchanger 204, and indoor heat exchanger 216. Outdoor heat exchanger 204 may be fluidly connected to four-way valve 222 and expansion valve 232. Expansion valve 232 may also be fluidly connected to indoor heat exchanger 216. Indoor heat exchanger may be fluidly connected to expansion valve 232 and four-way valve 222. Liquid heat exchanger 210 may be fluidly connected to tubing connecting outdoor heat exchanger 204 and expansion valve 232, as well as valve 224. Liquid heat exchanger 210 may also be thermally connected to water tank 212. Tubing may position connected components of heat pump system 200 in fluid communication with one another.

[034] Junction 240 may define a point at which tubing extending from liquid heat exchanger 210 connects to tubing connecting outdoor heat exchanger 204 and expansion valve 232. In one example, a one-way valve or check valve may be used to guide fluid from liquid heat exchanger 210 to expansion valve 232 and obstruct backflow towards outdoor heat exchanger 204 in liquid heat exchanger mode. In another example, a solenoid valve such as a three-way solenoid valve may be used to guide such fluid toward expansion valve 232 and away from outdoor heat exchanger 204 in liquid heat exchanger mode. Liquid heat exchanger 210 may be a water cooled condenser.

[035] Referring now to FIG. 2A, refrigerant may be guided through circuit 235 and circuit 239 to heat water in cooling mode with water heating (e.g., liquid heat exchanger mode). For example, circuit 239, which may be a manifold and / or include one or more lengths of tubing, may guide the refrigerant to and from liquid heat exchanger 210. Circuit 235, which may be a manifold and / or include one or more lengths of tubing, may guide the refrigerant to and from indoor heat exchanger 216. In this mode, hot refrigerant (e.g., around 80 to 90 deg. C) is provided to liquid heat exchanger 210 for thermal heat exchange with water of water tank 212 . As the heated refrigerant would otherwise be directed to outdoor heat exchanger 204 and energy dissipated into the ambient environment, redirecting the energy of such heated refrigerant to heat water of water tank 212 permits energy recovery. Additionally, because heated refrigerant is not directed outdoor heat exchanger 204 in heat pump system 200 of FIG. 2A, the fan of outdoor heat exchanger 204 does not need to be powered, thereby providing energy savings.

[036] To achieve cooling mode with water heating in heat pump system 200, illustrated in FIG. 2A, fluid flow (e.g., refrigerant flow) may be directed to bypass the outdoor heat exchanger 204 and flow to liquid heat exchanger 210 by causing (e.g., via commands and / or signals from controller 218) valve 226 to transition to a closed position and valve 224 to transition to an open position. In this configuration, fluid (e.g., refrigerant) will be heated by compressor 225 and be directed through valve 224 to liquid heat exchanger 210, for thermal energy exchange with the water of water tank 212. For example the water may be heated around 5 to 6 degrees C. It is understood that the water may be heated by different values.

[037] The refrigerant will be cooled at liquid heat exchanger 210 and guided towards junction 240 and ultimately expansion valve 232, which will reduce the pressure of the fluid and thus cool the fluid. The fluid will next be directed to indoor heat exchanger 216 for thermal energy exchange with an indoor volume of air for cooling. Refrigerant (e.g., in gaseous form) will be directed from indoor heat exchanger 216 to four-way valve 222 and ultimately back to compressor 225 for heating.

[038] As shown in FIG 2A, temperature sensors 228 and / or 230 may be used to determine temperature values and controller 218 may determine when the water in water tank no longer needs to be heated. In one example, the temperature sensed by temperature sensor 230 may be compared to a threshold value, such as a set point temperature for water tank 212 or an offset from the set point temperature. If it is determined that the sensed temperature exceeds the threshold value a determination is made that water heating in water tank 212 is no longer needed. When controller 218 determines to stop heating the water in the water tank, valve 226 may be transitioned from the closed position to the open position and valve 224 may be transitioned from the open position to the closed position to achieve cooling mode without water heating shown in FIG. 2B.

[039] As shown in FIG. 2B, valve 226 is in the open position and valve 224 is in the closed position. As a result, refrigerant no longer flows to liquid heat exchanger 210. Instead, fluid (e.g., refrigerant) may be heated by compressor 225 and directed through valve 226 to four-way valve 222 and ultimately to outdoor heat exchanger 204 to exchange thermal energy with air in the ambient environment and cool the fluid. Flow may then be directed from outdoor heat exchanger 204 to expansion valve 232 which will further reduce the temperature of the fluid.

[040] The cooled fluid will then be directed to indoor heat exchanger 216 for thermal energy exchange with the indoor environment for cooling, thereby increasing the temperature of the fluid. The fluid may then be directed to four-way wave 222 and ultimately back to compressor 225.

[041] Referring now to FIG. 2C, heat pump system may be transitioned to heating mode to heat an interior environment via indoor heat exchanger 216. To transition heat pump system 200 to heating mode, valve 224 may be closed and valve 226 may be opened (e.g., via controller 218). Further four-way valve 222 may be reversed to provide fluid communication between outdoor heat exchanger 204 and valve 226 as well as fluid communication between indoor heat exchanger 216 and compressor 225.

[042] As shown in FIG. 2C, fluid may be heated by compressor 225 and guided through four-way valve to indoor heat exchanger 216 to exchange thermal energy with the indoor environment. The fluid may then be directed through expansion valve 232 to reduce pressure and temperature of the fluid and then to outdoor heat exchanger 204 to exchange thermal energy with the outdoor environment. From outdoor heat exchanger 204 fluid may be directed back to compressor through four-way valve 222 and valve 226. As shown in FIG. 2C, liquid heat exchanger 210 may be bypassed. Referring now to FIG. 2D, an alternative heat pump system with an energy recovery system for heating water in cooling mode and having cooling mode without energy recovery (i.e., without water heating) as well as a heating mode are illustrated. Heat pump system 250 may be the substantially the same as same heat pump system 200 of FIGS. 2A-2C, but with multiple indoor heat exchangers and with expansion valves 253, 254, 255, and 256. As shown in FIG. 2D, heat pump system 250 may be an a variable refrigerant flow (VRF) system. For example, heat pump system 250 may include indoor heat exchangers 252 and 251, which each may be the same as or similar to indoor heat exchanger 216 of FIGS. 2A-2C. While two indoor heat exchangers are illustrated in FIG. 2D, more than two indoor heat exchangers may be used. Expansion valves 253, 254, 255 and / or 256 may be the same as or similar to expansion valve 235 of FIG. 2A-2C.

[043] Similar to heat pump system 200 of FIG. 2A, refrigerant may be guided through circuit 235 and circuit 239 to heat water in cooling mode with water heating. For example, circuit 239 may guide the refrigerant to and from liquid heat exchanger 210. Circuit 235, which includes one or more lengths of tubing, may guide the refrigerant to and from indoor heat exchangers 252 and 251. In this mode, hot refrigerant (e.g., around 80 to 90 deg. C) is provided to liquid heat exchanger 210 for thermal heat exchange with water of water tank 212 . As the heated refrigerant would otherwise be directed to outdoor heat exchanger 204 and energy dissipated into the ambient environment, redirecting the energy of such heated refrigerant to heat water of water tank 212 permits energy recovery. Additionally, because heated refrigerant is not directed outdoor heat exchanger 204 in heat pump system 200 of FIG. 2A, the fan of outdoor heat exchanger 204 does not need to be powered, thereby providing energy savings.

[044] To achieve cooling mode with water heating in heat pump system 250, illustrated in FIG. 2D, fluid flow (e.g., refrigerant flow) may be directed to bypass the outdoor heat exchanger 204 and flow to liquid heat exchanger 210 by causing (e.g., via commands and / or signals from controller 218) valve 226 to transition to a closed position and valve 224 to transition to an open position. In this configuration, refrigerant will be heated by compressor 225 and be directed through valve 224 to liquid heat exchanger 210, for thermal energy exchange with the water of water tank 212. The refrigerant will be cooled at liquid heat exchanger 210 and guided through expansion valve 255 and then towards junction 240 and ultimately expansion valves 253 and 254, which will reduce the pressure of the refrigerant and thus cool the refrigerant prior to being directed into indoor heat exchangers 252 and 251, respectively. For example, expansion valve 253 may be positioned in an indoor unit with indoor heat exchanger 252 and expansion valve 254 may be positioned in an indoor unit with indoor heat exchanger 251. Refrigerant (e.g., in gaseous form) will be directed from indoor heat exchangers 251 and 252 to four-way valve 222 and ultimately back to compressor 225 for heating. Liquid heat exchanger 210 may include expansion valve 255 in the same unit or housing as liquid heat exchanger 210 or otherwise integrate expansion valve 255 into liquid heat exchanger 210

[045] Similar to heat pump system 200 of FIG. 2B, in heat pump system 250 valve 226 may be transitioned to the open position and valve 224 transitioned to the closed position to bypass liquid heat exchanger 210. Also, similar to heat pump system 200 of FIG. 2C, heat pump system 250 may be transitioned to heating mode to heat an interior environment via indoor heat exchangers 251 and 251. For example, valve 224 may be closed and valve 226 may be opened. Further four-way valve 222 may be reversed to provide fluid communication between outdoor heat exchanger 204 and valve 226 as well as fluid communication between indoor heat exchangers 251 and 252 and compressor 225. In heating mode, heat exchanger 204 may be in refrigerant communication with expansion valve 256.

[046] Referring now to FIG. 2E, alternative heat pump system 203 is illustrated. Heat pump system 203 may the same as heat pump system 200 of FIG. 2A in every way except that valves 224 and 226 may be removed and replaced with valve 227 which may be a three-way solenoid valve in communication with and actuated by controller 218. Three-way solenoid valve 227 may be positioned at the junction between the tubing extending between compressor 225 and liquid heat exchanger 210 as well as four-way valve 222. Three-way solenoid valve may be used to selectively bypass outdoor heat exchanger 204 in cooling mode with water heating and bypass liquid heat exchanger 210 when controller 218 determines to no longer heat the water in the water tank, similar to heat pump system 200 of FIG. 2A.

[047] Referring now to FIG. 3, an example process flow 300 for actuating valves to transition a heat pump system to a cooling mode with water heating (e.g., for energy recovery) and to a cooling mode without water heating (i.e., without energy recovery). The heat pump system in process flow 300 may be the same or similar to heat pump system 200 of FIGS. 2A-2B and the controller may be the same as or similar to controller 218 of FIGS. 2A-2B..

[048] While example embodiments of the disclosure may be described in the context of a controller, it should be appreciated that the disclosure is more broadly applicable to various types of computing devices as well as a controller in combination with a computing device, such as a server. Some or all of the blocks of the process flows in this disclosure may be performed in a distributed manner across any number of devices. The operations of process flow 300 may be optional and may be performed in a different order.

[049] At block 302, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to determine a temperature value corresponding to the temperature of water in the water tank. The water tank (e.g., via a controller on the water tank) may periodically send temperature values to the controller and / or the controller may request such values.

[050] At decision 304, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to determine whether the temperature value is above a lower threshold value. For example, a desirable temperature range for water in the heat pump may be determined or otherwise identified and the lower threshold value may be the smaller value in the range. If the temperature value is above or equal to the lower threshold value, then at block 306 computer-executable instructions stored on a memory of a device, such as a controller, may be executed to determine to maintain the current heat pump settings (e.g., no change in the heat pump operation may be necessary) and block 302 may be reinitiated (e.g., after a set period of time). Alternatively, if the temperature value is not above or equal to the lower threshold value (e.g., the temperature value may lower than the threshold setting), then block 308 may be initiated.

[051] At block 308, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to determine to transition the pump to a liquid heat exchanger mode (e.g., cooling mode with water heating). At block 310, At computer-executable instructions stored on a memory of a device, such as a controller, may be executed to cause a first valve to transition to an open position to place the compressor in fluid communication with the liquid heat exchanger (e.g., water cooled condenser). For example, the first valve may be valve 224 in FIG. 2A. If valve 224 is already open, then block 310 may be skipped.

[052] At block 312, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to determine to cause a second valve to transition to a closed position to restrict fluid flow between the compressor and the four-way valve. For example, the second valve may be valve 226 in FIG. 2A. If valve 226 is already closed, then block 312 may be skipped. At block 314, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to determine to run the heat pump system in the cooling mode with water heating.

[053] At block 315, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to once again determine a temperature value corresponding to the water tank after running the heat pump system in cooling mode water heating at block 315. At decision 319, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to determine whether the temperature value is below an upper threshold value.

[054] If the first temperature value is below or equal to the upper threshold value (e.g., the temperature value is within the desired range), at block 317 computer-executable instructions stored on a memory of a device, such as a controller, may be executed to maintain the pump settings and block 314 may be reinitiated to continue to run the heat pump system in cooling mode with water heating. Alternatively, if the first temperature value is above the upper threshold value (e.g., the temperature value is larger than the desired range), block 316 may be initiated.

[055] At block 316, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to cause the cause the first valve to transition to a closed position to restrict fluid flow between the compressor and the liquid heat exchanger. At block 318, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to cause the second valve to transition to an open position to permit fluid flow between the compressor and the outdoor heat exchanger. At block 320, computer-executable instructions stored on a memory of a device, such as a controller, may be executed to run the heat pump in a cooling without water heating mode (e.g., bypassing the liquid heat exchanger). After block 320, block 302 may be reinitiated.

[056] FIG. 4 is a schematic block diagram of controller 400, in accordance with one or more example embodiments of the disclosure. Controller 400 may be the same as controller 118 of FIG. 1. While the schematic block diagram is described with respect to controller 400, it is understood that other controllers, servers, and / or computing devices may additionally or alternatively be used.

[057] Controller 400 may be configured to communicate with one or more servers, computing devices, controllers, user devices, other systems, or the like. Controller 400 may be configured to communicate via one or more networks. Such network(s) may include, but are not limited to, any one or more different types of communications networks such as, for example, cable networks, public networks (e.g., the Internet), private networks (e.g., frame-relay networks), wireless networks, cellular networks, telephone networks (e.g., a public switched telephone network), or any other suitable private or public packet-switched or circuit-switched networks.

[058] In an illustrative configuration, controller 400 may include one or more processors 402, one or more memory devices 404 (also referred to herein as memory 404), one or more input / output (I / O) interface(s) 406, one or more network interface(s) 408, one or more transceiver(s) 410, one or more antenna(s) 434, and data storage 420. The controller 400 may further include one or more bus(es) 418 that functionally couple various components of the controller 400.

[059] The bus(es) 418 may include at least one of a system bus, a memory bus, an address bus, or a message bus, and may permit exchange of information (e.g., data (including computer-executable code), signaling, etc.) between various components of the controller 400. The bus(es) 418 may include, without limitation, a memory bus or a memory controller, a peripheral bus, an accelerated graphics port, and so forth. The bus(es) 418 may be associated with any suitable bus architecture.

[060] The memory 404 may include volatile memory (memory that maintains its state when supplied with power) such as random access memory (RAM) and / or non-volatile memory (memory that maintains its state even when not supplied with power) such as read-only memory (ROM), flash memory, ferroelectric RAM (FRAM), and so forth. Persistent data storage, as that term is used herein, may include non-volatile memory. In various implementations, the memory 404 may include multiple different types of memory such as various types of static random access memory (SRAM), various types of dynamic random access memory (DRAM), various types of unalterable ROM, and / or writeable variants of ROM such as electrically erasable programmable read-only memory (EEPROM), flash memory, and so forth.

[061] The data storage 420 may include removable storage and / or non-removable storage including, but not limited to, magnetic storage, optical disk storage, and / or tape storage. The data storage 420 may provide non-volatile storage of computer-executable instructions and other data. The memory 404 and the data storage 420, removable and / or non-removable, are examples of computer-readable storage media (CRSM) as that term is used herein. The data storage 420 may store computer-executable code, instructions, or the like that may be loadable into the memory 404 and executable by the processor(s) 402 to cause the processor(s) 402 to perform or initiate various operations. The data storage 420 may additionally store data that may be copied to memory 404 for use by the processor(s) 402 during the execution of the computer-executable instructions. Moreover, output data generated as a result of execution of the computer-executable instructions by the processor(s) 402 may be stored initially in memory 404, and may ultimately be copied to data storage 420 for non-volatile storage.

[062] The data storage 420 may store one or more operating systems (O / S) 422; one or more optional database management systems (DBMS) 424; and one or more program module(s), applications, engines, computer-executable code, scripts, or the like such as, for example, one or more implementation modules 426, temperature control modules 427, operational modules 429, and one or more communication modules 428. Some or all of these modules may be sub-modules. Any of the components depicted as being stored in data storage 420 may include any combination of software, firmware, and / or hardware. The software and / or firmware may include computer-executable code, instructions, or the like that may be loaded into the memory 404 for execution by one or more of the processor(s) 402. Any of the components depicted as being stored in data storage 420 may support functionality described in reference to correspondingly named components earlier in this disclosure.

[063] Referring now to other illustrative components depicted as being stored in the data storage 420, the O / S 422 may be loaded from the data storage 420 into the memory 404 and may provide an interface between other application software executing on the controller 400 and hardware resources of the controller 400. More specifically, the O / S 422 may include a set of computer-executable instructions for managing hardware resources of the controller 400 and for providing common services to other application programs (e.g., managing memory allocation among various application programs). In certain example embodiments, the O / S 422 may control execution of the other program module(s) to for content rendering. The O / S 422 may include any operating system now known or which may be developed in the future including, but not limited to, any server operating system, any mainframe operating system, or any other proprietary or non-proprietary operating system.

[064] The optional DBMS 424 may be loaded into the memory 404 and may support functionality for accessing, retrieving, storing, and / or manipulating data stored in the memory 404 and / or data stored in the data storage 420. The DBMS 424 may use any of a variety of database models (e.g., relational model, object model, etc.) and may support any of a variety of query languages. The DBMS 424 may access data represented in one or more data schemas and stored in any suitable data repository including, but not limited to, databases (e.g., relational, object-oriented, etc.), file systems, flat files, distributed datastores in which data is stored on more than one node of a computer network, peer-to-peer network datastores, or the like.

[065] The optional input / output (I / O) interface(s) 406 may facilitate the receipt of input information by the controller 400 from one or more I / O devices as well as the output of information from the controller 400 to the one or more I / O devices. The I / O devices may include any of a variety of components such as a display or display screen having a touch surface or touchscreen; an audio output device for producing sound, such as a speaker; an audio capture device, such as a microphone; an image and / or video capture device, such as a camera; and so forth. Any of these components may be integrated into the controller 400 or may be separate.

[066] The controller 400 may further include one or more network interface(s) 408 via which the con controller 400 may communicate with any of a variety of other systems, platforms, networks, devices, and so forth. The network interface(s) 408 may enable communication, for example, with one or more wireless routers, one or more host servers, one or more web servers, and the like via one or more of networks.

[067] The antenna(s) 434 may include any suitable type of antenna depending, for example, on the communications protocols used to transmit or receive signals via the antenna(s) 434. Non-limiting examples of suitable antennas may include directional antennas, non-directional antennas, dipole antennas, folded dipole antennas, patch antennas, multiple-input multiple-output (MIMO) antennas, or the like. The antenna(s) 434 may be communicatively coupled to one or more transceivers 410 or radio components to which or from which signals may be transmitted or received. Antenna(s) 434 may include, without limitation, a cellular antenna for transmitting or receiving signals to / from a cellular network infrastructure, an antenna for transmitting or receiving Wi-Fi signals to / from an access point (AP), a Global Navigation Satellite System (GNSS) antenna for receiving GNSS signals from a GNSS satellite, a Bluetooth antenna for transmitting or receiving Bluetooth signals including BLE signals, a Near Field Communication (NFC) antenna for transmitting or receiving NFC signals, a 900 MHz antenna, and so forth.

[068] The transceiver(s) 410 may include any suitable radio component(s) for, in cooperation with the antenna(s) 434, transmitting or receiving radio frequency (RF) signals in the bandwidth and / or channels corresponding to the communications protocols utilized by the controller 400 to communicate with other devices. The transceiver(s) 410 may include hardware, software, and / or firmware for modulating, transmitting, or receiving – potentially in cooperation with any of antenna(s) 434 – communications signals according to any of the communications protocols discussed above including, but not limited to, one or more Wi-Fi and / or Wi-Fi direct protocols, as standardized by the IEEE 802.11 standards, one or more non-Wi-Fi protocols, or one or more cellular communications protocols or standards. The transceiver(s) 410 may further include hardware, firmware, or software for receiving GNSS signals. The transceiver(s) 410 may include any known receiver and baseband suitable for communicating via the communications protocols utilized by the controller 400. The transceiver(s) 410 may further include a low noise amplifier (LNA), additional signal amplifiers, an analog-to-digital (A / D) converter, one or more buffers, a digital baseband, or the like.

[069] Referring now to functionality supported by the various program module(s) depicted in FIG. 4, the implementation module(s) 426 may include computer-executable instructions, code, or the like that responsive to execution by one or more of the processor(s) 402 may perform functions including, but not limited to, overseeing coordination and interaction between one or more modules and computer executable instructions in data storage 420, determining user selected actions and tasks, determining actions associated with adjusting heat pump modes (e.g., cooling mode with water heating , cooling mode without water heating, heating mode), and the like.

[070] The temperature control module(s) 427 may include computer-executable instructions, code, or the like that responsive to execution by one or more of the processor(s) 402 may perform functions including, but not limited to, analyzing temperature values, water demand, and predetermined thresholds and / or ranges to determine whether to make adjustments to operation of the heat pump system.

[071] The communication module(s) 428 may include computer-executable instructions, code, or the like that responsive to execution by one or more of the processor(s) 402 may perform functions including, but not limited to, communicating with one or more devices, for example, via wired or wireless communication, communicating with sensors, water heater controllers, heat exchanger controllers, communicating with servers (e.g., remote servers), communicating with remote datastores and / or databases, sending or receiving notifications or commands / directives, communicating with cache memory data, communicating with user devices, and the like.

[072] The operational module(s) 429 may include computer-executable instructions, code, or the like that responsive to execution by one or more of the processor(s) 402 may oversee operation of the heat pump and may perform functions including, but not limited to, actuating reversing valves, three-way valves, solenoid valves, and / or two-way valves to achieve desired fluid flow paths and to open and close certain valves.

[073] Although specific embodiments of the disclosure have been described, one of ordinary skill in the art will recognize that numerous other modifications and alternative embodiments are within the scope of the disclosure. For example, any of the functionality and / or processing capabilities described with respect to a particular device or component may be performed by any other device or component. Further, while various illustrative implementations and architectures have been described in accordance with embodiments of the disclosure, one of ordinary skill in the art will appreciate that numerous other modifications to the illustrative implementations and architectures described herein are also within the scope of this disclosure.

[074] Certain aspects of the disclosure are described above with reference to block and flow diagrams of systems, methods, apparatuses, and / or computer program products according to example embodiments. It will be understood that one or more blocks of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and the flow diagrams, respectively, may be implemented by execution of computer-executable program instructions. Likewise, some blocks of the block diagrams and flow diagrams may not necessarily need to be performed in the order presented, or may not necessarily need to be performed at all, according to some embodiments. Further, additional components and / or operations beyond those depicted in blocks of the block and / or flow diagrams may be present in certain embodiments.

[075] Accordingly, blocks of the block diagrams and flow diagrams support combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions, and program instruction means for performing the specified functions. It will also be understood that each block of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, may be implemented by special-purpose, hardware-based computer systems that perform the specified functions, elements or steps, or combinations of special-purpose hardware and computer instructions.

[076] Program module(s), applications, or the like disclosed herein may include one or more software components, including, for example, software objects, methods, data structures, or the like. Each such software component may include computer-executable instructions that, responsive to execution, cause at least a portion of the functionality described herein (e.g., one or more operations of the illustrative methods described herein) to be performed.

[077] A software component may be coded in any of a variety of programming languages. An illustrative programming language may be a lower-level programming language such as an assembly language associated with a particular hardware architecture and / or operating system platform. A software component comprising assembly language instructions may require conversion into executable machine code by an assembler prior to execution by the hardware architecture and / or platform.

[078] Another example programming language may be a higher-level programming language that may be portable across multiple architectures. A software component comprising higher-level programming language instructions may require conversion to an intermediate representation by an interpreter or a compiler prior to execution.

[079] Other examples of programming languages include, but are not limited to, a macro language, a shell or command language, a job control language, a script language, a database query or search language, or a report writing language. In one or more example embodiments, a software component comprising instructions in one of the foregoing examples of programming languages may be executed directly by an operating system or other software component without having to be first transformed into another form.

[080] A software component may be stored as a file or other data storage construct. Software components of a similar type or functionally related may be stored together such as, for example, in a particular directory, folder, or library. Software components may be static (e.g., pre-established or fixed) or dynamic (e.g., created or modified at the time of execution).

[081] Software components may invoke or be invoked by other software components through any of a wide variety of mechanisms. Invoked or invoking software components may comprise other custom-developed application software, operating system functionality (e.g., device drivers, data storage (e.g., file management) routines, other common routines, and services, etc.), or third-party software components (e.g., middleware, encryption, or other security software, database management software, file transfer or other network communication software, mathematical or statistical software, image processing software, and format translation software).

[082] Software components associated with a particular solution or system may reside and be executed on a single platform or may be distributed across multiple platforms. The multiple platforms may be associated with more than one hardware vendor, underlying chip technology, or operating system. Furthermore, software components associated with a particular solution or system may be initially written in one or more programming languages, but may invoke software components written in another programming language.

[083] Computer-executable program instructions may be loaded onto a special-purpose computer or other particular machine, a processor, or other programmable data processing apparatus to produce a particular machine, such that execution of the instructions on the computer, processor, or other programmable data processing apparatus causes one or more functions or operations specified in the flow diagrams to be performed. These computer program instructions may also be stored in a CRSM that upon execution may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement one or more functions or operations specified in the flow diagrams. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational elements or steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process.

[084] Additional types of CRSM that may be present in any of the devices described herein may include, but are not limited to, programmable random access memory (PRAM), SRAM, DRAM, RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the information and which can be accessed. Combinations of any of the above are also included within the scope of CRSM. Alternatively, computer-readable communication media (CRCM) may include computer-readable instructions, program module(s), or other data transmitted within a data signal, such as a carrier wave, or other transmission. However, as used herein, CRSM does not include CRCM.

[085] FIGS. 5A-5B are tables depicting various functionality for example heat pump systems having different capacities as shown and described herein. Specifically, FIGS. 5A-5B show testing data indicating the efficiency gains resulting from the systems and methods described herein. FIG. 5A presents testing data for a 10HP unit and FIG. 5B presents testing data for a 16HP unit. It should be noted that these values are merely intended to illustrate the efficiency gains and are not intended to be limiting in any way.

[086] Although embodiments have been described in language specific to structural features and / or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments could include, while other embodiments do not include, certain features, elements, and / or steps. Thus, such conditional language is not generally intended to imply that features, elements, and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and / or steps are included or are to be performed in any particular embodiment.

[087] Example Embodiments

[088] Embodiment 1. A heat pump system for recovering energy for water heating. In one or more embodiments, the heat pump system comprises a first heat exchanger configured to receive a refrigerant and exchange thermal energy between the refrigerant and a first volume of air. In one or more embodiments, the heat pump system also comprises a second heat exchanger configured to receive the refrigerant and exchange thermal energy with a second volume of air. In one or more embodiments, the heat pump system also comprises a third heat exchanger configured to receive the refrigerant and exchange thermal energy with a volume of water. In one or more embodiments, the heat pump system also comprises a compressor configured to receive and heat the refrigerant, wherein the compressor is in fluid communication with the first heat exchanger, the second heat exchanger, and the third heat exchanger via a four-way valve. In one or more embodiments, the heat pump system also comprises a first valve in fluid communication with the compressor and the third heat exchanger and configured to transition from an first open state permitting fluid flow through the first valve to a first closed state to restrict fluid flow between the compressor and the third heat exchanger. In one or more embodiments, the heat pump system also comprises a second valve in fluid communication with the compressor and the first heat exchanger and configured to transition from a second open state permitting fluid flow through the second valve to a second closed state to restrict fluid flow between the compressor and the first heat exchanger, wherein the third heat exchanger is configured to recover energy from the refrigerant when the first valve is in the open state and the second valve in the closed state

[089] Embodiment 2. The heat pump system of Embodiment 1, further comprising a first expansion valve in fluid communication with the first heat exchanger, a second expansion valve in fluid communication the second heat exchanger, and a third heat exchanger in fluid communication with the third heat exchanger.

[090] Embodiment 3. The heat pump system of Embodiment 2, further comprising a water tank in fluid communication with the third heat exchanger.

[091] Embodiment 4. The heat pump system of any of Embodiments 1-3, wherein the water tank is configured to provide a volume of water to the third heat exchanger and wherein the third heat exchanger is configured to cause the refrigerant to exchange thermal energy with the volume of water, wherein the third heat exchanger is configured to circulate the refrigerant around a portion of the water tank to cause the refrigerant to exchange thermal energy with the refrigerant, or wherein the third heat exchanger is configured to be partially immersed in the water tank to cause the refrigerant to exchange thermal energy with the refrigerant.

[092] Embodiment 5. The heat pump system of any of Embodiments 1-4, wherein the first valve and the second valve are solenoid valves and are configured to be independently actuated.

[093] Embodiment 6. The heat pump system of any of Embodiments 1-5, wherein the refrigerant moves through the third heat exchanger when the first valve is in the first open state and the second valve is in the second closed state.

[094] Embodiment 7. The heat pump system of any of Embodiments 1-6, wherein the third heat exchanger is a water cooled condenser.

[095] Embodiment 8. The heat pump system of any of Embodiments 1-7, wherein the refrigerant moves through the third heat exchanger when the first valve is in the first open state and the second valve is in the second closed state.

[096] Embodiment 9. The heat pump system of any of Embodiments 1-8, further comprising a controller configured to: control actuation of the first valve, the second valve, and the four-way valve. In one or more embodiments, the controller is further configured to: determine that the heat pump system is in a first mode of operation, wherein the volume of water is heated by the refrigerant without an electrical heating element in the first mode of operation.

[097] Embodiment 10. The heat pump system of any of Embodiments 1-9, wherein the controller is further configured to determine that the temperature of the volume of water is greater than or equal to a first threshold temperature and less than or equal to a second temperature threshold. In one or more embodiments, the controller is further configured to cause an electrical heater to heat the volume of water in combination with the refrigerant. In one or more embodiments, the controller is further configured to determine that the temperature of the volume of water is greater than the second temperature threshold. In one or more embodiments, the controller is further configured to cause the first valve to transition from the first open state to the first closed state to prevent fluid flow through the third heat exchanger such that the volume is water is heated using the electrical heater instead of the third heat exchanger.

[098] Embodiment 11. The heat pump system of any of Embodiments 1-10, wherein the controller is further configured to determine that the heat pump system is in a third mode of operation. In one or more embodiments, the controller is further configured to cause the first valve to transition from the first closed state to the first open state to allow fluid flow through the third heat exchanger such that the volume is water is heated using the electrical heater and the refrigerant in combination.

[099] Embodiment 12. The heat pump system of any of Embodiments 1-11, further comprising a water tank in refrigerant communication with the third heat exchanger and. In one or more embodiments, the heat pump system further comprises a first temperature sensor in fluid communication with an output of the third heat exchanger and configured to generate a temperature value indicative of a temperature of the refrigerant.

[0100] Embodiment 13. The heat pump system of any of Embodiments 1-12, wherein the controller is configured to cause the first valve to transition to the first closed state and the second valve to transition to the second open state if the temperature value exceeds a threshold value.

[0101] Embodiment 14. The heat pump system of any of Embodiments, 1-13, wherein the controller is configured to cause the first valve to transition to the first open state and the second valve to transition to the second closed state if the temperature value is below a threshold value.

[0102] Embodiment 15. A method of recovering energy in a heat pump system for water heating. In one or more embodiments, the method comprises determining to heat water via a liquid heat exchanger, the heat pump system comprising a first air heat exchanger, a second air heat exchanger, the liquid heat exchanger, a compressor, a first valve, a second valve, and an expansion valve, the compressor in fluid communication with the first air heat exchanger, the second air heat exchanger, and the liquid heat exchanger, wherein the first valve is positioned between the compressor and the third liquid heat exchanger, and the second valve is positioned between the compressor and the first air heat exchanger. In one or more embodiments, the method also comprises causing the first valve to transition from a first closed state to a first open state to provide fluid communication between the compressor and the liquid heat exchanger. In one or more embodiments, the method also comprises causing the second valve to transition from a second open state to a second closed state to restrict fluid flow between the compressor and the first air heat exchanger, wherein causing the first valve to transition to the first open state and the second valve to transition to the second closed state causes fluid to flow from the compressor to the liquid heat exchanger, from the liquid heat exchanger to the expansion valve, from the expansion valve to the second air heat exchanger, and from the second air heat exchanger to the compressor.

Claims

1. A heat pump system for recovering energy for water heating, the heat pump system comprising:a first heat exchanger configured to receive a refrigerant and exchange thermal energy between the refrigerant and a first volume of air; a second heat exchanger configured to receive the refrigerant and exchange thermal energy with a second volume of air; a third heat exchanger configured to receive the refrigerant and exchange thermal energy with a volume of water; a compressor configured to receive and heat the refrigerant, wherein the compressor is in fluid communication with the first heat exchanger, the second heat exchanger, and the third heat exchanger via a four-way valve;a first valve in fluid communication with the compressor and the third heat exchanger and configured to transition from a first open state permitting fluid flow through the first valve to a first closed state to restrict fluid flow between the compressor and the third heat exchanger; and a second valve in fluid communication with the compressor and the first heat exchanger and configured to transition from a second open state permitting fluid flow through the second valve to a second closed state to restrict fluid flow between the compressor and the first heat exchanger,wherein the third heat exchanger is configured to recover energy from the refrigerant when the first valve is in the open state and the second valve in the closed state.

2. The heat pump system of claim 1, further comprising a first expansion valve in fluid communication with the first heat exchanger, a second expansion valve in fluid communication the second heat exchanger, and a third expansion valve in fluid communication with the third heat exchanger.

3. The heat pump system of claim 2, further comprising a water tank in fluid communication with the third heat exchanger.

4. The heat pump system of any of claims 1-3, wherein the water tank is configured to provide a volume of water to the third heat exchanger and wherein the third heat exchanger is configured to cause the refrigerant to exchange thermal energy with the volume of water, wherein the third heat exchanger is configured to circulate the refrigerant around a portion of the water tank to cause the refrigerant to exchange thermal energy with the refrigerant, or wherein the third heat exchanger is configured to be partially immersed in the water tank to cause the refrigerant to exchange thermal energy with the refrigerant.

5. The heat pump system of any of claims 1-4, wherein the first valve and the second valve are solenoid valves and are configured to be independently actuated.

6. The heat pump system of any of claims 1-5, wherein the refrigerant moves through the third heat exchanger when the first valve is in the first open state and the second valve is in the second closed state.

7. The heat pump system of any of claims 1-6, wherein the third heat exchanger is a water cooled condenser.

8. The heat pump system of any of claims 1-7, wherein the refrigerant is obstructed from moving through the third heat exchanger when the first valve is in the first closed state and the second valve is in the second open state.

9. The heat pump system of any of claims 1-8, further comprising a controller configured to: control actuation of the first valve, the second valve, and the four-way valve, wherein the controller is further configured to: determine that the heat pump system is in a first mode of operation, wherein the volume of water is heated by the refrigerant without an electrical heating element in the first mode of operation.

10. The heat pump system of any of claims 1-9, wherein the controller is further configured to: determine that the temperature of the volume of water is greater than or equal to a first threshold temperature and less than or equal to a second temperature threshold; cause an electrical heater to heat the volume of water in combination with the refrigerant; determine that the temperature of the volume of water is greater than the second temperature threshold; and cause the first valve to transition from the first open state to the first closed state to prevent fluid flow through the third heat exchanger such that the volume is water is heated using the electrical heater instead of the third heat exchanger.

11. The heat pump system of any of claims 1-10, wherein the controller is further configured to: determine that the heat pump system is in a third mode of operation;cause the first valve to transition from the first closed state to the first open state to allow fluid flow through the third heat exchanger such that the volume is water is heated using the electrical heater and the refrigerant in combination.

12. The heat pump system of any of claims 1-11, further comprising: a water tank in refrigerant communication with the third heat exchanger and; and a first temperature sensor in fluid communication with an output of the third heat exchanger and configured to generate a temperature value indicative of a temperature of the refrigerant.

13. The heat pump system of any of claims 1-12, wherein the controller is configured to cause the first valve to transition to the first closed state and the second valve to transition to the second open state if the temperature value exceeds a threshold value.

14. The heat pump system of any of claims 1-13, wherein the controller is configured to cause the first valve to transition to the first open state and the second valve to transition to the second closed state if the temperature value is below a threshold value.

15. A method of recovering energy in a heat pump system for water heating, the method comprising: determining to heat water via a liquid heat exchanger, the heat pump system comprising a first air heat exchanger, a second air heat exchanger, the liquid heat exchanger, a compressor, a first valve, a second valve, and an expansion valve, the compressor in fluid communication with the first air heat exchanger, the second air heat exchanger, and the liquid heat exchanger, wherein the first valve is positioned between the compressor and the liquid heat exchanger, and the second valve is positioned between the compressor and the first air heat exchanger; causing the first valve to transition from a first closed state to a first open state to provide fluid communication between the compressor and the liquid heat exchanger; and causing the second valve to transition from a second open state to a second closed state to restrict fluid flow between the compressor and the first air heat exchanger, wherein causing the first valve to transition to the first open state and the second valve to transition to the second closed state causes fluid to flow from the compressor to the liquid heat exchanger, from the liquid heat exchanger to the expansion valve, from the expansion valve to the second air heat exchanger, and from the second air heat exchanger to the compressor.  

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