US20170016631A1

US20170016631A1 - Water heater appliance

Info

Publication number: US20170016631A1
Application number: US14/799,958
Authority: US
Inventors: Timothy Scott Shaffer
Original assignee: Haier US Appliance Solutions Inc
Current assignee: Haier US Appliance Solutions Inc
Priority date: 2015-07-15
Filing date: 2015-07-15
Publication date: 2017-01-19

Abstract

Water heater appliances are provided. A water heater appliance includes a tank, a hot water conduit and a cold water conduit. The water heater appliance further includes a heat pump assembly configured to heat water within the chamber of the tank, and a thermo-electric assembly configured to generate an electrical current. The thermo-electric assembly includes a thermo-electric converter, a working fluid flowable through the thermo-electric converter, and a heat source configured to heat the working fluid within the thermo-electric converter. At least a portion of the electrical current generated by the thermo-electric assembly is flowed to the heat pump assembly to at least partially power the heat pump assembly.

Description

FIELD OF THE INVENTION

The present subject matter relates generally to water heater appliances, and more particularly to water heater appliances which utilized thermo-electric converters to improve water heater appliance efficiency.

BACKGROUND OF THE INVENTION

Certain water heater appliances include a tank therein. Heating elements, such as gas burners, electric resistance elements, or induction elements, heat water within the tank during operation of such water heater appliances. In particular embodiments, heat pump assemblies are utilized in water heater appliances, with the condenser of the heat pump acting as the heating element. The heating elements generally heat water within the tank to a predetermined temperature. The predetermined temperature is generally selected such that heated water within the tank is suitable for showering, washing hands, etc.
One goal in water heater appliance design is increasing the energy factor for the water heater appliance. Energy factor is generally utilized to compare the energy conversion efficiency of an appliance, such as a water heater appliance. Many typical water heater appliances have energy factors of less than 0.90. In conventional gas water heaters, the energy factors are commonly less than 0.60. Recently developed gas sorption cycle based water heater appliances, which utilize for example ammonia-water solutions or lithium bromide-water solutions as a working absorption refrigerant media, generate increased energy factors. However, these systems are expensive and complicated, and require an electrical current to maintain operation. In many cases, consumers are reluctant to convert to such systems due to the potential loss of ability to generate hot water during and due to power losses.
Accordingly, improved water heater appliances are desired. In particular, water heater appliances which provide improved energy factors, and which are not dependent upon mainline electricity for operation, would be advantageous.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one embodiment, a water heater appliance is disclosed. The water heater appliance includes a tank defining a chamber, the tank further defining an inlet aperture and an outlet aperture. The water heater appliance further includes a hot water conduit extending through the outlet aperture and in fluid communication with the chamber of the tank, the hot water conduit configured for directing a flow of water out of the chamber of the tank, and a cold water conduit extending through the inlet aperture and in fluid communication with the chamber of the tank, the cold water conduit configured for directing a flow of water into the chamber of the tank. The water heater appliance further includes a heat pump assembly configured to heat water within the chamber of the tank, and a thermo-electric assembly configured to generate an electrical current. The thermo-electric assembly includes a thermo-electric converter, a working fluid flowable through the thermo-electric converter, and a heat source configured to heat the working fluid within the thermo-electric converter. At least a portion of the electrical current generated by the thermo-electric assembly is flowed to the heat pump assembly to at least partially power the heat pump assembly.
In accordance with another embodiment, a water heater appliance is disclosed. The water heater appliance includes a tank defining a chamber, the tank further defining an inlet aperture and an outlet aperture. The water heater appliance further includes a hot water conduit extending through the outlet aperture and in fluid communication with the chamber of the tank, the hot water conduit configured for directing a flow of water out of the chamber of the tank, and a cold water conduit extending through the inlet aperture and in fluid communication with the chamber of the tank, the cold water conduit configured for directing a flow of water into the chamber of the tank. The water heater appliance further includes a heat pump assembly configured to heat water within the chamber of the tank, and a thermo-electric assembly configured to generate an electrical current. The thermo-electric assembly includes a thermo-electric converter, a working fluid flowable through the thermo-electric converter, and a heat source configured to heat the working fluid within the thermo-electric converter. The water heater appliance further includes a heat recovery vessel disposed at least partially within the chamber, the heat recovery vessel defining a passage extending between an inlet and an outlet, the inlet configured to receive exhaust fluid from the heat source therethrough. The water heater appliance further includes a condensing conduit connected at an inlet to the outlet of the heat recovery vessel, and an exhaust assembly exterior to the tank, the exhaust assembly connected to an outlet of the condensing conduit. At least a portion of the electrical current generated by the thermo-electric assembly is flowed to the heat pump assembly to at least partially power the heat pump assembly.
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

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.

FIG. 1 provides a perspective view of a water heater appliance in accordance with one embodiment of the present disclosure.

FIG. 2 provides a side cross-sectional view of a water heater appliance in accordance with one embodiment of the present disclosure.

FIG. 3 provides a side cross-sectional view of a water heater appliance in accordance with another embodiment of the present disclosure.

DETAILED DESCRIPTION

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.
FIG. 1 provides a perspective view of a water heater appliance 100 according to an exemplary embodiment of the present subject matter. Water heater appliance 100 includes a casing 102. A tank 101 (FIGS. 2 and 3) is positioned within casing 102 for heating water therein. As will be understood by those skilled in the art and as used herein, the term “water” includes purified water and solutions or mixtures containing water and, e.g., elements (such as calcium, chlorine, and fluorine), salts, bacteria, nitrates, organics, and other chemical compounds or substances.
Water heater appliance 100 also includes a cold water conduit 104 and a hot water conduit 106 that are both in fluid communication with a chamber 111 (FIGS. 2 and 3) defined by tank 101. As an example, cold water from a water source, e.g., a municipal water supply or a well, can enter water heater appliance 100 through cold water conduit 104 (shown schematically with arrow labeled F_cool). From cold water conduit 104, such cold water can enter chamber 111 of tank 101 wherein it is heated with heating elements, discussed herein, to generate heated water. Such heated water can exit water heater appliance 100 at hot water conduit 106 (shown schematically with arrow labeled F_hot) and, e.g., be supplied to a bath, shower, sink, or any other suitable feature.
Water heater appliance 100 extends longitudinally between a top portion 108 and a bottom portion 109 along a vertical direction V. Thus, water heater appliance 100 is generally vertically oriented. Water heater appliance 100 can be leveled, e.g., such that casing 102 is plumb in the vertical direction V, in order to facilitate proper operation of water heater appliance 100. A drain pan 110 is positioned at bottom portion 109 of water heater appliance 100 such that water heater appliance 100 sits on drain pan 110. Drain pan 110 sits beneath water heater appliance 100 along the vertical direction V, e.g., to collect water that leaks from water heater appliance 100 or water that condenses on an evaporator (not shown) of water heater appliance 100. It should be understood that water heater appliance 100 is provided by way of example only and that the present subject matter may be used with any suitable water heater appliance.
Water heater appliance 100 may further include a controller 134 (see FIGS. 2 and 3) that is configured for regulating operation of water heater appliance 100. Controller 134 may be in operative communication with various components of the water heater appliances, including, for example, heating elements and heating assemblies as discussed herein, a temperature sensor as discussed herein, and a control panel 107. Control panel 107 may include various displays and input controls for user interface with the appliance 100. Controller 134 can, for example, selectively activate heating elements in order to heat water within chamber 102 of tank 101.
Controller 134 includes 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 water heater appliance 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 134 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.
Referring now to FIGS. 2 and 3, tank 101 may define an inlet aperture 150 and an outlet aperture 152. The inlet and outlet apertures 150, 152 may be provided to facilitate the flow of water into and from the chamber 111. For example, cold water conduit 104 may extend through inlet aperture 150, and hot water conduit 106 may extend through outlet aperture 152. Apertures 150, 152 may in exemplary embodiments be define on an upper portion of the tank 101 along the vertical direction V, such that the conduits 104, 106 extend generally vertically into the chamber 111.
In exemplary embodiments, appliance 100 may include a temperature sensor 160. Temperature sensor 160 may generally sense the temperature in the appliance 100, such as of water in the chamber 111, and may for example be in operative communication with the controller 134.
Referring still to FIGS. 2 and 3, the present disclosure is further directed to water heater appliances 100 which provide improved energy factors. Water heater appliances in accordance with the present disclosure advantageously utilize heat pump assemblies and thermo-electric assemblies to heat water in tanks 101 thereof. The combined use of heat pump assemblies and thermo-electric assemblies as discussed herein advantageously improves the energy factor of the associated water heater appliance. For example, in some cases, an energy factor of greater than 1.5, such as greater than 1.7, is attainable in water heater appliances in accordance with the present disclosure. Further, advantageously, electrical current generated by the thermo-electric assembly of a water heater appliance in accordance with the present disclosure can be utilized to at least partially power the heat pump assembly and components thereof, as well as the controller 134 and various exhaust assembly components as discussed herein. This allows exemplary water heater appliances in accordance with the present disclosure to advantageously remain operational even during, for example, mainline power outages.
As illustrated, a water heater appliance 100 may include a heat pump assembly 200. Heat pump assembly 200 and the various components thereof may, for example, be in communication with the controller 134. Controller 134 may thus be operable to activate and deactivate the heat pump assembly 200 to heat water in the chamber 111. The heat pump assembly 200 may include, for example, a compressor 202, a condenser 204, an expansion device 206 and an evaporator 208. Tubing generally connects and extends between these various components of the heat pump assembly 200, and a refrigerant is flowed through the various components of through the tubing between the various components when the heat pump assembly 200 is active. Any suitable refrigerant may be utilized in a heat pump assembly 200 in accordance with the present disclosure. One exemplary refrigerant for use in a heat pump assembly 200 in accordance with the present disclosure is 1,1,1,2-tetrafluoroethane, also known as R-134A.
As is generally understood, the refrigerant is compressed within the compressor 202 and then flowed to the condenser 204. Condenser 204 in exemplary embodiments comprises a condenser conduit 210 which defines a passage therethrough, through which refrigerant from the compressor 202 is flowed. At least a portion of the condenser conduit 210 is in contact with the tank 101, such as with an exterior surface of the tank 101. For example, as illustrated, at least a portion of the condenser conduit 210 may be wrapped around the tank 101, such as in a generally helical manner. Heat exchange between the tank 101 (and water therein) and the conduit 210 (and refrigerant therein) may heat the water and cool the refrigerant via emission of heat from the refrigerant.
Condensed refrigerant from the condenser 204 may be flowed to and through the expansion device 206, where the pressure of the refrigerant is lowered. In exemplary embodiments as illustrated, expansion device 206 is a capillary tube. Alternatively, other suitable expansion devices 206 may be utilized. Refrigerant may be flowed from expansion device 206 to and through evaporator 208, wherein the refrigerant absorbs heat. An evaporator fan 212 may be utilized to direct air towards and past the evaporator 208 to facilitate heat exchange to heat the refrigerant. The refrigerant is then flowed back to the compressor 202 and the cycle is repeated as required or desired.
As further illustrated, water heater appliance 100 may further include a thermo-electric assembly 220 which is generally configured to generate an electrical current. In general, a thermo-electric assembly 220 converts heat to electrical energy. Thermo-electric assembly 220 and the various components thereof may, for example, be in communication with the controller 134. Controller 134 may thus be operable to activate and deactivate the thermo-electric assembly 220 to generate electricity. Assembly 220 may include, for example, a thermo-electric converter 222. Converter 222 generally includes anodes, cathodes, and other components suitable for converting heat from a working fluid to electrical energy. In exemplary embodiments, a thermo-electric converter 222 in accordance with the present disclosure is an alkali-metal thermo-electric converter 222. Examples of suitable thermo-electric converters 222 are provided in U.S. Pat. No. 8,865,999 to Rossi et al., entitled “Thermoelectric Converter with Projecting Cell Stack”, issued on Oct. 21, 2014, and which is incorporated by reference in its entirety herein.
Assembly 220 may additionally include a working fluid 224, which in exemplary embodiments is an alkali-metal working fluid 224. For example, in exemplary embodiments, working fluid 224 includes sodium. Working fluid 224 is flowable through the thermo-electric converter 222, wherein electrical current is generated by such flow therethrough.
Additionally, assembly 220 may include a heat source 226 which is configured to heat the working fluid 224 within the thermo-electric converter 222. Such heating of the working fluid 224 facilitates the conversion of the heat to electrical current within the converter 222. In exemplary embodiments, the heat source 226 is a gas burner, such as a natural gas burner as illustrated. Alternatively, other gas sources such as propane may be utilized, or other suitable heat sources may be utilized.
As discussed, the thermo-electric assembly 220 generates an electrical current. This electrical current may advantageously be utilized to at least partially power various other components of the appliance 100. Accordingly, electrical current may be flowed to these components to power them. For example, as illustrated, electrical wires 230 may be connected between the converter 222 and the various components which are powered by the generated electrical current. The current may flow through the wires to at least partially power the various components. Additionally, one or more transformers 232 may be provided between the converter 222 and the various components as required to convert the direct current (“DC”) electricity generated by the converter 222 to alternating current (“AC”) electricity utilized to power the various components.
In exemplary embodiments as illustrated, at least a portion of the electrical current generated by the thermo-electric assembly 220 may be flowed to the heat pump assembly 200 to at least partially power the heat pump assembly 200. For example, electrical current may be flowed to the compressor 202 and to the evaporator fan 212 to at least partially power these components of the heat pump assembly 200. Additionally or alternatively, at least a portion of the electrical current generated by the thermo-electric assembly 220 may be flowed to the controller 134 to at least partially power the controller 134. Additionally or alternatively, at least a portion of the electrical current generated by the thermo-electric assembly 220 may be flowed to components of an exhaust assembly as discussed herein to at least partially power the components of the exhaust assembly.
In some embodiments, between approximately 10% and approximately 40% of the thermal energy from the working fluid 224 can be converted to electricity. At least a portion of the remaining thermal energy, such as between approximately 60% and approximately 90% of the thermal energy, from the working fluid 224 can thus advantageously be utilized to heat water within chamber 111. For example, in exemplary embodiments, thermo-electric assembly 220 may further include a conduit 240 through which working fluid 224 may flow. Conduit 240 may define a passage 242 that extends between an inlet 244 and an outlet 246. The inlet 244 may be connected to and in fluid communication with the thermo-electric converter 222 for flowing the working fluid 224 from the thermo-electric converter 222 into the passage 242. The outlet 246 may be connected to an in fluid communication with the thermo-electric converter 222 for flowing the working fluid 224 from the passage 242 into the thermo-electric converter 222. Accordingly, working fluid 224 may have a closed-loop flow path between the converter 222 and conduit 240.
The working fluid 224 exiting converter 222 into conduit 240 may be relatively hot working fluid 224 which has been heated by heat source 226. The working fluid 224 entering converter 222 from conduit 240 may be relatively cool working fluid 224 which has undergone heat exchange and thus emitted heat. For example, in some embodiments, as illustrated in FIG. 2, at least a portion of the conduit 240 may be in contact with the tank 101, such as with an exterior surface of the tank 101. For example, as illustrated, at least a portion of the conduit 240 may be wrapped around the tank 101, such as in a helical manner. Heated working fluid 224 may be flowed into and through the conduit 240. Heat exchange between the tank 101 (and water therein) and the conduit 240 (and working fluid 224 therein) may heat the water and cool the working fluid 224 via emission of heat from the working fluid 224. The cooled working fluid 224 may then be flowed from conduit 240 into converter 222, wherein the working fluid 224 may again be heated by heat source 226.
In other embodiments, as illustrated in FIG. 3, heat exchange may occur with an auxiliary assembly rather than directly between the tank 101 (and water therein) and the conduit 240 (and working fluid 224 therein). For example, assembly 220 may further include an auxiliary fluid tank 250 and an auxiliary conduit 252. An auxiliary fluid 254 may be flowed into and through the tank 250 and conduit 252. In exemplary embodiments, the auxiliary fluid 254 may be water or another suitable liquid. Conduit 252 may define a passage 262 that extends between an inlet 264 and an outlet 266. The inlet 264 may be connected to and in fluid communication with the tank 250 for flowing the auxiliary fluid 254 from the tank 250 into the passage 262. The outlet 266 may be connected to and in fluid communication with the tank 250 for flowing the auxiliary fluid 254 from the passage 262 into the tank 250. Accordingly, auxiliary fluid 254 may have a closed-loop flow path between the tank 250 and conduit 252. Notably, in some embodiments, assembly 220 may additionally include a pump 256 disposed at least partially in auxiliary fluid tank 250 for flowing auxiliary fluid 254 from tank 250 through inlet 264 into passage 262.
A portion of the conduit 240 may be disposed within the auxiliary fluid tank 250 as illustrated or in contact with the auxiliary fluid tank 250 (such as with an exterior surface thereof). Heated working fluid 224 may be flowed into and through the conduit 240. Heat exchange between the tank 250 (and auxiliary fluid 254 therein) and the conduit 240 (and working fluid 224 therein) may heat the auxiliary fluid 254 and cool the working fluid 224 via emission of heat from the working fluid 224. The cooled working fluid 224 may then be flowed from conduit 240 into converter 222, wherein the working fluid 224 may again be heated by heat source 226.
The auxiliary fluid 254 exiting tank 250 into conduit 252 may thus be relatively hot auxiliary fluid 254 which has been heated by such heat exchange. The auxiliary fluid 254 entering tank 250 from conduit 252 may be relatively cool auxiliary fluid 254 which has undergone heat exchange and thus emitted heat. For example, in some embodiments, as illustrated in FIG. 3, at least a portion of the conduit 252 may be in contact with the tank 101, such as with an exterior surface of the tank 101. For example, as illustrated, at least a portion of the conduit 252 may be wrapped around the tank 101, such as in a helical manner. Heated auxiliary fluid 254 may be flowed into and through the conduit 252. Heat exchange between the tank 101 (and water therein) and the conduit 252 (and auxiliary fluid 254 therein) may heat the water and cool the auxiliary fluid 254 via emission of heat from the auxiliary fluid 254. The cooled auxiliary fluid 254 may then be flowed from conduit 252 into tank 250, wherein the auxiliary fluid 254 may again be heated by heat exchange between the tank 250 (and auxiliary fluid 254 therein) and the conduit 240 (and working fluid 224 therein).
Referring again to FIGS. 2 and 3, appliance 100 may further include a heat recovery vessel 270. Heat recovery vessel 270 may be disposed at least partially within the chamber 111, and may thus for example, extend through the tank 101 into the chamber 111. Vessel 270 may define a passage 272 extending between an inlet 274 and an outlet 276. The outlet 276 may be disposed within the chamber 211. The inlet 274 may be configured to receive exhaust fluid (such as exhaust gas) from the heat source 226 therethrough, and thus for example, may be disposed exterior to tank 101. For example, inlet 274 may be positioned to receive exhaust fluid from heat source 226 as the exhaust fluid flows past thermo-electric converter 222, as illustrated. The exhaust fluid may include heat not emitted to converter 222 and working fluid 224 therein. This exhaust fluid may flow through inlet 274 into and through passage 272. During such flow through passage 272, heat exchange may occur through the vessel 270 between the water in the chamber 211 and the exhaust fluid in the vessel 270, thus heating the water and cooling the exhaust fluid. In some embodiments, vessel 270 may further include fins 278 projecting to the chamber 211 to further facilitate such heat exchange.
Exhaust fluid flowing through passage 272 may exit passage 272 through outlet 276, and may further flow to exterior to tank 101 to be exhausted from appliance 100. For example, in some embodiments, a condensing conduit 280 may be connected to the vessel 270. Condensing conduit 280 may define a passage 282 extending between and inlet 284 and an outlet 286. Inlet 284 may be connected to outlet 276, such that exhaust fluid flows from passage 272 into passage 282. The exhaust fluid may further flow through condensing conduit 280, wherein further heat exchange may occur between the water in the chamber 211 and the exhaust fluid in the conduit 280, thus heating the water and cooling the exhaust fluid. The outlet 286 of conduit 280 may be disposed exterior to the tank 101 (and may further be exterior to the casing 102 as illustrated). Cooled exhaust fluid may exit conduit 280 through outlet 286.
In some embodiments, appliance 100 may further include an exhaust assembly 290 which may be connected to the outlet 286 of the condensing conduit 280. Exhaust assembly 290 may, for example, be disposed exterior to the tank 101 (and may further be exterior to the casing 102 as illustrated). Exhaust assembly 290 may receive exhaust fluid from the vessel 270 generally, such as from the condensing conduit 280, and may exhaust the exhaust fluid therefrom. For example, exhaust assembly 290 may include a housing 296, vent 298, exhaust fan 292 and drain 294 (which may for example be a preexisting drain of a home or office to which the appliance is coupled). Exhaust fluid may flow from outlet 286 into housing 296. Gaseous components of the exhaust fluid may flow through vent 298 to be exhausted, and this flow may be encouraged by fan 292. Liquid components of the exhaust fluid may flow through drain 294 to be exhausted. Notably, in exemplary embodiments, at least a portion of the electrical current generated by the thermo-electric assembly 220 may be flowed to fan 292 to at least partially power the fan 292.
As discussed, water heater appliances 100 in accordance with the present disclosure advantageously operate with improved energy factors. In particular, the combined use of heat pump assemblies and thermo-electric assemblies as discussed herein, and in particular the use of the electrical current generated by the thermo-electric assemblies to power various other components of the water heater appliances 100, advantageously improves the energy factor of the associated water heater appliance. Additionally, the use of heat recovery vessels 270 and other components as disclosed herein advantageously provides further increased and efficient heat exchange, thus further contributing to the improved energy factors of water heater appliances in accordance with the present disclosure.
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.

Claims

What is claimed is:

1. A water heater appliance, comprising:

a tank defining a chamber, the tank further defining an inlet aperture and an outlet aperture;

a hot water conduit extending through the outlet aperture and in fluid communication with the chamber of the tank, the hot water conduit configured for directing a flow of water out of the chamber of the tank;

a cold water conduit extending through the inlet aperture and in fluid communication with the chamber of the tank, the cold water conduit configured for directing a flow of water into the chamber of the tank;

a heat pump assembly configured to heat water within the chamber of the tank; and

a thermo-electric assembly configured to generate an electrical current, the thermo-electric assembly comprising an thermo-electric converter, a working fluid flowable through the thermo-electric converter, and a heat source configured to heat the working fluid within the thermo-electric converter,

wherein at least a portion of the electrical current generated by the thermo-electric assembly is flowed to the heat pump assembly to at least partially power the heat pump assembly.

2. The water heater appliance of claim 1, wherein the working fluid is an alkali-metal working fluid.

3. The water heater appliance of claim 1, wherein the thermo-electric assembly further comprises a conduit, the conduit defining a passage extending between an inlet and an outlet for flowing the working fluid therethrough, the inlet in fluid communication with the thermo-electric converter for flowing the working fluid from the thermo-electric converter into the passage, the outlet in fluid communication with the thermo-electric converter for flowing the working fluid from the passage into the thermo-electric converter.

4. The water heater appliance of claim 3, wherein a portion of the conduit is in contact with the tank.

5. The water heater appliance of claim 4, wherein the portion of the conduit is generally helically wrapped around the tank.

6. The water heater appliance of claim 3, wherein the thermo-electric assembly further comprises an auxiliary fluid tank and an auxiliary conduit, the conduit defining a passage extending between an inlet and an outlet for flowing an auxiliary fluid therethrough, the inlet in fluid communication with the auxiliary fluid tank for flowing the auxiliary fluid from the auxiliary fluid tank into the passage, the outlet in fluid communication with the auxiliary fluid tank for flowing the auxiliary fluid from the passage into the auxiliary fluid tank.

7. The water heater appliance of claim 6, wherein a portion of the auxiliary conduit is in contact with the tank.

8. The water heater appliance of claim 1, wherein the heat source is a gas burner.

9. The water heater appliance of claim 8, wherein the gas burner is a natural gas burner.

10. The water heater appliance of claim 1, further comprising a heat recovery vessel disposed at least partially within the chamber, the heat recovery vessel defining a passage extending between an inlet and an outlet, the inlet configured to receive exhaust fluid from the heat source therethrough.

11. The water heater appliance of claim 10, further comprising a condensing conduit connected at an inlet to the outlet of the heat recovery vessel.

12. The water heater appliance of claim 11, further comprising an exhaust assembly exterior to the tank, the exhaust assembly connected to an outlet of the condensing conduit.

13. The water heater appliance of claim 12, wherein the exhaust assembly comprises an exhaust fan and a vent.

14. The water heater appliance of claim 13, wherein at least a portion of the electrical current generated by the thermo-electric assembly is flowed to the exhaust fan to at least partially power the exhaust fan.

15. The water heater appliance of claim 1, further comprising a controller, and wherein at least a portion of the electrical current generated by the thermo-electric assembly is flowed to the controller to at least partially power the controller.

16. A water heater appliance, comprising:

a heat pump assembly configured to heat water within the chamber of the tank;

a thermo-electric assembly configured to generate an electrical current, the thermo-electric assembly comprising an thermo-electric converter, a working fluid flowable through the thermo-electric converter, and a heat source configured to heat the working fluid within the thermo-electric converter;

a heat recovery vessel disposed at least partially within the chamber, the heat recovery vessel defining a passage extending between an inlet and an outlet, the inlet configured to receive exhaust fluid from the heat source therethrough;

a condensing conduit connected at an inlet to the outlet of the heat recovery vessel; and

an exhaust assembly exterior to the tank, the exhaust assembly connected to an outlet of the condensing conduit,

17. The water heater appliance of claim 16, wherein the thermo-electric assembly further comprises a conduit, the conduit defining a passage extending between an inlet and an outlet for flowing the working fluid therethrough, the inlet in fluid communication with the thermo-electric converter for flowing the working fluid from the thermo-electric converter into the passage, the outlet in fluid communication with the thermo-electric converter for flowing the working fluid from the passage into the thermo-electric converter.

18. The water heater appliance of claim 16, wherein the exhaust assembly comprises an exhaust fan and a vent.

19. The water heater appliance of claim 18, wherein at least a portion of the electrical current generated by the thermo-electric assembly is flowed to the exhaust fan to at least partially power the exhaust fan.

20. The water heater appliance of claim 16, further comprising a controller, and wherein at least a portion of the electrical current generated by the thermo-electric assembly is flowed to the controller to at least partially power the controller.