Boost Heat Pump Water Heater

Abstract

Disclosed is a hybrid heat pump water heater that maintains the overall efficiency of a heat pump water heater over a conventional electric resistance water heater, while simultaneously allowing for the water heater to temporarily boost, using electrical heating elements, the rate at which the water is heated to a setpoint temperature during times of immediate demand. This hybrid heat pump water heater not only addresses these immediate demand scenarios, but also ensures that the water heater remains in compliance with regulations regarding continuous use water heaters. Specifically, a controller enables an electrical heating element that pulls a maximum power draw from a power source until a threshold amount of time has elapsed and then switches to a lower power electrical heating element that draws less than the maximum current from the power source.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. application Ser. No. 63/765,363, filed Feb. 28, 2025, the entirety of which is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure is generally in the field of water heaters.

BACKGROUND

A heat pump water heater (HPWH) is a more efficient alternative to a conventional electric resistance water heater. Generally, a HPWH functions by transferring heat from the surrounding air to heat the water, rather than generating heat directly in the water using a heating element, such as a resistive heating element.

In one or more embodiments, a heat pump water heater may have an evaporator coil and a fan that draws in air from the surrounding environment. The evaporator coil may include a refrigerant fluid, which absorbs the heat from the air. The refrigerant is at a low temperature when the refrigerant enters the evaporator coil, and as it absorbs heat from the air, the refrigerant evaporates. The refrigerant gas is then pumped into a compressor, which increases the pressure of the gas. This compression process significantly raises the temperature of the gas, making the gas much hotter than the surrounding air. The hot, pressurized refrigerant gas then flows through a condenser coil located near the water tank. As the gas travels through the condenser coil, the gas releases its heat to the water stored in the tank. The heat is transferred from the refrigerant to the water, warming it up. Once the refrigerant has released its heat, it cools down and condenses back into a liquid. This liquid refrigerant then passes through an expansion valve, which reduces its pressure and lowers its temperature.

However, heat pump water heaters exhibit slower recovery times compared to the more traditional electric resistance heating mechanisms. This may be undesirable in some scenarios in which a user desires immediate usage of hot water but the water is not currently at the setpoint temperature desired by the user. That is, the time required to bring the temperature of the water up to the temperature setpoint to delivery to the user may be greater in a heat pump water heater than a conventional electric resistance water heater.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a flow diagram for the operation of an on-demand heat pump water heater, in accordance with one or more embodiments of the disclosure.

FIG. 2 illustrates a circuit schematic for control of an on-demand heat pump water heater, in accordance with one or more embodiments of the disclosure.

FIG. 3 illustrates a schematic view of an example on-demand heat pump water heater, in accordance with one or more embodiments of the disclosure.

FIG. 4 illustrates an example on-demand heat pump water heater, in accordance with one or more embodiments of the disclosure.

FIG. 5 illustrates an exemplary controller, in accordance with one or more embodiments of the disclosure.

DETAILED DESCRIPTION

The present disclosure is directed to a boosted heat pump water heater, though the present disclosure is applicable to heating other types of fluids. Specifically, the water heater may be a hybrid heat pump water heater (also generally referred to herein as an “on-demand heater pump water heater” or the like) that maintains the overall efficiency of a heat pump water heater over a conventional electric resistance water heater, while simultaneously allowing for the water heater to temporarily boost the rate at which the water is heated to a setpoint temperature during times of high demand. That is, during normal operation, the water heater may operate as a traditional heat pump water heater without using any electrical heating elements to heat the water or together with a lower electrical heating element (the combination of the heat pump water heater and the lower electrical heating element may be referred to herein as the “primary heating system,” however, these elements may also be powered individually). During times of high demand, an upper electrical heating element (also referred to herein as the “booster heating system”) may be powered to heat the water and reduce the amount of time to raise the temperature of the water to the setpoint temperature desired by the user. The upper electrical heating element is a higher power electrical heating element than the lower electrical heating element, if present, and draws the same as or more current than the heat pump water heater or the combination of the heat pump water heater and the lower heating element. A relay may be positioned to switch between powering just the upper heating element or to power the heat pump water heater or a combination of the heat pump water heater and the lower heating element. Therefore, a single circuit may be used to supply power from the electric mains to the hybrid heat pump water heater while still allowing for both the normal and high demand modes of operation.

The term high demand, for example, may refer to periods characterized by the continuous draw of water (or another fluid) for a given amount of time. In a residential setting, continuous back-to-back shower usage is one example of a high demand scenario. This high demand may be detected using various methods. As one example, the high demand may be detected using a flow meter (such as flow 306, as one example). If a flow meter detects that water (or another fluid) is flowing at or above a threshold rate, such as above a given number of gallons per minute (GPM) (e.g., 1.5 GPM or any other value) for a given period of time (e.g., seven minutes) with any pauses between flow being shorter than a certain amount of time, then a high demand scenario may exist. As another example, the high demand may also be detected based on temperature changes (for example, using temperature sensors 308a, 308b, or any other temperature sensors). The wall of the of the water heater tank may include temperature sensors (however, the temperature sensors may also be positioned at any other location). During high demand, there is more hot water (or any other fluid) output, which means there is more cold water input. This can be detected in two ways. First, the time difference between two different temperature sensors sensing cold incoming water. Second, if a temperature sensor at height ‘X’ detects cold water, then high demand mode may be run until a temperature sensor at height ‘Y,’ which is lower than ‘X,’ detects hot water again. (For example, if a sensor at the top of the tank detects cold water, the system may initiate high demand mode until a sensor near the bottom detects hot water). This definition of high demand is merely exemplary and other definitions may also be applicable. Also, the above mentioned methods for determining high demand are also merely exemplary and other methods may also be possible.

The water heater may include multiple electrical heating elements disposed at various locations within the tank of the water heater. These electrical heating elements may be, for example, resistive heating elements that are heated based on current supplied into the resistive heating elements, however, any other type of heating element may be used to supplement the heating operation of the heat pump (or alternatively be used instead of the heat pump). Therefore, any reference herein to an electrical heating element (or the like) is merely exemplary and not intended to limit the scope of the type of heating element that may be used to supplement the heating provided by the heat pump during immediate demand scenarios.

In one or more embodiments (and as illustrated through at least FIG. 4), the water heater may include a first electrical heating element disposed in a top portion of the tank and a second electrical heating element disposed in a bottom portion of the tank. In some instances, the first electrical heating element may specifically be positioned proximate to the fluid outlet of the tank (for example, the outlet of the tank via which heated water is routed out of the water heater and towards the load that is demanding the heated water). However, the first and second electrical heating elements may also be disposed at any other locations in the tank. Additionally, there may be any other number of electrical heating elements as well. For example, there may be a single electrical heating element, three electrical heating elements, four electrical heating elements, etc.

This hybrid heat pump water heater not only addresses immediate demand scenarios, but also ensures that the higher power rating electric heating element is not continuously used for more than a threshold period of time, such that the water heater remains in compliance with any regulations relating to the usage of continuous water heaters (for example, Utilization of the NEC Continuous Duty Clause per NEC 522.30 and 522.31 or any other relevant regulations).

Accordingly, electrical heating elements of different power ratings may be used with the water heater. For example, the first electrical heating element may be a 7 kW heating element and the second electrical heating element may be a 4.5 kW heating element. Initially, during the high demand scenario, the 7 kW electrical heating element may be used to draw the maximum amount of current or close to a maximum amount of current (e.g., within 1 amp, within 3 amps, within 5 amps, etc.) from the power source to which the electrical heating elements are electrically connected. If the high demand scenario necessitates the use of the upper electrical heating element for more than a threshold period of time (for example, three hours per the regulations or any other designated amount of time), then the water heater may deactivate the 7 kW heating element and may instead use the heat pump water heater and the 4.5 kW heating element that draws less than the maximum amount of current from the power source. These values are merely used for exemplary purposes and heating elements of other power ratings may also be used.

For example, in a 30-amp circuit, the heat pump and/or the 4.5 kW lower heating element may be rated for 24 amp continuous operation during normal operation. However, on the same circuit, the upper heating element may be rated for non-continuous operation at the full 30 amps. Therefore, when powering the 7 kW upper heating element on a 240 V line, the upper heating element may draw about 29 amps (+/−0.5-3%).

To provide for the selective use of the higher and lower power electrical heating elements, a circuit may be provided in (and/or on) the water heater (an example of this circuit is illustrated in FIG. 2). The circuit may include at least the power source, the electrical heating elements, a controller, and a relay provided between the power source and the electrical heating elements. The circuit may operate to provide power to either the first heating element in a first configuration or to the heat pump water heater and the second heating element in a second configuration (or just the heat pump water heater or any other number of electrical heating elements depending on the specific configuration). When there is a high demand for hot water, the relay may be switched to connect the higher power rating first heating element to the power source to heat the water in the tank at a faster rate to accommodate the demand for hot water. The circuit is also configured such that the relay is automatically controlled to switch between supplying power from the first configuration to the second configuration when the first heating element has been active for a threshold period of time. For example, the controller may send a signal to the relay to automatically perform the transition, however, the relay may be controlled in other ways.

The heat pump water heater described herein provides a number of benefits over an existing heat pump water heater. For example, the improved heat pump water heater provides a significant improvement in the First Hour Rating (FHR) of the water heater, which is the amount of hot water that the water heater can provide in the first hour of operation. The improved heat pump water heater also allows for a smaller compressor to be used, leading to a higher Uniform Energy Factor (UEF) and improved recovery time over existing heat pump water heaters.

While reference is made specifically to heat pump water heaters, the same principles may be applicable to any other type of water heater. For example, the water heater may be a tankless water heater (as described below, a “tankless” water heater may still include a smaller storage tank for temporarily holding water) or a water heater that includes a designated storage tank for holding the water.

Turning to the figures, FIG. 1 illustrates a flow diagram 100 for the operation of an on-demand heat pump water heater (for example, water heater 300, water heater 400, etc.). In one or more embodiments, any of the steps of the flow diagram 100 may be performed by a controller of the water heater (such as controller 206, controller 330, controller 500, etc.). Furthermore, one of skill in the art will understand that the logic depicted in FIG. 1 can be altered as necessary to encompass the many different configurations of the on-demand heat pump water heater 100 as previously discussed or other configurations not discussed.

In an example, as shown in FIG. 1, the controller can perform a sequence of logic checks to operate the heat pump and the electrical heating elements and regulate the temperature of the fluid based on a predetermined temperature setting (also generally referred to as a temperature setpoint herein). In this example, the controller can receive temperature data from a temperature sensor (for example, temperature sensors 308a, 308b) and determine (at step 152) if the temperature of the fluid in the low fluid capacity heating chamber is below a predetermined temperature setting.

If the temperature of the fluid in the low fluid capacity heating chamber is below the predetermined temperature setting, then, depending on whether there is high demand (step 154), the controller can send a control signal to the heat pump and/or lower heating element to engage (at step 156) and begin heating the fluid, or the controller can send a control signal to the upper heating element to engage (at step 158). A period of high demand may be determined using any suitable method described herein or otherwise. For example, as described above, the high demand may be determined based on fluid flow data (such as data from a flow sensor 306, for example) and/or temperature data (such as temperature sensors 308a, 308b, for example).

Specifically, if the controller determines there is high demand, then the controller may send the signal to turn on the upper heating element (step 158). If the controller determines there is not high demand, then the controller may send the signal to turn on the heat pump and/or the lower heating element (step 156). If the controller determines that the upper heating element has been engaged for a threshold period of time (step 160), then the controller may send a signal to turn off the upper heating element. If the temperature is still below the set point, then the controller may send a signal to the heat pump and/or lower heating element to engage. After a given amount of time has passed since turning off the upper heating element (and if there is still high demand), the controller may send a signal to turn on the upper heating element and turn off the lower heating element and/or the heat pump to heat the water (or other fluid) at a quicker rate. If the temperature of the fluid in the low fluid capacity heating chamber is above the predetermined temperature setting, the controller can send a control signal to the heat pump to disengage and cease heating the fluid.

This is merely one example of a method of controlling the on-demand heat pump water heater, and one of skill in the art will understand that the controller can be configured to control alternate configurations of the on-demand heat pump water heater and the controller can accordingly have multiple configurations functionalities as described herein. Furthermore, although this immediate example does not discuss the use of a mixing valve, one of skill in the art will understand that a mixing valve can be integrated into this and other examples.

FIG. 2 illustrates a schematic for a circuit 200 for control of a heat pump water heater (such as water heater 300, water heater 400, or any other water heater described herein or otherwise). In one or more embodiments, the circuit 200 may include a power source 202, a relay 204, a controller 206 (which may be the same as controller 330, controller 500, etc.), a primary heating system 208, and a booster heating system 210. The primary heating system 208 may include a heat pump water heater (e.g., with a condenser 411 of the heat pump wrapped around the tank water heater for heating water stored therein) and/or a lower heating element (for example, second electrical heating element 408, electrical heating element 362a, etc.). The booster heating system 210 may include an upper heating element (for example, first electrical heating element 406, electrical heating element 360, etc.) that draws more current than the heat pump water heater and/or the lower heating element. Accordingly, any reference herein to a lower heating element and/or heat pump water heater may refer to the primary heating system and any reference to an upper heating element may refer to the booster heating system as shown in FIG. 2. The specific circuit 200 shown in FIG. 2 is merely one exemplary configuration for a water heater that includes a heat pump water heater and two heating elements (for example, a lower heating element and an upper heating element as shown in FIG. 1), this is not intended to be limiting and a water heater may also include any other number of heating elements. For example, in some implementations, the water heater may omit the lower heating element.

In one or more embodiments, the circuit 200 may operate to provide power to either the primary heating system 208 or the booster heating system 210. When there is a high demand for hot water, the relay 204 may be switched to connect the higher power rating booster heating system 210 to the main power source 202 to heat the water in the tank at a faster rate to accommodate the increased demand for hot water. For example, the booster heating system 210 may be configured for maximum current draw from the power source to minimize the amount of time it takes for the water heater to heat the water to satisfy the demand, thereby improving the FHR of the water heater. In one exemplary implementation, the main power source 202 is configured to provide a maximum current draw of 30 A and the booster heating system 210 is a 7 kW heating element (however, these values may differ depending on the specific system configuration).

The circuit 200 is also configured such that the relay 204 is automatically controlled to switch between supplying power from the main power source 202 from the booster heating system 210 to the primary heating system 208 (e.g., the heat pump and/or lower heating element, as described above) when the booster heating system 210 has been active for a threshold period of time. For example, the controller 206 may send a signal to the relay 204 to automatically perform the transition, however, the relay 204 may be controlled in any other suitable way as well. The threshold period of time may be the three hours specified by NEC Code 522-10, however, other thresholds may also be used. This circuit 200 allows a water heater to significantly improve its FHR and satisfy immediate hot water demand while also allowing the water heater to remain in compliance with NEC Code 522-10 and other related regulations relating to a continuous load.

During normal modes of operation when there is not a high demand for hot water, the relay 204 is switched such that the primary heating system 208 is connected to the main power source 202. That is, during normal modes of operation when there is not high demand, the heat pump and/or the lower heating element may be powered to heat the water (or other fluid).

In one or more embodiments, there may also be several sub-categories of “normal mode of operation”. For example, there may be an energy saving mode in which only the heat pump water heater is used to heat the water and the lower heating element is disengaged. There may also be any other sub-categories of this normal mode of operation using one or both of the heat pump water heater and the lower heating element (and at varying capacities).

While reference is made to the use of a relay to selectively provide an electrical connection between the power source 202 and either the primary heating system 208 (and the heat pump) or the booster heating system 210, one of ordinary skill in the art would understand that other types of components may also be used in place of a relay to provide a similar switching function. Further non-limiting examples of such components may include contactors, solid state relays, or any other type of electrical switching device that allows one circuit to operate at a time.

FIG. 3 is a schematic view of an example heat pump water heater 300 that includes a low fluid capacity heating chamber 301, a fluid inlet 302, a fluid outlet 304, a flow sensor 306 (or any other number of flow sensors), a temperature sensor (e.g., one or both of temperature sensors 308a, 308b, or any other number of temperature sensors), a heat pump 320, and a controller 330. The heat pump 320 comprises a condenser 322, an expansion valve 324, an evaporator 326, and a compressor 328. Optionally, the heat pump can include or be in communication with a ventilation system 329 to cool the heat pump 320. The controller 330 can control the heat pump 320 to maintain the temperature of the fluid at a predetermined temperature setting (e.g., a predetermined value, a predetermined range of values) by analyzing data received from the flow sensor 306 and/or the temperature sensor(s) 308a, 308b. One of skill in the art will understand that FIG. 3 is an example for illustrative purposes and that the various components of the heat pump water heater 300 can be arranged in various orders, locations, and configurations. Additionally, a heat pump water heater may also include any other components (including additional components or fewer components depending on the specific configuration of the particular heat pump water heater). Furthermore, as indicated above, the methods described herein may be applicable to any other type of water heater and the depiction of the tankless heat pump water heater shown in FIG. 3 is not intended to limit the scope of the method.

Although commonly referred to as “tankless” water heaters, on-demand water heaters often use some form of small storage tank in which to heat the water. The low fluid capacity heating chamber 301 can be used as a temporary storage location for the heat pump 320 to add heat to the water. The low fluid capacity heating chamber 301 can be sized for various applications. For example, the low fluid capacity heating chamber 301 can have a capacity of fifteen gallons or less for a typical usage application. As another example, the low fluid capacity heating chamber 301 can be sized between one and two gallons for use with a bathroom sink in a user's home, as based on the average user's demand for hot water. Depending on the application, the low fluid capacity heating chamber 301 can have a capacity of 0.25 gallons, 0.5 gallons, 1 gallon, 1.5 gallons, 2, gallons, 2.5 gallons, 3 gallons, 3.5 gallons, 4 gallons, 4.5 gallons, 5 gallons, or any other appropriate size to fit the particular application. For example, the low fluid capacity heating chamber 301 can have a capacity of ten gallons, fifteen gallons, or more. The low fluid capacity heating chamber 301 can be sized to meet Department of Energy (DOE) conservation standards for consumer water heaters. For example, the low fluid capacity heating chamber can be less than 2 gallons to meet DOE standards for electric instantaneous water heaters found in 30 C.F.R. 530.32(d) (or any other relevant standards). The low fluid capacity heating chamber 301 may generally be referred to as a heating chamber and have any size capacity, including up to 80 gallons or more.

The low fluid capacity heating chamber 301 can be made of any suitable material for storing and heating water, including copper, carbon steel, stainless steel, ceramics, polymers, composites, or any other appropriate material. Furthermore, the low fluid capacity heating chamber 301 can be treated or lined with a coating to prevent corrosion and leakage. An appropriate treating or coating will be capable of withstanding the demand temperature of the heated water and pressure of the system and can include, as non-limiting examples, glass enameling, galvanizing, thermosetting resin-bonded lining materials, thermoplastic coating materials, cement coating, or any other appropriate treating or coating for the application. Optionally, the low fluid capacity heating chamber 301 can be insulated to retain heat. For example, the low fluid capacity heating chamber 301 can also be insulated using fiberglass, aluminum foil, organic material, or any other appropriate insulation material.

As shown in FIG. 3, the disclosed technology can include a heat pump 320 to heat water. The heat pump 320 can be any suitable form of heat pump that can be used to heat water, including compression-or absorption-type heat pumps. The heat pump 320 can be adapted to use an air source, ground source, water source, or any other heat source. The heat pump 320 can also be a geothermal, air-to-water, water-to-water, liquid-to-water, or any other type of heat pump system that is appropriate for the particular application. As an example, the heat pump 320 can be an air source type heat pump, which utilizes a refrigerant in a vapor-compression cycle, but the type of heat source can be modified depending on the particular application. Furthermore, the heat pump 330 can be a single-stage, two-stage, or variable capacity heat pump, depending on the application.

The heat pump 320 can include a condenser 322, an expansion valve 324, an evaporator 326, and a compressor 328. The various components can be sized, shaped, and located as is appropriate for the particular application. For example, the compressor 328 can be powered by any appropriate energy source, including electrical power, a combustion engine, or any other energy source capable of operating the compressor 328. The compressor 328 can be any type of compressor. For example, the compressor 328 can be a positive displacement compressor, a reciprocating compressor, a rotary screw compressor, a rotary vane compressor, a rolling piston compressor, a scroll compressor, a diaphragm compressor, a dynamic compressor, an axial compressor, or any other form of compressor that can be integrated into a heat pump. The condenser 322 may be fluidly isolated from the heating chamber 301 (e.g., with one or more heat transfer medium for transferring heat from the condenser 322 to the heating chamber 301) or otherwise positioned in direct contact with the fluid in the heating chamber 301 (e.g., submerged condenser).

The condenser 322 can be installed in a position that improves energy transfer to the water in the low fluid capacity heating chamber 301. On the other hand, the evaporator 326 can be located where it can absorb heat from its surroundings. As discussed above, this can include any heat source, such as air, water, or geothermal sources. Both the condenser 322 and the evaporator 326 can be made of material(s) that can effectively exchange heat, including copper, aluminum, stainless steel, gold, silver, gallium, indium, thallium, graphite, composite materials, or any other material that is appropriate for a given application. A given application can have specific system requirements, such as, as non-limiting examples, the desired water temperature, heat transfer rate (e.g., Btu/hr required to heat the source water), environmental conditions (e.g., the climate in which the system is installed), and cost considerations. Furthermore, the expansion valve can be any type of expansion valve. For example, the expansion valve 324 can be a thermal expansion valve, a manual expansion valve, an automatic expansion valve, an electronic expansion valve, a low-pressure float valve, a high-pressure float valve, capillary tubes, or any other form of expansion valve appropriate for the application. The size, type, and installed location of the expansion valve 324 can vary depending on the application, which can be influenced by the above system requirements or other considerations.

The heat pump water heater 300 can include various sensing devices that collect data about the water in the system. FIG. 3 shows a flow sensor 306 and temperature sensors 308a, 308b. The flow sensor 306 is shown as being installed just downstream of the fluid inlet 302 but can be installed in alternative locations that are in fluid communication with the low fluid capacity heating chamber 301. For example, the flow sensor 306 can be installed just downstream of the fluid inlet, inside the low fluid capacity heating chamber 301, downstream of the low fluid capacity heating chamber 301, or even upstream of the fluid inlet 302 or downstream of the fluid outlet 304 so long as the flow sensor 306 is able to detect a positive flow (fluid flowing through the low fluid capacity heating chamber 301 in the direction from the fluid inlet 302 and toward the fluid outlet 304) of a fluid flowing into the low fluid capacity heating chamber 301.

Regardless of position, the flow sensor 306 can detect the flow rate of the fluid at the location of the flow sensor and can transmit flow data indicative of the flow rate to the controller 330. The flow sensor 306 can be any type of flow sensor and can be configured to simply detect fluid flow or can be used to detect the rate of flow of the fluid. If it is desirable to simply measure the presence of fluid flow, the flow sensor 306 can be a flow switch. If the flow sensor 306 is a flow switch, it can be a vane actuated flow switch, a disc actuated flow switch, a liquid flow switch, or any other appropriate type of flow switch for the application. If it is desirable to measure the rate of fluid flow, the flow sensor 306 can be a flow meter or another type of rate-measuring flow sensor. For example, the flow sensor 306 can be a differential pressure flow meter, a positive displacement flow meter, a velocity flow meter, a mass flow meter, an open channel flow meter, or any other type of flow meter configured to measure the flow rate of a fluid. The type of flow sensor 306 used will depend on the type of fluid being measured, its temperature and pressure, viscosity, conductivity, corrosiveness, and cleanliness required of the system.

Similar to the flow sensor 306, the temperature sensor(s) 308a, 308b can be installed in any appropriate location that allows the temperature sensor(s) 308a, 308b to detect temperature data of fluid at the installed location of the temperature sensor(s) 308a, 308b. Although two temperature sensors 308a and 308b are shown in FIG. 3, the heat pump water heater 300 can include only a single temperature sensor. For example, the heat pump water heater 300 can include only temperature sensor 308a to measure the temperature of the fluid within the low fluid capacity heating chamber 301, or the heat pump water heater 300 can include only temperature sensor 308b to measure the temperature of the fluid exiting the low fluid capacity heating chamber 301. Alternatively, the heat pump water heater 300 can include two temperature sensors as depicted in FIG. 3, or can include three, four, five, or more temperature sensors.

Referring to the dual temperature sensor example shown in FIG. 3, one temperature sensor 308a can be installed in the low fluid capacity heating chamber 301 to detect the temperature of the fluid inside the low fluid capacity heating chamber 301, which can be representative of an average temperature of the fluid within the low fluid capacity heating chamber 301. The temperature of the fluid within the low fluid capacity heating chamber 301 may typically be highest near the heat pump 320 and lowest near the fluid inlet 302. Therefore, the temperature sensor 308a can be positioned in a location that best represents the average temperature of the fluid, which can be useful to ensure the water is being heated to the proper temperature while water is or is not flowing through the water heater 300. Another temperature sensor 308b can be installed downstream of the low fluid capacity heating chamber 301 (e.g., at fluid outlet 304) and can be configured to monitor the temperature of the water exiting the low fluid capacity heating chamber 301, which can be useful to ensure the water is being heated to the proper temperature while water is being drawn through the system.

The temperature sensor(s) 308a, 308b can be any type of sensor capable of measuring temperature of a fluid and providing temperature data indicative of the fluid temperature to the controller 330. For example, the temperature sensor(s) 308a, 308b can be thermocouples, resistor temperature detectors, thermistors, infrared sensors, semiconductors, or any other type of sensors which would be appropriate for a given use or application. All temperature sensors of the system can be the same type of temperature sensor, or the system can include different types of temperature sensors. For example, temperature sensor 308a can be a thermocouple and temperature sensor 308b can be a thermistor. One skilled in the art will appreciate that the type, location, and number of temperature sensors can vary depending on the application. Any of these aforementioned sensors (or any other sensors not described herein) may also be installed within the heating chamber 301 (or any in other locations) as well.

The heat pump 320 can be controlled by a controller 330. The controller 330 can be a computing device configured to receive data, determine actions based on the received data, and output a control signal instructing one or more components of the system to perform one or more actions. Although shown in FIG. 3 as being mounted to the low fluid capacity heating chamber 301, one of skill in the art will understand that the controller 330 can be installed in any location, provided the controller 330 is in communication with at least some of the components of the system. This can include installation in or on an enclosure including one or more of the other components depicted in FIG. 3 or installation at a remote location physically separated from the components shown in FIG. 3. Furthermore, the controller 330 can be configured to send and receive wireless or wired signals; the controller 330 can be configured to send and receive analog or digital signals. The wireless signals can include Bluetooth™, BLE, WiFi™, ZigBee™, infrared, microwave radio, or any other type of wireless communication as may be appropriate for the particular application. The hard-wired signal can include any directly wired connection between the controller and the other components. For example, the controller 330 can have a hard-wired 320-volt connection to the heat pump 320 which directly energizes the heat pump. Alternatively, the components can be powered directly and receive control instructions from the controller 330 via a digital connection. The digital connection can include a connection such as an Ethernet or a serial connection and can utilize any appropriate communication protocol for the application such as Modbus, fieldbus, PROFIBUS, SafetyBus p, Ethernet/IP, or any other appropriate communication protocol for the application. Furthermore, the controller 330 can utilize a combination of wireless, hard-wired, and digital communication signals to communicate with and control the various components. One of skill in the art will appreciate that the above configurations are given merely as non-limiting examples and the actual configuration may vary depending on the application. Further details about the hardware and/or software elements of the controller 330 are provided with respect to FIG. 5, which is described in further detail below.

As depicted in FIG. 3, the controller 330 can be configured to receive data from the flow sensor 306 and one or more temperature sensors 308a, 308b. The controller 330 can be configured to engage the heat pump 320 and other components only when necessary, which can reduce the amount of power required to operate the system over a given period of time (e.g., a year). For example, the controller 330 can receive flow data from the flow sensor 306, determine whether the flow data indicates a positive flow rate, and activate the heat pump 320 if the fluid in the system has begun to flow. Alternatively or in addition, the controller 330 can receive temperature data from a temperature sensor 308a, 308b, determine whether the temperature data indicates a temperature that is less than a predetermined temperature setting, and activate the heat pump 320 if the detected temperature is less than the predetermined temperature setting (a “low temperature”). The controller 330 can determine the detected temperature is a low temperature based on one, some, or all of the temperature sensors 308a, 308b of the heat pump water heater 300, which can correspond to the detected water temperatures at multiple positions throughout the heat pump water heater 300. For example, the controller 330 can be configured to engage the heat pump 320 if any single temperature sensor 308a, 308b detects a low temperature. As another example, the controller 330 can be configured to engage the heat pump 320 only if all temperature sensors 308a, 308b detect a low temperature. As yet another example, the controller 330 can be configured to engage the heat pump 320 if a predetermined number (e.g., a majority) of temperature sensors 308a, 308b detect a low temperature. As yet another example, the controller 330 can be configured to engage the heat pump if a predetermined combination of temperature sensors 308a, 308b detect a low temperature. That is, the controller 330 can be configured to weigh data from a given temperature sensor more heavily than data from another temperature sensor, based on the location, type, accuracy, or other aspect of the temperature sensors.

The controller 330 can be configured to receive temperature data from a temperature sensor 308a, 308b and flow data from a flow sensor 306 and can determine whether the fluid can be maintained at the predetermined temperature for a predetermined amount of time based on the current temperature, flow rate, and/or output of the heat pump 320. This can enable the controller 330 to, for example, adjust the performance of the heat pump 320 to improve the efficiency of the system and/or prevent damage to the heat pump 320 or other components. Thus, if the heat pump 320 is a two-stage or variable capacity heat pump, the controller 330 can adjust the control signal to the heat pump 320 to vary its performance and the amount of heat transferred to the fluid. For example, if the controller 330 received flow data from the flow sensor 306 that indicated the fluid was flowing at a rate of 1.5 gallons per minute and received data from a temperature sensor 308b indicating that the current temperature of the fluid downstream of the low fluid capacity heating chamber 301 was 120° F., the controller 330 could determine whether the fluid could be maintained at a predetermined temperature setting for a predetermined amount of time (e.g., 1 minute, 2 minutes, 3 minutes, 5 minutes) based on the flow rate data (e.g., 1.5 gal/min), the temperature data (e.g., 120° F.), and/or known performance capabilities of the heat pump 320. If the controller 330 determines that the current heat pump 320 output would be inadequate to maintain the water temperature at the predetermined temperature setting, the controller 330 can transmit a control signal to the heat pump 320 indicating that the heat pump 320 should operate at a higher output (or a control signal instructing the heat pump 320 to disengage if the controller 320 determines that operation at a higher output would damage the heat pump 320 or other components of the heat pump water heater 300).

The controller 330 can be configured to monitor temperature data from a temperature sensor 308a to ensure the temperature of the fluid inside the low fluid capacity heating chamber 301 is maintained at a predetermined temperature setting even when no fluid is flowing. Accordingly, the controller 330 can be configured to ensure the water inside the low fluid capacity heating chamber 301 is heated and ready for use. By pre-heating water, the system can provide the user with a source of immediately available heated water, which can provide additional time for the heat pump water heater 300 to heat incoming water for further use.

As briefly discussed above, the controller 330 can be configured to determine actions based on data received from the flow sensor 306 and/or the temperature sensor(s) 308a, 308b. The controller 330 can be configured to maintain the temperature of fluid in the low fluid capacity heating chamber within a predetermined temperature range. For example, the predetermined temperature range can be from approximately 105° F. to approximately 135° F. When the temperature of the fluid falls below the lower endpoint of the predetermined temperature range (e.g., approximately 105° F.), the controller 330 can be configured to send a control signal to the heat pump 320 to energize the heat pump 320 and raise the temperature of the fluid. The control 330 can instruct the heat pump 320 to raise the temperature of the fluid until a predetermined fluid temperature is reached, such as a midpoint value between the endpoints of the predetermined temperature range (e.g., approximately 120° F. in the immediate example). Similarly, when the temperature of the fluid rises above the upper endpoint of the predetermined temperature range (e.g., approximately 135° F.), the controller 330 can send a control signal to the heat pump 320 to de-energize the heat pump and cease adding heat to the fluid. The controller 330 can instruct the heat pump 320 to cease adding heat to the fluid until a predetermined fluid temperature is reached, such as a midpoint value between the endpoints of the predetermined temperature range (e.g., approximately 120° F.).

As another example, the controller 330 can be configured to maintain the fluid in the low fluid capacity heating chamber within a smaller temperature range to ensure the water is closer to a desired temperature value when demanded. For example, the predetermined temperature range can be from approximately 123° F. to approximately 127° F., and the predetermined temperature range can correspond to a target temperature value of approximately 125° F. When the temperature of the fluid falls below 123° F., the controller 330 can send a control signal to the heat pump 320 to energize the heat pump 320 and raise the temperature of the fluid. Similarly, when the temperature of the fluid rises above 127° F., the controller 330 can send a control signal to the heat pump 320 to de-energize the heat pump and cease adding heat to the fluid. The given example temperature ranges are merely for illustration and can vary depending on the given application.

Furthermore, the controller 330 can be configured to determine and instruct multiple actions on the received temperature data and the received flow data. For example, the controller 330 can be configured to maintain the fluid within the low fluid capacity heating chamber 301 between 115° F. to 126° F. when water is not flowing and between 124° F. to 130° F. when the water is flowing. One of skill in the art will understand that these temperature ranges and instructions provided by the controller 330 are offered merely as example and that the actual configuration can be varied depending on the application.

FIG. 3 also depicts an optional ventilation system 329, which can be used to cool certain components of the heat pump 320. The ventilation system 329 can be installed directly on the heat pump water heater 300 or it can be installed nearby to facilitate cooling. For example, the ventilation system 329 can be installed on a door or wall of a housing in or on which the heat pump water heater 300 is installed (e.g., on the wall or door of the cupboard below a sink where the heat pump water heater 300 is installed). The ventilation system 329 can be configured to operate continuously, while the heat pump 320 is operating, once the fluid temperature has reached a predetermined temperature setting, or any combination thereof. The ventilation system 329 can be controlled by the controller 330 or can be controlled by a dedicated control system separate from the controller 330. If the ventilation system 329 has its own controller, the ventilation system's 329 controller can be in communication with the controller 330 (e.g., to receive temperature data or an indication that the heat pump 320 is engaged). Furthermore, the ventilation system 329 can be an active ventilation system, such as a mechanical fan, or a passive venting system, such as a vent or louver.

In one or more embodiments, the heat pump water heater 300 may also include one or more supplemental heat sources (e.g., supplemental heat source 350 and 352), which can be used to supply additional heat to the fluid. The supplemental heat sources 350 and/or 352 can provide increased precision of temperature control as compared to other examples; however, the inclusion of a supplemental heat source can also increase the complexity and overall cost of the system. Although FIG. 3 shows two supplemental heat sources 350 and 352, it is contemplated that supplemental heat can be added to the fluid by use of only one supplemental heat source or multiple supplemental heat sources depending on the particular application. The supplemental heat sources 350 and/or 352 can be any form of supplemental heat source as would be appropriate for the particular application. For example, the supplemental heat sources 350 and/or 352 can be electrical resistive heating elements, propane burners, natural gas burners, solar thermal heating, or any other appropriate type of supplemental heat source for the application. The supplemental heat sources 350 and 352, if both are installed in the system together, can be the same type of heat source or can be different types of heat sources. For example, supplemental heat source 350 can be a natural gas burner while supplemental heat source 352 can be an electrical resistive heating element.

In an example system, a supplemental heat source 350 can be positioned and configured to heat the fluid exiting the mixing valve 309. For example, in response to determining that the temperature of the fluid exiting the mixing valve is less than the predetermined temperature setting, the controller 330 can output instructions to the supplemental heat source 350 to transfer heat to the fluid. As another example, the controller 330 can output instructions to the supplemental heat source 352 to transfer heat to the fluid exiting the heating chamber 301 and entering the mixing valve 309 in response to determining that the fluid exiting the heating chamber 301 is at a low temperature. As yet another example, the controller 330 can determine that the fluid temperature will fall below a predetermined temperature setting based on the current flow rate, current fluid temperature, and/or heat pump 320 capabilities, and in response to so determining, the controller 330 can output instructions to one or more supplemental heat source(s) 350, 352 to transfer heat to the fluid. The predetermined temperature setting that is used to determine whether to engage or utilize the supplemental heat source(s) 350, 352 can be the same or a different predetermined temperature setting that is used to determine whether to utilize the heat pump 320. The supplemental heat source(s) 350, 352 can be used in an heat pump water heater 300 whether or not the water heater 300 includes a mixing valve 309.

Furthermore, it is contemplated that the supplemental heat source(s) 350, 352 can be controlled by the controller 330 or by a separate controller (e.g., a controller dedicated to control of one or more supplemental heat source(s) 350, 352). If the supplemental heat source(s) 350, 352 have a dedicated controller, the dedicated supplemental heat source controller can be in communication with the controller 330 or other components of the heat pump water heater 300.

The water heater 300 may also include electrical heating elements (for example, electrical heating element 360, electrical heating element 362, or any other electrical heating element described herein) within the tank 301. For example, the electrical heating element 360 may be the same as booster heating system 210 and the electrical heating element 362 may be the same as primary heating system 208. The electrical heating elements 360 and 362 may exist in addition to the supplemental heat sources 350 and 352 or may be alternatives to the supplemental heat sources 350 and 352.

As described above, in one or more embodiments, the electrical heating element 360 may be a 7 kW heating element and the electrical heating element 362 may be a 4.5 kW heating element. Initially, during an immediate demand scenario (also referred to as a high demand scenario herein), the 7 kW electrical heating element may be used to draw the maximum amount of current from the power source to which the electrical heating elements are electrically connected. If the immediate demand scenario necessitates the use of the electrical heating element 360 for more than a threshold period of time (for example, three hours per the regulations or any other designated amount of time), then the water heater may deactivate the 7 kW heating element and may instead use the 4.5 kW heating element that draws less than the maximum amount of current from the power source. These values are merely used for exemplary purposes and heating elements of other power ratings may also be used.

FIG. 4 illustrates an example heat pump water heater 400 with a wrap around condenser 411. In one or more embodiments, the water heater 400 may operate with the circuit 200 of FIG. 2 and in a similar manner to the operation described in FIG. 3 (for example, to alternate between the primary heating system and the booster heating system as needed based on the detected hot water demand, etc.).

In one or more embodiments, the water heater 400 may include a first electrical heating element 406 disposed in a top portion of the tank 401 and a second electrical heating element 408 disposed in a bottom portion of the tank 401. In some instances, the first electrical heating element 406 may specifically be positioned proximate to the fluid outlet 404 of the tank 401 (for example, the outlet of the tank 401 via which heated water is routed out of the water heater 400 and towards the load that is demanding the heated water). However, the first and second electrical heating elements 406, 408 may also be disposed at any other locations in the tank 401. Additionally, there may be any other number of electrical heating elements as well. For example, there may be a single electrical heating element, three electrical heating elements, four electrical heating elements, etc.

Referring now to FIG. 5, a schematic block diagram of one or more illustrative controller(s) 500 is shown. The controller(s) 500 may include any suitable computing device including, but not limited to, a controller (e.g., any of the controllers described herein, such as controller 326, etc.), etc.

The controller(s) 500 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. Further, such network(s) may have any suitable communication range associated therewith and may include, for example, global networks (e.g., the Internet), metropolitan area networks (MANs), wide area networks (WANs), local area networks (LANs), or personal area networks (PANs). In addition, such network(s) may include communication links and associated networking devices (e.g., link-layer switches, routers, etc.) for transmitting network traffic over any suitable type of medium including, but not limited to, coaxial cable, twisted-pair wire (e.g., twisted-pair copper wire), optical fiber, a hybrid fiber-coaxial (HFC) medium, a microwave medium, a radio frequency communication medium, a satellite communication medium, or any combination thereof.

In an illustrative configuration, the controller(s) 500 may include one or more processors (processor(s)) 502, one or more memory devices 504 (generically referred to herein as memory 504), one or more input/output (I/O) interfaces 506, one or more network interfaces 508, one or more sensors or sensor interfaces 530, one or more transceivers 532, one or more optional speakers 514, one or more optional microphones 516, and data storage 520. The controller(s) 500 may further include one or more buses 518 that functionally couple various components of the controller(s) 500. The controller(s) 500 may further include one or more antenna(e) 534 that may include, without limitation, a cellular antenna for transmitting or receiving signals to/from a cellular network infrastructure, an antenna for transmitting or receiving WiFi 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, a Near Field Communication (NFC) antenna for transmitting or receiving NFC signals, and so forth. These various components will be described in more detail hereinafter.

The bus(es) 518 may include at least one of a system bus, a memory bus, an address bus, or a message bus, and may permit the exchange of information (e.g., data (including computer-executable code), signaling, etc.) between various components of the controller(s) 500. The bus(es) 518 may include, without limitation, a memory bus or a memory controller, a peripheral bus, an accelerated graphics port, and so forth. The bus(es) 518 may be associated with any suitable bus architecture including, without limitation, an Industry Standard Architecture (ISA), a Micro Channel Architecture (MCA), an Enhanced ISA (EISA), a Video Electronics Standards Association (VESA) architecture, an Accelerated Graphics Port (AGP) architecture, a Peripheral Component Interconnect (PCI) architecture, a PCI-Express architecture, a Personal Computer Memory Card International Association (PCMCIA) architecture, a Universal Serial Bus (USB) architecture, and so forth.

The memory 504 of the controller(s) 500 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 certain example embodiments, volatile memory may enable faster read/write access than non-volatile memory. However, in certain other example embodiments, certain types of non-volatile memory (e.g., FRAM) may enable faster read/write access than certain types of volatile memory.

In various implementations, the memory 504 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. The memory 504 may include main memory as well as various forms of cache memory such as instruction cache(s), data cache(s), translation lookaside buffer(s) (TLBs), and so forth. Further, cache memory such as a data cache may be a multi-level cache organized as a hierarchy of one or more cache levels (L1, L2, etc.).

The data storage 520 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 520 may provide non-volatile storage of computer-executable instructions and other data. The memory 504 and the data storage 520, removable and/or non-removable, are examples of computer-readable storage media (CRSM) as that term is used herein.

The data storage 520 may store computer-executable code, instructions, or the like that may be loadable into the memory 504 and executable by the processor(s) 502 to cause the processor(s) 502 to perform or initiate various operations. The data storage 520 may additionally store data that may be copied to the memory 504 for use by the processor(s) 502 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) 502 may be stored initially in the memory 504, and may ultimately be copied to the data storage 520 for non-volatile storage.

More specifically, the data storage 520 may store one or more operating systems (O/S) 522; one or more database management systems (DBMSs) 524; and one or more program module(s), applications, engines, computer-executable code, scripts, or the like such as, for example, one or more data management module(s) 526, one or more data analysis module(s) 528, and/or one or more OBD module(s) 530. Some or all of these module(s) may be sub-module(s). Any of the components depicted as being stored in the data storage 520 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 504 for execution by one or more of the processor(s) 502. Any of the components depicted as being stored in the data storage 520 may support functionality described in reference to corresponding components named earlier in this disclosure.

The data storage 520 may further store various types of data utilized by the components of the controller(s) 500. Any data stored in the data storage 520 may be loaded into the memory 504 for use by the processor(s) 502 in executing computer-executable code. In addition, any data depicted as being stored in the data storage 520 may potentially be stored in one or more datastore(s) and may be accessed via the DBMS 524 and loaded in the memory 504 for use by the processor(s) 502 in executing computer-executable code. The datastore(s) may include, but are 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.

The processor(s) 502 may be configured to access the memory 504 and execute the computer-executable instructions loaded therein. For example, the processor(s) 502 may be configured to execute the computer-executable instructions of the various program module(s), applications, engines, or the like of the controller(s) 500 to cause or facilitate various operations to be performed in accordance with one or more embodiments of the disclosure. The processor(s) 502 may include any suitable processing unit capable of accepting data as input, processing the input data in accordance with stored computer-executable instructions, and generating output data. The processor(s) 502 may include any type of suitable processing unit including, but not limited to, a central processing unit, a microprocessor, a reduced instruction set computer (RISC) microprocessor, a complex instruction set computer (CISC) microprocessor, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a system-on-a-chip (SoC), a digital signal processor (DSP), and so forth. Further, the processor(s) 502 may have any suitable microarchitecture design that includes any number of constituent components such as, for example, registers, multiplexers, arithmetic logic units, cache controllers for controlling read/write operations to cache memory, branch predictors, or the like. The microarchitecture design of the processor(s) 502 may be capable of supporting any of a variety of instruction sets.

Referring now to functionality supported by the various program module(s) depicted in FIG. 6, the module(s) 526 may include computer-executable instructions, code, or the like that responsive to execution by one or more of the processor(s) 502 may perform any of the functions associated with the control of a heat pump and/or any electrical heating element as described herein.

Referring now to other illustrative components depicted as being stored in the data storage 520, the O/S 522 may be loaded from the data storage 520 into the memory 504 and may provide an interface between other application software executing on the controller(s) 500 and the hardware resources of the controller(s) 500. More specifically, the O/S 522 may include a set of computer-executable instructions for managing hardware resources of the controller(s) 500 and for providing common services to other application programs (e.g., managing memory allocation among various application programs). The O/S 522 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.

The DBMS 524 may be loaded into the memory 504 and may support functionality for accessing, retrieving, storing, and/or manipulating data stored in the memory 504 and/or data stored in the data storage 520. The DBMS 524 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 524 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. In those example embodiments in which the controller(s) 500 is a mobile device, the DBMS 524 may be any suitable lightweight DBMS optimized for performance on a mobile device.

Referring now to other illustrative components of the controller(s) 500, the input/output (I/O) interface(s) 506 may facilitate the receipt of input information by the controller(s) 500 from one or more I/O devices as well as the output of information from the controller(s) 500 to 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; a haptic unit; and so forth. Any of these components may be integrated into the controller(s) 500 or may be separate. The I/O devices may further include, for example, any number of peripheral devices such as data storage devices, printing devices, and so forth.

The I/O interface(s) 506 may also include an interface for an external peripheral device connection such as a universal serial bus (USB), FireWire, Thunderbolt, Ethernet port or other connection protocol that may connect to one or more networks. The I/O interface(s) 506 may also include a connection to one or more of the antenna(e) 534 to connect to one or more networks via a wireless local area network (WLAN) (such as WiFi) radio, Bluetooth, ZigBee, and/or a wireless network radio, such as a radio capable of communication with a wireless communication network such as a Long Term Evolution (LTE) network, WiMAX network, 3G network, etc.

The controller(s) 500 may further include one or more network interface(s) 508 via which the controller(s) 500 may communicate with any of a variety of other systems, platforms, networks, devices, and so forth. The network interface(s) 508 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 networks.

The antenna(e) 534 may include any suitable type of antenna depending, for example, on the communications protocols used to transmit or receive signals via the antenna(e) 534. Non-limiting examples of suitable antennae may include directional antennae, non-directional antennae, dipole antennae, folded dipole antennae, patch antennae, multiple-input multiple-output (MIMO) antennae, or the like. The antenna(e) 534 may be communicatively coupled to one or more transceivers 532 or radio components to which or from which signals may be transmitted or received.

The transceiver(s) 532 may include any suitable radio component(s) for—in cooperation with the antenna(e) 534—transmitting or receiving radio frequency (RF) signals in the bandwidth and/or channels corresponding to the communications protocols utilized by the controller(s) 500 to communicate with other devices. The transceiver(s) 532 may include hardware, software, and/or firmware for modulating, transmitting, or receiving—potentially in cooperation with any of antenna(e) 534—communications signals according to any of the communications protocols discussed above including, but not limited to, one or more WiFi and/or WiFi direct protocols, as standardized by the IEEE 802.31 standards, one or more non-Wi-Fi protocols, or one or more cellular communications protocols or standards. The transceiver(s) 532 may further include hardware, firmware, or software for receiving GNSS signals. The transceiver(s) 532 may include any known receiver and baseband suitable for communicating via the communications protocols utilized by the controller(s) 500. The transceiver(s) 532 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.

The sensor(s)/sensor interface(s) 530 may include or may be capable of interfacing with any suitable type of sensing device such as, for example, pressure sensors, moisture sensors, temperature sensors, etc.

It should further be appreciated that the controller(s) 500 may include alternate and/or additional hardware, software, or firmware components beyond those described or depicted without departing from the scope of the disclosure. More particularly, it should be appreciated that software, firmware, or hardware components depicted as forming part of the controller(s) 500 are merely illustrative and that some components may not be present or additional components may be provided in various embodiments. While various illustrative program module(s) have been depicted and described as software module(s) stored in the data storage 520, it should be appreciated that functionality described as being supported by the program module(s) may be enabled by any combination of hardware, software, and/or firmware. It should further be appreciated that each of the above-mentioned module(s) may, in various embodiments, represent a logical partitioning of supported functionality. This logical partitioning is depicted for ease of explanation of the functionality and may not be representative of the structure of software, hardware, and/or firmware for implementing the functionality. Accordingly, it should be appreciated that functionality described as being provided by a particular module may, in various embodiments, be provided at least in part by one or more other module(s). Further, one or more depicted module(s) may not be present in certain embodiments, while in other embodiments, additional module(s) not depicted may be present and may support at least a portion of the described functionality and/or additional functionality. Moreover, while certain module(s) may be depicted and described as sub-module(s) of another module, in certain embodiments, such module(s) may be provided as independent module(s) or as sub-module(s) of other module(s).

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.

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.

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.

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.

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.

Claims

1. A heat pump water heater comprising:

a fluid inlet;

a fluid outlet;

a heating chamber disposed in fluid communication between the fluid inlet and the fluid outlet, the heating chamber configured to hold a fluid;

a heat pump for heating the fluid;

a first heating element for supplementing the heat pump in heating the fluid, the first heating element configured to draw less than a maximum current from a power source;

a second heating element for heating the fluid, the second heating element configured to draw the maximum current from the power source; and

a controller configured to: receive an indication of demand for hot water; determine that a current temperature of the fluid in the heating chamber is less than a temperature setpoint; activate the second heating element to heat the fluid in the heating chamber; determine that a threshold amount of time has passed since activating the second heating element; and disable, based on the determination that the threshold amount of time has passed, the second heating element.

2. The heat pump water heater of claim 1, wherein the first heating element is disposed below the second heating element within the water heater.

3. The heat pump water heater of claim 2, wherein the second heating element is disposed at the fluid outlet of the water heater.

4. The heat pump water heater of claim 1, wherein the threshold amount of time is three hours.

5. The heat pump water heater of claim 1, further comprising a relay with an input that is electrically connected to the power source and one or more outputs that are electrically connected to the first heating element and the second heating element.

6. The heat pump water heater of claim 1, wherein the second heating element is a 7 kW heating element.

7. The heat pump water heater of claim 1, wherein the first heating element is a 4.5 kW heating element.

8. A method for providing hot water on-demand, the method comprising:

receive, by a controller of a water heater, an indication of demand for hot water to be supplied by the water heater, wherein the water heater comprises a heat pump for heating the water, a first heating element for supplementing the heat pump in heating the water, the first heating element configured to draw less than a maximum current from a power source, and a second heating element for heating the water, the second heating element configured to draw the maximum current from the power source;

determine, by the controller, that a current temperature of the water in a heating chamber of the water heater is less than a temperature setpoint;

activate, by the controller, the second heating element to heat the water in the heating chamber;

determine, by the controller, that a threshold amount of time has passed since activating the second heating element; and

disable, by the controller and based on the determination that the threshold amount of time has passed, the second heating element.

9. The method of claim 8, wherein the first heating element is disposed below the second heating element within the water heater.

10. The method of claim 9, wherein the second heating element is disposed at a fluid outlet of the water heater.

11. The method of claim 8, wherein the threshold amount of time is three hours.

12. The method of claim 8, further comprising a relay with an input that is electrically connected to the power source and one or more outputs that are electrically connected to the first heating element and the second heating element.

13. The method of claim 8, wherein the second heating element is a 7 kW heating element.

14. The method of claim 8, wherein the first heating element is a 4.5 kW heating element.

15. A water heater comprising:

a heating chamber configured to hold a fluid;

a heat pump for heating the fluid;

a first heating element for supplementing the heat pump in heating the fluid, the first heating element configured to draw less than a maximum current from a power source;

a second heating element for heating the fluid, the second heating element configured to draw the maximum current from the power source; and

a controller configured to: receive an indication of demand for hot water; determine that a current temperature of the fluid in the heating chamber is less than a temperature setpoint; activate the second heating element to heat the fluid in the heating chamber; determine that a threshold amount of time has passed since activating the second heating element; and disable, based on the determination that the threshold amount of time has passed, the second heating element.

16. The water heater of claim 15, wherein the first heating element is disposed below the second heating element within the water heater.

17. The water heater of claim 16, wherein the second heating element is disposed at a fluid outlet of the water heater.

18. The water heater of claim 15, wherein the threshold amount of time is three hours.

19. The water heater of claim 15, further comprising a relay with an input that is electrically connected to the power source and one or more outputs that are electrically connected to the first heating element and the second heating element.

20. The water heater of claim 15, wherein the second heating element is a 7 kW heating element, and wherein the first heating element is a 4.5 kW heating element.