Method, system and apparatus for supporting reduction of using amount of energy and water

Abstract

To provide a method for controlling the supply of heated water to a plurality of water outlets remote from a heating appliance.SOLUTION: A method includes: a step of detecting demands for water from a first water outlet, identifying a demand that is likely to be relevant, and setting an associated first target water temperature value; a step of similarly resetting a second target water temperature value from a second water outlet, in which identification of the demands associated with the first and second outlets is based on their respective flow characteristics; and a step of controlling the mixing of heated water and water from the heating appliance to provide water at the first or second target water temperature value. The heating appliance includes an energy storage facility for storing energy, a heat exchanger connected between a hot water system and a heat pump, and a system controller, and the system controller detects opening of any of a plurality of hot water outlets and determines whether to provide a start signal to the heat pump based on a detected hot water flow rate and the state of the energy storage facility.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to methods and apparatus for facilities including building hot water supply systems that assist in reducing energy and water usage.

[0002] background

[0003] There is a global shortage of drinking water. Water shortages are now commonly reported around the world, and while one might think that such issues only affect "hot" countries or continents, this is no longer the case. The European Environment Agency reports that water scarcity and water stress are issues affecting millions of people worldwide, including over 100 million people in Europe. Approximately 88.2% of Europe's freshwater use (drinking and other uses) comes from rivers and groundwater, with the remainder coming from reservoirs (10.3%) and lakes (1.5%), making these sources highly vulnerable to threats posed by overexploitation, pollution, and climate change.

[0004] This has led to an urgent need to reduce domestic water use. On average, Europe provides 144 litres of freshwater per person per day for domestic use, but much of this water is wasted through carelessness and poor choice of taps and shower fixtures.

[0005] Alongside the need to reduce water consumption, there is also a need to reduce domestic energy consumption, given that (at least in Europe) around 75% of heating and cooling is still generated from fossil fuels, while only 22% is generated from renewable energy.

[0006] According to Directive 2012 / 27 / EU, buildings account for 40% of the European Union's final energy consumption and 36% of its CO2 emissions. A 2016 EU Commission report, "Mapping and Analysis of Current and Future (2020-2030) Heating / Cooling Fuel Deployment (Fossil Fuels / Renewables)," concluded that space heating and hot water alone account for 79% of final energy use (192.5 Mtoe) in EU homes. The EU Commission also noted that "Eurostat's 2019 figures show that approximately 75% of heating and cooling is still generated from fossil fuels, while only 22% is generated from renewable energy sources. To achieve EU climate and energy targets, the heating and cooling sector must significantly reduce its energy consumption and cut fossil fuel use. Heat pumps (which draw energy from the air, ground, or water) have been identified as a potentially important contributor to addressing this issue."

[0007] Many countries have policies and pressures to reduce carbon dioxide emissions. For example, in the UK, the UK government published a white paper on "Future Home Standards" in 2020, proposing to reduce carbon emissions from new homes by 75-80% compared to existing levels by 2025. Furthermore, in early 2019, it was announced that gas boilers would be banned from being installed in new homes from 2025. At the time of filing, it was reported that 78% of all energy used to heat buildings in the UK comes from gas, and 12% from electricity.

[0008] There are many small, gas-fired, centrally heated properties in the UK with two or three bedrooms or less. Most of these properties use what's known as a combined boiler, which acts as both an instantaneous hot water heater and a central heating boiler. Combined boilers are popular because they combine a small form factor, provide an instant source of more or less "unlimited" hot water (20-35 kW output), and do not require hot water storage. Such boilers can be purchased relatively inexpensively from reputable manufacturers. Their small form factor and ability to operate without a hot water storage tank generally means that even a small apartment or house—often wall-mounted—can accommodate such a boiler, and a new boiler can be installed in a single day's work by one person. Therefore, new combined gas boilers can be installed inexpensively. With new gas boilers soon to be banned, alternative heat sources must be provided to replace gas combined boilers. Furthermore, previously installed combined boilers will eventually need to be replaced with alternatives.

[0009] Heat pumps have been proposed as a potential solution to the need to reduce dependence on fossil fuels and cut CO2 emissions, but they are currently unsuitable for replacing gas-fired boilers in small domestic (and small commercial) premises for a number of technical, commercial, and practical reasons. They are typically very large, requiring a substantial unit outside the premises. Therefore, they cannot be easily retrofitted to premises with typical combined boilers. Units capable of providing equivalent output to a typical gas boiler are currently expensive and can require significant electrical demand. Not only do the units themselves cost multiples of the equivalent gas-fired equivalent, but their size and complexity mean that the installations are technically complex and therefore expensive. A storage tank for the hot water is also required, which is a further factor preventing the use of heat pumps in small households. A further technical issue is that heat pumps tend to require a significant amount of time to begin generating heat on demand—perhaps 30 seconds for self-checking, followed by some time to heat up—leading to a delay of a minute or more between the request for hot water and its delivery. For this reason, attempted renewable solutions using heat pumps and / or solar power are typically applicable to large properties that have space for hot water storage tanks (with their associated space demands, heat losses and risk of Legionella).

[0010] A significant component of domestic energy consumption comes from domestic hot water use, both in terms of the amount of hot water used and the energy wasted from overheating domestic hot water. Hot water waste is, of course, also a significant contributor to the more general problem of water waste, which also needs to be addressed if humanity is to have a sustainable future. Aspects of the present disclosure relate to methods and facilities that can help reduce hot water use and thus contribute to reducing both energy and water use.

[0011] overview

[0012] According to a first aspect, there is provided a method for controlling the supply of heated water from a source including a heating appliance to a plurality of water outlets remote from the heating appliance, the method comprising the steps of: detecting a demand for water from a first water outlet, identifying a likely demand associated with the first water outlet, and setting a first target water temperature value associated with the first water outlet to a target water temperature to which the water is to be supplied; detecting a demand for water from a second water outlet, identifying a likely demand associated with the second water outlet, and resetting the target water temperature to a second target water temperature value associated with the second water outlet, wherein the demands are associated with the outlets based on flow characteristics, which may be detected based on measured pressure changes and / or measured flow.

[0013] The method may further include controlling the mixing of heated water from the heating appliance with water at different temperatures to provide a supply of water at the first or second target water temperature value.

[0014] The method may further include controlling the heating appliance to adjust the temperature at which the heated water is supplied from the heating appliance.

[0015] The flow characteristics may include at least one of a maximum flow rate and / or a rate of change of flow to a predetermined flow rate.

[0016] If desired, identifying the demand may include obtaining additional information related to the outlet, such as, for example, an electrical demand or occupancy signal associated with the outlet, and / or a sensor or transducer associated with the location of the outlet.

[0017] The method may further include detecting potential demand associated with two or more outlets and setting the target water temperature to a third target water temperature value. The third target water temperature value may be the lowest target water temperature value associated with the identified potential water outlets. The third target water temperature value may be an intermediate temperature between the target water temperature values ​​of the identified potential water outlets.

[0018] The heating appliance can be part of a domestic hot water supply system, and the heating appliance can include an energy storage facility including a quantity of phase change material for storing energy in the form of latent heat, a heat exchanger coupled between the hot water system and a heat pump, and a system controller. The system controller is configured to receive information from a flow measurement device and information regarding a status of the energy storage facility, and the system controller is configured to sense opening of any of a plurality of controllable hot water outlets and determine whether to provide a start signal to the heat pump based on the sensed hot water flow rate and the status of the energy storage facility. The system controller can be configured to receive status information from the heat pump and to use the heat pump status information when determining whether to provide a start signal to the heat pump.

[0019] According to a second aspect, there is provided a domestic hot water supply facility having a plurality of controllable hot water outlets, the facility including: a hot water source with an outlet having a controllable outlet temperature; a flow measurement device providing data relating to water flow between the hot water source and the plurality of controllable hot water outlets; a first temperature sensor detecting the outlet temperature; a memory storing parameters linking the flow data to an outlet identifier and associating each of the plurality of controllable hot water outlets with a respective target temperature; and a processor operably connected to the memory, the flow measurement device, and the first temperature sensor, the processor configured to: The system is configured to: determine which of the plurality of controllable hot water outlets has been opened based on the detected flow characteristics when one of the outlets has been opened, and then control the outlet temperature of the hot water source in accordance with the stored parameters for the determined one of the controllable hot water outlets based on the determination; and determine which of the plurality of controllable hot water outlets has been opened when another of the plurality of controllable hot water outlets has been opened, and control the outlet temperature of the hot water source in accordance with the stored parameters for the determined other of the controllable hot water outlets based on the determination. The flow characteristics may be detected based on the measured pressure and / or the measured flow.

[0020] The hot water supply facility can include an energy storage facility including a quantity of phase change material and a heat exchanger coupled between the hot water system and the heat pump, and a system controller, wherein the processor is configured to receive information from the flow measurement device and information regarding the status of the energy storage facility, sense the opening of any of a plurality of controllable hot water outlets, and determine whether to provide a start signal to the heat pump based on the sensed hot water flow rate and the status of the energy storage facility. The processor is configured to receive status information from the heat pump and use the heat pump status information in determining whether to provide a start signal to the heat pump.

[0021] The hot water supply facility may further include an instantaneous water heater in a flow path between the energy storage facility and the outlet of the hot water source, the instantaneous water heater being controlled by a processor. The processor may be configured to operate the instantaneous water heater only when the energy storage facility and the heat pump are unable to provide sufficient hot water. The processor may be configured to control the instantaneous water heater based on information about the state of the phase change material and the heat pump. The processor may include logic circuitry that manages the instantaneous water heater, the heat pump, and the use of energy from the phase change material to reduce energy consumption. The processor may also be configured to preferentially rely on the energy storage facility and then the heat pump to provide sufficient hot water.

[0022] According to a third aspect, a domestic water supply facility is provided, the domestic water supply facility including an instantaneous water heating appliance, a plurality of controllable water outlets remote from the appliance, a water supply line configured to supply heated water from the appliance to the plurality of controllable water outlets, at least one sensor for sensing a characteristic or condition of the water supply line, and a processor coupled to the at least one sensor. The processor is configured to: monitor the water supply line supplying the controllable water outlets using the at least one sensor; detect water demand from a first water outlet; identify demands possibly associated with the first water outlet based on the detected flow characteristics; set a first target water temperature associated with the first water outlet to a target water temperature at which the water is to be supplied; detect water demand from a second outlet of the plurality of outlets; identify demands possibly associated with the second water outlet based on the detected flow characteristics; and set a second target water temperature associated with the second outlet to a target water temperature at which the water is to be supplied. The flow characteristics may be detected based on measured pressure and / or measured flow. The one or more sensors may include a pressure sensor, preferably located between the appliance and the plurality of controllable water outlets, for sensing pressure in the water supply line. The one or more sensors may include a flow sensor, preferably located between the appliance and the plurality of controllable water outlets, for measuring flow in the water supply line. The heating appliance includes a valve for mixing supplied cold water and heated water, the valve being controlled by the processor. The heating appliance may include an energy storage facility including a phase change material, the energy storage facility being configured to store energy using the latent heat of the phase change material. The heating appliance may include a renewable heat source, preferably a heat pump, coupled to the processor. The renewable heat source may be configured to supply energy to the energy storage facility. The heating appliance may include an instantaneous water heater under control of the processor, the instantaneous water heater being arranged to receive energy from a networked energy supply. [Brief explanation of the drawings]

[0023] Embodiments of various aspects of the present disclosure will now be described, by way of example only, with reference to the drawings of the present disclosure. [Figure 1] FIG. 1 is a schematic diagram illustrating an in-building water supply facility according to one embodiment of the present disclosure. [Figure 2] FIG. 2 illustrates schematically a method for configuring a hot water supply facility with multiple controllable hot water outlets. [Figure 3] FIG. 3 is a schematic diagram illustrating a possible installation of a facility including a building hot water supply system according to one embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic diagram generally corresponding to FIG. 3 but showing more details of a possible configuration of a heating appliance according to one embodiment of the present disclosure. [Figure 5] FIG. 5 is a schematic diagram illustrating an energy bank including a phase change material and a heat exchanger coupled to a heat pump energy source, the energy bank including one or more sensors that provide measurement data indicative of the amount of energy stored as latent heat in the phase change material. [Figure 6] FIG. 6 is a high-level flowchart of a method carried out by a facility including an energy bank such as that of FIG. [Figure 7] FIG. 7 is a high level flow chart for another method performed by an energy bank such as that of FIG. [Figure 8] FIG. 8 is a flow chart of another method performed by an energy bank such as the method of FIG. [Figure 9] FIG. 9 is a flow chart of another method performed by an energy bank such as the method of FIG. [Figure 10] FIG. 10 is a schematic diagram illustrating a possible arrangement of components of an interface unit incorporating an energy bank according to one embodiment of the present disclosure. Detailed Description

[0024] To address domestic energy consumption, it is important to consider the energy used to provide hot water, which means considering not only the temperature of the water supplied or stored, but also the volume of hot water used. In many countries and regions recognized as having an abundance of freshwater, little attention has historically been paid to the amount of water used by households, largely reflected in the configuration of water supply systems and the flow rates of water outlets. It was not uncommon for bathtub faucets to flow more than 15 liters per minute, kitchen faucets more than 12 liters per minute, and even washbasin faucets more than 10 liters per minute. Shower outlets can flow more than 15 liters per minute, with about two-thirds of this typically coming from the heat supply.

[0025] Attitudes have changed somewhat over the past two decades, due to the recognition of water scarcity and the privatization of former public water suppliers, resulting in the introduction of domestic water meters and volumetric water billing. As a result, newer build homes tend to have taps and shower outlets with maximum flow rates that are about half to two-thirds that of historic homes. Nevertheless, not only are high-flow taps and showers still common in older dwellings, but even more modern outlets facilitate the use of more water than strictly necessary for washing hands, bathing, or showering. Consider a shower with a flow rate of 15 liters per minute.

[0026] A 12-minute shower uses 180 liters of water, of which approximately 100 to 110 liters are provided by the heat supply. The hot water supply temperature is often heated to a range of temperatures from below 10°C to 50-60°C, which is often obtained from much lower temperatures. Therefore, it can be seen that not only is a large amount of water used, but also a large amount of energy is used to heat that water.

[0027] Furthermore, although a hot water supply at a high temperature of 50-60°C has the advantage of reducing the risk of Legionella infection, there is a significant risk of burns at temperatures in this range.

[0028] Aspects of the present disclosure relate to a method and facility that allows a system controller to set the temperature of water supplied to an outlet of a hot water system, thereby allowing a target water supply temperature to be set for each of multiple outlets of the hot water system. The target water supply temperature is the temperature at which hot water is supplied from a hot water source. Furthermore, the method and apparatus of the present disclosure can adjust the temperature at which hot water is supplied from a hot water source when a second outlet is opened while hot water is being supplied from another outlet that has a different target water supply temperature than the second outlet. Aspects of the present disclosure also address how a hot water supply system can be mapped and how a target water supply temperature can be set for each of multiple outlets.

[0029] 1 schematically illustrates a hot water supply system 100 in a building (in this case, a residence) having a hot water supply 105 with a plurality of controllable water outlets (various faucets and showers, described in more detail below), at least one outlet 107 with a controllable outlet temperature, and, in a water flow path between the water supply 105 and the plurality of controllable water outlets, at least one first temperature sensor 109 for detecting the outlet temperature, at least one flow measurement device 110, and at least one flow regulator 115. A processor 140 is operably connected to the at least one flow measurement device 110 and the at least one flow regulator 115. The illustrated water supply system represents a residence having a master bathroom 121, a first en-suite shower room 122, a second en-suite shower room 123, a cloakroom 124, and a kitchen 125. The master bathroom and first en-suite shower room may be located on the first floor of the residence, while the cloakroom, second en-suite shower room, and kitchen may be located on another floor of the residence. In such a situation, it is advantageous to have two separate circuits 130 and 131 to supply water to the various outlets, as shown. While the two circuits 130 and 131 are shown fed from a single outlet 107 from the hot water supply, it will be understood that, along with a single temperature sensor 109, the two circuits 130 and 131 may each be fed from a different outlet 107, and the temperatures of the two outlets 107 may be separately adjustable, with each outlet 107 having its own associated temperature sensor 109. The temperature of the water at the outlets 107 may be adjusted by mixing cold water with hot water from a fixed or variable temperature source, or by controlling the energy input to a heat source, such as an electric heating element or gas-fired heater. Typically, even if multiple hot water circuits are provided between the hot water 105 supply and the hot water utility outlet, each circuit typically includes multiple hot water outlets supplied through a common pipe or conduit, such as a 22mm or 28mm outer diameter pipe. Embodiments of the present invention preferably monitor one or more flow characteristics to identify (determine) the outlet(s) responsible for the detected flow.

[0030] Hot water systems are described below that include a PCM energy storage facility, typically in combination with a heat pump, that stores energy as latent heat. In such systems, the hot water supply temperature can typically be adjusted by blending different proportions of chilled water from the chilled water supply. Sometimes, such systems can include an instantaneous heat source (e.g., an electric heating element) downstream of the PCM energy storage facility that is controlled by the system's processor. In such facilities, control of the hot water supply temperature can involve controlling the amount of energy provided to the instantaneous water heater, as well as by blending different proportions of chilled water from the chilled water supply.

[0031] The master bathroom 121 is shown as including a shower outlet 135, a bath faucet or tap 136, and a sink faucet 137. The en-suite shower rooms 122 and 123 also include a shower outlet 135 and a sink faucet 137. Conversely, the cloakroom includes a toilet (not shown) and a hand basin with faucet 138. Finally, the kitchen includes a sink with faucet 139.

[0032] The processor or system controller 140, along with associated memory 141, is coupled to at least one flow measurement device 110 and at least one flow regulator 115. It will be appreciated that each of the two circuits 130 and 131 includes a respective flow measurement device 110 and flow regulator 115. The processor is also optionally connected to one or more temperature sensors 143, one for each of the circuits 130 and 131. The processor may be associated with an energy bank, as previously described.

[0033] The processor may also be coupled to an RF transceiver 142 including at least one RF transmitter and at least one RF receiver for two-way communication via Wi-Fi, Bluetooth, etc., and preferably also to the Internet 144 for connection to a server or central station 145, and optionally to a cellular wireless network (LTE, UMTS, 4G, 5G, etc.). The RF transceiver 142 and / or connection to the Internet allow the processor 140 to communicate with a mobile device 150, which may be, for example, a smartphone or tablet, for use by a facility engineer in configuring (and optionally mapping) the building water supply facility. The mobile device 150 includes software, such as specific applications, that cooperate with corresponding software in the system controller 140 and potentially the server 145 to facilitate the configuration (and optionally mapping) method in accordance with an embodiment of the present invention, particularly to synchronize actions taken by the engineer with the system controller 140 / server 145 clock. The memory 141 includes code that enables the processor to execute a method for configuring (and optionally mapping) a building water supply plant processor, for example during the process of commissioning a new plant.

[0034] During the commissioning process, to configure the hot water supply facility 100, an engineer may be required to set up a temperature sensor directly below a specific hot water outlet, e.g., a specific faucet or shower outlet, and fully open the outlet at a specific moment. The system processor is configured to measure the flow, the difference between the outlet and supply temperature, the time delay, and preferably the outside air temperature (data provided by an external temperature sensor). This allows an algorithm (e.g., MLA) to calculate the heat loss through the distribution system, the distance between the outlet (faucet or shower outlet) and the hot water source, and finally, precisely adjust the outlet temperature at 107 to achieve the correct water temperature at the associated controllable outlet (e.g., faucet). For example, if there are children in the home, the maximum hot water temperature for all outlets except the kitchen sink may be limited to 40°C or 41°C, while if there is a toddler in the home, the maximum temperature may be limited to 37°C. Even if there are no children, the maximum temperature for all outlets except the kitchen sink may be set to 43°C, and the maximum temperature for the shower outlet may be set to 41°C.

[0035] The system may also be configured to limit hot water flow to some classes of water outlets (e.g., washbasins and sinks, and possibly showers), with different maximum flow rates set for each class of outlet and / or maximum specific flow rates set for specific outlets, with lower flow rates set for bathrooms used by children and cloakrooms, for example. The determination of maximum temperatures and flow rates may be based on rules established by the system supplier. We later discuss hot water supply systems using heat pumps and PCM-based energy storage, which benefit significantly from the imposition of temperature and flow control. This is because a heat pump sized for the heating needs of a modest one- to three-bedroom residence generally does not have the heating capacity to meet the household's instantaneous hot water demand without providing a large hot water storage tank. By managing hot water flow and temperature, it is possible to eliminate the need for hot water storage while minimizing the size of energy shortfalls that could otherwise be met. If the facility includes a PCM energy storage facility and a heat pump, the system supplier typically pre-programs the processor with appropriate values ​​for temperature and flow rate based on the outlet type and home configuration.

[0036] A database of temperatures and optionally flow rates based on outlet type and household configuration may also be made available via the internet to the system controller and updated from time to time. A user interface for the system controller may provide a means for occupants and / or service engineers to adjust various settings according to changes in household configuration, for example, adding the arrival of guests with infants, children or elderly or infirm individuals to allow the user to set a lower maximum temperature and / or flow rate.

[0037] 2 illustrates schematically such a method of configuring a hot water supply facility with multiple controllable hot water outlets (e.g., multiple faucets and one or more shower outlets). To improve the efficiency of energy use in the facility, the system's processor is used in conjunction with a portable temperature sensor 800 that is placed in turn under each outlet (although obviously multiple sensors may be used, not the same sensor for each outlet).

[0038] The installer may have an application on, for example, a smartphone or some other wireless transmit / receive unit (WTRU) that may receive instructions from the processor instructing the installer to open the associated faucet, preferably to its maximum opening as quickly as possible.

[0039] Thus, as shown in the plot of flow versus time in Figure 2, there is an initial delay (time T0-T1) due to the installer's reaction time before the flow through the outlet (since only one outlet is open at a time) and the flow through the hot water system goes from 0 to a maximum value at T1 (the maximum value may be different and is unique for each outlet in the hot water system). Alternatively, the installer can use the WTRU, or more typically an application on the WTRU, to notify the processor that the agreed / identified faucet is now open.

[0040] In either case, the processor also receives information from a temperature sensor 109 at the outlet 107 of the hot water source 105 with an outlet having a controllable outlet temperature. The portable temperature sensor 800 also preferably includes an internal clock (preferably synchronized to the processor's system time) and RF (e.g., Wi-Fi, Bluetooth, or IMS) capability for communicating time and temperature information to the remote processor 140. The temperature versus time plot in Figure 2 shows how the temperature sensed by the portable sensor 800 initially remains low and then rises to reach a stable maximum at time T2, some time after time T1. It can also be seen that the maximum detected temperature sensed by the portable sensor 800 (from time T1 to T3) is lower by ΔT than the temperature at the outlet 107 of the hot water source with controllable outlet temperature.

[0041] Temperature sensor 800 may be configured so that the data it collects (temperature versus time) is provided to system processor 140 only after an event, i.e., by a wired download process or using NFC, although this is generally less satisfactory than providing direct RF communication, as already explained.

[0042] While the possibility of regulating both flow rate and temperature for each of multiple outlets in a hot water supply system has been described above, it will be appreciated that the system may be configured to only set a target water supply temperature and not limit flow rate. Here, a configuration will be described in which target water supply temperatures are set for multiple outlets, but the flow rate is not necessarily adjusted by the system. In particular, this system, described with reference to FIG. 3 , will be used to illustrate a method according to one aspect of the present invention, which includes detecting a demand for water from a first water outlet, identifying a demand that may be associated with the first water outlet, and setting a first target water temperature value associated with the first outlet, the target water temperature at which the water will be delivered, and detecting a demand for water from a second water outlet, identifying a demand that may be associated with the second water outlet, and resetting the target water temperature at which the water will be delivered to a second target water temperature value associated with the second outlet.

[0043] 3 illustrates, in simplified form, a facility according to one embodiment of the present disclosure. The facility includes an instant water heating appliance 301 and at least two controllable water outlets 302 and 303 remote from appliance 301. The two outlets 302 and 303 may be in different rooms, as indicated by perimeters 350 and 351, and instant water heating appliance 301 may be located in yet another room.

[0044] The instant water heating appliance 301 will be described in more detail below with reference to Figure 4. However, to facilitate the explanation of the principles behind the method according to the first aspect of the invention, the appliance will be considered simply as a source of hot water.

[0045] A water supply 307, which may be a main cold water supply, is coupled to the heating appliance 301. Heated water emerging from the heating appliance 301 passes to a thermostatic mixing valve 309 through which it passes to reach the hot water supply illustrated by piping 360 and controllable outlets 302 and 303. (In practice, as shown in FIG. 1, there will typically be multiple controllable water outlets in multiple rooms, including bathtub faucets, shower faucets, hand basin faucets, and kitchen faucets, but these are omitted here for ease of explanation.) Mixing valve 309, which also receives a supply of cold water from supply 307, is coupled to and electronically controlled by a controller or processor 311 of the instant hot water heater appliance 301.

[0046] The processor 311 is also coupled to a first temperature sensor 312 in the flow path from the heating appliance 301 to the mixing valve 309, and to another 315 at an outlet of the mixing valve 309, which may be provided for sensing the temperature of the water from the water supply 307. Also coupled to the processor 311 is a flow transducer or pressure sensor 314 and a flow controller (valve) 316, both in the flow path from the heating appliance 301 to the mixing valve 309. A further flow or pressure sensor 317 coupled to the processor 311 may be provided in the hot water supply to the outlets (e.g., faucets) 302 and 303, for example proximate to each of the outlets 302 and 303.

[0047] Also shown in FIG. 3 is a light control or switch 362 for operating a light in the room, indicated by label 351. Processor 311 is configured to be supplied with information regarding the state of switch 362, either wirelessly as shown, or using a wired data feed; in either case, a CAN bus configuration can be used. In this way, processor 311 is provided with additional information that can be used to determine the location of an outlet when it opens, thus helping the processor identify the specific outlet from which a water demand occurs. While FIG. 3 shows only one such switch 362, each room with one or more hot water outlets may have one or more such switches, and for each switch, processor 311 is preferably provided with activity / status information. For example, a bathroom may have one or more lights above the bathroom, other lights in the shower enclosure, and other lights on the over-sink mirror, each controlled by a different switch. Switch status information from such fixtures can assist the processor in determining which of the various outlets an outlet opens to, and of course, in distinguishing between similar outlets in different rooms. In addition to switches, other presence detectors such as movement or proximity sensors (e.g., PIR sensors, other optical sensors, or capacitive sensors), or door activation sensors (e.g., in facilities where lights are automatically activated) can be used to provide data to the processor to improve the accuracy of the output determination.

[0048] The connections between the processor 311 and the various sensors and actuators may be wired, or wireless using a transceiver 310 (e.g., using allocated frequencies within the ISM radio band), or both, and may use a CAN bus configuration.

[0049] Although shown as a separate item, the valve 309 controlled by the processor to mix cold water with heated water by the appliance 301 can alternatively be integrated internally or externally with the appliance 301 to form a largely independent appliance (although the appliance preferably uses a renewable heat source that is generally a separate entity) and provide temperature-controlled heated water over a wide heat range.

[0050] Having described a hot water supply facility according to one aspect of the present invention, a method for controlling the hot water supply facility, and in particular a method for controlling the supply of heated water, will now be described. This basically involves detecting a demand for water from a first water outlet 302 by the facility's processor 311, identifying that demand as potentially associated with the first water outlet 302, and setting a target water temperature to a first target water temperature associated with the first outlet 302. This may include the processor 311 adjusting the setting of a valve 309 and / or adjusting the setting of a heating appliance to change its output temperature. The method then includes detecting a demand for water from a second water outlet 303, identifying that demand as potentially associated with the second water outlet 303, and setting the target water temperature to a second target water temperature that is higher or lower than the first target water temperature associated with the second outlet 303. Again, this may include processor 311 adjusting the setting of valve 309 and / or adjusting the setting of the heating appliance to change its output temperature so that water at the second target water temperature is dispensed from valve 309. It will be appreciated that the point in the hot water supply system at which the target supply temperature is set may be selected for convenience and efficiency, and appropriate temperature sensors may be installed at relevant locations. In the installation shown in Figure 3, temperature sensor 315 located downstream of valve 309 is a convenient location for setting the target supply temperature because it allows the processor to quickly feedback the results of changes made to the setting of valve 309.

[0051] If the system is configured so that flow rate is regulated for one or more outlets, the method may also include controlling the flow rate, for example by a flow regulator, in accordance with settings stored for outlets identified as outlets to which water demand may be relevant.

[0052] Referring now to FIG. 4, an exemplary configuration of a heating appliance suitable for use with embodiments of the present invention such as those illustrated in FIGS. 1 and 3 will be described.

[0053] Figure 4 corresponds closely to Figure 3, the main difference being the installation of an instant water heater. Identical reference numerals refer to identical parts unless differences are noted. Figure 4 schematically illustrates a facility 400 according to a first aspect of the present disclosure. The facility 400 includes an instant water heater 301 and at least one controllable water outlet 302 located away from the appliance 301, e.g., in a room 350 other than the room in which the instant water heater 301 is located.

[0054] Instant water heating appliance 301 includes an energy storage unit 304, which preferably includes a phase change material for storing energy as latent heat, and a renewable heat source 305, which may be a heat pump, such as an air or ground source heat pump, but may alternatively be a solar heating plant. Energy storage unit 304 typically includes a heat exchanger coupled to the renewable heat source so that energy from renewable heat source 305 can be transferred to a material in energy storage unit 304. Thus, a heat transfer fluid may be heated by renewable heat source 305, circulated through a heat exchanger circuit in energy storage unit 304, and returned to renewable heat source 305 for reheating. Appliance 301 also includes an instant water heater 306.

[0055] A water supply 307, which may be the primary cold water supply, is coupled to energy storage 304, which passes through another circuit of a heat exchanger to extract energy from the energy storage material. Also shown, water supply 307 is preferably coupled to instantaneous water heater 306, which allows hot water to be produced without having to pass through energy storage 304. Heated water emerging from the energy storage passes at 308 to instantaneous water heater 306 and then through thermostatic mixing valve 309 toward the hot water supply, exemplified by piping 310 and controllable outlet 302. (In practice, there will typically be multiple controllable water outlets, including a bath faucet, shower faucet, hand basin faucet, and kitchen faucet, which are omitted for ease of illustration.) Mixing valve 309 also receives a supply of cold water from supply 307, but is coupled to and electronically controlled by a controller or processor 311 of instantaneous water heater 301.

[0056] The diagram shows the water supply from supply 307 to renewable heat source 305 and from the renewable heat source to instantaneous water heater 106 in dashed lines, but this provision is optional. In general, if heat source 305 is a heat pump, the energy from the heat pump may only be supplied to energy storage 304, and there is no hot water supply from energy source 305 directly to instantaneous water heater 306.

[0057] The processor 311 is also coupled to a first temperature sensor 312 in the flow path from the water heater 306 to the mixing valve 309, another 313 at the outlet of the mixing valve 309, and another 315 that senses the temperature of the water from the water supply 307. Also coupled to the processor 311 are a flow or pressure sensor 314 and a flow controller (valve) 316, both of which are in the flow path from the instant water heater 306 to the mixing valve 309. A further flow or pressure sensor 317 coupled to the processor 311 may be provided to supply hot water to the outlet (e.g., a faucet) 302, for example, proximate the outlet 302. Another flow controller (valve) 318 controlled by the processor 311 may also be provided to supply cold water to the energy store.

[0058] Also shown is sensing facility 319 that provides the processor with information regarding the state of the energy storage unit, in particular information that allows the processor to determine the energy storage state of the energy storage unit. Sensing facility 319 may also measure the temperature of the energy storage medium, allowing processor 311 to determine the amount of energy stored as sensible heat. Various suitable sensing facilities are described later in this application. Connections between processor 311 and the various sensors and actuators may be wired, for example, using CAMBUS facilities, wireless, using transceiver 310 (e.g., using allocated frequencies within the ISM radio band), or both.

[0059] The renewable heat source is preferably a heat pump, such as an air-source heat pump, and is therefore generally located largely or entirely outside the building in which the hot water supply system is installed. Typically, the heat pump includes a heat exchanger through which a fluid flows between the heat pump and the appliance 301, heat is captured by the fluid within the heat pump and exchanged with energy storage 304, and the cooled fluid returns to the heat exchanger within the heat pump to extract more energy.

[0060] Although shown as a separate item, valve 309, controlled by a processor to mix cold water with water heated by appliance 301, can alternatively be integrated with appliance 301, either internally or externally, to provide temperature-controlled heated water over a wide heat range (renewable heat source 305, while shown as part of appliance 301, will generally be understood to be a separate entity).

[0061] A hot water supply facility including a PCM energy storage facility (i.e., a PCM energy bank) and a heat pump will now be described. While the foregoing descriptions of methods for configuring a hot water supply system and controlling the temperature of water delivered from the hot water supply facility have been intentionally simplified for ease of application, it should be understood that these methods apply equally to facilities including a PCM energy storage facility and a heat pump.

[0062] One of the many limitations on the applicability of heat pumps is their relatively limited ability to meet demand for hot water compared to their strength as a heat source for space heating, at least when compared to instantaneous gas and electric water heaters such as combi boilers. As noted earlier, for a typical modest-sized dwelling in the UK, heating demand is generally low at 6 kW, while a gas combined boiler can typically provide 20 kW to 30 kW for instantaneous hot water heating even in a modest one- or two-bedroom apartment. While a 6 kW heating demand is easily achievable even with an air-source heat pump in Europe, units capable of delivering 20 to 30 kW are unacceptably large and expensive. Heat pumps suffer a further limitation in their application to domestic hot water supply: the long delay between the heat pump receiving a start signal and the hot water actually being delivered by the heat pump. This delay is typically well over one minute, and can sometimes be as long as two minutes or more. At first glance, this doesn't seem like a big deal, but when you realise that for one of the most common uses of hot water in the home - something like washing your hands - the average time a hot tap runs is between 30 seconds and a minute, it becomes clear that heat pumps have a major obstacle to overcome. Typically, this problem is addressed by storing the hot water in a storage tank and making it available on demand. However, this solution is unattractive for smaller homes which are almost universally installed without an external hot water storage tank, such as the one-, two- and three-storey houses in the UK which currently use gas combined boilers.

[0063] One technology that could improve the applicability of heat pumps to meet demand, especially domestic heat demand, is thermal energy storage, but as distinct from hot water storage.

[0064] One such alternative form of thermal energy storage is the use of phase change materials (PCMs). As the name suggests, phase change materials are materials that exhibit a thermally induced phase change. When a PCM is heated to its phase transition temperature, energy is stored as latent heat rather than sensible heat. Many different PCMs are known, and the choice for any particular application is determined by, among other things, the required operating temperature, cost constraints, and health and safety restrictions (taking into account the PCM's toxicity, reactivity, flammability, stability, etc., and the constraints these impose on the materials needed to contain it). With the appropriate selection of PCMs, thermal energy storage facilities can be designed so that energy from a heat pump is available for instantaneous heating of water for (domestic) hot water systems, thereby helping to address the slow-start problem inherent in heat pump use without the need for bulky hot water tanks.

[0065] This paper presents and describes an energy storage system based on the use of a PCM, particularly suitable for use in facilities that use heat pumps to heat water in hot water supplies. Such an energy storage system includes a heat exchanger with an enclosure, which may contain the following:

[0066] The heat exchanger includes an input circuit for connecting to an energy source such as a heat pump, an output circuit for connecting to an energy sink such as a hot water supply, and a phase-change material for storing energy. The input circuit receives a liquid heated by a heat source (here, a heat pump). If the liquid is hotter than the material in the heat exchanger, energy is transferred from the liquid to the material in the heat exchanger. Similarly, if the liquid is cooler than the material in the heat exchanger, energy from the material in the heat exchanger is transferred to the liquid in the output circuit. Of course, without flow through the output circuit, the amount of energy transferred from the heat exchanger to the outside is limited, and most of the input energy remains within the heat exchanger. In this case, the heat exchanger contains a phase-change material, such as paraffin wax or a salt-hydrate (examples of suitable materials are described below), so that the input energy is mostly transferred to the PCM. By appropriately selecting the phase-change material and the heat pump operating temperature, it is possible to use energy from the heat pump to "charge" an energy "bank" represented by the PCM. Optionally, the energy supply from the heat pump may be supplemented by including one or more electric heating elements in the heat exchanger, which are controlled by the system's processor and are used, for example, when low cost tariffs apply to the electricity supply, or when local or domestic electricity production, such as wind, hydro or solar power, can provide "cheap" energy where there is an expected or anticipated future need for hot water.

[0067] One characteristic of phase change materials that must be accommodated when designing systems that use them is the volume change that occurs during the transition between phases—for example, expansion during a phase change between liquid and solid, and contraction during a phase change between solid and liquid. Typically, the volume change is on the order of 10%. While this volume change is considered a drawback that must be addressed by careful design of the enclosure used to contain the phase change material, the volume change can also be used in a positive way. Including one or more sensors to provide a measurement of pressure within the PCM enclosure can provide data to a processor that enables the processor to determine the state of the phase change material. For example, the processor can determine the energy storage value of the phase change material.

[0068] In addition to, or as an alternative to, measuring the pressure within the enclosure as a means of determining the energy storage capacity of the phase change material, it is possible to use changes in the optical or acoustic properties of the PCM based on the change in phase. Examples of these alternative approaches are discussed below, but first we consider the use of pressure sensing as a means of gathering information about the energy storage state of the PCM.

[0069] FIG. 5 shows a schematic diagram of an energy bank 10 including a heat exchanger, the energy bank including an enclosure 12. Within the enclosure 12 is a heat exchanger input circuit 14 for connection to an energy source (shown here as a heat pump 16) and a heat exchanger output circuit 18 for connection to an energy sink (shown here as a hot water supply system connected to a cold water supply 20 and including one or more outlets 22). Within the enclosure 12 is a phase change material for storing energy. The energy bank 10 also includes one or more condition sensors 24 for providing measurements indicative of the state of the PCM. For example, the one or more condition sensors 24 may be pressure sensors for measuring the pressure within the enclosure. The enclosure also preferably includes one or more temperature sensors 26 for measuring the temperature within the phase change material (PCM). If multiple temperature sensors are provided within the PCM, as is preferred, these temperature sensors are preferably spaced away from the structures of the input and output circuits of the heat exchanger and are suitably spaced within the PCM to obtain a good "picture" of the condition of the PCM.

[0070] The energy bank 10 has an associated system controller 28 that includes a processor 30. The controller may be integrated into the energy bank 10, but is more typically mounted separately. The controller 28 may also include a user interface module 31, either as an integrated unit, a separate unit, or a unit removably mountable to the main body containing the controller 28. The user interface module 31 typically includes a display panel, e.g., in the form of a touch-sensitive display, and a keypad. If the user interface module 31 is separate or separable from the controller 28, it preferably includes wireless communication capabilities that allow the processor 30 and the user interface module of the controller 28 to communicate with each other. The user interface module 31 is used to display system status information, messages, advice, and warnings to the user, as well as to receive user inputs and commands, such as start and stop commands, temperature settings, system overrides, etc.

[0071] The status sensors are coupled to the processor 30, as is the temperature sensor 26, if present. The processor 30 is also coupled to a processor / controller 32 within the heat pump 16 via a wired connection, wirelessly using associated transceivers 34 and 36, or via both wired and wireless connections. In this manner, the system controller 28 can send commands, such as start and stop commands, to the controller 32 of the heat pump 16. Similarly, the processor 30 can also receive information, such as status updates, temperature information, etc., from the controller 32 of the heat pump 16.

[0072] The hot water supply facility also includes one or more flow sensors 38 for measuring flow within the hot water supply system. As shown, such flow sensors may be provided on the system's cold water supply 20 and / or between outputs of the heat exchanger output circuits 18. Optionally, one or more pressure sensors may be included in the hot water supply system, and pressure sensors may be provided upstream of the heat exchanger / energy bank and / or downstream of the heat exchanger / energy bank, for example, alongside one or more of the one or more flow sensors 38. Each flow sensor, temperature sensor, and / or pressure sensor may be coupled to the processor 30 of the system controller 28 via wired and / or wireless connections, for example, using one or more wireless transmitters or transceivers 40. Depending on the nature of the various sensors 24, 26, and 38, they may be interrogable by the processor 30 of the system controller 28.

[0073] An electrically controlled thermostatic mixing valve 160 is preferably coupled between the energy bank outlet and one or more outlets of the hot water supply system and includes a temperature sensor 162 at its outlet. An additional instantaneous water heater 170, for example an electric heater (induction or resistance) controlled by controller 28, is preferably positioned in the water flow path between the energy bank outlet and mixing valve 160. A further temperature sensor may be provided to measure the temperature of the water output by instantaneous water heater 170 and provide that measurement to controller 28. Thermostatic mixing valve 160 is also coupled to a cold water supply 180, controllable by controller 28, to mix hot and cold water to achieve a desired supply temperature.

[0074] Optionally, as shown, the energy bank 10 may include an electric heating element 42 within the enclosure 12 that is controlled by the processor 30 of the system controller 28 and that can be used as an alternative to the heat pump 16 to recharge the energy bank at times.

[0075] FIG. 5 is merely a schematic diagram and shows only the connection of the heat pump to a hot water supply facility. It will be recognized that in many parts of the world, heating is required in addition to hot water. Thus, a heat pump 16 is typically also used to provide heating. Exemplary configurations in which a heat pump provides heating and cooperates with an energy bank for hot water heating are described later in this application. For ease of explanation, the following description of a method of operating an energy bank according to one embodiment of the present invention, as illustrated in FIG. 1 for example, applies equally to energy bank facilities regardless of whether the associated heat pump provides heating.

[0076] A method of controlling a facility according to one aspect of the present invention will now be described with reference to Figure 6. Figure 6 is a simplified flowchart illustrating various actions performed by a processor associated with the facility according to any variant of the third or fourth aspects of the present invention.

[0077] The method begins in step 120 with generating a determination of the amount of energy stored as latent heat in the phase change material based on information from one or more condition sensors 24 .

[0078] The processor then determines, based at least in part on the determination, whether to provide a start signal to the heat pump in step 130. Various factors that the processor can take into account in addition to the state of the PCM are introduced and discussed later in this specification.

[0079] FIG. 7 is another simplified flowchart illustrating various actions performed by a processor associated with the facility in accordance with any variation of the third or fourth aspects of the present invention.

[0080] The method begins at step 300, where a processor receives a signal indicating an open outlet in the hot water supply system. This signal may come from, for example, a flow sensor 38 in the hot water supply system or from a flow sensor 38 in the cold water supply to the hot water system. At step 302, the processor estimates the demand for hot water from the hot water supply system, for example, based on the identity or type of the open outlet or based on the instantaneous flow rate. The processor compares the estimated demand to a first threshold demand level. If the estimated demand exceeds the first threshold demand level, the processor generates a heat pump start message at step 304. If the estimated demand is below the first threshold demand level, the processor compares the estimated demand to a second threshold demand level that is lower than the first threshold demand level. If the estimated demand is below the second threshold demand level, the processor determines not to generate a heat pump start message at step 306.

[0081] If the estimated demand is between the first and second threshold demand levels, the processor takes into account the energy storage level of the energy bank, which may include the processor newly establishing the energy storage level of the energy bank, or the processor may use recently generated information regarding the energy storage level of the energy bank.

[0082] If the determined energy storage level for the energy bank is greater than the first energy storage level threshold, the processor determines not to generate a start heat pump message in step 304. Conversely, if the determined energy storage level for the energy bank is less than the first energy storage level threshold, the processor determines to generate a start heat pump message in step 304.

[0083] Referring now to Figure 8, a method of controlling a facility according to one aspect of the present invention will be described. Figure 8 is a simplified flowchart illustrating various actions performed by a processor associated with an energy bank such as that shown in Figure 5. The method begins at step 200 when processor 30 detects a flow of water in the hot water supply system. The detection is preferably based on data from a flow sensor, such as flow sensor 38 of Figure 5, but may alternatively be based on data from a pressure sensor in the hot water supply system. The associated sensor may be configured to continuously provide measurement data to processor 30, may be configured only to report changes in the measurement data, or the processor may read the associated sensor continuously or periodically (e.g., at least once per second).

[0084] In step 202, processor 30 determines whether the flow rate indicated by the data from the sensor indicates a high or low flow rate, for example, above or below a particular threshold. The processor may use multiple thresholds to classify the flow rate as high, medium, or low, or categories may include very high, high, medium, and low. There may also be categories for very low or non-minimal flow. Processor 30 may also be provided with information (e.g., using techniques such as those described later in this patent application) regarding the flow rate and flow signature (e.g., in the form of a database, model, or MLA) for each outlet 22 or each outlet type in the hot water supply system, and the processor characterizes the detected flow rate as associated with a particular one or type of outlet 22 (e.g., shower outlet, bath outlet, kitchen sink outlet, basin outlet, hand dish outlet).

[0085] If the determination indicates low hot water demand (203), the processor considers the state of the power bank 10 based at least on information from the state sensor 24 in step 204. The processor 30 may at this stage interrogate the state sensor 24 (e.g., a pressure sensor) or check the recently updated energy bank state, and in either case, determine whether the energy bank is in a high energy state 205 (a state in which a large portion of the energy bank's potential latent heat capacity is available) or a low energy state 206 (a state in which a small portion of the energy bank's potential latent heat capacity is available). The processor may also consider information from the temperature sensor 26, for example, the sensible heat energy stored in the energy bank 10. If the processor 30 determines a high energy state, the processor determines not to send a start command to the heat pump, and the process ends in step 207. If the processor 30 determines a low energy state, the processor may determine in 206 to send a start command to the heat pump (step 222).

[0086] If this determination indicates a high demand for hot water (208), the processor may consider the state of the power bank 10 at step 209 based on at least information from the state sensor 24. The processor 30 may at this stage query the state sensor 24 or check the recently updated state of the energy bank, in either case determining whether the energy bank is in a high energy state 210 (where most of the energy bank's potential latent heat capacity is available) or a low energy state 212 (where a small portion of the energy bank's potential latent heat capacity is available).

[0087] The processor may also consider information from the temperature sensor 26, for example, sensible heat energy stored in the energy bank 10. If the processor 30 determines a high energy condition 210, the processor optionally determines a predicted hot water demand in step 214. However, the processor may also be configured to issue a command to start the heat pump in step 222 without predicting the hot water demand (as indicated by the hatched arrow 211) based solely on the magnitude of the flow rate.

[0088] In step 214, processor 30 can predict hot water demand taking into account the determined identity (i.e., the particular outlet) or type of water outlet. For example, if the outlet is identified as a kitchen sink outlet, the faucet will not be run for more than 30 seconds to 1 minute. In contrast, if the outlet is a bath faucet, the faucet will be left open for several minutes, perhaps requiring 120-150 liters of hot water.

[0089] In a first situation, processor 30 determines at 216 not to send a start signal to the heat pump, but instead ends the process, or more preferably, continues to monitor the flow rate to see how long the flow continues at step 218. If the flow stops within the predicted time, the process ends at step 220, but if the water flow continues longer than predicted, processor 30 moves at 219 back to step 209. In a second situation, processor 30 determines at 221 to send a start signal to the heat pump (step 222) (arrow 211 indicates the decision to start the heat pump based solely on instantaneous flow rate or outlet (or outlet type) identification), which is associated with a significant volume of hot water being withdrawn from the hot water supply system.

[0090] After starting the heat pump in step 222 (either from the determination in 206 or 221), processor 30 continues in step 224 to monitor (periodically or continuously) the status of the power bank, and when the status reaches a certain threshold level of charge (225), the processor sends a signal 226 to power down the heat pump (step 226).

[0091] FIG. 9 is another simplified flowchart illustrating various actions performed by a processor associated with an energy bank, such as processor 30 of FIG. 5. Unlike the method described with reference to FIG. 8, the method of FIG. 9 does not rely on detecting a hot water call, i.e., does not rely on opening a hot water system outlet. Generally, FIG. 9 illustrates a method of controlling a facility that includes generating a determination of the amount of energy stored as latent heat in a phase change material and, based on the determination, determining whether to provide a start signal to a heat pump. However, as described below, optional but preferred steps can occur between generating a determination of the amount of energy stored as latent heat in a phase change material and, based on the determination, determining whether to provide a start signal to a heat pump.

[0092] The method begins in step 500 with processor 30 estimating the amount of energy stored in the phase change material of energy bank 10 as latent heat. The amount of heat may be an absolute quantity in kJoules, but may also be a measure of the proportion of potential latent heat capacity currently available. In other words, the processor can effectively determine the proportion of the phase change material that is still in a phase having a higher energy state. Thus, for example, if the phase change material is paraffin wax and involves a phase change from liquid to solid, the liquid phase is a high-energy phase that incorporates a latent heat of fusion, while the solid phase is a low-energy phase, with the latent heat of fusion being lost through solidification.

[0093] If the processor determines (502) that the amount of energy stored as latent heat is sufficient, i.e., exceeds a predetermined threshold, the method proceeds to step 504, where the process stops and the processor awaits the next test (step 500).

[0094] If the processor determines (506) that the amount of energy stored as latent heat is insufficient, i.e., below a certain predetermined threshold, the method proceeds to step 508. In step 508, the processor determines the likelihood of a significant hot water demand within an upcoming period (e.g., within the next 30 minutes, 1 hour, 2 hours, 3 hours, or 4 hours). The period considered is a factor of the thermal capacity of the energy bank, the magnitude of the determined energy shortfall, and the capacity of the heat pump to recharge the energy bank under these circumstances. The demand period considered should be large enough to allow the heat pump to fully recharge the energy bank within that period, so that the energy bank is optimally charged (perhaps fully charged) to be able to handle the predicted or expected demand. Conversely, the heat pump should not be used to recharge the energy bank so far in advance of the expected / projected energy demand that the energy bank loses a significant amount of energy through radiation, conduction, or convection.

[0095] The processor may rely on databases, models, calendars, or schedules, any and all of which may include learned behaviors and behavioral patterns, and scheduled events (such as scheduled absences or other locally scheduled events). The processor may also have access to local weather reports provided (pushed or received), for example, via the Internet or in a wireless transmission and / or in an external thermometer.

[0096] If the processor determines that there is a low probability of significant hot water demand within the time period (510), the method proceeds to step 504 where the process stops and the processor waits for the next test 500.

[0097] If the processor determines (512) that there is a high likelihood of significant hot water demand within the time period, the method proceeds to step 514, where the heat pump is powered on; for example, processor 30 sends a command to heat pump 16, causing processor 32 of heat pump 16 to initiate a heat pump startup procedure, after which the heat pump begins providing heat to the input side of the heat exchanger, thereby putting energy into the phase change material. Next, the processor iteratively determines (516) whether sufficient energy is stored in the energy bank as latent heat in the phase change material. If the processor determines (518) that sufficient energy is stored in the energy bank as latent heat in the phase change material, the method moves to step 520, where the heat pump is powered down, for example, by processor 30 sending an appropriate command. The method continues as long as the processor determines (522) that insufficient energy is stored.

[0098] 5, instead of or in addition to providing one or more condition sensors 24 to measure the pressure within the enclosure, other types of sensors can be provided to measure optical properties of the PCM, such as transparency, absorption, refraction, refractive index, etc., as various of these change with the phase transition of the PCM. Furthermore, various of these properties may exhibit wavelength dependence that changes with the change in phase.

[0099] Thus, the energy bank may further comprise one or more light sources for projecting light onto the phase-change material, and the one or more state sensors 24 may comprise light detection facilities for detecting the light projected from the light sources after the light has passed through the phase-change material. A change between phases in a phase-change material causes a reversible change in the optical properties of the phase-change material, and thus observation of the optical properties of the PCM can be used to gather information about the state of the PCM. Preferably, the optical properties of the PCM are observed in several regions of the PCM, preferably in different directions within the material. For example, light sources and sensors may be positioned such that light from a light source passes lengthwise through the PCM at one or more locations, while other light sources and sensors may be positioned such that light from a light source passes widthwise through the PCM at one or more locations and in one or more directions (width and / or thickness).

[0100] The light source may be controllable to generate light of different colors, and the light sensing facility may be configured to detect at least some of the different colors. By selecting the appropriate color of light based on the particular PCM selected for any application, it is possible to more accurately determine the extent to which the phase of the PCM has changed.

[0101] Preferably, the light source comprises a plurality of separately activatable devices.

[0102] Coupling the light-sensing facility to a processor configured to estimate the amount of energy stored in the phase change material based on information received from the light-sensing facility provides a means of determining the amount of energy stored as latent heat within the PCM, which information can be used in controlling a heat pump. In particular, such information can enable more efficient and appropriate use of the heat pump in charging the PCM energy bank.

[0103] As a further option, the one or more condition sensors 24 for providing measurement data indicative of the amount of energy stored as latent heat within the phase change material can include an acoustic source configured to emit sound into the phase change material and an acoustic sensing facility for detecting the sound emitted from the acoustic source after the sound passes through the phase change material. The change between phases of the phase change material causes a reversible change in the sound absorption properties of the phase change material, and therefore, observation of the acoustic properties of the PCM can be used to gather information regarding the state of the PCM. The acoustic source may be configured to produce ultrasound.

[0104] During the commissioning process described with reference to FIG. 1 , the engineer may also be requested by the processor / system controller 140 to define all hot water outlets (e.g., faucets, showers, bathtubs, kitchens, etc.), or in other words, map the system. In this process, the system controller requests the technician to fully open each outlet (faucet, shower outlet, etc.) in turn, closing each outlet before opening the next, and monitors the resulting water flow with the associated flow measurement device 110. During this process, the associated flow measurement device 110 measures the water flow, and the processor receives these data and adds the results to a database. Based on this information, the system can provide the most efficient flow to each single faucet by controlling the associated flow control device 115 when any outlet is opened.

[0105] A method for mapping a building water supply according to a first aspect of the present disclosure will now be described with reference to FIG.

[0106] The method includes opening a first of a plurality of controllable water outlets, processing signals from at least one flow measurement device 110 with a processor 140 until at least a first flow characteristic is determined, and then closing the first of the plurality of controllable water outlets. The opening of the first of the plurality of controllable water outlets is preferably directed by the processor or system controller 140 and sends a message to a mobile device 150 carried by an associated engineer. For example, a command may be sent via Wi-Fi telling the engineer to open the hot bathtub 136 in the master bathroom 121. The engineer, carrying the mobile device 150, then goes to the master bathroom and fully opens the hot bathtub 136. The mobile device may provide a prompt, preferably an audible sound and a countdown, to the engineer to inform him or her of the exact timing to open the faucet. Alternatively, an application on the mobile device may be configured to accept input from the engineer (e.g., a button press or release) the moment the faucet 136 is opened. In either case, the application can capture the local time of the prompt or moment and then send this local time, along with the identity of the associated controllable outlet, to the system controller 140 or server 145. In this way, delays in the prompt reaching the mobile device 150 or delays in the timing of instructions reaching the controller 140 or server 145 can be taken into account (the mobile device 150 and system controller 140 preferably go through some handshaking procedure before or after the mapping process, so that wither offsets between the clocks of the two devices can be eliminated or even taken into account).

[0107] The engineer can then work his way around the premises by selecting an outlet identifier from a list or menu on the application or by entering an explicit identifier to open each outlet in turn. Alternatively, the system controller may already have a list of all faucets, etc. (generally "controllable outlets") and may prompt the engineer to go to the associated outlet by sending a separate message to the mobile device 150. The application preferably includes an option for the engineer to send a message to the system controller 140 / server 145 so that the engineer is in place and ready to receive instructions to open the next controllable outlet. The process is then repeated for each other hot water outlet until all outlets and their flow characteristics—i.e., delay before flow is detected, rate of rise of flow, maximum flow rate, and any other distinguishing characteristics—have been captured and stored in a database. The processor 140 can then use the characteristics stored in the database to identify a specific one of the multiple controllable water outlets to open based on the similarity of the detected flow characteristics with the respective flow characteristics.

[0108] The processor is also provided with several rules regarding preferred flow rates and optionally flow durations based on the type of outlet (bath faucet, kitchen faucet, basin faucet, cloakroom faucet) and its location (e.g., main bathroom, toilet, children's room, en-suite, cloakroom, kitchen), and uses these rules, together with the outlet identifier recognized from the detected flow characteristics, to establish a target flow rate. The target flow rate is then imposed by the system controller 140 by controlling the associated flow controller 115, and preferably monitored by a corresponding flow measurement device 110. In this manner, the processor 140 can control the supply of water to the identified controllable water outlets by controlling at least one flow regulator based on the identification of the associated outlet.

[0109] Each of the respective flow characteristics may include a respective stable flow rate. The method may then further include configuring processor 140 to control at least one flow regulator 115 to impose a flow rate reduction of at least 10% for each of the plurality of controllable water outlets based on the respective stable flow rates. Optionally, the method may further include configuring processor 140 to control at least one flow regulator 115 to impose a flow rate reduction of at least 10% for any of the plurality of controllable water outlets having a respective stable flow rate greater than 7 liters / minute based on the respective stable flow rates. This is particularly applicable to faucets serving basins in bathrooms, en-suites, and especially cloakrooms, where the faucet is often used primarily to provide water for hand washing and can be effectively achieved with a very modest flow rate.

[0110] The above-described techniques for mapping hot water supply facilities can be used to deploy databases or training logic, such as neural networks or machine learning algorithms (MLAs), which may be used by a processor associated with the energy bank as described above, so that the processor can identify specific outlets or outlet types from detected flow behavior and therefore more easily estimate demand for hot water from the hot water supply, thereby improving the efficiency of heat pump control and energy bank usage.

[0111] Having described the installation and operation of the energy bank and the hot water supply facility, we now consider how the energy bank and heat pump can be integrated into both the hot water supply system and the space heating facility.

[0112] FIG. 10 schematically illustrates a possible arrangement of components of an interface unit 10 according to one embodiment of the present disclosure. The interface unit interfaces between a heat pump (not shown in this figure) and a building hot water system. The interface unit includes a heat exchanger 12 with an enclosure (not separately numbered) containing an input circuit (shown in highly simplified form as 14) for connection to the heat pump and an output circuit (shown in highly simplified form as 16) for connection to the building hot water system (not shown in this figure). The heat exchanger 12 also includes a thermal storage medium for storing energy, which is not shown in the figure. In the embodiment described next with reference to FIG. 10, the thermal storage medium is a phase change material. It will be appreciated that the interface unit corresponds to the energy bank described above. Throughout this specification, including the claims, references to energy bank, thermal storage medium, energy storage medium, and phase change material should be considered interchangeable unless the context clearly requires otherwise.

[0113] Typically, the phase change material in the heat exchanger has an energy storage capacity of 2-5 mJules (in terms of the amount of energy stored by the latent heat of fusion), although more energy storage is possible and useful. Of course, less energy storage is possible, but generally one will want to maximize the energy storage potential of the phase change material of interface unit 10 (subject to practical constraints based on physical size, weight, cost, and safety). Suitable phase change materials and their properties, as well as dimensions, etc., are further described later in this specification.

[0114] Input circuit 14 is in turn connected from node 20 to a pipe or conduit 18 supplied with water from a pipe 22 having a junction 24 connected from the heat pump to a water supply. Node 20 also supplies fluid from the heat pump to a pipe 26, which terminates in a junction 28 intended for connection to the heating network of a house or apartment, for example for piping to an underfloor heating or radiator network, or both. Thus, once interface unit 10 is fully installed and operational, fluid heated by a heat pump (located outside the house or apartment) passes through junction 24 and along pipe 22 to node 20, from where, depending on the setting of three-port valve 32, the fluid flow will either follow pipe 18 to the input circuit 14 of the heat exchanger, or along pipe 26 through junction 28 to the premises' heating infrastructure.

[0115] Heated fluid from the heat pump passes through the heat exchanger input circuit 14 and leaves the heat exchanger 12 along pipe 30. In use, under some circumstances, the heat carried by the heated fluid from the heat pump will give up some of its energy to the phase change material in the heat exchanger and some to the water in the output circuit 16. In other circumstances, as will be described below, the fluid flowing through the heat exchanger input circuit 14 actually gains heat from the phase change material.

[0116] Pipe 30 feeds fluid leaving input circuit 14 to motorized three-port valve 32, which then, depending on the state of the valve, pumps it along pipe 34 to pump 36, which serves to push the flow through connection 38 to the external heat pump.

[0117] The motorized three-port valve 32 also receives fluid from a pipe 40, which receives, via a connection 42, fluid returning from the heating infrastructure of the house or apartment (eg, a radiator).

[0118] Three sets of transducers are provided between the motorized three-port valve 32 and the pump 36: a temperature transducer 44, a flow transducer 46, and a pressure transducer 48. Additionally, a temperature transducer 49 is provided in the pipe 22 which takes fluid from the output of the heat pump. These transducers, like all other transducers in the interface unit 10, are operably connected to or addressable by a processor, not shown, which is typically provided as part of the interface unit but which may be provided as a separate module.

[0119] Although not shown in Figure 10, an additional electric heating element may be provided in the flow path between coupler 24, which receives fluid from the output of the heat pump. This additional electric heating element may be an induction or resistance heating element and is provided not only as a means of compensating for potential failures of the heat pump, but also for possible use in adding energy to the thermal storage unit (e.g., based on current energy costs and projected energy for heating and / or hot water). The additional electric heating element may, of course, also be controllable by the system's processor.

[0120] Also coupled to pipe 34 is an expansion vessel 50 having a valve 52 connected thereto, which allows the charging loop to be connected to the fluid in the heating circuit. Also shown as part of the heating circuit of the interface unit are a pressure relief valve 54, intermediate node 20 and input circuit 14, and optionally a strainer 56 (to capture particulate contaminants), intermediate junction 42, and three-port valve 32.

[0121] The heat exchanger 12 also includes several transducers, including at least one temperature transducer 58, but preferably more (e.g., up to four or more) as shown, as well as a pressure transducer 60. In the illustrated embodiment, the heat exchanger includes four temperature transducers uniformly distributed within the phase change material so that temperature changes can be determined (and thus knowledge of the state of the phase change material throughout its bulk can be gained). Such an arrangement is particularly useful during the design / implementation phase, including optimizing additional heat transfer arrangements, as a means of optimizing the heat exchanger design. However, such a configuration remains beneficial in deployed systems, as having multiple sensors can provide useful information for the processor and machine learning algorithms used by the processor (either simply the interface unit and / or the processor of a system that includes the interface unit).

[0122] The cold and hot water supply circuits of the interface unit 10 will now be described. A connection 62 is provided for connecting the cold water supply from the water main. Typically, before the water from the water main reaches the interface unit 10, it passes through an anti-siphon check valve to reduce its pressure. From the connection 62, the cold water flows along a pipe to the output circuit 16 of the heat exchanger 12. Given the provision of a processor monitoring multiple sensors within the interface unit, the same processor can optionally be given another task: monitoring the pressure at which the cold water is delivered from the main water supply. For this purpose, additional pressure sensors can be installed in the cold water supply line upstream of the connection 62, particularly upstream of any pressure reduction facilities on the premises. The processor can then continuously or periodically monitor the delivered water pressure and even prompt the owner / user to seek compensation from the water supply company if the water main delivers water at a pressure below the legal minimum.

[0123] From the output circuit 16, water heated by passing through the heat exchanger is sent along a pipe 66 to an electric heating unit 68. The electric heating unit 68, under the control of the processor mentioned above, comprises a resistance or induction heating facility, the heat output of which can be modulated according to instructions from the processor.

[0124] The processor is configured to control the electric heater based on information about the state of the phase change material and the heat pump.

[0125] Typically, the electric heating unit 68 has a power rating of 10 kW or less, although in some circumstances a more powerful heater may be provided, for example 12 kW.

[0126] From the electric heater 68, hot water passes along a pipe 70 to a junction 74 to which is connected a hot water circuit including controllable outlets such as taps and showers in a home or apartment.

[0127] A temperature transducer 76 is provided after the electric heater 68, for example at the outlet of the electric heater 68, to provide information regarding the water temperature at the outlet of the hot water system. A pressure relief valve 77 is also provided in the hot water supply and is shown as being located between the electric heater 68 and the outlet temperature transducer 76, although, as is indeed the case with many of the components shown in Figure 10, its exact location is not important.

[0128] Also somewhere in the hot water supply line is a pressure transducer 79 and / or a flow transducer 81, either of which the processor can use to detect a hot water call, i.e., to detect the opening of a controllable outlet such as a tap or shower. The flow transducer is preferably one with no moving parts, based for example on sonic flow detection or magnetic flow detection. The processor can then use the information from one or both of these transducers, along with its stored logic, to determine whether to signal the heat pump to start.

[0129] It will be appreciated that the processor can call on the heat pump to start based on space heating demand (e.g., based on a program stored in either the processor or an external controller) and / or based on signals from one or more thermostats (e.g., room statistics, exterior statistics, underfloor heating statistics), or based on hot water demand. Control of the heat pump may be in the form of simple on / off commands, but may also be in the form of modulation (e.g., using ModBus).

[0130] As in the case of the heating circuit of the interface unit, a triplet of transducers is provided along the cold water supply pipe 64, namely a temperature transducer 78, a flow transducer 80 and a pressure transducer 82. Another temperature transducer 84 is also provided in the pipe 66 intermediate the outlet of the output circuit 16 of the heat exchanger 12 and the electric heater 68. All of these transducers are operatively connected to or addressable by the aforementioned processor.

[0131] Also shown on the chilled water supply line 64 are a magnetic or electric water regulator 86, an electrically operated and modulatable valve 88 (which, like all electrically operated valves, may be controlled by the processor described above), a check valve 90, and an expansion vessel 92. The modulatable valve 88 can be controlled to regulate the flow of chilled water to maintain a desired temperature of the hot water (e.g., as measured by the temperature transducer 76).

[0132] Valves 94 and 96 are also provided for connection to external storage tanks for storing chilled and heated water, respectively. Finally, a double check valve 98 connects the cold water supply pipe 64 to another valve 100 which can be used in conjunction with a fill loop connected to the previously mentioned valve 52 to charge the heating circuit with more water or a mixture of water and corrosion inhibitor.

[0133] Note that while FIG. 10 shows various pipes intersecting, unless these intersections are shown as nodes such as node 20, two pipes shown intersecting do not communicate with each other.

[0134] 10, the heat exchanger 12 may include one or more additional electric heating elements configured to transfer heat to the thermal storage medium. While this may seem counterintuitive, as explained below, it allows for the use of electrical energy to pre-charge the thermal storage medium when it makes economic sense.

[0135] It has been a long-standing practice for energy suppliers to charge rates where the cost per unit of electricity varies by time of day, taking into account fluctuations in demand, and shaping customer behavior to better balance demand and supply capacity. Historically, tariff plans have been fairly coarse-grained, reflecting the technology of both generation and consumption. However, the increasing introduction of renewable sources of electricity, such as solar power (e.g., from solar panels, farms, etc.) and wind power, into countries' power generation fabrics has spurred the development of more dynamic pricing of energy. This approach reflects the variability inherent in such weather-dependent generation. While initially, such dynamic pricing was largely limited to large users, dynamic pricing is increasingly being offered to domestic consumers.

[0136] The degree of pricing dynamism varies from country to country and even between different producers within a given country. At one extreme, "dynamic" pricing may amount to little more than offering different tariffs for different times of the day; such tariffs may apply to static weeks, months, or seasons. However, some dynamic pricing schemes allow suppliers to change prices with less than a day's notice, for example, offering customers 30-minute pricing for today and tomorrow. Some countries offer time frames as short as six minutes, and perhaps including "intelligence" in energy-consuming devices could further shorten the lead time for notifying consumers of upcoming tariffs.

[0137] Using short- and medium-term weather forecasts, it is possible to predict both the amount of energy that may be produced by solar and wind power installations and the likely magnitude of electricity demand for heating and cooling, making it possible to predict extreme periods of demand. Some power generation companies with significant renewable generating capacity have even been known to offer negative charges for electricity - literally paying customers for using excess power. More often, power is offered at a small percentage of the normal rate.

[0138] Incorporating an electric heater into an energy storage unit, such as a heat exchanger in a system according to the present disclosure, allows consumers to take advantage of periods of low-cost supply and reduce their reliance on electricity when energy prices are high. This not only benefits the individual consumer, but is also beneficial more generally, as it reduces demand when fossil fuels must be burned to meet them.

[0139] The processor in the interface unit has a wired or wireless connection (or both) to a data network, such as the Internet, allowing the processor to receive dynamic pricing information from energy suppliers. The processor also preferably has a data link connection (e.g., ModBus) to the heat pump to send commands to the heat pump and receive information (e.g., status and temperature information) from the heat pump. The processor has logic that enables it to learn the household's behavior, and with this dynamic pricing information, the processor can determine whether and when to use cheap electricity to pre-charge the heating system. This can be done by using electrical elements inside the heat exchanger to heat the energy storage medium, but alternatively, it can be done by driving the heat pump to a higher temperature than usual, e.g., 60°C instead of 40-48°C. Heat pump efficiency decreases when operating at higher temperatures, which can be taken into account when the processor determines the optimal time and method to use cheap electricity.

[0140] The system processor may be connectable to a data network such as the Internet and / or a provider's intranet, allowing the local system processor to benefit from external computing power. Thus, for example, a manufacturer of an interface unit may have a cloud presence (or intranet) where computing power is provided for the calculation of false positive and / or false negative identifications, such as forecasted occupancy, activity, tariffs (short-term / long-term), weather forecasts (which may be preferable to publicly available weather forecasts because they can be easily preprocessed for use by the local processor and also because they can be very specifically tailored to the conditions, location, and exposure of the property where the interface unit is installed), etc.

[0141] To protect users from the risk of being burned by superheated water from the hot water supply system, it is advisable to provide a scald protection feature. This can take the form of providing an electrically controllable (modulatable) valve for mixing with the hot water as it leaves the heat exchanger output circuit (the additional valve can be fitted between the nodes of the existing valves 94 and 96 mentioned above).

[0142] 10 shows diagrammatically what may be considered the "working parts" of the interface unit, but does not show the enclosure for these "working parts." An important use of the interface unit according to the present disclosure is as a means to enable a heat pump to be used as a practical contributor to the heating and hot water needs of a dwelling that previously contained a gas-fired combined boiler (or in which such a boiler might otherwise have been installed), and it will be appreciated that, as with conventional combined boilers, it is often convenient to provide an enclosure for both aesthetic and safety reasons. Furthermore, any such enclosure will preferably be sized to fit within a form factor that allows for direct replacement of the combined boiler, which is typically wall-mounted and often found in kitchens coexisting with kitchen cabinetry. Based on a generally rectangular cubic shape with height, width and depth (of course, curved surfaces may be used on any or all surfaces of the container for aesthetic, ergonomic or safety reasons), suitable sizes can be found in an approximate range (height 650mm to 800mm; width 350mm to 550mm; depth 260mm to 420mm), for example 800mm high, 500mm wide and 400mm deep, although larger and particularly tall units may be provided for use in applications that can accommodate them.

[0143] One notable distinction between interface units disclosed for gas combined boilers is that the latter vessel must generally be made of a non-combustible material such as steel, whereas the presence of a high-temperature combustion chamber generally keeps the internal temperature of the interface unit well below 100°C, typically below 70°C, and often below 60°C. Therefore, it becomes practical to use combustible materials such as wood, bamboo, and even paper in constructing the vessel for the interface unit.

[0144] The lack of combustion also opens up the possibility of installing the interface unit in locations that would not typically be considered suitable for a gas combined boiler. And, of course, unlike a gas combined boiler, the disclosed interface unit does not require a flue for exhaust gases. This makes it possible to configure the interface unit for installation, for example, under a kitchen worktop, and to take advantage of notorious dead spots such as under-counter corners. To achieve this, the interface unit can actually be integrated into a secondary cupboard, preferably through collaboration with the kitchen cabinet manufacturer. However, maximum deployment flexibility is maintained by having the interface unit effectively positioned behind some form of cabinet, with the cabinet configured to allow access to the interface unit. The interface unit is preferably configured to allow the circulation pump 36 to slide out and away from the heat exchanger 12 before it is separated from the input circulation path.

[0145] You can also consider utilising other space that is often wasted in adapted kitchens, namely the space under the counter cupboards. There is often space over 150mm high, around 600mm deep and 300, 400, 500 or 600mm or more wide (although allowance must be made for the legs supporting the cabinets). Particularly in new premises, or where a combined boiler is being replaced as part of a kitchen refurbishment, it can make sense to use this space to house at least the heat exchanger for the interface unit, or to use more than one heat exchanger unit for a given interface unit.

[0146] Particularly for interface units designed for wall mounting, it is often desirable to design the interface unit as multiple modules, which is potentially beneficial whatever the application of the interface unit. In such designs, it is advantageous to have the heat exchanger as one of the modules, as the presence of the phase change material can result in the heat exchanger alone weighing more than 25 kg. For health and safety reasons, and to facilitate single-person installation, it is desirable to ensure that the interface unit is delivered as a set of modules, each weighing no more than approximately 25 kg.

[0147] Such weight constraints can be addressed by having one of the modules function as a chassis for mounting the interface unit to the structure. For example, if the interface unit is being mounted to a wall in place of an existing gas combined boiler, it would be convenient to first fasten the chassis supporting the other modules to the wall. Preferably, the chassis is designed to work with the locations of the existing fastening points used to support the combined boiler being replaced. This is potentially possible by providing a "universal" chassis with pre-formed fastening holes according to the spacing and location of common gas combined boilers. Alternatively, it would be cost-effective to produce a range of chassis, each with hole locations, sizes, and spacings that match the location, size, and spacing of a specific manufacturer's boiler. Then, simply specify the correct chassis and replace the appropriate manufacturer's boiler. This approach has several advantages. It avoids the need to drill additional holes in the plugs to accommodate the fastening bolts, which not only eliminates the time required for marking, drilling, and cleaning, but also avoids the need to further weaken the structure of the dwelling where the installation is being performed. This can be an important consideration given the low-cost construction techniques and materials often used in "starter homes" and other low-cost dwellings.

[0148] Preferably, the heat exchanger module and the chassis module are configured to mate together, thus avoiding the need for separable fasteners, which also saves installation time.

[0149] Preferably, the add-on module includes a first interconnect, e.g., 62 and 74, for coupling the output circuit 16 of the heat exchanger 12 to the building hot water system. Preferably, the add-on module also includes a second interconnect, e.g., 38 and 24, for coupling the input circuit 14 of the heat exchanger 12 to the heat pump. Preferably, the add-on module also includes a third interconnect, e.g., 42 and 28, for coupling the interface unit to the premises hot water circuit to be used. It will be appreciated that by mounting the heat exchanger to a chassis that is itself directly connected to the wall, rather than first mounting the connections to the chassis, the weight of the heat exchanger is kept closer to the wall, reducing the cantilever loading effect on the wall fixtures that secure the interface unit to the wall.

[0150] phase change materials

[0151] One suitable class of phase change materials is paraffin wax, which has a solid-liquid phase change at temperatures of interest for domestic hot water supplies and for use in conjunction with heat pumps. Of particular interest are paraffin waxes that melt at temperatures in the range 40-60°C, and within this range waxes can be found that melt at different temperatures to suit specific applications. Typical latent heat capacities are around 180kJ / kg to 230kJ / kg, and specific heats are perhaps 2.27 J / g in the liquid phase. -1 K -1 , 2.1 Jg in the solid phase -1 K -1 It can be seen that the latent heat of fusion can be used to store a significant amount of energy. Even more energy can be stored by heating the phase change liquid above its melting point. For example, if electricity costs are relatively low and you can predict that you will soon need hot water (and you know that electricity costs are likely or will be high), it makes sense to run a heat pump at a higher than normal temperature to "superheat" the thermal energy storage.

[0152] The appropriate wax choice is n-tricosane C 23or Paraffin C 20 -C 33 For example, a phase change material with a melting point of approximately 48°C (112°F) could be used. Applying a standard 3°C temperature difference across the heat exchanger (between the liquid supplied by the heat pump and the phase change material in the heat exchanger) would result in a heat pump liquid temperature of approximately 51°C (132°F). Similarly, on the output side, a 3°C temperature drop can be tolerated to reach a water temperature of 45°C (132°F), which is satisfactory for typical domestic hot water, but hot enough for a kitchen faucet and possibly a bit high for a shower / bathroom faucet. However, cold water can obviously be added to the flow to lower the water temperature. Of course, if a household is trained to accept lower hot water temperatures, or if they are acceptable for some other reason, potentially a phase change material with a lower melting point could be considered, but generally, a phase change temperature in the 45-50°C range is likely to be a good choice. Obviously, you'll want to take into account the risk of Legionella from storing water at such temperatures.

[0153] Although heat pumps (e.g., ground-source or air-source heat pumps) have operating temperatures up to 60°C (although operating temperatures up to 72°C are possible by using propane as a refrigerant), their efficiency tends to be much higher when operating at temperatures in the 45-50°C range. Thus, our 51°C from 48°C phase transition temperature is likely to be satisfactory.

[0154] The temperature performance of the heat pump must also be considered. Generally, the maximum T (the difference between the input and output temperatures of the fluid being heated by the heat pump) is preferably kept in the range of 5-7°C, but can be as high as 10°C.

[0155] Paraffin wax is a preferred material for use as an energy storage medium, but it is not the only suitable material. Salt hydrates are also suitable for latent heat storage systems. Salt hydrates in this context are mixtures of inorganic salts and water, and the phase change involves the loss of all or most of their water. During the phase transition, the hydrate crystals separate into anhydrous (or less aqueous) salt and water. The advantage of salt hydrates is that they have a much higher thermal conductivity (2-5 times) than paraffin wax and a much smaller volume change associated with the phase transition. A suitable salt hydrate for this application is NaSO.5H2O, which has a melting point of approximately 48-49°C and a latent heat of 200 / 220 kJ / kg.

[0156] For purely energy storage purposes, consideration is given to using PCMs with phase transition temperatures significantly above the 40-50°C range. For example, paraffin waxes are available with a wide range of melting points: n-Henicosane C, which has a melting point of approximately 40°C 24 ; n-Docosane C, which has a melting point of approximately 44.5°C 21 ; n-Tetracosane C, which has a melting point of approximately 52°C 23 ; n-Pentacosane C, which has a melting point of approximately 54°C 25 ; n-Hexacosane C, which has a melting point of approximately 56.5°C 26 ; n-Heptacosane C, which has a melting point of approximately 59°C 27 ; n-Octacosane C, which has a melting point of approximately 64.5°C 28 ; n-Nonacosane C, which has a melting point of approximately 65°C 29 ; n-(triacosane) Triacosane C, which has a melting point of approximately 66°C 30 ; n-Hentriacosane C, which has a melting point of approximately 67°C 31 ; n-Dotriacosane C, which has a melting point of approximately 69°C 32 ; n-Triatriacosane C, which has a melting point of approximately 71°C 33 ; Paraffin C with a melting point of 58-60°C 22 -C 45 ; Paraffin C, with a melting point of 66-68°C 21 -C 50 ; RT70HC has a melting point of approximately 6971°C.

[0157] Alternatively, a salt hydrate such as CH3COONa.3H2O-, which has a melting point of about 58°C and a latent heat of 226 / 265 kJ / kg, may be used.

[0158] So far, thermal energy storage has been primarily described as having a single mass of phase change material within a heat exchanger having input and output circuits, each in the form of one or more coils or loops. However, it may be beneficial in terms of heat transfer rate to encapsulate the phase change material within a number of sealed bodies, such as metal (e.g., copper or copper alloy) cylinders (or other elongated forms), surrounded by a heat transfer liquid from which the output circuit (preferably used to provide hot water to a domestic hot water system) extracts heat.

[0159] In such a configuration, the heat transfer liquid may be enclosed within the heat exchanger, or more preferably, the heat transfer liquid may flow through the energy storage unit and transfer heat from a green energy source (e.g., a heat pump) without the use of an input heat transfer coil in the energy storage unit. In this manner, the input circuit may simply be provided by one (or more generally, multiple) inlets and one or more outlets, so that the heat transfer liquid passes freely through the heat exchanger without being confined by a coil or other conventional conduit; the heat transfer liquid transfers heat to or from the enclosed PCM and then to the output circuit (and thus to water in the discharge circuit). In this manner, the input circuit is defined by the one or more inlets and one or more outlets for the heat transfer liquid and a free-form path through the enclosed PCM and through the energy storage unit.

[0160] Preferably, the PCM is enclosed within one or more spaced apart elongated closed-ended pipes (e.g., staggered rows of pipes, each row comprising a plurality of spaced apart pipes), and the heat transfer fluid is preferably arranged to flow transversely over the pipes (or transversely to the length of the pipes or other enclosed enclosure) on a path from the inlet to the outlet, or as directed by one or more impellers provided within the thermal energy storage unit if an input coil is used.

[0161] Optionally, the output circuit may be configured to be located on top of the energy store and positioned above the enclosed PCM, which may be horizontally positioned and arranged above the input loop or coil (so that convection supports upward energy transfer through the energy store), or with the inlet direction of the heat transfer liquid relative to the enclosed PCM, optionally positioned toward the output circuit above. If one or more impellers are used, preferably each impeller is magnetically coupled to an externally mounted motor, or both, so as not to compromise the integrity of the energy store enclosure.

[0162] Optionally, the PCM can be enclosed within an elongated tube, typically of circular cross section, having a nominal outer diameter in the range of 20 to 67 mm, e.g., 22 mm, 28 mm, 35 mm, 42 mm, 54 mm, or 67 mm, and typically these tubes are formed of copper suitable for plumbing. Preferably, the pipe has an outer diameter of 22 mm to 54 mm, e.g., 28 mm to 42 mm.

[0163] The heat transfer fluid is preferably a water-based liquid such as water or water mixed with one or more of a flow additive, corrosion inhibitor, antifreeze, biocide, and may include, for example, an inhibitor of the type designed for use in central heating systems such as Sentinel X100 or Fernox F1 (both RTM) appropriately diluted with water.

[0164] Thus, throughout the specification and claims of this application, the expression input circuit should be interpreted, unless the context clearly requires otherwise, to include installations in which the path of liquid flow from the input of the input circuit to its output is not defined by a regular conduit, but rather involves liquid flowing substantially freely within the enclosure of the energy store, as described above.

[0165] The PCM may be enclosed within a plurality of elongated cylinders having circular or nearly circular cross-sections, preferably spaced apart in one or more rows. Preferably, the cylinders in adjacent rows are offset from one another to facilitate heat transfer from the heat transfer liquid. Optionally, one or more input ports, which may be in the form of multiple input nozzles, provide input facilities for introducing heat transfer liquid into the space around the enclosure and directing the input heat transfer liquid toward and over the enclosure, which is fed by an input manifold. The nozzle bores at their outputs may be generally circular in cross-section or may be elongated to generate jets or streams of liquid that more effectively transfer heat to the enclosed PCM. The manifold may be fed from a single end or from opposing ends to increase flow rate and reduce pressure loss.

[0166] The heat transfer liquid can be pumped to the energy store 12 as a result of the action of a pump in the green energy source (e.g., a heat pump or solar hot water system) or another system pump, or the thermal energy store can include its own pump. After leaving the energy store at one or more outlets in the input circuit, the heat transfer liquid can return directly to the energy source (e.g., a heat pump) or may be switchable using one or more valves to first travel to a heating facility (e.g., underfloor heating, radiators, or other forms of heating) and then return to the green energy source.

[0167] The enclosure may be arranged horizontally with the coils of the output circuit positioned above and over the enclosure. It will be understood that this is only one of many possible arrangements and orientations. A similar configuration may be arranged equally well for a vertically arranged enclosure.

[0168] Alternatively, an energy store using a PCM encapsulation can again use a cylindrical, elongated enclosure like that described above, but in this case using an input circuit in the form of a conduit, such as a coil. The enclosures may be arranged with their long axes aligned vertically, with the input coil 14 and output coil 18 aligned on either side of the energy store 12. However, this arrangement can also be used with other orientations, such as an input circuit at the bottom and an output circuit at the top, and an enclosure with a long axis aligned horizontally. Preferably, one or more impellers are disposed within the energy store 12 to propel the energy transfer liquid from around the input coil 14 toward the enclosure. The or each impeller is preferably coupled to an externally mounted drive unit (e.g., an electric motor) via a magnetic drive system, so that the enclosure of the energy store 12 does not need to be drilled to accept a drive shaft, thereby reducing the risk of leakage if such a shaft were to enter the enclosure.

[0169] The fact that the PCM is encapsulated makes it easy to construct energy storage units that use more than one phase change material for energy storage, and in particular, PCMs with different transition (e.g., melting) temperatures can be combined, thereby creating an energy storage unit that can extend the operating temperature of the energy storage unit.

[0170] It will be appreciated that in embodiments of the type described above, energy storage portion 12 includes one or more phase change materials for storing energy as latent heat in combination with a heat transfer liquid (e.g., water or a water / inhibitor solution).

[0171] A plurality of elastomers configured to decrease in volume in response to an increase in pressure caused by a phase change of the phase change material and to expand again in response to a decrease in pressure caused by a reverse phase change of the phase change material preferably comprise the phase change material within the encapsulation (these may also be used in energy banks using "bulk" PCMs, as described elsewhere herein).

[0172] According to yet another aspect, the present disclosure provides a method of configuring a hot water supply facility having a plurality of controllable hot water outlets, the facility including: a hot water source having an outlet with a controllable outlet temperature; a flow measurement device and at least one flow regulator in a hot water flow path between the outlet of the hot water source and the plurality of controllable hot water outlets; a first temperature sensor for detecting the outlet temperature; and a processor operably connected to the flow measurement device, the first temperature sensor, and the at least one flow regulator, the method including the steps of: installing an outlet temperature sensor in an outlet path of the first controllable hot water outlet; generating data by monitoring variations in temperature of water from the first controllable hot water outlet over time with an outlet temperature sensor; providing the data to a processor; and processing, using the processor, timing information regarding opening times of the first controllable hot water outlet, the data, and information from the first temperature sensor to determine first parameters for controlling outlet temperature of the hot water source, and optionally controlling at least one flow regulator, for use when the processor subsequently detects operation of the first controllable hot water outlet.

[0173] The method further includes generating corresponding data for a plurality of controllable second hot water outlets by installing outlet temperature sensors in the outlet paths of the controllable second hot water outlets; opening the second controllable hot water outlets so that water from the second controllable hot water outlets falls onto the outlet temperature sensors; generating second data by monitoring variations in temperature of the water from the second outlets of the controllable hot water outlets over time using the outlet temperature sensors; providing the second data to a processor; and processing, using the processor, timing information regarding opening times of the second controllable hot water outlets, the second data, and information from the first temperature sensor, so that the processor subsequently determines a second parameter for controlling the outlet temperature of the hot water source for use when it detects operation of the second controllable hot water outlet.

[0174] The present application includes many self-evidently interrelated aspects and embodiments, generally based on a common set of problems, even when many aspects have broader applicability. In particular, the logic and control methods are not necessarily limited to operating with the disclosed hardware and may be applied more broadly, but all are particularly suited to working with hardware and preferred variations thereof in various hardware aspects. Those skilled in the art will understand that certain aspects relate to specific examples of other features, and that preferred features described or claimed in a particular aspect may be applicable to others. While the disclosure would become unmanageably long if explicit references to interoperability were made in every respect, those skilled in the art are expected to understand, and are hereby expressly directed to understand, that preferred features of any aspect may be applied to any other, unless expressly stated otherwise or clearly inappropriate from the context. To avoid repetition, many aspects and concepts may be described only in method or hardware form, but the corresponding apparatus or computer program or logic, in the case of an apparatus discussion, should be interpreted as disclosed in the case of a method or in the case of a method for operating the hardware. Examples of what is meant by the above include the combination of a fluid-based (typically air-sourced) heat pump with a phase-change material, as well as many features of both hardware and software associated with an electric auxiliary heating element and processor control (either in-unit or remotely, or both). While this is a preferred application, most of the methods and hardware are more generally applicable to other heat pumps (thermoelectric and ground sources) and other renewable energy sources (e.g., pumps for solar arrays), as well as alternative auxiliary heating (including less preferred installations of fired heaters such as gas boilers, or less efficient high-temperature, low-COP heat pumps) and alternative thermal storage (including multi-temperature thermal storage arrays). Furthermore, aspects that provide specific installations for any of the components, or their interactions, can be freely used with aspects that focus on alternative elements of the system.

Claims

1. 1. A method for controlling the supply of heated water from a source including a heating appliance to a plurality of water outlets remote from said heating appliance, comprising: detecting a demand for water from a first water outlet, identifying a likely demand associated with said first water outlet, and setting a first target water temperature value associated with said first water outlet to a target water temperature for which water is to be delivered; detecting a demand for water from a second water outlet, identifying a likely demand associated with the second water outlet, and resetting the target water temperature at which water is delivered to a second target water temperature value associated with the second water outlet; Including, The method wherein the demand is associated with an outlet based on detected flow characteristics.

2. 10. The method of claim 1, further comprising controlling a mix of heated water from the heating appliance with water of a different temperature to provide a supply of water at the first target water temperature value or the second target water temperature value.

3. The method of claim 1 or 2, further comprising controlling the heating appliance to adjust the temperature at which heated water is supplied from the heating appliance.

4. The method of claim 1 , wherein the flow characteristics include at least one of a maximum flow rate and / or a rate of change of flow to a predetermined flow rate.

5. 5. The method of claim 4, wherein identifying the demand includes obtaining additional information related to the outlet, such as, for example, an electrical or occupancy signal associated with the outlet, and / or a sensor or transducer associated with the location of the outlet.

6. The method of claim 1 or 2, further comprising detecting likely demand associated with multiple outlets and setting the target water temperature to a third target water temperature value.

7. The method of claim 6 , wherein the third target water temperature value is the lowest target water temperature value associated with any identified potential water outlet.

8. The method of claim 6 , wherein the third target water temperature value is an intermediate temperature between the target water temperature values ​​of the identified potential water outlets.

9. the heating appliance is part of a domestic hot water supply system, the heating appliance including: an energy storage facility including a quantity of phase change material for storing energy in the form of latent heat; a heat exchanger coupled between the hot water system and a heat pump; and a system controller; 9. The method of claim 1, wherein the system controller is configured to receive information from a flow measurement device and information regarding the state of the energy storage facility, and the system controller is configured to sense the opening of any of a plurality of controllable hot water outlets and determine whether to provide a start signal to the heat pump based on the sensed hot water flow rate and the state of the energy storage facility.

10. The system controller receiving status information from the heat pump; The method of claim 9 , configured to use heat pump status information in determining whether to provide a start signal to the heat pump.

11. 1. A domestic hot water supply installation having a plurality of controllable hot water outlets, said installation comprising: a hot water source having an outlet with a controllable outlet temperature; a flow measurement device that provides data regarding water flow between the hot water source and the plurality of controllable hot water outlets; a first temperature sensor for detecting the outflow temperature; a memory for storing parameters linking flow data to an outlet identifier and associating each of the plurality of controllable hot water outlets with a respective target temperature; a processor operably connected to the memory, the flow measurement device, and a first temperature sensor; Including, The processor: determining which of the plurality of controllable hot water outlets is opened based on the detected flow characteristics when one of the plurality of controllable hot water outlets is opened, and then controlling the outlet temperature of the hot water source based on the determination and in accordance with parameters stored for the determined one of the controllable hot water outlets; When another one of the plurality of controllable hot water outlets is opened, the hot water supply facility is configured to determine whether another one of the plurality of controllable hot water outlets is opened, and based on the determination, control the outlet temperature of the hot water source in accordance with parameters stored for the determined other one of the controllable hot water outlets.

12. The facility includes an energy storage facility including a quantity of phase change material, a heat exchanger coupled between the hot water system and a heat pump, and a system controller. the processor: receiving information from the flow measurement device and information regarding the state of the energy storage facility; 12. The hot water supply facility of claim 11, configured to sense the opening of any of a plurality of controllable hot water outlets and determine whether to provide a start signal to the heat pump based on the sensed hot water flow rate and the state of an energy storage facility.

13. the processor: receiving status information from the heat pump; 13. The hot water supply installation of claim 12, configured to use heat pump status information when determining whether to provide a start signal to the heat pump.

14. 14. The hot water supply facility of claim 12 or 13, further comprising an instantaneous water heater in the flow path between the energy storage facility and the outlet of the hot water source, the instantaneous water heater being controlled by the processor.

15. 15. The hot water supply facility of claim 14, wherein the processor is configured to operate the instantaneous water heater only if the energy storage facility and the heat pump are unable to provide sufficient hot water.

16. 16. The hot water supply facility of claim 15, wherein the processor is configured to control the instantaneous water heater based on information about the state of the phase change material and the heat pump.

17. 17. The hot water supply facility of any one of claims 14 to 16, wherein the processor comprises logic for managing the use of energy from the instantaneous water heater, the heat pump, and the phase change material to reduce energy consumption.

18. The hot water supply facility of any one of claims 12 to 17, wherein the processor is configured to supply the energy storage facility, in turn, relying on the heat pump, to supply sufficient hot water.

19. 1. A domestic water supply system comprising: an instant water heating appliance; a plurality of controllable water outlets remote from said appliance; a water supply line arranged to supply heated water from said appliance to the plurality of controllable water outlets; at least one sensor for sensing a characteristic or condition of said water supply line; and a processor coupled to the at least one sensor, The processor: using the at least one sensor to monitor the water supply line feeding the controllable water outlet; Detecting a demand for water from a first one of the water outlets; identifying a demand that may be associated with the first water outlet based on the detected flow characteristics and setting a target water temperature at which water will be delivered to a first target water temperature associated with the first water outlet; detecting a demand for water from a second water outlet of the plurality of water outlets; and a domestic water supply facility configured to identify a demand that may be associated with the second water outlet based on the detected flow characteristics and to set a target water temperature relative to the temperature at which water is to be delivered to a second target water temperature associated with the second outlet.

20. 20. The water supply installation according to claim 19, wherein the one or more sensors preferably include a pressure sensor that senses pressure in the water supply line connected to the appliance.

21. 20. The water supply facility of claim 19, wherein the one or more sensors preferably include a flow sensor for measuring flow in the water supply line located between the fixture and the plurality of controllable water outlets.

22. 22. A water supply installation as claimed in any one of claims 19 to 21, wherein the water boiler appliance includes a valve for mixing heated water with supplied cold water, the valve being controlled by a processor.

23. The water supply facility according to any one of claims 19 to 22, wherein the water heating appliance includes an energy storage facility including a phase change material, and the energy storage facility is configured to store energy by utilizing the latent heat of the phase change material.

24. A water supply installation according to any one of claims 19 to 23, wherein the water boiling appliance includes a renewable heat source, preferably a heat pump, coupled to the processor.

25. 17. The water supply facility of claim 16, wherein the renewable heat source is arranged to supply energy to the energy storage facility.

26. 26. The water supply facility of any one of claims 19 to 25, wherein the water heating appliance includes an instantaneous water heater under the control of the processor, the instantaneous water heater being configured to receive energy from a networked energy supply.

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