Provided is a method of signalling energy usage to a user of a hot water outlet of a hot water supply system, the hot water supply system including: a thermal energy store that is supplied with energy from a source of renewable energy; a renewable energy source; an auxiliary water heater coupled to a networked energy supply; a flow transducer operable, when a water flow passes through the hot water outlet, to provide flow rate data for the water flow; and a processor coupled to the flow transducer; the hot water supply system being operable, under the control of the processor, to heat water that is to be supplied to the hot water outlet to a target system supply temperature using a selection of one or more of the auxiliary water heater, the renewable energy source, and energy from the thermal energy store.

An installation includes an in-building hot water supply system, a hot water heat pump, an energy storage arrangement containing a mass of phase change material and a heat exchanger coupled between the hot water system and the heat pump, and a processor to provide a signal to the heat pump based on the opening of an outlet of the hot water supply system. The mass of phase change material has enough latent heat capacity to heat to a predetermined temperature a predetermined quantity of water in the interval from the opening of an outlet of the hot water supply system until at least the heat pump begins to heat water in the hot water supply system. Also provided is a method of controlling a heat pump in such an installation.

Provided is a method of controlling a supply of heated water from a source including a heating appliance (301) to a plurality of water outlets (302, 303) remote from the heating appliance, the method comprising: detecting a demand for water from a first water outlet (302), identifying the demand as likely to be associated with the first water outlet (302) and setting to a first target water temperature value, associated with the first outlet, a target water temperature for the temperature at which water is supplied; detecting a demand for water from a second water outlet (303), identifying the demand as likely to be associated with the second water outlet, and resetting to a second target water temperature value, associated with the second outlet, the target water temperature at which water is supplied; wherein the demand is associated with an outlet based on a detected flow characteristic. Also provided is a hot-water supply installation having a plurality of controllable outlets, the installation including: a source of hot-water with an outlet having a controllable outflow temperature; a flow measurement device to provide data on water flow between the source and the plurality of controllable outlets; a temperature sensor to detect the outflow temperature; a memory storing parameters linking flow data to outlet identity, and associating each of the plurality of controllable outlets with a respective target temperature; a processor operatively connected to the memory, the flow measurement device, and the first temperature sensor; the processor being configured: in the event that one of the plurality of controllable outlets is opened, to determine based on a detected flow characteristic which of the plurality of controllable outlets has been opened, and then based on that determination to control the outflow temperature of the source, in accordance with stored parameters for the determined one of the controllable outlets; and in the event that another of the plurality of controllable outlets is opened, to determine which another of the plurality of controllable outlets has been opened, and then based on that determination to control the outflow temperature of the source, in accordance with stored parameters for the determined another of the controllable outlets.

Provided is a heating installation including an energy store including a latent heat energy storage medium, and a heat pump having a defrost cycle, the heating installation including a hot water supply system arranged to supply instantaneous heated water and space heating to a building, and a processor to control the installation. The processor being configured to: control the supply of heat from the heat pump to the latent heat energy storage medium to store heat for heating water and to a heating circuit for providing space heating; and estimate a likelihood of a defrost cycle by the heat pump. In anticipation of an impending defrost cycle, the processor further being configured to control operation of the installation to store additional energy by at least one of: heating the latent heat energy storage medium to a higher level than a level set for anticipated water heating demand alone and/or heating the building and/or circulating heating fluid of the installation to a higher level than a level set for desired building heating; to compensate for an absence of heat from the heat pump during the impending defrost cycle.

A solar photovoltaic (PV) water heating system includes a tank including at least a first heating unit having at least first and second heating elements, at least one of which is switchable; a PV solar collector; an inverter adapted to convert the output from the PV collector to an alternating power supply; a modulator to modulate the alternating power supply from the inverter; a controller adapted to control the modulator and the switching of the or each switchable heating element; wherein the controller is adapted to control the modulator and the switchable heating elements to maximize the energy drawn from the PV collector.

Disclosed is a method of mapping an in-building water supply installation having multiple controllable water outlets, the installation including a supply of water; in a water flow path between the supply of water and the controllable water outlets, a flow measurement device and a flow regulator; a processor being operatively connected to the flow measurement device and the at least one flow regulator. The method comprises opening a first of the water outlets and processing signals from the flow measurement device with the processor at least until a first flow characteristic is determined; closing the first of the water outlets; repeating the opening, processing and closing operations for each of the other water outlets to determine for each controllable water outlet a respective flow characteristic. Subsequently the processor is configured to; identify the opening of a particular one of the plurality of controllable water outlets based on the similarity of a detected flow characteristic to a respective flow characteristic; and control said at least one flow regulator, based on the identification, to control a supply of water to the identified controllable water outlet.

A storage water heater includes at least one heating device, at least one storage tank wherein water is stored and heated, at least one control and management unit capable of checking at least the heating device, at least one inlet duct through which water may be introduced into the tank, at least one outlet duct through which water may be sent/withdrawn from the tank, wherein there are at least two heating devices, of which at least one main heating device and at least one auxiliary heating device are provided, and wherein the water heater includes a circulator dedicated, via at least one hydraulic connection duct, to the recirculation of the storage water stored in the tank, the circulator being capable of recirculating the water of the storage between the lower part and the top part of the tank, by passing through the auxiliary heating device.

A storage water heater includes at least one heating device, at least one storage tank wherein water is stored and heated, at least one control and management unit capable of controlling the at least one heating device, at least one inlet duct through which water may be introduced into the tank, at least one outlet duct through which water may be sent/withdrawn from the tank, at least two heating devices, of which at least one main heating device and at least one second auxiliary heating device adapted to act as a pre-heater, wherein the water heater includes a by-pass duct capable of deviating, entirely or partially, the water flow entering the tank so as to guide and convey it in a zone of the tank placed at a height higher than the outlet section of the inlet duct.

A solar photovoltaic (PV) water heating system includes a tank (1.020) including at least a first heating unit (1.016) having at least first and second heating elements (1.016.1 . . . 1.016.x), at least one of which is switchable (1.014.1A . . . 1.014.1m); a PV solar collector (1.002); an inverter (1.004) adapted to convert the output from the PV collector to an alternating power supply; a modulator (1.060) to modulate the alternating power supply from the inverter; a controller (1.040) adapted to control the modulator and the switching of the or each switchable heating element; wherein the controller is adapted to control the modulator and the switchable heating elements to maximize the energy drawn from the PC collector.

A system of capturing waste heat includes a heat recovery unit (20) having a heat exchanger (35) arranged to transfer heat between a fluid circulating in a refrigerant loop (60) and a fluid circulating in a solar loop (70) and another heat exchanger (39) arranged to transfer heat between the fluid in the solar loop (70) and a fluid circulating in a water loop (50). Controllable first, second, and third three-way valves (V1-V3) provide or prevent, depending on fluid temperatures, an A-B, B-C, and A-C flow path through the valve. The first valve (V1) is arranged in the water loop (50) upstream of the second heat exchanger (39). The second (V2) is arranged in the solar loop (70) upstream of the second heat exchanger (39). The third valve (V3) is arranged in the solar loop (70) between the first and second heat exchangers (35, 39).