The disclosed technology relates to a solar water heating system including a tank configured to store heat transfer fluid, a solar collector in fluid communication with the tank, and a pump system in fluid communication with the tank and the solar collector. The pump system can include a first pump, a second pump, and a valve assembly. The valve assembly can direct the heat transfer fluid from an outlet of the first pump to the solar collector when the first pump is operating and can direct the heat transfer fluid from an outlet of the second pump to the solar collector when the second pump is operating. The first pump and the second pump can transfer the heat transfer fluid from the solar collector back to the tank when the first pump and the second pump are not operating.

A method for determining a preferential minimum power set point by a consumer i, said consumer including an electric water heater, the method including determining the state of the consumer i at an instant k; determining a minimum power set point P.sub.c.sup.min(i,k) at the instant k as a function of the state of the consumer i determined during the determining of the state of the consumer i at an instant k; determining a minimum power set point P.sub.c.sup.min(i,k+1:K) at the instants k+1 to K as a function of the predicted state of the consumer i estimated from the state of the consumer i determined during the determining of the state of the consumer i at an instant k; determining a preferential minimum power set point P.sub.c.sup.min_pref(i,k) as a function of the minimum power set point P.sub.c.sup.min(i,k) at the instant k and of the minimum power set point P.sub.c.sup.min(i,k+1:K) at the instants k+1 to K.

Appliances, such as hot water heaters, hot water heater controllers, and methods of operating such hot water heaters, that take into consideration the availability and capacity of alternative energy sources so that additional efficiencies can be realized by sensing the availability of an alternative energy source and adjusting the control algorithms used to control the use of the available electric power is provided.

A control system suitable for use with a bathing unit system having a water receptacle is provided. The control system comprises first and second heating modules and a controller for controlling operation of the first and second heating modules to heat the water of the water receptacle. The controller is also configured for deriving energy consumption information that may be used, amongst other, to convey energy savings and/or cost savings associated with use of the second heating module in comparison to the use of the first heating module. In some implementations, the derived energy consumption information may be instead/also be used as a parameter in the selection of either one or both the first and second heating modules to heat the water of the receptacle.

The present invention relates to a method for controlling a pump for feeding fluid (F) into a heating system (1000). The heating system has a hot fluid tank (HFT) receiving fluid from an associated fluid reservoir line (5) with an incoming fluid mass flow rate (dm.sub.cw/dt). A pump (P) receives fluid from the line, and pumps the received fluid with a mass flow rate (dm.sub.c/dt). A heat exchanging unit (HX) transfers heat (Q) to the fluid (F) from a medium (R). The transferred heat (Q) is maximized by controlling the pump (P1) in response to this information indicative of the transferred heat (Q), the fluid mass flow rate delivered by the pump thereby having a minimum as a function of the incoming fluid mass flow rate (dm.sub.cw/dt) when maximizing the transferred heat. The invention provides significantly improved heat transfer to the fluid and power savings for the pump. The invention also relates to a heating system, e.g. a heat pump system.

A circulation pump assembly (2) includes an electric drive motor (6) and a control device (10) integrated into the circulation pump assembly (2). At least one internal temperature sensor (16) is arranged in the circulation pump assembly (2) and detects the temperature of the medium delivered by the circulation pump assembly (6) and issues a corresponding temperature signal (42) to the control device (10). The control device (10) is configured, on the basis of the temperature signal (42) of the internal temperature sensor (16), to approximately determine the temperature of the liquid in a liquid storage means (26) which is connected to the circulation pump assembly (2) via a heating circuit (28).

There is provided a hot water supply system including: a controllable hot water supply outlet having when fully opened a given flowrate; a thermal energy store, containing an energy storage medium comprising a phase change material to store energy as latent heat, that is configured to receive energy from a source of renewable energy; a renewable energy source; 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 renewable energy source, energy from the thermal energy store, and optionally an auxiliary water heater intermediate the thermal energy store and the hot water supply outlet; wherein the thermal energy store has an energy storage capacity, when fully charged, that is sufficient to provide hot water to the hot water outlet, at the given flowrate, and at the target system supply temperature for a period of at least 8 minutes, and preferably at least 10 minutes; wherein the renewable energy source is also configured to provide building heating under control of the processor; the processor being configured to: monitor actual demand for hot water from the hot water supply system; predict future demand for hot water from the hot water supply system based on the monitored actual demand; pre-charge the thermal energy store so that sufficient energy will be stored in the thermal energy store to satisfy the predicted demand; and to temporarily divert heat from the renewable energy source to charge the phase change material rather than to provide building heating. A corresponding method is also provided.

A hot water supply system 400 comprises a cold water inlet 402 coupled to a valve 404 which determines the degree of flow in a first path 406 and a second path 408. The first path comprises an Energy Storage Arrangement including a heat exchanger 410 which can heat the water from the inlet. The second path includes an electrical heater 422 which can also heat water from the inlet. The two paths each include a respective flow sensor 416, 428 and the paths re-join before providing an outlet 420 from the supply system via a temperature sensor 418. A controller 430 controls the valve 404 and the electrical heater 422 in response to the sensor signals to provide hot water at a desired temperature using a suitable proportion of stored energy and electrical energy. By charging the Energy Storage Arrangement using a heat pump, an economical and responsive hot water supply system is provided.

Provided is an energy bank including a heat exchanger, the energy bank comprising an enclosure, and within the enclosure: an input-side circuit of the heat exchanger for connection to an energy source; an output-side circuit of the heat exchanger for connection to an energy sink; and a phase-change material for the storage of energy; the energy bank including one or more sensors to provide measurement data indicative of the amount of energy stored as latent heat in the phase change material, the energy bank comprising an optical source to launch light into the phase change material, and the one or more sensors includes an optical sensing arrangement to detect light launched from the optical source after the light has passed through the phase change material, wherein the optical source and the optical sensing arrangement is configured to give a graduated measure of a plurality of different energy storage states from empty to full.

Also provided are: an installation including such an energy bank coupled between a heat pump and the hot water system, a processor being configured to make a determination to trigger the starting of the heat pump based on measurement data from the sensors; and a method of controlling a heat pump in such an installation, the method comprising using measurement data from the one or more sensors to trigger the starting of the heat pump.

Provided is a method of signalling a command to a water heating appliance remote from a controllable water outlet fed from the appliance via a water supply installation, the method comprising: monitoring the water supply that feeds the controllable water outlet; detecting a sequence of changes in a property or state of the water supply consequent on operation of the controllable water outlet; correlating the sequence of changes with a stored pattern; detecting a match above a stored threshold; interpreting the match as a command. It is thus possible to manipulate a tap, or other controllable water outlet, to signal to a processor so that the temperature or flow rate of water supplied by the outlet can be increased. Thus a water supply system may have default flow and temperature levels designed for economy and low water usage, but a user can on demand override one or both of these limitations without the necessity of needing to go to the appliance to reset it. The water heating appliance is preferably an instantaneous water heating appliance. Also provided is a water supply installation including a water heating appliance, a controllable water outlet remote from the appliance, a water supply line arranged to feed the controllable water outlet with heated water from the appliance, and at least one sensor to sense a property or state of the water supply line, and a processor coupled to the at least one sensor; the processor being configured to detect a sequence of changes in a property or state of the water supply consequent on operation of the controllable water outlet; correlate the sequence of changes with a stored pattern; detect a match above a stored threshold; interpret the match as a command; and take an action in accordance with the command.