Embodiments of the present invention relate to a service supply system which may be used to provide hot water and/or heating. In some embodiments, the service supply system may also be used to provide chilled water. Embodiments also relate to components of such service supply systems and buildings (or parts thereof) including such components.

It is common for a building to have a system for generating and supplying hot water. Depending on the climate in the region in which the building is located, that building may also have a heating system to alter the temperature of the rooms within the building.

In a large building with lots of rooms, it is not uncommon for a centralised system to be provided for delivering at least some of these services (e.g. hot water and/or heating).

Whilst centralised systems can take advantage of larger and more energy efficient equipment, that equipment is typically not operated in an energy efficient manner. Similarly, the design of such systems is often such that an energy efficiency in one part of the system is lost through ineffective operation or design of another part of the system. Poor maintenance of such systems can also lead to inefficient operation of the system as a whole.

For example, to provide hot water on demand to a large number of different apartments in a building, the centralised system must maintain a large volume of hot water even when there is low demand or must have equipment to heat large volumes of water on very short notice. Otherwise, a relatively sudden high demand for hot water would quickly diminish the supply of hot water and leave some users without any hot water (i.e. the water supplied is of too low a temperature because the stored volume of hot water was exhausted and the system is unable to heat water sufficiently quickly to the required temperature to meet the demand for hot water). Similarly, it is common for centralised heating systems to be operated such that they overproduce in order to be able to handle periods of high demand.

In some centralised systems, the user can control the delivery of heating to a part of the building (e.g. an apartment or even a particular room in an apartment). However, this control can be crude and limited. In other centralised systems, the user has little or no direct control and changes to the heating of a building will apply to a large part of the building (and sometimes even the entire building). These issues with centralised systems are even more apparent as the size of the centralised system increases - so, for example, the larger the building, the more inefficient the control of the supply of hot water and/or heating. Of course, some centralised systems operate in relation to more than one building and so this increases the problems still further.

In some large buildings centralised systems are not viable. For example, a large building may include a number of separate apartments, the residents of which each want control over how such services are provided and how such services are billed. Thus, it is also not uncommon for a large building to include a plurality of subsystems for the supply of hot water and for heating. Each such subsystem may operate in relation to just a part of the large building and may be independently controllable by the occupant of that part of the large building - e.g. the resident of a particular apartment.

Such subsystems are generally not required to oversupply significantly in order to meet demand, because demand is limited to that required by the relatively small part of the building covered by the subsystem and the resident can control the operation of the subsystem to account for their individual demands. Of course, however, such subsystems cannot take advantage of the energy efficiencies of larger equipment used in centralised systems.

Thus, centralised systems can offer more efficient equipment but the control of that equipment in order to ensure an adequate supply of hot water and heating can be inefficient. Individual subsystems are less efficient but allow for more efficient control to maintain an adequate supply of hot water and heating. Centralised systems have the advantage of a large part of the equipment being located in one common plant room. This plant room is typically under the control of the management of the building in relation to which the centralised system is installed. Thus, maintenance can be straightforward as there is often only one location for the engineer to access and access is controlled by someone responsible for the building as a whole.

In a distributed subsystem arrangement (see above), equipment is spread between a number of locations and each location may be controlled by a different party (for example, by the resident of a particular apartment). This is a particular issue where a maintenance or safety engineer is tasked with servicing all of the subsystems in a building - as access must be negotiated with each party involved. In both the distributed subsystem arrangement and the centralised system, there are problems associated with large upgrades and/or maintenance and/or commissioning - as access must be gained to each separate part of the building in turn (with a large number of access negotiations being required). As will be appreciated, therefore, there are numerous problems associated with prior systems for the provision of hot water and heating.

Some efforts have been made in the art to overcome the issues created by inefficient control of centralised systems by, for example, using what is viewed as more efficient equipment - often using renewable energy sources. Whilst such equipment is generally not controlled more efficiently in practice, the oversupply issue is less of a problem because that oversupply is more efficiently provided. In many systems, the oversupply issue has been addressed by reducing supply, inevitably leading to undersupply at times of high demand.

These and other issues cause significant problems in relation to the design and operation of service systems for large buildings. Indeed, whilst some of the problems are particularly relevant to apartment buildings, the same problems will equally apply to .

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other large multi-occupancy buildings - such as schools, office buildings, hospitals, shopping malls, and the like.

Issues with access to parts of a large building can be particularly significant in apartment buildings with a large number of social housing apartments, hospitals, and buildings in which access to parts is restricted (e.g. due to security concerns - such as airports, prisons, secure government facilities, and the like).

In centralised systems, plant rooms are generally located in basements and the like. Space within the plant room is limited and in some instances the plant room was never originally intended to house so much equipment and/or modern equipment and/or pre- assembled equipment (the building may be from an era which pre-dates the type of equipment being installed). Therefore, maintenance of equipment within the limited space in some plant rooms can be an issue - due to the general space constraints and difficulties in gaining adequate access to the equipment.

In addition, with a centralised system, it is notoriously difficult to ensure that each part of the building is correctly metered and/or is billed for an appropriate level of service. In some such systems, metering equipment is distributed about the building and access to that metering equipment can be limited or restricted - this can reduce the ability of an operator of the system to determine meter readings and can also prevent the operators from identifying metering equipment which has been tampered with by a user.

Therefore, embodiments of the present invention seek to ameliorate one or more problems associated with the prior art.

Accordingly, an aspect of the present invention provides a service supply system for use in the provision of hot water and/or heating, the system comprising: a first service supply unit configured to heat a liquid; a second service supply unit configured to heat the liquid; and a storage and distribution unit configured to receive the heated liquid from the first and second service supply unit and to deliver the heated liquid to a distribution system, wherein the storage and distribution unit includes a first tank configured to receive heated liquid from the first service supply unit and configured to receive heated liquid from the second service supply unit, and wherein the first tank 5

comprises a stratification vessel including at least one baffle configured to inhibit the movement of liquid within the first tank. The at least one baffle may include a plate with one or more apertures therethrough. The at least one baffle may include a plate with one or more ridges thereon. The first tank may be configured to supply heated liquid from the second service supply unit to the first service supply unit for further heating. The first service supply unit may include at least one condensing boiler configured to heat the liquid and/or an electrically operated heater. The condensing boiler may be a natural gas or oil operated boiler. The second service supply unit may use a renewable energy source to heat the liquid. The second service supply unit may include at least one of a gas absorption heat pump, a biomass generator, a solar panel, a ground source heat pump, a hydraulic power plant, a wind power plant, a district heating system, an air source heat pump, an electrically operated heater, a solar thermal collector, and a photovoltaic panel. The system may further comprise a control system which is configured to control movement of the liquid between the first and second tanks. The control system may be further configured to control the operation of the first and second service supply units. Another aspect provides a heat transfer unit for use in the provision of hot water and/or heating, the heat transfer unit comprising: a first heat exchanger configured to receive heated liquid through a first heat exchanger conduit, the heated liquid being from a distribution system, to use the heated liquid to heat water in a second heat exchanger conduit for providing hot water or heating, and to return the heated liquid to the distribution system; and connectors configured to be coupled to a bypass pipe to provide liquid communication between: first and second ends of the first heat exchanger conduit; OR first and second ends of the second heat exchanger conduit; OR a second end of the heat exchanger conduit and a drain. The heat transfer unit may further comprise the bypass pipe. The bypass pipe may provide a constricted flow path for the heated liquid between the first and second ends of the first heat exchanger conduit, the constricted flow path mimicking the flow of liquid through the heat exchanger. The bypass pipe may provide a constricted flow path for the water between the first and second ends of the second heat exchanger conduit, the constricted flow path mimicking the flow of water through a building unit heating system output, one or more building unit heat members, and a building unit heating system return. The bypass pipe may provide a constricted flow path for the water between the second end of the heat exchanger conduit and the drain, the constricted flow path mimicking the flow of water through building unit hot water supply output and use of the _

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water in a building unit. The bypass pipe may be a flexible pipe. Another aspect provides a service supply system for use in the provision of hot water and/or heating, the system comprising: a first service supply unit configured to heat a liquid; a second service supply unit configured to heat the liquid; a control system; and a storage and distribution unit configured to receive the heated liquid from the first and second service supply unit and to deliver the heated liquid to a distribution system, wherein the control system is configured to control the operation of the first service supply unit and the second service supply unit in accordance with a control strategy, and wherein the control strategy uses information about at least one of the following in order to determine the control strategy: a type and operating characteristics of the first and second service supply units of the system; a type and operating characteristics of the distribution and storage unit; a type and operating characteristics of a distribution pump of the storage and distribution unit; a type and occupancy characteristics of at least one building unit which the system serves; details of a layout of at least one building unit which the system serves; details of a geographical location of at least one building unit which the system serves; information about the climate in the geographical location of at least one building unit which the system serves; details of an orientation of at least one building unit which the system serves; historic information regarding service usage characteristics for at least one building unit; one or more economic constraints; one or more environmental constraints; one or more indicators of a likely atypical demand; and public holidays. The control strategy may be a predictive control strategy. The control system may further comprise an ancillary service interface which is configured to receive information from an ancillary service, wherein the control system may be configured to use the information from the ancillary service to determine the control strategy. The ancillary service may be a weather forecast and the information from the ancillary service may be a weather forecast. The ancillary service may be a news service and the information may be news. Another aspect provides a service supply system for use in the provision of hot water and/or heating, the system comprising: a first service supply unit configured to heat a liquid; a distribution pump operable to pump the heated liquid to one or more heat transfer units; a control system; and a storage and distribution unit configured to receive the heated liquid from the first service supply unit and to deliver the heated liquid to a distribution system, wherein the control system is configured to control the operation of the first service supply unit and/or the distribution pump in accordance with a control strategy, and wherein the control strategy is a predictive control strategy and/or wherein the control strategy seeks to minimise the temperature of liquid returned by the distribution system to the storage and distribution unit. The control system may be configured to determine the control strategy using information about a type and operating characteristics of the first service supply unit of the system. The control system may be configured to determine the control strategy using information about a type and operating characteristics of the distribution and storage unit. The control system may be configured to determine the control strategy using information about a type and operating characteristics of the distribution pump. The control system may be configured to determine the control strategy using information about a type and occupancy characteristics of at least one building unit which the system serves. The control system may be configured to determine the control strategy using information about details of a layout of at least one building unit which the system serves. The control system may be configured to determine the control strategy using information about details of a geographical location of at least one building unit which the system serves. The control system may be configured to determine the control strategy using information about information about the climate in the geographical location of at least one building unit which the system serves. The control system may be configured to determine the control strategy using information about details of an orientation of at least one building unit which the system serves. The control system may be configured to determine the control strategy using information about historic information regarding service usage characteristics for at least one building unit. The control system may be configured to determine the control strategy using information about one or more economic constraints. The control system may be configured to determine the control strategy using information about one or more environmental constraints. The control system may be configured to determine the control strategy using information about public holidays. The control system may be configured to determine the control strategy using one or more indicators of a likely atypical demand. The system may further comprise a second service supply unit configured to heat the liquid, wherein the control system further controls the operation of the first and second service supply units based on the control strategy. The control system may further comprise an ancillary service interface which is configured to receive information from an ancillary service, and to use the received information to determine the control strategy. The ancillary service may be a weather forecast or news service and the ancillary service interface may be configured to receive weather ₀

o

forecast and/or news information. Another aspect provides a modularly constructed plant room for at least part of a service supply system, the modularly constructed plant room comprising: a metal framework; and a plurality of removable panels configured to be secured to the metal framework. The metal framework may be at least partially dismantlable. Another aspect provides a modularly constructed plant room in combination with a service supply system. The service supply system may include at least one service supply unit and at least one storage and distribution unit housed in the modularly constructed plant room. Another aspect provides a heat transfer unit for use in the provision of hot water and/or heating, the heat transfer unit comprising: a first heat exchanger configured to receive heated liquid from a distribution system through a distribution output conduit, to use the heated liquid to heat water for providing hot water or heating, and to return the heated liquid to the distribution system though a distribution return conduit; at least one metering device configured to measure the volume of water heated by the heat transfer unit; at least one temperature sensor configured to measure a temperature associated with the heat transfer unit; and a tamper detection sub-system configured to compare the measured temperature by the at least one temperature sensor to an expected temperature for the volume of water measured by the at least one metering device, wherein the tamper detection sub-system is configured to issue an alert when the measured temperature does not match the expected temperature. The expected temperature may be an expected temperature range. The temperature sensor may be configured to sense a temperature of the returned heated liquid or the heated water. A heat transfer unit may further comprise a shut-off valve which is operable to inhibit or substantially prevent operation of the heat transfer unit when activated, wherein the shut-off valve may be configured to be activated by the alert issued by the tamper detection sub-system. Another aspect provides a control module configured for use with a service supply system for use in the provision of hot water and/or heating, the system comprising: a first service supply unit configured to heat a liquid; a second service supply unit configured to heat the liquid; and a storage and distribution unit configured to receive the heated liquid from the first and second service supply unit and to deliver the heated liquid to a distribution system, wherein the control system is configured to issue instructions to control the operation of the first service supply unit and the second service supply unit in accordance with a control strategy, and wherein the control strategy uses information about at least one of the following in order to determine the control strategy: a type and operating characteristics of the first and second service supply units of the system; a type and operating characteristics of the distribution and storage unit; a type and operating characteristics of a distribution pump of the storage and distribution unit; a type and occupancy characteristics of at least one building unit which the system serves; details of a layout of at least one building unit which the system serves; details of a geographical location of at least one building unit which the system serves; information about the climate in the geographical location of at least one building unit which the system serves; details of an orientation of at least one building unit which the system serves; historic information regarding service usage characteristics for at least one building unit; one or more economic constraints; one or more environmental constraints; one or more indicators of a likely atypical demand; and public holidays. Another aspect provides a control module configured for use with a service supply system for use in the provision of hot water and/or heating, the system comprising: a first service supply unit configured to heat a liquid; a distribution pump operable to pump the heated liquid to one or more heat transfer units; and a storage and distribution unit configured to receive the heated liquid from the first service supply unit and to deliver the heated liquid to a distribution system, wherein the control system is configured to control the operation of the first service supply unit and/or the distribution pump in accordance with a control strategy, and wherein the control strategy is a predictive control strategy. Another aspect provides a building unit in combination with at least one heat transfer unit. Another aspect provides a building including a system as above. Another aspect provides a plant including a control module. Another aspect provides a building including at least one building unit. Another aspect provides a building including a plant. Another aspect provides a group of buildings. Another aspect provides a service supply system for use in the provision of hot water and/or heating, the system comprising: a first service supply unit configured to heat a first portion of a liquid to a first temperature; a second service supply unit configured to heat a second portion of the liquid to a second temperature; and a storage and distribution unit configured to receive the heated first and second portions of the liquid from the first and second service supply units and to deliver the heated first and second portions of the liquid to a distribution system, wherein the first temperature is higher than the second temperature, the storage and distribution unit is configured to provide at least part of the first portion of the liquid to the distribution system for use in heating one or more building units, and to provide at least part of the second portion of the liquid to a building unit hot water heating mechanism for use in the provision of hot water to the building unit. The first and second portions of the liquid may be portions of one circulating liquid. At least a part of the second portion of the liquid may be provided to the first service supply unit for further heating, such that the second service supply unit pre-heats the liquid for the first service supply unit. The storage and distribution unit may include a pre-heated liquid tank which is configured to receive the second portion of the liquid and a high temperature tank which is configured to receive the first portion of the liquid. The pre-heated liquid tank and the high temperature tank may be in liquid communication. The pre-heated liquid tank may be further configured to receive the first portion of the liquid after the first portion of the liquid has been used in the heating of one or more building units. The storage and distribution unit may include a stratification vessel which is configured to receive the first and second portions of the liquid. The first service supply unit may include at least one condensing boiler configured to heat the liquid. The condensing boiler may be a natural gas or oil operated boiler. The second service supply unit may use a renewable energy source to heat the liquid. The second service supply unit may include at least one of a gas absorption heat pump, a biomass generator, a solar panel, a ground source heat pump, a hydraulic power plant, a wind power plant, a district heating system, an air source heat pump, an electrically operated heater, a solar thermal collector, a photovoltaic panel. Another aspect provides a combination of a service supply system and a building unit hot water heating mechanism, wherein: the service supply system is as above; and the building unit hot water mechanism is configured to receive the at least part of the second portion of the liquid for use in the provision of hot water to the building unit. Another aspect provides a building including a system as above. Another aspect provides a building including a combination of a service supply system and a building unit hot water heating mechanism as above. Another aspect provides a group of buildings as above.

Embodiments of the present invention are described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a building in accordance with some embodiments;

Figure 2 shows buildings, building units, and sub-buildings in accordance with some embodiments;

Figure 3 shows building units in accordance with some embodiments; . .

1 1

Figure 4 shows a storage and distribution unit in accordance with some embodiments;

Figure 5 shows a service supply unit according to some embodiments;

Figure 6 shows a service supply unit according to some embodiments;

Figure 7 shows a distribution unit according to some embodiments;

Figure 8 shows a system according to some embodiments;

Figure 9 shows a heat transfer unit according to some embodiments;

Figure 10 shows a control system according to some embodiments;

Figure 1 1 shows a modularly constructed plant room according to some embodiments;

Figure 12 shows a first view of a stratification vessel of some embodiments;

Figure 13 shows a second view of a stratification vessel of some embodiments (the same vessel as is shown in figure 12);

Figure 14 shows a baffle of some embodiments;

Figure 15 shows a distribution unit according to some embodiments;

Figure 16 shows a distribution unit according to some embodiments;

Figure 17 shows a storage and distribution unit in accordance with some embodiments; and

Figure 18 shows a system of some embodiments.

With reference to Figures 1 & 2, embodiments of the present invention are configured for operation in relation to a building 1 . The building 1 could be any number of different types of building 1 - for example, a multi-occupancy building; a building in residential use; a building in retail use; a building in office use; a building in commercial use; a building in storage use; a communal housing building; an apartment block; a hospital; a healthcare centre; an office block; a school; a swimming pool; a sports facility; changing facilities; temporary or mobile installations for events; accommodation facilities; industrial and military sites; different industrial uses such as manufacturing, distribution, food storage, food processing, ripening, agriculture and animal husbandry; a hotel; an airport; a prison; or a mixture of different types (i.e. uses). In some embodiments, the building 1 may in fact comprise a plurality of sub-buildings 1 a - i.e. a plurality of free standing buildings 1 a which may or may not be interconnected by corridors, walkways, skyways, and/or tunnels. . ^

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The building 1 (or sub-buildings 1 a) may comprise a high-rise building, a skyscraper, or any other form or configuration of building. As will be appreciated, the building 1 or sub- building 1 a has a roof, one or more outer walls, and may include grounds around the one or more outer walls and associated with the rest of the building 1 or sub-building 1 a.

The building 1 includes a plurality of building units 2. Each building unit 2 may be, for example, an apartment, an office, a ward, a department, a sector, a zone, or the like. Each building unit 2 may comprise one or more rooms which may be interconnected by doors, windows, and the like. In some embodiments, each sub-building 1 a is a building unit 2. In some embodiments, each sub-building 1 a comprises a plurality of building units 2.

Each building unit 2 may be under the control of a different end-user. A building unit 2 or a group of building units 2 (which may include an entire building 1 or sub-building 1 a) may be under the control of a different management-user. An end-user may, for example, be the resident of an apartment, an occupier of an office, a nurse in a hospital, an occupier of a hotel room, or the like. Each management-user may, for example, be the owner of a building or other group of building units 2, a management business tasked with managing a building or other group of building units 2, a landlord, a facilities manager, a hotel manager, or the like.

There is a desire to provide one or more services to each building unit 2 of the building 1. These services may include one or more of hot water, heating, and communication services. As will be appreciated, therefore, the end-user is the user desiring to make use of the one or more services. The management-user is responsible for managing the one or more building units 2 for which they are responsible - for example, to ensure that maintenance is performed, that services are available to a building unit 2, etc.

An embodiment of the present invention includes a storage and distribution unit 3 (see figure 4) for use in the provision of one or more services for use by one or more building units 2 of a building 1 . The one or more services may include one or more of hot water, heating, and communication services. The storage and distribution unit 3 is configured to be connected to at least one service supply unit 4 and to a distribution system 5. The at least one service supply unit 4 is configured for use in generating the one or more services for storage and distribution by the storage and distribution unit 3. The distribution system 5 is configured to distribute the one or more services from the storage and distribution unit 3 to one or more building units 2.

Operation of one or more of the storage and distribution unit 3, the at least one service supply unit 4, and the distribution system 5, may be controlled by a control system 6.

Collectively, one or more of the storage and distribution unit 3, the at least one service supply unit 4, the distribution system 5, and the control system 6, form a service supply system 100. Embodiments of the storage and distribution unit 3 will now be described.

In some embodiments, the storage and distribution unit 3 is configured to store and distribute heated liquid (e.g. water) for use in the provision of heating and/or hot water services. In this context, heated liquid is a liquid which has been heated to a temperature which is higher than the ambient temperature in the region of the storage and distribution unit 3. In some embodiments, heated liquid is liquid which has been heated to a temperature above 50°C (and possibly below 100°C).

The storage and distribution unit 3 may, therefore, include one or more tanks 31 configured to store heated liquid (e.g. water). In some embodiments, the or each tank 31 comprises a respective stratification vessel 31 a. As such, in some embodiments, one tank 31 is provided and this tank 31 may be a stratification vessel 31 a.

In some embodiments, the or each stratification vessel 31 a acts as a thermal store which is configured to store heated liquid (e.g. water), with hotter liquid towards the top of the stratification vessel 31 a and cooler liquid towards the bottom of the stratification vessel 31 a. One or more baffles 31 1 may be located within the stratification vessel 31 a and configured to inhibit the movement of liquid within the stratification vessel 31 a. The . .

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one or more baffles 31 1 act to enhance the temperature stratification within the stratification vessel 31 a.

Accordingly, the or each stratification vessel 31 a may be a vessel which has a height which is greater than a width of the stratification vessel 31 a. The or each baffle 31 1 may extend across at least a portion of the cross-sectional area of the stratification vessel 31 a. The or each baffle 31 1 may include a plurality of slits or apertures (e.g. piercings) to allow the restricted passage of liquid (e.g. water), therethrough. In some embodiments, the or each baffle may additionally or alternatively include one or more ridges, or another form of uneven surface (e.g. one or more dimples), to alter the flow of liquid (e.g. water) over the baffle within the stratification vessel 31 a. In some embodiments, the or each baffle 31 1 may be oriented perpendicular to a longitudinal axis of the stratification vessel 31 a. In some embodiments, the or each baffle 31 1 may be inclined with respect to the longitudinal axis of the stratification vessel 31 a - for example, the or each baffle 31 1 may form a helix or partial helix within the stratification vessel 31 a.

In some embodiments, the or each baffle 31 1 includes at least one vane. The or each vane may be rotatable about its longitudinal axis to control the flow of liquid over the vane. The or each vane may extend substantially perpendicular to the longitudinal axis of the stratification vessel 31 a. In some embodiments, the orientation of the or each vane is substantially parallel to the longitudinal axis of the stratification vessel 31 a (e.g. to encourage rotational movement of the liquid about the volume defined by the stratification vessel 31 a). In some embodiments, the or each vane is attached to a hub which is configured to rotate such that the or each vane rotates within the stratification vessel 31 a to assist in movement (or to inhibit movement) of the liquid within the stratification vessel 31 a. In some embodiments, the or each vane is configured to assist or restrict movement of the liquid up or down the stratification vessel 31 a - with or against the flow of liquid due to convection within the stratification vessel 31 a.

As will be appreciated, within the or each stratification vessel 31 a, liquid (e.g. water) is not free to rise or fall uninhibited due to convection. Instead, the free movement of liquid within the stratification vessel 31 a is inhibited by the or each baffle 31 a which may .

15

serve to slow or accelerate the flow of some parts of the liquid with respect to other parts.

The or each stratification vessel 31 a (or other form of tank 31 ) may include one or more temperature sensors 312. In embodiments, a plurality of temperature sensors 312 is provided with the temperature sensors 312 spaced apart along a height of the stratification vessel 31 a (or other form of tank 31 ). The or each temperature sensor 312 is configured to measure the temperature of the liquid in the stratification vessel 31 a (or other form of tank 31 ) at a particular height within the stratification vessel 31 a (or other form of tank 31 ). Accordingly, the or each temperature sensor 312 may extend through a wall of the stratification vessel 31 a (or other form of tank 31 ) with an operative end extending into or close to the liquid (or the volume in which the liquid is to be contained). The or each temperature sensor 312 is configured to deliver an electrical output signal representative of a temperature of the liquid adjacent the temperature sensor 312 to control equipment 16 which may be associated with the stratification vessel 31 a (or other form of tank 31 ).

The stratification vessel 31 a (or other form of tank 31 ) may include one or more pressure sensors 315. The or each pressure sensor 315 is configured to measure a fluid pressure (e.g. a liquid pressure) within the stratification vessel 31 a (or other form of tank 31 ). Accordingly, the or each pressure sensor 315 may extend through a wall of the stratification vessel 31 a (or other form of tank 31 ) with an operative end extending into or close to the liquid (or the volume in which the liquid is to be contained). The or each pressure sensor 315 is configured to deliver an electrical output signal representative of a pressure of the fluid (e.g. liquid) within the stratification vessel 31 a (e.g. tank 31 ) to control equipment 16 which may be associated with the stratification vessel 31 a (or other form of tank 31 ).

The or each stratification vessel 31 a (or other form of tank 31 ) may be associated with a respective manifold 313 which is configured to moderate and/or control the flow of liquid into and/or out of the stratification vessel 31 a (or other form of tank 31 ). The manifold 313 may include a plurality of input and/or a plurality of output pipes 314 which are in liquid communication with the associated stratification vessel 31 a (or other form of tank 31 ). The input and/or output pipes 314 may be distributed along a height of the stratification vessel 31 a (or other form of tank 31 ). Each input and/or output pipe 314 may be associated with a respective valve (which may be part of the manifold 313) and which is configured to control and/or moderate the flow of liquid through the associated pipe 314. Each valve may be coupled to the control equipment 16 which may be associated with the stratification vessel 31 a (or other form of tank 31 ).

As will be appreciated, therefore, in some embodiments the manifold 313 may be used to control the flow of liquid into and/or out of the associated stratification vessel 31 a (or other form of tank 31 ) at different heights of the stratification vessel 31 a (or other form of tank 31 ). This flow of liquid (e.g. water) can be used, therefore, to help to control the temperature of the liquid within the stratification vessel 31 a (or other form of tank 31 ) at different heights.

In some embodiments of the storage and distribution unit 3, may include a plurality of stratification vessels 31 a (or other forms of tank 31 ) generally as described above. Each stratification vessel 31 a may have a different or a substantially different arrangement of one or more baffles 31 1 associated therewith.

In some embodiments in which a plurality of stratification vessels 31 a (or other forms of tank 31 ) may be provided, the stratification vessels 31 a (or other form of tank 31 ) are coupled in liquid communication with each other. This coupling may be achieved by interconnecting respective manifolds 313 of the stratification vessels 31 a (or other form of tank 31 ). In some embodiments, there is a single stratification vessel 31 a. In some embodiments, the functions of the first and second tanks 31 of some embodiments have been combined through the use of a single stratification vessel 31 a. This is possible because, in a two tank 31 system, one tank handles liquid (e.g. water) which is hotter than the liquid in the other tank. However, through the use of the stratification vessel 31 a a part (e.g. a higher part) of the stratification vessel 31 a can store the hotter liquid whilst another part (e.g. a lower part) of the stratification vessel 31 a can store the cooler liquid. The use of one or more baffles 31 1 within the stratification vessel 31 a allows both hotter and cooler liquid to be stored in the same vessel or tank without the problems associated with the free moment of liquid of different temperatures within the vessel or tank (e.g. through convection).

The combining of the roles of two tanks 31 reduces losses which are associated with the ends of the tanks 31 . In particular, two tanks will have four ends which are exposed and through which heat is lost. A single tank will only have two ends through which heat may be lost.

As will be appreciated the or each manifold 313 may be configured to supply heated liquid (e.g. water) from one or more associated tanks 31 (which may include one or more stratification vessels 31 a) to a main heating output conduit 7 - for delivery for use in relation to one or more building units 2. The or each manifold 313 may be further configured to receive liquid (e.g. water) returned from use in relation to the one or more building units 2 via a main heating return conduit 8.

In some embodiments in which a plurality of stratification vessels 31 a (or other form of tank 31 ) is provided, each stratification vessel 31 a (or other form of tank 31 ) is associated with a different service supply unit 4 or a different class or group of service supply unit 4. In some embodiments, a stratification vessel 31 a is associated with one service supply unit 4 but a tank 31 which may not be a stratification vessel 31 a is associated with another service supply unit 4.

As will be understood, therefore, the storage and distribution unit 3 may include a plurality of tanks 31 which may be of different types or configurations and the type/configuration of a particular tank 31 may be dependent on the type of service supply unit 4 with which it is associated.

In some embodiments, such as shown in figures 12 and 13, the stratification vessel 31 a may comprise a vessel of generally cylindrical form with opposing domed ends. The stratification vessel 31 a may include a plurality of feet 316 which are configured to support the vessel above a ground surface. The stratification vessel 31 a may be formed from an upper domed end cap which has been secured (e.g. by welding) to (or which is integrally formed with) an annular wall of the stratification vessel 31 a. A lower domed end cap may be secured (e.g. by welding) to (or which is integrally formed with) the annular wall of the stratification vessel 31 a such that a volume is defined by the upper and lower end caps and the annular wall of the stratification vessel 31 a. The plurality of feet 316 may be secured (e.g. welded or bolted) to the lower domed end cap. In some embodiments, the stratification vessel 31 a is formed in two parts which are secured to each other in a removable manner. As such, the annular wall of the stratification vessel 31 a may comprise two annular wall sections (one section being secured to the upper domed end cap and the other section being secured to the lower domed end cap respectively). Adjacent edges of the two parts of the stratification vessel 31 a may, in such embodiments, carry respective flanges 317 which are useable to secure to the parts together. As such, each flange 317 may include a set of through holes which are configured to align with each other such that a bolt may be passed through both flanges and secured with a nut in order to hold the two parts of the stratification vessel 31 a together. In other embodiments, the stratification vessel 31 a does not comprise two parts or comprises two parts which are secured together in a different manner (e.g. by welding) - such embodiments may not include the flanges 317.

In some embodiments, the input and output pipes 314 comprise tubular members 3141 which may carry a flange at one or both ends to enable connection to other pipework (for example). Each tubule member 3141 extends from outside of the stratification vessel 31 a through a wall of the stratification vessel 31 a (e.g. through the annular wall) and into the volume which is defined by the stratification vessel 31 a. In some embodiments, arrangements are provided to allow the stratification vessel 31 a to be moved into position - e.g. one or more attachment members 318 may be provided on the upper domed end cap (or some other part of the stratification vessel 31 a). The or each attachment member 318 may be configured to receive a hook or the like for lifting the stratification vessel 31 a.

The or each temperature sensor 312 and/or the or each pressure sensor 315 may be configured to be fitted to a respective sensor port 319 (e.g. a tubular sensor port) which extends through a wall of the stratification vessel 31 a (e.g. through the annular wall of the vessel or through the upper or lower domed end cap). The or each sensor port 319 . _

19

comprises a port which is configured to receive at least part of one of the temperature or pressure sensors 312,315, to provide that sensor 312,315 with access to the volume defined by the stratification vessel 31 a so that the sensor 312,315 can operate (i.e. measure a temperature or pressure, as the case may be, of fluid within the stratification vessel 31 a).

In some embodiments, a plurality of sensor ports 319 is provided such that the sensor ports 319 which are spaced apart along a length of the stratification vessel 31 a. In such an arrangement, sensors 312,315 received by the sensor ports 319 may be configured to sense the temperature and/or pressure (as the case may be) of the fluid within the stratification vessel 31 a at various different positions along the length of the stratification vessel 31 a (as defined by the positions of the sensor ports 319). Two or more sensor ports 319 so arranged may be referred to as an array of sensor ports 319 (and the received sensors as an array of sensors 312,325).

In some embodiments, one or more of the sensor ports 319 may be located through the upper or lower domed end cap (or both). A sensor port 319 through the upper or lower domed end cap may be configured to receive a pressure sensor 315 but could be configured to receive a temperature sensor 312.

In some embodiments, any single sensor port 319 may be configured to receive both a temperature sensor 312 and a pressure sensor 315 together (i.e. at the same time) - e.g. a combined temperature and pressure sensor. In some embodiments, the temperature sensor 312 and/or pressure sensor 315 may comprise a plurality of such sensors (and the plurality may include a mixture of temperature and pressure sensors) which is configured to measure the temperature and/or pressure at a corresponding plurality of locations.

In some embodiments, the or each temperature sensor 312 may be configured to measure a parameter indicative of the temperature of the liquid in the stratification vessel 31 a (this may be a temperature of a part of the stratification vessel 31 a for example). The or each temperature sensor 312 may be configured to measure a parameter indicative of the temperature of the liquid in the stratification vessel 31 a remotely (e.g. without contacting the stratification vessel 31 a or the liquid in the _2Q stratification vessel 31 a). For example, the or each temperature sensor 312 may include a thermal imaging device configured to measure a parameter indicative of a temperature of a part of the stratification vessel 31 a which is, in turn, indicative of a temperature of the liquid in the stratification vessel 31 a.

In some embodiments, the or each temperature sensor 312 is configured to be clipped, adhered, or otherwise attached (e.g. through the use of one or more magnets), to an outer wall of the stratification vessel 31 a. In such embodiments, the or each temperature sensor 312 may be configured to measure a parameter indicative of a temperature of the outer wall of the stratification vessel 31 a (which may, in turn, be indicative of a temperature of the liquid in the stratification vessel 31 a). In such embodiments, sensor ports 319 need not be provided.

In some embodiments, the or each sensor port 319 may include a tubular insert such that the or each sensor port 319 is a tubular sensor port 319.

In some embodiments, the or each sensor port 319 includes an attachment arrangement to allow a temperature or pressure sensor 312,315 (or a combined sensor) to be secured thereto. For example, an inner surface of the sensor port 319 may be threaded and configured to mate with a corresponding outer thread on a sensor 312,315. Other attachment arrangements are also possible.

In some embodiments, each of the one or more baffles 31 1 may be an annular baffle 31 1 a - see figure 14, for example. The annular baffle 31 1 a may comprise an annular plate which has an outer circumference which is configured to be secured to an inner surface of the stratification vessel 31 a. An outer edge of the annular baffle 31 1 a may, therefore, have a diameter which is substantially equal to an inner diameter of the stratification vessel 31 a. The annular baffle 31 1 a may, when secured to a wall of the stratification vessel 31 a, be configured to extend into the volume defined by the stratification vessel 31 a. This extension may be substantially perpendicular to the longitudinal axis of the stratification vessel 31 a. The annular baffle 31 1 a may be substantially planar. The annular baffle 31 1 a may be curved such that the annular baffle 31 1 a is partially helical in form. In some embodiments, the annular baffle 31 1 a includes one or more breaks and may comprise one or more individual members (or _n .

21

one member with a single break). In other embodiments, the annular baffle 31 1 a is a substantially continuous annular plate.

In some embodiments, the stratification vessel 31 a may include one or more other plates within the stratification vessel 31 a. For example, a base plate may be provided which is located towards or at the bottom of the volume defined by the stratification vessel 31 a. Similarly, an upper plate may be located towards or at the top of the volume defined by the stratification vessel 31 a. In some embodiments, therefore, a plurality of service supply units 4 is provided. Each service supply unit 4 may be configured to heat liquid (e.g. water) for supply to one tank 31 (e.g. stratification vessel 31 a). As each service supply unit 4 may be configured to heat liquid (e.g. water) to a different temperature, the transfer of heated liquid (e.g. water) between the tanks 31 (through the manifolds 313) allows the temperature in each tank 31 to be controlled. In some embodiments, each service supply unit 4 may be configured to heat liquid (e.g. water) for supply to a common tank 31 (e.g. a stratification vessel 31 a as described above). This may allow a single tank 31 to be provided in place of the two tanks 31 of other embodiments. In some embodiments, the or each service supply unit 4 is configured to heat liquid (e.g. water) and, as such, colder liquid (i.e. liquid at a lower temperature than the heated liquid output by the service supply unit 4) may be delivered from a tank 31 (e.g. stratification vessel 31 a) to the service supply unit 4. The service supply unit 4 may be configured to heat the liquid (e.g. water) and to return the heated liquid to the tank 31 (e.g. stratification vessel 31 a). The extraction of liquid from the tank 31 (e.g. stratification vessel 31 a) and its return may be via the associated manifold 313. As will be appreciated, therefore, the or each service supply unit 4 may include one or more heating mechanisms 43 in some embodiments. As will be appreciated, the liquid (e.g. water) for each service supply unit 4 may be taken from and returned to a common tank 31 (e.g. a stratification vessel 31 a). This may be the only tank 31 in the system from which liquid is taken for heating and/or to which heated liquid is returned. As will become apparent, in some embodiments, the operation of the or each service supply unit 4 is such that efficiency of the or each service supply unit 4 is dependent on the temperature of the liquid (e.g. water) which is supplied to the service supply unit 4 for heating. As such, the use of one or more tanks 31 and associated manifolds 313, may allow one or more service supply units 4 to operate more efficiently than would otherwise be possible.

The or each service supply unit 4 could take a number of different forms and configurations. The or each service supply unit 4 may include control equipment 16 which is configured to control the operation of the service supply unit 4.

In some embodiments, at least two service supply units 4 are provided. The at least two service supply units 4 include at least one first service supply unit 41 and at least one second service supply unit 42.

The at least one first service supply unit 41 may be configured to heat liquid (e.g. water) in a reliable and/or on-demand manner to a substantially consistent temperature. The at least one second service supply unit 42 may be configured to heat liquid (e.g. water) in a less reliable manner and/or to heat liquid (e.g. water) in a less consistent manner and/or to heat liquid (e.g. water) in more efficient (or environmentally friendly) manner and/or to heat liquid (e.g. water) in a slower manner and/or to heat liquid (e.g. water) to a different (hotter or cooler) temperature and/or to provide heated liquid (e.g. water) at a different rate and/or to heat liquid (e.g. water) at a different cost and/or have a different availability, than the first service supply unit 41 .

For example, the first service supply unit 41 may include a boiler (as a heating mechanism 43) which is configured to burn natural gas or oil in order to heat liquid (e.g. water) supplied to the boiler. The boiler may be a condensing-type boiler - the operation of which is known to those skilled in the art. Accordingly, if there is a supply of natural gas or oil, then the boiler provides a reliable and on-demand mechanism by which to heat liquid (e.g. water) to a substantially predetermined temperature. The or each boiler (there may be an array of such boilers provided) may be a 100kW-1 MW boiler (in some embodiments, each boiler is a 100kW boiler). In some embodiments, the or each boiler is a 200-500kW boiler or a 250-300kW boiler. There may, in some embodiments, be three or more boilers. In some embodiments in which an array of boilers is provided, then the total power of the array of boilers may be 250kW or 300kW or greater - for example, the total power of the array may be 300kW and the array may comprise three 100kW boilers.

In some embodiments, the first service supply unit 41 may include an electrically operated heater (as a heating mechanism 43). The electrically operated heater may include a heating element which is configured to heat the liquid to be heated when it receives electrical power.

The second service supply unit 42 may comprise (as a heating mechanism 43) a renewable energy unit - such as one or more solar panels. The renewal energy unit may be such that liquid (e.g. water) is not heated reliably and/or consistently - the level of heating depending on the availability of the renewable energy source (e.g. sunlight).

The second supply unit 42 may include (as a heating mechanism 43) one or more solar panels, and/or one or more biomass generators, and/or one or more gas absorption heat pumps, and/or one or more ground source heat pumps and/or one or more internal combustion engines and/or a hydraulic power plant and/or a wind power plant and/or a district heating system and/or an air source heat pump and/or an electrically operated heater and/or a solar thermal collector and/or a photovoltaic panel. The second supply unit 42 may comprise a combination of different forms of heating mechanism 43.

In some embodiments, the second service supply unit 42 is such that the volume of liquid (e.g. water) which can be heated is not as great as can be heated by the first service supply unit 41 over the same period of time - i.e. the second service supply unit 42 has a lower liquid heating rate.

In some embodiments, the second service supply unit 42 is such that the liquid heating rate is similar to that of the first service supply unit 41 during continuous operation but the second service supply unit 42 takes longer to reach that rate compared to the first service supply unit 41 - i.e. the reaction time to a heating demand is longer for the second supply unit 42. ^ .

24

In some embodiments, the second service supply unit 42 uses a fuel to heat liquid and the first service supply unit 41 also uses a fuel to heat liquid (which may be a different fuel or the same fuel). However, the second service supply unit 42 may be configured to heat liquid less expensively and/or in a more energy efficient manner and/or in a more environmentally friendly manner (e.g. lower harmful emissions) and/or to heat liquid (e.g. water) in a less reliable manner and/or to heat liquid (e.g. water) in a less consistent manner and/or to heat liquid (e.g. water) in more efficient (or environmentally friendly) manner and/or to heat liquid (e.g. water) in a slower manner and/or to heat liquid (e.g. water) to a different (hotter or cooler) temperature and/or to provide heated liquid (e.g. water) at a different rate and/or to heat liquid (e.g. water) at a different cost and/or have a different availability, than the first service supply unit 41 .

In some embodiments, the second service supply unit 42 is configured to heat liquid (e.g. water) to a lower temperature than the first service supply unit 41 .

In other words, in embodiments, the first and the second service supply units 41 ,42 may have different liquid heating characteristics (such as capacities, rates, abilities, and cost of operation). Embodiments may use these different heating characteristics to provide more efficient and/or environmentally friendly operation to heat liquid to meet a demand for heated liquid.

Accordingly, in some embodiments, the first and second service supply units 41 ,42 are configured such that one service supply unit 41/42 may be used to aid in improving the efficient operation of the other service supply unit 41/42. This may be achieved by the use of one or more tanks 31 (e.g. stratification vessels 31 a). As such, one service supply unit 41/42 may be configured to heat liquid (e.g. water) for supply to a tank 31 (e.g. stratification vessel 31 a). The heated liquid in that tank 31 (e.g. stratification vessel 31 a) may then be used to aid in improving the efficiency of the other service supply unit 41/42. For example, liquid (e.g. water) heated by the second service supply unit 42 may be used to ensure that liquid which passed to the first service supply unit 41 for heating is at temperature to aid efficiency of the first service supply unit 41 (e.g. in some embodiments, to keep a condensing boiler of the first service supply unit 41 operating in a condensing mode of operation). „

25

In some embodiments, the second service supply unit 42 may be used during periods of low demand and the first service supply unit 41 may be used during periods of high demand. In some embodiments, during periods of high demand, both the first and second service supply units 41 ,42 are used. In some embodiments, the first service supply unit 41 is used at times when operation of the second service supply unit 42 is not possible - e.g. due to environmental conditions, the position of the sun with respect to the second service supply unit 42, during maintenance, and the like.

Each service supply unit 4 may comprise a number of heating mechanisms/systems 43 (e.g. solar panels, boilers, gas absorption heat pumps, biomass generators, ground source heat pumps, internal combustion engines) which are connected together in series or in parallel with respect to each other. In other words, they may each heat a portion of the liquid or they may each heat substantially all of the liquid. The operation of a plurality of heating mechanisms 43 in a service supply unit 4 (which may be a plurality of heating mechanisms 43 of the same type), may be such that the number of mechanisms 43 operating to heat the liquid is approximately proportional to the demand - in other words, a single heating mechanism 43 may be sufficient for a period of low demand but additional heating mechanisms 43 may need to operate for periods of higher demand. This cascaded operation of the heating mechanisms 43 of each service supply unit 4 may be controlled by the control equipment 16 which is associated with the service supply unit 4.

The main heating output conduit 7 and main heating return conduit 8 are, as discussed above, configured to transfer heated liquid from at least one tank 31 for use by one or more building units 2 and to return liquid from the one or more building units 2. Accordingly, the main heating output conduit 7 and main heating return conduit 8 are both connected in liquid communication with the distribution system 5.

In embodiments, the distribution system 5 is a substantially closed-loop system such that liquid which is delivered through the main heating output conduit 7 is returned through the main heating return conduit 8 during normal operation (i.e. the liquid is not typically lost from the distribution system 5 or consumed by the building unit or units 2). ^

26

The distribution system 5, therefore, comprises a network of pipework 51 forming a circuit between the main heating output conduit 7 and the main heating return conduit 8.

Coupled to the network of pipework 51 are, in embodiments, one or more heat transfer units 52 of the distribution system 5. In some embodiments, the or each heat transfer unit 52 is associated with a single building unit 2. In other embodiments, a plurality of heat transfer units 52 may be provided for a single building unit 2. In other embodiments, a single heat transfer unit 52 is associated with a plurality of building units 2 (e.g. with all of the building units 2 on one floor of the building 1 ).

The or each heat transfer unit 52 is coupled to the network of pipework 51 such that the or each heat transfer unit 52 is configured to receive liquid from the main heating output conduit 7 (i.e. heated liquid) and to return the received liquid to the main heating return conduit 8 - this may be achieved via other parts of the network of pipework 51 , as will become apparent. In embodiments, a plurality of heat transfer units 52 is provided and the heat transfer units 52 may be connected in parallel with each other to the network of pipework 51 .

As will be appreciated, therefore, the network of pipework 51 generally includes a distribution output conduit 51 1 which is coupled in liquid communication with the main heating output conduit 7 and a distribution return conduit 512 which is coupled in liquid communication with the main heating return conduit 8. One or more heat transfer units 52 are coupled to provide liquid communication between the distribution output conduit 51 1 and the distribution input conduit 512.

In some embodiments, a heat transfer unit 51 comprises one or more heat exchangers 521 . In some embodiments, the one or more heat exchangers 521 include a hot water heat exchanger 521 a and/or a heating heat exchanger 521 b. The one or more heat exchangers 521 are each configured to receive liquid (e.g. water) from the distribution output conduit 51 1 and to return liquid to (or towards) the distribution return conduit 512. The one or more heat exchangers 521 are each, therefore, in liquid communication with the distribution system 5 (and, in particular, in some embodiments, with the network of pipework 51 (such as both the distribution output conduit 51 1 and the distribution return conduit 512).

In some embodiments, the or each heat exchanger 521 includes a first heat exchanger conduit 521 1 and a second heat exchanger conduit 5212. The first heat exchanger conduit 521 1 and second heat exchanger conduit 5212 are separate conduits without liquid communication between the two conduits 521 1 ,5212. However, the first and second heat exchanger conduits 521 1 ,5212 are configured such that there is thermal communication between the two conduits 521 1 ,5212.

The first heat exchanger conduit 521 1 , in such embodiments, provides at least part of the liquid communication between the distribution output conduit 51 1 and the distribution return conduit 512. In some embodiments, the second heat exchanger conduit 5212, is configured to receive water from a main water supply 9 and to deliver (via the second heat exchanger conduit 5212) that water to a building unit hot water supply output 10. The thermal communication between the first and second heat exchanger conduits 521 1 ,5212 may be used to transfer heat from the liquid passing through the first heat exchanger conduit 521 1 to water passing through the second heat exchanger conduit 5212. In such an embodiment, therefore, the heat exchanger 521 may be a hot water heat exchanger 521 a which is configured to heat water from a main water supply 9 for delivery to the building unit hot water supply output 10 (for use in building unit 2 or units 2 associated with the heat transfer unit 52). As will be appreciated, that water will, once it has passed through the heat transfer unit 52 from the main water supply 9 to the building unit hot water supply output 10, not be returned to the heat transfer unit 52 during normal operation. One or more non-return valves may be provided in order to inhibit or substantially prevent the flow of water from the building unit hot water supply output 10 to the main water supply 9 (but to permit the flow of water in the opposing direction).

Water which has been delivered to the building unit hot water supply output 10 may then be supplied to the building unit 2 or units 2 associated with the heat transfer unit 52 for use. ₀

For example, the building unit 2 or units 2 may have fitted therein a building unit pumping system 21 to distribute the water to one or more appliances, taps (i.e. faucets), and the like. The water may be used for washing or other cleaning purposes, for example.

Appliances might include dishwashers, washing machines, pressure washers, and the like. Taps (i.e. faucets) might be provided in a kitchen or bathroom, for example, and may include taps associated with sinks, basins, baths, showers, and the like. In such embodiments, the second heat exchanger conduit 5212 is a conduit of a hot water heat exchanger 521 a of the heat transfer unit 52. This configuration may, in some embodiments, provide hot water of about 50°C (e.g. 45-55°C).

In some embodiments, the second heat exchanger conduit 5212, is configured to receive water from a building unit heating system 22 (e.g. from a building heating system return 221 ) - see Figures 3, 7, and 9, for example - and to deliver water back to the building unit heating system 22 (e.g. to a building unit heating system output 222) via the second heat exchanger conduit 5212. The building unit heating system 22 may provide a substantially closed loop between the building unit heating system output 222 and the building system heating system return 221 , and may include one or more building unit heating members 223 (such as radiators).

The building unit heating system 22, therefore, provides a conduit for the flow of water from the building unit heating system output 222 to the building unit heating system return 221 via one or more building unit heating members 223 - such as one or more radiators.

The or each building unit heating member 223 may be provided with an individual controller in the form of a valve which inhibits or substantially prevents the flow of water through the building unit heating member 223 in a controllable manner - such as a thermostatic radiator valve. _2g

Of course, the building unit heating system 22 may be in liquid communication with a building unit cold water supply 1 1 or with the main water supply 9, to allow the water within the building unit heating system 22 to be topped-up, etc. In such embodiments, the second heat exchanger conduit 5212 is a conduit of a heating heat exchanger 521 b of the heat transfer unit 52.

As will be appreciated, the heat transfer unit 52 may include two heat exchangers 521 : a hot water heat exchanger 521 a and a heating heat exchanger 521 b. As such two services (hot water and heating) may be provided to the building unit 2 or units 2. In some embodiments, only one service is to be provided or more than two services may be provided, and there may be a corresponding number and type of heat exchangers 521 .

The heat transfer unit 52 may, in some embodiments, further include one or more metering devices 522. In some embodiments, there is a metering device 522 associated with each respective heat exchanger 521 . The or each metering device 52 is configured to measure the a parameter indicative of the amount of heat which is transferred through the associated heat exchanger 521 and delivered for use in the building unit or units 2.

In some embodiments, the or each metering device 522 may comprise a flow sensor which is configured to measure the volume of water passing through, for example, the building unit hot water supply output 10 and/or the building unit heating system output 222. In some embodiments, the or each metering device 522 may further comprise a temperature sensor (or a plurality of such sensors) which are configured to measure the temperature of water passing though, for example, the building unit hot water supply output and/or the building unit heating system output 222. The or each metering device 522 may be configured to output an electrical signal indicative of the measured parameter and/or to move a mechanical dial and/or use the measured parameters (e.g. flow and/or temperature and/or pressure) to determine a measure of the heat energy consumed. The electrical signal may be wirelessly communicated to the control system 6 or may be communicated to the control system 6 _3Q via a wired communication network - either electrically or optically (e.g. using an optical fibre communication network).

In some embodiments, the heat transfer unit 52 may include an automatic bypass which is configured to pass liquid from the distribution output conduit 51 1 to the distribution return conduit 512 during periods in which there is no such flow through the or each heat exchanger 521 . This helps to avoid lags in the provision of hot liquid to the or each heat exchanger 521 on demand. In some embodiments, a plurality of heat transfer units 52 is provided and the heat transfer units 52 may be connected differently to the manner described above, however, the operation and other components are the same as described above.

In such embodiments, the network of pipework 51 generally includes a distribution output conduit 51 1 which is coupled in liquid communication with the main heating output conduit 7 and a distribution return conduit 512 which is coupled in liquid communication with the main heating return conduit 8. The distribution output conduit 51 1 and the distribution return conduit 512 are however, in such embodiments, connected together in liquid communication - for example via a pipe which may or may not include a valve to control the flow of liquid therethrough. The or each heat transfer unit 52 is coupled to receive liquid from the distribution output conduit 51 1 and to return liquid to the distribution output conduit 51 1 - that liquid then passing on to the distribution return conduit 512. Such an embodiment is shown in figures 15 and 16. As can be seen liquid passing through the distribution output conduit 51 1 may be drawn off into a first heat transfer unit 52 and then returned to the distribution output conduit 51 1 downstream of where the liquid was drawn off. Liquid may also bypass the first heat transfer unit 52 if it is not drawn off (i.e. it continues to flow through the distribution output conduit 51 1 ). Liquid passing through the distribution output conduit 51 1 may be drawn off by a second heat transfer unit 52 (which is downstream of the first heat transfer unit 52). The liquid which is drawn off by the second heat transfer unit 52 may be liquid which was previously drawn off and returned by the first heat transfer unit 52 or may be liquid which bypassed the first heat transfer unit 52. Accordingly, liquid does not need to flow through any particular heat transfer unit 52 to allow a downstream heat transfer unit 52 to operate. More than two heat transfer units 4 may be connected in this manner.

In some embodiments, the distribution system 5 includes a temperature and/or pressure and/or flow sensor 53 which is located at a point in the distribution system which is remote from the distribution pump 513 and/or which is downstream of the last heat transfer unit 52 of the distribution system 5.

The control system 6 is communicatively coupled to various different parts of the embodiments of the system 100 disclosed herein and is configured to communicate control instructions to the control equipment associated with the parts of system 100, in order to control the operation of those parts in accordance with a control strategy.

As will be appreciated, therefore, some parts of embodiments of the system 100 may be provided in a centralised manner and different types of service supply unit 4 may be efficiently integrated for operation together (aided by the use of the storage and distribution unit 3). In the provision of services such as hot water and heating, liquid which has been heated using the service supply unit or units 4 may be used to heat water in the heat transfer unit or units 52 to provide these services on-demand in the building unit 2 or units 2.

In some embodiments, the end-user has some of the advantages of individualised controls and the management-user has some of the advantages of a centralised system.

With the above overview or the core components and parts of embodiments of the system 100 in mind, those parts and components will now be considered in more detail in accordance with various embodiments of the invention. With reference to figures 5 and 6, in some embodiments, the one or more service supply units 4 includes one or more boilers which may act as a first service supply unit 41 as discussed above. The or each boiler may be a natural gas, oil, or other fossil fuel (or hydrocarbon) based boiler. The or each boiler may be a condensing boiler which operates, as will be appreciated, to scavenge additional heat from the exhaust gases - causing water vapour in those exhaust gases to condense.

In some embodiments, there is a plurality of such boilers which is connected and operated in a cascade arrangement (i.e. in series with boilers being brought online in accordance with control instructions from the control equipment associated with the boilers).

Although several embodiments are discussed with reference to the figures with the heating mechanisms 43 of the service supply unit or units 4 being one or more boilers, other heating mechanisms 43 could be used in substantially the same configuration (as is described above).

The or each boiler may, therefore, be connected to a common input conduit 41 1 and a common output conduit 412. The common input and output conduits 41 1 ,412 are connected in liquid communication with the storage and distribution unit 3, for example to a first tank 31 (see figure 4) of the one or more tanks 31 . The first tank 31 may or may not be a stratification vessel 31 a as described above. The common input conduit 41 1 may be connected to the first tank 31 to collect liquid (e.g. water) from a lower portion of the first tank 31 . This will usually be the coldest water in the first tank 31 .

The common input conduit 41 1 may be connected in liquid communication, in some embodiments, to input conduit or conduits of the or each boiler. The or each boiler is configured to receive liquid to be heated from the common input conduit 41 1 (i.e. from the storage and distribution unit 3 (e.g. from the first tank 31 )) and to heat that liquid before returning the heated liquid, via an output conduit or conduits of the or each boiler, to the common output conduit 412.

The common input conduit 41 1 may be associated with a common input conduit temperature sensor 41 1 1 and/or a common input conduit pressure sensor 41 12 located between the storage and distribution unit 3 (e.g. first tank 31 ) and the boiler or boilers along the flow path of liquid through the common input conduit 41 1 . The common input ^ conduit temperature sensor 41 1 1 and/or pressure sensor 41 12 may be configured to output a signal representative of the temperature and/or pressure of the liquid within the common input conduit 41 1 . This signal may be an electrical signal which is provided to the control equipment 16 associated with the service supply unit or units 4 of which the boiler or boilers form a part.

In some embodiments, a common input conduit flow and/or pressure meter 41 13 is also provided in the common input conduit 41 1 between the storage and distribution unit 3 (e.g. the first tank 31 ) and the boiler or boilers along the flow path of the liquid through the common input conduit 41 1 . The common input conduit flow and/or pressure meter 41 13 may be configured to output a signal representative of the volume of liquid which has flowed along the common input conduit 41 1 . This signal may be an electrical signal which is provided to the control equipment 16 associated with the service supply unit or units 4 of which the boiler or boilers form a part.

The or each boiler may further include isolation valves in both the input conduit or conduits of the boiler and in the output conduit or conduits of the boiler - the isolation valves being configured to selectively isolate the boiler from the common input conduit 41 1 and the common output conduit 412.

The or each boiler may further include its own temperature and/or pressure sensors. For example, a boiler input temperature sensor 41 14 may be provided to measure the temperature of the liquid entering the boiler and to provide that measurement to the control equipment associated with the service supply unit or units 4. Similarly, a boiler output temperature sensor 41 15 and boiler output pressure sensor 41 16 may be provided to measure the temperature and pressure of the liquid leaving the boiler and to provide that measurement to the control equipment 16 associated with the service supply unit or units 4. In some embodiments with a plurality of such boilers provided, the boilers of that service supply unit 4 are provided as a single module of boilers (and, in some instances, multiple modules can be interconnected). .

34

The common output conduit 412 may be associated with a common output conduit temperature 4121 and/or a common input conduit pressure sensor 4122 located between the boiler or boilers and the storage and distribution unit 3 (e.g. the first tank 31 ) along the flow path of liquid through the common output conduit 412. The common output conduit temperature 4121 and/or pressure sensor 4122 may be configured to output a signal representative of the temperature and/or pressure of the liquid within the common output conduit 412. This signal may be an electrical signal which is provided to the control equipment 16 associated with the service supply unit or units 4 of which the boiler or boilers form a part.

In embodiments, common input and output conduit isolation valves 41 17,4123 are provided which are configured to isolate the or each boiler from the storage and distribution unit 3 (e.g. the first tank 31 ) selectively. The common output conduit 412 may be connected in liquid communication with the first tank 31 towards an upper portion of the first tank 31 .

As will be appreciated, the connection of the common output conduit 412 and common input conduit 41 1 to the first tank 31 may be via the associated manifold 313 (if provided).

In some embodiments, a respective heat exchanger is provided between each service supply unit (including the first and second service supply units 41 ,42) to isolate the liquid which passes through the service supply units from the heated liquid which is in the tank or tanks 31 .

In such embodiments, the or each boiler includes a pump to cause the circulation of liquid from the storage and distribution unit 3 (e.g. the first tank 31 ) to the or each boiler and back again to the storage and distribution unit 3 (e.g. the first tank 31 ).

In some embodiments, the main heating output conduit 7 (via the manifold 313 or otherwise) is connected in liquid communication with the first tank 31 . This connection may be towards the upper portion of the first tank 31 . The main heating return conduit 8 _r .

35

(via the manifold 313 or otherwise) is connected in liquid communication with the first tank 31 . This connection may be towards the lower portion of the first tank 31.

A distribution output conduit isolation valve 51 1 1 may be provided between the distribution output conduit 51 1 and the storage and distribution unit 3 (e.g. the first tank 31 ) to allow for the selective isolation of the distribution output conduit 51 1 from the storage and distribution unit 3 (e.g. the first tank 31 ). In addition, a distribution output conduit safety valve 51 12 may be provided along the distribution output conduit 51 1 close to the storage and distribution unit 3 (e.g. the first tank 31 ) to allow for the draining of liquid from the distribution output conduit 51 1 and/or the release of liquid pressure within the distribution output conduit 51 1 in the event of an emergency.

A distribution return conduit isolation valve 5121 may be provided between the main heating return conduit 8 (which is in liquid communication with the distribution return conduit 512) and the storage and distribution unit 3 (e.g. the first tank 31 ) to allow for the selective isolation of the main heating return conduit 8 and/or the distribution return conduit 512 from the storage and distribution unit 3 (e.g. the first tank 31 ).

The or each boiler (or other part of the service supply unit 4 or a heating mechanism 43 thereof) is also in fluid communication with a fuel supply conduit 41 18 which is configured to supply fuel to the or each boiler (or other heating mechanism 43) for burning in order to heat the liquid as described herein. The fuel supply conduit 41 18 may be configured to carry natural gas or oil, for example, from a mains supply or supply tank of the fuel. A fuel supply valve 41 19 may be provided to allow the selective control of the supply of fuel to the fuel supply conduit 41 18.

In embodiments, one or more fuel supply metering devices may be provided to measure the volume of fuel used by the or each boiler (or other heating mechanism 43). This may be measured collectively for all boilers or individually for each boiler (or other heating mechanism(s) 43). This information may be provided to the control equipment 16 associated with the service supply unit 4 of which the or each boiler (or other heating mechanism 43) is a part. 36

Isolation valves may be provided to allow isolation of the fuel supply conduit 41 18 from the or each boiler (or other heating mechanism 43).

In some embodiments, the storage and distribution unit 3 includes a second tank 31 (which may or may not be a stratification vessel 31 a as described herein). Whilst the first tank 31 was associated with the one or more boilers (or other heating mechanisms 43) of a first service supply unit 4 (which may act as the first service supply unit 41 ), the second tank 31 is associated with a different, second, service supply unit 4 (which may act as the second service supply unit 42). In some embodiments, the first and second tanks 31 are combined into one stratification vessel 31 a which is associated with both the first and second service supply units 41 ,42 - the description herein should be read accordingly.

The second tank 31 may be connected in liquid communication with the first tank 31 via a selection valve 5122 (which may form part of the associated manifold 313). The selection valve 5122 may be connected in liquid communication with the first tank 31 , the second tank 31 , and the main heating return conduit 8 (which is in liquid communication with the distribution return conduit 512). In some embodiments, the distribution return conduit isolation valve 5121 is located in the liquid flow path between the selection valve 5122 and the first tank 31 . In embodiments, in which the first and second tanks 31 are combined into one stratification vessel 31 a, the selection valve 5122 may be connected in liquid communication with the stratification vessel 31 a and the main heating return conduit 8 and the distribution return conduit isolation valve 5121 may be omitted.

The selection valve 1522 may be configured to connect selectively, in liquid communication, the first tank 31 and the main heating return conduit 8 (which is in liquid communication with the distribution return conduit 512), the first tank 31 and the second tank 31 , and the second tank 31 and the main heating return conduit 8 (which is in liquid communication with the distribution return conduit 512). In embodiments, in which the first and second tanks 31 are combined into one stratification vessel 31 a, the selection valve 1522 may be configured to connect selectively, in liquid communication, the stratification vessel 31 a and the main heating return conduit 8 (which is in liquid communication with the distribution return conduit 512). Operation of the selection ^ valve 1522 may be controlled by the control equipment 16 associated with the first and second tanks 31 and/or the stratification vessel 31 a.

The connection between the second tank 31 and the first tank 31 (or the main heating return conduit 8) may be towards a lower portion of the second tank 31 (and may be via the associated manifold of the first and/or second tank 31 ). The connection of the second tank 31 to the first tank 31 through the selection valve 1522 (if provided) may be a connection between the lower portions of both tanks 31 .

The second tank 31 is also connected in liquid communication with the first tank 31 in a manner which bypasses the selection valve 1522 (of provided). In particular, an upper portion of the second tank 31 may be connected in liquid communication with a lower portion of the first tank 31 (this connection may be via the associated manifolds 313 of the first and/or second tanks 31 ). The connection may also be via the distribution return conduit isolation valve 5121 (through a connection between that valve 5121 and the selection valve 1522 in the liquid flow path between the two).

A second tank distribution return conduit isolation valve 5123 may be provided in the connection between the upper portion of the second tank 31 and the first tank 31 (and/or the distribution return conduit isolation valve 5122). The second tank distribution return conduit isolation valve 5123 is configured to allow isolation of the second tank 31 from the first tank 31 and the main heating return conduit 8 (which is in liquid communication with the distribution return conduit 512) apart from through the selection valve 5123. In embodiments, in which the first and second tanks 31 are combined into one stratification vessel 31 a, the second tank distribution return conduit isolation valve 5123 may be omitted.

The second service supply unit 4 is connected in liquid communication with the storage and distribution unit 3 (e.g. with the second tank 31 or the stratification vessel 31 a). In particular, the second service supply unit 4 may be configured to receive liquid from the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a) via a second common input conduit 423 and to return heated liquid to the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a) via a second common output conduit 424. In some embodiments, the second service supply unit 4 is ₀

oo

configured to receive liquid from the lower portion of the second tank 31 of the storage and distribution unit 3 and to return heated liquid to the upper portion of the second tank 31 . The second service supply unit 4 may include a second service supply unit pump 421 which is configured to pump liquid from the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a) to one or more heating mechanisms 43 of the second service supply unit 4 through the second common input conduit 423. Second service supply unit pump isolation valves 422 may be provided either side of the pump in the flow path of the liquid from the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a) to the one or more heating mechanisms 43. The second service supply unit pump isolation valves 422 may be selectively operable to isolate the second service supply unit pump 421 from one or both of the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a) and the or each heating mechanism 43 of the second service supply unit 4.

The or each heating mechanism 43 of the second service supply unit 4 may be connected in liquid communication with both the second common input conduit 423 and the second common output conduit 424. Liquid may, in such a configuration, pass between the two conduits 423,424 via the or each heating mechanism 43 of the second service supply unit 4.

The or each heating mechanism 43 of the second service supply unit 4 may be as discussed above - e.g. a renewable energy heating mechanism 43 such as one or more solar panels, a biomass generator, a ground source heat pump and/or an air source heat pump.

The or each heating mechanism 43 is configured to receive liquid from the second common input conduit 423, to heat that liquid, and to return the liquid to the second common output conduit 424 (e.g. back to the second tank 31 or the stratification vessel 31 a). _3g

As will be appreciated the or each heating mechanism 43 of the second service supply unit 42 may require fluid communication with the fuel supply conduit 41 18 (or a different fuel supply conduit) which is configured to supply fuel to the or each heating mechanism 43 in order to heat the liquid as described herein. The fuel may not be the same fuel used by the or each boiler of the first service supply unit 4. In some embodiments, the first and/or second service supply unit 41 ,42 may be configured to use (e.g. burn) a hydrocarbon fuel (such as a fossil fuel, natural gas, oil, coal, etc), the fuel may include wood, rape seed oil, and/or waste material from another process. In some embodiments, a second common output conduit metering device 425 may be provided which is configured to measure the volume of liquid flowing through the common output conduit 424 to the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a). In some embodiments, a second common output conduit expansion vessel and safety valve arrangement 426 is provided in the liquid flow path between the or each heating mechanism 43 and the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a) - the arrangement being configured to reduce liquid pressure in the second common output conduit 423. The arrangement 426 may include an associated pressure and/or flow and/or temperature sensor 426a.

In some embodiments, a second common output conduit isolation valve 427 is provided between the storage and distribution unit 3 (e.g. the second tank 31 or the stratification vessel 31 a) and the second common output conduit 423 to allow the second tank 31 (or the stratification vessel 31 a) to be isolated from the second common output conduit 423.

An example of part of an embodiment using a stratification vessel 31 a instead of the first and second tanks 31 described above can be seen in figure 17. With reference to figure 13, which shows a stratification vessel 31 a:

a first 314a of the input and output ports 314 is an input port which is configured to receive liquid from the first service supply unit 41 ;

a second 314b of the input and output ports 314 is an input port which is configured to receive liquid from the second service supply unit 42; a third 314c of the input and output ports 314 is an input port which is configured to receive liquid from the main heating return conduit 8;

a fourth 314d of the input and output ports 314 is an output port which is configured to deliver liquid to the main heating output conduit 7;

a fifth 314e of the input and output ports 314 is an output port which is configured to deliver liquid to the first and/or second service supply unit 41 ,42; and

a sixth 314f of the input and output ports 314 is an output port which is configured to deliver liquid to the first and/or second service supply unit 41 ,42. In some embodiments, the third port 314c is configured alternatively or selectively configured to act as an output port to deliver liquid to the second service supply unit 42 or to the first service supply unit 41 . A valve may be provided and in liquid communication with the third port 314c to provide the selective operation described above.

The first port 314a may be located higher than the other ports 314 in some embodiments (and may be towards the top of the stratification vessel 31 a). In some embodiments, the fifth and sixth ports 314e,f are lower than the other ports 314 (and may be towards the bottom of the stratification vessel 31 a). In some embodiments, the third port 314c is located towards the bottom of the stratification vessel 31 a. The fourth port 413d may be located towards the top of the stratification vessel 31 a (i.e. above the third, fifth and sixth ports 314c,e,f).

In some embodiments, fewer ports 314 may be provided. For example, the fifth and sixth ports 314e,f may be combined into a single port 314.

With reference to figure 18, in some embodiments, the second service supply unit 42 (which may be of the type and form described above) is configured for use in preheating water which is further heated by a building unit hot water heating mechanism 18 for use in the building unit 2. In some such embodiments, the second service supply unit 42 may service (and be associated with) a plurality of building unit hot water heating mechanisms 18 (with one or more building unit hot water heating mechanisms 18 being provided for each of a plurality of building units 2). In some embodiments, the or each . .

41

building unit hot water heating mechanism 18 may be located within or adjacent the building unit 2 with which it is associated.

The or each building unit hot water heating mechanism 18 may include one or more boilers which may be a natural gas, oil, or other fossil fuel (or hydrocarbon) based boiler. The or each boiler may be a condensing boiler which operates, as will be appreciated, to scavenge additional heat from the exhaust gases - causing water vapour in those exhaust gases to condense. In some embodiments, the or each building unit hot water heating mechanism 18 may be electrically operated and may, therefore, include one or more electric heating elements.

In some embodiments, the or each building unit hot water heating mechanism 18 includes one or more building unit hot water heating mechanism tanks 181 for the storage of heated water for use in the building unit 2.

In some embodiments, the second service supply unit 42 is isolated (in terms of liquid communication) from the heated water which is provided to the or each building unit 2 - e.g. by the use of a heat exchanger. Accordingly, the second service supply unit 42 may be configured to heat a liquid and heat from that liquid may be transferred to the water which is provided (as heated water) to the building unit 2.

In some embodiments, the or each second service supply unit 42 is configured to heat a liquid in a pre-heated liquid tank 31 b of the one or more tanks 31 . The or each second service supply unit 42 may be configured to heat a liquid which is passed through a conduit 31 1 b which extends into the pre-heated liquid tank 31 b such that heated liquid passing through the conduit heats another liquid in the pre-heated liquid tank 31 b. The other liquid may be water. The conduit 31 1 b in the pre-heated liquid tank 31 b may be in the form of a coil (or may be a heat exchanger instead). That other liquid may be passed through one or more conduits 182 to the or each building hot water heating mechanism 18. In some embodiments, that other liquid is isolated (in terms of liquid communication) from the heated water which is used in the building unit 2 (e.g. output by one or more taps or the like as described elsewhere herein). This isolation may be . _n

42

achieved by the use of one or more heat exchangers in the or each building unit water heating mechanism 18.

In some embodiments, the liquid which is passed through the one or more conduits 182 to the or each building hot water heating mechanism 18 is isolated (in terms of liquid communication) from the liquid in the pre-heated liquid tank 31 b. In some embodiments, the isolation is achieved by a conduit (which may be the form of a coil) which extends into the pre-heated liquid tank 31 b or a heat exchanger. That conduit or heat exchanger may be configured to receive water from a main water supply 9, such that water passes from the main water supply 9, and through the heat exchanger or conduit before passing to the or each building hot water heating mechanism 18 through the one or more conduits 182.

In such embodiments, the second service supply unit 42 may be configured to heat liquid to a temperature which is below 60°C, or below 50°C (but, in any event, above an ambient temperature).

In some embodiments, the first service supply unit 41 may be configured to supply heated liquid to a high temperature tank 31 c of the one or more tanks 31 . The high temperature tank 31 c is configured to store a liquid at a higher temperature than the pre-heated liquid tank 31 b. One or more additional service supply units 4 may be configured to supply heated liquid to the high temperature tank 31 c in the same manner. The one or more additional service supply units 4 may be connected in parallel to the high temperature tank 31 c (and may be connected in parallel with the first service supply unit 41 ). The first service supply unit 41 and any one or more further service supply units 4 may be configured, in such embodiments, to heat liquid to a temperature above 60°C or above 70°C or above 80°C or above 90°C (but below 100°C). The one or more additional service supply units 4 may include, for example, one or more units with one or more micro-turbine combined heat and power heating mechanisms.

The first service supply unit 41 and the one or more additional service supply units 4 which are connected to the high temperature tank 31 c may be configured to receive liquid to be heated from the high temperature tank 31 c and/or from the pre-heated liquid tank 31 b, and to return the heated liquid to the high temperature tank 31 c. In some embodiments, the main heating output conduit 7 is in liquid communication with the high temperature tank 31 c. In some embodiments, the main heating return conduit 8 is in liquid communication with one or both of the high temperature tank 31 c and the pre-heated liquid tank 31 b. One or more valves may be provided and configured to selectively connect the main heating return conduit 8 to the high temperature tank 31 c or the pre-heated liquid tank 31 b - as will be appreciated the liquid returned via the main heating return conduit 8 will be a lower temperature than the heated liquid. A transfer conduit 312b may be configured to provide liquid communication between the pre-heated liquid tank 31 b and the high temperature tank 31 c. The transfer conduit 312b may link an upper part of the pre-heated liquid tank 31 b to a lower part of the high temperature tank 31 c - i.e. allowing the transfer of the hottest liquid from the pre-heated liquid tank 31 b to mix with the coolest liquid in the high temperature tank 31 c.

As will be appreciated, therefore, the first service supply unit 41 in such embodiments may heat a first portion of the liquid to a first temperature. The second service supply unit 42 may heat a second portion of the liquid to a second temperature which is lower than the first temperature. The first and second portions of the liquid may, however, be parts of the same circulating liquid such that the second portion of the liquid is preheated by the second service supply unit 42 before being passed to the first service supply unit 41 for further heating (as the "first portion of the liquid"). Similarly, the first portion of the liquid (once used to provide heating and, therefore, returned to the storage and distribution unit 3 cooler than the first temperature) may be returned for heating by the second service supply unit 42 (or by the first service supply unit 41 ). Accordingly, one part of the second portion of the liquid may be passed to the or each building hot water heating mechanisms 18 and another part may be passed to the first service supply unit 41 for further heating. In some embodiments, the pre-heated liquid tank 31 b and the high temperature tank 31 c are replaced by a single tank 31 which may be stratification vessel 31 a. In some such embodiments, the stratification vessel 31 a may include one or more heat exchangers and/or conduits (e.g. in the form of a coil) which are used to transfer heat into and out of the stratification vessel 31 a. In some such embodiments, a service supply unit 4 may be provided which includes one or more cooling mechanisms 45 which are configured to chill water (or another liquid) for use in the provision of chilled water to the or each building unit 2.

The cooling mechanism 45 may include any suitable form of refrigeration unit and may be a wet or dry air cooler. The cooling mechanism 45 may be a compressor-based refrigeration unit, an adsorption refrigeration unit, an absorption refrigeration unit. The or each cooling mechanism 45 may be isolated (in terms of liquid communication) from chilled liquid which is provided to the or each building unit 2. This isolation may be achieved by the use of one or more heat exchangers 467. A cold distribution pump 513b may be provided to pump the chilled liquid through a main cooling output conduit 7a for circulation to one or more building units 2. One or more heat exchangers (e.g. in the or each heat transfer unit 52) may be provided to use the chilled liquid to chill water for use in the or each building unit 2. After use, the chilled liquid may be returned via a main cooling return conduit 8a, for re-chilling using the or each cooling mechanism 45.

The distribution system 5 in some embodiments comprises a network of pipework 51 including the distribution output conduit 51 1 and the distribution return conduit 512.

The distribution system 5 may further include a distribution pump 513. The distribution pump 513 is configured to pump liquid through the distribution output conduit 51 1 to the heat transfer unit or units 52. In some embodiments, the distribution pump 513 forms part of the storage and distribution unit 3 instead of the distribution system 5. As will be appreciated, in such embodiments, the distribution pump 513 may be configured to pump liquid through the main heating output conduit 7 (which is in liquid communication with the distribution output conduit 51 1 ) and so the effect and operation of the distribution pump 513 will largely be the same irrespective of whether it forms part of the distribution system 5 or the storage and distribution unit 3.

An upstream distribution pump sensor 5131 and a downstream distribution pump sensor 5132 may be provided either side of the distribution pump 513 with respect to the flow path of liquid through the distribution output conduit 51 1 (or main heating output .

45

conduit 7, as the case may be). The upstream and downstream distribution pump sensors 5131 ,5132 may each be configured to measure a liquid pressure and/or a liquid temperature and/or a liquid flow rate and/or resistance to liquid flow in the distribution output conduit 51 1 (or main heating output conduit 7). The measurements are output to control equipment 16 associated with the distribution pump 513.

In addition, one or more differential distribution conduit pressure sensors 5133 may be configured to measure a differential pressure between the distribution output and return conduits 51 1 ,512 at one or more locations. Again, this information is provided to control equipment 16 for the distribution pump 513.

In some embodiments, distribution output conduit pressure and/or temperature sensors 51 13 are provided downstream of the distribution pump 513 and configured to measure a liquid pressure and/or temperature of the liquid in the distribution output conduit 51 1 . This information may be provided to control equipment as will become apparent.

The distribution return conduit pressure and/or temperature sensors 5124 may also be provided and configured to measure a liquid pressure and/or temperature of the liquid in the distribution return conduit 512. This information may be provided to control equipment 16 as will become apparent.

A distribution return conduit expansion vessel 5125 may be provided and connected in liquid communication with the distribution return conduit 512 to reduce/normalise the liquid pressure in the distribution return conduit 512. As will be understood, the distribution return conduit expansion vessel 5125 could equally be provided in liquid communication with the main heating return conduit 8 to reduce/normalise the liquid pressure in the main heating return conduit 8 (and the vessel 5125 may, therefore, form part of the storage and distribution unit 3 rather than the distribution system 5). A distribution return conduit metering device 5126 may be provided and configured to measure the volume of liquid being returned through the distribution return conduit 512 to the storage and distribution unit 3 (e.g. to the first and/or second tank 31 ). This information may be provided to control equipment 16 as will become apparent. As will be understood, the distribution return conduit metering device 5126 could equally be . _

46

provided to measure the volume of liquid being returned through the main heating return conduit 8 (and the metering device 5126 may, therefore, form part of the storage and distribution unit 3 rather than the distribution system 5). The network of pipework 51 may, as will be appreciated, comprise a main trunk of pipework from which branches of pipework extend - each branch comprising a portion of the distribution output conduit 51 1 and a portion of the distribution return conduit 512. For example, one branch may be provided for each floor in a building 1 . One or more branch valves may be provided to allow a particular branch to be isolated or shut-off.

The or each heat transfer unit 52 may be connected to the distribution output and return conduits 51 1 ,512 and this may be at the main trunk or along one of the branches.

As described above, the heat transfer unit 52 (see figures 7 and 9) may include one or more heat exchangers 521 . The heat transfer unit 52 may also include one or more metering devices 522.

In more detail, the heat transfer unit 52 includes at least one metering device 522 associated with the or each heat exchanger 521 . The or each metering device 522 may be configured to measure the volume of water which passes through the second heat exchanger conduit 5212 for the or each heat exchanger 521.

In some embodiments, a combined metering device 522 is provided to measure the volume of water flowing through more than one heat exchanger 521 (through the second heat exchanger conduits 5212 thereof).

The first and second heat exchanger conduits 521 1 ,5212 may comprise passages between metal plates (the metal plates separating the two conduits 521 1 ,5212. The passages may be tortuous in order to increase the time required for the water to flow through the second heat exchanger conduit 5212 and the time required for the liquid to flow through the first heat exchanger conduit 521 1 . . _,

47

The heat transfer unit 52 may include one or more expansion vessels, pressure regulation devices, and/or the like in order to regulate the pressure within the or each heat exchanger 521 . The heat transfer unit 52 may also include one or more pressure or temperature sensors to measure the liquid pressure and/or temperature in the or each heat exchanger 521 , for example, and to pass this information to control equipment 16 of the heat transfer unit 52. The heat transfer unit 52 may include, in some embodiments, a thermostat 523 which is connected to control equipment 16 of the heat transfer unit 52. The thermostat 523 may be remote from the or each heat exchanger 521 (as will become apparent) and may be configured to measure the ambient temperature in the whole or a part of the building unit 2 associated with than heat transfer unit 52. Accordingly, the control equipment 16 associated with the heat transfer unit 52 may use a set point temperature and the measurement by the thermostat 523 to determine whether or not to heat water using a heating heat exchanger 521 b of the heat transfer unit 52.

The heat transfer unit 52 may include, in some embodiments, a clock 524 which is configured to monitor the current time and to provide this information to the control equipment 16 associated with the heat transfer unit 52.

The clock 524 may be remote from the or each heat exchanger 521 (as will become apparent) and may be part of a controller which forms part of the control equipment 16 associated with the heat transfer unit 52. The controller may include a user interface and a memory. The controller may be configured to permit an end-user to interact with the controller to set an operating program for the heat transfer unit 52 (e.g. for the scheduled provision of heating and/or hot water) - as is known in the art. The heat transfer unit 52 may include a heat transfer unit safety valve and drain 525 configured to allow water within the heat transfer unit 52 to be drained in an emergency.

The heat transfer unit 52 may be configured such that it can be plugged into and out of the building unit heating system return 221 and output 222, the main water supply 9, the building unit hot water supply output 10, the distribution output conduit 51 1 , and/or the distribution return conduit 512. Accordingly, each such conduit, etc., may be provided with a respective plug or socket arrangement which is configured to mate with a corresponding plug or socket arrangement of the heat transfer unit 52 and/or each may be provided is an isolation valve 526.

The heat transfer unit 52 may also include a shut-off valve 527. The shut-off valve 527 may be configured for remote actuation and operable to inhibit or substantially prevent the heat transfer unit 52 from operating. For example, the shut-off valve 527 may be configured to inhibit or substantially prevent the flow of liquid from the distribution output conduit 51 1 to the rest of the heat transfer unit 52 (e.g. to the or each heat exchanger 521 ). The shut-off valve 527 may also act as a pressure or flow regulation valve. The shut-off valve 527 may include a pressure independent controlled valve which is configured to deliver a substantially constant flow rate of liquid through the valve irrespective of the liquid pressure in the distribution output conduit 51 1 . The shut-off valve 527 may, in some embodiments, not be configured to prevent the flow of liquid to the rest of the heat transfer unit but may still act as a pressure independent controlled valve. As such, the shut-off valve 527 may, in some embodiments, be a pressure independent controlled valve rather than a shut-off valve as such.

In some embodiments, a modularly constructed plant room 200 is provided. The modularly constructed plant room 200 may comprise a steel framework to which are attached a plurality of panels. The panels are attached in a removable manner such that individual panels may be removed and replaced without damage to the other panels or to the steel framework.

The modularly constructed plant room 200 may be configured to house one or more of: the storage and distribution unit (including the one or more tanks), and at least one service supply unit 4 (such as the first service supply unit 41 ). In some embodiments, the modularly constructed plant room 200 may also house at least some of the control equipment 16 discussed herein and may house at least part of the control system 6 - see below. In some embodiments, the modularly constructed plant room 200 is also configured to house the distribution pump 513 of the distribution system 5. The modularly constructed plant room 200 may house the distribution return conduit expansion vessel 5125.

In accordance with an embodiment, there is a method provided for the construction of a plant room which comprises the provision of steel framework of the modularly constructed plant room 200, the installation of at least some (if not all) of the aforementioned components which may be housed in the modularly constructed plant room 200 and then the attachment of the plurality of panels. In some embodiments, installation of the components in the steel framework (which may include a base) occurs remote from the building 1 to which the system 100 is to be fitted and the plurality of panels is attached once the rest of the modularly constructed plant room 200 has been installed in, on, or next to the building 1 . As will be appreciated, therefore, a large part of the system 100 may be prepared and even commissioned offsite - minimising disruption at the building 1 .

The modularly constructed plant room 200 may be positioned with respect to the building 1 which it is intended to service in relatively close proximity thereto. For example, the modularly constructed plant room 200 may be placed on the roof of the building 1 or in the grounds adjacent the building 1.

The steel framework, therefore, may include attachment points for a crane to allow the modularly constructed plant room 200 to be hoisted into position by a crane. The attachment points may each include one or more eyebolts.

In some embodiments, a base of the steel framework comprises a plurality of sections which are secured together to form the base. The steel framework may be constructed out of galvanised steel.

The panels of the modularly constructed plant room 200 may be selected so that their appearance matches that of the building 1 on or adjacent to which the modularly constructed plant room 200 is to be located. The heat transfer unit or units 52 may be located outside of the confines of the building unit or units 2 with which they are associated. For example, the heat transfer unit 52 for an apartment may be located outside of the apartment in a communal part of the building 1 .

As will be appreciated, other than the necessary pumping within the building unit 2, and potentially the thermostat 523 and/or clock 524 in some embodiments, the aforementioned construction allows the majority of the parts of the system to be located in areas of the building 1 which are readily accessible by, for example, the management-user (potentially without the need to obtain the end-user's consent). As such, maintenance work can be performed more efficiently because access to individual building units 2 is not normally necessary. As will be appreciated, during the commissioning process for the bulk of the system 100, it would be necessary to connect the heat transfer units 52 in respect of each building unit 2. Full load testing could only then be assessed by creating demand for hot water and/or heating. In a large building this would be impractical. Therefore, in accordance with some embodiments, the or each heat transfer unit 52 is provided with connections for a bypass pipe 528 (which may be a flexible pipe). The connections are configured to mate with corresponding connections on either end of a bypass pipe 528 which may comprise a section of flexible pipe or hose. The connections may, therefore, be male or female threaded or bayonet-type connections. The connections for the bypass pipe 528 are in liquid communication with the distribution output conduit 51 1 and the distribution return conduit 512. The bypass pipe 528 (when connected) may provide a constricted flow path between the distributed output conduit 51 1 and the distributed return conduit 512, through at least part of the heat transfer unit 52. As such, with a bypass pipe 528 fitted to the or each heat transfer unit 52, liquid will flow between the distributed output conduit 51 1 and the distributed return conduit 512. The constricted flow path provided by each such bypass pipe 528 mimics the flow of liquid through one or more heat exchangers 521 of the heat transfer unit 52 and, therefore, this mimics use of the heat transfer unit 52 for the supply of hot .. .

51

water and/or heating to the building unit 2. The system 100 can then be commissioned and tested.

In some embodiments, the connections for the bypass pipe 528 are configured such that the bypass pipe 528 (when fitted) provides a constricted flow path between the second heat exchanger conduit 5212 downstream of the heat exchanger 521 of which it is a part and a drain or the second heat exchanger conduit 5212 upstream of the heat exchanger 521 of which it is a part. Accordingly, the constricted flow path provided by such a bypass pipe 528 may mimic flow of hot water to the building unit hot water supply output 10 or through the building unit heating system output 222, the building unit heating system return 221 , and the building unit heating member or members 223. The system 100 can then be commissioned and tested.

A plurality of such connections may be provided to allow multiple bypass pipes 528 to be used with a single heat transfer unit 52 - to mimic the operation thereof in the provision of more than one service (e.g. both hot water and heating).

In some embodiments the connections for the bypass pipes 528 may include connections of the heat transfer unit 52 for the building unit heating system output and/or return 222,221 , and/or the building unit hot water supply output 10.

Once this process is complete, the bypass pipe(s) 528 can be removed from the or each heat transfer unit 52. In embodiments, the connections for the bypass pipe 528 are provided with valves to inhibit or substantially prevent the flow of liquid therethrough when the bypass pipe(s) 528 is not connected thereto.

Aspects of embodiments of the control system 6 will now be described in more detail.

The control system 6 may include the control equipment 16 which has been discussed above or may be separate from that control equipment 16. The aforementioned control equipment 16 may, for example, be configured to receive one or more instructions from the control system 6 and may then control the parts and components of embodiments to implement the instructions provided by the control system 6. „

52

The control system 6 may be at least partially housed in the modularly constructed plant room 200 (if provided) or another form of plant room as the case may be. In some embodiments, some of the operations and aspects of the control system 6 are provided remote from the building 1 to which the system 100 has been installed.

As will be appreciated, some of the operations of the control system 6 may be implemented by a computer system. Embodiments of the present invention, therefore, include a computer program which, when executed, causes the operations of the control system 6 to occur. Embodiments, also include a computer readable medium including such a computer program and a computer programmed with the computer program.

The control system 6 is configured to receive information from the various temperature and pressure sensors which have been described herein. The control system 6 is also configured to receive information from the other metering devices described herein. The control system 6 is also configured to issue instructions to one or more valves described herein as well as to the service supply unit or units 4, and/or the distribution pump 513, and/or the storage and distribution unit 3. Accordingly, the control system 6 includes an input/output module 61. The input/output module 61 may include a sensor/meter interface 61 1 configured to be coupled to one or more of the various sensors and metering devices disclosed herein through a 'wired' communication channel. The sensor/meter interface 61 1 may include a plurality of connectors, each of which is configured to be coupled to an electrical conductor which is also coupled (directly or indirectly) to one or more of the sensors and metering devices. The sensor/meter interface 61 1 may be an input/output interface in some embodiments (i.e. capable of two-way communication) or may be an input-only interface (i.e. capable of one-way communication only). For example, the sensor/meter interface 61 1 may use a communication bus in order to receive information from one or more of the sensors and/or metering devices - which may use a standard communication bus technology such as the KNXBus or MBus.

In some embodiments, the sensor/meter interface 61 1 includes a wireless communication unit 61 1 1 which is configured to communicate wirelessly with one or more of the sensors and/or metering devices. In some embodiments, the sensor/meter interface 61 1 is an optical interface which is coupled by optical fibre or fibres to one or more of the sensors and/or metering devices (this is another example of a wired communication channel which may be a one or two way communication channel).

As will be appreciated, the sensor/meter interface 61 1 may use several different communication techniques (wired or wireless) to receive information from one or more of the sensors and/or metering devices. For example, it may receive information wirelessly from one sensor, and over a communication bus from another sensor, etc. In some example embodiments, the sensor/meter 61 1 may communicate with one sensor over a communication channel which comprises both wired and wireless portions in series. The input/output module 61 is also configured to communicate with other parts of the system 100. For example, the input/output module 61 may be configured to communicate with the service supply unit or units 4, and/or the distribution pump 513, and/or the storage and distribution unit 3. This communication may include one or more instructions which are output by the control system 6 to these parts of the system 100. Therefore, the input/output module 61 may also include an instruction interface 612.

The instruction interface 612 may, in some embodiments, be the same as the sensor/meter interface 61 1 and/or may be of the same type. If the instruction interface 612 is a one-way interface, however, the direction of communication is from the control system 6 to the other parts of the system 100 (rather than vice versa, as may be the case for the sensor/meter interface 61 1 ). In some embodiments, however, the instruction interface 612 is a two-way interface which may be over a wired and/or wireless communication channel. The input/output module 61 may further include an ancillary communication interface 613. The ancillary communication interface 613 is configured to receive and/or send information to one or more ancillary services 12 - as will become apparent. .

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The control system 6 further includes a control strategy module 62 which is configured to receive information from the input/output module 61 relevant to the operation of at least part of the rest of the system 100, and to output one or more instructions to at least part of the rest of the system 100 to control an aspect of the operation of the system 100 in accordance with a control strategy.

In some embodiments, the control strategy module 62 is configured to use the information received from one or more temperature and/or pressure sensors, and/or one or more metering devices, of the system 100 in feedback loops as part of the control strategy and to ensure the correct operation of the system 100.

The control system 6 includes a computer readable medium 614 on which is stored configuration and additional information for the system 100. This configuration and additional information may include one or more of:

- the type and operating characteristics of the one or more service supply units

4 of the system 100,

- the type and operating characteristics of the distribution and storage unit 3,

- the type and operating characteristics of the distribution pump 513,

- the type and occupancy characteristics of the building unit or units 2 which the system 100 serves,

- details of the layout of the building unit or units 2 which the system 100 serves,

- details of the geographical location of the building unit or units 2 which the system 100 serves,

- information about the climate in that geographical location,

- details of the orientation of the building unit or units 2 which the system 100 serves,

- historic information regarding service usage characteristics for one or more building units 2,

- one or more economic constraints,

- one or more environmental constraints, and

- information about public holidays. In some embodiments, the control strategy module 62 may be configured to access the configuration and additional information stored on the computer readable medium 614 and to use at least a part of that information in defining the control strategy. The control strategy module 62 may further receive (and/or request) ancillary information from one or more ancillary service 12 via the ancillary communication interface 613. This ancillary information may also be used by the control strategy module 62 in defining the control strategy. In some embodiments, the control system 6 seeks to predict the likely level of demand for the services which the system 100 is configured to serve - e.g. hot water and/or heating.

In anticipation of a high demand for hot water and/or heating, the control system 6 may issue instructions which cause one or more of the service supply units 4 to heat liquid for storage in the storage and distribution unit 3 (e.g. in a tank 31 (which may be a stratification vessel 31 a)).

In anticipation of low demand for hot water and/or heating, the control system 6 may issue instructions which cause one or more of the service supply units 4 to shut down and to stop heating liquid for storage.

Similarly, the control system 6 may issue instructions to control the operation of the distribution pump 513 to increase the speed of the pump 513 for anticipated periods of high demand and to decrease the speed of the pump 513 for anticipated periods of low demand.

The control system 6 may also be configured to issue instructions which cause the transfer of liquid between tanks 31 of the storage and distribution unit 3 in order to prepare for periods of high demand or low demand.

The control system 6 seeks, therefore, to control aspects of the operation of the system 100 to anticipate demands on the system 100 and to operate the system 100 to meet the demands in an efficient manner. The control system 6, therefore, seeks to reduce the oversupply issues seen in some earlier centralised systems.

The control system 6 may, for example, use information about the type and operating characteristics of the one or more service supply units 4 of the system 100, to determine which service supply unit 4 of a plurality of service supply units 4 would be the most efficient to heat liquid for use in relation to a particular demand or anticipated demand. For example, in certain environmental conditions (such as extreme cold) certain types of service supply unit 4 may not function or may not function efficiently (e.g. a gas absorption heat pump); therefore, the control system 6 may issue instructions to cause the heating of liquid using a different service supply unit 4. In some instances, the control system 6 may use one service supply unit 4 to preheat liquid which is then used as the return liquid for another service supply unit 4 in order to achieve more efficient operation.

One such example, may be the use of a service supply unit 4 including a gas absorption heat pump as a heating mechanism 43 to pre-heat liquid which is delivered to the second tank 31 (as described in relation to some embodiments above) and then passed to the first tank 31 (as described in relation to some embodiment above), the liquid in the second tank 31 then being delivered to the one or more boilers for further heating of the liquid. The pre-heating of liquid in this manner may, for example, enable a condensing boiler to operate in its condensing mode of operation for a longer period of time. The control system 6 may use information about the type and operating characteristics of the distribution and storage unit 3 to determine if a tank 31 (such as a stratification vessel 31 a) may be used in a particular manner to improve the overall efficiency of the system 100. The control system 6 may use information about the type and operating characteristics of the distribution pump 513 to determine the optimal operating speed of the distribution pump 513 and to issue instructions with a view to maintaining more energy efficient operation of the distribution pump 513 for longer. This may include operating the distribution pump 513 within its range of most efficient operating speeds for longer. It may, for example, prove more energy efficient to operate the distribution pump 513 at a speed which is faster than is necessary for the given demand and to use other parts of the system 100 to relieve any excess liquid pressure. In embodiments, the control system 6 is configured to operate the distribution pump 513 based on a control algorithm which seeks to minimise the temperature of the liquid which is returned via the main heating return conduit 8. In other words, the control system 6 may be configured to operate the distribution pump 513 such that the heat energy supplied through the main heating output conduit 7 is substantially used and/or lost in the distribution system 5. Therefore, the temperature of the liquid which is returned via the main heating return conduit 8 may be substantially equal to the ambient temperature in some embodiments - or this may be the aim of the control system 6. The control system 6 may control the operation of the distribution pump 513 and/or the service supply unit or units 4 to achieve the desired minimum return temperature for the liquid. In some embodiments, the temperature of the heated liquid delivered to the main heating output conduit 7 is substantially constant but the pressure of the liquid is varied - using the distribution pump 513. In some embodiments, the temperature of the heated liquid varies within a range and the pressure of the liquid is varied - using the distribution pump 513.

In embodiments in which the distribution system 5 includes the temperature and/or pressure and/or flow sensor 53, the control system 6 may use feedback from the temperature and/or pressure and/or flow sensor 53. In such embodiments, the control system 6 may use a control algorithm which seeks to minimise the temperature of the liquid sensed by the temperature and/or pressure and/or flow sensor 53 - again, by controlling one or more aspects of the operation of the storage distribution unit 3 and/or distribution system 5, such as by controlling the operation of the or each service supply unit 4 and/or the distribution pump 513.

In embodiments, it will be appreciated that an increase in demand for hot water or heating will need to be satisfied by the provision of more heat energy via the distribution system 5. This may be achieved by increasing the temperature of the liquid (using the or each service supply unit 4) and/or by increasing the flow rate (and hence the pressure) of the liquid (using the distribution pump 513). A short period of increase in _{c o}

o

demand may be more efficiently met with an increase in the flow rate of the liquid as this can be more quickly achieved and more quickly returned to a lower flow rate after the short period of demand. A long period of increase in demand may equally be met using a higher flow rate but could also be achieved (either in combination or alone) with an increase in the temperature of the liquid. If a long period of increase in demand is anticipated then addition liquid can be heated and stored in advance. The flow rate can also be varied in the event of an anticipated long periods of increase in demand in order to meet short term peaks in demand and/or to reduce the temperature to which the liquid must be heated in order to meet demand.

A low temperature of liquid in the main heating return conduit 8 helps to reduce system losses in the main heating return conduit 8 - which are conventionally very high.

With the use of the distribution pump 513 to control flow rate in order to meet demand for heated liquid, the liquid does not necessarily need to be heated as much as would otherwise be necessary - e.g. in a system in which demand is conventionally met by increasing the temperature of the liquid. This increases the ability to use the second service supply unit 42 to meet demand. Embodiments may also allow the use of smaller gauge conduits (i.e. pipes) for the main heating output conduit 7 and the main heating return conduit 8.

In embodiments, the control system 6 may use a control algorithm which will react to an increase in demand for heated liquid by, initially, increasing the flow rate of heated liquid delivered to the main heating output conduit 7. The algorithm may then delay controlling the or each service supply unit 4 to provide more heated liquid (and/or hotter heated liquid) for a predetermined period - which may vary depending on one or more other factors (such as the time of day) which may be used to predict possible demand. After the predetermined period, the control algorithm may then assess whether or not the demand (and, in some embodiments, also anticipated future demand) has been met. If the demand (and anticipated future demand, in relevant embodiments) has not been met, may not be met in the future, or the risk of demand not being met is unacceptable, then the control algorithm may be configured to control the or each service supply unit 4 to generate more (and/or hotter) heated liquid. The control system 6 may use information about the type and occupancy characteristics of the building unit or units 2 which the system 100 serves to determine likely schedules for demand for services (such as hot water, and heating). For example, retired occupants of building units 2 which are apartments will demand hot water and heating at different times of day compared to occupants of the same building units 2 who are of employed. Similarly, building units 2 which are offices will have different typical demands to building units 2 which are one bedroom apartments, which will have different typical demands to building units 2 which are three or four bedroom apartments. By using information of this type it may be possible for the control system 6 to anticipate likely demand for services, the level and likely timing of that demand.

The control system 6 may use details of the layout of the building unit or units 2 which the system 100 serves to determine whether there is likely to be high demand from some of the building units 2 or from part of a particular building unit 2. For example, some building units 2 or parts of building units 2 may be exposed to strong sunlight or strong winds at certain times of the day or year. The control system 6 may use this information to predict changes in demand for services and may operate the system 100 accordingly.

The control system 6 may use information about the geographical location of the building unit or units 2 which the system 100 serves to determine demand characteristics which are dependent on geographical location. For example, sunrise and sunset times at the geographical location may influence demand for services or whether or not a particular service supply unit 4 can be operated (e.g. solar panels).

The control system 6 may use information about the climate in that geographical location to determine likely demand and use restrictions for particular types of service supply unit 4 - which may also be based on the time of year.

The control system 6 may use details of the orientation of the of the building unit or units 2 which the system 100 serves to aid in determining which parts of the building unit or units 2 may be exposed to particular environmental conditions. _ _

60

The control system 6 may use historic information regarding service usage characteristics for one or more building units 2 to predict future demands - historic demands often being representative of future demands. The control system 6 may use information about one or more economic constraints to determine whether demand is best fulfilled by one service supply unit 4 or another. For example, the control system 6 may determine that a particular demand can be met using a service supply unit 4 that is less expensive to operate than another. The control system 6 may use information about one or more environmental constraints to determine whether demand is best fulfilled by one service supply unit 4 or another. For example, the control system 6 may have an emissions target and, as a result of the emissions target, may favour one form of service supply unit 4 over another.

The control system 6 may use information about public holidays to determine likely changes in demand due to altered patterns - for example, for building units 2 comprising apartments, a public holiday may mean a later than normal demand for hot water in the morning and for building units 2 comprising offices, a public holiday may mean a very low demand for all services for the whole day.

The control system 6 may receive additional information from one or more ancillary services 12 to predict demand for services. For example, the information from the one or more ancillary services 12 may include weather forecast information. Weather forecast information may allow the control system 6 to anticipate short term changes to environmental conditions which are not available from more general climate information. Weather forecast information (and climate information) may include temperature, rainfall, snowfall, hail, solar gain, wind chill, and like.

Other ancillary services 12 may include a news service which provides information regarding unexpected public holidays - e.g. a day of national mourning. Such unexpected public holidays may change the expected service demand to be more similar to a weekend or normal public holiday and the control system 6, on receiving this information, may be able to operate the system 100 to anticipate the demand appropriately. A public holiday is an example of an indicator of a likely atypical demand. Other indicators may also be used. The control system 6 may, in embodiments, be configured to record service demand information for future use by the control system 6. Similarly, the control system 6 may be configured to record information about the operation of components of the system 100 for future use by the control system 6 - for example, this information may be used to provide more accurate predictions regarding the operation of the system 100 - such as how long a service supply unit 4 takes to heat liquid to a particular temperature or how much fuel the service supply unit 4 consumes. As will be appreciated, the actual usage information may differ from information provided by the manufacturers and so real-life information may allow for more accurate and efficient operation in the future. In some embodiments, the control system 6 is configured to use only the first service supply unit 41 to heat liquid for delivery to the storage and distribution unit 3 during periods in which the second service supply unit 42 is inoperable (e.g. due to environmental conditions). The control system 6 may be configured to use both the first 41 and second 42 service supply units when both units 41 ,42 are operable and there is a high demand. The control system 6 may be configured to use only the second service supply unit 42 during periods of low demand (when it is operable). The control system 6 is configured to determine the extent to which heated liquid stored in the storage and distribution unit 3 (e.g. in the stratification vessel 31 a or other tank 31 ) can meet the demand and to factor this into deciding whether or not to heat additional liquid using one or both of the first and second service supply units 41 ,42.

In some embodiments, a prediction program may be provided. The prediction program may be provided as part of the control system 6 or may be independent of the control system 6 or, indeed, independent of the system 100.

In example embodiments in which the prediction program is provided as part of the system 100, the prediction program may use information about the system 100 to predict the effects of changes to the information used by the control system 6. ^

62

Thus, for example, the predicted cost of operating the system 100 can be determined for a given period based on the predicted operation of the control system 6 in instructing other parts of the system 100. Changes in any of the information detailed above - such as information about the type and operating characteristics of the one or more service supply units 4 of the system 100 could be altered to provide predictions of the effects of upgrading or changing a service supply unit 4 or the addition of a new service supply unit 4. The same is true in relation to alterations of any of the other components of the system 100. Similarly, the effects of changes to the type and occupancy characteristics of the building unit or units 2 which the system 100 serves can be predicted. This may allow a management-user, for example, to predict the effects of changing occupancy characteristics for the building unit or units 2. The prediction program may be made available to a management-user to allow the management-user to predict the effects of changes in the operation and management of the building unit or units 2.

The prediction program may, therefore, provide a user interface on a display screen which allows the user to interact with a model of the operation of the system 100 and to see the effects of changes to the information used by the control system 6 or to the components of the system 100.

The effects may be financial or environmental, for example. The effects may be visualised by the prediction program as charts or graphs, for example.

In effect, therefore, the prediction program provides a simulation of the operation of the system 100 which can be modified. In some embodiments, the control system 6 is provided with a remote monitoring interface 615 which is configured to allow the control system 6 to communicate with a remote monitoring system 13. The control system 6 may be configured to transmit information to the remote monitoring system 13 regarding the demand for services and/or the operation of the components of the system 100. This transmitted information 63

may include any of the other information which the control system 6 is configured to use as part of its operation. The remote monitoring system 13 is configured to receive the information from the control system 6 and to use this information to generate models and additional information for use by that and other control systems 6 - to improve their ability to predict demand and operate the system 100 more efficiently.

In some embodiments, the remote monitoring system 13 is communicatively coupled to a plurality of control systems 6 and is configured to receive and record information from each for use in improving the operation of those control systems 6 and other control systems 6.

In some embodiments, the control system 6 is configured to receive information from the one or more metering devices 522 of the heat transfer unit 52 via the sensor/meter interface 61 1 . The control system 6 may be configured to forward the information received from the one or more metering devices 522 to a remote billing system 14 (see figures 8 and 10) via a remote billing interface 616 of the control system 6. The information may include one or more identifiers for the heat transfer unit 52 from information originated along with the information regarding usage obtained from the one or more metering devices 522.

The remote billing system 14 may be configured to match the one or more identifiers for the heat transfer unit 52 with end-user information (including a name and address) stored in the remote billing system 14. The remote billing system 14 may be configured to generate one or more bills for the usage of the services provided by the system 100 accordingly. In some embodiments, the remote billing system is configured to calculate the cost of the usage of the or each service for inclusion in the generated bill. In some embodiments, the or each service which is provided by the system 100 may be billed separately and the cost for heating water per unit of volume of water heated may be different from the cost of providing heating per unit of volume of water heated.

In some embodiments, the or each heat transfer unit 52 is configured to transfer the information directly to the remote billing system 14 rather than via the control system 6. _ .

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Accordingly, the heat transfer unit 52 may be provided with the remote billing interface 616 instead of the control system 6 being provided with this interface 616.

In relation to the one or more heat transfer units 52 of some embodiments, the clock 524 was described as potentially being remote from the or each heat exchanger 521 and that it may be part of the controller which forms part of the control equipment 16 associated with the heat transfer unit 52. That controller may, as discussed, include a user interface and a memory. The user interface may be configured to display to the user information about the usage of the service or services provided by the system 100 through the associated heat transfer unit 52. For example, the information may include the volume of hot water generated and/or the volume of water heated. In some embodiments, the remote billing system 14 is communicatively coupled to that controller such that the user interface is also configured to display to the user information about the cost of the services provided. The controller and/or user interface may be provided as part of an separate remote device such as a computer, tablet, mobile (i.e. cellular) telephone, laptop, watch, or the like.

In some embodiments, the communicative coupling between that controller and the remote billing system 14 is via the control system 6. The control system 6 may provide additional information for display to the user, such as predicted usage - including the cost of predicted future usage.

Parts of the system 100 may include one or more tamper prevention mechanisms and sub-systems 15. For example, a respective first tamper switch 151 may be provided in relation to a housing of at least the one or more heat transfer units 51 . The first tamper switch 151 may be configured to actuate on removal or movement of the housing of the heat transfer unit 51 . Actuation of the first tamper switch 151 be activate the shut-off valve 527 of the heat transfer unit 51 to prevent further operation of the unit 51 . The first tamper switch 151 may be reset be an authorised user (such as a management- user) and this may be done locally in some embodiments (i.e. by direct manipulation of the shut-off valve 527) or remotely (e.g. via the control system 6). The first tamper switch 151 may be communicatively coupled to the control system 6 such that the control system 6 is aware of the actuation and/or that that the shut-off valve 527 has _ ._

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been activated. The control system 6 may, as a result, issue an alert to a management- user (e.g. an automated email or the like), for example.

A second tamper switch 152 may be associated with the modularly constructed plant room 200 (see figure 1 1 ) such that the opening of a door of the plant room 200 to gain unauthorised access may actuate the second tamper switch 152. Actuation of the second tamper switch 152 may trigger an alarm which may be an audible and/or visual alarm in the vicinity of the plant room 200. Unauthorised access may be determined if a key is not used in a lock of the door, or a signal is not received by the control system 6 warning of intended authorised access to the plant room 200 (an authorised user being able to interact with the control system 6 remotely to inform the control system 6 of intended access). The second tamper switch 152 may, therefore, be communicatively coupled to the control system 6. A tamper detection sub-system 153 may be associated with the or each heat transfer units 52 respectively (each heat transfer unit 52 may be associated with its own tamper detection sub-system 153). The tamper detection sub-system 153 may be configured to compare the volume of water which has been heated by one or more of the or each heat exchangers 521 (as measured by one or more of the metering devices 522) with an expected change in temperature. The expected change in temperature may be an expected change in temperature as measured within the associated building unit 2 (e.g. using the thermostat 523) or may be the expected temperature change of the liquid in a part of the system 100 (e.g. in the distribution output or return conduit 51 1 ,512) in the region of the heat transfer unit 52 (e.g. measured by one or more temperature sensors 51 13,5124), or may be a temperature change within of the water or liquid within the heat transfer unit 52 (which may be measured by one or more temperature sensors of the heat transfer unit 52 and configured to measure the temperature of the water and/or liquid downstream of the or each heat exchanger 521 ). In some embodiments, if the volume of water which has been heated does not result in a predetermined temperature change (e.g. within a predetermined temperature range), then the tamper detection sub-system 153 determines that the heat transfer unit 52 may have been tampered with and the shut-off valve 527 is activated to terminate use of the heat transfer unit 52 (as described above). In any event, on detection of suspected ^

66

tampering, the tamper detection sub-system is configured to issue an alert and this alert may cause, for example, the activation of the shut-off valve 527 or the sounding of an alarm. The comparison may be performed by a part of the tamper detection sub-system 153 which is part of the heat transfer unit 52 or the comparison may be performed by a part of the tamper detection sub-system 153 which is part of the control system 6 (and which is configured to receive the required information for the comparison from the heat transfer unit 52).

In some embodiments, the heat transfer unit 52 and/or the control system 6 includes a leak detection sub-system 17 which is configured to compare one or more measured pressures within the heat transfer unit 52 or system 100 to determine if there is likely to be a leak in a building unit 2. If a likely leak is detected, then the leak detection sub- system 17 may activate the shut-off valve 527 and may also be configured to activate one or more of the isolation 526 valves for the heat transfer unit 52 with a view to reducing wasted energy and/or water.

References have been made herein to "liquid" and "heated liquid". Such references are to be construed as encompassing that liquid being water or water-based. For example, the liquid may be a solution and/or may contain one or more additives. Such a solution or additives may make that liquid or heated liquid unsuitable for human consumption. For example an additive may inhibit the formation of ice within the liquid. In some embodiments, a second heating system is provided to provide a small amount of heat to the various components of the system 100 to inhibit or substantially prevent the formation of ice.

Any sensors or meters disclosed herein may be provided with a display to display the measurements the sensor and/or meter has made.

As will be appreciated, in the case of condensing boilers used as heating mechanisms 43, each boiler would be in liquid communication with a drain to drain away the condensed water produced through operation. In addition, each boiler would be in fluid __,

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communication with one or more flues to ensure the exhaust gases are exhausted to the atmosphere safely.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.