GB2514187A

GB2514187A - Heating installation

Info

Publication number: GB2514187A
Application number: GB1308962.8A
Authority: GB
Inventors: Jan Oesterholm Hansen
Original assignee: V United Kingdom Ltd SA
Current assignee: V United Kingdom Ltd SA
Priority date: 2013-05-17
Filing date: 2013-05-17
Publication date: 2014-11-19
Anticipated expiration: 2033-05-17
Also published as: GB2514187B; GB201308962D0

Abstract

Disclosed is a space heating installation comprises an inlet source pipe 6 for hot water, an outlet source pipe 7 and a station housing 30. It also provides a first electrically actuated valve 107A controlling the flow of water through a first heating circuit and a second electrically actuated valve 107B controlling the flow of water through a second heating circuit. The first and second valves are provided in a common valve housing 103 connected to the local heating supply pipe 16 via an elbow connection 105 such that the local heating supply pipe 16 extends in a direction away from the station housing but the longitudinal flow path in the valve housing extends alongside a border of the station housing 30.

Description

Heating Installation This invention relates to a heating installation for supplying space heating via more than one heating circuit from a common source of hot water. The invention also relates to a building including such an installation and to a method of heating employing such a heating installation.

The invention is particularly, but not exclusively, concerned with heating two (or more) zones of a domestic dwelling with separate heating circuits.

In a conventional radiator or underfloor heating installation for a domestic dwelling hot water is passed around a circuit and a thermostat controls a valve which in turn controls the flow of water in the circuit. More recently, it has been known to employ two heating circuits which are controlled by respective thermostats and valves.

That enables one heating circuit to be employed to heat the living area of a dwelling and another circuit to be employed to heat the bedroom area. By providing two separate circuits that are separately controlled by respective valves, it becomes possible to provide a heating regime tailored more specifically to the requirements of the occupants of the dwelling.

Often, a domestic heating installation for a dwelling employs hot water generated by a boiler or other heat source dedicated to that particular dwelling, but it is also known for a number of dwellings to employ a common source of hot water. That may be the case in an apartment block or a district heating scheme. Tn such a case it may be especially advantageous to employ in each individual dwelling a device known as a Flatstation as a heat interface unit that employs the heat from the common source of hot water to provide, via one or more appropriate heat exchange units, hot water for heating and for a hot water supply to be used in the dwelling. Such a Flatstation has to be accommodated in each dwelling and is therefore desirably as compact as possible. Nonetheless the Flatstation must include supply and return pipes to the communal heating source, supply and return pipes for space heating and, if a hot water supply is also required, inlet and outlet pipes for that hot water supply. That makes it challenging to provide a compact Flatstaticn.

It is an object of the invention to provide an improved heating installation for supplying space heating.

According to the invention there is provided a heating installation comprising: an inlet source pipe for connection to a supply pipe of a source of hot water; an cutlet source pipe for returning the water that has entered the installation through the inlet source pipe; a local heating supply pipe for supplying water for space heating; a local heating return pipe for returning water used for space heating; a station housing; wherein the inlet source pipe, the outlet source pipe, the local heating supply pipe and the local heating return pipe are disposed partly within the station housing, project outwardly from the station housing and terminate in respective connectors adjacent to the station housing; a first heating circuit ccnnected to receive hot water from the local heating supply pipe, pass the water through one or more heating appliances and return the water to the local heating return pipe; a first electrically actuated valve for controlling the flow of water through the first heating circuit; a second heating circuit connected to receive hot water from the supply pipe, pass the water through one or more heating appliances and return the water to the return pipe; and a second electrically actuated valve controlling the flow of water through the second heating circuit; wherein the first and second valves are provided in a common valve housing in which is defined a longitudinal flow path in communication with a first transverse flow path defining a flow path of the first heating circuit and associated with the first valve and a second transverse flow path defining a flow path of the second heating circuit and associated with the second valve, the second transverse flowpath being longitudinally spaced from the first transverse flowpath and extending generally parallel thereto; and wherein the common valve housing is connected to the local heating supply pipe via an elbow connection such that the local heating supply pipe extends in a direction away from the station housing but the longitudinal flow path in the valve housing extends alongside a border of the station housing.

By prcviding the first and second valves, which control separate heating circuits which may heat spaces that are well apart from one another, in a common valve housing, it becomes possible to provide an especially compact and economical installation. Furthermore the configuration of the common valve housing and its positicning alongside a border of the station housing enables a compact arrangement to be provided which can more easily be accommodated in a dwelling. That may be of particular advantage when the dwelling is an apartment or other compact dwelling. Whilst the installation may be a wireless installation, more often there will be wiring and the present invention can also reduce the wiring required.

Whilst reference is made to first and second heating circuits, it should be understood that there may also be one or more further heating circuits that are connected to receive hot water from the supply pipe; any such further circuit may have an associated valve which may also be provided in the common housing.

It should also be understood that whilst the heating medium is referred to as "water" and that would be the usual medium employed, the "water" may well have an additive such as glycol added to it and it is within the scope of the invention for some other liquid to be passed through the installation as the heating medium.

Preferably the heating installation further includes an energy meter for measuring one or more variables relating to the water returning through the outlet souroe pipe. The variables may be the amount of water returned, which may for example be measured by continuous monitoring of the flow through the inlet source pipe or the outlet source pipe, and/or the temperature of the water returning through the outlet source pipe. The energy meter preferably also monitors the temperature of the water entering through the inlet source pipe and is therefore able to measure the temperature drop of the water as it passes through the installation. !I!he energy meter preferably further includes a calculation unit for calculating the energy consumed from the flow-rate and temperature information. 2111 or part of the energy meter may be accommodated in the station housing. For example the calculation unit may be located outside the station housing with the temperature monitors and the flow-rate mon±tor inside the station housing.

The first and second transverse flowpaths in the common valve housing preferably extend in a direction away from the station housing. Preferably the first and second transverse flowpaths in the common valve housing extend in a direction substantially coplanar with and, more preferably, substantially parallel to, the direction in which the local heating supply pipe prcjects frcm the station housing.

The common valve housing may define a manifold and may be a casting.

The installation preferably includes a further housing in which is defined a longitudinal flow path in communication with a first transverse flow path defining a flow path of the first heating circuit and a second transverse flow path defining a flow path of the second heating circuit, the second transverse flowpath being longitudinally spaced from the first transverse flowpath and extending generally parallel thereto; and wherein the further housing is connected to the local heating return pipe via an elbow connection such that the local heating return pipe extends in a direction away from the station housing but the longitudinal flow path in the further housing extends alongside a border of the station housing. As in the case of the common valve housing, this configuration of the further housing and its positioning alongside a border of the station housing enables a compact arrangement to be provided which can more easily be accommodated in a dwelling. The first and second transverse flowpaths in the further housing preferably extend in a direction away from the station housing.

Preferably the first and second transverse flowpaths in the further housing extend in a direction substantially copThnar with and, more preferably, substantially parallel to, the direction in which the local heating return pipe projects from the station housing. Preferably, the longitudinal flow path in the common valve housing and the longitudinal flowpath in the further housing extend alongside the same border of the station housing.

Preferably, the common valve housing and the further housing are disposed in end-to-end relationship to one another. In a preferred configuration the local heating supply pipe and the local heating return pipe extend from the station housing adjacent to one another, the common valve housing extends from the local heating supply pipe in a first direction and the further housing extends from the return supply pipe in a second direction opposite to the first direction. The various features described above in this paragraph contribute to enabling a particularly compact arrangement to be provided.

The further housing may define a manifold and may be a casting.

The first and second valves are preferably electrically operated. Electrical operation facilitates connection of the valves to a control unit.

The housing is preferably part of a single unit that also comprises a control box. That again facilitates the design of a compact thermally actuated valve arrangement for two heating circuits. In the case where the first and second valves are electrically operated, the control box is preferably an electrical control box. Electrical conductors preferably extend from the first and second valves into the control box. The electrical connections between the first and second valves and the control box are preferably made during manufacture of the unit; an installer does not then have to make those connections. A first thermostat may be provided for actuating the first valve according to a temperature sensed by the first thermostat. Similarly, a second thermostat may be provided for actuating the second valve according to a temperature sensed by the second thermostat. Any suitable positions may be chosen for the first and second thermostats. In a domestic dwelling they may advantageously be arranged for sensing room temperature in respective rooms. For example the first thermostat may be placed in a living area and the second thermostat may be placed in a bedroom area.

The one or more appliances may include a radiator. In addition to, or in place of, a radiator there may be a towel rail and/or underfloor heating appliance.

The radiator or other appliance may itself be thermostatically controlled.

The hot water supplied, in use, to space heating appliances may be arranged to be water received from the inlet source pipe; in such a direct heating arrangement the local heating supply pipe may be connected to the inlet source pipe to receive water therefrom. An alternative arrangement, which is described below with reference to the drawings, is an indirect heating arrangement in which the water supplied, in use, to space heating appliances is separate from the water received from the inlet source pipe; in that case a space-heating heat exchanger may be provided in the station housing for reoeiving hot water from the inlet source pipe and returning it to the outlet source pipe after receiving heat and the local heating supply pipe may be arranged to supply water heated by the space-heating heat exchanger, the local heating return pipe being arranged to return water used for space heating to the space-heating heat exchanger.

In either the direct or indirect heating arrangement described above, the heating installation may include: a hot-water heat exchanger in the station housing for receiving hot water from the inlet source pipe and returning it to the outlet source pipe after receiving heat; a local water supply pipe for supplying water to the hot-water heat exchanger for heating therein; and a local hot water supply pipe for supplying water heated in the hot-water heat exchanger for a hot water supply; wherein the local water supply pipe and the local hot water supply pipe project outwardly from the station housing and terminate in respective connectors adjacent to the housing.

In that way a hot water supply can also be provided by the installation, in addition to space heating.

The present invention further provides a dwelling comprising a heating installation as defined above.

The first heating circuit may, for example, be arranged to provide heating for a living area and the second heating circuit may, for example, be arranged to provide heating for a bedroom.

-10 -As will be understood, an installation aooording to the invention will typically be connected, together with several others, to a souroe of hot water. The hot water source may be generated in a wide variety of ways and may even be naturally generated. Accordingly, the present invention further provides a district heating or central plant system comprising means for generating a source of hot water and a multiplicity of heating installations, each as defined above, connected to the source of hot water.

The present invention still further provides a method of heating a plurality of spaces, using a heating installation as defined above.

Certain features of the invention have been described above only with reference to the apparatus of the invention. It should be understood that a feature described in respect of the apparatus may be represented also in a feature of the method.

By way of example, a heating system for supplying space heating and hot water to a user in a domestic dwelling will now be described with reference to the accompanying schematic drawings, of which: Fig. 1 is a block diagram of the heating system; Fig. 2 is a view of a heating installation forming part of the system of Fig. 1; and Fig. 3 is an isometric view of a unit employed in the installation of Fig.2.

Referring first to Fig.1, there is shown a heating system for supplying hot water and space heating to a user, -11 -the system being one of, typically, 10 to 100 similar systems that are all connected to a common heat source in a distriot heating system, with eaoh system serving a respective dwelling which might be, for example, a two bedroom apartment.

The heating system shown in the example of Fig. 1 generally comprises five physical parts: Flatstation -shown in Fig.1 and bounded approximately by the dotted outline referenced 1.

Space heating valve control assembly -shown in Fig. 1 and bounded approximately by the dotted outline referenced 2.

Space heating return manifold -shown in Fig. 1 and bounded approximately by the dotted outline referenced 3.

Radiator module -shown in Fig. 1 and bounded approximately by the dotted outline referenced 4.

Underfloor heating module -shown in Fig. 1 and bounded approximately by the dotted outline referenced 5.

The Flatstation 1 may be of a kind known per se, for example the Flatstation known as a 7 Series Flatstation and sold by us. The Flatstation 1 is connected to the common hot water source via an inlet source pipe 6 connected in use to a supply pipe (not shown) of the source and an outlet source pipe 7 connected in use to a return pipe (not shown) of the source.

A hot-water heat exchanger 8 is connected on one side via a pipe 9 to receive hot water from the inlet source -12 -pipe 6 and via a pipe 10 to return water to the outlet source pipe 7.

A space-heating heat exchanger 12 is connected on cne side to the inlet source pipe 6 and to the outlet source pipe 7.

Thus it can be seen that the heat exchangers 8 and 12 are connected in parallel to the inlet source pipe 6 and the outlet source pipe 7.

The hot-water heat exchanger 8 serves to generate hot water for use in the dwelling. A cold water supply, which may be a mains supply, is connected to a water supply iulet pipe 13 leading to the other side of the space-heating heat exchanger and communicating with conduits in the heat exchanger which in turn lead to an outlet connected to a heated water pipe 14 providing a supply of domestic hot water.

The space-heating heat exchanger 12 serves to heat water in a substantially closed circulation path for space heating. A heating inlet pipe 15 is connected to feed water into the other side of the heat exchanger 12 and through conduits in the heat exchanger, the heated water leaving the other side of the heat exchanger through a heating outlet pipe 16.

A pump 19 is provided in the heating inlet pipe 15 for pumping water around the substantially closed circulation path already referred to.

A thermostatic valve 20 is provided on the outlet pipe leading from the hot water heat exchanger 8 to the -13 -cutlet source pipe 7. Similarly, a thermostatic valve 21 is provided on the cutlet source pipe 7 adjacent to the space-heating heat exchanger 12. Those thermostatic valves 20, 21 can be used to regulate the flow of hot water from the source through the twc heat exchangers according to demand.

An energy meter 22 is provided in the outlet source pipe 7 dcwnstream of the junction with the pipe 10, fcr continuously measuring the flow rate of water returned to (and also therefore supplied by) the hot water source and the temperature of the water returned to the source. The meter 22 also includes a temperature sensor (not shown) for monitoring the temperature of the water supplied through the inlet source pipe 6 sc that the drcp in temperature of the water as it passes through the heating installaticn can be measured and the energy consumption can be calculated in a calculation unit forming a part of the meter 22 by combining the continuous measurement of the flow rate and the temperature difference measurement. Also shown in Fig. 1 are ball valves 23 which can be manually actuated to isolate various parts of the system and an electrically operated on/off valve 24. Appropriate controls are also provided for controlling the thermostatic valves 20 and 21, and the pump 19 and the on/off valves 24 are connected to a control unit 25.

In operation, with the ball valves 23 open, hot water flows into the installation along the inlet source pipe 6.

Some of that water flows along pipe 9, through the heat -14 -exchanger 8 and along pipe 10 to the outlet source pipe 7 where it flows back out of the system. The rest of the water entering along the inlet source pipe 6 flows through the heat exchanger 12 and back along the outlet source pipe 7. The on/off valve 24, downstream of the heat exchanger 12, is able to shut off the flow through the heat exchanger 12 when reguired to control the heating. As will be understood cold water enters the heat exchanger 8 along the pipe 13 and, after being heated in the heat exchanger, leaves by the pipe 14 from which it can be fed to hot water outlet taps. Similarly water in the space heating circuit enters the heat exchanger 12 along the pipe 15 and, after being heated, leaves the heat exchanger along the pipe 16.

!I!he pump 19 maintains the flow of the water around the circuit through the heat exchanger 12.

As will be understood the Flatstation 1 described above is of a design that is known per se.

Referring now also to Fig. 2, it can be seen the Flatstation 1 has a station housing 30 within which are contained most of the components of the Flatstation. Also visIble in Fig. 2 are the inlet and outlet source pipes 6,7, the water supply inlet pipe 13, and the heated water pipe 14 which are shown projecting outwardly from the top of the housing 30 of the Flatstation 1 and the heating inlet pipe 15 and the heating outlet pipe 16 which are shown projecting outwardly from the bottom of the housing of the Flatstation 1.

-15 -The valve control assembly 2 is connected to the heating outlet pipe 16 and the return manifold 3 is connected to the heating inlet pipe 15.

The valve control assembly 2 is also shown in Fig.3 and generally comprises a mounting bar 101 on which an electrical control box 102, and a manifold 103 are mounted.

The manifold 103 has an inlet 104, to which the heating outlet pipe 16 is connected via an elbow joint 105, and cutlets 106P. and 1068 for supplying heated water to respective space heating circuits as will be described below. The inlet 104, downstream of the elbow joint 105 and the outlets 106A and 106B are defined in a common casting defining a main passageway along its length, the passageway being open at one end defining the inlet 104 and having two branch conduits extending perpendicular to the main passageway and defining the outlets 106A and 10GB at which electrically actuated valves 107A and 1073 are mounted. The casting is secured to the mounting bar 101.

The electrically actuated valves 10Th and 1078 have valve members (not visible in Fig.3) which are positioned in the outlets 106A and 1068 and control the flow of water from the inlet 104 to the outlets 106A and 10GB. Each of the valves 107A and 1073 has an associated electrical cable 108k and 1088 containing appropriate conductors and extending from the respective valve to the control box 102.

The cables 108A and 1088 enter the control box 102 through a common watertight connection so that the interior of the control box is protected against water ingress.

-16 -Referring again to Figs. 1 and 2, It can be seen that the return manifold 3 is of broadly similar construction to the valve control assembly 2 but omits valves and therefore does not require any wiring. More partioularly, the return manifold 3 has an outlet 204, to which the heating inlet pipe 15 is connected via an elbow joint 205, and inlets 206k and 206B fcr returning water from respective space heating circuits as will be described below. The outlet 204, upstream of the elbow joint 205 and the inlets 206k and 206B are defined in a common casting defining a main passageway along its length, the passageway being open at one end defining the outlet 204 and having two branch conduits extending perpendicular to the main passageway and defining the inlets 206A and 206B. As shown in Eig.2, the valve control assembly 2 and the return manifold 3 are of similar external shape. The heating inlet pipe 15 and the heating outlet pipe 16 project vertically downwardly adjacent to one another from the housing 30. As a result of the elbow joint 105 the manifold 103 extends alongside the bottom of the housing 30 and as a result of the elbow joint 205 the return manifold 3 extends alongside the bottom of the housing 30 in the opposite direction to the manifold 103 and ooaxial therewith. The outlets 106A and 106B and the inlets 206A and 206B all project vertically downwards from the manifolds and have externally threaded portions for connection to downwardly extending pipes. The housing is of relatively small depth compared to its width and height.

-17 -The outlet 106A and the Inlet 206A are connected to respective ends of a second heating circuit while the outlet 1068 and the inlet 2068 are connected to respective ends of a first heating circuit. In Fig. 1, the first heating circuit is shown as comprising a radiator module 4 and the second heating circuit is shown as comprising an underfloor heating module 5. Each of the modules 4 and 5 will typically feed hot water to a plurality of appliances in the dwelling. Typically one heating circuit will heat a living space and the other heating circuit will heat a bedroom space.

Whilst the arrangement just described is one possible arrangement, it should be understood that other arrangements are equally possible: for example, there could be two radiator modules or two underfloor heating modules.

Whilst in Fig.l, modules are shown with their own associated manifolds, it will be understood that such manifolds may not be present in some applications. For example, there may be radiators connected directly to pipes extending from the outlets bOA, 10GB and the inlets 206A and 2068. Also, the valve control assembly 2 and the return manifold 3 may have more than two outlets/inlets with each cutlet on the valve control assembly having a respective associated electrically actuated control valve.

As shown in Fig. 1, the modules 4 and 5 have their own electrically operated valves each of which is electrically connected to the control unit 25 and the valve control -18 -assembly is also electrically oonnected to the oontrol unit -r7here in the foregoing desoription, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then suoh equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. Tt will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims.

Claims

-19 -Claims: 1. 2& heating installation comprising: an inlet source pipe for oonneotion to a supply pipe of a source of hot water; an outlet source pipe for returning the water that has entered the installation through the inlet source pipe;a local heating supply pipe for supplying water for space heating; a local heating return pipe for returning water used for space heating; a station housing; wherein the inlet source pipe, the outlet source pipe, the local heating supply pipe and the local heating return pipe are disposed partly within the station housing, project outwardly from the station housing and terminate in respective connectors adjacent to the station housing; a first heating circuit connected to receive hot water from the local heating supply pipe, pass the water through one or more heating appliances and return the water to the local heating return pipe; a first electrically actuated valve controlling the flow of water through the first heating circuit; a second heating circuit connected to receive hot water from the supply pipe, pass the water through one or more heating appliances and return the water to the return pipe; and -20 -a second electrically actuated valve controlling the flow of water through the seoond heating circuit; wherein the first and second valves are provided in a common valve housing in which is defined a longitudinal flow path in communication with a first transverse flow path defining a flow path of the first heating circuit and associated with the first valve and a second transverse flow path defining a flow path of the second heating circuit and associated with the second valve, the second transverse flowpath being longitudinally spaced from the first transverse flowpath and extending generally parallel thereto; and wherein the common valve housing is connected to the local heating supply pipe via an elbow connection such that the looal heating supply pipe extends in a direction away from the station housing but the longitudinal flow path in the valve housing extends alongside a border of the station housing.
2. A heating installation according to claim 1, further including an energy meter for measuring one or more varIables relating to the water returning through the outlet source pipe.
3. A heating installation according to olaim 2, in whioh the energy meter is arranged to monitor the flow rate and temperature of water returning through the outlet source pipe.
4. A heating installation according to any preceding claim, in which the first and second transverse flowpaths -21 -in the common valve housing extend in a direction away from the station housing.
5. A heating installation according to any preoeding claim, in which the common valve housing is a casting.
6. A heating installation according to any preoeding claim, including a further housing in which is defined a longitudinal flow path in communication with a first transverse flow path defining a flow path of the first heating circuit and a second transverse flow path defining a flow path of the second heating circuit, the second transverse flowpath being longitudinally spaced from the first transverse flowpath and extending generally parallel thereto; and wherein the further housing is connected to the local heating return pipe via an elbow connection such that the local heating return pipe extends in a direction away from the station housing but the longitudinal flow path in the further housing extends alongside a border of the station housing.
7. A heating installation according to any preceding claim, in which the first and second transverse flowpaths in the further housing extend in a direction away from the station housing.
8. An installation according to claim 7, in which the longitudinal flow path in the common valve housing and the longitudinal flowpath in the further housing extend alongside the same border of the station housing.

-22 -
9. An installation according to claim 8, in which the common valve housing and the further housing are disposed in end-to-end relationship to one another.
10. An installation aocording to claim 9, in which the local heating supply pipe and the local heating return pipe extend from the station housing adjacent to one another, the common valve housing extends from the local heating supply pipe in a first direction and the further housing extends from the return supply pipe in a second direction opposite to the first direction.
11. A heating installation according to any of claims 6 to 10, in which the further housing is & casting.
12. A heating installation according to any preceding claim, in which the first and second valves are electrically operated.
13. A heating installation according to any preceding claim, in which the oommon valve housing is part of a single unit that also comprises a control box.
14. A heating installation according to claim 13 when dependent upon claim 12, in which the control box is an electrical control box and electrical conductors extend from the first and second valves into the control box.
15. A heating installation according to any preceding claim, in which a first thermostat is provided for actuating the first valve according to a temperature sensed by the first thermostat and a second thermostat is provided for actuating the second valve according to a temperature sensed by the second thermostat.

-23 -
16. A heating installation according to any preceding claim, in which the one or more appliances includes a radiator.
17. A heating installation according to claim 16, in which the radiator is itself thermostatically controlled.
18. A heating installation according to any preceding claim, in which the one or more appliances includes an underfloor heating appliance.
19. A heating installation according to claim 18, in which the underiloor heating appliance is itself thermostatically controlled.
20. A heating installation according to any preceding claim, in which a space-heating heat exchanger is provided in the station housing for receiving hot water from the inlet source pipe and returning it to the outlet source pipe after receiving heat and the local heating supply pipe is arranged to supply water heated by the space-heating heat exchanger, the local heating return pipe being arranged to return water used for space heating to the space-heating heat exchanger.
21. A heating installation according to any preceding claim, including: a hot-water heat exchanger in the station housing for receiving hot water from the inlet source pipe and returning it to the outlet source pipe after receiving heat; a local water supply pipe for supplying water to the hot-water heat exchanger for heating therein; and a local hot water supply pipe for supplying water heated in the hot-water heat exchanger for a hot water supply; wherein -24 -the local water supply pipe and the local hot water supply pipe project outwardly from the station housing and terminate in respective ccnnectors adjacent to the housing.
22. A heating installation substantially as herein described with reference to the accompanying drawings.
23. A dwelling comprising a heating installation according to any preceding claim.
24. A dwelling according to claim 23, in which the first heating circuit is arranged to provide heating for a living area and the second heating circuit is arranged to provide heating for a bedroom.
25. A district heating or central plant system comprising means for generating a source of hot water and a multiplicity of installations, each according to any of claims 1 to 22, connected to the source of hot water.
26. A method of heating a plurality of spaces, using a heating installation according to any of claims 1 to 22.