GB2182759A

GB2182759A - Water heating apparatus for a shower

Info

Publication number: GB2182759A
Application number: GB08625673A
Authority: GB
Inventors: Houghton Ainsworth Gledhill
Original assignee: Gledhill Water Storage Ltd
Current assignee: Gledhill Water Storage Ltd
Priority date: 1985-11-07
Filing date: 1986-10-27
Publication date: 1987-05-20
Also published as: GB2182759B; GB8625673D0

Abstract

The hot water for a shower rose 46 is supplied directly from the mains through a heat exchange coil 44 which is in heat exchange relationship with the heated secondary water in a tank 28 used for the supply of hot water to taps 40 and the like. The coil 44 may be located in the tank 28 or in a smaller separate tank hydraulically connected to the main tank 28. The arrangement allows a shower to be used without raising the cold water tank which feeds the hot water tank or using a feed pump for the shower. <IMAGE>

Description

SPECIFICATION Improvements relating to water heating apparatus This invention relates to water heating apparatus, and in particular concerns apparatus for the heating of water to be used in showers, in particular in domestic showers.

In domestic water installations, the hot water for a shower is usually drawn from the same tank as is the water for the domestic water taps, but frequently such hot water tank which is vented to atmosphere, so that it does not present a sufficiently high head to give the desired flow to the shower rose, and it is often necssary therefore to add a feed pump and/or to raise the cold water tank which feeds the hot water tank.

This represents an expensive alteration, and at least in the case of raising the cold water supply tank, in some instances such alteration may not be physically possible.

The present invention is concerned with a simple and effective means for providing an apparatus whereby these disadvantages are obviated or mitigated, and in accordance with the present invention in a general aspect thereof, a water heating apparatus for supply ing hot water to a shower rose is provided which includes heat exchange coil means through which water at, or driven by, mains pressure is supplied and from which the water duly heated by passing through said coil means is delivered to the shower rose, the water for the shower rose receiving heat by heat exchange with a body of hot water within the water apparatus.

Preferably, the body of water from which the mains water for the shower receives its heat comprises the so-called "secondary" hot water of the apparatus, being the hot water which is contained in a hot water tank and is utilised for supplying the normal usage points such as the taps in the associated building, especially a domestic dwelling house.

In a domestic application, the secondary water is heated by the domestic boiler, which also heats the water in a so-called "primary" circuit which is a closed circuit including the heating system of the dwelling in the form usually of a small bore central heating system with domestic radiators.

The secondary hot water is usually stored in a hot water tank, and in one embodiment of the invention the heat exchange coil means comprises a coil contained in said tank. A coil may be provided in the tank when it is manufactured, or it may be inserted therein in the case where an existing installation is modified.

In a particularly preferred arrangement, the heat exchange coil means is located outside the hot water tank but in its own smaller and separate tank which is coupled to the hot water tank by feed and return pipes at the top and bottom thereof. The separate tank may suitably be thermally insulated. The heat exchange coil means is contained in the separate tank, and when a shower is drawn off, the surrounding water in the tank will fall in temperature, and this has the effect of causing a flow by convection of hot water from the main hot water tank into the separate tank for the continued supply of heat to the water for the shower which passes through the heat exchange coil means.

In all cases, the heat exchange coil means is connected to receive water from the mains, and therefore the water will be at mains pressure. There should therefore be no difficulty in supplying the heated shower water to any shower rose regardless of its location in the dwelling as there will be sufficient pressure in the mains water to ensure the supply, and indeed there may be a flow regulator in the line leading from the mains to the heat exchange coil means for throttling the flow of mains water through the coil means, if the flow is too high.

The heating of the shower water by heat exchange coil means and using water at mains supply pressure represents a number of advantages, one of which as indicated above is that the water will reach any shower rose in the dwelling at sufficient pressure, but secondly, because a shower uses relaltively small amounts of hot water there will be no difficulty in heating the mains supply water passing through the heat exchange coil means to a comfortable temperature. In this regard, there is also the advantage that it may not be necessary to mix cold water with the heated mains pressure water which passes through the heat exchange coil means, and it may therefore be possible in some cases to eliminate the normal shower mixing valve.

The heat exchange coil means may take any suitable form, but it will of course be of substantially smaller volume than the body of water in the hot water tank.

Three embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, wherein: Fig. 1 shows a domestic hot water installation with a heat exchange coil means provided according to the invention; and Figures 2 and 3 respectively indicate two other embodiments in similar fashion to the illustration in Fig. 1.

Referring to Fig. 1, the diagram shows a domestic hot water installation circuit comprising a boiler 10 which receives water from feed tank 12 via line 16. The boiler has an overflow 18 and it is coupled to a primary heating circuit 20 comprising a plurality of small bore central heating radiators 22 which are supplied with hot water from the boiler by a pump 24 which pumps the hot water through the radiators and the circulating small bore piping 26. This is a closed circuit insofar as the pumped water is returned to the boiler to be re-heated and again circulated.

The boiler also heats the water in a secondary circuit and in particular the water contained in a hot water tank 28 by circulating hot water from the boiler through piping 30 to a heat exchange coil 32 in the tank 28.

The water in the tank 28 is supplied from the mains via a mains supply pipe 34 and a header tank 36 there being an inlet supply pipe 38 leading from tank 36 to the lower end of tank 28, and an overflow return pipe 39 leading back to the tank 36. Hot water is drawn from the tank through fawcets or other dispensing points 40 via supply pipe 42 connected to the overflow pipe 39.

The arrangement described essentially is the conventional arrangement in a domestic dwelling, and normally the hot water for the shower or the showers in the domestic dwelling is drawn through piping 42. The maximum pressure at the water which can be supplied through pipe 42 is the head of the water in tank 36, and frequently for showers this head is insufficient, because the water invariably has to be lifted to the shower rose on the one hand, and secondly the design of a shower rose providing a plurality of pin-head outlets represents greater resistance to the outflow of water than does the outlet of a conventional fawcet. Accordingly, it frequently happens that it is not possible to discharge sufficient hot water through the shower rose for satisfactory showering.

The traditional means of overcoming this problem has been either to raise the tank 36 to provide a greater head, and this can only be done when space is available, and in any event is expensive, or a small pump is put in the piping 42 between the tank 28 and the shower outlet, which again represents an expense, and the pump of course is always liable to failure.

The present invention provides means for effecting a solution of the above problem in a simple and effective manner requiring neither the lifting of the header tank nor providing a pump, and in the arrangement of Fig. 1, the additional piping indicated in double and hatched lires is provided, and this additional piping comprises heat exchange coil means 44 in the hot water tank 28 so that water passing through the coil means 44 receives heat from the water tank 28. The coil means 44 is connected to the mains supply line 34 by pipe 47 so that the water passed therethrough will be driven by mains pressure and therefore will easily be delivered to and effectively discharged from the shower rose (indicated by numeral 46), because the outlet from the coil means 44 is through piping 48 to the said shower rose 46.The drawing also shows outlet piping 58 branched from pipe 34 to provide a cold water supply to the shower rose 46, but in some instances this may not be necessary insofar as the water which flows through the coil means 44 will be of relatively small volume per unit time, and the heat exchange rate may be such that the hot water issuing out of pipe 48 and rose 46 will be at a temperature which is comfortable to receive on the skin.

The coil body 44 and piping 48 provide simple and inexpensive method of ensuring that hot water water is supplied to the shower at sufficient pressure.

In conjunction with the coil 44 and piping 48 there may be provided an expansion chamber, for example as set forth in our co-pending application No. 2153504 to provide for uptake of thermal expansion of the water in the coil 44 for example in the event that there is no use of the shower over a long period and the water in the tank 44 is continuously heated. As the volume of water which will be thus continuously heated is relatively small, as explained in said co-pending application, the expansion chamber can be correspondingly small.

Also, the piping 48 may be provided with an anti-scald device as described in our copending application No. 8516025, and indeed these modifications can apply to each and et- ery embodiment of the present invention.

The coil means 44 may take any form. For example it may be in separate coil sections, it may comprise completely or partly of finned tubing, and in the arrangement of Fig. 1 it may be embodied within the cylinder of hot water tank 28 when it is manufactured, as distinguished from the arrangement shown in Fig. 2 which is in all respects identical to Fig.

1 except that the heat exchange coil means 44 is indicated as being inserted at the connection 44A in the tank 28. This represents an arrangement wherein the coil 44 is inserted in the tank 28 in order to modify an existing water installation. The piping 47, 48 will also have to be added but it performs the same function as the piping 48 referred to in Fig. 1.

In all other resepcts the Fig. 2 embodiment is identical to the Fig. 1 embodiment.

In the arrangement of Fig. 3, which again represents a modification of an existing system, a separate and smaller hot water tank 28A is provided, and this tank is hydraulically connected to the main water tank 28 by connecting pipes 60 and 62, these pipes coupling to pipes 42 and 38 respectively. As the water in the tank 28 is heated, so it will rise and travel along pipe 42 through pipe 60 into tank 28A and cold water will be displaced out of tank 28A through pipe 62 and along pipe 38 into tank 28. There will therefore be a circulation of water to ensure that the water in the tank 28A will be at the same temperature as that in tank 28. The heat exchanger coil 44 is contained in the separate tank 28A as shown, and the coil is again, connected by piping 47, 48 to the mains inlet 34 and to the shower rose 46. The water in coil 44 receives heat from the hot water in tank 28A, and as the shower is operated and the mains water passes through coil 44 receiving heat as it does, so there will be a cooling of water in tank 28A and again there will be a circulation of hot water from the tank 28 through the tank 28A as described hereinbefore.

The tank 28A is provided with insulation 64.

The Fig. 3 embodiment represents a simple and effective method of converting an existing domestic water installation to provide for hot water at mains pressure for effective showering.

The modification of Fig. 3 can be effected simply by tapping the relevant connections into the existing pipework, and no modification of the cylinder 28 is required.

Because the flow rate for a shower is small, only a relatively small heat exchange coil means 44 would be required.

Claims

1. A water heating apparatus for supplying hot water to a shower rose including a heat exchange coil means through which water at or driven by mains pressure is supplied and from which the water duly heated by passing through said coil means is delivered to the shower rose, the said water for the shower rose receiving heat by heat exchange with a body of hot water within the apparatus.

2. A water heating apparatus according to Claim 1, wherein the water heating apparatus comprises a secondary tank for secondary hot water, a boiler for heating the secondary hot water, and wherein said secondary hot water provides the source of heat for heating the water which passes through said heat exchange coil means.

3. A water heating apparatus according to Claim 2, wherein the secondary tank is surrounded by insulating material.

3. A water heating apparatus according to Claim 2, wherein said heat exchange coil means is contained in said secondary tank.

4. A water heating apparatus according to Claim 2, wherein said heat exchange coil means is located outside the secondary tank but in a smaller sub-tank whose interior is in hydraulic communication with the secondary tank so that hot water from the secondary tank circulates through the sub-tank.

5. A water heating apparatus according to Claim 4, wherein said sub-tank is surrounded by insulating material.

6. A water heating apparatus substantially as hereinbefore described with reference to Fig. 1, Fig. 2 or Fig. 3 of the accompanying drawings.

CLAIMS Amendments to the claims have been filed, and have the following effect: Claims 1-5 above have been deleted or textually amended.

New or textually amended claims have been filed as follows:

1. A domestic water heating apparatus comprising a boiler for heating primary water, a water tank for holding a body of secondary water supplied from the mains, a first heat exchanger coil in the water tank, means enabling circulation of primary water from a boiler to the first heat exchanger coil and back to the boiler for heating of the secondary water, a second heat exchanger coil in the tank adapted to be supplied with water from the mains and coupled to a shower rose so that water supplied from the mains and which passes though the second heat exchanger coil is heated by the body of secondary water before passing to the shower rose.

2. A domestic water heating apparatus comprising a boiler for heating primary water, a primary water tank for holding a body of secondary water supplied from the mains, a first heat exchanger coil in the primary water tank, means enabling the circulation of primary water from the boilerwthrough the first heat exchanger coil and back to the boiler for the heating of the body of secondary water, a secondary water tank in hydraulic communication with the primary tank so that heated secondary water circulates from the primary tank to the secondary tank and back to the primary tank, a second heat exchanger coil in the secondary tank adapted to be supplied with water from the mains and coupled to a shower rose so that water supplied from the mains which passes through the second heat exchange coil is heated by the secondary hot water in the secondary tank before passing to the shower rose.