AU2007214261A1

AU2007214261A1 - Hot water system

Info

Publication number: AU2007214261A1
Application number: AU2007214261A
Authority: AU
Inventors: Noel Burley
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-02-09
Filing date: 2007-02-09
Publication date: 2007-08-16
Anticipated expiration: 2027-02-09
Also published as: AU2007214261B2; WO2007090238A1

Description

1 HOT WATER SYSTEM Technical Area The Invention relates to a hot water system, and in particular, to a system which minimizes water waste. Background to the Invention In most domestic buildings, and many commercial buildings the outlet from the hot water heater can have a number of branches as it is connected to taps in various rooms in the building, normally the kitchen, the bathroom, the laundry, and often a toilet or toilets. Generally if hot water is not being used, the temperature of the water in the delivery pipes cools and when the water is first caused to flow, there is a lesser or greater amount of cold water delivered, the water being that in the pipes between the tap concerned and the hot water tank and until this has been run through the water is generally not used. At this time, many countries, and particularly cities do not have a surfeit of water and substantial quantities of water are lost, by simply being passed to waste. There have been proposals to divert this water to other usages, such as on a garden, but these necessitate, either a timed valve or a thermostat valve whereby when the water initially flows it is diverted and after a particular time or when it reaches a particular temperature it is connected to the outlet which is being used. Such arrangements are expensive and to be of great value they need be associated with each outlet or at least each outlet which is any substantial distance from the hot water supply. Y:\SPEC\Burlecy N Hot Water System CAP 02 02 07.wpd 8/2107 2 Alternatively and in many commercial buildings the hot water system is one which is circulatory and in this case the hot water pipelines are caused to pass from outlet to outlet and then back to the source of hot water. A pump is provided in the line so that water is caused to circulate at all times and provided the loop terminates close to individual outlets there is effectively instantaneous hot water available at these outlets. These systems are less than satisfactory, particularly in buildings where there are long periods where water is not used as there is the cost of operating the pump and reheating the water as it circulates, as an ongoing cost and the substantial cost of effecting the plumbing in a manner which is satisfactory for use with such a system which normally necessitates a return line which extends at least the distance from the hot water tank to the furthest outlet from the tank. Outline of the Invention It is the object of the present invention to minimize the disadvantages of the previous systems whilst providing effectively immediate hot water at any outlet in a system. The invention includes a hot water system in which, in the pipes from the source of hot water connected to the individual hot water outlets, there are small diameter pipes which reflect the layout of the normal piping arrangement and wherein there is a pump in connection with the outlet from the source of hot water, the outlet of which pump is connected to the small diameter pipes and from which water is passed from adjacent the source of hot water along the small diameter pipes and delivered adjacent to each outlet, the water displaced being forced back towards the hot water system. The invention also includes a method of retaining hot water in a hot water supply system comprising in the pipes from the source of hot water and connected to the individual hot water outlets there are small diameter pipes which reflect the layout of the normal piping arrangement and wherein there is a pump in connection with the Y:\SPEC\Burley N Hot Water System CAP 02 02 07.wpd 8/2/07 3 outlet from the source of hot water, the outlet of which pump is connected to the small diameter pipes and from which water is passed from adjacent the hot water supply along the small diameter pipes and delivered adjacent to each outlet, the water displaced being forced back towards the hot water system wherein the pump is operated when there is not hot water being drawn through a tap causing a low volume flow of hot water through the system to maintain the temperature of the water therein. Preferably the pump is physically located close to the outlet from the hot water system, has an inlet from that outlet. In an alternative form, the pump ,ay be mounted in a chamber in the outlet from the hot water system and draws water directly from this. Description of an Embodiment of the Invention in order that the invention may be more readily understood one embodiment of this will be described in relation to the accompanying drawing which shows a schematic view of the system. There is a hot water supply tank 10 which may be heated in any normal way, normally by electricity, gas or solar energy and which has an inlet 11 which is connected to the mains reticulated supply and may have a pressure reducing valve therein to limit the pressure through the system, and an outlet 12 which supplies water to the individual hot water outlets which are shown at 13. For ease of description these shall be referred to as taps but they could include inlets to washing machines and dishwashers whether or not there is a tap or some other type of valve associated therewith. Y:\SPEC\Burley N Hot Water System CAP 02 02 07.wpd 8/2/07 4 In the illustrated embodiment, there is a pump 20 physically located adjacent the outlet 12 from the hot water supply tank and which has an inlet from that system. In an alternative, the outlet 12 from the tank includes an enlarged portion in which is located a pump and can be considered to be a compartment having one side which can be removed to obtain access to the pump and may be provided with a pressure gland or the like through which the power supply to the pump can be passed. In each case, the pump itself can be a low volume pump and, particularly in the second embodiment which is adapted to be submersed in hot water would preferably be of stainless steel, brass, or some other metal which is not substantially corrodible by hot water. Normally the pump will be a vane pump, but this is not critical to the invention. The outlet of the pump is adapted to receive a capillary pipe 21 which is of substantially smaller diameter than the delivery pipe 22 to the taps. Depending upon the application the delivery pipe can be of the same size as normal delivery pipe, often in domestic applications considered to have approximately a half inch internal diameteror could be slightly larger so that the total volume, excluding the volume occupied by the capillary pipes could be effectively the same as in a conventional supply. The capillary pipe 21 isjoined and has junctionswherever the main pipe has a junction, that is if there is a T member as at 23 by means of which a particular tap is provided with water then there is a T connection of capillary pipe located within the T member. Because the capillary pipe can be substantially flexible, it does not have to be extremely accurately located, provided it can pass down the branch 24 from the T. The junctions of the capillary pipes can be formed as the junctions in the supply pipes are formed. Y:ASPEC\Burley N Hot Water- System CAP 02 02 07.wpd 8/2/07 5 At its free end, this branch is provided with connection means whereby it can be connected to a tap 13 and as such pipe very often plastics or flexible hoses in modern plumbing systems a normal terminator can be provided to enable the tap to be connected. The capillary pipe 21 can be at such a length as to terminate just before the inlet to the tap. It will be appreciated then that when the plumbing system is completed there are capillaries terminating closely adjacent to each tap and each capillary is in connection with a line which passes from the pump within the normal distribution pipe work. In operation, where no water is being drawn,the pump can operate to pass water along the capillaries where it will leave the capillary close to the inlet to it's associated tap and this will slightly increase the pressure in the pipework and the water already in the pipe will be forced to move towards the hot water tank and ultimately will pass along the supply pipe and to the tank, or at least be closely adjacent to this. If the water passes into the tank, then it will of course be heated to the temperature of the reminder of the water in the tank if closely adjacent it will still be heated to close to this. As long as no water is being drawn from the system the system will come to equilibrium with hot water being in each branch adjacent to each tap. When a tap is turned on, then of course the main flow of water passes direct from the hot water tank through the normal reticulation line and to the tap 13. Thus the initial flow of water will be effectively the temperature at which the water has left the capillary adjacent the tap, the water which is the water which is being returned because of the Y:\SPEC\Birley N Hot Water System CAP 02 02 07.wpd 8/2/07 6 water in the capillary will be next passing through the tap at which time the water from the hot water system itself will pass through the tap. It will be seen depending upon the volume of water passing through the capillary at any time there should be little change in temperature from the time the tap is first turned on until the flow from the storage tank passes from the tank to the tap. The rate of operation of the pump is controlled to maintain the required temperature in the system. Also because there is warm to hot water in the pipes at all times there would be no reduction of temperature due to the internal surface of the pipe being at a low temperature relative to the temperature of the water from the storage tank. It will been seen that the system of the invention provides effectively immediately available hot water as soon as a tap is open and once the tap is closed then the small volume re-circulation will commence so that when another tap is later opened the same effect occurs. It will be appreciated that modifications can readily be made in the invention. For example a compartment in which the pump can be located could be built into the side of the hot water system so that the spacing between the outlet of the hot water tank and the pump will be minimal it will also be understood that if required several branches could be used, particularly in larger installations each of which having it's own pump so that a larger number of taps, particularly those spaced a substantial difference from the others can be properly maintained to provide hot water. These and other modifications are deemed to be with the scope of the invention. Y:1SPECButrey N Hot Water System CAP 02 02 07.wpd 8/2/07 7 I claim: 1. A hot water system in which, in the pipes from the source of hot water and connected to the individual hot water outlets there are small diameter pipes which reflect the layout of the normal piping arrangement and wherein there is a pump in connection with the outlet from the source of hot water, the outlet of which pump is connected to the small diameter pipes and from which water is passed from adjacent the hot water supply along the small diameter pipes and delivered adjacent to each outlet, the water displaced being forced backtowards the hot water system. 2. A hot water system as claimed in claim 1 wherein the hot water supply is a tank. 3. A hot water system as claimed in claim 2 wherein the pump is located close to the outlet from the hot water tank. 4. A hot water system as claimed in any preceding claim wherein the pump is located in the pipes. 5. A hot water system as claimed in claim 4 wherein there is a chamber attached to or adjacent the source of hot water in which the pump is located. 6. A method of retaining hot water in a hot water supply system comprising in the pipes from the source of hot water and connected to the individual hot water outlets there are small diameter pipes which reflect the layout of the normal piping arrangement and wherein there is a pump in connection with the outlet from the source of hot water, the outlet of which pump is connected to the small diameter pipes and from which water is passed from adjacent the hot water supply along the small diameter pipes and delivered adjacent to each outlet, the water displaced being forced back towards the hot water system wherein the Y:\SPEC\Burley N Hot Water System CAP 02 02 07.wpd 8/2/07 8 pump is operated when there is not hot water being drawn through a tap causing a low volume flow of hot water through the system to maintain the temperature of the water therein. 7. A hot water system substantially as hereinbefore described with reference to the accompanying drawing. 8. A method of retaining hot water in a hot water supply system substantially as hereinbefore described with reference to the accompanying drawings. Y:\SPECBurley N Hot Water System CAP 02 02 07.wpd 8/2/07

Claims

1. A hot water system in which, in the pipes from the source of hot water and connected to the individual hot water outlets there are small diameter pipes which reflect the layout of the normal piping arrangement and wherein there is a pump in connection with the outlet from the source of hot water, the outlet of which pump is connected to the small diameter pipes and from which water is passed from adjacent the hot water supply along the small diameter pipes and delivered adjacent to each outlet, the water displaced being forced backtowards the hot water system.

2. A hot water system as claimed in claim 1 wherein the hot water supply is a tank.

3. A hot water system as claimed in claim 2 wherein the pump is located close to the outlet from the hot water tank.

4. A hot water system as claimed in any preceding claim wherein the pump is located in the pipes.

5. A hot water system as claimed in claim 4 wherein there is a chamber attached to or adjacent the source of hot water in which the pump is located.

6. A method of retaining hot water in a hot water supply system comprising in the pipes from the source of hot water and connected to the individual hot water outlets there are small diameter pipes which reflect the layout of the normal piping arrangement and wherein there is a pump in connection with the outlet from the source of hot water, the outlet of which pump is connected to the small diameter pipes and from which water is passed from adjacent the hot water supply along the small diameter pipes and delivered adjacent to each outlet, the water displaced being forced back towards the hot water system wherein the WO 2007/090238 PCT/AU2007/000131 8 pump is operated when there is not hot water being drawn through a tap causing a low volume flow of hot water through the system to maintain the temperature of the water therein.

7. A hot water system substantially as hereinbefore described with reference to the accompanying drawing.

8. A method of retaining hot water in a hot water supply system substantially as hereinbefore described with reference to the accompanying drawings.