GB2459307A

GB2459307A - Method and apparatus for collecting rainwater from the roof of a building

Info

Publication number: GB2459307A
Application number: GB0807174A
Authority: GB
Inventors: Alex Honey
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-04-19
Filing date: 2008-04-19
Publication date: 2009-10-21
Also published as: GB0807174D0

Abstract

A rainwater harvesting system comprises a collecting element in communication with water tank, wherein the collecting element is provided on a suitable surface of a building and the water tank is provided within the roof of the building.

Description

Method and Apparatus for Collecting Water

Field of the Invention

The present invention relates to a system for collecting water, especially rainwater, and to a method of making a rainwater collecting system, a method of collecting rainwater, and to apparatus for use in the system/method.

Background of the Invention

In many parts of the world a lack of water for drinking or irrigation is a significant problem. In addition, there is also a risk that following heavy rainfall, rainwater is quickly channelled to streams and rivers, thus increasing the risk of flooding. Shortages of water are leading to the introduction of water meters which will consequently lead to an increase in the price of water from the mains water supply. The collection of rainwater (known as "rainwater harvesting") will become increasingly important in future years and several public bodies are encouraging people to consume less water in the home, as part of a drive to conserve resources.

In view of the above, systems are being developed for harvesting rainwater which is sufficiently clean such that it may be suitable for a number of different uses. The provision of rainwater harvesting systems has involved the building of large water tanks (typically having a capacity of greater than 3000 litres) in, for example, buried in the garden of a house. Once buried, these tanks are backfilled with concrete to avoid them becoming buoyant when empty of rainwater.

However, the installation of water tanks presents several problems to the developer: (1) when inserting a tank into the ground it is necessary to create a large, deep hole which may raise various health and safety issues; (2) the installation of water tanks extends the time period required for building a house, thus requiring more labour to be provided on site; (3) modem housing developments often have small gardens which may be too small to accommodate a large water tank; and (4) when inserting a water tank in the ground, around 5 tonnes of soil is typically removed and must be placed in an alternative location. This is becoming increasingly difficult, especially in urban areas.

The present invention provides a rainwater harvesting system and a method of making a rainwater harvesting system, each of which helps to reduce or overcome the above problems.

Summary of the Invention

In a first aspect, the invention provides a rainwater harvesting system comprising a collecting element for collecting rainwater and a water tank for storing collected rainwater, wherein the collecting element is provided on a collection surface of a house or other building and the water tank is provided within the roof space of the house or other building, and wherein the collecting element is in communication with the water tank such that the rainwater collected by the collecting element passes to the water tank where it is stored.

In preferred embodiments, the water tank is positioned at a height above the locations in or around the house or other building in which the stored water is to be dispensed or used, such that water can flow from the tank to the dispensing/usage locations under gravity, without requiring a pump or other motive means. Also in preferred embodiments, the collecting element is higher than the water tank, such that rainwater collected by the collecting element can pass into the water tank under gravity.

Thus, in preferred embodiments, the collected rainwater can be fed into the storage tank and thence transferred to the dispensing/usage locations entirely passively, e.g. under the influence of gravity.

Preferably the collecting element is substantially in the form of a gutter or guttering. The collecting element is preferably located on the exterior surface of the roof of the house or other building so as to collect rainwater, the collection surface being the exterior of the roof. The collecting element will typically be located on the roof below the apex thereof but above the bottom edge of the roof.e.g. typically between � and 3/4 of the way down the roof from the apex.

Obviously, the lower down on the roof the collecting element is located, the greater the area of the collecting surface and hence the greater volume of rainwater that can be collected. However, the lower the collecting element, the less the "head" above the water tank, such that the collected water is less likely to flow passively into the water tank. Conveniently.communication between the collecting element and the water tank is provided by a pipe hose, or other conduit, preferably an enclosed conduit. Advantageously the pipe hose, or conduit is flexible to facilitate connection at one or both ends to the tank and/or collecting element respectively. Typically the pipe, hose, or conduit is of sufficient internal area or bore to accommodate likely peak flows of rainwater during heavy rainfall. For example, the pipe may conveniently have a bore in the range of 3Omm-200mm, preferably in the range 40-150mm. It is envisaged that for domestic properties a pipe diameter is likely to be between 40mm and 60mm. The pipe hose or conduit may satisfactorily be formed from thin sheets of metal or, more preferably a synthetic plastics material such as polyproplylene, polyethylene or the like.

Typically, an end region of the collecting element is provided with an outlet for connection to the pipe hose or conduit so that the rainwater collected by the collecting element can be fed into the water tank.

Preferably, the outlet of the collecting element is higher than an inlet into the water tank, such that the collected rainwater can be fed into the storage tank and thence transferred to the dispensing/usage locations entirely passively, e.g. under the influence of gravity.

Conveniently, the outlet is provided with a nozzle or other attachment means, for example a screw fitting or snap fit, to facilitate attachment of the pipe hose or conduit to the outlet. Any type of attachment may be employed between the pipe, hose or conduit and the outlet, but should preferably be releasable and substantially water-tight.

Similarly, a region of the water tank is provided with an inlet for connection to the pipe hose, or conduit so that the rainwater collected by the collecting element can be fed into the water tank.

Advantageously, the inlet is provided with a nozzle or other attachment means, for example a screw or snap fit, to facilitate attachment of the pipe, hose or conduit to the inlet. Any type of attachment may be employed between the pipe, hose or conduit and the inlet, but should preferably be releasable and substantially water tight.

In some embodiments the collecting element slopes downwards along it's length, either entirely or in part, to facilitate the passage of water from the collecting element to the water tank.

Preferably, the collecting element comprises stainless steel, aluminium or a synthetic plastics material such as PVCu. Typically, the collecting element forms a shallow well within which rainwater may be collected. The collecting element preferably has a depth of between 20mm and 100mm, more preferably between 30mm and 80mm, and most typically about 50mm.

Conveniently, one or more hook elements are provided along a side and/or an edge of the collecting element. The provision of such hooks allows the collecting element to be fitted over the edge of a roof tile.

In one embodiment, the collecting element may be fitted onto the surface of plain roof tiles.

Preferably, one side or edge of the collecting element is provided with a hook, which may be fitted over the edge of the roof tiles to hold the collecting element in position. The hook may be formed, for example, from folded or pressed metal, such as steel.

In another embodiment, the collecting element of the present invention may. be fitted onto pantiles. Preferably, metal tile clips are attached to a side or an edge of the collecting element by means of a spot weld or rivet connection. Desirably, a flexible plastics sheet is positioned to extend across the surface of the metal tile hooks and may be glued or otherwise fixed to the collecting element. A compressible foam strip may be positioned to extend across the surface of the hooks and may advantageously be provided at one edge of the flexible plastics strip, to reduce any gaps between the tiles and the hooks. The metal tile hooks are preferably fitted over the edge of the pantiles, thus holding the collecting element in position.

Filter means are conveniently provided on or within the collecting element such that debris in the rainwater can be excluded from the water collected by the collecting element. In a preferred embodiment, a filter is provided across a surface of the collecting element. More preferably, the filter is provided across an upper surface and extends substantially along the entire length of the collecting surface. The filter is typically formed from a fine metal gauze and may be fixed in position by means of a continuous weld or glue. Typically the filter comprises a mesh, preferably having a mesh size of between 1mm and 10mm, preferably between 1mm and 2mm.

The metal gauze advantageously prevents or reduces the collection of leaves, insects and other debris which may contaminate the collected rainwater. Preferably, a synthetic plastics insert is provided at respective ends of the collecting element to provide a support for the metal gauze, The synthetic plastics insert may be formed from polypropylene, polyethylene or PVCu.

Advantageously, the rainwater harvesting system of the present invention is partially self-cleaning. It is envisaged that during periods of very heavy rain some overflowing of the collecting element occurs, which may then provide an element of "backwashing" the gauze, to help maintain its efficiency.

The water tank of the system is typically formed substantially of a material, preferably a plastics material, which is light enough to enable it to be stored in the roof of a house, but strong enough to retain a substantial volume of collected water. Suitable materials include a thin sheet metal or, more preferably a synthetic plastics material such as polypropylene or polyethylene. The water tank may be linked to a mains water feed, such that in periods of dry weather, a small amount of potable water may be fed into the system.

Preferably, the water tank may accommodate a volume of between 200-800 litres of water, more preferably between 400-600 litres of water and most preferably around 500 litres of water.

In one embodiment, two or three plastic water tanks may be arranged in series. Typically, a first water tank is in communication with the collecting element or elements, and the other tanks are linked to the first tank by means of a further pipe. Alternatively, in another embodiment, each water tank is individually in communication with one or more collecting elements. This has the advantage that the water tanks do not need to be in close proximity to one another, such that the weight of the water tanks can be distributed across a larger surface area of the roof space.

The water tank is preferably provided with a lid or cover to prevent ingress of foreign bodies, for example rats, mice etc. The lid or cover may be present on a water tank of a system that has been placed in a house during building, or to a system that has been retrofitted to an existing building.

A conventional gutter (outside the scope of the present invention) will normally be present to channel excess rainwater from the roof of the house to the ground. Preferably, the conventional gutter comprises a metal or PVCu pipe. Typically, the conventional gutter is in liquid flow communication with the lowermost edge of the roof and further communicates with a downpipe which runs alongside the outer wall of the house until it reaches a point near the ground.

The water tank of the system of the invention is conveniently provided with an overflow means to lead excess collected rainwater away from the system. Preferably, the overflow means comprises an overflow pipe which extends from the water tank to a position close to the downpipe of the standard gutter. The overflow pipe then extends in a direction parallel to and runs alongside the downpipe until it reaches a point near the ground wherein a visual inspection point is provided to allow a person to view and monitor the amount of overflow from the water tank. The overflow pipe may conveniently be attached to the downpipe of the conventional gutter, or the overflow and the downpipe may be attached to the house by common brackets.

The rainwater harvesting system of the present invention is applicable in a wide variety of circumstances, from small developments to medium residential, commercial or industrial operations. Advantageously, the rainwater harvesting system may be installed during the building of a house or other edifice, or may successfully be retrofitted to an existing development.

Several significant advantages are provided by means of the arrangement according to the present invention. The rainwater harvesting system is easy to install and the water collected may be used for example, for flushing toilets, in washing machines, watering garden plants, washing cars, and the like.

In a second aspect, the invention provides a method of making a rainwater harvesting system in accordance with the first aspect of the invention, the method comprising the steps of: placing a collecting element onto a collection surface of a house or other building; providing a water tank within the roof space of the house or other building; and connecting the collecting element and the water tank such that water collected by the collecting element passes to the water tank where it is stored.

Preferably performance of the method results in the collecting element being positioned on the collecting surface such that the outlet of the collecting element is higher than an inlet into the water tank through which the collected water enters the tank. Preferably also, the outlet of the collecting element will be higher than the level of water contained within the tank.

Conveniently, the collection surface is angled downwards towards the collecting element, to facilitate the collection of water by the collecting element.

Preferably, the collecting element is located on the roof below the apex thereof but above the bottom edge of the roof. Typically, the collecting element is located on the roof between � and 3/4 of the way down the roof from the apex.

The method of making the rainwater harvesting system in accordance with the first aspect may be performed during construction of a house or other building. Alternatively, the system may be retrofitted to an existing house or other building.

The rainwater harvesting system may be fitted to a building by lifting one or more layers of tiles from a roof to attach the collecting element to a collection surface, replacing the tiles, attaching a flexible pipe, hose or conduit to the outlet of the collecting element, forming a suitable sized hole through the wall of the building, and connecting the free ends of the flexible pipe or conduit to the inlet of the water tank. Obviously, the order of attachment of the components could be altered as required.

In the cases when the system is retrofitted to a building it is advantageous for the water tank to be made from a collapsible material, such that it is easier to insert the system in the roof space.

In a third aspect, the invention comprises a collecting element comprising an outlet means for connecting the collecting element to a pipe, hose or conduit. An end region of the collecting element is typically provided with an outlet for connection to the pipe, hose or conduit so that the rainwater collected by the collecting element can be fed into the water tank.

Conveniently, the outlet is provided with a nozzle or other attachment means, for example a screw fitting or resiliently deformable snap fitting, to facilitate attachment of the pipe, hose or conduit and the outlet, but should preferably be releasable and substantially water-tight.

In a fourth aspect, the invention comprises a collecting element comprising one or more hook elements provided along a side and/or an edge of the collecting element. The provision of such hook elements conveniently allows the collecting element to be fitted over the edges of roof tiles.

In one embodiment in accordance with the fourth aspect, a flexible plastics sheet is positioned to extend across the surface of the one or more hook elements. Preferably, the flexible plastics sheet is fixed to the collecting element.

In another embodiment in accordance with the fourth aspect, a compressible foam strip is positioned to extend across the surface of the one or more hook elements.

In a further embodiment in accordance with the fourth aspect, a flexible plastics sheet is positioned to extend across the surface of the one or more hook elements, and a compressible foam strip is provided at the edge of the flexible plastics strip. Preferably, the flexible plastics sheet is fixed to the collecting element. The compressible foam strip reduces any gaps between the tiles and the hooks.

In a fifth aspect, the invention comprises a collecting element which is shaped and configured to allow the collecting element to fit essentially flush to the angled collecting surface. The profile along the long axis of the collecting element may further be adapted so as to provide a vertical fall along the collecting element to encourage rainwater to flow along the length of the collecting element.

In one embodiment, the invention comprises a collecting element in accordance with the third and fourth aspects as defined above. In other embodiments, the invention comprises a collecting element in accordance with the third and fifth aspects, or fourth and fifth aspects, as defined above.

In a sixth aspect, the invention provides a building comprising a rainwater harvesting system in accordance with the first aspect of the invention.

For the avoidance of doubt it is hereby expressly stated that any feature of the invention described herein as "preferred", "desirable", "convenient", "advantageous" or the like may be present in the invention in isolation, or in any combination with any one or more other features so described, unless the context dictates otherwise.

The invention will now be further described by way of illustrative example and with reference to the following drawings wherein: Figure 1 is a schematic view of the rainwater harvesting system in accordance with the first aspect of the invention; Figure 2 is a side elevation of part of the rainwater harvesting system in accordance with the first aspect of the invention in situ on a collection surface.

Figure 3 is a schematic view of one embodiment of a collecting element of the system of the invention, in situ on a collection surface; Figure 4 is a perspective view of another embodiment of a collecting element; Figure 5 is a perspective view of a yet another embodiment of a collecting element; Figure 6 is a perspective view, at a different scale, of an end of a collecting element showing an outlet for connection to a flexible pipe; and Figure 7 is a schematic view of an overflow arrangement for a rainwater harvesting system in accordance with the first aspect of the invention.

In the figures, functionally equivalent components are denoted by common reference numerals.

Detailed description of the Invention

With reference to Figures 1 and 2, a rainwater harvesting system is shown schematically. A collecting element, in the form of gutter (4) is placed on a collection surface provided by the exterior surface of the roof (6) of a house, at a position about half way down the roof from the apex. A flexible pipe (8) provides a link between the gutter (4) and a water tank (JO). The flexible pipe (8) has a bore of 50mm and is formed of polypropylene. The gutter (4) is provided at a position above the water tank, such that during periods of rainfall, rainwater is collected within the gutter and passes to the water tank by gravity, where it is stored until required. The water tank (10) is largely formed of synthetic plastics material and has a capacity of 500 litres. The water tank is suitable for collecting rainwater from the roof of a house having a roof area of 40m2. In addition to the gutter provided on the roof, a conventional gutter (12) is also provided (outside the scope of the present invention) to channel excess rainwater from the roof to the ground. The conventional gutter (12) is connected to a downpipe (17), and is in communication with the lowermost edge of the roof and runs alongside the outer side wall of the house until it reaches a point close to the ground.

Figure 3 shows a schematic sectional view of the gutter (4). The gutter (4) forms a trough within which rainwater is collected. An folded metal hook is provided along one side of the gutter (4) and allows the gutter to be fitted over the edge of a roof tile (13). A metal gauze (14) is fitted above the trough of the gutter (4) and is fixed in position by means of a glue or weld (16). The metal gauze (14) comprises a mesh having a pore size of about 1.5mm and acts as a filter to exclude from the trough leaves, insects, etc, which may contaminate the collected rainwater.

Figure 4 shows a perspective view of a gutter (4) which may be fitted onto plain roof tiles. A metal gauze (14) is fitted across the surface of the gutter (4) and is held in position by means of a glue. A continuous plastic insert (15), is provided along the length of the trough of the gutter, thus providing a support for the metal gauze. One side of the gutter (4) is provided with a folded metal hook (18a) which is fitted over the edge of the roof tiles to hold the gutter in position. The collecting element has a length of up to about Sm, a width of approximately 200mm and the trough of the gutter has a depth of about 50mm.

Figure 5 shows a perspective view of a gutter (4) which may be fitted to a roof covered with * pantiles. Metal tile clips (18) are attached to one side of the gutter by means of rivets (20). A flexible plastics sheet (22), extends across the upper surface of the metal tile clips and is glued to an edge of the gutter (4). A compressible foam strip (24) is provided along an edge of the flexible plastics sheet (22) to reduce and/or insulate any gaps between the tiles and the clips.

The metal tile clips (18) are fitted over the edge of the pantiles, thus holding the gutter (4) in position.

With reference to Figure 6, an end piece comprising a short threaded outlet pipe (24) is provided at one end of the gutter (4). The threaded outlet pipe facilitates attachment of a flexible pipe or hose to the collecting element. Conveniently the flexible pipe or hose is threaded to engage the threaded outlet pipe.

Figure 7 shows an overflow arrangement for a rainwater harvesting system in accordance with the present invention, which allows excess rainwater to be controllably removed therefrom. In the event of overflow, rainwater is removed from the water tank by means of an overflow pipe (26). The overflow pipe (26) hose bore approximately 150% of that of the flexible pipe (8, as seen in Figure 1). The overflow pipe (26) extends from the water tank to a point near the conventional guttering downpipe (17), and then extends in a direction substantially parallel to the downpipe (17). The overflow pipe and downpipe (17) are both attached to the wall of the house by means of common brackets (28). A visual inspection point (30) is provided at one end of the overflow pipe, to allow a person to view and monitor the amount of overflow from the water tank. This will ensure that if there is a fault and potable water is being wasted, the householder will be aware immediately.

The rainwater harvesting system of the present invention may be fitted onto the roof of a house during the building process, or alternatively may be retrofitted to the roof of a house after the house has been built. To assist in this regard the water tank, when empty, is preferably collapsible, to facilitate insertion into the roof space. The tank may, for example, be provided with collapsible struts or other rigidity -conferring means which can be deployed when the tank is in the desired location.

Claims

Claims 1. A rainwater harvesting system comprising a collecting element for collecting rainwater and a water tank for storing collected rainwater, wherein the collecting element is provided on a collection surface of a house or other building and the water tank is provided within the roof space of the house or other building, and wherein the collecting element is in communication with the water tank such that the rainwater collected by the collecting element passes to the water tank where it is stored.
2. A rainwater harvesting system in accordance with claim 1, wherein the water tank is positioned at a height above the locations in or around the house or other building in which the stored water is to be dispensed or used, such that water can flow from the tank to the dispersing/usage locations under gravity, without requiring a pump or other motive means.
3. A rainwater harvesting system in accordance with claim 1 or 2, wherein the collecting element is higher than the water tank, such that the rainwater collected by the collecting element can pass into the water tank under gravity.
4. A rainwater harvesting system in accordance with any one of the preceding claims, wherein the collecting element is substantially in the form of a gutter or guttering.
5. A rainwater harvesting system in accordance with any one of the preceding claims wherein the collecting element is located on the exterior surface of the roof of the house or other building so as to collect rainwater, the collection surface being the exterior of the roof
6. A rainwater harvesting system in accordance with any one of the preceding claims wherein communication between the collecting element and the water tank is provided by a pipe, hose or other conduit.
7. A rainwater harvesting system in accordance with claim 6, wherein an end region of the collecting element is provided with an outlet for connection to the pipe, hose or conduit so that the rainwater collected by the collecting element can be fed into the water tank.
8. A rainwater harvesting system in accordance with claim 7 wherein the outlet is provided with a nozzle or other attachment means, for example a screw fitting or snap fit, to facilitate attachment of the pipe, hose or conduit to the outlet.
9. A rainwater harvesting system in accordance with any one of claims 6 to 8 wherein the water tank is provided with an inlet for connection to the pipe, hose or conduit so that the rainwater collected by the collecting element can be fed into the water tank.
10. A rainwater harvesting system in accordance with claim 9 wherein the inlet is provided with a nozzle or other attachment means, for example a screw or snap fit, to facilitate attachment of the pipe, hose or conduit to the inlet.
11. A rainwater harvesting system in accordance with any one of the preceding claims wherein the collecting element slopes downwards along its length, either entirely or in part, to facilitate the passage of water from the collecting element to the water tank.
12. A rainwater harvesting system in accordance with any one of the preceding claims wherein one or more hook elements are provided along a side andlor an edge of the collecting element, to allow the collecting element to be fitted over the edge of a roof tile.
13. A rainwater harvesting system in accordance with claim 12 wherein a flexible plastics sheet is positioned to extend across the surface of the one or more hook elements.
14. A rainwater harvesting system in accordance with any one of claims 12 or 13 wherein a compressible foam strip is positioned to extend across the surface of the one or more hook elements.
15. A rainwater harvesting system in accordance with claim 14 wherein the compressible foam strip is provided at one edge of the flexible plastics strip, to reduce any gaps between the tiles and the hooks.
16. A rainwater harvesting system in accordance with any one of the preceding claims wherein filter means are provided on or within the collecting element such that debris in the rainwater can be excluded from the water collected by the collecting element.
17. A rainwater harvesting system in accordance with claim 16 wherein a synthetic plastics insert is provided at respective ends of the collecting element to provide a support for the filter means.
18. A rainwater harvesting system in accordance with any one of the preceding claims wherein the water tank is linked to a mains water feed such that, in periods of dry weather, a small amount of potable water may be fed into the system.
19. A rainwater harvesting system in accordance with any one of the preceding claims wherein the water tank is provided with an overflow means to lead excess collected rainwater away from the system.
20. A method of making a rainwater harvesting system in accordance with any one of the preceding claims, the method comprising the steps of: placing a collecting element onto a collection surface of a house or other building; providing a water tank within the roof space of a house or other building; and connecting the collecting element and the water tank such that water collected by the collecting element passes to the water tank where it is stored.
21. A method of making a rainwater harvesting system in accordance with claim 20 wherein the method may be performed during construction of a house or other building.
22. A method of making a rainwater harvesting system in accordance with claim 20 wherein the system is retrofitted to an existing house or other building.
23. A method of making a rainwater harvesting system in accordance with claim 21 or 22 wherein the water tank is collapsible, such that it is easier to insert the system in the roof space.
24. A collecting element for use in the system of claim 1, comprising an outlet means for connecting the collecting element to a pipe, hose or conduit.
25. A collecting element for use in the system of claim 1, comprising one or more hook elements provided along a side andlor an edge of the collecting element.
26. A collecting element in accordance with claim 25 wherein a flexible plastics sheet is positioned to extend across the surface of the one or more hook elements.
27. A collecting element in accordance with claim 25 or 26 wherein a compressible foam strip is positioned to extend across the surface of the hook elements.
28. A collecting element in accordance with claim 27 wherein the compressible foam strip is provided at one edge of the flexible plastics strip.
29. A collecting element for use in the system of claim 1, which is shaped and configured to allow the collecting element to fit essentially flush to an angled collecting surface.
30. A collecting element according to claim 29 and further in accordance with any one of claims 24 to 28.
31. A collecting element in accordance with any one of claims 24 to 30 wherein the profile along the long axis of the collecting element is further adapted so as to provide a vertical fall along the collecting element to encourage rainwater to flow along the length of the collecting element.
32. A building comprising a rainwater harvesting system in accordance with any one of claims ito 23.
33. A rainwater harvesting system substantially as hereinbefore described and with reference to the accompanying drawings.
34. A method of making a rainwater harvesting system substantially as hereinbefore described and with reference to the accompanying drawings.
35. A collecting element substantially as hereinbefore described and with reference to the accompanying drawings.