GB2463955A

GB2463955A - Apparatus for collection and storage of rainwater

Info

Publication number: GB2463955A
Application number: GB0907159A
Authority: GB
Inventors: Adrian Lester
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-10-05
Filing date: 2009-04-20
Publication date: 2010-04-07
Also published as: GB0818131D0; GB2463990A; GB0917265D0; GB2463955A9; GB0907159D0; GB2463990B

Abstract

Apparatus for the collection and storage of rainwater falling onto a building comprises a header tank 6 for storing rainwater equipped with level sensors (D, diagram 3), and a controller 5 capable of operating in different modes. Preferably, the apparatus includes an underground rainwater storage tank 3 and an electric pump 4 controlled by the controller. If the rainwater in the underground storage tank runs out, the controller may operate to fill the header tank with water from the mains. A 'commissioning' mode may be used to automatically calibrate the apparatus, by recording the time taken to fill the tank, in the event of an upper sensor failing in the header tank. An 'auto tank refresh' mode may be operable to flush out the system if the header tank is not used in any three day period, to prevent the rainwater from becoming discoloured and stale. A 'holiday mode' may be used if the building is being left empty, in which the header tank is emptied and refilled with mains water. In the event of a power cut a mains water supply valve may be manually opened and the header tank filled with mains water.

Description

Apparatus for optimising the collection and storage of rain falling onto a building by managing the supply of this rainwater for use around the building.

The invention will be described by referring to the accompanying diagrams.

1) Diagram 1: schematic overview of building Rain is collected off the roof and fed by gravity through normal gutters (Diagram 1, 1) and downpipes (2) to the underground storage tank (3). A submersible electric pump (4) supplies rainwater via a multi-function Controller (with buttons, mode indicator lights, a microprocessor-board and solenoid valves) (5) (see below) to a specially-equipped Header Tank (6) (see below) in the roof space. Water flows by gravity as required through a dedicated network of pipes (7) to those appliances round the building which

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do not require potable water (notably, in the UK, toilets, washing machine (8) and garden taps).

One of the Invention's functions is as an automatic mains water backup.

Mains water (9) is available at the Controller to replenish the Header Tank, if *:*.; no rainwater is available.

The rainwater feed pipe (10) and the flush pipe (11) (which enables the Header Tank to be emptied as required) are also commanded by the Controller.

2) Diagram 2: Controller The Controller with its water valves can be located on a wall in a visible place on the ground floor (in a utility room or kitchen) or where convenient. The microprocessors and associated components are mounted on a printed circuit board and housed in the watertight control unit (Diagram 2, A). The on-off switch, other buttons and indicator lights are mounted on the control unit and accessible by the user. The Controller is powered by a 12 volt electric supply (B) fed from a wall-socket-mounted mains converter. Another wire (C) to the control unit brings signals from the sensors in the Header Tank.

A third wire (not shown) commands the opening and closing of the three solenoid valves (D, E, and F). Solenoids, water pipes and control unit are mounted on a back panel and protected by a moulded cover (H) with an aperture for viewing the indicator lights and manipulating the control unit buttons (A). A manual valve (G) permits the user to turn on mains water feed to the Header Tank even in the case of a power cut.

2 level sensors in the Header Tank (see below) provide a "tank full" or "tank empty" signals to the computer built in to the control unit of the * 20 Controller, which then controls 3 electrically operated water valves alongside: * *. * 1. The electric solenoid valve for rainwater (E) controls the inflow of pumped **S.

: water from a 240 volt pressure-sensitive pump in the underground rain water storage tank. When the valve opens, the pump registers the drop in pressure and supplies water to the Header Tank until a "tank full" signal from the closes the valve. Rainwater flow is upwards, from the * underground storage to the Header Tank.

2. The electric solenoid valve for mains water (F) is connected to the mains water supply. This is used mainly as a back up water supply if the rainwater should run out. Mains water flow is upwards, from the mains * 30 water supply to the Header Tank.

3. In the event of a power supply failure the manual mains water bypass (G) can be opened by hand and the tank will fill with mains water until the conventional ball cock in the Header Tank closes.

4. The electric flush valve (D) can be opened by the system to let water out at any time. Water flow is downwards, from the Header Tank back to the underground storage tank.

3) Diagram 3: Header Tank The Header Tank is normally situated in the roof space or anywhere in the building above the highest appliance to which water is to be fed by gravity.

The rainwater supply pipe (Diagram 3, A) enters near the top of the tank and is routed to the bottom of the tank, to reduce turbulence or splash. The mains water supply pipe (B) enters near the top of the tank through its ball cock valve (C) which stops the flow of mains water when the tank is full and which therefore prevents overflow of the mains water even when there is no electrical power. To provide the air gap required by U.K. building regulations, for the purpose of eliminating the risk of contamination of mains water by rainwater, the mains water flows into the tank from above the surface of the water. *..

: There are no user controls in the Header Tank. Two float sensors (D) *.. . "* 20 register the upper and lower water levels within the tank and inform the programme logic in the control unit.

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The overflow tower (E) in the Header Tank is a large, open-topped, *I..

* watertight cylinder whose top is below the top of the tank. If all other systems ".. 25 were to fail, and rain or mains water is flowing unchecked into the Header Tank, the excess water flows over the top of the cylinder and out of the 40mm overflow pipe (F) to the outside of the building. The large diameter overflow tower provides the head and impulsion to ensure high volume flow through the overflow pipe. Despite this provision, UK Building Regulations require an A-B Gap (G), a rectangular opening which is situated in the back of the Header Tank to further prevent contamination of mains water by rainwater; the water level in the tank could not reach the level of the mains water inlet pipe because it would have flowed out of the A-B gap. The overflow tower in the Header Tank of the invention prevents water flowing out of the A-B gap or over the top edges of the tank itself into the roof space by allowing excess water to flow down the overflow tower.

Water flows from the Header Tank through the outlet pipe (H) near the bottom of the tank.

4) Normal Running During normal use the Controller monitors and maintains the availability of rainwater in the tank. The Power On indicator light is on. The Rain filling light flashes when rain water is being pumped into the Header Tank.

Should the rainwater run out or become otherwise unavailable, the system automatically switches to mains water and the Mains filling light begins flashing. In exceptional circumstances, the functioning mode of the invention is changed automatically using the control unit buttons, as follows.

5) Setup Mode The set-up (or "commissioning" mode) is used once after installing when the user or installing engineer press both the flush and holiday buttons . : at the same time. This process last several hours and automatically calibrates *. the flow timers and stores in memory the time it takes for the rain water to fill *... 20 the tank and for the mains water to fill the tank. At any time in normal use * thereafter, if the top sensor fails, the tank fills with rain water (if available) or * mains water according to the time intervals memorised.

The reason why the time intervals have to be calibrated for each **. installation of the invention is because different sized Header Tanks, different water pressures and other variables make it impossible to establish the fill times as a factory setting. Calibration of the flow timers by set-up mode only needs to be completed once in the system's lifetime unless a new Header Tank or pump is fitted.

During the set-up process the Power On light flashes. The tank fills with rainwater, flushes, fills with mains water and flushes... then repeats the process two more times. The computer takes the average of the fill time for rainwater and for mains water and stores these two values. During these cycles, the Rain Filling, Mains filling and Flush indicator lights come on and off. The set-up may therefore take several hours. The user can interrupt the process if absolutely necessary but would have to run it again to complete the installation.

s 6) Auto Tank Refresh If the water in the Header Tank is not used in a 3-day period, the refresh program automatically flushes out the system, emptying the Header Tank back into the underground tank. The header then refills with fresh rainwater. This feature is disabled when the holiday mode is running (see (8) below). If the building is left empty, and the holiday button is not pressed, the Controller automatically refreshes the system every 3 days. The purpose of refresh is to prevent bacterial action making the rainwater in the Header Tank (which in a roof space in summer could be at 20°C or higher) from getting stale and discoloured; cool clear water from the underground tank (at about 5°C or less) is pumped into the header and bacterial action prevented.

7) Flush Mode The flush mode allows the rainwater in the Header Tank to be **S.

.. : changed by pressing the flush button on the panel. When the valve is opened S.. * the water will flush out and is directed back into the rainwater-harvesting tank.

This might be triggered if little water has been used and the ambient temperature is high; this gives the user the choice to avoid staleness and S. * discolouration by replacing the water in the Header Tank. This is the same as *:::: Auto Tank Refresh but triggered manually. S. *

8) Holiday Mode The holiday mode empties the Header Tank and then refills with mains water. The holiday button needs to be pressed a few hours in advance of leaving. Providing the Header Tank has had time to fill with mains water and providing the user flushes the toilets twice after pressing the holiday button, the toilet cisterns and bowls are filled with chlorinated water that stays fresh for however long the duration of the holiday. On return from holiday all toilets and washing machines will be available as normal and the system will then automatically revert to normal mode.

9) Mains Water Only Mode Once the mains water only button is pressed, the system selects mains water to fill the Header Tank. The existing water in the Header Tank is used as usual but is replenished with mains water. This method of operation continues until the normal button is selected. This mains water only feature is provided to enable the rain water to be conserved for garden use during a drought. The same pump submerged in the rain storage tank can still be used at that time provided that its output is equipped with a T joint feeding a tap or other garden outlet. Alternatively a second pump for garden use only can be installed in the rain storage tank.

10) In the event of power cut In the event of a mains electricity power cut, firstly, water in the Header Tank flows by gravity as required until it runs out. Secondly, thereafter, the mains water supply valve can be manually opened and the tank will fill with mains water until the conventional ball cock closes; see Manual mains water *S..

: bypass below. This valve will require closing after the power is restored, ***. * S * S..

11) Time Limit Flow Mode -upper sensor failure *SS* In the unlikely event of a failure of the UPPER float sensor in the S..

* Header Tank, the Controller tries to fill the Header Tank, establishes that the upper sensor has not given a "full" signal, and "times out". The Mains water S...

not working light illuminates. The invention then switches to its back up program which fills the tank according to the flow time stored in memory.

Please also read the note on Set-Up mode above. The warning light indicates that the sensor most likely needs changing (unless both rain and mains water had run out).

12) Manual mains water bypass -lower sensor failure In the unlikely event of a failure of the LOWER float sensor in the Header Tank, the Invention would not know that the tank is empty. No indicator light would show but the user would become aware that water is not available at the appliances fed with rainwater.

To reinstate water supply, the user removes the Controller cover, selects the left hand manual (non electric) valve and turns it 90 degrees to open the mains flow. Electric power to the other valves is 12 volt only so there is no risk of electric shock. Mains water flows into the Header Tank until the ball cock valve turns the flow off. This safety feature works even if there is no electric power to the system.

13) Safety Features The invention has several inbuilt safety features: Float Sensor: The upper float switch in the Header Tank is the first barrier to flooding. It turns off the rain or mains water supply when the Header Tank is full.

Time Limit Flow control: Should the upper sensor fail, the Controller uses time limit flow control. The timing values used are those calibrated for this particular system during set-up. See (5) and (11) above. *** S * * *. .

s..' 20 Ball Cock Valve: This valve limits the mains water level in the Header Tank even if there is a power cut.

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Overflow Tower: A 4" (100 mm) diameter drain is designed to absorb the * combined flow of both the rain and mains water feeds if they were left on by the unlikely event of significant equipment failure. The large diameter overflow tower provides the head and the impulsion to ensure high volume flow through the overflow pipe, thus reducing to a minimum the risk of any overflow over the top edges of the tank itself into the roof space. With this feature in place, all the water delivered to the Header Tank harmlessly flows out of the building, into the guttering and back in to the rainwater tank.

14) Options Electrically-switched pump. The description above refers to a pressure sensitive pump in the rainwater storage tank which maintains rainwater pressure to the Controller. As an option, the invention can be equipped with a submersible pump in the rainwater storage tank which is electrically switched by the Controller. This permits a cheaper pump and uses even less electricity (as pressure is not maintained in the pipe to the Controller; the option pump only switches on when water is needed.

Solar powered pump and Controller. The description above refers to 220 Volt AC power for the pump and for the controller (converted to 12 Volt DC for the Controller). As an option, the invention can be equipped with a 12 volt or 24 volt electrically switched pump run by photovoltaic cells on the roof of the building and accumulator batteries. The Controller would also run directly off the 12 Volt DC supply. In this way the entire system and circulation of rainwater around the building can be assured without any use of mains electricity and costs can be further cut. *...

End of description * d.. *S. *a.*

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-S SI.-. S. * S * *

IS Claim

Claims

What I claim is:- 1) First claim: Apparatus for optimising the collection and storage of rain falling onto a building by managing the supply of this rainwater for use around the building by a Header Tank equipped with level sensors and other features and by a multi-function Controller (with buttons, mode indicator lights, a microprocessor-board, programmed logic and solenoid valves), all this referred to below as the "intelligent water management system".S S *. S * as.
2) Intelligent water management system as claimed in claim I used in conjunction with a) an underground rainwater storage tank, and b) an electric pump in the storage tank, controlled by programmed and user-*S.controlled features of the Controller. S... * S S...
3) Intelligent water management system as claimed in claim 2 wherein the Controller allows all the water in the Header Tank to be used before refilling, which therefore reduces the amount, and cost, of electricity used (by avoiding frequent starting of the pump, accompanying surges in electricity used, and hunting of the pump), pump strain and pump wear.
4) Intelligent water management system as claimed in claim 3 wherein the water flows to the appliances from the Header Tank by gravity, reducing pump and electricity use between Header Tank fills, and reducing strain and wear in the ball cocks or inlet valves of the appliances served.
5) Intelligent water management system as claimed in claim 4 wherein an absence of rainwater in the underground storage tank is detected by the absence of a "tank full" signal from the Header Tank within a pre-established time period, and which then, by the programmed logic of the Controller, switches mains water feed to fill the Header Tank.
6) Intelligent water management system as claimed in claim 5 which continues to look for rainwater every time a "tank empty" signal is received from the Header Tank, even after the Header Tank has been once filled with mains water, such that the rainwater is always used as the primary source for refilling the Header Tank.
7) Intelligent water management system as claimed in claim 6 which indicates by lights on the Controller whether the system is filling with rainwater or mains water.
8) Intelligent water management system as claimed in claim 7 which provides a set-up or commissioning mode which automatically calibrates, after the installation of the system and once only, the flow timers and stores in memory the time it takes for the rain water to fill the tank and for the mains water to fill the tank, whereby at any time thereafter, if the top sensor fails, the tank fills with rain water (if available) or mains water according to the time intervals memorised, this calibration accounting for different-sized *...Header Tanks, different water pressures and other variables. S... * * ***. *. S S * S * S.
9) Intelligent water management system as claimed in claim 8 whose commissioning mode calibration is performed three times so that the average of the Header Tank fill times can be used for the time period memorised.
10) Intelligent water management system as claimed in claim 9 provided also with an "auto tank refresh" function by which if the water in the Header Tank is not used in a 3-day period, the refresh program automatically flushes out the system, emptying the Header Tank back into the underground tank, and refilling the header with fresh rainwater, the purpose of "auto tank refresh" being to prevent rainwater in the Header Tank (which in a roof space in summer could be at 20°C or higher) from getting discoloured and stale due to bacterial action as cool clear water from the underground tank (at about 5°C or less) is pumped into the header.
11) Intelligent water management system as claimed in claim 10 provided also with a "flush mode' which permits the user by a button press to refresh the rainwater in the header in the same way and for the same reasons as "auto tank refresh" in claim 10.
12) Intelligent water management system as claimed in claim 11 provided also with a "holiday mode" which permits the user by a button press which empties the Header Tank back to the storage tank and then refills with mains water which subsequently, providing the user flushes the toilets twice after pressing the "holiday" button, the toilet cisterns and bowls (not just the Header Tank) are filled with chlorinated water that stays fresh for however long the duration of the absence. S... a.. * . S... S. * * S.
13) Intelligent water management system as claimed in claim 12 provided with a uholiday mode" which also, at the end of the holiday or absence, automatically reverts to normal mode, that is, the supply of rainwater to the Header Tank in place of the mains water.
14) Intelligent water management system as claimed in claim 13 provided with a "mains water only" mode which permits the user by a button press to fill the Header Tank with mains water every time the "tank empty" signal is detected and until the "normal" button is selected, this "mains water only" feature being provided to enable the rain water to be conserved for garden use during a drought.
15)Intelligent water management system as claimed in claim 14 which provides two escalated means of provision of water to the appliances in the event of a power cut whereby firstly, water in the Header Tank flows by gravity as required until it runs out and whereby secondly, thereafter, the mains water supply valve can be manually opened by the user and the tank will fill with mains water by the mains pressure until the conventional ball cock closes.
16)lntelligent water management system as claimed in claim 15 with a fail-safe system such that in the unlikely event of a failure of the upper float sensor in the Header Tank the Controller tries to fill the Header Tank, establishes that the upper sensor has not given a "full" signal, and "times out" (displaying the "Mains water not working light") whereupon the Invention then switches to its back up program which fills the tank according to the flow time stored in memory. S... S... * . *. . * . S S.
17)Intelligent water management system as claimed in claim 16 with a fail-safe system such that in the unlikely event of a failure of the lower float sensor in the Header Tank, in which case the invention does not know that the tank is empty, then the user has the facility to open the manual (non electric) mains water valve to re-establish water supply until the sensor is repaired or replaced.
18) Intelligent water management system as claimed in claim 17 with a fail-safe system such that the mains water ball cock valve in the Header Tank limits the mains water level in the Header Tank even if there is a power cut, and prevents overflow.
19) Intelligent water management system as claimed in claim 18 equipped with an Overflow Tower, a 4" (100 mm) diameter drain designed to absorb the combined flow of both the rain and mains water feeds if they were left on by the unlikely event of significant equipment failure, whereby the large diameter overflow tower provides the head and the impulsion to ensure high volume flow through the overflow pipe, thus reducing to a minimum the risk of any overflow out of the A-B gap or over the top edges of the tank itself into the roof space.
20) Intelligent water management system as claimed in claim 19 in which, to provide the air gap required by U.K. building regulations for the purpose of eliminating the risk of contamination of mains water by rainwater, the mains water flows into the tank from above the surface of the water. * * S ** * S...
21) Intelligent water management system as claimed in claim 20 which, as an option, can be equipped with a submersible pump in the rainwater storage *.tank which is electrically switched by the Controller rather than the default option of a pressure-sensitive pump whose flow is controlled by the S...S..... rainwater solenoid valve. S* * S.
22) Intelligent water management system as claimed in claim 21 which, as an option, is equipped with a 12 volt or 24 volt electrically switched pump run by photovoltaic cells on the roof of the building and accumulator battery(ies) whereby the entire system and circulation of rainwater around the building can be assured without any use of mains electricity. * * * S. S S... * I * *e. ISS. S.. * S.. S... * S *5 * * SSAmendments to the claims have been filed as follows -15 Claim What I claim is:- 1) Apparatus for the purpose of collection and storage of rain water which falls onto a building and is collected in a water storage means, comprising a header tank arranged to receive water from said water storage means and to feed water to end use locations, level sensing means, water control valves and a controller for controlling the level of water in said header tank via said water control valves in dependence on outputs from said level sensing means.2) Apparatus as claimed in claim 1 including said water storage means, and said water storage means being an underground rainwater storage tank and an incorporated pump for pumping water to the header tank, said pump being arranged to be controlled by the controller.3) Apparatus as claimed in claim 1 or 2 in which the controller is arranged to allow all the water in the header tank to be used before refilling.*: 4) Apparatus as claimed in any one of claims 1 to 3 wherein said controller includes tf'. means for detecting an absence of rainwater in the water storage means and for S.,.switching mains water feed to fill the header tank in the continued absence of a * signal within a pre-established time period from the header tank indicating that the tank is full.25. 5) Apparatus as claimed in claim 4 in which the controller is arranged to continue to look for supply of rainwater from the water storage means even after the header tank has been supplied by the mains water feed.6) Apparatus as claimed in any preceding claim in which said controller includes a flow timer for measuring the time period for water to fill said header tank, a storage memory and programming means to provide a set-up mode calibration which stores said time period in said storage memory and uses the time period for determining a level at which the header tank is full.7) Apparatus as claimed in claim 6 in which said programming means is arranged to perform said set-up mode calibration a plurality of times and to average the time period memorised.8) Apparatus as claimed in 6 or 7 comprising an upper level sensor for sensing when the header tank is full, and said programming means is arranged to use said stored time period as a backup to protect against failure of said upper level sensor.9) Apparatus as claimed in any preceding claim in which said controller is arranged to detect the event of water in the header tank not being used for a pre-determined time period, and in that event to empty and refill the header tank with water in order to flush out the header tank.10) Apparatus as claimed in any of claim 1 to 9 comprising flushing switch means which is arranged on actuation to cause the controller to empty and refill the header tank with water in order to flush out the header tank. S...11) Apparatus according to any of claim 1 to 9 comprising holiday mode switch * ,a means which is arranged on actuation to cause said controller to empty the header tank to the water storage means and refill the header tank from a mains water supply S..so as to provide a supply of water to end use locations fed from said header tank.12) Apparatus as claimed in any preceding claim comprising mains water only *. switching means, which is arranged on actuation to cause the controller to empty the header tank to said water storage means and then to refill the header tank from mains water supply, and then to continue to supply the header tank from said mains water supply until de-actuation of said mains water only switching means.