WO2022265502A1

WO2022265502A1 - System for the distribution and retention of rain water

Info

Publication number: WO2022265502A1
Application number: PCT/NL2022/050334
Authority: WO
Inventors: John Wilfred Nico VAN DE WETERING
Original assignee: Blue Innovations B.V.
Priority date: 2021-06-15
Filing date: 2022-06-14
Publication date: 2022-12-22
Also published as: NL2028459B1; EP4355072A1

Abstract

The present invention relates to a system for the retention of rainwater collected on impervious building surfaces, comprising a water distribution and retention module comprising at least one feed unit positioned at the top of the module, for collecting run-off water, and configured to provide a water in-flow volume ranging from a first to a second water volume; at least one water flow-dependent static distribution means; at least one outlet section for collecting and distributing a portion of the water flow; and at least one water distribution conduit positioned horizontally to the flow pipe, and fluidly connected to the outlet section.

Description

System for the Distribution and Retention of Rain Water

FIELD OF THE INVENTION

The present invention relates to structural systems for the distribution and retention of rain water, from on impervious building surfaces. It further relates to a vertical water retention and greening structure affixed to a fagade of, or integrated into a building.

BACKGROUND OF THE INVENTION

Increasing population growth and urban densification have reduced availability of arable land. Surface run-off of rain water carried on impervious building surfaces such as roofs, fagades and balconies where provided with a downspout in apartment buildings, which would intrinsically be a highly valuable resource, is typically collected in classical rain pipes, and then transported through drainage and sewer pipes to a discharge point such as a water cleaning installation, canals, rivers and eventually the sea. Rain water, if treated separately from sewage, may typically be discharged to the environment with little or no treatment, or, where possible, collected and stored, for uses such as watering of plants, cooling or flushing of a toilet, neither of which requires a high quality of filtered water; or as a source of potable water after a relatively mild purification.

Most buildings have a drainage system to remove rainwater from the roof of the building. Typically, for a pitched roof, the drainage system includes an open gutter located along the edge of the roof inclined so as to direct collected water to a downpipe; one or more downpipes that channel the water to a drain linking to the sewer infrastructure.

Most urban areas only have combined sewer systems, and hence collect both sewage and rain water in the same piping system. Consequently, the rain water will be treated as sewage, adding to the total load on the sewage treatment facilities, and/or leading to flooding where and when the sewers are lacking capacity.

At the same time, air quality issues trouble cities through emissions of toxic or noxious gases and fine dust. Yet further, the microclimate in urban areas is often an issue due to the high heat retention, which requires copious amounts of energy to cool down and maintain buildings cool.

And last but not least, the areas of arable land lost are also no longer available for food production, which will inadvertently increase the pressure on the areas that are left, as well as transporting food products into the cities to feed the ever-increasing urban population. Accordingly, there clearly remains a need to optimize rainwater retention, and its use to provide water for plants, cooling and the like. It would therefore be an advantage to be able to provide a local rainwater drainage and storage system, which ideally can be installed on existing buildings or a building fagades.

Preferably, a rain water drainage system should be completely passive and not require active components such as pumps, sensors, and so on. Thus, it is a further object of the present invention to provide a local and modular rainwater drainage while contributing to the overall green appearance of cities, and in particular of building walls.

Different systems have been proposed, such as for instance CN105532287B1, WO 2018/161190 Al, CN109168741B1, KR20120005808A, as well as the systems disclosed in FR2912162A1 and CN111567265A1.

The system of FR2912162Alcomprises a rainwater collecting device, comprising a rainwater inlet, and a series of tank modules arranged on top of each other and in fluid communication with each other. Rainwater can be extracted from the lowest tank module rain. This system does not comprise a static distribution that distributes water depending on the rainwater flow, but simply fills the tank modules starting with the lowest tank module. This implies that water would need to be pumped upwardly once the water level drops in a given tank .

The system disclosed in CN111567265A1 comprises a central helical rainwater distribution, and tank modules arranged at the outside of the central distribution, having fill level dependent water inlets. The central distribution is set up to fill up tanks from top to bottom, as a valve closes a tank off once it is filled. However, there is no flow-dependent static distribution of the rainwater between the tank modules. A disadvantage of this system is that lower tanks only will get filled once the upper tanks close down inflow, resulting in an uneven distribution; here water would need to be transferred between tanks once the filling level of the lower tanks is too low.

Accordingly, there remains the need for a rainwater retention system that distributes the inflow of rainwater evenly over a series of tanks and other water retention means. This appears particularly relevant for the provision of uses that require essentially constant water distribution such as vertically-integrated, e.g. for vertically greened fagades. BRIEF SUMMARY OF THE INVENTION The present invention relates to a vertically-integrated rainwater retention system. The present system may advantageously be installed as a replacement or drop-in for existing rain water piping, while at the same time also offering the possibility to retain rain water on the fagade, allowing its use for plant growth and/or evaporative cooling, in particular during dry periods, thereby reducing building maintenance efforts by offering shade, air treatment, and evaporative cooling to building occupants, and enhancing the quality of the work and life environment of the building's occupants as well as the public. Also, the reduction of potable water for the greening of buildings has become not only an architectural trend, but a necessity.

Further embodiments are set out in the dependent claims. The present invention also relates to a process for the retention and distribution of rainwater for the growth of plants on a fagade, and also the use for reducing energy use, improving air quality and generally, improving the environment, such as improving natural and living environment by further integrating both, and/or restoring the natural balance in cities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates embodiments of a fagade with various embodiments of the present invention, together with the drainage according to the state of the art. Herein, multi- columnar systems according to the present invention in which the water use modules are arranged in vertical columns. From left to right (tubing and columns 1 to 6), there is shown a traditional rainwater pipe according to the state of the art (1), a spirally shaped water tubing (2) according to the invention, comprising a feed unit controlling the amount of water fed to the tubing, preferably by an overflow threshold; whereby the tubing is wound around an optional vertical structural member; the same tubing (2) with distribution zones indicated for water separation retention and preferably equal distribution to water reservoirs and plant growth modules; modular water retention and storage tank modules (4) incorporated into the plant growth modules (5), and the outside view of the column (6) with foliage and plants exposed to the outside of the column.

FIG. 2 illustrates a water flow pipe system (21) with groves for guidance of water when at lower flows (2A) and a spiral tubing comprising parallel groves all over the surface to allow for the formation of cyclones movements at high water flows (2B). Optionally, for incremental spread of water for changing discharges, a central gas relief tubing (2C) may be present in the centre for high flow situations. Figure 2D shows a top view, also showing a secondary flow zone or section visible for vertical discharge to a lower situated flow path and/or outlet towards a water reservoir.

FIG. 3 illustrates a removable distribution outlet section (31) in different views (A and B). In C, the apertures and fitting stops are shows, that form the outlet 24. Aligning grooves for the occurring waterflow are shown on top, and fins or ridges for discharging water flowing on the underside, with continuing flow velocity in a radial direction at the underside of the profile. The distribution outlet section is installed in line with the helical flow unit, and can be removed or replaced, and ideally, the water throughput can be adjusted.

FIG. 4 illustrates a greenwall (41) comprising the system of the invention. Herein, a lid (42), top module (43) , system (45) and outer shell (46) and plant growth module 47 are depicted. FIG. 5 shows a top feed unit (51), comprising a lid (52), a downspout (53), a reservoir (55), and a connection to the down flow pipe (56), as well as a flow control system that controls the amount of water to be in the optimum range system.

FIG. 6 depicts a spirally shaped insert (61) according to the invention, for use in a module. Herein, the groves (62) present in the surface from the static distribution means, controlling the amount of water that is overflowing, and then directed towards separate inlets, by an overflow threshold.

FIG. 7 depicts a preferred embodiment of the invention, showing the module in top view (7A), exploded view (7B), and assembled (7C).

FIG. 8 depicts a spirally shaped insert (81), showing the tapping points for distribution of 1/3 of the water (82), ½ of the water (83) and all of the remainder or 1/1, (84).

FIG. 9 depicts three different embodiments for the use of spirally shaped inserts, namely 9A: 3 equal flow channels on a single helix, representing 3 equal distribution points (91); 9B: two helices intertwined and yielding 3x3 = 9 equal distribution flows over the same height (92); and 9C: 3 intertwined helices, yielding 3x3x3 = 27 tapping points for distribution of the water at over the same height (93); both in side and top view, respectively.

Detailed Description of the Invention

The above need and the above object together with numerous other needs and objects, which will be evident from the below detailed description, are according to a first aspect of the present invention obtained by a system for the retention of rainwater collected on impervious building surfaces , comprising a water distribution and retention module comprising i. at least one feed unit positioned at the top of the module, for collecting run-off water, and configured to provide a water in-flow volume ranging from a first to a second water volume; ii. at least one water flow-dependent static distribution means; iii. at least one outlet section for collecting and distributing a portion of the water flow; and iv. at least one water distribution conduit positioned horizontally to the flow pipe, and fluidly connected to the outlet section. According to a further embodiment of the first aspect, the system further comprises an outer shell enclosing the at least one flow- dependent static distribution means. Preferably, this comprises a curved flow plane in the shape of a helix, which may be positioned in an essentially tubular sleeve.

The present system comprises at least one top unit which collect occurring run-off water and by means of overflow introduces a starting point for the spiral flow which will be essentially constant, e.g. having a constant velocity and spread, below this unit.

According to a further embodiment of the first aspect, the flow-dependent static distribution means comprises an essentially helically shaped liner comprising optional protrusions and/or indentations to form fluid flow channels, to allow for different discharges and water volumes and/or flows. This advantageously provides for a curved flow path with profiling, by which a water film under commonly occuring flow rates forms, and wets from the inside out. The film then , depending on the water flow volume and velocity, will fill up the channel profiles until it surpasses the height of a profile. Shape ad static distribution means thereby result in a vortex with a constant flow rate throughout the entire discharge process, which allows to distribute the water in line with the distribution defined by the model.

The at least one water flow-dependent static distribution means may therefor form an inner liner section or unit, which may be preferably enclosed by an outer sleeve. Preferably, the outer diameter of the liner may conform to an essentially cylindrical shape, and may have a cross section that forms at least two trough shapes as seen in the water flow direction, wherein the liner is oriented such that the opening of the trough-shaped cross section receives the water flow in a radial direction with respect to the axis of rotation.

A lower wall of the opening of the trough then may comprise a second guiding surface, and an upper wall of the trough opposite to the lower wall may comprises a second guide surface for guiding the water flow along the guiding surface when water flows down the liner. The volume of water that flows down this path then essentially determines in which trough the water is directed downwardly, whereby the centrifugal forces push the water film toward the guiding outer walls, and if the level of water is high enough, over the wall and into the next trough. By this means, the water volume and the guides in the liner act as a static distribution means, distributing the water between the different channels.

Alternatively, the guide surfaces may also be formed by at least a flange or ridge disposed coaxially with the flow direction, wherein each flange or ridge is adapted to corresponds to retain a given water flow. Either configuration has the advantage of simple manufacture, and well- defined distribution, solely depending on the rainwater volume.

While there is no limitation to the number of channels or distribution means, these advantageously correspond to the inlets and outlets, and are in line with the water debits that may occur at the location, e.g. a large channel or trough for strong water volumes that may occur seasonally, and smaller channels or throughs corresponding to the volumes of drier seasons. A particularly preferred embodiment of the present liner comprises three different channels.

According to yet a further embodiment of the first aspect, the system comprises an in-line distribution means comprising a conduit having an inlet section for receiving the fluid stream, an outlet section for transporting the separated off water portion, and a swirl section for inducing a swirling motion to the fluid stream as the stream flows from the inlet section to the outlet section, wherein the swirl section has an interior space formed as an open passageway of helical shape.

The size of the swirl is dimensioned and configured to distribute a water film, and shaped such that varying flow rates ranging from 0.01 to 2200 litres per hour, i.e. the flows usually occurring with rainwater drainage are distributed at constant velocity. Preferably, the size of the swirl is dimensioned and configured this flow rates are varying of from 0.1 to 1100 litres per hour, more preferably of from 1 to 600 litres per hour.

According to a further embodiment of the first aspect, the passageway is formed by a central portion of the interior space of a helical shape. Preferably, the passageway has a central longitudinal axis extending substantially straight from the inlet section to the outlet section. More preferably, the passageway is of substantially uniform cross sectional size along the length thereof.

According to a further embodiment of the first aspect, the outlet section includes a portion of the helical swirl section has a wall provided with a plurality of apertures for discharging at least part of the fluid phase into the annular space, and wherein the outlet section comprises a water collector positioned below and in fluid communication with the annular space, and extending essentially perpendicular to the water flow pipe.

According to a further embodiment of the first aspect, the passageway is of substantially uniform cross sectional size along the length thereof.

Preferably, the outlet section includes a portion of the helical swirl section has a wall provided with a plurality of apertures for discharging at least part of the fluid phase into the annular space, and wherein the outlet section comprises a water collector positioned below and in fluid communication with the annular space, and extending essentially perpendicular to the water flow pipe.

According to a further embodiment of the first aspect, the swirl section is positioned in the lumen of the water flow pipe, and comprises a portion wherein a centreline of the portion follows a substantially helical path having an axis of helical rotation, wherein the amplitude of the helix is less than or equal to one half of the internal diameter of the lumen.

Preferably, the apertures are positioned along a longitudinal axis which radially traverses the swirl section along the length of the helical axis so that apertures are oriented in a common direction relative to the axis. According to a further embodiment of the first aspect, the system further comprises at least one stop or obstacle for adjustably and sealably inserting into an aperture in the discharging section.

In a preferred example, the amplitude of the helix may be chosen at 240 mm, yielding a tube diameter of 104 mm, and a cavity of 40 mm, being the hollow space in the centre of the tube, such that any solids caught in the flows may have space to be discharged without getting trapped. Such a module will easily fit into an existing standardized rainwater system.

Generally, the amplitude and height of the helix defines the flow speed, and may be suitably adapted for the number of levels, as well as the flow and overall height. Outflow areas or guides towards a retention module also preferably have suitable downward angle to ensure that the water flows away from the central distribution unit. In this respect "horizontal" implies that there is a suitable flow angle from the rainwater distribution to any tank, and onward to the various uses. Advantageously, any outflow may itself be separated into different flows, allowing for secondary and tertiary outflow profiles that can be adjusted in shape for greater accuracy spread for lower or higher flow rates. According to a further embodiment of the first aspect, the system further comprises at least one of: a. a water tank module for receiving the distributed rain water, optionally comprising an overflow arrangement for discharging rain water therefrom; b. a plant holding and growth compartment having a closed off bottom and an open top, the holding compartment defining a space for receiving soil including one or more plants, further comprising a drainage opening for discharging rain water therefrom; c. a water evaporation cooling unit; d. a grey water use member; and e. a conduit connecting the water tank and the plant holding compartment and/or evaporation cooling unit, for transporting rain water from the water tank module.

According to a further embodiment of the first aspect, the water flow pipe has an essentially circular cross-section, and wherein the swirl section is arranged inside the lumen of the water flow pipe; or wherein the water flow pipe has a substantially helical configuration wound around a central support member.

Advantageously, the present system may be used as an add-on system for existing buildings, as well as for new constructions with which, on the basis of a water balance for a building, a desired amount of square meterage of plants can grow autonomously, and without requiring drinking water during dry periods. Herein, each rain shower fills up the different reservoirs to a certain level, and so even in dry periods, a minimal constant level is maintained, equating to a "vertical water table" in the building envelope, and allowing for a water balance at building level at the fagade.

Preferably, the water pipe and/or swirl section are configured such that the fluid flow is channelled into a swirling motion when in in contact with the inner surface of the water pipe and/or swirl section.

According to a further embodiment of the first aspect, the inner surface comprises protrusions and indentations, preferably ridges and groves forming a multitude of channels inducing water flow, and directing the fluid flow depending on the amount of water and fluid velocity.

Instead of using the swirl tube of helical shape described hereinbefore, the swirl section may be formed of a tubular conduit provided with a helical swirl flow guide fixedly arranged in the tubular conduit, or around a central member. The shape of the curved flow plane may in general be helical and positioned in a tubular sleeve, yielding a curved flow path with profiling with which common flow rates form a water film that develops from the inside out and the profiles fills about the height of the profile. This results in a vortex with a constant flow rate throughout the entire discharge process. The system may preferably comprise an inflow opening at the top with which through an overflow principle water enters the system, and where varying flow rates result in a direct spread across the drainage profile and with which the gravity force de continuous distribution of the water film over the profiles reached after one, but preferably within two revolutions, defining the smallest module. Additionally, this may be supplemented with an additional inlet opening just below the height of the outlet opening to allow water to return from an already full reservoirs, and to be fed back into the drainage system, thereby balancing water flow continuity, distribution and speed, preferably over the entire course from top to bottom.

According to a second aspect, the present invention also relates to a method of collecting and distributing rainwater, comprising a. installing a system according to the invention to a downspout collecting rain water from an impervious surface of a building; and b. adjusting a multitude of discharging units debit to attain a static distribution of the rain water over a multitude of horizontal conduits at a given rain water flow, as specified for each occurring run-off situation (i.e. roof size, orientation, etc.).

According to a third aspect, the present invention also relates to a kit of parts comprising a unit for water collection at the top, and for distribution to the rain water flow pipe; a rain water flow pipe; a swirl section; a discharge section; and a horizontal collector member.

According to a fourth aspect, the present invention also relates to method for retrofitting an existing building, by removing a downspout system, and providing a system according to the present invention.

The present system may be fastened to the fagade of a building, e.g. a house, office building, storage facility, factory building, or incorporated into a building, optionally fastened to foundation of a building, together with other modules as disclosed herein, thus forming an assembly. The vertical and horizontal dimensions of the assembly may vary from a few meters to several tens of meters. The size of an individual module may vary depending on functionality, such as for instance for a greenwall, cooling, or the like. For a typical greenwall system based on capillary transport of water in substrates, useful dimensions are about 50 cm high, with a diameter of 45 cm by 30 cm., to allow for incorporation into typical rain water systems. Typically, the assembly comprises a top row of water collection module followed by the uppermost modules in which the upstream rainwater is initially collected. The rainwater then continues downstream to a module located below the upstream module. The rainwater typically flows from an upstream module to a downstream module located directly vertically below the upstream module, however, other configurations are feasible.

The rain water is collected typically from the roof top of a building, but alternative collection points may be contemplated. The rain water is collected upstream and led into the downspout connected to the uppermost module, by means of overflow introduced to the spiral flow thereby creating a constant flow for the whole height of the system.

The water tank of each module is typically sized for accommodating 5 to 45 litres , preferably at least 25 litres, of water per square meter of wall area, such as 6, 7, 8, or 9 litres per square meter wall area. Preferably, the water rank is dimensioned to foresee in the specific water requirement, e.g. for vertical greenery at 4l/m²/day, and for 30 dry days, a volume of 120 I/m² would be useful. In such case a module comprising a 60 to 120 I tank would be practicable.

The water collected in the water tank of the module may advantageously be transported to a vertical use, e.g. a toilet tank, a plant growth compartment or a evaporation cooler via a water feed line extending vertically from a water tank. Typically, this will done by water transfer system that makes use of capillary forces and/or water level control valves, to limit the water amount.

The water transported into e.g. plant holding compartment infuses into the soil and provides watering for the plants in the soil and the infused water in the soil not used by the plants will evaporate from the soil. The plants are typically green plants, e.g. grasses or mosses, or food crops and/or vegetables, giving the system a green wall appearance, which also shades the building, and removes dust, fines and gases from the environment.

In order to prevent overflow of the storage tank or any of the other horizontal modules, both the water tank and the horizontal feed lines and optional plant growth compartment, e.g. Figure 2, showing an outlet and an overflow inlet on the opposite, or the like may comprise separate water discharge arrangements. The helical direction, or the positioning of the water outlet of the feed box is not important, as it may also be executed in either direction. Preferably, each module provides for two modes of discharging water from the module. The overflow arrangement discharges any excessive rain water to a water tank of a downstream module when the water tank is at full capacity. This constitutes a fast and reliable overflow prevention of the water tank and the risk of overflowing the local rainwater drainage is eliminated for all but the most severe rainfalls. By selecting the distribution at varying flow rates for modular buffering and use of rainwater in a building envelope, based on the expected water balance, it may also advantageously be possible to essentially disconnect buildings from sewer for rainwater.

The horizontal water modules may be continuously supplied with rainwater from a water tank via the horizontal feed line.

In order to avoid overflow of the plant holding compartment, a drainage opening may be positioned to discharge excessive water directly into a downstream compartment. It is evident that multiple drainage openings may exist for a single module in order to distribute the drainage evenly.

Preferably, the system modules are stacked on top of each other along an entire wall section from the roof to the grounds. The capacity of the intermediate water storage tanks may be designed such that the lowest water tank compartment is likely never fully saturated and that the delay between the upstream and downstream modules of the assembly is approximately bridging the statistically derived average time period between rainfall. This embodiment is particularly preferred for the use with buildings where all of the rain water is to be used, whereas for green walls, the capacity may advantageously be fully used. It is evident that any of the above described embodiments according to the first aspect may be used in the assembly according to the second aspect of the invention.

The above need and the above object together with numerous other needs and objects, which will be evident from the below detailed description, are according to a third aspect of the present invention obtained by a method of draining rainwater by using a green wall, the method comprising: providing a system according to the invention, and a green wall plant growth assembly, the green wall plant growth assembly comprising one or more plant holding compartments located adjacent to a water tank and having a closed off bottom and an open top, the plant holding compartment defining a space comprising soil and one or more plants, the closed off bottom defining a drainage opening, and a conduit extending between the water tank and the plant holding compartment; receiving rain water in the water tank of the first module, transporting rain water from the water tank into the plant holding compartment, and facilitating plant growth. The method according to this third aspect is preferably used together with any of the modules according to the first aspect and/or any assembly according to the second aspects.

Most modern buildings have a drainage system to remove rainwater from the roof of the building. Typically, for a pitched roof, a drainage system includes an open gutter located along the edge of the roof inclined so as to direct collected water to a downpipe. The downpipe can channel water to a subterranean drain linking to the drain infrastructure. An alternative to disposing rainwater down a drain is to collect and store the rainwater from the drainage system. The stored water can then be used for any desired purpose such for watering of plants and vegetables in a garden or flushing a toilet, neither of which requires a high quality of filtered water. Both the above methods of handling surface runoff are costly since they involve installing pipes and trenches for transporting water, and cannot remedy the scarcity of clean drinking water in general. Further, there is always a risk of overflowing the system. Thus, the current preference and need by most municipalities is to be able to infiltrate the runoff water in local rainwater drainage. Preferably, the present system can be expanded, as set out in FIG.l, with additional water collection modules on the ground level, or subterranean, such as crawl spaces.

It is understood that local rainwater drainage is independent from any other runoff water system and thus, it is preferably designed and configured to cope with all rainwater from its connected surface area alone. Green roofs have been propagated as a solution, but constitute an investment which typically is out of sight for the public, and thus it may seem easier for many building constructors to simply use the existing runoff systems. Also, so called blue-green roofs, which combined water retention and greening can only be built on flat roof surfaces, and green roofs solely have little retention capacity and might need additional improvement of the roof supporting structure. However, the present system may also advantageously be combined with blue-green roofs.

It would therefore be an advantage to be able to provide a local rainwater drainage and storage system, that can be installed in view of the general public and which may contribute to a more attractive appearance of a building fagade. In this respect, drainage, distribution and storage of rainwater from roofs of buildings may be employed for adiabatic evaporative cooling on the facades of buildings in the fight against heat island formation, thereby providing passive cooling, in particular the system has better cooling effects at street level for occurring heat islands in cities during drought and heat stress. This is now at least in part resolved by the present system, which provides for a completely passive, modular add-on system, allowing greening of facades, connection to water reservoir storage such that comprises e.g. a capillary water supply, water delivery through water tanks. This also allows to use modular, prefabricated fagade sections in which water is stored for thermal resistance building envelope, and simple construction due to stacking of profiles to ensure regular distribution across multiple outlets. as the water films fills the profiles up to the static distribution means.

The system according to the invention preferably comprises (a) a plurality of modules structurally configured for growing plants therein; (b) a water distribution system comprising a water supply tubing further comprising static water retention valves.

In a preferred embodiment comprising 3 stacked storeys, in operation water is evenly distributed over 3 outlets, receiving 1/3, 1/2, 1/1 of the passing flow downward. In more complex systems, with more storeys or layers, the stacking of suitable profiles and distribution over these profiles increases the number of distribution points, and continuous spread and flow rate, and with it regular a regular distribution of a water film dependent on water flow rates, wherein each flow rate yields a specific flow path.

The water distribution system provides a flow of irrigation water to the plants growing in the plant growth modules, and drainage of excess water from the plant growth modules. The spacing between the plant growth modules in the suspension system is adjustable to optimize the amount of light passing through the greenwall.

That is, the plant growth module suspension system may be configured to allow natural lighting to pass to the plants growing in the plant growth modules. The present invention provides for a novel type of rainwater drainage that enables greening of parts of a fagade within the living and urban environment possible in a simple and affordable way, and which exclusively uses rainwater that is drained from roofs or similar surfaces, by creating a balance between a specific water harvest from a typical roof and a total plant surface which can be properly watered with this amount. The system dimensions may advantageously be planned in line with the predicted climate conditions. The system, when operated, allows buffering of rainwater at specified locations on the facade, after which it can be led to substrates / plant roots with capillary materials or the like. The system has the advantage of being reliable and showing a low-maintenance, due to self-cleaning, by offering a modular and passive water distribution system in combination with storage reservoirs and green fagade elements, which can replace existing and new rainwater piping.

The present system permits to establish a predictable and controllable water distribution over the height of rainwater along the facades of buildings over several storage reservoirs, regardless of drainage intensity or duration of precipitation events, whereby each storage reservoir may be filled evenly at every occurring situation.

Advantageously, the system may replace traditional downspouts; and provides a statically controlled distribution run-off water over retention modules on building facades, or in building envelopes, such as balconies, floors, facades and others. It preferably may also comprise one or more retention modules at ground level; and can in generally be connected to the building infrastructure.

The main flow pipe may induce a spiral flow due to provision of a spirally shaped vertical drainpipe, prefearbly which an internal profiling, in combination with dimensioning may create an essentially continuous flow speed, and therefore position and spread of any occuring water flow.

The distribution may advantageously be achieved by placing a outlet means which, in the path of the water stream, separates this stream into a passing and continuous water stream, as a static element, using preferably the Coanda principle as already applied in so- called water screens in rivers, whereby the continuous water flow improves the cleaning of the screen and the chance of survival of fish.

The system also may be used for horticulture, for instance vertical farming, and incorporated into other run-off "grey water" applications. Application of the invention preferably also delays rainwater drainage to the sewer system, thereby reducing peak load on the sewer system.

Additionally, drainage, distribution and storage of rainwater from roofs of buildings may be employed for the conservation of plants, fruits and vegetables in a vertical growth medium (substrate) over the height of the drainage path throughout the year. In the event of exceptionally persistent drought, water can easily be entered into the system at ground level, by pumping it up, after which it is again predictably discharged and distributed, as is the case for rainwater. Advantageously, a water stand- or rising pipe may be incorporated in the present system, preferably in the centre of the helical sections.

Finally, drainage, distribution and storage of rainwater from roofs of buildings may be employed for adiabatic evaporative cooling on the facades of buildings in the fight against heat island formation, thereby providing passive cooling.

In operation, the width distribution, and the height / thickness of the water film over the width, are preferably dimensioned such that a constant flow rate of the downstream water flow may be achieved. When a high flow is encountered, the spiral shape and groves of the channels reach a constant end flow rate, such that the distribution, in width and height / thickness, of the water film becomes less turbulent and/or laminar, allowing positioning of any dirt particles in the water stream to become manageable, as the system becomes self-cleaning with a substantial rinse.

The plant growth modules in the vertical growing system may be structurally configured for growing plants using any convenient method. For example, the plant growth modules may be configured for growing plants hydroponically, such as via a nutrient film technique.

The rain water distribution is typically fed by rain water that is collected in roof structures, and fed to the water distribution tubing of the system below, but may also include other "grey water" sources.

The water distribution system may advantageously be configured to provide water to a first inlet of an upper plant growth module, and to further lower inlets in the flow path. The system is in particular able to provide for a constant water load over the whole system, thereby providing for a continuous water provision.

Active or passive static valves may be present at each of the intersections with the plant growth modules that allow for purging of the system, e.g. to remove contaminated water as usually at the end of a longer period without rain, which is likely going to be contaminated, and then can be switched to a distribution per plant growth module or horizontal line in line with the desired distribution.

The system may be structurally configured for assembly in any kind of building or to any portion of a building. In one embodiment, the present invention may be configured for installation to a building fagade. The system may in particular be installed or mounted to the outside of an existing building fagade, for instance as a retrofit. The system may be conveniently structured as modules, and any number of modules can be installed in a building; e.g. and pre-configured with a limited amount of distribution modules or adjusted afterwards by changing the configuration.

In summer, the system may provide shade the interior and exterior of the building, and reduce solar heat gain by absorbing energy as latent heat, through transpiration or adiabatic evaporation. As such, the system helps to mitigate the urban heat island effect like a green roof. In winter, it may provide additional insulation and protection to the fagade.

The vertical rainwater distribution tubes preferably have a spiral shape, or comprise a helical member. The vertical rainwater distribution tubes preferably also comprise indentations or groves on the interior side facing the lumen, to channel water at lower concentrations along the groves.

When combining to spiral shape and groves, the water will likely travel in cyclone route, and hence there is more throughput possible due to the retained gas path through the centre of the tubing, to avoid clogging and plug flow. This leads to a higher capacity and reduces clogging and otherwise issue with presently employed simple rainwater pipes.

Yet further, by having a predicted flow along the groves, a static distribution can be incorporated towards the plant growth modules or distribution pipes feeding the planting plant growth module. Baffling in the tubing can be used for water containment and channelling to avoid exposing the chain to water flows, and to realize a Coanda effect over the baffle.

In this embodiment, water can be supplied and distributed to all plant growth modules simultaneously through gravity combined with the Coanda flow effect.

The system can be installed in a frame, cage, or similar support structure to provide strength. For example, a frame can be built of aluminium, stainless steel, wood, fiberglass, plastics, or other materials, and the plant growth module suspension system can be mounted to the sides, top, and/or bottom of the frame.

The present system may be installed in the form of independent blocks or modules. Each block may have its own vertical water supply system. Each block further may comprise several sections of pipe, the swirl sections, distributions sections, and horizontal distribution conduits. The swirl sections, distributions sections may be formed integrally with the water flow pipe, or may be formed as separate inserts that are affixed in the pipe.

The swirl sections, distributions sections may be formed from any suitable materials, preferably such as those usually employed for rain water pipes, e.g. PVC, Polypropylene or other suitable polymers. Any useful method may be applied for the manufacture, such as (co)extrusion, calendaring, but also additive formation including 3D printing.

The sections according to the invention may advantageously be prepared from metal or metal alloys, or combinations of metal alloys and polymeric materials. These include zinc copper, aluminium, iron, magnesium, alloys thereof. Also useful are metals that are passivated by e.g. anodization, protective coatings, or addition of galvanic cathodic protection, such as galvanic anodes.

As a non-limiting example, the swirl section may advantageously be prepared by bending or rolling a metal strip to include essentially parallel ridges or channels that form the static distribution means, and subsequently forming the obtained shaped strips into a helical shape, prefearbly a shape that fits into a pipe outer section acting as an essentially cylindrical sleeve for the swirl section, whereby the outer diameter of the helix may essentially correspond to the inner diameter of the sleeve.

There is no limitation on the height of the individual blocks or the width of the plant growth module suspension system in a particular column, and different modules in the same building may have the same or different heights or widths. Although there is no limitation on the height of the buildings, certain embodiments may be conveniently installed in modules which are shorter than a building height.

Numerous modifications and variations of embodiments of the present invention are possible in light of the above teachings, and therefore, within the scope of the appended claims, the invention may be practiced otherwise than as particularly described.

Detailed Description of the Drawings

FIG 1. Shows from left to right: traditional downspout (1, not according to the invention), the present flow principle illustrated (2), stacked modules according to the invention with top feed unit, water outlets and inlets (3), in case water reservoirs are completely filled, modules combined with modular water storage units (4), integration of water storage with a modular vertical green wall system (5), and a complete water storing fagade system (6) with passive water distribution and storage for use in green wall modules, and/or cooling, and/or greywater use). Each water flow line has a top feed unit (7) included, which is not visible from the outside in the systems comprising an external cladding or green wall.

FIG 2. shows a new downspout line: Herein, a new downspout is a modular tubing system (Fig. 2 A, 21) in which a number of helical shaped flow profiles (Fig. 2 B, 22) are positioned above each other. Each flow profile is the same with grooves for additional flow stability. Due to a constant flow velocity a random passing waterflow will result in a specific spread of this flow over a number of grooves (23) due to gravitational and centrifugal forces induced by the helical flow path. Partial distribution of a random flow of passing rainwater is organised over the used spirals first making use of a fixed number of water distribution inserts whereby a partial waterflow is diverted and led to an underlying spiral flow profile and ultimately outward into the water reservoirs from the 'lowest' helical section in the configuration. At the same height at the opposite side of the tube an inflow of excessive water in the water reservoirs when full can be re-introduced in the downspout towards distribution at lower levels, or ultimately the sewer.

Distribution of the passing waterflow is prefearbly developed by introducing apertures, by placing stops or obstacles into the grooves of the helical discharging section. The needed distribution characteristics are the result of the number of holes for sequential in each groove, the width of the holes, and the shape of the obstacle, whereby a self cleaning principle is developed by introducing a a effect in the spiral flow towards the holes, thus preventing debris in the run off of roofs eventually getting stuck in the holes. The inside of the tube may comprise: a) profiling above a helical section which provides extra flow capacity for occasional runoff events which exceeds the profile dimensions, and b) profiling of the tube walls to create friction in the passing spiral waterflow and therefore forcing the fluid flow towards the helix beneath by lowering its speed and centrifugal force.

The number of helically shaped flow profiles and static/passive distribution sections can be calculated from the number of required swirling unit, outlet or discharging units, and a maximum of water reservoirs by the following formula:

U = D⁽ⁿ⁾, wherein U equals total water reservoirs, D equals number of consecutive consistent partial flow configurations, for example (1/1, ½, 1/3, etc); and n equals number of flow- inducing profiles. A front portion of the enclosure of this embodiment may be sealingly removeable or pivotable for maintenance purposes of the system and upgrade of components for example by adjusting or changing water distribution inserts.

Figure 4 shows flow and distribution configuration: The developed waterflow and distribution technique can be configured to adjust to specific circumstances, whereby an increase in the number of used flow spirals and typical distribution inserts defines the total of water outlets in a single downspout system. For illustration a configuration may be created which comprises three identical helical flow path units and three different types of distribution zones or outlets, each creating a consistent partial flow of 1/3, 1/2 and 1/1 of the total passing waterflow.

From the downspout gutter, runoff water is introduced by a top feed unit into the helical flow system. After two complete helical turns a continual fluid flow has been induced and the spread of the passing waterflow is directed into channels defined by protrusions and indentations, i.e. ridges and grooves, which allow the fluid flow to be first divided by 2/3 of the flow volume continuing downwards, and 1/3 passing to a lower level helix spiral (II). This partial flow can then again be divided after two complete spiralling turns towards the lowest helical flow path which then can divide this partial flow towards outlets in the tubing system into water reservoirs. A first 1/3 of the water is thereby diverted into the space between the spiral and tube and led outside by gravity and centrifugal forces, then again after two spiral turns 1/2 of the water is diverted accordingly and lead to the outside, after which a complete disruption in the spiral flow path diverts the resulting leftover of the flow in the space between the spiral and the tube leading it toward a lower outlet, thus providing the needed space and pathlength for the next diversion of a partial flow from the spiral above (II) which then again can be separated into equal amounts again for the next module.

The helical sections according to the invention provide a spiral flow path supported in the water flow pipe, with a central axis substantially vertically. The sections are adapted to receive at an upper end thereof a water flow from the top feed unit. This spiral flow path may include a plurality of helical turns wherein each turn includes an inner portion and an outer portion with the outer portion being inclined upwardly relative to the inner portion.

The spiral is further characterized in that the inner portion includes at least a first part and a second part, wherein the second part is prefearbly inclined upwardly relative to the first part at a steeper angle to horizontal than the first part throughout part of the length of the spiral separator, such that generally non-turbulent or laminar flow of water is achieved along the part of the length of the spiral flow path, and turbulent or still water areas are inhibited. Typically, a flowing water film distributes itself at even thickness over a profile, although some shapes were found to induce a different distribution of the water flow, although this is not desired.

Figure 3 shows flow and distribution configuration: The developed waterflow and distribution technique can be configured to adjust to specific circumstances, whereby an increase in the number of used flow spirals and typical distribution inserts defines the total of water outlets in a single downspout system. For illustration a configuration is explained herein which comprises three identical helical flow path units and three different types of distribution zones or outlets, each creating a consistent partial flow of 1/3, 1/2 and 1/1 of the total passing waterflow.

FIG 4. shows a green wall system: This figure illustrates an integration of the downspout system according to the present invention with a modular green wall system consisting of modular water storage units, each with zones for passive water flow from the water storage towards plant roots, grasses, mosses or vegetables in hydroponically substrates or without, which may be planted in removable frames. A top unit (the 'first module') comprises a water collector and can be combined with a fixed water reservoir which connects the system with the gutter and provides the runoff of rainwater. Once this first reservoir is filled, and by introducing a minimal vertical height for introducing the constant spiral flow velocity in the system which then be evenly/ constant distributed over the flow pipe, and the water reservoirs in the green wall system.

FIG. 5 shows a top feed unit (51), comprising a lid (52), a downspout (53), a reservoir (55), and a connection to the down flow pipe (56), as well as a flow control system that controls the amount of water to be in the optimum range system.

FIG. 7 depicts a preferred embodiment of the invention, showing the module in top view (7A), exploded view (7B), and assembled (7C). This includes sleeve (71), a wall fixture (72), internal distribution means in the shape of a helical insert (73); water outlet section (76) and water outlet (74) and connection (75) to the horizontal water use point.

FIG. 8 depicts a spirally shaped insert (81), showing the tapping points for distribution of 1/3 of the water (82), ½ of the water (83) and all of the remainder or 1/1, (84). This ensures an equal distribution over the entire height, wherein each of the three outlets receives an essentially equal mount of water.

FIG. 9 depicts three different embodiments for the use of spirally shaped inserts, namely 9A: 3 equal flow channels on a single helix, representing 3 equal distribution points (91); 9B: two helices intertwined and yielding 3x3 = 9 equal distribution flows over the same height (92); and 9C: 3 intertwined helices, yielding 3x3x3 = 27 tapping points for distribution of the water at over the same height (93); both in side and top view, respectively. This shows that at a given height, an externally identically dimensioned module can give a multitude of different water outlets, and thus serve for modular planning, using the same internals. The drawings and the corresponding description are only intended to illustrate the invention. The details of the water system according to the invention may vary considerably within the scope of the claims. It is apparent that the idea of the invention may also be applied to other objects than rain water retention systems, such as grey water retention and distribution systems.

Claims

1. A system for the retention of rainwater collected on impervious building surfaces, comprising a water distribution and retention module comprising i. at least one feed unit positioned at the top of the module, for collecting run-off water and configured to provide a water in-flow volume ranging from a first to a second water volume; ii. at least one water flow-dependent static distribution means; iii. at least one outlet section for collecting and distributing a portion of the water flow; and iv. at least one water distribution conduit positioned horizontally to the flow pipe, and fluidly connected to the outlet section.

2. The system according to claim 1, further comprising an outer shell enclosing the at least one flow-dependent static distribution means and the at least one outlet section.

3. The system according to claim 1 or claim 2, wherein the flow-dependent static distribution means comprises an essentially helically shaped liner comprising optional protrusions and/or indentations to form fluid flow channels .

4. The system according to claim 3, wherein the at least one flow-dependent static distribution means comprises a swirl section for inducing a swirling motion to the fluid stream as the stream flows from the inlet section to the outlet section, wherein the swirl section has an interior space formed as an open passageway of helical shape.

5. The system according to any one of claims 1 to 4, wherein the in-line outlet and distribution section comprises a conduit having an inlet section for receiving the fluid stream, an outlet section for transporting the sepa rated-off fluid portion.

6. The system according to claim 5, wherein the passageway is formed by a central portion of the interior space of the helical shape.

7. The system according to claim 6, wherein the passageway has a central longitudinal axis extending substantially straight from the inlet section to the outlet section.

8. The system according to any one of claims 5 to 7, wherein the passageway is of substantially uniform cross sectional size along the length thereof.

9. The system according to any one of claims 1 to 7, wherein the outlet section includes a portion of the helical swirl section having a wall provided with a plurality of apertures for discharging at least part of the fluid phase into the annular space, and wherein the outlet section comprises a water collector positioned below and in fluid communication with the annular space, and extending essentially perpendicular to the water flow pipe.

10. The system according to claim 9, wherein the outlet section further comprises a member, preferably in the form or a protrusion of ridge profile, for directing the water film wetting the downward facing surface discharge outwardly toward the flow pipe wall.

11. The system according to any one of claims 1 to 10, wherein the swirl section is positioned in the lumen of the water flow pipe, and comprises a portion wherein a centreline of the portion follows a substantially helical path having an axis of helical rotation, wherein the amplitude of the helix is less than or equal to one half of the internal diameter of the lumen.

12. The system according to claim 10, wherein the apertures are positioned along a longitudinal axis which radially traverses the swirl section along the length of the helical axis so that apertures are oriented in a common direction relative to the axis.

13. The system according to any one of claims 8 to 10, further comprising at least one stop or obstacle for adjustably and sealably inserting into an aperture in the discharging section, thereby defining the maximum throughput thereof, as well as generating draft in the fluid flow.

14. The system according to any one of the previous claims, further comprising at least one of: a. a water tank module for receiving the distributed rain water, optionally comprising an overflow arrangement for discharging rain water therefrom; b. a plant holding and growth compartment having a closed off bottom and an open top, the holding compartment defining a space for receiving soil including one or more plants, further comprising a drainage opening for discharging rain water therefrom; c. a water evaporation cooling unit; d. a grey water use member; and e. a conduit connecting the water tank and the plant holding compartment and/or evaporation cooling unit, for transporting rain water from the water tank module.

15. The system according to any one of the preceding claims, wherein the water flow pipe has an essentially circular cross-section, and wherein the swirl section is arranged inside the lumen of the water flow pipe; or wherein the water flow pipe has a substantially helical configuration wound around a central support member.

16. The system according to any one of the preceding claims, wherein the water pipe and/or swirl section are configured such that the fluid flow is channelled into a swirling motion when in in contact with the inner surface of the water pipe and/or swirl section.

17. The system according to claim 14, wherein the inner surface comprises protrusions and indentations forming a multitude of channels inducing water flow, and directing the fluid flow depending on the amount of water and fluid velocity; and wherein the surface of the water flow pipe comprises a pattern induce friction and to slow down the flow.

18. A greenwall system, comprising an outer shell formed by consecutive plant holding and growth compartments, the shell enclosing the system according to any one of claims 1 to 17.

19. A method of collecting and distributing rain water, comprising a. installing a system according to any one of claims 1 to 15 to a downspout collecting rain water form an impervious surface of a building; and b. adjusting a multitude of discharging units debit to attain a static distribution of the rain water over a multitude of horizontal conduits at a given rain water flow.

20. A method for retrofitting an existing building structure, comprising removing the existing rain water downspout with a system according to any one of claims 1 to 17, or a greenwall according to claim 18.

21. A kit of parts comprising at least one feed unit positioned at the top of the module, at least one rain water flow pipe; at least one swirl section; at least one discharge section; and at least one horizontal collector member.

22. A water feed unit for positioning at the top of the module according to any one of claims 1 to 18.

23. A rain water flow pipe configured for the module according to any one of claims 1 to 18.

24. A swirl section configured for the module according to any one of claims 1 to 18, preferably formed as an insert into an outer sleeve.

25. A discharge section configured for the module according to any one of claims 1 to

18.

26. A horizontal collector member configured for the module according to any one of claims 1 to 18.