Patent Application
20200095770
Stormwater, or water that originates during precipitation events, is a resource and its appropriate management is particularly desirable given that the world's population continues to grow, and accordingly requires an increased amount of water. A consideration in the design and construction of residential, commercial and other structures relates to the rooftop or other urban surfaces, and particularly to the management of stormwater that contacts the rooftop or other urban surfaces. While it may be desirable for stormwater to be captured and ultimately used, large volumes of untreated stormwater are known to run off rooftops or other urban surfaces, often through sewage systems, and into rivers, streams or other sources of water that may serve as drinking water or other water consumed or otherwise used by humans. Use of such water can lead to increased health risks and other undesirable hazards and environmental problems. Stormwater runoff also is a particular problem in many urban areas because of the increase in impervious area as the density of building and paved area increases. Further, flooding from stormwater runoff may lead to damages in infrastructures such as buildings, roadways and bridges.
Further, in high precipitation events, sewer systems or drainage systems in many urban areas cannot effectively handle the amount of water, which causes flooding that could lead to significant damage to urban infrastructure plus issues in sewage management, such as combined sewage overflow, and could lead to water that is ineffectively treated for user consumption or otherwise lead to contaminated water to enter a river or other waterway.
One type of roofing system provided to appropriately capture rooftop stormwater is known as a blue roof. A blue roof is a roof design that is explicitly intended to store water. Blue roofs can be created by temporarily ponding water on the roofs through devices that may actively or passively regulate the drainage of the water from the roof, such as weirs and control flow drains. Blue roofs allow for a regulated runoff of stormwater from the roof, thus preventing a downstream stormwater infrastructure from surcharging.
In blue roofs, ponding water will exert hydrostatic pressure on the roof, which could void the warranty of roofing membrane manufacturers. Waterproofing thus can be required to adequately secure the roof structure and avoid leakage. Further, blue roofs often suffer from bacteria growth, foul smells, algae and provide breeding ground for mosquitos given the necessary standing water retained by the blue roof, leading to health concerns.
In some blue roofs, ponding water may be retained on trays that are placed on the roof, and such trays can be oriented so that, once the trays are full, the excess rainwater will overflow onto the roof membrane and flow to drains. However, even in such a situation, there exists exposed standing water and the hazards of bacteria growth, foul smells, algae and mosquitos discussed above.
Non-penetrating detention trays may be used, but have a complex installation, which may damage a roof membrane and cause a leak. The trays are exposed to ultraviolet rays and can become aged and brittle over time. Stones may also be used to avoid wind uplift, but this would lead to loss in water storage capacity. Blue trays also have an open water orientation, which will also have exposed standing water and the hazards of bacteria growth, foul smells, algae and mosquitos discussed above.
Another type of roofing system provided to regulate stormwater is known as a green roof. A green roof is a roof that is covered with vegetation and a growing medium that is planted over a waterproofing membrane. Green roofs have multiple layers that can include vegetation, a growing medium, and other components, but have a higher upfront cost with a complex installation and higher maintenance costs.
The present application provides for a design of a stormwater management system that is capable of effectively at least holding back and retaining stormwater runoff from a rooftop or other urban surface, can be usable with a variety of types of roofs or other areas of a building, and allows for a lightweight stormwater management system with little maintenance, but avoids some drawbacks of conventional stormwater management apparatuses. Further, a water retention amount can be improved with respect to known solutions, and a system that allows for a controlled release rate while still having desirable water retention can be achieved. A design that includes a water permeable and reflective top that allows rainwater penetration and reduces energy use is also within the scope of this application.
In embodiments, a stormwater management apparatus is described. The apparatus includes a composite having a water storage component and a drainage component provided below the water storage component, so as to allow for controlled flow of stormwater from the water storage component to the drainage component. The water storage component and drainage component are provided in a single unit.
In embodiments, a stormwater management apparatus is described. The apparatus includes a composite having a first protective component, a water storage component, and a drainage component provided below the first protective component, so as to allow for controlled flow of stormwater to the water storage component. The water storage component, first protective component and drainage component are provided in a single unit.
In embodiments, a method for managing stormwater runoff is described. The method includes assembling, as a single unit, a composite comprising a water storage component and a drainage component, the drainage component being provided at a position below the water storage component. The method further includes providing the composite on a new or previously urban surface.
In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it may be understood by those skilled in the art that the methods of the present disclosure may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
At the outset, it should be noted that in the development of any such actual embodiment, numerous implementation-specific decisions may be made to achieve the developer's specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. In addition, the composition used/disclosed herein can also comprise some components other than those cited. In the summary and this detailed description, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. The term about should be understood as any amount or range within 10% of the recited amount or range (for example, a range from about 1 to about 10 encompasses a range from 0.9 to 11). Also, in the summary and this detailed description, it should be understood that a range listed or described as being useful, suitable, or the like, is intended to include support for any conceivable sub-range within the range at least because every point within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each possible number along the continuum between about 1 and about 10. Furthermore, one or more of the data points in the present examples may be combined together, or may be combined with one of the data points in the specification to create a range, and thus include each possible value or number within this range. Thus, (1) even if numerous specific data points within the range are explicitly identified, (2) even if reference is made to a few specific data points within the range, or (3) even when no data points within the range are explicitly identified, it is to be understood (i) that the inventors appreciate and understand that any conceivable data point within the range is to be considered to have been specified, and (ii) that the inventors possessed knowledge of the entire range, each conceivable sub-range within the range, and each conceivable point within the range. Furthermore, the subject matter of this application illustratively disclosed herein suitably may be practiced in the absence of any element(s) that are not specifically disclosed herein.
The term “urban surface,” as used herein, may refer to a rooftop, a roadside, a sidewalk side, or any surface that may be found in an urban setting.
The water storage component 1, which may also be referred to as a fleece, may be a commercially available water retention fleece, such as XF 110 and/or XF 154 sold by Low and Bonar Inc. under the Xeroflor brand. XF 110 and XF 154 are needle-punch nonwovens having particular configurations, and include polyester and other content. Also, the water storage component may be in the form of recycled material or any material capable of providing a layer that can hold at least some amount of water for at least some amount of time above the drainage mat 2. Further, the water storage component 1 may include any high loft nonwoven material. The water storage component may be wholly or partially in the form of a mineral wool roll or mineral wool slab, as discussed with reference to other Figures, below.
The composite 5 including the water storage component 1 may have a water holding capacity of from about 20-150l/m2 (0.49-3.68 gal/sf) or from about 20-100l/m2 (0.49-2.45 gal/sf), or from about 20-75 l/m2 (0.49-1.84 gal/sf).
The water storage component 1 may have a high water retention to weight ratio. For example, the ratio of water retention to weight may be from about 70-97%, or about 80-95%, or from about 85-95%. One skilled in the art would recognize a water retention to weight ratio can be determined by a mass of water retained divided by the mass of the component (e.g., the water storage component 1) when fully saturated.
The water storage component 1 may have a thickness of about 0.2 to about 8, or about 1.25 to about 1.75, or about 1.5, inches. The thickness of the water storage component 1 may be at least 5 times more than, or at least 10 times more than, or at least 20 times more than the thickness of the drainage component 2.
Utilizing such a composite having the water storage component 1 and drainage component 2, there may be no open water to promote bacterial/algae growth, and mosquito breeding and foul smells are also avoidable.
The water storage component 1 may also act as a protective component, so as to protect the drainage component 2 from uncontrolled exposure to water. While in some embodiments, such as that in
In some embodiments, the drainage component 2 may be in the form of a commercially available drainage and filter mat, such as XF 108 sold by Low and Bonar Inc. under the Xeroflor brand. XF 108 and/or the drainage mat 2 may also have an entangled filament structure such as an entangled core that is comprised of thermally bonded polypropylene or any polymeric monofilaments. The filaments may be randomly entangled and formed in various patterns so as to provide a network of material forming the drainage component 2.
The drainage component may be a mat 2 may be formed of an elongate, indeterminate-length openwork mat (or web), of randomly convoluted polymeric filaments. The randomly convoluted polymeric filaments comprising mat 2 may be made of any thermoplastic material. In some embodiments, the thermoplastic material is able to withstand various temperatures. The thermoplastic material may be, for example, a polyester, polyolefin, or nylon. Exemplary materials for the thermoplastic material include polypropylene, nylon 6 (or polyamide 6), polylactic acid, polycaprolactone, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, vectran, high density polyethylene, and blends or copolymers thereof.
The randomly convoluted polymeric filaments may be intersecting filaments that form a three-dimensional mat. That is, the filaments may intersect each other at one or multiple points along each respective filament and bonded to each other at intersecting points. The filaments may have a diameter of 300 to 1000 microns, or 650 to 750 microns, or 500 to 600 microns.
The weight of the filaments comprising the mat 2 may be between 8 and 30 ounces per square yard (osy), or between 15 and 25 osy.
The polymer structure of the mat 2 may be formed by extrusion of the thermoplastic material at a temperature above the melting point of the material into or onto a structure or mold having a patterned configuration. As shown in
For example, the mat 2 may have a patterned configuration of three-dimensional structures 3 including waffle, pyramids, cones, cylinders, cubes and the like. In some embodiments, the structures 3 of the mat 2 may comprise a grid-like structure comprised of truncated cones or pyramids. The structures 3 may form a grid-like pattern where each column of structures 3 is spaced from each other along a first axis when viewed top-down or bottom-up. In some embodiments, the three-dimensional structures 3 may be arranged in a plurality of columns with bottoms of the three-dimensional structures 3 spaced from each other as seen from a the bottom-up front view of the mat 2 as seen in
A drainage rate (e.g., a flow rate) afforded by the mat 2 may be from 2-10 gal/min/ft at a 0.05 gradient, or from 2-8 gal/min/ft, or from 2-6 gal/min/ft at the same gradient.
The mat 2 may also have an air gap provided so as to avoid hydrostatic pressure on the roof membrane or a comparable urban surface. A thickness of such an air gap may be from about 6-51 mm (0.25-2 inches), or about 6-38 mm (0.25-1.5 inches), or about 6-25 mm (0.25-1 inches).
By way of example, a contemplated process for producing the mat 2 is to utilize a method where continuous molten thermoplastic monofilaments are extruded onto a three-dimensional profiled support structure or into a mold in overlapping rows of irregular loops which are self-bonded or fused at random points of intersection without using any bonding agent or reinforcing inserts. However, bonding agents or inserts may also be used. Additionally, while the above-described configuration, shown as a configuration in
The composite may be provided in roll or sheet form and installed onto a new or pre-existing roof in rows. The composite, and thus its constituent components, may have a flexibility sufficient to allow for its being provided in roll form.
Atop the uppermost component of the composite, which may be the water storage component, a filter fabric (described in further detail below), or one or more fleeces, may be a ballast layer (not shown in
The composite 5 may be provided in roll form and installed onto a new or pre-existing roof in rows. The composite, and thus its constituent components, may have a flexibility sufficient to allow for its being provided in roll form.
In one embodiment as shown in
Referring to
In the embodiment shown in
In some embodiments such as that shown in
In some embodiments, the water storage component 10 may be in the form of a mineral wool roll or a mineral roll slab. The mineral wool roll or mineral wool slab may comprise a mineral wool, a recycled nonwoven pad and/or a superabsorbent polymer (SAP) in powder, pellet and/or fiber form. The SAP may be able to absorb, retain and slowly release an amount of water up to 500 times by weight. In some embodiments, the water storage component 1 or water storage component 10 mineral wool roll or mineral wool slab may be capable of holding 0.5 inches or more, or one inch or more, or two inches or more, water per 24 hours. In some embodiments, the water storage component 10 may have a density of about 40-250 kg/m3 (2.5-15.6 pcf), a thickness of about 5 mm to about 100 mm.
The drainage mat 12 may be substantially similar to the drainage mat 2 described with reference to
In some embodiments, the fleeces 11a and/or 11b and the water storage component 10 can be preassembled by sandwiching the water storage component 10 between layers of one of the fleeces, or between multiple fleeces (e.g., 11a and 11b), prior to placement on the roof. In some embodiments, the water storage component 10 is tightly sandwiched between the two fleeces 11a and 11b, thereby leaving substantially no space between the fleeces and the water storage component 10. In other embodiments, the water storage component 10 is more loosely provided between the fleeces 11a and 11b, or between one of the fleeces 11a and another component of the composite.
The protective fleece(s) 11a and/or 11b can be connected to the water storage component 10. The technology or medium used to connect the protective fleece(s) and water storage component may be, but is not limited to, ultrasonic connections, being loosely laid in pillow form, adhesive, heat bonding, or stitching. Configurations where the water storage component 10 is placed between two layers of fleece or between two fleeces but spacing exists between the water storage component and one or both of the layers or fleeces is also conceived. In some embodiments, ultrasonic connections or stitched side seams may be used to connect any of the components 10, 11a, 11b, 12 with or to each other.
In
In
Sandwiching the water storage component 10 in some fashion between the top 11a and bottom 11b protective fleeces may advantageously allow for the integrity and handling of the mineral roll to be increased. The inclusion of the protective fleeces may particularly aid in handling and integrity when the fleeces and/or water storage component 10, which may be in the form of a mineral wool roll, are wet, as the mineral wool tends to be fragile when wet. Further, the bottom protective fleece 11b may allow for stormwater runoff that is percolated from the mineral wool roll to be slowed. The water storage component 10 may have different water holding qualities from the fleeces 11a and 11b. The water storage component 10 may have more, or less, water retention ability than one or both of the fleeces 11a and 11b.
The composite 50 as described above may be provided in roll or sheet form and installed onto a new or pre-existing roof in rows. The composite, and thus its constituent components, may have a flexibility sufficient to allow for its being provided in roll form. Each row may be sandwiched by a separate set of protective fleeces, or a single set of protective fleeces may sandwich all rows of the water storage component.
In some embodiments, the top fleece 11a may be provided with an extension, for example of 10 mm to 100 mm or more, so as to extend outward from the surface of the water storage component from which it covers. The extension may be along a plane parallel to the surface of the top fleece 11a and may extend beyond the remainder of the components of the composite 50. This extension allows for the top fleece 11a to extend over the abutting portion of an adjacent section of the composites 50 when installed in rows.
In some embodiments, a drainage component in the form of a drainage mat 12 may be placed below the water storage component 10 and/or below the bottom fleece 11b, thereby forming a composite of the protective fleeces 11a and 11b, water storage component 10 and drainage mat 12. The drainage mat 12 may be bonded or adhered to the bottom fleece 11b using heat bonding, or any adhesive process. The drainage mat 12 is provided to allow for runoff of excess stormwater, and may generally aid in water flow. The system generally may allow for a prevention of constant contact of a roof membrane or other urban surface membrane with stored water. The drainage mat 12 may be a three-dimensional, lightweight, and flexible composite material having a drainage core of looped polymeric filaments and optionally bonded to a nonwoven filter fabric.
The water storage component 10, which in some embodiments may be a mineral wool roll, slabs, cubes, or otherwise connected pieces, may, in concert with the protective fleece, retain a predetermined amount of stormwater. In some embodiments, the combination of the mineral wool roll and protective fleece can be designed to retain the first 25 mm or 1 inch of stormwater, or more, so as to comply with requirements of some municipalities.
Referring to
Referring again to FIG. 2A3A in embodiments where the top protective fleece 11a is a filter fabric, the top protective fleece may have the same barrier and filter qualities as the filter fabric 13.
Referring again to
The following examples show some properties of an exemplary, nonlimiting stormwater management apparatus according to the above-described embodiments. Of note, XF 110, XF 154 and XF 108 have been previously described. RM 12/35, GRS MD, GRS 40, PP 100/40 and PP 100/100 are comprised of mineral and/or rockwool rolls or slabs, and XF 301 include a moss-sedum mat configuration.
Regarding Tables 1A and 1B. Table 1 A provides properties of a system using a combination of a top protective fleece of 300 g/m2, a mineral wool roll, a bottom protective fleece of 800 g/m2 and a drainage and filter mat. Table 1B provides properties of a system using a combination of a top protective fleece of 300 g/m2, a mineral wool roll, a bottom protective fleece of 300 g/m2 and a drainage and filter mat.
Table 1A shows a water retention of 26.391/m2. Table 1B shows a water retention of 35.061/m2.
The mineral wool slab 20 may have a density and compressive strength higher as compared to the water storage component as a mineral wool roll 10 discussed above. The mineral wool slab 20 may be provided in slab form and installed onto a new or pre-existing roof in rows. Each row may be sandwiched by a separate set of protective fleeces, or a single set of protective fleeces may sandwich all rows of the mineral wool roll. The mineral wool slab 20 may have different water holding capacities from the fleeces 21a and 21b.
As shown in
Atop the filter fabric 23 and/or top fleece 21a be a ballast layer in the form of permeable or pervious pavers 24. These pavers may be permeable, can be snapped or connected together atop the filter fabric 23 and/or top fleece 21a. The density and strength of the mineral wool slab composite may allow for the pavers to be appropriately supported. During rainfall, the stormwater can go around or through the pavers and be captured in the composite below.
Tables 2A-2C show some properties of a stormwater management apparatus according to the above-described embodiment. Table 2A provides properties of a system using a combination of a top protective fleece of 300 g/m2, a mineral wool slab, a bottom protective fleece of 800 g/m2 and a drainage and filter mat. Table 2B provides properties of a system using a combination of a top protective fleece of 300 g/m2, a mineral wool slab a bottom protective fleece of 300 g/m2 and a drainage and filter mat. Table 2C provides properties of a system using a combination of a top protective fleece of 300 g/m2, a mineral wool slab, a bottom protective fleece of 300 g/m2 and a drainage and filter mat.
Table 2A shows a water retention of 25.391/m2. Table 2B shows a water retention of 38.061/m2. Table 2C shows a water retention of 86.061/m2.
The composite of the protective fleeces 31a and 31b and mineral wool roll 30 allow for a green roof (a roof including the pre-vegetated mat) to achieve a desirable water retention level using growing media at a fraction of the loading required by traditional green roofs.
An optional additional component to the composites described with respect to
Additionally or alternatively, a stormwater management structure may include a reflective top portion so as to reduce solar heat gain and reduce energy use. This reflective top portion may include any of a nonwoven portion, a water permeable coating, a perforated membrane, perforated metal, permeable cement based pavers, aggregate pavers, or loose laid ballast. The coatings or fabrics may be thermochromic to reflect heat or dry out water retention. Under the top portion would be a water retention layer, such as a mineral wool portion similar to portions 10 or 20 described above, and/or a specialty nonwoven or cuspated cup structure. An insulation layer may exist and improve upon the insulation value of the new or existing roof to which this structure is to be included upon. Under the mineral wool portion and/or any insulation layer, a drain (or drain layer) may be included so as to allow excess water to be drained once the water holding capacity has been exceeded. This may be similar to the drain 12 or 22 as described above, or any other serviceable draining device. The water retention layer may be sufficient to allow for evaporation so as to dry out between precipitation events, and nonwovens can be further included so as to further control water runoff.
The composite 50 described herein may also advantageously provide for sound dampening qualities with reference to the structure on which the composite is placed.
Although the preceding description has been described herein with reference to particular means, materials and embodiments, it is not intended to be limited to the particulars disclosed herein; rather, it extends to all functionally equivalent structures, methods and uses, such are within the scope of the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| 62734400 | Sep 2018 | US |
