Abstract:
The system and apparatus according to the invention includes a panel of material which is made up of a body of open cell, reticulated, porous material (e.g., polyurethane foam) surrounded on the sides and bottom by a barrier of waterproof material. A layer of highly reflective, water permeable material is positioned on top of and covers substantially all of the top surface of the body of porous material. A drain can be positioned at the bottom of the panel to provide a slow, gravity feed to release water from the panel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation-in-part application claiming priority to U.S. application Ser. No. 12/845,969, filed Jul. 29, 2010, which is a continuation application of U.S. patent application Ser. No. 11/809,767 filed Jun. 1, 2007, which is a divisional application of U.S. patent application Ser. No. 10/600,625 filed Jun. 20, 2003 (now U.S. Pat. No. 7,407,340), which claims the benefit of prior Provisional Application No. 60/390,097, filed Jun. 20, 2002, all entitled “Modular, Self Contained, Engineered Irrigation Landscape and Flower Bed Panel.” All of these applications and patents are incorporated herein by reference. This application also claims the benefit of U.S. Provisional Application Ser. No. 61/402,581, filed Aug. 31, 2010, which is incorporated by reference herein. 
     
    
     STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention relates to a method and apparatus for a highly reflective cool roof panel installation that reduces the temperature of a roof, thereby reducing the heating ventilation and air conditioning (HVAC) requirements of the structure, and also allows for the capture and retention of storm water which falls on the structure&#39;s roof. The invention also uniquely provides the structure and components to allow for future or immediate planting of plants to provide the additional benefits of a green vegetated roof. 
         [0004]    It is common in modern building and building maintenance operations to attempts to maximize the efficiency of structures (both commercial and residential) through projects that increase the efficiency of the building from an electrical and carbon footprint perspective. It has also been recently recognized that building structures and their water impervious surfaces (roof and parking lots) greatly contribute to non-point source pollution of ground water, tributaries to rivers, rivers, lakes and other bodies of water. 
         [0005]    Modern building standards have been initiated to address these problems in attempts to create more sustainable, “green” buildings. Solutions to the thermal and electrical efficiency of the buildings include various forms of cool roofs that consist of high emissivity, light colored pigments. Typically, methods of accomplishing a cool roof include painting the roof surface with a light colored paint or using a light colored standard roof material such as shingles. The light colored pigment is meant to reduce the absorption of solar energy which in turn reduces the buildup of heat at the roof level. This reduction of heat buildup reduces the HVAC consumption of buildings during the summer months. Other forms of HVAC load reduction include the addition of insulation inside the building at the roof location and the building walls, doors and windows. 
         [0006]    One of the drawbacks of a typical “cool roof” is that in the winter when the ambient temperature is cold and it is required to increase the internal temperature of the structure, the high emissivity, highly reflective surface still reflects and emits the solar energy and heat available instead of capturing it and heating the building roof as is desired in these conditions. Another drawback of high emissivity, cool roofs is that they only provide the one function of cooling the roof in a high temperature situation, providing no other environmentally beneficial function such as collecting or impeding storm water runoff, or improving the thermal and electrical efficiency via an insulative effect. The adding of insulation to the inside or roof of a building does increase the insulation R value of the structure, but, like the cool roof, does nothing to collect or impede storm water runoff. 
         [0007]    With regard to capturing run off from storm water events on structures, state of the art solutions typically include several options: catchment devices, bio-swells, bio-retention plantings and green, vegetated rooftops. Catchment devices range from rain barrels that capture run off from structure roof down spouts to full storm water engineered detention ponds. Rain barrels are the simplest devices that can be located beneath down spouts and collect a typical amount of 55 gallons. While rain barrels provides a cost effective means to catch some storm water runoff with limited capital investment, they only captures a very small percentage of the rainfall that falls on a rooftop. In between rain barrels and engineered detention ponds are cisterns and buried cisterns, which allow capture of larger amounts of storm water but cost significantly more and require extensive excavation, disturbance of the structure site and installation efforts and labor. Finally, the most expensive, intrusive and labor intensive storm water capture solution is the installation of engineered storm water detention pond to capture storm water runoff. While when complete these engineered detention ponds can capture storm water, they typically significantly reduce the usable real estate surrounding the structure, and greatly raise the land development cost per square foot. Also, the options of detention ponds are typically not available for existing structure sites where the structure and hardscapes have been completed. These prior systems, although expensive and flawed, still are used because one of the largest contributors to non-point source pollution of urban areas has been determined to be run off from rooftops and parking lots. 
         [0008]    Also leading to the requirements for these prior art systems is that the storm water control systems in cities under the roads and pavement infrastructure have typically been in existence for many years or decades and were not designed and cannot handle and absorb all of the storm water runoff from the roofs and hardscapes that now exist and drain into these storm water systems. As one can imagine, it is not cost effective or practical to go back to these systems and enlarge them to accept this additional storm water flow. Another downside and serious consequence of these limited storm water systems is that when the storm water overwhelms the system, raw untreated sewage and waste water can be discharged into bodies of water that people have contact with, creating an unsafe health situation. The existing storm water systems built in previous decades simply cannot deal with the additional storm water runoff created by the additional impervious rooftops and landscaping (parking lots, sidewalks, etc.) that have replaced natural water absorbing green ways and undeveloped land. 
         [0009]    Another approach to capturing this storm water off of rooftops has been green, vegetated rooftops. Growing plants on rooftops is common in the more temperate climates of Europe but it is much more difficult in the hotter climate of the United States of America. The requirement for lightweight soil that is drained has limited the plant palate for vegetated rooftops. The soil has to be lightweight to be supported on a roof and it has to be drained in order to allow oxygen to the roots of the growing plants, as plants need oxygen as much as water. These current requirements greatly limit the amount of storm water that can be captured from a green roof. 
         [0010]    All in all, no one prior art system has been developed which can provide a cost effective cool roof system that provides: a high additional insulation factor, an immediate capacity to fully capture the storm water runoff from a roof generated by a rainfall event, the infrastructure to be planted in the future as a green roof if so desired to capture additional environmental benefits. 
       SUMMARY OF THE INVENTION 
       [0011]    It is therefore a general objective of the current invention to overcome the above-described limitations of existing state of the art cool roof systems and storm water event collection systems and to provide an integrated, cost effective means to accomplish an integrated cool roof and storm water collection system which simultaneously provides the installed infrastructure for a fully functioning green roof. 
         [0012]    In order to accomplish the objectives of the current invention, the system and apparatus according to the invention includes a panel of material which is made up of a body of open cell, reticulated, porous material (e.g., polyurethane foam) surrounded on the sides and bottom by a barrier of waterproof material. A layer of highly reflective, water permeable material is positioned on top of and covers substantially all of the top surface of the body of porous material. A drain can be positioned at the bottom of the panel to provide a slow, gravity feed to release water from the panel. 
         [0013]    The waterproof barrier can be a polyethylene plastic liner, spray-on waterproofing material or any other suitable moister barrier on the bottom and sides of the body. In the preferred embodiment, as described hereinbelow, the barrier can be of polyolefin material molded to the shape of a water tight tray and can have a range of thickness from a film of a few thousandths of an inch to a thickness of many tenths of inches. The shell can also be formed with raised nodules which allow for air flow and drainage between the raised bottom surface of the thermoformed polyolefin shell and upper roof surface that the panels are located on. 
         [0014]    The open cell, reticulated, porous material can be polyurethane foam, bonded crumb rubber with a polyurethane binder or any material with the properties and ability to hold a significant volume of water per volume of material while maintaining air trapped within the material in a non-drained state. 
         [0015]    The layer of highly reflective material positioned on the top surface of the panel is intended to reflect a significant portion of the solar energy directed at the rooftop surface. At the same time, the water permeability of this material allows rainwater falling upon the panel to pass through and absorb into the panel material. This layer of material can be a light colored or white fabric such as spunbound polypropylene or cotton. This layer of material could also be a thin layer of paint sprayed or coated on the top surface of the body of porous material. It is also anticipated that, in one embodiment, the body of porous material itself could be light colored or white or otherwise have a high reflectivity value. 
         [0016]    It can be advantageous to vary the emissivity of the layer of reflective material with the application. For example, in cooler climates where, during the winter months, it is desirable to maintain heat within the building structure, the layer of material can have a low emissivity value in order to retain a greater portion of the absorbed heat in the panel. On the other hand, in hotter climates it may be desirable to have a layer of material with a high emissivity which emits the heat absorbed into the panel. 
         [0017]    The drain positioned at the bottom of the panel can be associated with a drain line so that water released from the panel through the drain travels through the drain line to a secondary location and a valve can be associated with the drain and drain line to prevent or vary the rate of flow of water from the panel. 
         [0018]    A fluid emission device can be attached on a side, top or bottom location of the panel and is associated with the panel so it can emit water into the panel at a desired rate. Connection lines or tubing can be used to connect the fluid emission device to a pressurized fluid source which can be used to provide water or other fluid to the panel. 
         [0019]    In one embodiment of the present invention, a plurality of panels can be assembled into a system of panels for cooling a roof and having water retention and draining capabilities. First, a plurality of panels as described can be installed on a rooftop or elevated surface by placing the panels on the surface and then securing the adjacent panels to each other with the use of connection sleeves, clips, plastic ties, interlocking latches or other methods of attachment. 
         [0020]    The attached panels, which can form a grouping of panels, can then be attached to the building structures through various attachment systems, one example being a steel cable which can be attached to the side of the building or parapet and then positioned across the tops of the panel(s) to secure the panels to the roof surface and prevent any potential wind uplift or removal. 
         [0021]    The panel&#39;s fluid emission devices can be attached to a pressurized water source line to provide water to the panels if live plants are inserted into the panels. The panel&#39;s drains and drain lines can be connected to a non-pressurized, gravity feed water collection system to slowly allow the collected storm water to be drained off in a controlled manner. The collection system can be a water collection tube or tubes associated with a flow control valve which directs storm water away from the panels. 
         [0022]    The panel(s) can also be planted with live plants by creating openings in the layer of reflective material and the top surface of the body of porous material and inserting the roots of the plant into the openings. 
         [0023]    The roof cooling panel system of the present invention is accomplished by installing the panels and securing them to a roof or elevated structure. Once secured, the panels act on several levels to enhance the thermal/electrical performance and the storm water capture and retention ability of the structure. First, the panels enhance the thermal efficiency of the structure by providing a solar energy reflecting surface. The highly reflective layer of material on top of the panels reflects the solar energy and can emit absorbed heat reducing the to temperature of the panel and correspondingly the temperature of the roof surface. A reduction in the roof surface temperature corresponds to a reduction of heat buildup in the top of the structure and a reduction in the HVAC requirements of the building. 
         [0024]    In addition to the heat reduction, the panels can also act to provide thermal insulation as the open cell, reticulated material has an increased R value over standard roofing materials and provides thermal resistance. In experimentation, the open cell foam material has been able to demonstrate a 300 degree differential across a three inch thick sample. The material&#39;s ability to restrict heat transfer acts as a traditional insulative material placed directly on top of the roof which further enhances the thermal envelope of the structure in addition to low emissivity and solar reflection. This second thermal efficiency is beneficial because just adding a conventional state of the art high emissivity cool roof provides enhancement in high solar, warm conditions but is not effective in cold, winter climates where it is beneficial to absorb the solar energy to provide warmth to the buildings. The secondary thermal effect will help retain heat from within the structure. 
         [0025]    The panels can also have the effect of capturing significant amounts of storm water that falls on the structure&#39;s roof and the composition panels. Tests have shown that when the open cell polyurethane foam material is contained in a substantially waterproof shell it will retain approximately two and one half inches of rainwater in a three inch thick section of the material. This capture rate indicates that the material can stop significant amounts of storm water from running off of the tops of roofs where the panels are installed. The panels become a form of a distributed capture system on the rooftop. 
         [0026]    The panel also has other advantages. The captured water is all contained within the reticulated, open cell porous material with no continuous surface water where mosquitos or other pests can breed and become a hazard. Also, while a large roof structure with the panel system can retain and hold thousands of gallons of storm water, the potential for a drowning hazard, as can be found in cisterns, tanks and open storm water detention ponds, is eliminated. The open cell, reticulated material also acts to provide an initial filtration of the storm water so as to make it acceptable for irrigation usage or other non-potable usages such as toilet flushing in the structure. Once the storm water is captured in the panels, it can be slowly released through the drain and associated drain lines that are plumbed to a gravity feed line and can be bled out into an alternate storage location or into the storm water drainage system at a much slower rate than the instantaneous storm discharge rate, reducing the pressure on the existing storm sewer system. The water stored in the panels can also be removed by living plants which can be planted in the panels and which will transpire the water into the atmosphere. 
         [0027]    The ability of a “cool roof” to subsequently install plants in the panels and capture the additional benefits of being a green roof is completely unique to the present invention. This ability allows for the structure to gain the significant advantages of the panels as described above and at the same time be “pre-wired” for a green roof installation as funds and capital expenditure money become available later in the life of the structure. The installation of the plants for the green roof are done very simply by creating an opening in the layer of reflective material on top of the panel and in the open cell polyurethane foam beneath, then inserting the living plant of choice. The roots will then grow into the open cell reticulated, porous material where it will have access to retained water and trapped air within the material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]      FIG. 1  is a top elevation of a panel of the preferred embodiment of the present invention. 
           [0029]      FIG. 2  is a side section elevation of the preferred embodiment of the present invention through Section Line  2 - 2  of  FIG. 1 . 
           [0030]      FIG. 3  is a top elevation drawing depicting a cool roof panel system installed on a rooftop of a building. 
           [0031]      FIG. 4  is a side sectional elevation of the preferred embodiment through Section Line  4 - 4  of  FIG. 3  depicting two side by side panels of the preferred embodiment of the present invention. 
           [0032]      FIG. 5  is a side elevation depicting an alternative embodiment of the present invention depicting plants or vegetation planted in the panel for a green roof application. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    The present invention provides a cool roof panel system for increasing the reflectivity and rainwater capture and retention ability of rooftops and simultaneously increasing the rooftop&#39;s R value and thermo insulation.  FIG. 1  is a top elevation of the preferred embodiment of a single panel  20  on a surface  22 , such as a rooftop.  FIG. 2  is a sectional view of the preferred embodiment through Section Line  2 - 2  of  FIG. 1 . The panel  20  is comprised of a body or layer of open cell reticulated, porous material  24 . A water impermeable barrier  32  is positioned adjacent the side and bottom surfaces of the body  24 . The top surface  27  of the panel  20  is substantially covered with a layer of water permeable material  31  having high reflectivity and high emissivity. A fluid emission device  34  can be positioned to emit water into the body  24  and can be connected to an external pressurized water source  17 . A drain  18  is positioned at the bottom of the panel  20  and is connected to a drain line  19 . The entire panel  20  can be placed on a rooftop  22  or other desired surfaces. 
         [0034]    In the preferred embodiment, the body of open cell reticulated, porous material  24  is an open cell polyether polyurethane foam. The thickness of the body of porous material  24  is, preferably, three inches. It is also preferred that the three inch body of porous material  24  will capture and retain the equivalent of two and one-half inches of rainwater hitting the surface of the body of porous material. However, the amount of captured rainwater could vary with the pore size of the material  24 . It is also anticipated that the thickness could vary depending on the water capture and retention requirements and the structural capabilities of the building. When filled with rainwater, the body of porous material  24  and the barrier  32  together typically weigh less than fifteen pounds per square foot, which allows the panel  20  to be installed on existing and new building rooftops, vertical walls, fencing, lattice or other structures with no additional structural support systems required. 
         [0035]    Although preferably a single piece of porous material, the body of porous material  24  may be multiple pieces of porous material placed adjacent to one another. For example, the body of porous material  24  may include multiple lateral adjacent pieces of porous material. Similarly, the body of porous material  24  may be multiple vertically adjacent pieces of porous material, such that a first layer is placed atop a second layer. 
         [0036]    In the preferred embodiment, the water impermeable barrier  32  is a thermo formed polyolefin hardened shell having a thickness between one and two millimeters formed into a tray with sidewalls  36  and a bottom  38 . However, it is anticipated that this barrier could be a thin, flexible film or a hardened shell with greater thickness. The height of the sidewalls is sufficient to contain the body of porous material  24 . The bottom  38  of the barrier  32  has an interior surface on which the body of porous material  24  rests and an exterior surface  40  which rests on the rooftop surface  22  or other desired surface. In the preferred embodiment, raised nodules  42  extend from the exterior surface  40  of the bottom  38  of the barrier  32 . The nodules  42  have a height of three-eighths of an inch to one inch providing space  44  between the bottom  38  of the barrier  32 , and the rooftop surface  22 . This space  44  provides for air flow and room for the drain line  19 . 
         [0037]    In the preferred embodiment, the layer of water permeable material  31  covering the top surface  27  of the body of porous material  24  is preferably a white permeable fabric. In one embodiment, the layer of material  31  is a white, spunbound polypropylene. The white color of the fabric allows it to reflect a high percentage of solar energy and the permeability allows rainwater to pass through the layer of material  31  into the body of porous material  24 . However, it is anticipated that a range of light colored fabrics of other materials can serve to provide acceptable reflectivity. For example, the layer of material  31  could be a permeable fabric or a rolled on or sprayed on permeable paint. In one embodiment, the body of porous material  24  itself could provide acceptable reflectivity and thereby eliminate the need for a layer of reflective material. 
         [0038]    The reflectivity of a material is typically given as a percentage of the light incident on the material which is reflected by the material. The remaining amount of light is absorbed or passes through the material. It is preferred that the layer of reflective material in the present invention have a reflectivity value of 50% or greater. 
         [0039]    In general, emissivity refers to the ability of a surface to emit heat by radiation. A value for emissivity is typically given in terms of the ratio of thermal energy emitted from the surface of a material to the thermal energy emittance of a hypothetically-perfect emitter which is given a value of 1 (a perfect emitter is called a black body whose emitted energy would follow a Planck distribution). Thus, the emissivity value of a material will be less than 1 and is typically given as a decimal number (e.g., 0.80) or as a percentage. Most roofing materials have an emissivity value of 0.085 or higher. 
         [0040]    In the preferred embodiment of the present invention, the layer of material positioned on the top surface  27  of the body of porous material  24  will have an emissivity value of 0.50 or higher. However, it is anticipated that materials with lower emissivity values can be used, especially when the material has a high reflectivity value or where the panels are used in cooler climates where during cold months of the year it is desirable to retain a higher percentage of the absorbed heat. 
         [0041]    As shown in  FIG. 2 , a drain  18  is positioned at the bottom of the panel  20  and allows collected rainwater to drain through the barrier  32 . A drain line  19  associated with the drain  18  carries the released water to a secondary location. In the preferred embodiment, this drain  18  or drain line  19  is associated with a one way drain valve  21  which allows the control of the flow of collected water into the drain line  19  to a secondary location. 
         [0042]    As shown in  FIGS. 1 and 2 , the preferred embodiment of the present invention also has a fluid emission device  34  associated with a fluid inlet for the panel  20 . In this embodiment, the fluid inlet is an opening  46  through a sidewall  36  of the barrier  32  and the fluid emission device  34  is disposed through the sidewall at that opening  46 . As shown in  FIG. 2 , the fluid emission device  34  can be connected to a pressurized water source  17 . In the preferred embodiment, the fluid emission device  34  is a drip emitter. However, the fluid emission device  34  may be any apparatus sufficient to emit water into the body of porous material  24 , such as a flow control disk or even a simple garden hose. It is also anticipated that there may be no fluid emission device  34  and the fluid inlet  46  may simply be the top surface  27  of the body of porous material  24 . 
         [0043]      FIG. 3  depicts the cool roof panel system  60  of the preferred embodiment of the present invention. In this system, a plurality of panels  20  are positioned on a rooftop  22 . Preferably, each of the panels  20  are placed adjacent to other panels  20 . A series of cables  62  are secured at each end to the rooftop  22  or other building structure. The cables  62  are strung across the top of the panel system  60  to prevent movement or lifting of the panels  20  or panel system  60  due to wind. The cables are threaded through eye bolts  63  fastened to the rooftop  22 , with the ends of each cable clamped to the body of the cable  62 . 
         [0044]      FIG. 4  shows a cross section of two adjacent panels  20  at Line  4 - 4  of  FIG. 3 . Each of the adjacent panels are as described above with regard to a single panel  20 . The adjacent panels  20  are connected with a connection sleeve  64 . In the preferred embodiment, the connection sleeve  64  has a generally blocked u-shape cross section with two leg members  66  and a base member  68 . The connection sleeve  64  is positioned over the adjacent sidewalls  36  of the two adjacent panels  20  such that the adjacent sidewalls  36  are positioned between the leg members  66  of the connection sleeve  64  and the base member  68  is positioned adjacent the top edges of the sidewalls  36 . Each leg member  66  of the connection sleeve  64  is positioned between the body of porous material  24  and the sidewall  36  of each adjacent panel  20 . The lengths of the connection sleeve  64  can vary. For example, it can be equal to the length of the sidewalls  36  or some fraction of that length. 
         [0045]    It is also anticipated that other methods of attachment of two adjacent panels  20  may be used. For example, adhesives, interconnecting latches, hook-and-loop straps or patches, plastic ties or other methods known in the art could be used. A cable  62  extends over the patent  20  to prevent movement or lifting of the panels  20  or panel system  60  due to wind. The cable  62  are threaded through an eye bolt  23  fastened to the rooftop  22 , with the ends of each cable clamped to the body of the cable  62  with a clamp  65 . 
         [0046]    Still referring to  FIG. 4 , each of the panels  20  has a drain  18  connected to a drain line  19  as described above. The drain lines  19  feed into a collection tube  70  which drains the collected rainwater from the panels  20  (and, more generally, from the panel system  60  shown in  FIG. 3 ) to a secondary location. A flow control valve  72  can be positioned in or proximal to the collection tube  70  to control the rate of flow of the water from the panel system  60 . 
         [0047]    In one embodiment of the present invention, the collection tube  70  can direct rainwater to a storm water sewer (not shown) system. In other embodiments of the present invention, the collection tube  70  can direct the water to rainwater storage units (not shown) for reuse such as irrigation or other non-potable uses. 
         [0048]      FIG. 5  shows an alternative embodiment of the present invention. In this embodiment, a plurality of first openings  74  are formed through the layer of material  31  positioned on the top surface  27  of the body of porous material  24 . Corresponding plant second openings  76  are also formed in the body of porous material  24  subjacent the first openings  74 . In the preferred embodiment, the first openings  74  and second openings  76 , are slits through the top layer of material  31  and the top surface  27  of the body of porous material  24 , respectively. The roots  78  of selected plants  80  can grow within the body of porous material  24  with the stems  82  of the selected plants  80  extending up from and through the first openings  74  and second openings  76 . When inserted into the second openings  76  in the body of porous material  24 , the roots  78  may be bare or accompanied with soil in the form of a root ball. Air and water captured within the body of porous material is made available to the roots  78  of the selected plants  80 . The roots  78  can easily grow through the pores of the body of porous material  24 . 
         [0049]    Water can be provided to the roots of the plants  80  through the fluid emission device  34 . In this embodiment, it may be unnecessary to drain captured rainwater from the panel  20 . Instead, the rainwater can be removed by the plants  80  growing within the body of porous material  24  and/or evaporate from the panel  20 . 
         [0050]    The present invention is described in terms of preferred embodiments in which a specific system and method are described. Those skilled in the art will recognize that alternative embodiments of such system, and alternative applications of the method, can be used in carrying out the present invention. Other aspects and advantages of the present invention may be obtained from a study of this disclosure and the drawings, along with the appended claims. Moreover, the recited order of the steps of the method described herein is not meant to limit the order in which those steps may be performed.