Abstract:
A heating system for use with roofing shingles, the heating system including a flexible grounding layer having a transverse dimension that is no greater than substantially equal to a transverse dimension of the roofing shingles, a flexible heater laminated to the flexible grounding layer, wherein the flexible heater includes a substrate, a conductive resistive ink pattern disposed on the substrate, wherein the ink pattern generates heat when electricity passes through the ink pattern, wherein the heating system includes a nailing portion that extends longitudinally along one side of the heating system, the nailing portion of the heating system having a transverse dimension that is at least substantially equal to a transverse dimension of a nailing portion of the roofing shingles, wherein the flexible heater is disposed on the flexible grounding layer such that the ink pattern is disposed outside of the nailing portion of the heating system.

Description:
CROSS-REFERENCE TO RELATED ACTIONS 
       [0001]    This application claims the benefit of, prior U.S. Provisional Application No. 61/473,472 filed Apr. 8, 2011, which is incorporated by reference herein in its entirety. 
     
    
     BACKGROUND 
       [0002]    Typically, in the construction of homes it is important to protect roofs from leaks due to ice and rain. Traditionally, felt paper was secured to wooden roofs underneath shingles. The felt paper would absorb ice or water that penetrated the shingles, preventing it from reaching the underlying wood. Nailing the felt paper to the roof, however, caused spaces around the nail through which water could seep. The water could follow the nail into the wood, causing leaks in the home. To solve this problem, water shields began to include an adhesive backing to fasten the shield to the wood, instead of using nails. The adhesive backing includes a peel-able strip which, when removed, exposes the adhesive layer for affixing the water shield to the unprotected wooden roof. The top of these water shields were made of a rubberized asphalt material, which created a gasket effect on the shaft of the nail driven through it. These water shields were successful in preventing many types of leaks. 
         [0003]    In colder climates, however, ice dams can form and allow water to penetrate or flow under the water shield. For example, an ice dam can prevent melt-water from flowing downward off the roof, which can result in the water seeping into the house above the ice and water shield coverage area. Ice dams occur when snow accumulates on the roof of a house with inadequate insulation. Heat conducted through the insufficiently insulated roof, and warm air from the space below, warms the roof and melts the snow on areas of the roof that are above living spaces. It does not, however, melt the snow over cold areas, such as roof overhangs. In these situations, melt-water from the heated areas of the roof flows down the roof, under the blanket of snow, onto the overhang and into the gutter, where colder conditions permit it to freeze. Eventually, ice accumulates along the overhang and in the gutter. Snow that melts later cannot drain properly, backs up on the roof and can result in damaged ceilings, walls, roof structure, and insulation. To avoid this many building codes require a water shield covering the roof two feet into the living space. 
       SUMMARY 
       [0004]    A heating system for use with roofing shingles, the heating system including a flexible grounding layer having a transverse dimension that is no greater than substantially equal to a transverse dimension of the roofing shingles, a flexible heater laminated to the flexible grounding layer, wherein the flexible heater includes a substrate, a conductive resistive ink pattern disposed on the substrate, wherein the ink pattern generates heat when electricity passes through the ink pattern, wherein the heating system includes a nailing portion that extends longitudinally along one side of the heating system, the nailing portion of the heating system having a transverse dimension that is at least substantially equal to a transverse dimension of a nailing portion of the roofing shingles, wherein the flexible heater is disposed on the flexible grounding layer such that the ink pattern is disposed outside of the nailing portion of the heating system. 
         [0005]    Various aspects of the invention may provide one or more of the following capabilities. A radiant heat deicer can be provided. Radiant heat can be provided when desired to melt ice dams and/or snow. The amount of ice dam damage caused on a roof can be reduced. Icicles hanging from a roof can be reduced. Roofs can be protected from water and ice damage using radiant heat. Radiant heating can be installed along with shingles on a roof. The power consumed by a heating system can be reduced. Installation time of the heating system can be reduced. These and other capabilities of the invention, along with the invention itself, will be more fully understood after a review of the following figures, detailed description, and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0006]      FIG. 1  shows a wooden roof without an ice and water shield or shingles. 
           [0007]      FIG. 2  shows a standard 3-tab shingle. 
           [0008]      FIG. 3  shows a wooden roof with several courses of shingles attached. 
           [0009]      FIG. 4  is an exploded cross-sectional view of the heating system shown in  FIG. 5 , taken along line I-I in  FIG. 5 . 
           [0010]      FIG. 5  is an exemplary heating system. 
           [0011]      FIG. 6  is an example of part of the heating system shown in  FIG. 5 . 
           [0012]      FIG. 7  is an exemplary exploded cross-sectional view of a heating system 
           [0013]      FIG. 8  is an exemplary technique of installing courses of shingles and heating systems. 
           [0014]      FIG. 9  shows a wooden roof with snow on top. 
           [0015]      FIG. 10  shows heat radiating through the snow on the wooden roof shown in  FIG. 9 . 
           [0016]      FIG. 11  is an exemplary control unit. 
           [0017]      FIG. 12  is an exemplary process of controlling a heating system. 
           [0018]      FIG. 13  shows an exemplary installation of a heating system on a roof. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Embodiments of the invention can provide techniques for preventing and eliminating ice dams and snow buildup on roofs. A flexible layered heating system includes a grounding layer and a heating layer. The heating system can be sized such that its height is approximately the same as a standard shingle. In this configuration, the heating layer is only located in a bottom portion of the heating system so that when the heating system is installed under a layer of shingles, that the shingles can be nailed to the roof using common construction techniques without damaging the heating layer. The heating system can be rolled out onto a roof before a subsequent course of shingles is nailed to the roof. A heating system can be installed under one or more courses of shingles on a roof, as desired to melt snow and ice. The heating system can also be controlled by an automated controller that senses temperature, moisture, and/or precipitation. Other embodiments are within the scope of the invention. 
         [0020]    Referring to  FIG. 1 , a house  100  is shown with an unprotected wooden roof  110 . The wooden roof  110  includes an overhang  120  that extends beyond a heated living area of the house  100 . Overhang  120  is typically an area where ice dams can form. Typically, the roof  110  is covered with shingles, such as standard asphalt shingles, although other types of shingles can be used (e.g., wood, clay, etc.). 
         [0021]    Referring to  FIGS. 2-3 , a standard 3-tab shingle  200  is shown. The shingle  200  includes a nailing portion  205 , and three tabs  210 . In a typical installation, shingles  200  are applied to the roof  110  in a series of rows called courses (e.g.,  305  in  FIG. 3 ). Typically, a starter course of shingles is nailed to the roof  110  in such a manner that a top  215  of the shingle is even with the bottom of the roof  110  (e.g., the first starter course of shingles is installed upside down). In some embodiments, the tabs  210  may be cut off the starter course. A first course is then applied on top of the starter course such that a bottom  220  of the shingle is even with the bottom of the roof  110  (e.g., the first course can be applied directly on top of the starter course). In order to cover the rest of the roof  110 , subsequent courses of the singles  200  are applied in a partially-overlapping manner such that the tabs  210  of one course of shingles are placed over the nailing portion  205  of the course below it. 
         [0022]    Referring to  FIGS. 4-5 , an embodiment of a heater system that can be used to prevent ice dams is shown. Heating system  405  can be a flexible laminated continuous sheet heater that includes a ground shield  415 , an adhesive layer  420 , and a heater  425 . The ground shield  415  can be aluminum (e.g., aluminum foil), although other grounding materials can be used. Preferably, the ground shield is configured such that a nail can be hammered through it. The adhesive layer  420  is preferably construction grade adhesive that can bond to underlayments such as plywood, ice dam barrier, and asphalt shingles and can permanently bond the heater  425  to the ground shield  415 . In embodiments where the heater  425  is smaller than the ground shield  415  leaving exposed adhesive  420  (e.g., as shown in  FIG. 4 ), the exposed adhesive can be covered by a release liner (e.g., poly or kraft paper  410 ) that can be removed before installation. The adhesive can be used to adhere the heating system  405  to the shingles and/or plywood roof. In one embodiment, the ground shield  415  is 0.003 to 0.005 inches thick, the adhesive layer  420  is 0.04 to 0.08 inches thick, and the heater  425  is 0.014 inches thick. Preferably the heater  425  is configured to operate at 6-14 watts per linear foot. Other thicknesses and wattages are possible. 
         [0023]    The heater  425  can be a plastic substrate on which is printed heating element  430 , although other substrates are possible (e.g., rubber, metal). For example, the heater  425  can be a pattern of conductive resistive ink that generates heat as electricity passes through it (e.g., via Joule heating). The heater  425  can include i) a pair of longitudinal stripes  435  extending parallel to and spaced apart from each other and ii) a plurality of bars  440  spaced apart from each other and extending between and electrically connected to the stripes  435 . In this configuration, one of the longitudinal stripes  435  can act as a positive bus, and the other longitudinal stripe  435  can act as an negative bus, thus causing a flow of electricity through the bars  440 . An embodiment of the heater  425  is described more fully in each of the following U.S. Pat. Nos. 4,485,297, and 4,733,059 each of which are incorporated by reference herein. Other configurations of the heater  425  are possible. A photograph of one embodiment of the heater  425  is shown in  FIG. 6 . 
         [0024]    The spacing of the bars  440  can be configured to cause substantially uniform heating. For example, the width of each bar  440  can be greater than the space between adjacent bars, and the space between bars  440  can be less than an inch, preferably in the range of about ⅛″ to 1″. The widths of the heating bars is typically in the range of about ⅛″ to about 2″, preferably about ¼″ to ½″, although other widths are possible. Other pattern designs for the arrangement of the heater  425  are possible, such as those disclosed in U.S. Pat. No. 4,485,297, which is incorporated by reference herein in its entirety. 
         [0025]    The heater  425  can also contains electrodes connected to copper strips extending from an end of the longitudinal stripes  435 . Generally, as described in U.S. Pat. No. 4,485,297, the electrodes can provide an electrical connection between the heater  425  and a control unit, which can be, in turn, connected to a power source. 
         [0026]    The heating system  405  can be approximately the same height as a standard asphalt shingle (e.g., 13¼ inches), although other sizes are possible. The heating system  425  can be divided into two portions: a heater portion  445  and a nailing portion  450 . The heating system  405  can be configured such that the nailing portion  450  is the top half of the heating system  405 , and the heater portion  445  is the bottom half of the heating system  405  (e.g., above and below line  455 ). The heating system  405  can be configured such that the heater portion  445  is approximately the same size as the tabs  210  of the shingle  215 , and the nailing portion  450  is approximately the same size as the nailing portion  205  of the shingle  215 . 
         [0027]    The heater  425  of the heating system  405  can be configured in various manners. For example, the plastic substrate of the heater  425  can be approximately the same size as the conductive pattern printed thereupon (e.g., as shown in  FIG. 4 ), or the plastic substrate can be much larger providing additional surface area to install the heating system  405 . To the extent that the plastic substrate is sized such that it extends into the nailing portion  450  (e.g., as shown in  FIG. 7 ), preferably the conductive pattern printed thereupon does not extend into the nailing portion  450 . 
         [0028]    The heating system  405  can be installed on a roof such that it melts snow and ice that accumulates on the roof. Referring to  FIG. 8 , preferably one of the heating system  405  is installed for each course of shingles  215  that is installed on the roof. The heating system  405  is preferably installed under each corresponding course of shingle. The heating system  405  can be installed on only the first few courses (e.g., where ice dams a likely to form), or can be applied on the entire roof. The heating system  405  can also be sized such that it can be placed in each course of the peaks and valleys that are found in complicated roof designs. In another embodiment, the heating system  405  can be large enough to cover multiple courses (e.g., with alternating heating and nailing portions). In this embodiment, the heating system  405  can be placed directly on the roof, rather than under each course of shingles. In another embodiment, the heating system  405  can also be placed in other locations such as the point above an exterior and/or interior wall. 
         [0029]    Referring to  FIG. 9 , snow  900  covers the roof of house  100 . Directly beneath the snow  900  is weather resistance protective covering, such the shingles  200 . As discussed above, below each course of shingles is the heating system  405 . It is worth noting that snow  900  covers both overhang  120 , as well as areas of the roof extending inwardly from the overhang to above the heated living areas of house  100 . 
         [0030]    Referring to  FIG. 10 , radiant heat  1005  provided by heating system  405  can be seen radiating upwards up through snow  900 . Radiant heat  1005  heats the area above the heating system  405 , which includes the area above overhang  120 . Preferably, the heating system  405  (made up of multiple courses, if desired) extends from the edge of overhang  120  up the pitch of the roof to a portion above the heated living areas of home  100  (typically 2′ into the heated living space). Radiant heat  1005  therefore melts snow  900 , while also preventing melt-water from the top of the roof from re-freezing on or near overhang  120 . 
         [0031]    Referring to  FIG. 11 , the heating system  405  can be controlled by control unit  1100 . The control unit  1100  is preferably installed in an area of house  100  not exposed to the elements, and is electrically connected to the heating system  405 . The control unit  1100  can be connected to the heating system  405 , a thermostat/sensor  1110 , a moisture/precipitation sensor  1115 , and a power source  1120 . The thermostat/sensor  1110  can be part of the control unit  1100 , or can be a separate unit that connects to the control unit  1100 . In addition, while shown separately, the thermostat/sensor  1110  and moisture/precipitation sensor  1115  can be combined in a single sensor unit. Preferably, the thermostat/sensor  1110  and moisture/precipitation sensor  1115  are installed at the coldest area around the gutter of the house, in a place that is not subject to direct sunlight to ensure that when the moisture/precipitation sensor  1115  is dry, the entire gutter area is dry. In this position, thermostat/sensor  1110  can also determine the ambient air temperature. Control unit  1100  can use information from thermostat/sensor  1110  and moisture/precipitation sensor  1115  to make a determination as to whether power should be supplied to the heating system  405 . While the moisture/precipitation sensor  1115  is described as being a combined sensor, another configuration is a sensor that only detects moisture or only detects precipitation. 
         [0032]    In operation, referring to  FIG. 12 , with further reference to  FIGS. 1-11 , a process  1200  for controlling the heating system  405  using the control unit  1100  includes the stages shown. The process  1200 , however, is exemplary only and not limiting. The process  1200  may be altered, e.g., by having stages added, changed, removed, or rearranged. The process  1200  can be i) continuously run so that the heating system  405  is always ready, ii) run at specified intervals (e.g., every 20 minutes), and iii) at the direction of an operator. 
         [0033]    At stage  1205 , the control unit  1100  measures outside air temperature. This can be done by measuring the ambient temperature with thermostat/sensor  1110 . 
         [0034]    At stage  1210 , the control unit  1100  then determines whether the ambient temperature is at or below a predetermined threshold. For example, the control unit can determine if the temperature is at or below 32 degrees Fahrenheit. In other embodiments, the temperature can be set a few degrees higher than freezing, such as 35 degrees Fahrenheit. If the temperature is at or below the predetermined threshold, the process  1200  continues to stage  1215 , otherwise the process  1200  continues to stage  1205 . 
         [0035]    At stage  1215 / 1220 , the control unit  1100  uses moisture/precipitation sensor  1115  to determine if the sensed moisture and/or precipitation level is at or above a predetermined threshold. If the moisture and/or precipitation level is above the threshold, the process  1200  continues to stage  1225 , otherwise the process continues to stage  1205   
         [0036]    At stage  1225 , the control unit  1200  activates the heating system  405  by supplying power from power source  1120 . The control unit  1200  preferably keeps the heating system  405  activated until the precipitation and/or moisture level falls below the predetermined threshold, and/or the temperature exceeds the predetermined threshold. The control unit  1200  can also be configured to activate the heating system  405  for a predetermined time period (e.g., 2 hours) after the temperature and moisture/precipitation thresholds are triggered. 
         [0037]    The process  1200 , vis-à-vis the two-step determination of temperature and moisture/precipitation, can reduce the amount of power consumed by the heating system  405  to prevent the formation of ice dams. If the temperature is above the freezing point in step  1210 , e.g., 50 degrees Fahrenheit, then there is little concern that snow or melt-water will freeze at overhang  120 , forming an ice dam. Therefore, the continuous sheet heater does not need to be operated. Turning the sheet heater on or off can be accomplished by simply providing power to the heating system  405  or preventing power from being supplied to the heating system  405 , in accordance with the sensed conditions as described above. Further, if the temperature is determined to be at or below 35° F. in step  1210 , no ice or water will freeze to form an ice dam, if no precipitation and/or moisture is detected in step  1220 . Accordingly, heating system  405  should not be active. In the event that the temperature is at or below the freezing point and moisture is detected, than the formation of an ice dam is possible. To prevent the formation of the ice dam, the heating system  405  can be activated by control unit  1100 . 
         [0038]    The process  1200  and the controller  1100  are preferably configured to operate without any intervention by a user. For example, a homeowner can configure the controller  1100  once, and can the controller  1100  can preferably function without any further input by the homeowner. 
         [0039]    Referring to  FIG. 13 , an exemplary installation of the heating system  405  is shown. For example, the heating system  405  can be installed on top of standard ice and water shield using adhesive and/or nails before the starter course of shingles is applied. Subsequent courses of the heating system can then be installed as desired. 
         [0040]    Other embodiments are within the scope and spirit of the invention. For example, while the foregoing description has focused on the heating system  405  being used to prevent/remove ice dams, the heating system  405  can also be configured to melt snow off of an entire roof (e.g., when snow weight is a concern). In addition, instead of using the process  1200 , the heating system  405  can be controlled manually. 
         [0041]    The subject matter described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. The subject matter described herein can be implemented as one or more computer program products, such as one or more computer programs tangibly embodied in an information carrier (e.g., in a machine-readable storage device), or embodied in a propagated signal, for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers). A computer program (also known as a program, software, software application, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file. A program can be stored in a portion of a file that holds other programs or data, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub-programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network. 
         [0042]    The processes and logic flows described in this specification, including the method steps of the subject matter described herein, can be performed by one or more programmable processors executing one or more computer programs to perform functions of the subject matter described herein by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus of the subject matter described herein can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). 
         [0043]    Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processor of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks, (e.g., internal hard disks or removable disks); magneto-optical disks; and optical disks (e.g., CD and DVD disks). The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry. 
         [0044]    To provide for interaction with a user, the subject matter described herein can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, (e.g., a mouse or a trackball), by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, (e.g., visual feedback, auditory feedback, or tactile feedback), and input from the user can be received in any form, including acoustic, speech, or tactile input. 
         [0045]    The subject matter described herein can be implemented in a computing system that includes a back-end component (e.g., a data server), a middleware component (e.g., an application server), or a front-end component (e.g., a client computer having a graphical user interface or a web browser through which a user can interact with an implementation of the subject matter described herein), or any combination of such back-end, middleware, and front-end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet. 
         [0046]    It is noted that one or more references are incorporated herein. To the extent that any of the incorporated material is inconsistent with the present disclosure, the present disclosure shall control. Furthermore, to the extent necessary, material incorporated by reference herein should be disregarded if necessary to preserve the validity of the claims. 
         [0047]    To the extent certain functionality or components “can” or “may” be performed or included, respectively, the identified functionality or components are not necessarily required in all embodiments, and can be omitted from certain embodiments of the invention. 
         [0048]    Further, while the description above refers to the invention, the description may include more than one invention.