Patent Application
20210302260
The mechanical integrity of a building structure can be severely compromised by water infiltration, and the health of building occupants may be negatively impacted by the long-term persistence of moisture within occupied spaces due to the accumulation of mold, mildew, etc. Passive methods of leakage and moisture protection inherently carry risk because any evidence of dampness or wetness within a building structure almost always is detected only after the damage has already been done.
Exterior insulation and finish systems (EIFS) are a general class of non-load-bearing building-cladding systems that provides exterior walls with an insulated, water-resistant, finished surface in an integrated composite material system. EIFS first gained use in North America during the 1960s and grew in popularity because of the energy crisis of the 1970s, but water-infiltration problems in early EIFS resulted in costly litigation. This led to the development of drainable EIFS with a drainage plane located behind the insulation layer to prevent the build-up of excessive moisture within the system. Drainable EIFS is superior to traditional stucco and face-sealed EIFS in terms of mitigating the moisture that infiltrates the exterior cladding of a building.
Excess moisture build-up within the EIFS system can lead to the formation of mold and fungus that could result in a so-called ‘sick building’ creating a health hazard to the occupants. Drainable EIFS solves the moisture-retention issues when the manufacturer's installation instructions and guidelines are followed, but the effectiveness of the drainage plane is still largely dependent upon the skill and competence of the installers, and if done improperly, the EIFS installation may be compromised. In the current art, as represented by commercially-available EIFS systems, once installed, there is no way to check whether the EIFS drainage plane is functioning correctly. This is a glaring weakness in current-art EIFS systems.
Moisture may build-up within the cladding and structure materials if the function of the EIFS drainage plane is compromised either by poor installation practices that clogs the drainage channels with excessive adhesives, or by foreign material that clogs the drainage channels, or by excessive water infiltration through the EIFS cladding that can occur from poor workmanship and/or materials. This is especially true along joints formed by decks and roofing, and at fenestrations from windows and doors. Since the introduction of drainable EIFS, the risk of a compromised installation has been shifted away from the manufacturer and towards the installation contractors.
Installation contractors, the installation methods used by those installation contractors, and the materials used for EIFS are imperfect. Therefore, it must be assumed that water will enter every EIFS installation at some point:
Excess moisture that builds-up within the cladding and the underlying structure may damage the underlying structure and cause material deterioration from mold, decay, loss of strength, dimensional instability and corrosion. Excessive moisture may lead to:
Currently, there is no way to easily monitor the drainage plane of an EIFS installation without physically drilling into the cladding to make measurements using a hand-held moisture-measurement instrument. The effectiveness of this method is quite limited because it can only spot-check a few locations within an installation. Typically, this type of measurement is made initially during the inspection of new EIFS installations, or forensically, after moisture damage to the structure has already occurred. The reality of this limitation is reflected by the existence of specific EIFS insurance (see “Why You Should Opt for EIFS Siding,” available at https://www.eima.com/eifs-insurance) that may be purchased by EIFS contractors to cover the potential liability arising from EIFS installations.
In U.S. Pat. No. 7,768,412 to Vokey, a moisture-monitoring system for buildings is described that uses externally-switched moisture-detecting sensors, and a method for isolating the location of a leak and calculating the severity of the water infiltration is also described. However, the Vokey system is discretely applied with a plurality of individual wiring connections to a building structure and is therefore non-intrinsic to the building envelope, necessitating additional effort to install and verify the system's integrity. Furthermore, the Vokey system requires that an external computerized Supervisory Control and Data Acquisition (SCADA) system be installed within the monitored structure to switch the sensors and determine the location and severity of any detected leakage.
What is needed is an improved EFIS that integrates a moisture-sensing device into the insulation panel and uses self-powered, passive wireless RFID technology to read data that represents the state of moisture within the EIFS drainage plane.
The inventive disclosures contained herein are designed to address limitations associated with the buildup of excessive moisture within the EIFS drainage plane. Moisture-sensing elements are integrated directly into the proximal (inward-facing) surface of the insulation board material, and the electronic-nature of the detection technology may allow the improved insulation panel to become ‘smart’ and respond to the presence of water and/or moisture within the drainage plane of the EIFS installation.
In embodiments, the configuration of the improved EFIS installation exists as a stand-alone intrinsic moisture-sensing panel, optimized to accommodate the EIFS installation environment, requiring little to no differences in the installation protocols presently used by the contracting construction trades. A method is also revealed for how the data may be wirelessly and securely acquired from the EIFS insulating panel using passive RFID that requires no internal power source, and then transmitted to a cloud-based application that may be used to perform predictive analytics. The improved moisture-sensing EIFS panel and data acquisition and processing method provides the following advantages:
The moisture-sensing elements is an improvement over the configuration revealed by U.S. Pat. No. 5,648,724 to Yankielun et al. (“Yankielun”) for “Metallic time-domain reflectometry roof moisture sensor,” which prescribes that a transmission-line sensor be embedded within a medium having a dielectric constant that changes in the presence of water. However, the moisture-sensing elements in the present inventive disclosures have been adapted for integration within an insulation board to provide an EIFS insulation panel with stand-alone intrinsic moisture sensing capability.
In an embodiment, the sensing device is a composite membrane in the form of a strip of metalized polymer material placed within a recessed channel on the proximal surface of the insulation panel onto which a moisture-wicking layer has been placed, with another metalized polymer strip placed over the proximal surface of the wicking layer, where the wicking layer between the metalized strips forms a dielectric. The electrical impedance between the two parallel metalized areas of this composite membrane is then used to sense the presence of moisture by measuring the biplanar capacitance, the electrical resistance, or both the biplanar capacitance and electrical resistance. The stack of layers are bonded together through friction-welding or by an adhesive process.
In another embodiment, the layer of wicking material is first placed within a recessed channel on the proximal surface of the insulation panel, and a polymer layer that has two parallel metalized areas is then placed over the proximal surface of the first wicking layer, and over the polymer layer with the two metalized areas, a second wicking layer is placed. The electrical impedance between the two parallel metalized areas of this composite membrane is then used to sense the presence of moisture by measuring the coplanar capacitance, the electrical resistance, or both the coplanar capacitance and electrical resistance.
In other embodiments, there are additional strips of composite membrane in an additional channel or channels with different geometric orientations placed on the proximal surface of the insulation panel. In still another embodiment, the entire plane of the proximal surface of the insulating board is covered by a layer of the composite moisture-sensing membrane.
In most applications, passive ultra-high frequency (UHF) Radio Frequency Identification (RFID) sensor tags are used to excite the capacitive or resistive sensing elements within the composite moisture-sensing membrane to measure the presence of moisture.
In other embodiments, a plurality of discrete passive UHF RFID tags based on resistive/inductive/capacitive (RLC) impedance of the RFID sensor antenna are integrated within the insulating panels. Tags based on RLC impedance make use of specially-designed RFID sensor chips or simply use standard retail RFID chips that are adapted to the dielectric constant of the material that they are installed into. These RLC impedance-based sensor tags do not require direct contact with water to sense the presence of moisture below the membrane. Because of the sensitivity of RLC impedance-based RFID sensor tags to the materials they are installed into, a baseline calibration is needed to calibrate the dry condition of the sensor tags.
In many embodiments, the discrete or panel-integrated RFID sensor tags are used to provide data to determine whether moisture is present within an EIFS drainage plane, and the unique digital code associated with each RFID tag allows the panel where the moisture is detected to be identified, thereby allowing the location of the moisture within an EIFS installation to be determined. This information is wirelessly transferred to an RFID reader and from the reader, in some variations, the data is uploaded directly to a cloud-based application, while in other variations, the data is sent to the internet via a wireless router and then on to the cloud-based application. The cloud-based application is capable of determining and displaying data trends, as well as to perform predictive-analytics using applied statistics and machine-learning-based AI.
These drawings are intended to provide notional configurations and are therefore not drawn to scale.
The inventive disclosures contained herein are designed to address the limitations of current-art EIFS installations, and primarily focus upon an improved insulation panel with an integrated moisture-sensing channel, thereby providing state-of-the-art EIFS installations with intrinsic moisture-sensing capability for the drainage plane. Generally, one or more moisture-sensing elements are integrated directly into the proximal (inward-facing) surface of insulation-board material, and the electronic-nature of the detection technology allows the improved insulation panel to become ‘smart’ and respond to the presence of water and/or moisture within the drainage plane of the EIFS installation using capacitive and/or resistive sensing methods.
In one embodiment, the capacitive-sensing device is a composite membrane in the form of a strip of metalized polymer material placed within a recessed channel on the proximal surface of an insulation panel onto which a hydrophilic moisture-wicking layer is placed, with another metalized polymer strip placed over the proximal surface of the wicking layer, wherein the wicking layer between the metalized strips forms a capacitive dielectric. Because water has a much higher dielectric constant than the wicking-layer material, when such moisture is present within the insulation panel, the capacitance of the sensing device is increased by an order-of-magnitude or more, enabling the detection of the moisture through electronic means. The change in biplanar capacitance of this composite membrane can then be used to sense the presence of moisture. Typically, the stack of layers is bonded together through friction-welding or by an adhesive process with low mobility of the adhesive into the wicking layer.
In another embodiment, the layer of wicking material is first placed within a recessed channel on the proximal surface of the insulation panel, and a polymer layer that has two parallel metalized areas is then placed over the proximal surface of the first wicking layer, and over the polymer layer with the two metalized areas, a second wicking layer is placed. The electrical impedance between the two parallel metalized areas of this composite membrane can then be used to sense the presence of moisture by measuring the change in coplanar capacitance, or the change in electrical resistance, or both the change in coplanar capacitance and the change in electrical resistance.
In other embodiments, there are additional strips of composite membrane in an additional moisture-detection channel or channels with different geometric orientations that are placed on the proximal surface of the insulation panel. The orientation of the moisture-detection channels is selected to take advantage of the downward movement of moisture by gravity within the EIFS drainage plane.
In yet another embodiment, the proximal surface of the improved panel has pre-formed drainage channels and one or more moisture-detection channels with different geometric orientations that are placed on the proximal surface of this insulation panel. As before, the orientation of the moisture-detection channels is selected to take advantage of the downward movement of moisture by gravity within the EIFS drainage plane. In variations, the entire plane of the proximal surface of the insulating board is covered by a layer of the composite moisture-sensing membrane.
In an embodiment, the base membrane of the composite moisture-sensing membrane is formed from high-density polyethylene (HDPE) onto which a metalized layer formed by a vacuum metal deposition (VMD) process is created. The wicking layer can be comprised of a thin membrane of polypropylene/polyethylene (PP/PE), or of a layer of untreated tightly-woven untreated nylon fabric, or of any other hydrophilic porous membrane or moisture-wicking fabric material. In typical variations, the metalized layers over the wicking layer are formed through the VMD process of metal onto a thin carrier membrane that is made of a polymer material such as biaxially oriented polyethylene terephthalate (BoPET) film.
In other embodiments, the proximal surface of the composite moisture-sensing membrane may be covered by a semi-permeable Nafion™ perfluorosulfonic acid (PFSA) membrane that may allow the amount of base coat material present in the EIFS drainage plane to be better detected by the composite moisture-sensing membrane.
The stack of layers may be bonded together through a friction-welding process or with an adhesive that exhibits low mobility into the wicking layer during the curing process.
In other embodiments, a plurality of discrete passive ultra-high frequency (UHF) RFID (Radio Frequency Identification) tags based on resistive/inductive/capacitive (RLC) impedance of the RFID-sensor antenna is integrated within the insulating panels. RFID tags based on RLC impedance make use of specially-designed RFID-sensor chips or simply use standard retail RFID chips that are adapted to the dielectric constant of the material they are installed into. These RLC impedance-based sensor tags do not require direct contact with water in order to sense the presence of moisture below the membrane. Because of the sensitivity of RLC impedance-based RFID-sensor tags to the materials they are installed into, a baseline calibration is needed to calibrate the dry condition of the sensor tags.
Passive UHF RFID tags are used to excite the capacitive or resistive sensing elements within the composite moisture-sensing membrane to measure the presence of moisture. In some embodiments, since the insulation panels are not restricted by area, the RFID dipole antennas can be made much larger than normally seen with UHF tags, thereby extending reading ranges.
The capacitance or resistive sensor integrated into the insulation panel are used to provide the RFID tag with data to determine whether moisture is present within an EIFS drainage plane, and the unique digital code associated with each RFID tag allows the panel in which the moisture is found to be identified, thereby allowing the location of the moisture within an EIFS installation to be determined. This information can be wirelessly transferred to and from an RFID reader. In some embodiments, the data is uploaded directly to a cloud-based application, while in other embodiments, the data is sent to the Internet via a wireless router and then on to the cloud-based application.
The initial installation of the improved moisture-sensing installation panels within an EIFS installation typically requires that the installation topography (moisture-reading, RFID-tag ID, and physical location) to be mapped, and this is accomplished using an RFID reader in association with a surveyor-quality differential Global Positioning System (GPS) Global Navigation Satellite System (GNSS) device. In some variations, the installation topography is mapped manually using a hand-held RFID reader and differential GPS device, while in other variations, the installation topography is mapped using either a flying drone equipped with a high-resolution camera or video feed to carry the RFID reader. In all cases, at the time of installation, data related to the installation (such as the GPS coordinates of the RFID tag, the structure the tag is installed upon, and the identity of the installing contractor) is written to the RFID tag's non-volatile memory and protected by an encryption password using the RFID reader. Finally, the cloud-based application can display data trends and performing predictive-analytics using applied statistics and machine-learning-based Artificial Intelligence (AI).
The terms and phrases as indicated in quotes (“ ”) in this Section are intended to have the meaning ascribed to them in this Terminology Section applied to them throughout this document, including the claims, unless clearly indicated otherwise in context. Further, as applicable, the stated definitions are to apply, regardless of the word or phrase's case, to the singular and plural variations of the defined word or phrase.
The term “or”, as used in this specification, drawings, and any appended claims, is not meant to be exclusive; rather, the term is inclusive, meaning “either or both”.
References in the specification to “one embodiment”, “an embodiment”, “a preferred embodiment”, “an alternative embodiment”, “other embodiments”, “another embodiment”, “a variation”, “one variation”, and similar phrases mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an embodiment of the invention. The appearances of the phrase “in one embodiment”, “in one variation”, and/or similar phrases in various places in the specification are not necessarily all meant to refer to the same embodiment.
The term “couple” or “coupled”, as used in this specification, drawings, and any appended claims, refers to either an indirect or a direct connection between the identified elements, components, or objects. Often the manner of the coupling will be related specifically to the manner in which the two coupled elements interact.
The term “removable”, “removably coupled”, “readily removable”, “readily detachable”, “detachably coupled”, and similar terms, as used in this specification, drawings, and any appended claims, refer to structures that can be uncoupled from an adjoining structure with relative ease (i.e., non-destructively and without a complicated or time-consuming process) and that can also be readily reattached or coupled to the previously adjoining structure.
The terms “transverse” and “longitudinal” as used in this specification, drawings, and any appended claims, respectively refer to the short or widthwise dimension of a membrane, and the long or lengthwise dimension of a membrane. The transverse direction (TD), when used with a membrane or panel, refers to the direction across the short dimension. The longitudinal direction (LD), when used with a membrane or panel, refers to the direction along the long dimension. The LD also refers to the so-called “machine” direction (MD), which is the direction a roll is processed (unrolled and/or rolled) during the manufacturing process.
As used in this specification, drawings, and any appended claims, directional and/or relational terms such as, but not limited to, left, right, nadir, apex, top, bottom, vertical, horizontal, back, front, lateral, proximal, and distal are relative to each other, are dependent on the specific orientation of an applicable element or article, are used accordingly to aid in the description of the various embodiments, and are not necessarily intended to be construed as limiting in this specification, drawings, and any appended claims.
Similarly, as used in this specification, drawings, and any appended claims, the terms “over” and “under”, are relative terms. For example, the improved moisture-sensing membrane strip is positioned “over” the proximal surface side of the insulation panel because the proximal surface side is designated as the surface nearest to the structural substrate.
The terms “discrete” and “integrated” are used to associate the relationship of the moisture-sensing elements with their installation panels. “Discrete” implies that the sensing elements act as stand-alone sensors within a panel installation, while “integrated” implies that the sensing elements are part of the installation panel and therefore act in conjunction with the installation panel.
As applicable, the terms “about” or “generally” or “approximately”, as used herein unless otherwise indicated, means a margin of +/−20%. Also, as applicable, the term “substantially” as used herein unless otherwise indicated means a margin of +/−10%. The terms “nominal” and “nominally” are used to indicate dimensions within a margin of +/−5%. The terms “reference” or “reference value” refer to non-critical dimensions or characteristics. The terms “typical” or “typically” refer to methods, compositions, or dimensions used in current-art and/or commercially available applications (including when current-art and/or commercially available applications are incorporated in the improved applications described herein). It is to be appreciated that not all uses of the above terms are quantifiable such that the referenced ranges can be applied.
This Section III is directed to an improved EFIS with intrinsic moisture-sensing capabilities for use in building structures, such as vertical wall cladding structures that are disposed above ground. Refer to
Refer to
Over the distal surface of the installed improved insulating panel 1, basecoat 9 is coated over a strengthening mesh 8, and this is in turn covered with the final finishing coat 10 to create a relatively lightweight-yet-strong exterior finish for the building. The basecoat 9, strengthening mesh 8, and final finishing coat 10 are depicted partially removed to reveal keep-away-zones 3 that, in variations, are stenciled into the distal surface of improved insulating panel 1 that indicate where the moisture-sensing channels 2 are located on the proximal side of improved insulating panel 1. Keep-away-zones 3 provide indications to installing contractors where mechanical fasteners should not be driven through improved insulating panel 1 in order to avoid damaging the moisture-sensing-channel 2 elements.
The embodiment of the improved moisture-sensing insulation panel 1 depicted in
Another embodiment of the improved moisture-sensing insulation panel 1A is isometrically depicted in
Refer now to
Wicking layer 18 of thickness tD can be formed from a hydrophilic layer of PE/PP with a thickness tD of approximately 10 to 20 mils; however, this dimension can vary depending on the application and configuration of moisture-sensing channel 2. Alternatively, wicking layer 18 can be composed of untreated (i.e., there are no water-repellant chemical additives) nylon 70-denier fabric with a taffeta weave, or other finely woven pattern, with a thickness tD of approximately 13 mils. The untreated nylon exhibits hydrophilic wicking behavior with moisture. Notably, untreated nylon fabric is often used as a liner for sports equipment or clothing to wick perspiration away from an athlete's skin. It should be recognized for those skilled in the art that the wicking layer 18 can be composed of any porous hydrophilic material with appropriate dimensional, chemical, and thermal properties that can facilitate its function as a dielectric material that varies with water content and conforms to the intended environmental and installation applications. Wicking layer 18 is attached to the metalized coating 17 using any low volatile organic compound (VOC) adhesive with low mobility into wicking layer 18 during the curing process. A sensing membrane 19 of width x1 is attached to the proximal surface of wicking layer 18 using any low VOC adhesive with low mobility into wicking layer 18. Sensing membrane 19 has a sandwiched metalized layer 20 formed by a VMD with the same characteristics as metalized layer 17. The covering layers over sandwiched metalized layer 20 of sensing membrane 19 are typically composed of BoPET film, where overall thickness tE of sensing membrane 19 may be approximately 8 mils or less. For capacitance measurements, the edges of the sandwiched metalized layer 20 must be completely sealed by the covering layers of sensing membrane 19 so that metalized layer 20 may not electrically contact the water in the wicking layer 18. Gaps of distance d2 are left between the outer edges of sensing membrane 19 and the walls of moisture-sensing channel 2 to allow water or moisture within the EIFS drainage plane to contact wicking layer 18. Gap width d2 may be approximately 100 to 200 mils, depending on the configuration of the moisture-sensing channel 2 and the sensing membrane 19. The covering layers of sensing membrane 19 may be composed of any polymer or fluoropolymer material with mechanical and chemical properties conforming to the intended environmental and installation applications. A covering layer of semi-permeable membrane 21 may be placed over the proximal surface of the composite moisture-sensing membrane (detection device) residing within moisture-sensing channel 2 and may be composed of PFSA with thickness tF, where tF may be vary between approximately 100 and 300 microns (about 4 to 12 mils). The PFSA material of covering semi-permeable membrane 21 is also used as membrane in proton exchange membrane (PEM) fuel cells, which allows water and ions to pass but no other larger molecules, and therefore this property of semi-permeability may be useful to help the detection device within moisture-sensing channel 2 sense the presence of basecoat material 5 in contact with the proximal surface covering semi-permeable membrane 21. The amount of contacting basecoat material 5 may provide an indication about the quality of the drainage plane configuration, because excess basecoat material 5 may clog the EIFS drainage plane, while excessively sparse basecoat material 5 may result in poor adhesion with the improved moisture-sensing insulating panel 1 or 1A. Typical uptake of water through the PFSA layer is 38% and typically occurs over a 1-hour period as measured by ASTM D570. Temperature will affect the uptake rate, where the rate increases with increasing temperature. Uptake rate may be improved by introducing small perforations (around several microns in diameter) into the semi-permeable membrane 21, in which case, a conventional polymer membrane material such as BoPET may be possible to use instead of PFSA. It must be noted that because the EIFS drainage plane (depending on climate and installation) may experience dramatic cyclic swings in moisture content; therefore, it is critical that the moisture detecting element be resistant to ionic contamination that can introduce electrically-conductive residues to the moisture-sensing element wicking layer 18, and thereby impart a resistance change to the sensing element, even after the moisture within the EIFS drainage plane subsides and becomes completely dry. The semi-permeable membrane covering layer 21 is intended to provide this resistance to ionic contamination.
The composite moisture-sensing membrane that forms the detection device within moisture-sensing channel 2 may therefore be composed of a plurality of adhesively-attached layers and materials as described previously, with an overall thickness of tC+tD+tE+tF or approximately 25 to 45 mils, depending on the configuration. The strength of the adhesive bonds between layers should be sufficient to allow the improved moisture-sensing insulating panels 1 or 1A to be stored, transported and moved into place on the jobsite during installation. The bonding adhesives should be chemically compatible with the materials of the various layers and should be capable of withstanding the environmental conditions of the EIFS installation (ambient temperature extremes and moisture). Alternatively, a mechanical friction-welding process may be used to bond the various layers together instead of adhesive or may be used in combination with adhesives to bond the various layers together. The bond strength of the various layers of the sensing device within moisture-sensing channel 2 should be sufficient to allow the panel to be cut-to-size in the field during installation without tearing or delaminating the various layers from the underlying insulating materials. A removable paper or silicone release liner (not depicted) may be adhered to the proximal surface of the improved moisture-sensing insulating panels 1 or 1A to serve as protection for the detection device within the moisture-sensing channels 2 until the release liner is removed prior to installation. It may also be beneficial to introduce a factory-applied mastic sealant to the longitudinal edges of the sensing elements at location 16, or in the field when cuts are made, to protect the sensing element longitudinal ends from ionic contamination.
For capacitance measurements, the edges of the sandwiched metalized layer 20 must be completely sealed so that metalized layer 20 does not electrically contact the water in the wicking layer 18, 18A. For resistance measurements, the edges of the sandwiched metalized layer 20 can be left partially exposed, or either one of the upper or lower covering layers of sensing membranes 19A, 19B can be eliminated. Another wicking layer 18A, also of thickness tD, can be bonded over sensing membranes 19A, 19B using any low-VOC adhesive with low mobility into wicking layer 18A. The covering layers of sensing membranes 19A, 19B are composed of any polymer or fluoropolymer material with mechanical and chemical properties conforming to the intended environmental and installation applications. Gaps of distance d2 are left between the outer edges of sensing membranes 19A, 19B and the walls of moisture-sensing channel 2A. Gap width d2 is approximately 100 to 200 mils, depending on the configuration of the moisture-sensing channel 2A and the sensing membrane 19, and separation gap d3 is 50 to 100 mils, depending on the electrical characteristics desired (i.e., lowering the dimension of gap d3 will increase coplanar capacitance, but if gap d3 is too narrow, the resistance sensitivity might become too great to be effective). As with the
The amount of contacting basecoat material 5 provides an indication about the quality of the drainage plane configuration, because excess basecoat material 5 can clog the EIFS drainage plane, while excessively sparse basecoat material 5 can result in poor adhesion with the improved moisture-sensing insulating panel 1, 1A. Typical uptake of water through the PFSA layer is 38% and typically occurs over a one-hour period as measured by ASTM D570. Temperature affect the uptake rate, where the rate increases with increasing temperature. Uptake rate can be improved by introducing small perforations (around several microns in diameter) into the semi-permeable membrane 21, in which case a conventional polymer membrane material such as BoPET is possible to use instead of PFSA. It must be noted that because the EIFS drainage plane (depending on climate and installation) can experience dramatic cyclic swings in moisture content, it is critical that the moisture-detecting element be resistant to ionic contamination that can introduce electrically-conductive residues to the moisture-sensing element wicking layers 18, 18A, and thereby impart a resistance change to the sensing element, even after the moisture within the EIFS drainage plane subsides and becomes completely dry. The semi-permeable membrane covering layer 21 is intended to provide this resistance to ionic contamination.
The composite moisture-sensing membrane that forms the detection device within moisture-sensing channel 2A can, therefore, be composed of a plurality of adhesively-attached layers and materials as described previously, with an overall thickness of 2tD+tE+tF, or approximately 30 to 50 mils, depending on the configuration. The strength of the adhesive bonds between layers should be sufficient to allow the improved moisture-sensing insulating panels 1, 1A to be stored, transported, and moved into place on the jobsite during installation. The bonding adhesives should be chemically compatible with the materials of the various layers and should be capable of withstanding the environmental conditions of the EIFS installation (ambient temperature extremes and moisture). Alternatively, a mechanical friction-welding process can be used to bond the various layers together instead of adhesive or can be used in combination with adhesives to bond the various layers together. The bond strength of the various layers of the sensing device within moisture-sensing channel 2A should be sufficient to allow the panel to be cut-to-size in the field during installation without tearing or delaminating the various layers from the underlying insulating materials. A removable paper or silicone release liner (not depicted) is adhered to the proximal surface of the improved moisture-sensing insulating panels 1, 1A to serve as protection for the detection device within the moisture-sensing channels 2A until the release liner is removed prior to installation. It may also be beneficial to introduce a factory-applied mastic sealant to the longitudinal edges of the sensing elements, or to introduce a mastic sealant in the field when cuts are made, in order to protect the sensing-element longitudinal ends from ionic contamination.
The wireless RFID tags 22 depicted in the embodiments of
Any moisture present in the drainage plane contacts the detection device within the moisture-sensing channels 2, 2A and is drawn into wicking layer 18A and/or wicking layer 18 through gaps d2 and/or separation gap d3. The porous material of the wicking layers 18, 18A have a relative permittivity (i.e., dielectric constant) of approximately 1.5 to 2.4 for polymer materials (polyethylene 2.2 to 2.4; see, e.g., http://www.clippercontrols.com/pages/Dielectric-Constant-Values.html#P) and approximately 3 to 5 for nylon (nylon 4.0 to 5.0, or nylon resin 3.0 to 5.0; see, e.g., http://www.clippercontrols.com/pages/Dielectric-Constant-Values.html#N), while water has a relative permittivity of 80.2 at 68° F. (20° C.); therefore, between the dry and wet states of wicking layers 18, 18A, both the biplanar capacitance between sandwiched metalized layer 20 of sensing membrane 19 and metalized coating 17, and the coplanar capacitance between adjacent sandwiched metalized layers 20 of sensing membranes 19A, 19B, may change by a factor of 20 to 50 (greater than one order of magnitude), allowing an external electronic measurement device to readily detect the presence of any water absorbed into wicking layers 18, 18A within the detection device residing in moisture-sensing channels 2, 2A. Electrical resistance between sensing membranes 19A and 19B configured for resistance measurements is altered by the presence of water within wicking layers 18, 18A. The advantage of a resistance-based measurement is that a simpler electronic measurement method can be performed by wireless RFID tag 22; however, but the disadvantage of relying one a resistance-based measurement is the need to eliminate the covering semi-permeable membrane 21 in order to allow electrically-conductive ionic compounds within the moisture to be carried into the wicking layers 18, 18A, which also serves to make the resistance measurement inoperative if these electrically-conductive ionic compounds remain as residue within wicking layers 18, 18A when the moisture evaporates. The resistance-based measurement can also be insensitive to the presence of base coat 5 that can be in contact with the sensing device within moisture-sensing channel 2A. It should be noted that capacitive-based measurements may not be sensitive to electrically-conductive ionic compounds that remain as residue within wicking layers 18, 18A.
For vertical proximal surface EIFS installations of the
For vertical proximal surface EIFS installations of the
The factory-integrated nature of the improved moisture-sensing insulating panels 1, 1A of various configurations are ideally suited for prefabricated EIFS panels, where the EFIS panels are custom-fabricated for an installation within a factory setting. These completed EFIS panels are then transported to the jobsite and installed, saving time, and reducing the installation variation and compromised quality that often arises during a direct installation by a contractor at a jobsite. A commercial example of a prefabricated EIFS panels is the Dryvit Tech21® prefabricated panel program (see, e.g., http://www.dryvit.com/our-solutions/panelization/).
Now refer to
Biplanar capacitance yields a large change in capacitance when wicking layer 18 absorbs moisture. Coplanar capacitance yields a smaller magnitude of capacitance, but still may experience a large relative change in capacitance when wicking layers 18 and 18A absorb moisture.
Biplanar capacitance Cbp in Farads is defined as shown in Equation [1] below:
Where:
For the calculations in Table 1, the percent fill of wicking layer 18 was set to 25%, which yielded an εr wet value of 60 with εr water=80.2. The difference in biplanar capacitance is approximately 30 times between a completely dry wicking layer 18 and a fully saturated wet wicking layer 18. This large change in biplanar capacitance between dry and wet conditions provides very good electrical-measurement sensitivity for detecting the presence of moisture in wicking layer 18.
Coplanar capacitance Cep in Farads is defined as shown in Equation [2] (see also, Clayton R. Paul, “Analysis of Multiconductor Transmission Lines,” 2nd Ed., 2008):
Where:
For the calculations in Table 2, the percent fill of wicking layers 18 and 18A was set to 25%, which yielded an εr wet value of 60 with εr water=80.2. A symmetrical wicking layer above and below sensing areas 19A and 19B was assumed. The difference in coplanar capacitance is approximately 30 times between completely dry wicking layers 18 and 18A and fully saturated wet wicking layers 18 and 18A. Although the coplanar capacitance levels are around two orders-of-magnitude less than the equivalent biplanar capacitance values shown in Table 1, the large change in coplanar capacitance between dry and wet conditions still provides very good electrical-measurement sensitivity for detecting the presence of moisture in wicking layers 18 and 18A.
Capacitator voltage Vcap while charging and discharging is defined as shown in Equation [3] below:
This Section IV is directed to an improved method of installing an improved moisture-sensing insulation panel for use in a building structure, and an improved method of detecting and locating post-installation leaks in the building structure. Refer to
Referring to
Typically, the wireless and passive RFID tags 22 use transceiver components that do not require an internal power supply such as a battery and are instead powered from the energy of the reading signal. The RFID tags 22 allows user data to be both read and written to a memory location within each RFID tag 22. In variations, the RFID tag 22 has the capability to encrypt the information stored within its memory locations to prevent the unauthorized deletion, overwriting, or any other malicious or unintentional modification of the RFID tag 22 data and information. Additionally, blockchain cryptographic hash can be used, which ensures that the collection, storage, and readout of the data is secure by design, thereby enabling trust that the data has not been tampered with.
In most embodiments, the RFID tag 22 has the capability to be read passively from a distance greater than 10 feet. In one embodiment, the RFID tag 22 is an Electronic Product Code (EPC) Class 3 Gen 2 Version 2 ISO 18000-6C-Compliant RFID tag and is be Pb-Free, Halogen Free/BFR Free, and RoHS-compliant for environmental responsibility. EPC tags operate in the ISM (Industrial Scientific and Medical) UHF 902-928 MHz band for passive remote sensing and require no installed batteries or power sources, and instead scavenge power only from the radio-frequency (RF) energy of the reading devices and then communicate back to the reader during this time using backscatter. An EPC Class 3 tag has read-write capability with onboard sensors capable of recording external parameters. An EPC Generation 2 tag has four banks of non-volatile memory (Reserved Memory, EPC Memory, Tag Identification—or TID Memory, and User Memory). Finally, Version 2 of the EPC Gen 2 standard includes built-in 128-bit data encryption that allows a proprietary reading protocol to be established (i.e., the tags described herein can only communicate with RFID readers that are equipped with the proper decryption protocols).
In most embodiments, the RFID tags 22 Class 3 sensory capability includes temperature and several additional sensor interfaces that can be configured for the sensory application, such as measuring capacitance, currents, or voltage levels. An example of an EPC Class 3 sensory tag chip that can be used is the AMS SL900A, with an on-board ±0.5° C. temperature measurement sensor that can read across a −40° C. to +125° C. range, and with interfaces for up to two additional sensors external to the chip. The SL900A chip includes a driver voltage and references capacitor location to measure capacitive-based sensors. The reference capacitor used for the SL900A chip would take the place of the load resistors Ra and Rb depicted in
Generic longevity specifications for Gen-2 chips are 40 to 50 years of data retention and 100,000 write cycles. Gen-2 tags can have a read range of over 16 meters or 52 feet when using the full 4-Watt Effective Isotropic Radiated Power (EIRP) legally allowed on the readers by the FCC and other global regulators. Range can be effectively extended for UHF Gen-2 tags by increasing the size of the dipole antenna array. Typically, to save space, Gen-2 tags are restricted to a size that approximates a credit card, or approximately 4 inches in length, which equates to a ¼-wavelength dipole antenna. The wavelength of a 1 GHz signal is approximately 12 inches. It should be noted that 1 GHz is near the UHF 902-928 MHz band or the 0.902-0.928 GHz wavelength. Because the size restriction might not be as important for EIFS applications, the wireless RFID tags 22 can have full-wavelength dipole antennas, and four times (or more) the effective antenna array area over ¼-wavelength dipole antennas. This theoretically doubles the reading range to around 100 feet, because the RFID readers 29, 32, and 33 act as point sources, where the reader's radiated power decreases as an inverse-square of the distance between the reader and the tag. Reading range can also be increased by placing a reflective-metalized-conductive layer immediately under the installed wireless RFID tags 22, as described for metalized coating 24 in
The actual reading distances may be dependent upon insulation panel 1 thicknesses and cladding materials 8, 9, and 10; the reading angles; and the presence of any line-of-site obstructions, including water, snow, and ice. Furthermore, there is an upper limit to how large a wireless RFID tag 22 antenna can become due to parasitic-impedance losses from stray capacitance and inductance that can negatively impact the ability of the RFID chip to drive the antenna signal. Therefore, each EIFS installation requires a different approach to obtain complete reading coverage across the entire area of the building structure.
In variations, a handheld RFID reader 32 that also has a differential GPS device 31 can be used to obtain wireless RFID tag 22 information, as described above, for the drone 28 survey method. Again, as with the drone 28 method 29B, a handheld RFID reader 32 can be limited below full EIRP due to the limited battery power in the handheld RFID reader 32. A handheld-based wireless RFID tag 22 is considered as semi-continuous monitoring, with the frequency of monitoring set by the time interval between handheld-based surveys.
A permanent fixed RFID reader or readers 33 can also be used to obtain wireless RFID tag 22 information, as described previously for the drone 28 method 29B. Distance d4 between fixed RFID readers 33 is established based on the reading range of the fixed RFID readers 33. Unlike portable RFID readers 29 and 32, which may have limited power, a fixed RFID reader 33 can be powered locally from structure power, or from a battery pack that is recharged continuously with outside solar cells or other source; therefore, the full EIRP is available, which allows for the maximum possible passive wireless RFID tags 22 reading range and a continuous monitoring of data within the EIFS installation. The quantity of fixed RFID readers 33 needed to provide full reading coverage is dependent on the practical RFID reading range, the dimensions of the structure with the EIFS installation, the available reading angles, and whether any obstacles are present such as trees and other buildings.
Data can be uploaded directly to a cloud-based application 34 by the drone 28, handheld reader 32, and fixed reader 22 using an onboard 4G or 5G wireless cell connection, or the data can be relayed to another point where it may be uploaded to the cloud-based application 34. In many embodiments, the cloud-based application 34 can perform analysis on the data to generate trend charts and statistical process-control charts, and to perform predictive analytics using applied statistics and Artificial Intelligence (AI)-based machine-learning algorithms. The AI algorithms can be used to predict whether an EIFS installation could soon suffer build-up of excessive moisture so that preventative measures can be timely taken before damage to the underlying structure occurs. The cloud-based application 34 can also augment the database with weather conditions encountered by each EIFS installation in order to help correlate the data obtained from the wireless RFID sensors with actual weather conditions encountered so that prediction capabilities are enhanced. The information from the cloud-application 34 can be available through a wireless application running on a smart phone 35 or through another remote computing device such as a tablet or computer. Furthermore, the cloud-based application 34 uses aggregate data from all EIFS installations uploading data in order to improve the leak-prediction capabilities of the AI-based algorithms.
When handheld RFID reader 32 detects a wireless RFID tag 22 immediately under improved moisture-sensing insulating panel 1, or even within a fully-clad EIFS installation, differential GPS device 31 records the location with high precision. This precision is typically within 25 cm horizontally and 50 cm vertically using an internal antenna. An example of a surveyor-quality differential GPS GNSS handheld device that can be used is the Trimble Geo 7X Handheld (see https://geospatial.trimble.com/products-and-solutions/geo-7x) with an external fixed antenna reference. The unique digital ID, temperature, and capacitance readings from wireless RFID tag 22 as captured by RFID reader 32, and precise location information from differential GPS device 31, including photos or video records, can then be either stored in the memory of differential GPS device 31, or the data can be relayed to a local computer-storage device, or the data can be uploaded to the cloud application 34. When all wireless RFID tag 22 within the EIFS installation have been located, read, and mapped (tag's unique digital ID associated with precision differential GPS location), the topographical mapping of the EIFS installation will have been completed. This topographical mapping operation may only need to be performed once immediately after installation of the EIFS. The data from each wireless RFID tag 22 allows the initial improved moisture-sensing insulation panel 1/1A readings of the EIFS installation to be normalized by referencing all future readings to this baseline (also referred to as a calibration tare). Any future improved moisture-sensing insulation panel 1/1A readings that depart from the baseline will be obvious when tracked over time. An initial-installation verification can then be performed by ensuring that no improved moisture-sensing insulation panels 1/1A depart statistically from the initial baseline. Any wireless RFID tags 22 readings with departures from the baseline that are statistically significant, are flagged as “Out-of-Family” (OOF) and warrant further investigation. OOF readings upon initial-installation verification can be caused by improperly installed insulation panels from either too much or too little basecoat 5 used to bond the improved moisture-sensing insulation panels 1/1A to the barrier membrane 4.
The handheld topographical mapping of an EIFS installation can be used for smaller structures of <10 kSQF. As an example, assuming improved moisture-sensing insulation panels 1/1A of 2×4 feet (or 8-SQF each), 10 kSQF implies around 1000 moisture-sensing insulation panels 1/1A panels, assuming that 25% of the surface area would be doors, windows, and other openings in the building structure. Therefore, it may be more-effective to perform the installation verification jointly with the installation process, or an installation verification immediately after each section of EIFS has been completed. It is also be possible to mount the RFID reader 32 with directional reading shield 32A, differential GPS device 31, and cameras or video-recording devices on a vehicle and drive slowly around the perimeter of a building structure. However, this methodology would only be effective for structures that are no more than two stories in height because of the range limitations of the RFID readers. The directional nature of the initial topographical mapping survey requires that each wireless RFID tag 22 location be precisely known. For topographical mapping surveys by vehicle, it may be possible to use the photographic or video-recording data to rebuild/map the location of each wireless RFID tag 22 visually, but again the directional reading shield 32A would be required to ensure that only one tag is being read at a time. As a result, the practicality of vehicle-based topographical mapping may be limited.
In many embodiments, it is also possible to perform the topographical mapping with a drone 28 using the RFID reader 29 and high-definition camera or video-recording device 30, along with the plurality of bar codes 27 stamped or printed onto the distal side of improved moisture-sensing insulation panels 1/1A. Because each bar code 27 encodes the unique digital ID of the wireless RFID chip 22 contained within the improved moisture-sensing insulation panels 1/1A, the drone-based observation is able to relate its data from each wireless RFID tag 22 reading and correlate this data with the unique digital ID to the bar code 27. This can be accomplished by reading dozens or even hundreds of wireless RFID tags 22 simultaneously within the field of view of the high-definition camera or video-recording device 30. In some cases, it is possible to use the photographic or video-recording data to rebuild/map the location of each wireless RFID tag 22 visually within the cloud application 34 without the need for a differential GPS 31 device. The unique digital ID, temperature, and capacitance readings from wireless RFID tag 22, as captured by RFID reader 32, and precise location information from photos or video records, can be relayed to a local computer-storage device, or the data can be uploaded to the cloud application 34. When all wireless RFID tag 22 within the EIFS installation have been located, read, and mapped (tag's unique digital ID associated with precision differential GPS location), the topographical mapping of the EIFS installation will have been completed.
Because topographical mapping by drone 28 relies on being able to image the plurality of bar codes 27 stamped or printed onto the distal side of improved moisture-sensing insulation panels 1/1A, it is necessary to perform the installation verification while the EIFS installation process is occurring. In this scenario, drone 28 with RFID reader 29 and high-definition camera or video-recording device 30, periodically sweep by the installation contractors as they are placing improved moisture-sensing insulation panels 1/1A in order to obtain wireless RFID tag 22 readings while the plurality of bar codes 27 are visible, prior to the application of the strengthening mesh 8, basecoat 9, and finishing coat 10. Finally, it is possible to print or apply the bar code 27 with a material such as conductive ink or polymers that have a different infrared signature from the base material of improved moisture-sensing insulation panels 1/1A, and/or the bar code 27 can be printed onto raised or recessed areas that have a physical pattern identical with the bar code 27 pattern. In this case, it is possible to obtain the infrared image of the plurality of bar codes 27 through strengthening mesh 8, basecoat 9 and finishing coat 10. The following restrictions would apply for the infrared method described here: (1) The high definition camera or video recording device 30 used for drone 28 with RFID reader 29 must have infrared wavelength capability; (2) The metalized bar code 27 placed on the distal side of improved moisture-sensing insulation panels 1/1A, have to be made as large as possible to improve its infrared detectability; and (3) The metalized bar code 27 placed on the distal side of improved moisture-sensing insulation panels 1/1A have to be placed so as not to interfere with the antenna of wireless RFID tags 22 while the tags are being read.
Finally, some observations and notes must be made for the number of improved moisture-sensing insulation panels 1/1A required for an EIFS installation. Assuming 8-SQF per moisture-sensing insulation panels 1/1A and 25% of a structure's vertical wall area is devoted to doors, windows, and other openings, as well as one wireless RFID tag 22 per improved moisture-sensing insulation panels 1/1A, the number of wireless RFID tags 22 required for a large EIFS installation may become excessive (e.g., approximately 10,000 tags for a 100 kSQF structure). In view of this, the following can be considered to mitigate this situation:
Referring to the method flowchart of
The alternate tag location method 103 may be using a very low RFID reader; e.g., Effective Isotropic Radiated Power (ERIP) or a metalized-directional-reading shield; so that only the closest tag may be read:
Optionally, even when differential GPS location coordinates 108 are available, the visual or directional coordinates 106 can also be written to the non-volatile memory of the RFID tag. The visual or directional coordinates 103 can consist of locating the position of an RFID tag within the installation using a camera or laser rangefinder to determine the distance and angular bearing from pre-surveyed physical datums and/or using a camera to determine the location within a pre-plotted physical grid marked upon the installation. The RFID tag moisture and temperature reading 110 is made after the transponder ID (TID) and tag location have been established.
As the RFID readings continue to be taken, the data for each RFID tag is checked 111 for an Out-of-Family (OOF) reading when compared to all the other RFID tags read.
The installation-verification method depicted in the flowchart of
The installation verification process begins 200 after the EIFS with intrinsic moisture-sensing capability has been installed on a structure and only after the installation topography mapping method of
For OOF readings, SPC and other statistical methods known in the art can be used to help establish the control limits where readings that fall outside the control limits are deemed as OOF. The cloud-based application can be used to calculate and establish the preliminary control limits used for installation-verification checks. Additionally, after many installations have been made and verified, the control limits can be adjusted based on expected normal sensor-tag-reading behavior under installation verification conditions for each type of installation. As an example, the drainage plane of an EIFS installation can be expected to allow moisture to enter under wetted conditions, but the drainage plane will then dry out over time. Therefore, EIFS-panel-moisture readings can be dynamic in nature, with moisture readings that fluctuate with time, and departures from the expected dynamic behavior constitutes an OOF condition.
The various embodiments and variations thereof described herein, including the descriptions in any appended Claims and/or illustrated in the accompanying Figures, are merely exemplary and are not meant to limit the scope of the inventive disclosure. It should be appreciated that numerous variations of the invention have been contemplated as would be obvious to one of ordinary skill in the art with the benefit of this disclosure.
Hence, those ordinarily skilled in the art will have no difficulty devising myriad obvious variations and improvements to the invention, all of which are intended to be encompassed within the scope of the Description, Figures, and Claims herein.
This patent application claims the priority benefit of U.S. Patent Application No. 63/000,606, filed on Mar. 27, 2020, for “RFID-Based Moisture-Sensing and Leak Detection for Building Structures and Methods of Use.” In addition, this patent application hereby incorporates by reference U.S. Patent Application No. 63/000,606. For claim-construction purposes, if there are any irreconcilable differences between the disclosures in the present patent application and U.S. Patent Application No. 63/000,606, then the disclosures of the present patent application shall govern.
| Number | Date | Country | |
|---|---|---|---|
| 63000606 | Mar 2020 | US |
