Device and non-invasive method to determine degradation and thermal properties of single and double glazing

Abstract

In one aspect, the disclosure relates to methods for assessing performance in single glazing units and / or insulated glazing units. In an aspect, the methods include taking at least one photograph of the glazing unit(s) using a full-spectrum digital camera through an integrating sphere, wherein a collimated beam of light exits the integrating sphere and enters the camera lens. In a further aspect, data from a region of interest can then be extracted from the photograph and the extracted data can be baseline corrected and correlated to at least one performance-related property such as, for example, R value or fill gas percentage. Also disclosed are systems used in performing the disclosed methods.

Description

DEVICE AND NON-INVASIVE METHOD TO DETERMINE DEGRADATION AND THERMAL PROPERTIES OF SINGLE AND DOUBLE GLAZINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 63 / 675,325, filed July 25, 2024, which is incorporated herein by reference in its entirety.BACKGROUND

[0002] Buildings account for a substantial portion of global energy consumption, predominantly through heating and cooling requirements. Windows are essential for natural lighting in buildings, which can reduce the need for artificial lighting, as well as enhancing the aesthetic appeal of the buildings and contributing to indoor temperature regulation. Furthermore, windows can be optimized to minimize UV ray penetration, which can reduce occupant health hazards as well as preserve the lifetime of interior furnishings. Windows function as thermal barriers and are major contributors to energy loss, significantly impacting a building’s overall energy efficiency. Windows endure environmental wear and tear, leading to the degradation of window components. Reducing energy loss through windows and glass facades is one way in which the energy efficiency of buildings can be improved.

[0003] Glass degradation alters chemical composition and optical properties of windows, and windows require periodic replacement to maintain energy efficiency. Replacing windows only when needed can result in significant cost savings and reduce waste.

[0004] Current approaches to evaluating fenestration rely on complex instruments such as spectrophotometers, ultrasonic devices, and radiometers. These instruments are immobile and expensive and can be difficult or impossible to deploy in situ for windows installed above ground level. Furthermore, some commercial products have been determined to provide inaccurate results. What is needed is a cost-effective and non-destructive approach to assess long-term performance in both single glazing and double glazing units.

[0005] Despite advances in fenestration evaluation research, there is still a scarcity of methods and devices for evaluating performance and condition of windows in commercial and residential buildings. An ideal method and device would be inexpensive and mobile and could assess both thermal performance of single glazing and argon gas content and thermal properties of double glazing. These needs and other needs are satisfied by the present disclosure.SUMMARY

[0006] In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to methods for assessing performance in single glazing units and / or insulated glazing units. In an aspect, the methods include taking at least one photograph of the glazing unit(s) using a full-spectrum digital camera through an integrating sphere, wherein a collimated beam of light exits the integrating sphere and enters the camera lens. In a further aspect, data from a region of interest can then be extracted from the photograph and the extracted data can be baseline corrected and correlated to at least one performance-related property such as, for example, R value or fill gas percentage. Also disclosed are systems used in performing the disclosed methods.

[0007] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described embodiments are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0009] FIG. 1 shows a cross sectional view of a double glazed window unit. Two parallel glass panes form the inner and outer faces of the window, with a gas mixture such as air, an air-argon mixture, or argon trapped inside. Spacers maintain distance of the two panes from one another as well as capping the top and bottom of the window so that the filling gas does not escape.

[0010] FIG. 2A shows a traditional integrating sphere. Such a sphere creates challenges with scattered, non-collimated light. FIG. 2B shows a custom integrating sphere as disclosed herein with certain design modifications to enhance uniform scattering and consistent light measurement, ensuring reproducibility of measurements.

[0011] FIGs. 3A-3E show image capture without an integrating sphere using neutral density (ND) filters of 100%, 50%, 25%, 12.5%, and 0.1%, respectively. It is noted that light is highly scattered and little useful information is available, especially with 25%, 12.5%, and 0.1% ND filters.

[0012] FIGs. 4A-4E show image capture without a disclosed integrating sphere using neutral density (ND) filters of 100%, 50%, 25%, 12.5%, and 0.1%, respectively. It is noted that light is collimated, with a gradual intensity reduction proportional to the ND filter % in each case..

[0013] FIGs. 5A-5B show, respectively, a sample image collected using a full spectrum digital camera and custom integrating sphere as disclosed and geometric shapes overlaid on the image in order to facilitate data extraction.

[0014] FIGs. 6A-6B show use of ND filters for single glazing applications. FIG. 6A: A series of images were captured using ND filters from ND2 to ND1000, demonstrating a gradational diminution of brightness. Output through the ND filters is linear, with a consistent and proportional decrease in light transmission as filter density increases. FIG. 6B: spectral transmission properties observed through ND filters.

[0015] FIG. 7 shows percentage transmission of an LED light source used in exemplary embodiments across various wavelengths.

[0016] FIGs. 8A-8D show images of the light source with different band pass filters. Images were taken without any glazing samples: The first image is of the light source directly into the camera lens (FIG. 8A), the second image used a visible light only band pass filter to capture an image (FIG. 8B), the third image used an IR-only filter (FIG. 8C), and the fourth image used a UV-only filter (FIG. 8D).

[0017] Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.DETAILED DESCRIPTION

[0018] Clear glass is generally transparent to visible light, which includes wavelengths in the range of from about 380 nm to about 750 nm. The UV rays that pass through glass are typically close to the blue edge of the visible spectrum. Near-infrared (NIR) rays, which are just beyond the red edge of the visible spectrum, also transmit through clear glass but arepartially absorbed. Window glass typically blocks or absorbs UV rays with wavelengths shorter than about 300 nm, or far infrared wavelengths greater than 2500 nm.

[0019] Present methods for analyzing single glazed windows are often focused on isolated wavelength bands, limiting the scope of analysis and thus limiting available information about such parameters including solar heat gain coefficients (SHGC) and visible transmittance (VT). In one aspect, transmittance and / or absorbance of the single glazing unit can be captured by the devices and methods disclosed herein.

[0020] Double glazed windows include two panes of glass separated by a space. Typically, inert gases are used between the panes as they provide better insulation than other strategies such as vacuum or air filling. In one aspect, argon is the most commonly used inert gas for double glazed windows. In a further aspect, argon is readily available and relatively inexpensive. In some cases, krypton can be used. Krypton has better insulating properties than argon and may be used in cold climates or high-performance windows, but is typically expensive enough that its use is somewhat rare.

[0021] In one aspect, disclosed herein is a cost-effective and non-invasive method for assessing window glazing using full-spectrum camera technology. In a further aspect, the disclosed systems and devices accurately measure and record the light's spectral properties through both single and double glazing, overcoming the limitations of conventional methods for assessing fenestration.Methods for Assessing Fenestration Performance

[0022] In one aspect, disclosed herein are methods for assessing performance in a single glazing unit or an insulated glazing unit. In a further aspect, the insulated glazing unit can be a double glazing unit consisting of one or more sheets of clear glass, one or more sheets of low emissivity glass, or any combination thereof. In a still further aspect, the insulated glazing unit can include a fill gas such as air, argon, or a combination thereof. In one aspect, the fill gas can be from about 96% to about 100% argon (v / v).

[0023] In another aspect, the method includes taking at least one photograph of the glazing unit, performing a baseline correction on the at least one photograph, and correlating data from the at least one photograph to at least one performance-related property of the glazing unit. In an aspect, the performance-related property can be a thermal property such as, for example, R value. In another aspect, when the glazing unit is a double glazing unit, the at least one performance-related property can be argon percentage (v / v) of fill gas.

[0024] In any of these aspects, the at least one photograph can be taken with a full spectrum digital camera through an integrating sphere, wherein full-spectrum light enters the integrating sphere and a collimated beam exits the integrating sphere.

[0025] In another aspect, data from the at least one photograph can be one or more pixel intensities extracted from the photograph, wherein the one or more pixel intensities are selected to eliminate pixels representing dispersed light. Exemplary procedures for selecting pixels and pixel intensities are provided in the Examples. In still another aspect, performing the baseline correction includes taking at least one baseline photograph with the full spectrum digital camera through the integrating sphere when no glazing unit is present, extracting one or more baseline pixel intensities from the baseline photograph, and calculating a ratio of the one or more pixel intensities from the at least one photograph taken of the glazing unit to the one or more baseline pixel intensities from the at least one baseline photograph.

[0026] In yet another aspect, data from the at least one photograph represents transmittance of at least a portion of the electromagnetic spectrum through the glazing unit, such as from about 300 nm to about 2500 nm, or wherein the portion of the electromagnetic spectrum includes ultraviolet light, visible light, infrared light, or any combination thereof. In some aspects, a neutral density (ND) filter can be fitted to the camera, such as an ND4 or an ND8 filter. Without wishing to be bound by theory, an ND filter can reduce light intensity coming into the camera without destroying information about spectral intensity in the resultant photograph. However, in an alternative aspects, an ND filter is not used.System for Non-lnvasive Evaluation of Performance of Glazing Units

[0027] In one aspect, disclosed herein is a system for non-invasive evaluation of performance of glazing units, the system including a full spectrum digital camera with at least one lens, an integrating sphere, and a light source, wherein the full-spectrum digital camera is configured to capture an image of a collimated beam of light from the light source after light from the light source passes through the integrating sphere. Further in this aspect, the integrating sphere produces the collimated beam of light from the light source. In some aspects, the system further includes an outlet pipe connecting the at least one lens to the integrating sphere. In an aspect, the outlet pipe can be painted matte black or another dark, opaque color. In another aspect, the interior surface of the integrating sphere can be painted with high-reflective white paint, while the exterior surface of the integrating sphere can be painted with black paint. Without wishing to be bound by theory, painting the integrating sphere in such a way keeps external light from entering the integrating sphere other than at the inlet for the light source, and collimates the light to reduce reflectance.

[0028] In any of these aspects, the light source can be an LED emitting visible light, ultraviolet light, infrared light, or any combination thereof; a full-spectrum light source; the sun; or any combination thereof. In some aspects, the system includes a neutral density (ND) filter on the camera, such as an ND4 or ND8 filter. In an alternative aspect, an ND filter is not used.

[0029] Many modifications and other embodiments disclosed herein will come to mind to one skilled in the art to which the disclosed compositions and methods pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. The skilled artisan will recognize many variants and adaptations of the aspects described herein. These variants and adaptations are intended to be included in the teachings of this disclosure and to be encompassed by the claims herein.

[0030] Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0031] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure.

[0032] Any recited method can be carried out in the order of events recited or in any other order that is logically possible. That is, unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification.

[0033] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, thedates of publication provided herein can be different from the actual publication dates, which can require independent confirmation.

[0034] While aspects of the present disclosure can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and one of skill in the art will understand that each aspect of the present disclosure can be described and claimed in any statutory class.

[0035] It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0036] Prior to describing the various aspects of the present disclosure, the following definitions are provided and should be used unless otherwise indicated. Additional terms may be defined elsewhere in the present disclosure.Definitions

[0037] As used herein, “comprising” is to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more features, integers, steps, or components, or groups thereof. Moreover, each of the terms “by”, “comprising,” “comprises”, “comprised of,” “including,” “includes,” “included,” “involving,” “involves,” “involved,” and “such as” are used in their open, non-limiting sense and may be used interchangeably. Further, the term “comprising” is intended to include examples and aspects encompassed by the terms “consisting essentially of’ and “consisting of.” Similarly, the term “consisting essentially of’ is intended to include examples encompassed by the term “consisting of.

[0038] As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a wavelength,” “a filter,” or “a fill gas,” includes, but is not limited to, mixtures, combinations, series, or ranges of two or more such wavelengths, filters, or fill gases, and the like.

[0039] It should be noted that ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. It will be further understood that the endpoints of eachof the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms a further aspect. For example, if the value “about 10” is disclosed, then “10” is also disclosed.

[0040] When a range is expressed, a further aspect includes from the one particular value and / or to the other particular value. For example, where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g. the phrase “xto y” includes the range from ‘x’ to ‘y’ as well as the range greater than x’ and less than ‘y’. The range can also be expressed as an upper limit, e.g. ‘about x, y, z, or less’ and should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘less than x’, less than y’, and ‘less than z’. Likewise, the phrase ‘about x, y, z, or greater’ should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘greater than x’, greater than y’, and ‘greater than z’. In addition, the phrase “about ‘x’ to ‘y’”, where ‘x’ and ‘y’ are numerical values, includes “about x’ to about ‘y’”.

[0041] It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 0.1% to 5%” should be interpreted to include not only the explicitly recited values of about 0.1 % to about 5%, but also include individual values (e.g., about 1 %, about 2%, about 3%, and about 4%) and the sub-ranges (e.g., about 0.5% to about 1.1 %; about 5% to about 2.4%; about 0.5% to about 3.2%, and about 0.5% to about 4.4%, and other possible sub-ranges) within the indicated range.

[0042] As used herein, the terms “about,” “approximate,” “at or about,” and “substantially” mean that the amount or value in question can be the exact value or a value that provides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art such that equivalent results or effects are obtained. In somecircumstances, the value that provides equivalent results or effects cannot be reasonably determined. In such cases, it is generally understood, as used herein, that “about” and “at or about” mean the nominal value indicated ±10% variation unless otherwise indicated or inferred. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about,” “approximate,” or “at or about” whether or not expressly stated to be such. It is understood that where “about,” “approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0043] As used herein, the terms “optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0044] A “full spectrum camera” as used herein captures the entire solar spectrum. In one aspect, the spectral intensity incident on each pixel depends upon the wavelengths from the solar spectrum incident on the pixel.

[0045] As used herein, “fenestration” refers to the glass elements of a building such as, for example, windows or skylights. Fenestration elements allow light to enter a building and serve a decorative purpose but can also be a source of energy inefficiency if fenestration units start to fail. Provided herein are non-invasive, non-destructive, and inexpensive systems and methods for evaluating fenestration elements to determine such factors as energy efficiency and whether there is a need for repair and / or replacement.

[0046] “Single glazing” or “single glazed” as used herein refers to windows made with a singular pane of glass.

[0047] “Insulated glazing” as used herein refers to a window made with two or more panes of glass, such as double glazed windows, which consist of two panes of glass separated by a gap, wherein the gap contains a fill gas such as, for example, air, argon, or a combination thereof. The two panes of glass can be the same type of glass or can be different types of glass.

[0048] “R value” is a measure of the resistance of heat transfer through glass. In one aspect, a higher R value correlates to better insulation against heat. In another aspect, a decrease in R value in the same window over time may indicate the need to replace the window. In an alternative aspect, if R value stays the same overtime, a window does not need to be replaced. In one aspect, provided herein are systems and methods for assessing properties of fenestration elements such as R value.

[0049] An “integrating sphere” as used herein is a hollow spherical cavity with holes for entrance and exit ports. The interior of the integrating sphere can be covered with a reflective coating. An integrating sphere provides a uniform scattering or diffusing effect.

[0050] A “neutral density filter” or “ND filter” as used herein is a filter for a camera that reduces or modifies the intensity or transmittance of all wavelengths of light equally. ND filters as used herein can be referred to in several different ways but have the same meaning. For example, an ND1000 filter allows a fractional transmittance of about 0.1 %, an ND 8 filter allows a fractional transmittance of about 12.5%, an ND4 filter allows a fractional transmittance of about 25%, and an ND2 filter allows a fractional transmittance of about 50%.

[0051] Unless otherwise specified, temperatures referred to herein are based on atmospheric pressure (i.e. one atmosphere).

[0052] Now having described the aspects of the present disclosure, in general, the following Examples describe some additional aspects of the present disclosure. While aspects of the present disclosure are described in connection with the following examples and the corresponding text and figures, there is no intent to limit aspects of the present disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the present disclosure.ASPECTS

[0053] The present disclosure can be described in accordance with the following numbered aspects, which should not be confused with the claims.

[0054] Aspect 1 . A method for assessing performance of a single glazing unit, the method comprising:(a) taking at least one photograph of the single glazing unit;(b) performing a baseline correction on the at least one photograph; and(c) correlating data from the at least one photograph to at least one performance- related property of the single glazing unit.

[0055] Aspect 2. The method of aspect 1 , wherein the at least one photograph is taken with a full-spectrum digital camera through an integrating sphere.

[0056] Aspect 3. The method of aspect 2, wherein full-spectrum light from a light source enters the integrating sphere and a collimated beam exits the integrating sphere.

[0057] Aspect 4. The method of any one of aspects 1-3, wherein the at least one performance-related property comprises a thermal property.

[0058] Aspect 5. The method of aspect 4, wherein the thermal property comprises R- value.

[0059] Aspect s. The method of any one of aspects 1-5, wherein the data from the at least one photograph comprises one or more pixel intensities extracted from the at least one photograph, wherein the one or more pixel intensities are selected to eliminate pixels representing dispersed light.

[0060] Aspect 7. The method of aspect 6, wherein performing the baseline correction comprises:(a) taking at least one baseline photograph with the full-spectrum digital camera through the integrating sphere wherein no glazing unit is present;(b) extracting one or more baseline pixel intensities from the at least one baseline photograph; and(c) calculating a ratio of the one or more pixel intensities from the at least one photograph taken of the single glazing unit to the one or more baseline pixel intensities from the at least one baseline photograph.

[0061] Aspect 8. The method of any one of aspects 1-7, wherein the data from the at least one photograph represents transmittance of at least a portion of the electromagnetic spectrum through the single glazing unit.

[0062] Aspect 9. The method of aspect 8, wherein the portion of the electromagnetic spectrum is between about 300 nm and about 2500 nm.

[0063] Aspect 10. The method of aspect 8 or 9, wherein the portion of the electromagnetic spectrum comprises ultraviolet light, visible light, infrared light, or any combination thereof.

[0064] Aspect 1 1. The method of any one of aspects 1-10, further comprising using a neutral density (ND) filter on the camera.

[0065] Aspect 12. The method of aspect 1 1 , wherein the ND filter comprises an ND4 or an ND8 filter.

[0066] Aspect 13. A method for assessing performance in an insulated glazing unit (IGU), the method comprising:(a) taking at least one photograph of the IGU;(b) performing a baseline correction on the at least one photograph; and(c) correlating data from the at least one photograph to at least one performance- related property of the IGU.

[0067] Aspect 14. The method of aspect 13, wherein the IGU is a double glazing unit.

[0068] Aspect 15. The method of aspect 13 or 14, wherein the IGU comprises one or more sheets of clear glass, one or more sheets of low emissivity glass, or any combination thereof.

[0069] Aspect 16. The method of any one of aspects 13-15, wherein the IGU comprises a fill gas comprising air, argon, or any combination thereof.

[0070] Aspect 17. The method of aspect 16, wherein the fill gas comprises from about 96% to about 100% argon.

[0071] Aspect 18. The method of any one of aspects 13-17, wherein the at least one photograph is taken with a full-spectrum digital camera through an integrating sphere.

[0072] Aspect 19. The method of aspect 18, wherein full-spectrum light from a light source enters the integrating sphere and a collimated beam exits the integrating sphere.

[0073] Aspect 20. The method of any one of aspects 13-19, wherein the at least one performance-related property comprises a thermal property.

[0074] Aspect 21. The method of aspect 20, wherein the thermal property comprises R- value.

[0075] Aspect 22. The method of any one of aspects 13-21 , wherein the at least one performance-related property comprises argon percentage of fill gas.

[0076] Aspect 23. The method of any one of aspects 13-22, comprises one or more pixel intensities extracted from the at least one photograph, wherein the one or more pixel intensities are selected to eliminate pixels representing dispersed light.

[0077] Aspect 24. The method of aspect 23, wherein performing the baseline correction comprises:(a) taking at least one baseline photograph with the full-spectrum digital camera through the integrating sphere wherein no glazing unit is present;(b) extracting one or more baseline pixel intensities from the at least one baseline photograph; and(c) calculating a ratio of the one or more pixel intensities from the at least one photograph taken of the IGU to the one or more baseline pixel intensities from the at least one baseline photograph.

[0078] Aspect 25. The method of any one of aspects 13-24, wherein the data from the at least one photograph represents spectral transmission of at least a portion of the electromagnetic spectrum through the IGU.

[0079] Aspect 26. The method of aspect 25, wherein the portion of the electromagnetic spectrum is between about 300 nm and about 2500 nm.

[0080] Aspect 27. The method of aspect 25 or 26, wherein the portion of the electromagnetic spectrum comprises ultraviolet light, visible light, infrared light, or any combination thereof..

[0081] Aspect 28. The method of any one of aspects 13-27, further comprising using a neutral density (ND) filter on the camera.

[0082] Aspect 29. The method of aspect 28, wherein the ND filter comprises an ND4 or an ND8 filter.

[0083] Aspect 30. A system for non-destructive evaluation of performance of single glazing units and insulated glazing units, the system comprising:(a) a full-spectrum digital camera comprising at least one lens;(b) an integrating sphere; and(c) a light source; wherein the full-spectrum digital camera is configured to capture an image of a collimated beam of light from the light source after light from the light source passes through the integrating sphere.

[0084] Aspect 31 . The system of aspect 30, wherein the integrating sphere further comprises an outlet pipe that focuses the collimated light exiting the integrating sphere on the camera lens.

[0085] Aspect 32. The system of aspect 31 , wherein the outlet pipe is painted matte black.

[0086] Aspect 33. The system of any one of aspects 30-32, wherein the integrating sphere is painted on an entire interior surface with high-reflective white paint.

[0087] Aspect 34. The system of any one of aspects 30-33, wherein the integrating sphere is painted on an entire exterior surface with black paint.

[0088] Aspect 35. The system of any one of aspects 30-34, wherein the light source comprises an LED emitting visible light, ultraviolet light, infrared light, ora combination thereof; a full-spectrum light source, the sun, or any combination thereof.

[0089] Aspect 36. The system of any one of aspects 30-35, further comprising a neutral density (ND) filter on the camera.

[0090] Aspect 37. The system of aspect 36, wherein the ND filter comprises an ND4 or an ND8 filter.EXAMPLES

[0091] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices and / or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the disclosure and are not intended to limit the scope of what the inventors regard as their disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric.Example 1: Custom Integrating Sphere

[0092] FIG. 2B shows an exemplary custom integrating sphere according to the present disclosure. The integrating sphere can be used to assess the properties of both single glazed windows and double glazed windows. The integrating sphere is constructed from foam with high-reflective paint on the inside and black paint on the outside to prevent light from entering other than where intended. The input slot and exit slot for the light source are positioned at a 900angle from one another. The light input can be a flash lamp or another light source. An outlet pipe is painted matte black to reduce and / or eliminate light reflection, ensuring uniform scattering and consistent light measurement.Example 2: Camera Calibration

[0093] In some experiments, neutral density (ND) filters can be used to reduce light intensity without altering the spectrum. Equipment can be calibrated using sequential ND filters (e.g., 100%, 50%, 25%, 12.5%, 0.1 %) in order to identify camera saturation threshold and calibrate response to varying light intensity. ND filters can be validated using UV-Vis and / or FTIR spectrometers. Peak transmittance and / or optical density can be measured across UV, visible, and NIR regions of the electromagnetic spectrum. In some experiments, ND filters are not used.Example 3: Extraction of Intensity Values from Digital Images

[0094] Images from a full spectrum camera are used in the disclosed methods. Although any full spectrum digital camera can be used in the disclosed methods, due to software andhardware differences among cameras, for each camera model, calibration will be required. Calibration of digital images is performed as follows for a Nikon D5300 camera; the method is essentially the same for other camera manufacturers and models.

[0095] In manual mode, the exposure is set to 1 / 125 s. Each image is taken at the same exposure setting. An image of the light source is taken through the integrating sphere and matte black constrained round pipe in the device as described above. Images are taken with and without glass samples in between the camera lens and the constrained pipe opening in order to provide for background correction. The process at this stage is the same for single glazing and double glazing samples.

[0096] The pixel intensities of the images are imported into a spreadsheet program such as Microsoft Excel or other data analysis program with similar capabilities. The images have a resolution of 6000 pixels by 4000 pixels, which equates to 6000 columns and 4000 rows in the spreadsheet.

[0097] To capture the intensity of the central core of the light source, the size of the image can be obtained from a software program capable of displaying images. In these experiments, Microsoft PowerPoint was used, but other photo display and / or editing software can also be used. In the present case, the images were 7.5 inches high and 11 .25 inches wide, meaning that each pixel covered 0.001875 inches. A sample image is shown in FIG. 5A.

[0098] A circle is drawn to cover the central core of the image, and a rectangle is drawn that touches the perimeter of the circle at each corner. The diagonals of the rectangle provide the coordinates for the center point of the circle.

[0099] A square of 1.15 inches by 1.15 inches is drawn, centering at the center point of the circle. The square is placed so its corners lie on the diagonals of the rectangle so that it captures the exact center of the light source image (FIG. 5B). The distances of this central square from the edges of the image are measured. The obtained distances are converted into pixels. Rows and columns are removed from the left, right, top, and bottom of the spreadsheet to leave a pixel intensity spreadsheet for only the central square of the image.

[0100] Background corrections can be supplied by subtracting pixel intensities for images without a glass sample between the camera lens and the constrained pipe opening. Pixel intensities can be converted to values such as thermal performance for single glazing units and filling gas (e.g. argon) concentration or thermal performance for double glazing units based on measurement of the same by a technique established in the art. Once the art- established technique is used to establish a set of values for filling gas concentration, thermal performance, or the like, it is not required to be performed again, and the disclosed methodscan be used exclusively.

[0101] Any part of the above calibration process can be automated by a script or computer program as desired.Example 4: Preliminary Results for Single Glazing Units

[0102] ND filters control the amount of light entering the camera lens, allowing for longer exposures without overexposure. A series of images were captured using ND filters from ND2 to ND1000, demonstrating a gradational diminution in brightness. FIG. 6A shows the linearity of ND filters, with a consistent and proportional decrease in light transmission as filter density increases. FIG. 6B shows spectral transmission properties through the same set of ND filters as in FIG. 6A. The ND4 and ND8 filters offer a balance between transmission and linearity across a broad range of wavelengths.

[0103] The LED light source used in these experiments exhibits a strong red component with a peak intensity at about 645 nm. FIG. 7 shows the percentage transmission across various wavelengths, showing robust output in the visible spectrum.

[0104] An experimental setup to evaluate the transmission properties of glass as used herein measures the properties by analyzing pixel values from images captured with a full-spectrum camera as described earlier. Table 1 compares the average pixel intensities with and without glass and calculates the percentage transmittance for different ND filters.

[0105] The ND8 filter was found to be particularly suitable for capturing light sources while maintaining spectral characteristics. In some experiments, analysis techniques have been refined so as not to require the ND filters.Example 5: Preliminary Results for Double Glazing Units

[0106] Images were captured with camera exposure set at 1 / 125 s. Pixel intensities were obtained as described previously. The transmittance values obtained match the theoretical visible transmittance. Results are presented in Table 2. It is noted that pixel intensities can vary with exposure time and calibration may need to be completed for each exposure time used.

[0107] These results show the light source used for experiments only supplies visible spectrum light rays. To verify the spectrum of the light rays coming from the light source used in these experiments, band pass filters were used. Images were taken without any glazing samples with 4 different configurations: The first image is of the light source directly into the camera lens (FIG. 8A), the second image used a visible light only band pass filter to capture an image (FIG. 8B), the third image used an IR-only filter (FIG. 8C), and the fourth image used a UV-only filter (FIG. 8D).

[0108] The intensity obtained in the case of no filter and the visible light filter was almost the same. A slight intensity was recorded with the IR-only filter, and no intensity was recorded with the UV-only filter (see Table 3).

[0109] Based on these preliminary experiments, it is believed a full spectrum light source and / or a light source mimicking the solar spectrum (i.e. wavelengths from about 300 nm to about 2500 nm) will provide more accurate results.

[0110] The presence of argon increased the pixel intensity compared to an otherwise identical glazing unit if at least one pane of glass was a low emissivity glass. In the case of clear-argon- clear glazing units, the presence of argon coincided with decreased average pixel intensity.

[0111] It should be emphasized that the above-described embodiments of the presentdisclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.REFERENCES1. Onatayo, D.A., et al. (2023). Ultraviolet Radiation Transmission in Building’s Fenestration: Part II, Exploring Digital Imaging, UV Photography, Image Processing, and Computer Vision Techniques Buildings 13(8), 1922.2. Onatayo, D. A., et al. (2023). Ultraviolet Radiation Transmission in Buildings’ Fenestration: Part I, Detection Methods and Approaches Using Spectrophotometer and Radiometer. Buildings, 13(7), 1670.

Claims

CLAIMSWhat is claimed is:

1. A method for assessing performance of a single glazing unit, the method comprising:(a) taking at least one photograph of the single glazing unit;(b) performing a baseline correction on the at least one photograph; and(c) correlating data from the at least one photograph to at least one performance-related property of the single glazing unit.

2. The method of claim 1 , wherein the at least one photograph is taken with a full-spectrum digital camera through an integrating sphere.

3. The method of claim 2, wherein full-spectrum light from a light source enters the integrating sphere and a collimated beam exits the integrating sphere.

4. The method of claim 1 , wherein the at least one performance-related property comprises a thermal property.

5. The method of claim 4, wherein the thermal property comprises R-value.

6. The method of claim 1 , wherein the data from the at least one photograph comprises one or more pixel intensities extracted from the at least one photograph, wherein the one or more pixel intensities are selected to eliminate pixels representing dispersed light.

7. The method of claim 6, wherein performing the baseline correction comprises:(a) taking at least one baseline photograph with the full-spectrum digital camera through the integrating sphere wherein no glazing unit is present;(b) extracting one or more baseline pixel intensities from the at least one baseline photograph; and(c) calculating a ratio of the one or more pixel intensities from the at least one photograph taken of the single glazing unit to the one or more baseline pixel intensities from the at least one baseline photograph.

8. The method of claim 1 , wherein the data from the at least one photograph represents transmittance of at least a portion of the electromagnetic spectrum through the single glazing unit.

9. The method of claim 8, wherein the portion of the electromagnetic spectrum is between about 300 nm and about 2500 nm.

10. The method of claim 8, wherein the portion of the electromagnetic spectrum comprises ultraviolet light, visible light, infrared light, or any combination thereof.

11. The method of claim 1 , further comprising using a neutral density (ND) filter on the camera.

12. The method of claim 11 , wherein the ND filter comprises an ND4 or an ND8 filter.

13. A method for assessing performance in an insulated glazing unit (IGU), the method comprising:(a) taking at least one photograph of the IGU;(b) performing a baseline correction on the at least one photograph; and(c) correlating data from the at least one photograph to at least one performance-related property of the IGU.

14. The method of claim 13, wherein the IGU is a double glazing unit.

15. The method of claim 13, wherein the IGU comprises one or more sheets of clear glass, one or more sheets of low emissivity glass, or any combination thereof.

16. The method of claim 13, wherein the IGU comprises a fill gas comprising air, argon, or any combination thereof.

17. The method of claim 16, wherein the fill gas comprises from about 96% to about 100% argon.

18. The method of claim 13, wherein the at least one photograph is taken with a full-spectrum digital camera through an integrating sphere.

19. The method of claim 18, wherein full-spectrum light from a light source enters the integrating sphere and a collimated beam exits the integrating sphere.

20. The method of claim 13, wherein the at least one performance-related property comprises a thermal property.

21. The method of claim 20, wherein the thermal property comprises R-value.

22. The method of claim 13, wherein the at least one performance-related property comprises argon percentage of fill gas.

23. The method of claim 13, comprises one or more pixel intensities extracted from the at least one photograph, wherein the one or more pixel intensities are selected to eliminate pixels representing dispersed light.

24. The method of claim 23, wherein performing the baseline correction comprises:(a) taking at least one baseline photograph with the full-spectrum digital camera through the integrating sphere wherein no glazing unit is present;(b) extracting one or more baseline pixel intensities from the at least one baseline photograph; and(c) calculating a ratio of the one or more pixel intensities from the at least one photograph taken of the IGU to the one or more baseline pixel intensities from the at least one baseline photograph.

25. The method of claim 13, wherein the data from the at least one photograph represents spectral transmission of at least a portion of the electromagnetic spectrum through the IGU.

26. The method of claim 25, wherein the portion of the electromagnetic spectrum is between about 300 nm and about 2500 nm.

27. The method of claim 25, wherein the portion of the electromagnetic spectrum comprises ultraviolet light, visible light, infrared light, or any combination thereof..

28. The method of claim 13, further comprising using a neutral density (ND) filter on the camera.

29. The method of claim 28, wherein the ND filter comprises an ND4 or an ND8 filter.

30. A system for non-destructive evaluation of performance of single glazing units and insulated glazing units, the system comprising:(a) a full-spectrum digital camera comprising at least one lens;(b) an integrating sphere; and(c) a light source; wherein the full-spectrum digital camera is configured to capture an image of a collimated beam of light from the light source after light from the light source passes through the integrating sphere.

31. The system of claim 30, wherein the integrating sphere further comprises an outlet pipe that focuses the collimated light exiting the integrating sphere on the camera lens.

32. The system of claim 31 , wherein the outlet pipe is painted matte black.

33. The system of claim 30, wherein the integrating sphere is painted on an entire interior surface with high-reflective white paint.

34. The system of claim 30, wherein the integrating sphere is painted on an entire exterior surface with black paint.

35. The system of claim 30, wherein the light source comprises an LED emitting visible light, ultraviolet light, infrared light, or a combination thereof; a full-spectrum light source, the sun, or any combination thereof.

36. The system of claim 30, further comprising a neutral density (ND) filter on the camera.

37. The system of claim 36, wherein the ND filter comprises an ND4 or an ND8 filter.

Images