Insulated glazing unit and a method of manufacturing

Abstract

The present invention relates to an insulated glazing unit, and a method of manufacturing an insulated glazing unit, wherein the insulated glazing unit comprises an angle-selective ray-rejection mesh at least partially within the cavity.

Description

[0001] Insulated Glazing Unit and a Method of Manufacturing

[0002] The present invention relates to an insulated glazing unit, and a method of manufacturing an insulated glazing unit.

[0003] Insulated glazing units may be installed to form part of a building envelope, such as windows or facades, and generally comprise at least two panes of glass separated by a spacer frame. Such insulated glazing units must balance the competing requirements of allowing the passage of sufficient natural visible light without excessive glare, provide a view out of the insulated glazing, and maintaining a comfortable internal temperature. When considering maintenance of a comfortable internal temperature, the prevention of unwanted solar heat gain is particularly important. Solar heat gain is caused when short-wave infra-red radiation of the sun's rays are transmitted through a glazing into an internal space. This short-wave infra-red radiation is absorbed by bodies such as furnishings and the internal fabric (walls, floors etc) within the space, which themselves become hot. The hot bodies lose energy to their environment by emission of long-wave infra-red radiation which is not transmitted by glass panes as effectively as short-wave radiation, and as such overall amount of heat in the space increases. The surfaces of the hot bodies also transfer energy to the air within the space by conduction, causing the air to rapidly increase to a temperature far in excess of the outside temperature.

[0004] While in some situations, such as during winter, solar heat gain is beneficial, solar heat gain is often undesirable. For example, solar heat gain in European summers can cause internal rooms to reach temperatures of over 40 °C even when the outside air temperature is less than 30 °C, creating an uncomfortable "oven like" atmosphere.

[0005] One way to manage unwanted solar heat gain in buildings is to use ventilation, whereby hot air is purged from the interior space and replaced with cooler air from the external environment. However, often even very high rates of air changes cannot cause a pleasant temperature to be established. Therefore, to maintain a comfortable building environment, many buildings are air- conditioned. However, air-conditioning is an extremely energy intensive process that is not attractive due to cost and the burden on the global environment. Therefore, it is desirable to prevent the transmission of short-wave radiation through glazings to prevent the solar gain from beginning. Conventional methods of reducing short-wave radiation transmission include shading, limiting the overall amount of glazing and orientating glazings away from the sun path. These conventional methods have considerable drawbacks. Shading, such as with a blind, often severely reduces the natural light transmission and prevents view through the glazing and is therefore undesirable. Similarly, limiting the overall amount of glazing and orientating glazings away from the sun path may limit natural light transmission and hinders viewing.

[0006] Further methods of reducing solar heat gain include the use of solar control coatings, which reflect infrared light. However, solar control coatings are not directional, and therefore do not prevent the transmission of infra-red radiation from "high angle" noon sun to a greater extent than "low angle" morning or evening sun. It is beneficial that "high angle" incident light is blocked to a greater extent than "low angle" incident light, as this allows the particularly intense rays of mid-day sun to be rejected while allowing the lower intensity rays of evening and morning sun to pass through, improving both view and daylighting quality while maintaining a high day long solar rejection potential.

[0007] Therefore, it is an aim of the invention to provide an insulated glazing that has improved directional infra-red radiation (IRR) rejection, reduced glare, and that may be manufactured in a cost-effective manner.

[0008] In a first aspect, the present invention provides an insulated glazing unit comprising: a first pane of glazing material comprising a first surface and a second surface; a second pane of glazing material comprising a third surface and a fourth surface, the second pane of glazing material being spaced apart from the first pane of glazing material such that the second surface is opposite the third surface; and a spacer frame between the first pane of glazing material and the second pane of glazing material, wherein the spacer frame is in direct or indirect contact with the second surface and the third surface such that a cavity is formed by the spacer frame, the first pane of glazing material and the second pane of glazing material, wherein the spacer frame delimits a cavity area in an orthographic projection through the first surface of the insulated glazing unit, wherein the insulated glazing further comprises an angle-selective ray-rejection mesh at least partially within the cavity. The inventors have found that the insulated glazing unit according to the present invention provides improved directional infra-red radiation rejection, leading to decreased solar heat gain, while maintaining a high degree of natural light transmission and visibility through the glazing. In addition, the insulated glazing provided by the invention does not have any reduction in the ability to clean the glazing caused by the addition of the angle-selective ray-rejection mesh. Furthermore, the angle-selective ray-rejection mesh is protected from damage and corrosion which may reduce its ability to prevent solar gain and / or will cause it to become aesthetically displeasing.

[0009] Preferably, the angle-selective ray-rejection mesh covers the entire cavity area. This arrangement causes the maximum solar rejection. However, in some cases a portion of the cavity area may be free of the angle-selective ray-rejection mesh, such as where high transmission is required, for example for sensors and cameras.

[0010] Preferably, the angle-selective ray-rejection mesh is under tension. This arrangement causes the angle-selective ray-rejection mesh to hold its position without encapsulation, which maximises solar rejection. Preferably, angle-selective ray-rejection mesh is not encapsulated within a laminated structure, such as a polyvinyl butyral film.

[0011] Preferably, the angle-selective ray-rejection mesh is captured, clamped and / or glued to the spacer frame. These methods of holding the angle-selective ray-rejection mesh may provide a secure, long-lasting connection that will last for the lifetime of the insulated glazing unit.

[0012] Preferably, the angle-selective ray-rejection mesh is not in direct contact with the first pane of glazing material or the second pane of glazing material. This arrangement prevents damage to the surfaces of the glazing panes, or damage to the angle-selective ray-rejection mesh during insulated glazing unit manufacture. Preferably, the angle-selective ray-rejection mesh is within the cavity, such that there are two cavity portions, one either side of the angle-selective rayrejection mesh, with each cavity portion comprising gas or vacuum.

[0013] The ray-rejection mesh comprises a sheet of louvres held by a wire warp, wherein the thickness of the sheet is from 0.5 mm to 10.0 mm, preferably from 1.0 mm to 5.0 mm, more preferably from 1.0 mm to 2.0 mm, yet more preferably from 1.0 mm to 1.6 mm. A thicker sheet thickness is associated with increased ray rejection, but is more easily seen and becomes difficult to handle, while a thinner sheet thickness is associated with improved visibility through the mesh, but has reduced ray rejection and is less durable.

[0014] A typical ray-rejection mesh is depicted by Figure 1. In figure 1 a ray rejection mesh 1 is depicted which comprises horizontal louvres 11 and vertical wires 12 forming a weft and warp type fabric construction. The wire warp is typically in a twisted arrangement (not shown) to securely hold the louvres 11 in place.

[0015] The louvres 11 are held by the wire warp 12 such that a wire 12 extends across a first axis of the mesh and a louvre 11 extends across a second axis of the mesh substantially perpendicular to the first. As such, when installed in a window or fagade, preferably the wires 12 of the wap extend vertically and the louvre 11 extend horizontally. The louvres 11 are substantially flat oblongs with a width Lw extending through the thickness of the mesh sheet, a length Ld associated with the width of the mesh sheet, a thickness Lt, and a distance between the louvres, pitch, Lp. The warp is made up of wires 12 and has a warp spacing Ws. The angle between the major surface of the louvres 11 and the axis formed by the wires 12 is the louvre angle La.

[0016] Preferably, the louvre width, Lw, is from 0.5 mm to 10.0 mm, preferably from 1.0 mm to 5.0 mm, more preferably from 1.0 mm to 2.0 mm, yet more preferably from 1.0 mm to 1.6 mm. The louvre width contributes to the main thickness of the sheet, and provides the ray-rejecting properties.

[0017] The louvre length Ld is defined by the overall width of the mesh, however in some embodiments the louvre length Ld may be shorter than the mesh width, where a louvre or louvres are cut.

[0018] The louvre thickness Lt is preferably from 0.10 to 1.00 mm, more preferably from 0.10 to 0.50 mm, more preferably from 0.20 to 0.40 mm. The louvre thickness has little influence on the rayrejecting properties, but a thicker louvre entails greater expense and decreased visibility through the mesh, while a thinner louvre is less durable.

[0019] The distance between the louvres, i.e. the louvre pitch Lp, is preferably from 0.5 mm to 10.0 mm, preferably from 1.0 mm to 5.0 mm, more preferably from 1.0 mm to 2.0 mm, yet more preferably from 1.0 mm to 1.6 mm. The pitch Lp cooperates with the louvre width Lw to provide the ray- rejecting properties. An increased pitch allows more light to pass through, while a decreased pitch decreases the light transmission. The louvre pitch is measured centre to centre.

[0020] The warp spacing Ws is preferably from 5.0 to 20.0 mm, more preferably from 10.0 to 15.0 mm, more preferably from 12.0 to 13.0 mm. An increased warp spacing decreases cost but decreases durability, while an decreased warp spacing increases durability but decreases cost.

[0021] The louvre angle between the major surface of the louvres and the axis formed by the wires La is preferably from 0° to 45°, more preferably from 0° to 30°. In some embodiments, the louvre angle La is from 10° to 25°, more preferably from 15° to 20° - this may be beneficial where the mesh is designed to be used in a vertical arrangement. In alternative embodiments, preferably the louvre angle is around 0° - this may be beneficial where the mesh is designed to be in an inclined arrangement, such as in a rooflight.

[0022] In a preferred arrangement, the angle-selective ray-rejection mesh has the following combined properties:

[0023] These combinations of parameters provide an angle-selective ray-rejection mesh that, when combined with the insulated glazing unit as in the present invention and installed vertically in a building envelope, greatly reduces solar heat transmission while maintaining other beneficial properties such as visible light transmission.

[0024] The angle-selective ray-rejection mesh preferably comprises metal, preferably bronze. Metals are preferred for their high durability and reflectivity, and bronze is particularly preferred. Preferably, the angle-selective ray-rejection mesh comprises from 50 to 95% C230 bronze and from 5 to 50% C655 silicon bronze, preferably from 70 to 95% C230 bronze and from 5 to 30% C655 silicon bronze, more preferably from 85 to 95% C230 bronze and from 5 to 15% C655 silicon bronze.

[0025] C230 bronze comprises CussZnis, and C655 silicon bronze comprises CugeMnSis.

[0026] In some embodiments the angle-selective ray-rejection mesh may be coated, for example by powder coating, for altered aesthetic appearance. However, it is preferred that the mesh is not coated, as this increases absorption of energy by the mesh, rather than reflection. Energy absorbed by the mesh is re-radiated, causing increases heat transmission through the glazing.

[0027] In a second aspect, the present invention provides a method of manufacturing an insulated glazing unit comprising the steps of: i) providing a spacer frame suitable for an insulated glazing unit; ii) securing an angle-selective ray-rejection mesh to the spacer frame; iii) providing a first pane of glazing material comprising a first surface and a second surface and a second pane of glazing material comprising a third surface and a fourth surface; and iv) arranging spacer frame between the first pane of glazing material and the second pane of glazing material, wherein: the spacer frame is in direct or indirect contact with the second surface and the third surface such that a cavity is formed by the spacer frame, the first pane of glazing material and the second pane of glazing material; the second pane of glazing material is spaced apart from the first pane of glazing material such that the second surface is opposite the third surface; the angle-selective ray-rejection mesh is at least partially within the cavity; and the spacer frame delimits a cavity area in an orthographic projection through the first surface of the insulated glazing unit.

[0028] Preferably the insulated glazing so manufactured is according to the first aspect of the present invention.

[0029] Preferably the method further comprises a step of stretching the angle-selective ray-rejection mesh across the spacer frame. Preferably, the angle-selective ray-rejection mesh is at least partially secured to the spacer frame prior to the stretching step. Alternatively, the angle-selective ray-rejection mesh is secured to the spacer frame following the stretching step. Aspects of the first aspect may be applied to the second aspect in any combination, and vice versa.

[0030] According to a third aspect of the present invention there is provided an architectural glazing comprising an insulated glazing according to the first aspect of the invention or manufactured according to the second aspect of the present invention.

[0031] The skilled person will appreciate that optional or preferable features of aspects of the present invention may be applied to other aspects according to their needs and requirements.

[0032] The present invention will now be described by way of example only, and with reference to, the accompanying drawings, in which:

[0033] Figure 1 illustrates schematically an angle-selective ray-rejection mesh;

[0034] Figure 2 illustrates schematically an insulated glazing unit according to the first aspect of the present invention;

[0035] Figure 3 illustrates schematically the insulated glazing unit of Figure 2 viewed through the glazing.

[0036] Figures 2 and 3 illustrate an insulated glazing unit 100 comprising a first pane of glazing material 110 comprising a first surface 111 and a second surface 112 and a second pane of glazing material 120 comprising a third surface 123 and a fourth surface 124. The second pane of glazing material 120 is spaced apart from the first pane of glazing material 110 such that the second surface 112 is opposite the third surface 123. The insulated glazing comprises a spacer frame 130 between the first pane of glazing material 110 and the second pane of glazing material 120, wherein the spacer frame 130 is in direct or indirect contact with the second surface 112 and the third surface 123 such that a cavity 140 is formed by the spacer frame 130, the first pane of glazing material 110 and the second pane of glazing material 120, the spacer frame 130 delimiting a cavity area 150 in an orthographic projection through the first surface 111 of the insulated glazing unit 100, wherein the insulated glazing 100 further comprises an angle-selective ray-rejection mesh 160 at least partially within the cavity 140. In this embodiment the angle-selective ray-rejection mesh 160 covers the entire cavity area 150.

[0037] The inventors have found that arrangements according to the present invention are particularly beneficial for producing a durable, long lived insulated glazing which is able to allow a high amount of visible light while preventing high energy solar heat gain caused by infra-red radiation originating from the sun.

Claims

Claims1. An insulated glazing unit comprising: a first pane of glazing material comprising a first surface and a second surface; a second pane of glazing material comprising a third surface and a fourth surface, the second pane of glazing material being spaced apart from the first pane of glazing material such that the second surface is opposite the third surface; and a spacer frame between the first pane of glazing material and the second pane of glazing material, wherein the spacer frame is in direct or indirect contact with the second surface and the third surface such that a cavity is formed by the spacer frame, the first pane of glazing material and the second pane of glazing material, wherein the spacer frame delimits a cavity area in an orthographic projection through the first surface of the insulated glazing unit, wherein the insulated glazing further comprises an angle-selective ray-rejection mesh at least partially within the cavity.

2. An insulated glazing according to claim 1, wherein the angle-selective ray-rejection mesh covers the entire cavity area.

3. An insulated glazing according to claim 1 or claim 2, wherein the angle-selective rayrejection mesh is under tension.

4. An insulated glazing according to any preceding claim, wherein the angle-selective rayrejection mesh is captured, clamped and / or glued to the spacer frame.

5. An insulated glazing according to any preceding claim, wherein the angle-selective rayrejection mesh is not in direct contact with the first pane of glazing material or the second pane of glazing material.

6. An insulated glazing according to any preceding claim, wherein the angle-selective rayrejection mesh has a sheet thickness from 0.5 mm to 10.0 mm, preferably from 1.0 mm to 5.0 mm, more preferably from 1.0 mm to 2.0 mm, yet more preferably from 1.0 mm to 1.6 mm.

7. An insulated glazing according to any preceding claim, wherein the angle-selective rayrejection mesh comprises a sheet of louvres held by a wire warp.

8. An insulated glazing according to claim 7, wherein the angle-selective ray-rejection mesh has a louvre width, Lw, from 0.5 mm to 10.0 mm, preferably from 1.0 mm to 5.0 mm, more preferably from 1.0 mm to 2.0 mm, yet more preferably from 1.0 mm to 1.6 mm.

9. An insulated glazing according to claim 7 or claim 8, wherein the angle-selective rayrejection mesh has a louvre thickness, Lt, from 0.10 to 1.00 mm, more preferably from 0.10 to 0.50 mm, more preferably from 0.20 to 0.40 mm.

10. An insulated glazing according to any of claims 7 to 9, wherein the angle-selective rayrejection mesh has a louvre pitch, Lp, from 0.5 mm to 10.0 mm, preferably from 1.0 mm to 5.0 mm, more preferably from 1.0 mm to 2.0 mm, yet more preferably from 1.0 mm to 1.6 mm.

11. An insulated glazing according to any of claims 7 to 10, wherein the angle-selective rayrejection mesh has a louvre angle, La, from 0° to 45°, more preferably from 0° to 30°.

12. An insulated glazing according to any preceding claim, wherein the angle-selective rayrejection mesh comprises metal, preferably bronze13. An insulated glazing according to claim 12, wherein the angle-selective ray-rejection mesh comprises from 50 to 95% C230 bronze and from 5 to 50% C655 silicon bronze, preferably the angle-selective ray-rejection mesh comprises from 70 to 95% C230 bronze and from 5 to 30% C655 silicon bronze, more preferably the angle-selective ray-rejection mesh comprises from 85 to 95% C230 bronze and from 5 to 15% C655 silicon bronze.

14. A method of manufacturing an insulated glazing unit comprising the steps of: i) providing a spacer frame suitable for an insulated glazing unit; ii) securing an angle-selective ray-rejection mesh to the spacer frame; iii) providing a first pane of glazing material comprising a first surface and a second surface and a second pane of glazing material comprising a third surface and a fourth surface; and iv) arranging the spacer frame between the first pane of glazing material and the second pane of glazing material, wherein:the spacer frame is in direct or indirect contact with the second surface and the third surface such that a cavity is formed by the spacer frame, the first pane of glazing material and the second pane of glazing material; the second pane of glazing material is spaced apart from the first pane of glazing material such that the second surface is opposite the third surface; the angle-selective ray-rejection mesh is at least partially within the cavity; and the spacer frame delimits a cavity area in an orthographic projection through the first surface of the insulated glazing unit, preferably wherein the insulated glazing so manufactured is according to any of claims 1 to 13.

15. A method according to claim 14, further comprising a step of stretching the angle-selective ray-rejection mesh across the spacer frame.

16. A method according to claim 15, wherein the angle-selective ray-rejection mesh is at least partially secured to the spacer frame prior to the stretching step.

17. A method according to claim 15, wherein the angle-selective ray-rejection mesh is secured to the spacer frame following the stretching step.

18. An architectural glazing comprising an insulated glazing according to any of claims 1 to 13, or manufactured according to any of claims 14 to 17.

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