WO2020099863A1

WO2020099863A1 - Glazing unit

Info

Publication number: WO2020099863A1
Application number: PCT/GB2019/053210
Authority: WO
Inventors: George TSIANTAR
Original assignee: Tsiantar Architects Limited
Priority date: 2018-11-13
Filing date: 2019-11-13
Publication date: 2020-05-22
Also published as: GB201818479D0; GB2578904B; GB2578904A

Abstract

A glazing unit comprises two panes of glazing material separated by at least one spacer and defining an interior volume. Said at least one spacer has a body comprising a first opening, a second opening, and a filter arrangement. The at least one spacer is disposed such that the first opening adjoins the interior volume, the second opening adjoins an exterior volume of air which is exterior to the interior volume, and the first and second openings are in fluid communication via the filter arrangement.

Description

Glazing Unit

Field of the Invention

The present invention relates to a breathable spacer for use in glazing units and processes for their manufacture, as well as glazing units comprising one or more said breathable spacers and processes for their manufacture.

Background

As is well known, the purpose of windows is to provide natural light to the interior of buildings and allow vision between the building interior and exterior, while providing a physical barrier to the ingress of adverse weather (e.g. rain) and ambient air. The exclusion of ambient air facilitates the maintenance of an environment (air temperature, humidity etc.) within buildings that are different to that of the ambient environment (principally to maintain warmer building temperatures in cold environments, but also to maintain cooler building temperatures in hot environments).

In order to facilitate the above purposes, windows are generally made of transparent materials, typically glass, which have poor insulating properties and readily allow the thermal conduction of heat, equilibrating the temperature of air within the building and that of the ambient air outside the building. In order to improve the energy efficiency of buildings (thereby reducing running energy costs) it has become standard to use double-glazing, wherein two panes of glass are provided spaced apart in a sealed unit, the resulting air gap between the panes of glass provides additional insulation while allowing light to pass through unimpeded. As the units are sealed, the air within the air gap is often replaced with Argon or Krypton to further improve the insulating properties of the double-glazing unit.

The presence of water-vapour within the air gap leads to condensation of the water and misting of the glass, impeding the ingress of light and obscuring vision through the unit. It is therefore common practice that double-glazing units are sealed to prevent water (vapour or liquid) entering the unit. Additionally, sealing the unit prevents the ingress of contaminants such as dust, insects and potentially damaging chemicals which may lead to obscuring of the glass (e.g. by physically blocking light or damaging the surface of the glass or its coatings). As the units are sealed, the mass of gas within the air gap is constant. As the temperature of the gas within the air gap changes, so too does its pressure, this leads to the glass of the unit bowing outwards when warm (relatively high pressure gas), and bowing inwards when cold (relatively low pressure gas). Bowing inwards is particularly problematic as it leads to a reduction in the width of the air gap during cold weather, thereby reducing the insulation efficiency of the double-glazing unit when it is most needed. The bowing can also distort the view through the window due to the convexity, or concavity, of the glass. In extreme cases, the glass panes can be cracked by the bowing.

The repeated bowing of the glass may eventually leads to failure of sealing of the sealed unit. With the sealing broken, water vapour is free to enter, increasing in concentration within the unit and causing misting of the glass when it condenses. This is especially noticeable should the sealing for the internal-facing pane, positioned between building air and the air gap, fail as air within buildings has a higher moisture content than outside air.

Misting, ultimately caused by sealing failure, is the primary reason for the failure of double glazing units and necessitates their repair or replacement.

In light of the above, the lifespan of double-glazing units is 10 to 20 years, after which they will require costly repair or replacement. Part of this high cost is due to the complexity of conventional, sealed double glazing units and their manufacture. This is a significant problem as double glazing typically takes 40 to 60 years to repay the cost of installation through reduced energy costs, thereby undermining one of the main reasons for their installation.

Furthermore, the magnitude of the pressure difference between the gas within the air gap and ambient air, and therefore the magnitude of the bowing caused by the force applied to the glass, is proportional to the volume of air in the air gap. This therefore places a size constraint on the dimensions of the double-glazing unit, which is primarily dependent on the width of the air gap, which is typically limited to a maximum of between 12 and 20 mm. This sets a limit to the insulating efficiency of the double glazing unit as its rate of thermal conduction is inversely proportional to the width of its air gap. It is the object of the present invention to address at least one of the problems with known glazing units, whether discussed above or otherwise.

Summary of the Invention

The present invention relates to a vented double glazing unit with improved insulating properties and lifespan. The present invention also relates to a spacer, which may be used for vented double glazing units according to the present invention. The present invention also relates to method for the production of vented double glazing units according to the present invention and to methods for the production of a spacer. The present invention further relates to the use of a spacer for retrofitting to and/or the repair of existing double glazing units.

A first aspect of the present invention relates to a glazing unit comprising two panes of glazing material separated by at least one spacer and defining an interior volume, wherein said at least one spacer comprises a body having a first opening, a second opening, and a filter arrangement, the at least one spacer disposed such that:

the first opening adjoins the interior volume of air,

the second opening adjoins an exterior volume of air which is exterior to the interior volume, and

the first and second openings are in fluid communication via the filter arrangement.

The filter arrangement permits the movement of gases (e.g. air and/or water vapour) between the first and second openings, and therefore also permits the movement of such gases between the interior and exterior volumes, while preventing the movement of debris, insects, dust and other particulates. This arrangement allows for water vapour to freely move out of the glazing unit. This arrangement also allows for the pressure within the interior volume (e.g. the air gap) to equilibrate with the pressure within the exterior volume (e.g. outside air), thereby preventing bowing of the glazing material and improving the lifespan and insulating properties of the glazing unit. A further advantage lies in that the fluid communication through the filter arrangement, although sufficient to prevent bowing and misting, is sufficiently limited to prevent the movement of large volumes of air. This provides the unexpected advantage in that it allows the glazing unit to be vented without having a detrimental effect on its thermal performance. In other words, although vented to outside air, the temperature of the interior volume does not equilibrate with the outside air (and hence the temperature of the outside air does not equilibrate with air on the other side of the glazing unit (i.e. inside) to that in contact with the outside air).

At least portion of the filter arrangement may be disposed within the body.

The body may be hollow. The hollow body may define at least a portion of the filter arrangement and a filter material of the filter arrangement may be located within the hollow body.

The hollow body may define a filter chamber of the filter arrangement in fluid communication with the first and second openings, and the filter chamber may contain filter material. The filter chamber may be filled with filter material.

The filter arrangement may comprise a filter material. The filter material may be a carbon filter material. The carbon filter material may be a compressed carbon impregnated microfibrous foam filter material. Such filter materials are easily handled and assembled into the spacer, allow free movement of water vapour (thereby relieving misting by preventing the build-up of moisture within the interior volume of air) and prevent the ingress of even small dust particulates. In addition, such materials are also able to adsorb organic compounds (such as volatile organic solvents - VOCs) which may damage coatings on the interior surface of the glass, reducing their clarity.

The first and/or second opening may comprise a plurality of openings. Put another way, the first opening may be one of a plurality of first openings and/or the second opening may be one of a plurality of second openings.

The skilled person will understand that the size (e.g. cross-sectional area) and number of first and second openings may define the rate of air that may move through the spacer and is therefore desirably chosen to permit sufficient air flow such that water vapour does not build up within the interior volume, thereby preventing misting. The permitted air flow may also be sufficient to enable pressure equilibration between the interior and exterior volumes. The permitted air flow may be limited to prevent thermal equilibration between the interior and exterior volumes. The first opening(s) and second opening(s) may be on opposite sides of the body.

Opposite sides is not intended to mean that the first opening and second opening, or the pluralities thereof, must be in direct opposition to one another, although they may be. Opposite sides is also not intended to mean that the first and second openings are coaxial, for example, with a longitudinal axis of the body, although they may be.

Under one interpretation, opposite sides is intended to mean that it is possible to divide a cross-section of the body into two continuous, generally equally sized sections, one of which contains only the first opening or plurality of openings and the other of which contains only the second opening or plurality of openings. In this arrangement, it is ensured that when the spacer is positioned between the panes of glazing material, the first opening, or plurality of openings, adjoins the interior volume; and the second opening, or plurality of openings, adjoins the exterior volume.

In a particular embodiment, a plurality of first openings and/or a plurality of second openings are arranged in a single line parallel to an elongate axis of the body / spacer. In alternative embodiments, a plurality of first openings and/or a plurality of second openings are arranged into two or more lines parallel to the length of the spacer.

The first opening(s) and second opening(s) may be located on perpendicular sides of the body. It will be understood by the skilled person that the second opening(s) are still required to adjoin the exterior volume of air and, as such, may not be located on sides of the body intended to contact the panes of glazing material and/or airtight elements, if used. The second opening may comprise an open face of the body (e.g. the body may comprise a tube, a pipe or similar with one or two open ends, said one or two open ends constituting one or two second openings respectively). The second opening(s) may be located on a face of the body which is generally perpendicular to the elongate axis of the body / spacer.

In a particular embodiment, the first opening(s) may be located on a single side of the body and the second opening(s) may be located on both a side of the body opposite to said single side, and a side of the body which is perpendicular to said single side.

The body may comprise aluminium. Alternatively, the body may comprise plastic. The spacer may be elongate and have a rectangular cross-section, the rectangular cross-section may have chamfered or rounded edges. Cross-section being defined herein as the plane perpendicular to the axis running in the direction in which the spacer is elongate (i.e. the longitudinal axis of the spacer).

The spacer may further comprise an airtight element affixed to the body. By airtight, what is meant is that element substantially prevents fluid flow (e.g. airflow) through it between the interior volume and the exterior volume. The airtight element may comprise aluminium or foam. The inclusion of a simpler, more cost effective airtight element reduces the cost per unit length of the spacer. In addition, if the airtight element comprises a material with greater insulating properties than the body, the insulating efficiency of the spacer is improved by reducing the thermal conductivity across the width of the spacer. This reduces the spacer’s capacity to form cold bridges when it is included in a glazing unit. The airtight element may be used to increase the total thickness of the spacer so that that spacer supports the first and second panes of glazing material at a desired separation. By using a variety of thicknesses of airtight element it is possible to use the same spacer body to form spacers with a variety of different total thicknesses (which can thereby support a variety of desired spacings between the first and second panes of glazing material).

The airtight element may be affixed to the body by an adhesive.

The airtight element may be the same length and/or height as the body. This enables the spacer to have a constant cross-section, so that when positioned between panes of glazing material there are no significant pathways that air may flow through without passing through the filter material.

The panes of glazing material may be generally parallel to one another and the separation between the panes of glazing material may be at least one of: in the range of about 10 mm to about 60 mm, in the range of about 20 mm to about 50 mm, and in the range of about 30 mm to about 40 mm. Unlike conventional glazing units, in glazing units according to the present invention, the separation between the panes of glazing material is not restricted by the possibility of pressure differentials developing between the interior volume and the exterior volume. This allows for greater separation between the panes of glazing material, thereby improving thermal efficiency of the glazing units. The spacer may define the separation between the panes of glazing material. Opposing faces of the spacer may be affixed to the glazing material.

The opposing faces of the spacer may be affixed to the glazing material using adhesives (such as glue, double sided glazing tape or butyl bead).

The glazing unit may further comprise a frame housing the edges of the panes of glazing material, the frame having an internal face and an external face. The internal face is the face which, when the glazing unit has been installed, is in contact with air inside the building in which the glazing unit is installed. The external face is the face which, when the glazing unit has been installed, be in contact with air outside the building in which the glazing unit is to be installed. The skilled person will understand that glazing units typically include a frame around the edge of the glass for reasons of support, safety and aesthetics.

The exterior volume may be divided into a frame volume defined by the panes of glazing material, the spacer and the frame, and a free volume, also wherein the frame comprises a third opening in fluid communication with the second opening via the frame volume.

The third opening may be located in the external face of the frame. This allows the interior volume to be in fluid communication (via the first, second and third openings) with outside air, which generally possesses a lower moisture content than air found within buildings.

The third opening may comprise a plurality of openings. Put another way the third opening may be one of a plurality of third openings.

A filter cap may be located at the third opening(s). The cap may comprise a coarse filter. The cap may prevent the ingress of large dust particles, debris and insects into the frame of the glazing unit while allowing the free movement of gases.

The frame may be comprised of aluminium, PVC and/or timber. The spacer may further comprise a back plate affixed to the spacer of the present invention, the width of which is greater than that of the spacer such that it extends over the edges of the panes of glazing material when the spacer is disposed between them. Alternatively, the back plate may be integral to the spacer (i.e. formed as a single piece). The back plate may also be used in conjunction with non-breathable spacers known in the art. The back plate may include perforations, voids or vents to ensure that the fluid communication between the interior and exterior volumes is not disrupted by the back plate. When the spacer comprising a back plate is disposed between panes of glazing material, the edges of the panes may be affixed to the edges of the glazing material. The affixing may be achieved by use of adhesives (such as glue, double sided glazing tape or butyl bead). The back plate advantageously protects the edges of the panes of glazing material, ensures that the spacer is accurately located relative to the panes of glazing material and, when affixed to the edges of the panes of glazing material, enhances the rigidity of the glazing unit as a whole.

A second aspect of the present invention relates to a spacer for a glazing unit having a body comprising:

a first opening,

a second opening, and

a filter arrangement, wherein the first and second opening are in fluid communication via the filter arrangement.

At least a portion of the filter arrangement may be disposed within the body.

The filter arrangement may comprise a filter material. The filter material may be a carbon filter material. The carbon filter material may be a compressed carbon impregnated microfibrous foam filter material. Such filter materials are easily handled and assembled into the spacer, allow free movement of water vapour and prevent the transmission of even small dust particulates. In addition, such materials are also able to adsorb organic compounds (such as volatile organic solvents - VOCs).

The skilled person will understand that the size (e.g. cross-sectional area) and number of first and second openings may define the rate of air that may move through the spacer.

The first opening(s) and second opening(s) may be on opposite sides of the body. Opposite sides is not intended to mean that the first opening and second opening, or the pluralities thereof, must be in direct opposition to one another, although they may be. Opposite sides is also not intended to mean that the first and second openings are coaxial, for example, with a longitudinal axis of the body, although they may be.

Under one interpretation, opposite sides is intended to mean that it is possible to divide the cross-section of the body into two continuous, generally equally sized sections, one of which contains only the first opening or plurality of first openings and the other of which contains only the second opening or plurality of second openings. In this arrangement, it is ensured that when the spacer is positioned between the panes of glazing material, the first opening, or plurality of openings, adjoins the interior volume the second opening, or plurality of openings, adjoins the exterior volume.

In a particular embodiment, a plurality of first openings and/or a plurality of second openings are arranged in a single line parallel to the elongate axis of the spacer. In alternative embodiments, a plurality of first openings and/or a plurality of second openings are arranged into two or more lines parallel to the length of the spacer.

The first opening(s) and second opening(s) may be located on perpendicular sides of the body. It will be understood by the skilled person that the second opening(s) are still required to adjoin the exterior volume of air and, as such, may not be located on sides of the body intended to contact the panes of glazing material and/or airtight elements, if used. The second opening may comprise an open face of the body (e.g. the body may comprise a tube, a pipe or similar with one or two open ends constituting one or two second openings respectively). The second opening(s) may be located on a face of the body which is generally perpendicular to the elongate axis of the body / spacer.

In a particular embodiment, the first openings may be located on a single side of the body and the second openings may be located on both the opposite and perpendicular sides of the body.

The body may comprise aluminium. Alternatively, the body may comprise plastic.

The spacer may be elongate and have a rectangular cross-section, the rectangular cross-section may have chamfered or rounded edges. Cross-section being defined herein as the plane perpendicular to the axis running in the direction in which the spacer is elongate (i.e. the longitudinal axis of the spacer).

The spacer may further comprise an airtight element affixed to the body. By airtight, what is meant is that element substantially prevents fluid flow (e.g. airflow) through it between the interior volume and the exterior volume. The airtight element may comprise aluminium or foam. The inclusion of a simpler, more cost effective airtight element reduces the cost per unit length of the spacer. In addition, if the airtight element comprises a material with greater insulating properties than the body, the insulating efficiency of the spacer is improved by reducing the thermal conductivity across the width of the spacer. This reduces the spacer’s capacity to form cold bridges. The airtight element may be used to increase the total thickness of the spacer so that that spacer supports the first and second panes of glazing material at a desired separation. By using a variety of thicknesses of airtight element it is possible to use the same spacer body to form spacers with a variety of different total thicknesses (which can thereby support a variety of desired spacings between the first and second panes of glazing material). The airtight element may be affixed to the body by an adhesive.

The cross-sectional width of the spacer may be at least one of: in the range of about 10 mm to about 60 mm, in the range of about 20 mm to about 50 mm, and in the range of about 30 mm to about 40 mm. Cross-sectional width being defined herein as the measurement perpendicular to the faces of the spacer which are to be in contact with the glazing material when the spacer is part of a glazing unit. Cross-sectional width may also be defined as width in a direction perpendicular to the planes of the glazing material, when the spacer is in use.

A third aspect of the present invention relates to a method for fabricating a glazing unit, the method comprising the steps of:

positioning at least one spacer according to the second aspect of the present invention between two panes of glazing material, wherein the spacer and panes of glazing material define an interior volume, and wherein the first opening adjoins the interior volume, and the second opening adjoins an exterior volume which is exterior to the interior volume.

The method may further comprise affixing the spacer to each of the panes of glazing material. The spacer may be affixed to each of the panes of glazing material with an adhesive.

Brief Description of Figures

Figure 1 is a cross section of an embodiment of a glazing unit comprising a spacer bar in accordance with the present invention;

Figure 2 is a cross section of a second embodiment of a glazing unit comprising a spacer bar in accordance with the present invention; Figure 3 is a cross section of a third embodiment of a glazing unit comprising a spacer bar in accordance with the present invention;

Figures 4a and 4b are schematic perspective and cross-sectional views of a first embodiment of spacer bar;

Figures 5a and 5b are schematic perspective and cross-sectional views of a second embodiment of spacer;

Figures 6a and 6b are schematic perspective and cross-sectional views of a third embodiment of spacer bar; and

Figures 7a and 7b are schematic perspective and cross-sectional views of a fourth embodiment of spacer.

Within the Figures equivalent features are numbered with the same reference numeral.

Detailed Description of the Invention

In one embodiment, illustrated in Figure 1 , the glazing unit 10 of the present invention is a component in a fixed window. The panes of glazing material 12 are formed of glass and are held at a separation S of 34 mm. The separation is maintained by a breathable spacer 14 of the present invention located at the bottom of the panes and conventional (i.e. non-breathable) spacers 16 located at the top and sides of the panes. Both types of spacers are elongate have a uniform cross-section corresponding to a rectangle with chamfered corners, are of the same height H (15 mm) and are affixed to the glass using butyl bead 18. The conventional spacers 16 are formed of foam and are impermeable (and, in particular, substantially impenetrable to air). The breathable spacer 14 is comprised of a hollow body 22 formed of aluminium which is perforated both top (22a) and bottom (22b). The hollow body 22 is filled with a carbon filter material 24, which forms part of a filter arrangement.

The panes of glass 12, the conventional spacers 16 and the breathable spacer 14 surround and define an interior volume 25. N.B. the‘gaps’ indicated by dashed lines and the reference letter F within the figure are not present in reality, they are merely separations in the figure to enable both the upper portion and lower portion of the glazing unit to be shown in the same figure.

The panes of glass 12 are held in a frame 26 formed of aluminium. The frame is of conventional design for a fixed aluminium-framed window, with the addition of 5 mm openings 28 (only one of which is shown in the Figure) formed in the exterior face with 300 mm spacing between their centres. Filter caps 30 formed of powder-coated stainless steel are set into the openings 28.

The frame defines a frame volume 32 and the volume not contained with the frame volume 32 or the interior volume 25 is referred to as the free volume 34. The free volume 34 may be referred to as atmosphere. The interior volume 25 is in fluid communication with the frame volume 32 via the carbon filter 24. The frame volume 32 is in fluid communication with the free volume 34 via filter caps 30. As such, all three volumes are in fluid communication with one another, allowing the free movement of water vapour out of the interior volume 25 and preventing the creation of pressure differentials between the interior volume 25 and free volume 34.

In another embodiment, illustrated in Figure 2, the glazing unit 50 is a component in an openable window.

The panes of glazing material 12 are formed of glass and have a separation S of 34 mm. The separation is maintained by a combination of breathable spacers 14 and non- breathable spacers 16, as described in relation to Figure 1.

The panes of glass 12 are held in a frame formed of PVCu. The frame is of conventional design for an openable PVCu-framed window suitable for triple glazing, with the addition of 5 mm openings 28 (only one of which is visible at the base of each pair of panes of glazing material in the Figure) in the exterior face, the centres of which are spaced by 300 mm. Filter caps 30 formed of powder coated stainless steel are set into the openings.

An interior volume 25, frame volume 32 and free volume 34 (e.g. atmosphere) are defined, and are in fluid communication, as described in the embodiment illustrated in Figure 1. In a further embodiment, illustrated in Figure 3, the glazing unit 70 is a component in a further type of openable window.

The panes of glazing material 12 are formed of glass and have a separation S of 34 mm. The separation is maintained by a combination of breathable spacers 14 and non- breathable spacers (not shown), as described in relation to Figure 1.

In this embodiment, panes of glass 12 are held in a frame 72 formed of timber. The frame is of conventional design for an openable timber-framed window, with the addition of a PVC vent holes (only one of which is visible in the figure) fitted into the frame at 300 mm intervals. The vent hole 74 is fitted with a mesh 76 to prevent the ingress of dust and insects.

In this arrangement the opening (PVC vent holes 74) connecting the frame volume 32 with the free volume 34 (e.g. atmosphere) is hidden from view (in reality, although visible in the Figure) and the fluid communication is via a gap 32a between the bottom of the frame 72 and the top of the cill 78. This is particularly suitable for wooden frames as these tend to be painted to protect the wood or for aesthetic reasons. Application of paint to the filter cap or mesh would seal the opening, preventing the free movement of gases between the frame and free volumes. By concealing the vent hole and recessing the mesh, the risk of inadvertently applying paint to these features can be reduced. To further reduce these risks, filter caps may be used which project out from the surface, to make their location obvious on inspection, and may be marked with“No Paint” or equivalent phrases.

Note that in this embodiment, the breathable spacer 14 is located at the top edge of the panes of glass 12. The interior volume 25 is still in fluid communication with the free volume 34 (e.g. atmosphere) as the intermediate frame volume 32 runs around the entire perimeter of the panes of glass within the frame, thereby ensuring fluid connection between the top perforation 22a and the opening 28 at the base of the unit.

Figures 4 and 5 show schematic perspective (Figures 4a and 5a) and cross-sectional (Figures 4b and 5b) views of a two embodiments of spacer bar (14, 14a) according to the present invention. The cross-sectional views are taken along the longitudinal axis L in the orientation and direction indicated by C.

Both spacer bars (14, 14a) do not, in this instance, include an airtight element. However, in other embodiments the spacer bars may include airtight elements.

Both spacer bars 14, 14a include a hollow body 22, 22c, which is filled with filter material 24.

The first spacer bar 14 shown in Figure 4 includes a row of first openings 22a and a row of second openings 22b, which extend along the longitudinal axis L of the spacer bar 14 and which are spaced R by about 30mm. Of course, in other embodiments there may be any number of first openings and any number of second openings and they may be spaced by any appropriate amount.

In the spacer bar 14 shown in Figure 4, the first openings 22a and second openings 22b are on opposite sides of the body 22. That is to say, the first openings 22a are located on a first side 22e of the body 22, and the second openings 22b are located on a second side 22f of the body 22, the first and second sides 22e, 22f being opposite sides of the body 22.

In this arrangement, it is ensured that when the spacer 22 is positioned between panes of glazing material, the first openings 22a adjoin the interior volume; and the second openings adjoin the exterior volume.

The first openings 22a and second openings 22b are each arranged in a single line parallel to the elongate axis L of the body 22.

The second spacer bar 14a shown in Figure 5 includes a row of first openings 22a located on a first side 22e of the body 22, which extend along the longitudinal axis L of the spacer bar 14a and which are spaced R by about 30mm. In addition, the spacer bar 14a has two second openings 22d which are located on end faces 22g of the body 22. The end faces 22g are generally perpendicular to the longitudinal axis L of the body. It follows that, in the case of the second spacer bar 14 shown in Figure 5, the first openings 22a and second openings 22d are located on perpendicular sides (22e, 22g) of the body 22. As such, the first openings 22a and second openings 22d may be said to be perpendicular. In the present case, the first opening(s) extend through the body 22 in a direction which is substantially perpendicular to the longitudinal axis L of the body, whereas the second openings 22d extend through the body in a direction which is generally parallel to the longitudinal axis L.

The second openings are still required, in use, to adjoin the exterior volume of air.

In the present embodiment there are two second openings 22d - on in each end 22g of the body. In other embodiments, there may only be a second opening in one of the ends 22g. In the present embodiment the second openings are apertures in the ends 22g of the body. In other embodiments the second opening(s) may each comprise an open face/end of the body (e.g. the body may comprise a tube, a pipe or similar with one or two open ends, said one or two open ends constituting one or two second openings respectively).

Figure 6 shows another spacer bar 14b, comprising the hollow body 22 depicted in Figure 4 and an airtight element 80. Figure 6a shows the spacer bar 14b in perspective view, with the airtight element 80 having the same dimensions and shape as the hollow body 22. The hollow body 22 and airtight element 80 are affixed to one another using adhesive, such as double sided glazing tape.

The dashed line depicted on Figure 6a shows the location of cross-section view shown in Figure 6b, which shows the cross section of the airtight element 80 and the interior of the hollow body 22. Hollow body 22 is filled with carbon filter material 24 and comprises openings 22a on the top surface and openings 22b on the bottom surface, as described with reference to Figures 4a and 4b.

The airtight element is adjacent to a side of the hollow body such that the first openings 22a and second openings 22b are not obscured or blocked by the airtight element. It can also be said that the airtight element is located adjacent to a side of the hollow body such that, in use, the airtight element increases a width of the spacer bar in a direction parallel to the direction of separation S between the sheets of glazing material.

Figure 7 shows a further spacer bar 14c, comprising the hollow body 22c depicted in Figure 5 and two airtight elements 80a: one located on each side. Figure 7a shows the spacer bar 14c in perspective view, with each of the airtight elements 80a having the same height as the hollow body 22c, but a reduced width.

The dashed line depicted on Figure 7a shows the location of cross-section view shown in Figure 7b, which shows the airtight elements 80a and interior of the hollow body 22c. Hollow body 22c is filled with carbon filter material 24 and comprises first openings 22a on the top surface and second openings 22d on end faces 22g, as described with reference to Figures 5a and 5b.

The airtight elements are located adjacent opposite sides of the hollow body such that the first openings 22a and second openings 22d are not obscured or blocked by the airtight element. It can also be said that the airtight elements are located adjacent to opposite sides of the hollow body such that, in use, the airtight elements increase a width of the spacer bar in a direction parallel to the direction of separation S between the sheets of glazing material.

The use of one or more airtight elements in combination with a hollow body as part of a spacer bar may be beneficial for several reasons. First, it enables a single type of hollow body to be used in different types of glazing unit having different separations between the glazing panels - the hollow body can be the same in each case, with the different width of the spacer bar corresponding to the different spacing between the glazing panels being achieved by using a different total width of said one or more airtight elements. Secondly, by producing the same hollow body for each type of spacer bar (i.e. for spacer bars of different widths), there may be a reduction in cost of producing the spacer bars due to economies of scale. Thirdly, if the airtight elements are formed from a material which is cheaper than that of the hollow body, then using one or more airtight elements to produce a spacer bar will result in a reduction in the materials cost of the spacer bar. The glazing units and spacer bars outlined above are purely for illustrative purposes and are not intended to be limited. The skilled person may modify the frames according to their knowledge to suit their needs without departing from the scope of the present invention. For example, the skilled person may contemplate the following alternatives and adaptations.

Typically the spacer is elongate and has a rectangular cross-section. The spacer with a rectangular cross-section may have chamfered or rounded edges. The shape of the cross-section is, however, non-limiting, with any uniform cross-section being suitable. Having a body with a uniform cross-section facilitates manufacture, for example by using extrusion processes. This also facilitates fitting of the spacer between the panes of glazing material during manufacture of the glazing unit or retrofit as the constant width of the spacer along its length maintains a constant separation of the panes of glass, keeping the panes of glass parallel to one another. Additionally, having a uniform cross-section also means that the spacer may be cut to a required length.

The cross-section of the spacer may be any shape. Shapes in which there are at least one set of parallel sides are preferred. Cross-sections with parallel sides allow for easy affixing to the panes of glazing material as good contact between the parallel sides of the body and each of the parallel panes of glazing material is assured.

The first opening and/or the second opening may be a plurality of openings. The first opening, or plurality of openings, and the second opening, or plurality of openings, may be on opposite sides of the body. Opposite sides is not intended to mean that the first opening and second opening, or the pluralities thereof, must be in direct opposition to one another, although they may be. Opposite sides is intended to mean that it is possible to divide the cross-section of the body into two continuous, generally equally sized sections, one of which contains only the first opening or plurality of openings and the other of which contains only the second opening or plurality of openings. In this arrangement, it is possible that, when the spacer is positioned between the panes of glass, the first opening, or plurality of openings, adjoins the interior volume, and the second opening, or plurality of openings, adjoins the exterior volume. In a particular embodiment, each plurality of openings is arranged in a single line parallel to the elongate axis of the spacer. In alternative embodiments, each plurality of openings is arranged into two or more lines parallel to the length of the spacer.

The diameter of each opening may be about 0.01 mm to about 5 mm, preferably 0.05 mm to about 2 mm, more preferably about 0.07 to about 1 mm, and most preferably about 0.09 mm to about 0.11 mm. Alternatively, the diameter of each opening may be about 0.05 mm, or about 0.1 mm, or about 0.2 mm, or about 0.3 mm, or about 0.4 mm, or about 0.5 mm. The first and second openings may be of different sizes.

If the first opening and/or second opening is a plurality of openings, the plurality openings may be positioned at a centre-to-centre spacing of about 2mm, about 5mm, about 10 mm, about 15 mm, about 20 mm, about 25 mm, about 30 mm, about 35 mm, about 40 mm, about 45 mm, or about 50 mm. Alternatively, the openings may be positioned at a centre-to-centre spacing of at least one of: in the range of about 2 mm to about 50 mm, or in the range of about 5 mm to about 45 mm, or in the range of about 10 mm to about 40 mm, or in the range of about 15 mm to about 35 mm, or in the range of about 20 mm to about 30 mm.

The first opening and second opening may form a conduit or channel directly through the body. In such embodiments, the filter arrangement is positioned within this conduit or channel.

In some embodiments, the body is hollow and the first opening and second opening are perforations through the surface of the body, thereby connecting the volumes on each side of the body via the hollow of the hollow body. In such embodiments, the filter arrangement may be housed in the cavity of the hollow body.

The body may be made of any material with the necessary physical characteristics to separate the panes of glazing material, maintain the shape of the first openings and second openings therein and retain the filter material. Examples of suitable materials include metals (such as aluminium) and plastics (such as PVC). In preferred embodiments, the body comprises aluminium. The glazing material is typically glass. However, any other suitable glazing material known to the skilled person may be used as an alternative, such as polycarbonates or acrylics.

In order to prevent bowing of the glazing material, the pressures inside and outside of the glazing unit are desirably balanced. In the present invention, this is achieved by allowing air to move between the interior and exterior volumes via the spacer. The air is desirably moved through the spacer at a rate sufficient to prevent a build-up of pressure. Similarly, in order to prevent misting, water vapour is desirably able to move through the spacer at a suitable rate. Allowing the movement of air or water vapour significantly beyond the rates required to achieve the above gives no further advantage and may be detrimental if it enables equilibration of temperature between the interior and exterior volumes.

The rate at which air, or water vapour, can move through the spacer is proportional to the surface area of the first and second openings in the body of the spacer.

Therefore, to achieve the advantageous improvements of the present invention, in certain cases it is not necessary for the spacer to be comprised entirely of the body, and an airtight element (i.e. element through which there is no flow of air between the internal volume and the frame volume) may be included. If included, the airtight element may be affixed to one of the elongated sides of the body and should not block the first or second openings.

In some embodiments which include an airtight element, the ratio of the cross-sectional widths (in a plane perpendicular to the longitudinal axes of the spacer / body / airtight element) of the airtight element and the body is in the range of about 4:1 to 1 :4, preferably in the range of about 3:1 to 1 :3, more preferably in the range of about 2: 1 to 1 :2 and most preferably about 1 :1.

The spacer of the present invention may be made to match the dimensions of conventional spacers. This allows for simple incorporation into existing designs of glazing units without disrupting their production processes, as well as allowing retrofitting of the spacer of the present invention into already fabricated/installed glazing units. Such retrofitting may be performed during repair of failed glazing units. The glazing unit may comprise multiple spacers. Where multiple spacers are used, sealant (e.g. silicone sealant) may be applied to their contact points to avoid unnecessary gaps.

In general, the breathable spacer 14 may be located at any suitable location between the panes of glass, e.g. at the top edge, bottom edge or one of the side edges. It is also contemplated that more than one edge, or only part of one edge, may have a breathable spacer.

As stated above, in order to achieve the advantageous improvements of the present invention, it is only necessary for the body to permit a certain rate of air flow and further air flow may provide no further advantages. Therefore, in some embodiments where multiple spacers are present, less than all (potentially as few as one) of the spacers are required to comprise a body as described above, with the remainder of the spacers being conventional spacers which are impermeable to air. The conventional spacers may comprise foam.

Where a frame is used, the exterior volume is divided into a frame volume defined by the panes of glazing material, the spacer and the frame, and a free volume. Thus there are three volumes in these embodiments: the interior volume (e.g. the volume between the panes of glazing material), the frame volume (e.g. the volume within the frame of the glazing unit) and the free volume (the volume exterior to both the interior volume and frame volume). All three volumes are in fluid communication, via the first, second and third openings, thereby preventing the build-up of water vapour in the interior volume and keeping the pressure equilibrated between all three volumes.

The frame may be comprised of any suitable material. Preferably the frame is comprised of aluminium, PVCu and/or timber. In some embodiments where the frame is comprised of timber and the third opening, or openings, house filter caps, the filter caps may protrude from the surface of the frame to reduce the risk of their accidentally being painted over during routine maintenance.

The third opening may comprise a plurality of openings. The third opening, or openings, may have a diameter of about 1 mm, or about 2 mm, or about 3 mm, or about 4mm, or about 5mm, or about 6 mm or about 7 mm, or about 8 mm or about 9 mm or about 10 mm. Alternatively, the third opening, or openings, may have a diameter in the range of about 1 mm to about 20 mm, about 2 mm to about 15 mm, about 3 mm to about 10 mm, or about 4 mm to about 7 mm.

If the third opening comprises a plurality of openings, the openings may be positioned at a centre-to-centre spacing of at least one of: 100 mm, about 150 mm, about 200 mm, about 250 mm, about 300 mm, about 350 mm, about 400 mm, about 450 mm, or about 500 mm. Alternatively, the openings may be positioned at a centre-to-centre spacing of at least one of: in the range of about 50 mm to about 1000 mm, or in the range of about 100 mm to about 500 mm, or in the range of about 150 mm to about 450 mm, or in the range of about 200 mm to about 400 mm, or in the range of about 250 mm to about 350 mm. The spacing may be in a direction generally parallel to a width of the glazing units.

The third opening, or openings, may house a filter cap. The cap may comprises a coarse filter or a mesh to prevent the ingress of large dust particles, debris and insects into the frame volume of air (and hence the interior volume), as defined above.

The assembly of the glazing unit is advantageously simplified compared to the production of conventional, sealed double glazing units as there is no requirement to form an airtight seal, thereby removing the need for any associated production and testing steps.

Also disclosed herein is a method for the fabrication of the spacer bar. The method comprises the steps of:

a) forming a first opening and a second opening in a body, such that the first and second openings are in fluid communication through the body; and

b) inserting a filter (e.g. filter material) between the first and second openings.

In some embodiments, the first opening and the second opening are formed separately. In other embodiments, the first opening is formed and then extended through the body to form the second opening in a single process. For reasons of simplicity of manufacture, the latter embodiment is preferred. Formation of the first and/or second opening may comprise drilling, punching or other suitable processes known to the skilled person.

In some embodiments, the body is a solid body and in addition to the formation of the first opening and second opening it is also required to form a channel through the body, for example, the drilling of a hole through the body to form the channel. The channel may subsequently be filled with filter material. In other embodiments, the body is a hollow body and the formation of the first opening and second opening comprises perforating opposing faces of the body, allowing fluid communication between the hollow within the hollow body and the volume outside the hollow body. In this latter embodiment, the hollow body may be filled with filter material either before or after the formation of the first opening and second opening.

In a preferred embodiment, a hollow aluminium body is perforated on opposing faces along its length and then filled with filter material.

The method may additionally comprise affixing an airtight (or sealed) component along the length of the body. In preferred embodiments, affixing the sealed component comprises gluing the sealed component to the body.

Also disclosed herein is a method for the fabrication of a glazing unit, the method comprising positioning at least one spacer according to the second aspect of the present invention between two panes of glazing material, wherein the spacer and panes of glazing material define an interior volume, and wherein the first opening adjoins the interior volume, and the second opening adjoins an exterior volume which is exterior to the interior volume.

In some embodiments, affixing the spacer to each of the panes of glass comprises using an adhesive to affix the spacer to each of the panes of glass. In preferred embodiments, the adhesive is a glue, a double-sided glazing tape or a butyl bead. In some embodiments, the method may additionally comprise fitting the assembly comprising the panes of glass and the affixed spacer within a frame. In such embodiments, openings are formed in the external surface of the frame. Preferably the holes in the exterior surface of the frame are fitted with filter caps to prevent the ingress of debris, large particulates of dust and insects into the window frame.

In a preferred embodiment, the frame is a standard aluminium, timber or PVC frame manufactured to take a double or triple glazed unit.

Also disclosed herein is a method of repairing or retrofitting a conventional double- glazing unit comprising two panes of glazing material and at least one conventional spacer defining an interior volume of air, the method comprising the steps of:

a) removing at least one conventional spacer from between the two panes of glass; and

b) positioning a spacer comprising a body comprising a first opening, a second opening and filter therebetween, in the position from which the at least one conventional spacer was removed, wherein the first opening adjoins the interior volume, and the second opening adjoins an exterior volume which is exterior to the interior volume.

Although the filter arrangement in the described embodiments comprises a filter chamber defined by the body and filled with filter material, in other embodiments any appropriate filter arrangement may be used. For example, in some embodiments the spacer may include an in-line filter which is located in the body and which extends between the first and second openings. Depending on the number of first and second openings any appropriate number of in-line filters and/or pipework may be used.

Example

A glazing unit comprising a spacer according to the present invention was fitted to a freezer as part of the freezer door. Within the freezer a halogen lamp was fitted.

The freezer was then subjected to several cycles of cooling, via the normal function of the freezer, and heating, via the halogen lamp. The temperature within the freezer was varied within the range of -12°C to 60°C, while the external room temperature was maintained at a relatively constant 12°C to 14°C. Throughout the experiment no bowing of the glass was observed at any stage.

During the cycles of heating and cooling, the internal temperature of the freezer was held constant at various temperatures and the temperature of the outer pane of glass monitored. This allows for the calculation of the temperature differential which was successfully maintained across the double glazing unit.

The results show that temperature differentials of between 9°C and 29°C were maintained across the glazing unit, demonstrating the significant thermal resistance of glazing units comprising a spacer according to the present invention.

Thermal Resistance Calculation

The total resistance of the construction is calculated to be 1.52 m²K/W, which corresponds to a U value of 0.66 W/m²K. This value compares favourably with high efficiency (i.e. argon gas filled 16 mm gap) conventional double glazing (1.7 W/m²K) and even with triple glazing (0.9 W/m²K). Without wishing to be bound by theory, the applicant believes that the improvement in U value is attributable to the increased width of the air gap, made possible by the spacer bar of the present invention.

Claims

CLAIMS:

1. A glazing unit comprising two panes of glazing material separated by at least one spacer and defining an interior volume, wherein said at least one spacer comprises a body comprising a first opening, a second opening, and a filter arrangement, the at least one spacer disposed such that:

the first opening adjoins the interior volume,

2. The glazing unit according to claim 1 , wherein at least a portion of the filter arrangement is disposed within the body.

3. The glazing unit according to claim 1 or claim 2, wherein the body is hollow, optionally wherein:

a. the hollow body defines at least a portion of the filter arrangement and a filter material of the filter arrangement is located within the hollow body; and/or

b. the hollow body defines a filter chamber of the filter arrangement in fluid communication with the first and second openings, and the filter chamber contains filter material.

4. The glazing unit according to any preceding claim, wherein the filter arrangement comprises a filter material and wherein the filter material is a carbon filter material, optionally wherein the carbon filter material is a compressed carbon impregnated microfibrous foam filter material.

5. The glazing unit according to any preceding claim, wherein the first and/or second opening comprises a plurality of openings.

6. The glazing unit according to any preceding claim, wherein

a. the first and second openings are located on opposite sides of the body; or b. the first and second openings are located on perpendicular sides of the body.

7. The glazing unit according to any preceding claim, wherein the body comprises aluminium.

8. The glazing unit according to any preceding claim, wherein the spacer is elongate and has a generally rectangular cross-section.

9. The glazing unit according to any preceding claim, wherein the spacer further comprises an airtight element affixed to the body, optionally wherein

a. the airtight element comprises aluminium or foam; and/or

b. the airtight element is affixed to the body by an adhesive; and/or c. the airtight element is the same length and/or height as the body.

10. The glazing unit according to any preceding claim, wherein the panes of glazing material are generally parallel to one another and the separation between the panes of glazing material is at least one of: in the range of about 10 mm to about 60 mm, in the range of about 20 mm to about 50 mm, and in the range of about 30 mm to about 40 mm.

11. The glazing unit according to any preceding claim, wherein the spacer defines the separation between the panes of glazing material and wherein opposing faces of the spacer are affixed to the glazing material, optionally wherein the opposing faces of the spacer are affixed to the glazing material using adhesive.

12. The glazing unit according to any preceding claim, wherein the glazing unit further comprises a frame housing the edges of the panes of glazing material, the frame having an internal face and an external face.

13. The glazing unit according to claim 12, wherein the exterior volume is divided into a frame volume defined by the panes of glazing material, the spacer and the frame, and a free volume, and wherein the frame comprises a third opening in fluid communication with the second opening via the frame volume, optionally wherein: a. the third opening is located in the external face; and/or

b. the third opening comprises a plurality of openings; and/or

c. a filter cap is located at the third opening.

14. The glazing unit according to claim 12 or claim 13, wherein the frame is comprised of aluminium, PVC and/or timber.

15. A glazing unit spacer having a body comprising:

a first opening,

a second opening, and

16. The spacer according to claim 15, wherein at least a portion of the filter arrangement is disposed within the body.

17. The spacer according to claim 15 or claim 16, wherein the body is hollow, optionally wherein:

18. The spacer according to any of claims 15 to 17, wherein the filter arrangement comprises a filter material and wherein the filter material is a carbon filter material, optionally wherein the carbon filter material is a compressed carbon impregnated microfibrous foam filter material.

19. The spacer according to any of claims 15 to 18, wherein the first and/or second opening comprises a plurality of openings.

20. The spacer according to any of claims 15 to 19, wherein: a. the first and second openings are located on opposite sides of the body; or

b. the first and second openings are located on perpendicular sides of the body.

21. The spacer according to any of claims 15 to 20, wherein the body comprises aluminium.

22. The spacer according to any of claims 15 to 21 , wherein:

a. the spacer is elongate and has a generally rectangular cross-section, and/or

b. the cross-sectional width of the spacer is at least one of: in the range of about 10 mm to about 60 mm, in the range of about 20 mm to about 50 mm, and in the range of about 30 mm to about 40 mm.

23. The spacer according to any of claims 15 to 22, wherein the spacer further comprises an airtight element affixed to the body, optionally wherein:

a. the airtight element comprises aluminium or foam; and/or

24. A method for fabricating a glazing unit, the method comprising the steps of: positioning at least one spacer according to any of claims 26 to 42 between two panes of glazing material, such that the spacer and panes of glazing material define an interior volume, and such that the first opening adjoins the interior volume, and the second opening adjoins an exterior volume which is exterior to the interior volume.

25. The method according to claim 24, further comprising affixing the spacer to each of the panes of glazing material, optionally wherein the spacer is affixed to each of the panes of glazing material with an adhesive.