AU2019203261B2

AU2019203261B2 - Filter frame for air conditioners

Info

Publication number: AU2019203261B2
Application number: AU2019203261A
Authority: AU
Inventors: Ross Seminara
Original assignee: Healtheair Pty Ltd
Current assignee: Healtheair Pty Ltd
Priority date: 2019-05-09
Filing date: 2019-05-09
Publication date: 2022-11-17
Anticipated expiration: 2039-05-09
Also published as: AU2019203261A1

Abstract

A frame element for supporting a filter element edge, said frame element including a first substantially C-shaped section including a substantially upright web portion and upper and lower flange portions defining a cavity adapted, in use, to receive the filter element edge and retain same by the use of an adhesive that secures the filter element edge inside the cavity, the upper and/or lower flange portion including a lip extending into the cavity which provides a frame element surface area inside the cavity that facilitates bonding between the adhesive and the frame element. / r 4) 1~ 0) U-

Description

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FILTER FRAME FOR AIR CONDITIONERS FIELD OF THE INVENTION

[0001] The present invention relates to an air filter frame for air conditioners that can accommodate filter elements of a variety of thicknesses and that can be used in a variety of return air conditioner grilles of varying dimensions.

BACKGROUND OF THE INVENTION

[0002] Reverse cycle air conditioners in both residential and commercial settings have an air filter element for filtering air before it enters the air conditioning unit. The filter element is usually located within an air return box having a grille. Quite often, the filter element is located directly behind the grille and the filter element must cover the entirety of the grille so that all the air that passes through the grille, only passes through the filter element.

[0003] Air conditioner grilles are typically rectangular in shape with peripheral grooves on three sides to form a filter track into which the edges of a filter element frame may slide to thereby secure the filter element to the grille. In domestic situations at least, the filter tracks of air conditioner grilles are normally about 9-10mm thick. Since the thickness of filter elements tend to vary, replacement of air conditioner filter elements is usually difficult, time consuming and expensive.

[0004] In addition to the varying thickness of filter elements, there exists an additional problem that the size of air conditioner grilles tends to vary between different brands and models that are provided by return air grille suppliers. This also makes it difficult, time consuming and expensive to replace air conditioner filter elements.

[0005] In an attempt to address the abovementioned problems, disposable cardboard framed filters have been proposed. Since disposable cardboard framed filters are easy and comparatively inexpensive to manufacture, it was assumed that they would at least address the problems associated with the difficulty and expense associated with replacing air conditioner filter elements.

[0006] However, it became apparent that due to the inherent structural weakness of the cardboard material, such filters would tend to be weak and would flex, buckle and warp during normal use. Such cardboard framed filters were also observed to have a much shorter lifespan as compared to conventional filter elements thereby requiring same to be replaced more frequently. Accordingly, whilst the cardboard framed filters are disposable and comparatively inexpensive to manufacture, the need to replace same much more frequently as compared to conventional filter elements obviates the advantages associated with such filter frames of being disposable, easy and inexpensive to manufacture.

[0007] Australian Innovation Patent No. 2015101818 discloses a filter frame for air conditioners that seeks to address some of the abovementioned problems. Described in that patent is a rectangular filter frame for air conditioners where the frame includes four frame length pieces and four corner pieces having corresponding interconnecting tabs so that the length pieces and corner pieces can be connected to form a rectangular frame. The connected pieces form a filter track along the internal perimeter for securing an air filter within the frame and a flange is formed along the external perimeter where the flange is of a thickness to be able to interlock with the cavities of an existing air conditioner grille. The flange further includes a dovetail-shaped groove extending along the length piece and corner pieces and is configured to interlock with an insert where the insert includes a dovetail located along the length of the insert configured to engage with the groove by first locating the insert in the groove at a corner piece end and then sliding the insert along the groove until it extends the full length of the length piece and the two corner pieces.

[0008] A problem associated with the filter frame described above is that, over time, the filter medium has been known to become loose from the frame due to glue (used to secure the filter medium) not sticking to the filter track or the bond between the glue and the track weakening after extended use. In these circumstances, because such frames are designed to be disposable since repairing same is cost prohibitive due to the repair being labour intensive and expensive, the entire frame is typically replaced. Hence, there can be a significant labour and cost commitment associated with repairing or replacing filter frames in which the filter media has become loose from the filter tracks.

[0009] Another problem associated with the filter frame described above is the difficulty associated with connecting the insert to the filter frame to extend a particular dimension of the frame. The engagement between a dovetail-shaped groove along the external perimeter of the frame and a correspondingly shaped dovetail associated with the insert can give rise to difficulties in sliding the insert along a length of the frame inside the groove due to a lack of sufficient clearance. This problem is exacerbated by the fact that such frames, including the length and corner pieces, are constructed of plastic material. This has also been known to result in misaligned grooves associated with, for example, a length piece and an adjacent corner piece. When such grooves are misaligned, it can be very difficult to cause an insert to slide beyond a corner piece groove and into the length piece groove, or beyond a length piece groove into the corner piece groove, which increases assembly time.

[0010] The present invention is intended to address at least some of the above problems, or at least provide an alternative to conventional air conditioner filter frames.

[0011] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any suggestion, that the prior art forms part of the common general knowledge at the priority date of the claims herein.

SUMMARY OF THE INVENTION

[0012] In one aspect, the present invention provides a frame element for supporting a filter element edge, said frame element including, a first substantially C shaped section including a substantially upright web portion and upper and lower flange portions defining a cavity adapted, in use, to receive the filter element edge and retain same by the use of an adhesive that secures the filter element edge inside the cavity, the upper and lower flange portions each including, a lip extending into the cavity which provides a frame element surface area inside the cavity that facilitates bonding between the adhesive and the frame element, wherein, the C-shaped section and lip define a first substantially T-shaped slot.

[0013] In an embodiment, the frame element further includes a connector including a second substantially T-shaped slot formed by a second substantially C-shaped section extending in an opposite and substantially parallel direction to the first, substantially C shaped section and arranged such that the web portion of the second substantially C shaped section is substantially parallel with the upright web portion of the first C-shaped section and a flange portion of the second C-shaped section is substantially parallel with the flange portions of the first C-shaped section, the connector configured to engage and retain at least part of an insert for increasing the width of the frame element.

[0014] In an embodiment, the connector engages and retains the insert by means of a corresponding substantially T-shaped projection located on the insert, wherein the T-shaped projection extends along at least part of the insert length.

[0015] In another aspect, the present invention provides a frame assembly for retaining a filter element, the frame assembly including, four frame elements, each frame element including, a first substantially C-shaped section including a substantially upright web portion and upper and lower flange portions defining a cavity adapted, in use, to receive a filter element edge and retain same by the use of an adhesive that secures the filter element edge inside the cavity, the upper and lower flange portions each including a lip extending into the cavity which provides a frame element surface area inside the cavity that facilitates bonding between the adhesive and the frame element, wherein, the C-shaped section and lip define a first substantially T-shaped slot; four corner pieces, each corner piece including two connecting tabs aligned substantially at 90 degrees relative to one another for sliding engagement with corresponding first T-slots located at ends of adjoining frame elements, such that the frame elements, when connected by the corner pieces, together form an assembled frame.

[0016] In embodiment, each corner piece includes two tapered projections aligned substantially at 90 degrees with respect to one another, each tapered projection adapted to be received by a corresponding aperture defined at each end of the frame element.

[0017] In an embodiment, each corner piece includes a corner connector that includes at least one substantially T-shaped slot configured to engage and retain at least part of an insert.

[0018] In an embodiment, the frame assembly further includes a connector located on each of the frame elements including a second substantially T-shaped slot formed by a second substantially C-shaped section extending in an opposite and substantially parallel direction to the first, substantially C-shaped section and arranged such that the web portion of the second substantially C-shaped section is substantially parallel with the upright web portion of the first C-shaped section and a flange portion of the second C shaped section is substantially parallel with the flange portions of the first C-shaped section, the connector configured to engage and retain at least part of an insert for increasing the width of the frame element.

[0019] In an embodiment, the connector engages and retains the insert by means of a corresponding substantially T-shaped projection located on the insert, wherein the T-shaped projection extends along at least part of the insert length.

[0020] In an embodiment, the insert includes a connector with a substantially T shaped slot extending along at least part of the insert length, the connector configured to engage and retain an additional insert by means of a corresponding T-shaped projection located on the additional insert, wherein the T-shaped projection extends along at least part of the additional insert length.

[0021] In another aspect, the present invention provides an insert for increasing the width of a frame element, the insert including a female connecting portion and a male connecting portion; wherein the female connecting portion includes a substantially T shaped slot extending along at least part of the length of the insert for receiving and engaging a corresponding T-shaped projection located on another insert; and wherein the male connecting portion includes a substantially T-shaped projection extending along at least part of the length of the insert for sliding engagement with a corresponding substantially T- shaped slot located on the frame element or another insert.

[0022] In yet another aspect, the present invention provides a frame assembly for retaining a filter element, the frame assembly including, four frame elements, each frame element including, a first substantially C-shaped section including a substantially upright web portion and upper and lower flange portions defining a cavity adapted, in use, to receive a filter element edge and retain same by the use of an adhesive that secures the filter element edge inside the cavity, the upper and lower flange portions each including a lip extending into the cavity which provides a frame element surface area inside the cavity that facilitates bonding between the adhesive and the frame element, wherein, the C-shaped section and lip define a first substantially T-shaped slot; four corner pieces, each corner piece including two connecting tabs aligned substantially at 90 degrees relative to one another for sliding engagement with corresponding first T-slots located at ends of adjoining frame elements, such that the frame elements, when connected by the corner pieces, together form an assembled frame; and one or more inserts adapted for connection to one or more of the frame elements to thereby increase the dimensions of the frame assembly when in an assembled state.

[0023] In an embodiment, each frame element includes a connector including a second substantially T-shaped slot formed by a second substantially C-shaped section extending in an opposite and substantially parallel direction to the first, substantially C shaped section and arranged such that the web portion of the second substantially C shaped section is substantially parallel with the upright web portion of the first C-shaped section and a flange portion of the second C-shaped section is substantially parallel with the flange portions of the first C-shaped section, the connector configured to engage and retain at least part of an insert for increasing the width of the frame element and thereby alter the dimensions of the frame assembly when in an assembled state.

[0024] In an embodiment, the connector engages and retains the insert by means of a corresponding substantially T-shaped projection located on the insert, wherein the T-shaped projection extends along at least part of the insert length.

[0025] In an embodiment, each insert includes a female connecting portion and a male connecting portion; wherein the female connecting portion includes a substantially T-shaped slot extending along at least part of the length of the insert for receiving and engaging a corresponding T-shaped projection located on another insert; and wherein the male connecting portion includes a substantially T-shaped projection extending along at least part of the length of the insert for sliding engagement with a corresponding substantially T- shaped slot located on the frame element or another insert.

[0026] In an embodiment, the T-shaped projection of the male connecting portion includes a dovetail.

[0027] Embodiments of the invention will now be described in further detail with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 illustrates an exploded, top perspective view of a frame assembly and filter element in accordance with an embodiment of the present invention in which the various components of the filter frame assembly are shown in a disassembled state.

[0029] Figure 2 illustrates a top perspective view of a frame element in accordance with an embodiment of the present invention.

[0030] Figure 3 illustrates a top perspective view of a corner piece in accordance with an embodiment of the present invention.

[0031] Figure 4 illustrates a top perspective view of an insert in accordance with an embodiment of the present invention.

[0032] Figure 5 illustrates a top perspective view of an insert of a different width dimension as compared to the insert shown in Figure 4.

[0033] Figure 6 illustrates a sectional view of the inserts shown in Figures 4 and 5.

[0034] Figure 7 illustrates a top view of an assembled filter frame assembly and filter element configured in accordance with an embodiment of the present invention, a sectional view through line A-A, and an enlarged sectional view of portion B of the sectional view.

DETAILED DESCRIPTION OF THE EMBODIMENT(S) OF THE INVENTION

[0035] For convenience, the invention will be described with respect to a particular embodiment, however it will be appreciated by those skilled in the art that the invention is not limited to this particular embodiment.

[0036] Referring to Figure 1, a frame assembly (1) (in a disassembled state) is shown detailing the relationship between the various components of the frame assembly and how these connect to form an assembled frame assembly for retaining a filter element (3). The frame assembly components include frame elements (5) (described in further detail with reference to Figure 2), corner pieces (9) (described in further detail with reference to Figure 3) and inserts (11, 13) (described in further detail with reference to Figures 4 and 5). The one or more inserts (11, 13) may optionally be used when the overall dimension of the frame assembly is desired to be increased, for example, to fit into air conditioner grilles of larger dimension.

[0037] Figure 2 details the features of a frame element (5) including a substantially upright web portion (15) from which an upper flange portion (17) and lower flange portion (19) extend to thereby form a substantially C-shaped section that defines a cavity for receiving a filter element edge (4) of filter element (3) (refer to Figure 1). In the embodiment shown in Figure 1, the filter element (3) and hence the filter element edge (4) are shaped in a V-pleat configuration. This type of filter medium, as compared with a flat filter medium (not shown) for example, increases the surface area that is exposed to air flowing through the frame element by up to three times and gives rise to additional advantages as explained in more detail below. Frame element (5) also includes lip (21) extending into the cavity in which lip (21) together with upright web portion (15), upper flange portion (17), lower flange portion (19) define a first substantially T-shaped slot (22).

[0038] In an embodiment, the frame element (5) may also include a connector (23) with a second substantially T-shaped slot (25) extending in an opposite and substantially parallel direction to the first substantially T-shaped slot (22), and spaced apart from the first substantially T-shaped slot (22) by a hollow spacer element (26). In the embodiment shown, the spacer element (26) has a square cross section, but other shapes and configurations are possible. As with the first substantially T-shaped slot (22), the second substantially T-shaped slot (25) is defined by a substantially C-shaped section including web portion (27) that extends substantially parallel with the upright web portion (15) of frame element (5), and flange portions (29) that extend substantially parallel with the upper flange portion (17) and lower flange portion (19) of the larger C-shaped section of frame element (5). Each flange portion (29) of the connector 23 further includes an associated lip (30) extending along its external edge and in a direction towards one another to thereby form the T-shape of the slot (22).

[0039] The hollow spacer element (26) defines an aperture whose purpose and function is described with reference to Figure 3. In particular, Figure 3 shows corner piece (9) that includes two tapered projections (35) (of which only one is shown in Figure 3) wherein each tapered projection (35) is received by, and interlocks, or otherwise engages with, the aperture defined by the spacer element (26) located on each end of frame elements (5). Spacer element (26) thereby assists in connecting corner piece (9) to frame element (5).

[0040] Corner piece (9) shown in Figure 3 also details connecting tabs (33) that are received by the first T-shaped slots (22) located at ends of adjacent frame elements (5). The connecting tabs (33) are dimensioned to form a tight fit inside T-shaped slots (22). Connecting tabs (33) also thereby assist in connecting corner piece (9) to frame elements (5). In this regard, it will be appreciated that by having connecting tabs (33) in combination with tapered projections (35) on each corner piece (9) serves to strengthen and stabilise the connection between each of the frame elements (5) and corner pieces (9) of the assembled frame.

[0041] Referring still to Figure 3, corner piece (9) includes corner connector (37) having, according to this embodiment, two third T-shaped slots (39) (only one shown) aligned substantially at 90 degrees relative to one another and having substantially the same dimensions as the second T-shaped slot (25) of connector (23) located on frame element (5). It will be appreciated that the dimensions of second and third T-shaped slots (25, 39) located on each of frame element (5) and corner piece (9) respectively are substantially the same in order to accommodate a male connecting portion (45, 53) associated with each insert (11, 13). The purpose and function of the inserts (11, 13) will now be described in further detail with reference to Figures 4 and 5.

[0042] Two exemplary inserts (11, 13) are shown in Figures 4 and 5 respectively in which insert (13) shown in Figure 5 is of a greater width dimension as compared with insert (11) shown in Figure 4. In this regard, it will be appreciated that the purpose and function of inserts (11,13) is to increase the effective width of frame elements (5) in one dimension, thereby increasing the overall dimension of the assembled frame in at least one direction but up to four directions (for a square or rectangular filter frame assembly). It will also be appreciated that inserts (11,13) are merely examples of two inserts having different width dimensions and the present invention contemplates within its scope a variety of inserts of different widths to thereby accommodate air conditioner grilles of different dimensions.

[0043] Referring still to Figures 4 and 5, inserts (11, 13) each have respective female connecting portions (41, 49) and respective male connecting portions (45, 53). Each of the female connecting portions (41, 49) have a substantially T-shaped slot that extends along the length of each insert (11, 13) and which is correspondingly shaped with T-shaped slots (25, 39) located on each of frame element (5) and corner piece (9). Each of the male connecting portions (45, 53) also have a substantially T-shaped projection that extends along the length of each insert (11, 13), each T-shaped projection configured to be received in the second and third T-shaped slots (25, 39) associated with a frame element (5) and corner pieces (9) into which the insert is being attached.

[0044] It will be appreciated that since the T-shaped slots located on each of the frame element connector (25), corner piece connector (37) and female connecting portion of insert (11, 13) are of substantially the same dimensions and correspond to the dimensions of the T-shaped projections located on each of the inserts (11, 13), each insert may be connected to any of the frame elements, corner pieces or another insert as required.

[0045] A sectional view of the inserts (11, 13) is shown in Figure 6 in which a T shaped projection (47, 55) of each respective insert (11, 13) includes a dovetail with respective tapered profiles (47a and 47b, 55a and 55b) and a T-shaped slot (43, 51) configured to receive and engage a T-shaped projection of another insert or frame length piece. The tapered profiles (47a and 47b, 55a and 55b) forming a dovetail on T-shaped projection (47, 55) facilitate insertion of projection (47, 55) into T-shaped slots of frames length pieces, corner pieces or another insert. In this regard, it will be appreciated that the T-shaped slots of the dovetail with tapered profiles (47a and 47b, 55a and 55b) of projection (47, 55) provide sufficient clearance between the periphery of projection (47, ) and the inner surface periphery of the T-shaped slots of frame length pieces, corner pieces and another insert, thereby facilitating insertion of projection (47, 55) into same.

[0046] Whilst not shown in any of the embodiments detailed in the figures herein, it will be appreciated that in an alternative embodiment, the dovetail configuration may be adopted in the T-shaped slots of either the frame length pieces, the corner pieces or inserts, instead of the T-shaped projection of an insert. Accordingly, either the female T shaped slot configured to receive a T-shaped projection of frame length piece, corner piece or an insert will have a dovetail configuration, or alternatively, the T-shaped projection located on an insert will have a dovetail configuration and thereby achieve the same result, that is, the ability to slide a T-shaped projection of an insert into a female T shaped slot located on the frame length pieces and corner pieces without difficulty. The use of a dovetail on either the T-shaped slot or the T-shaped projection (but not both) also obviates the need for precise alignment between the corner pieces and frame length pieces during assembly of the frame.

[0047] Figure 7 shows a top view of an assembled frame assembly including a sectional view through line A-A and an enlarged sectional view of portion B. The assembled frame assembly (1) is configured in accordance with an embodiment of the present invention in which a V-pleated edge (4) of a filter element (3) is retained within the cavity of frame element (5) by means of an adhesive (57). As can be seen from this figure, the upright web portion (15), upper flange portion (17) and lower flange portion (19) of frame element (5) together define a frame of a substantially C-shaped sectional profile. As can also be seen from this figure, adhesive (57) contacts the inner surface of upright web portion (15), and upper flange portion (17) and lower flange portion (19) of frame element (5) in addition to the pleated edge (4) of the filter element (3).

[0048] Figure 7 also clearly details lip (21) extending into the frame element cavity from one or both of upper flange portion (17) and lower flange portion (19) thereby increasing the surface area of frame element (5) that contacts adhesive (57). It will be appreciated that lip (21) not only increases the surface area for bonding but also causes a portion of the hardened adhesive to be retained on the inside of the lip and thereby acts as an anchor. This provides a stronger bond between the frame element and the filter element edge and thereby address problems associated with detachment of filter elements from assembled frames as is typically observed in prior art frame assemblies. The V-pleat shape associated with the edge of filter element (3) also facilitates bonding due to its increased surface area as compared with a flat filter element (3) for example. According to a particular embodiment, the filter element (3) may be manufactured such that there is a 15mm spacing between peaks of the V-pleat and has a 4 micron rating (average size of openings between pieces of the filter medium).

[0049] In operation, corner pieces (9) are attached to frame elements (5) by inserting connecting tabs (33) and tapered projections (35) as shown in Figure 3 into, respectively, slots (22), and apertures defined at each end of frame elements (5) by spacer element (26) as shown in Figure 2. Filter element (3) is then fitted within the cavity of the C-shaped frame element (5) and glued by use of an adhesive to the frame to retain the edge of the filter element (3) within the frame cavity. The edges of the filter element (3) may be hot glued to the frame where the filter is fitted in place and hot glue poured into the cavity to create a seal on either side of the filter, and in the case of a V-pleated filter inside peaks and troughs associated with the V-pleat. According to one embodiment, the adhesive is in the form of polyurethane glue pellets heated to approximately 160 degrees Celsius and pumped along the entire length of the first T-shaped slot (22) using an appropriate glue gun (not shown), ensuring that sufficient glue is pumped to ensure that the lip(s) (21) are immersed inside the glue. The glue then sets and binds the edge (4) of the filter element (5) and ensures there is no air bypass around the filter element (5). The frame element (5) may then be inserted into a filter track of an existing air conditioner grille.

[0050] If the dimensions of the air conditioner grille are greater than the dimensions of the assembled frame (1), inserts (11, 13) can be attached to frame elements (5) (as previously described), thereby effectively increasing the dimension of the connector (23) located on frame element (5) along the dimensions that require extending until the dimensions of the assembled frame substantially match the dimensions of the air conditioner grille. It will be appreciated that the inserts can be measured and easily cut on site to form connectors (23) of suitable dimension. In this regard, it is important that the dimensions of the assembled frame substantially match the dimensions of the filter track of the air conditioner grille so that there are no gaps where the air flow could bypass as it flows through the filter.

[0051] The components of the frame assembly may be made of a suitably rigid material that reduces the likelihood of slots associated with the frame elements (5) and adjacent corner pieces (9) becoming misaligned. For example, each of frame elements may be constructed of an extruded aluminium, and the corner pieces may be constructed of a suitable injection moulded plastic.

[0052] In an embodiment, the inserts have a width of 5 mm or 10 mm, however, it will be appreciated that the inserts may be fabricated to any desired width.

[0053] The frame assembly of the present invention may accommodate a variety of filter elements of different thickness. For example, one suitable filter element may include a 3mm thickness consistency. In an embodiment, the frame element has a width of at least 20mm to 25mm which allows for filter elements of different widths to be accommodated within the frame element cavity.

[0054] The ability to adopt one or more inserts to thereby alter the dimensions of the frame elements provides a versatile frame assembly of which the dimensions may be readily altered and customised, on site, to accommodate air conditioner grilles of different dimensions without the need to use complex tools or machinery.

[0055] Since the frame elements of the present invention are easy to fabricate and may readily accommodate filter elements of different widths, this further adds to the versatility of the frame assembly of the present invention.

[0056] In addition, due to the dovetail tapered profile of the T-shaped projection of male projecting portion of the inserts, insertion of the inserts through the frame length pieces and corner pieces during assembly of the frame is facilitated. The use of a dovetail on the T-shaped projection also obviates the need for precise alignment between the corner pieces and frame length pieces during assembly of the frame.

[0057] Throughout this specification and claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and comprising", will be understood to imply the inclusion of a stated integer or step, or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps.

[0058] It will be appreciated by persons skilled in the relevant field of technology that numerous variations and/or modifications may be made to the invention as detailed in the embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are therefore to be considered in all aspects as illustrative and not restrictive.

Claims

The claims defining the invention are as follows:

1. A frame element for supporting a filter element edge, said frame element including: a first substantially C-shaped section including a substantially upright web portion and upper and lower flange portions defining a cavity adapted, in use, to receive the filter element edge and retain same by the use of an adhesive that secures the filter element edge inside the cavity, the upper and lower flange portions each including: a lip extending into the cavity which provides a frame element surface area inside the cavity that facilitates bonding between the adhesive and the frame element, wherein the C-shaped section and the lip define a first substantially T-shaped slot.

2. A frame element according to claim 1, further including: a connector including a second substantially T-shaped slot formed by a second substantially C-shaped section extending in an opposite and substantially parallel direction to the first substantially C-shaped section, and arranged such that the web portion of the second substantially C-shaped section is substantially parallel with the upright web portion of the first C-shaped section, and a flange portion of the second C shaped section is substantially parallel with the flange portions of the first C-shaped section, the connector configured to engage and retain at least part of an insert for increasing the width of the frame element.

3. A frame element according to claim 2, wherein the connector engages and retains the insert by means of a corresponding substantially T-shaped projection located on the insert, wherein the T-shaped projection extends along at least part of the insert length.

4. A frame assembly for retaining a filter element, the frame assembly including: four frame elements, each frame element including: a first substantially C-shaped section including a substantially upright web portion and upper and lower flange portions defining a cavity adapted, in use, to receive a filter element edge and retain same by the use of an adhesive that secures the filter element edge inside the cavity, the upper and lower flange portions each including a lip extending into the cavity which provides a frame element surface area inside the cavity that facilitates bonding between the adhesive and the frame element, wherein the C-shaped section and the lip define a first substantially T-shaped slot; four corner pieces, each corner piece including two connecting tabs aligned substantially at 90 degrees relative to one another for sliding engagement with corresponding first T-slots located at ends of adjoining frame elements, such that the frame elements, when connected by the corner pieces, together form an assembled frame.

5. A frame assembly according to claim 4, wherein each corner piece includes two tapered projections aligned substantially at 90 degrees with respect to one another, each tapered projection adapted to be received by a corresponding aperture defined at each end of the frame element.

6. A frame assembly according to either claim 4 or claim 5, wherein each corner piece includes a corner connector that includes at least one substantially T-shaped slot configured to engage and retain at least part of an insert.

7. A frame assembly according to any one of claims 4 to 6, further including: a connector located on each of the frame elements including a second substantially T-shaped slot formed by a second substantially C-shaped section extending in an opposite and substantially parallel direction to the first substantially C-shaped section, and arranged such that the web portion of the second substantially C-shaped section is substantially parallel with the upright web portion of the first C-shaped section, and a flange portion of the second C-shaped section is substantially parallel with the flange portions of the first C-shaped section, the connector configured to engage and retain at least part of an insert for increasing the width of the frame element.

8. A frame assembly according to claim 7, wherein the connector engages and retains the insert by means of a corresponding substantially T-shaped projection located on the insert, wherein the T-shaped projection extends along at least part of the insert length.

9. A frame assembly according to claim 7 or claim 8, wherein the insert includes a connector with a substantially T-shaped slot extending along at least part of the insert length, the connector configured to engage and retain an additional insert by means of a corresponding T-shaped projection located on the additional insert, wherein the T-shaped projection extends along at least part of the additional insert length.

10. A frame assembly for retaining a filter element, the frame assembly including: four frame elements, each frame element including: a first substantially C-shaped section including a substantially upright web portion and upper and lower flange portions defining a cavity adapted, in use, to receive a filter element edge and retain same by the use of an adhesive that secures the filter element edge inside the cavity, the upper and lower flange portions each including a lip extending into the cavity which provides a frame element surface area inside the cavity that facilitates bonding between the adhesive and the frame element, wherein the C-shaped section and the lip define a first substantially T-shaped slot; four corner pieces, each corner piece including two connecting tabs aligned substantially at 90 degrees relative to one another for sliding engagement with corresponding first T-slots located at ends of adjoining frame elements, such that the frame elements, when connected by the corner pieces, together form an assembled frame; and one or more inserts adapted for connection to one or more of the frame elements to thereby increase the dimensions of the frame assembly when in an assembled state.

11. A frame assembly according to claim 10, wherein each frame element includes a connector including a second substantially T-shaped slot formed by a second substantially C-shaped section extending in an opposite and substantially parallel direction to the first substantially C-shaped section, and arranged such that the web portion of the second substantially C-shaped section is substantially parallel with the upright web portion of the first C-shaped section, and a flange portion of the second C shaped section is substantially parallel with the flange portions of the first C-shaped section, the connector configured to engage and retain at least part of an insert for increasing the width of the frame element and thereby alter the dimensions of the frame assembly when in an assembled state.

12. A frame assembly according to claim 11, wherein the connector engages and retains the insert by means of a corresponding substantially T-shaped projection located on the insert, wherein the T-shaped projection extends along at least part of the insert length.

13. A frame assembly according to claim 10 or claim 11, wherein each insert includes a female connecting portion and a male connecting portion; wherein the female connecting portion includes a substantially T-shaped slot extending along at least part of the length of the insert for receiving and engaging a corresponding T-shaped projection located on another insert; and wherein the male connecting portion includes a substantially T-shaped projection extending along at least part of the length of the insert for sliding engagement with a corresponding substantially T- shaped slot located on the frame element or another insert.

14. A frame assembly according to claim 12 or claim 13, wherein the T-shaped projection of the insert includes a dovetail.