GB2621624A

GB2621624A - Installing a window assembly

Info

Publication number: GB2621624A
Application number: GB2212065.3A
Authority: GB
Inventors: Cobbing Colin; Taylor Marc
Original assignee: Acoustic Facades Ltd
Current assignee: Acoustic Facades Ltd
Priority date: 2022-08-18
Filing date: 2022-08-18
Publication date: 2024-02-21
Also published as: GB202212065D0

Abstract

An apparatus or method of installing a window assembly, which has an outer window frame and an inner window frame both with a fixed glaze panel 18, 24 and a sliding sash 20, 26. The inner and outer window frames are spaced apart to create a cavity between them and the slidable sashes create an inlet 40 and an outlet 42. The installation method includes the steps of: detecting ambient noise levels to identify a noise source; determining an elevation of the noise source relative to the elevation of an opening in a building; and selecting the positions of a window inlet and outlet based on the elevation of the sound or noise source. The inlet and outlet may be vertically or horizontally offset and there may be an acoustic deflecting element 50 which deflects sounds waves. There may also be an acoustic attenuation or reducing member 46 positioned within the cavity. A window assembly is also claimed which includes the acoustic attenuation member.

Description

Installing a Window Assembly

FIELD

The present teachings relate to a method of installing a window assembly, and to a window assembly for installation in an opening of a building structure.

BACKGROUND

Noise is simply sound that is loud or unpleasant or causes disturbances. Living in certain environments, for example an urban environment, noise levels can become extremely annoying or even harmful, and affect both your life and your health.

In order to combat this ambient noise, window assemblies installed in the openings of buildings are constructed to limit the amount of noise that is transmitted therethrough to the interior of the building. Window assemblies often include two or more facing panes of glass or other material separated by an air space so as to reduce the noise transmission to which the window assembly is mounted. These known window assemblies are often unopenable so as to be able to provide the required levels of noise insulation, and may provide insufficient noise insulation when one or more of the window frames are opened.

The present teachings seek to overcome or at least mitigate one or more problems associated with the prior art.

SUMMARY

According to a first aspect there is provided a method of installing a window assembly into an opening of a building structure, the window assembly provided in the form of an outer window and an inner window spaced apart to define a cavity therebetween, the inner window comprising an outboard frame defining a first outer opening comprising a first outer fixed window portion and a first outer slideable window sash mounted therein and the inner window comprising an inboard frame defining a first inner opening comprising a first inner fixed window portion and a first inner slideable window sash mounted therein, wherein the first outer window sash and first inner window sash are slideably mounted to the outboard and inboard frames to be openable to define an inlet and an outlet defining a sound transmission path between the inlet and outlet, respectively, the method comprising the steps of: detecting ambient noise levels at the opening of the building to identify a noise source; determining an elevation of the noise source relative to an elevation of the opening of the building; selecting positions of the inlet and outlet based on the determined elevation of the noise source such that the inlet is positioned on the outboard frame to be remote from the identified noise source; and slidably mounting the first outer window sash and first inner window sash in their selected positions on the outboard frame and inboard frame, respectively.

This method of assessing the noise at a particular location prior to installation, and subsequent configuration of the window assembly based on this assessment enables the acoustic attenuation of the window assembly to be tailored to the noise conditions at the installation location, by providing a tortuous sound transmission path.

The step of selecting the position of the inlet and outlet may comprise the step of positioning the outlet to be vertically offset from the inlet.

This increases the sound transmission path through the window assembly, and so provides a more tortuous sound transmission path, which works to further attenuate noise travelling therethrough.

When the elevation of the noise source is less than the elevation of the opening of the building, the method may comprise the step of slidably mounting the first slideable outer window sash to the outboard frame so as to be positioned above the first outer fixed window portion, when the first slideable outer window sash is in a closed position.

This arrangement positions the inlet proximate to an upper edge of the window assembly when the noise source is below the window assembly. This has been found to increase diffraction losses about the edge of the first outer window sash, which further improves acoustic attenuation of the window assembly. Positioning the inlet facing away from the noise source has been found to provide a tortuous sound transmission path and to increase direction losses about the edge of the first outer window sash.

The method may comprise the step of slidably mounting the first slideable inner window sash to the inboard frame so as to be below the first inner fixed window portion, when the first slideable inner window sash is in a closed position.

When the elevation of the noise source is determined to be greater than the elevation of the opening of the building, the method may comprise the step of slidably mounting the first slideable outer window sash to the outboard frame to be positioned below the first outer fixed window portion, when the first slideable outer window sash is in a closed position.

This arrangement positions the inlet proximate to a lower edge of the window assembly when the noise source is above the window assembly. This has been found to increase diffraction losses about the edge of the first outer window sash, which further improves acoustic attenuation of the window assembly. Positioning the inlet facing away from the noise source has also been found to increase direction losses about the edge of the first outer window sash.

The method may comprise the step of slidably mounting the first slideable inner window sash to the inboard frame so as to be positioned above the first inner fixed window portion, when the first slideable inner window sash is in a closed position.

The method may comprise the step of configuring the first outer window sash to deflect sound waves travelling from the identified noise source away from the inlet.

This has been found to increase diffraction losses about the edge of the first outer window sash, which further improves acoustic attenuation of the window assembly.

The method may comprise the step of connecting an acoustic deflecting member to the window assembly, the acoustic deflecting member configured and arranged to deflect sound waves travelling from the identified noise source away from the inlet.

The method may comprise the step of arranging the acoustic deflecting member to at least partially obscure or cover the inlet relative to the identified noise source.

The method may comprise the step of arranging the acoustic deflecting member to project outwardly from the outer window in a direction away from the inner window.

The method may comprise the step of arranging the acoustic deflecting member such that a distal end region of the acoustic deflecting member is arranged to extend in a direction substantially away from the first inner fixed window portion.

The method may comprise the steps of calculating a desired amount of noise attenuation required at the opening of the building, and providing one or more acoustic attenuation members between the outer window and the inner window such that the window assembly provides the desired noise attenuation.

These steps help to ensure that the window assembly is able to provide the desired level of noise attenuation for a particular location. Providing only the required level of noise attenuation helps to ensure that the cavity is not unnecessarily filled with acoustic attenuation members, which would be detrimental to flow through the window assembly.

The method may comprise the step of arranging the one or more acoustic attenuation members to restrict the sound transmission path and/or to increase the length of the sound transmission path between the inlet and outlet.

The method may comprise the step of arranging the one or more acoustic attenuation members to provide a more tortuous sound transmission path.

Through this arrangement, the acoustic attenuation members are configured and arranged so as to provide a more tortuous sound transmission path from the inlet to the outlet of the window assembly.

The method may comprise the step of arranging the one or more acoustic attenuation members to divide the cavity into one or more window chambers along the sound transmission path from the inlet to the outlet.

The method may comprise the step of arranging the one or more acoustic attenuation members along the inner edges of the window cavity.

The method may comprise the step of arranging a first acoustic attenuation member in the cavity to extend laterally between the inner window and the inner window, the first acoustic attenuation member configured to restrict the sound transmission path.

The first acoustic attenuation member may comprise a housing that is at least partially filled with an acoustic attenuating material.

The acoustic attenuating material may be arranged to define an air flow duct therethrough.

The air flow duct may b stepped, substantially V-shaped, or substantially U-shaped.

The housing may defines a housing inlet and a housing outlet aligned with upstream and downstream openings of the air flow duct.

The housing inlet and housing outlet may be defined by one or more apertures in the housing.

The method may comprise the step of positioning the outlet to be horizontally offset from the inlet.

The method may comprise the step of arranging a second acoustic attenuation member in the cavity to extend substantially vertically, in use, between the outer window and the inner window to increase the length of the sound transmission path between the inlet and outlet.

The method may comprise the step of assessing a building structure in which the window assembly is to be installed. When the window assembly is to be installed in combination with one or more balconies, e.g. acoustic balconies, the method may comprise the step of selecting positions of the inlet and outlet based on the determined elevation of the noise source such that the inlet is positioned on the outboard frame to be proximate to the identified noise source.

When the elevation of the noise source is less than the elevation of the opening, and the window assembly may be installed in combination with one or more balconies, the method may comprise the step of mounting the first outer window sash to the outboard frame so as to pivot about an upper edge thereof, e.g. in a direction away from the inboard frame, to define the inlet.

When the elevation of the noise source is greater than the elevation of the opening, and the window assembly may be installed in combination with one or more balconies, the method may comprise the step of mounting the first outer window sash to the outboard frame so as to pivot about a lower edge thereof, e.g. in a direction towards the inboard frame, to define the inlet.

The inlet may be positioned at or near an upper edge or lower edge of the outboard frame when the elevation of the noise source is greater than or less than the elevation of the opening, respectively, when the window assembly is installed in combination with one or more balconies.

Due to the acoustic blocking provided by upper and/or lower acoustic balconies, this has been found to provide increased acoustic attenuation for a window assembly that is installed between upper and lower acoustic balconies.

According to a second aspect, there is provided a window assembly for installing into an opening of a building structure, the window assembly comprising: an outer window comprising an outboard frame defining a first outer opening, and a first outer fixed window portion and a first outer slideable window sash mounted in the first outer opening, the first outer slideable window sash being slideably mounted to the outboard frame to be openable, in use, to define an inlet; and an inner window comprising an inboard frame defining a first inner opening, and a first inner fixed window portion and a first inner slideable window sash mounted in the first inner opening, the first inner slideable window sash being slideably mounted to the inboard frame to be openable, in use, to define an outlet, wherein the outer window is spaced apart from the inner window to define a cavity therebetween, and wherein the window assembly comprises a first acoustic attenuation member connected to the inner window and the outer window and arranged in the cavity to extend laterally across the cavity to restrict a sound transmission path between the inlet and outlet.

The first acoustic attenuation member may be connected to the first outer fixed window portion and the first inner fixed window portion.

The first acoustic attenuation member may comprises a housing that is at least partially filled with an acoustic attenuating material.

Improved acoustic attenuation.

The acoustic attenuating material may be arranged to define an air flow duct 30 therethrough.

This provides a more tortuous sound transmission path.

The air flow duct may be stepped, substantially V-shaped, or substantially U-shaped.

This provides a more tortuous sound transmission path.

The housing may define a housing inlet and a housing outlet aligned with upstream and downstream openings of the air flow duct.

The inlet and the outlet are vertically offset, in use.

One of the first outer slideable window sash and first inner slideable window sash may be mounted such that it is positioned above the respective first outer fixed window portion or first inner fixed window portion, when in the closed position.

The other of the first outer slideable window sash and first inner slideable window sash may beis mounted such that it is positioned below the respective first outer fixed window portion or first inner fixed window portion, when in the closed position.

The inlet and the outlet may be horizontally offset, in use.

This provides a more tortuous sound transmission path.

The window assembly may comprise a second acoustic attenuation member arranged in the cavity to extend substantially vertically, in use, between the outer window and the inner window and configured and arranged to increase the length of the sound transmission path between the inlet and outlet.

This provides a more tortuous sound transmission path.

The window assembly may comprise one or more further acoustic attenuation members arranged in the cavity to restrict the sound transmission path and/or to increase the length of the sound transmission path between the inlet and outlet.

The window assembly may comprise an acoustic deflecting member configured and arranged to deflect sound waves travelling from an identified noise source away from the inlet.

The acoustic deflecting member may be configured and arranged to at least partially obscure or cover the inlet.

The acoustic deflecting member may be an angled or curved plate member.

The acoustic deflecting member may be configured and arranged to project outwardly from the outer window in a direction away from the inner window.

The acoustic deflecting member may be substantially L-shaped or curved.

The acoustic deflecting member may comprise a distal end region that is arranged to extend in a direction substantially away from the first inner fixed window portion.

The acoustic deflecting member may extend across substantially all of the inlet. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 is a view of an external face of a window assembly according to an embodiment; Figure 2 is a view of an internal face of the window assembly of Figure 1; Figure 3 is a vertical cross-sectional view of the window assembly of Figure 1; Figure 4 is a view of an external face of a window assembly according to an embodiment; Figure 5 is a view of an internal face of the window assembly of Figure 4; and Figure 6 is a vertical cross-sectional view of the window assembly of Figure 4.

DETAILED DESCRIPTION OF EMBODIMENT(S)

Referring to Figures 1 to 6, a window assembly for installing into an opening of a building structure (not shown) is illustrated and indicated generally at 10. The window assembly 10 includes an inner window and an outer window spaced apart to define a cavity therebetween. The window assembly includes a frame. The inner window includes an inboard frame 12 and the outer window includes an outboard frame 14. The inboard frame 14 is connected, i.e. structurally connected, to the outboard frame 12. Put another way, the window assembly 10 is a box shaped window assembly formed from an outer window 12 connected, and spaced apart from, an inner window 14.

The outboard frame 12 is formed from upper 27, lower 28, and two side 29, 30 members. The members 27, 28, 29, 30 are arranged to form a substantially rectangular frame. The inboard frame 14 is formed from upper 32, lower 34, and two side 36, 38 members. The members 32, 34, 36, 38 are arranged to form a substantially rectangular frame.

The outboard frame 12 defines a first outer opening 16. A first outer fixed window portion 18 and a first outer slideable window sash 20 are mounted to the outboard frame 12 in the first outer opening 16. The inboard frame 14 defines a first inner opening 22. A first inner fixed window portion 24 and a first outer slideable window sash 26 are mounted to the inboard frame 12 in the first inner opening 22. In alternative arrangements, only a single frame may be provided, and the first outer fixed window portion 18, the first outer slideable window sash 20, the first inner fixed window portion 24, and the first outer slideable window sash 26 may be mounted to the frame and spaced apart to define the cavity.

The first outer window sash 20 is slideably mounted to the outboard frame 12. The first outer window sash 20 is slideable/openable to define an inlet 40. The first inner window sash 26 is slideably mounted to the inboard frame 14. The first inner window sash 26 is slideable/openable to define an outlet 42. In this way, the window assembly 10 defines a sound transmission path 44 through the window assembly 10 from the external inlet 40 to the internal outlet 42.

The first inner window sash 20 and first outer window sash 26 are arranged so as to slide within the respective frame 12, 14 along a direction that is intended to be substantially vertical, in use. Put another way, the first inner window sash 20 and first outer window sash 26 are arranged so as to slide along a substantially upright axis (i.e. between upper 27, 32 and lower 28, 34 members of the respective frame 12, 14), in use. Although not illustrated, the first inner window sash 20 and first outer window sash 26 may be received in elongate tracks, guides, or grooves provided on inner faces of the opposing side members 29, 30, 36, 38 of the respective frame 12, 14.

The inlet 40 and outlet 42 are offset. The inlet 40 and outlet 42 may be vertically and/or horizontally offset. In the illustrated window assembly, the first inner window sash 20 and first outer window sash 26 are arranged so as to vertically offset. Put another way, the inlet 40 and the outlet 42 are arranged so as to be vertically offset. Although not illustrated, it will be appreciated that in some alternative arrangements, the window assembly 10 may include further fixed window portions adjacent to the first fixed window portions and first window sashes, and in such arrangements, the inlet and the outlet may also be arranged to be horizontally offset. Offsetting the inlet 40 and the outlet 42 works to increase the length of the sound transmission path 44 through the window assembly, and to provide a more tortuous sound transmission path 44 through the window assembly.

In the illustrated arrangements, one of the first outer window sash 20 and first inner window sash 26 is mounted such that it is positioned above the respective first outer fixed window portion 18 or first inner fixed window portion 24, when in the closed position. The other of the first outer window sash 20 and first inner window sash 26 is mounted such that it is positioned below the respective first outer fixed window portion 18 or first inner fixed window portion 24, when in the closed position.

In the arrangement shown in Figures 1 to 3, the first outer window sash 20 is positioned below the first outer fixed window portion 18, when in the closed position, and the first inner window sash 26 is positioned above the first inner fixed window portion 24, when in the closed position. This arrangement positions the inlet 40 in a lower region of the window assembly. This arrangement has been found to be particularly advantageous when the elevation of the noise source, in the location where the window assembly 10 is installed, is greater than the elevation of the window assembly 10. This arrangement provides effective acoustic attenuation of the window assembly 10 for noise that is coming from above the window assembly, e.g. from airplanes.

In the arrangement shown in Figures 4 to 6, the first outer window sash 20 is positioned above the first outer fixed window portion 18, when in the closed position, and the first inner window sash 26 is positioned below the first inner fixed window portion 24, when in the closed position. This arrangement positions the inlet 40 in an upper region of the window assembly. This arrangement has been found to be particularly advantageous when the elevation of the noise source, in the location where the window assembly 10 is installed, is less than the elevation of the window assembly 10. This arrangement provides effective acoustic attenuation of the window assembly 10 for noise that is coming from below the window assembly, e.g. from people and/or road vehicles.

The window assembly 10 includes one or more acoustic attenuation members arranged in the cavity and extending between the outer window and the inner window. The acoustic attenuation members are configured to attenuate and/or absorb sound travelling along the sound transmission path 44. The acoustic attenuation members restrict the sound transmission path and/or increase the length of the sound transmission path between the inlet and outlet. The one or more acoustic attenuation members are arranged within the cavity to divide the cavity into one or more window chambers along the sound transmission path from the inlet 40 to the outlet 42. In the illustrated arrangements, the cavity is divided into two chambers, but it will be appreciated that any suitable number of chambers may be formed.

In the illustrated arrangement, the window assembly 10 includes a first acoustic attenuation member 46 arranged in the cavity to extend laterally between the outer window and the inner window. The first acoustic attenuation member 46 extends across an entirety of the cavity. Put another way, the first acoustic attenuation member 46 extends between the side members of the frame or frames. The first acoustic attenuation member 46 extends between and is connected to the first outer fixed window portion 18 and first inner fixed window portion 24. The first acoustic attenuation member 46 is positioned horizontally to restrict flow vertically flow within the cavity (i.e. between upper and lower chambers of the window assembly). Whilst the first attenuation member 46 has been described as a single attenuation member, it will be appreciated that it may be formed from a plurality of attenuation members arranged adjacently in the cavity. The first acoustic attenuation members 46 extend between lateral sides of the cavity. The first acoustic attenuation member 46 is configured to enable air to flow there through, but to restrict the transmission of sound waves therethrough, so as to attenuate the sound waves (i.e. noise) as it passes through the window assembly 10.

The first acoustic attenuation member 46 is formed from an acoustic attenuation material. The first acoustic attenuation member 46 may include an air flow duct therethrough that is defined by the acoustic attenuating material. The air flow duct through the first acoustic attenuation member 46 may be stepped, may be substantially V-shaped, or substantially U-shaped, and arranged within the cavity to enable air to pass therethrough. This works to attenuate noise whilst enabling transmission through the acoustic attenuation member 46. The first acoustic attenuation member 46 may include a housing. In some arrangements, the housing may be omitted. The housing may define a housing inlet and a housing outlet. The housing inlet and housing outlet may be aligned with upstream and downstream openings of the air flow duct. The housing of the first acoustic attenuation members 46 may include one or more apertures to define the housing inlet and/or one or more apertures to define the housing outlet. The housing may include apertures as an array over the housing, e.g. over an entirety of the housing.

In arrangements where the inlet and the outlet are horizontally offset, one or more acoustic attenuation members may be arranged vertically. The vertical acoustic attenuation members may be arranged to prevent or restrict lateral flow in a region of the cavity to increase the length of the sound transmission path 44. Each vertical acoustic attenuation member may be formed from an acoustic attenuating material. The acoustic attenuating members may include a housing defining a housing inlet and a housing outlet. The housing may be partially filled with an acoustic attenuation material to define an attenuating sound transmission path therethrough. The sound transmission path through the or each vertical acoustic attenuation member may be substantially V-shaped, or substantially U-shaped. This works to attenuate noise without enabling transmission through the vertical acoustic attenuation member 38.

Although not illustrated, one or more acoustic attenuation members may also be positioned along the lateral sides of the cavity. These may be substantially the same as the vertical acoustic attenuation members, or may be provided in the form of an elongate body of acoustic attenuation material.

The window assembly 10 is provided with an acoustic deflecting member 48. The acoustic deflecting member 48 may be connected to the first outer window sash 20 (as shown in Figures 1 to 3) or may be connected to the outboard frame 12 (as shown in Figure 1 to 3). In some arrangements, the acoustic deflecting member may be mounted to the opening of the building. The acoustic deflecting member 48 is configured to deflect sound waves (i.e. noise) away from the inlet 40. The deflecting member 48 extends laterally across the window assembly 10. The acoustic deflecting member 48 is arranged proximate to the inlet 40. The acoustic deflecting member 48 is configured and arranged to at least partially obscure or cover the inlet 40.

The deflecting member 48 projects outwardly from the outer window (e.g. from the first outer window sash 20). The deflecting member 48 projects in a direction away from the inner window. In the illustrated arrangement, the acoustic deflecting member 48 is substantially L-shaped. In alternative arrangements, the acoustic defecting member may be curved, or may be any other suitable shape. The acoustic deflecting member may be an angled or curved plate member. The acoustic deflecting member includes a distal end region 50 that is arranged to extend in a direction substantially away from the first inner fixed window portion 18 to at least partially cover the inlet 40.

Although not illustrated, the window assembly 10 may be installed in a building structure. The building structure including one or more walls defining an opening therein. The window assembly will be installed within the opening.

In some arrangements, one or more balconies may be mounted to the wall, for example upper and lower balconies. The one or more balconies may be considered to be acoustic balconies. When the window assembly 10 is installed in combination with one or more balconies, e.g. acoustic balconies, the inlet 40 is positioned on the outboard frame to be proximate to the identified noise source. Put another way, the inlet 40 is positioned at or near an upper edge or lower edge of the outboard frame 12 when the elevation of the noise source is greater than or less than the elevation of the opening, respectively, when the window assembly 10 is installed in combination with one or more balconies.

The window assembly 10 may be configured to deflect sound waves (i.e. noise) away from the inlet 40. The window assembly 10 achieves this by increasing diffraction losses about an edge of the first outer window sash 20.

A method of installing the window assembly 10 into an opening of a building structure will now be discussed.

In order to tailor the acoustic attenuation of the window assembly 10 for the noise levels in a particular location, the following method of installation is described.

The method of installation includes: detecting ambient noise levels at the opening of the building to identify a noise source; determining an elevation of the noise source relative to an elevation of the opening of the building; selecting positions of the first outer window sash 20 and first inner window sash 26 based on the determined elevation of the noise source; and slidably mounting the first outer window sash 20 and first inner window sash 26 in their selected positions on the outboard frame 12 and inboard frame 14, respectively.

When the elevation of the noise source is less than the elevation of the opening, the first outer window sash 20 is installed to be positioned above the first outer fixed window portion 18. This positions the inlet 40 to be remote from the identified noise source, and tailors the window assembly 10 to more effectively attenuate noise that is coming from below the window assembly 10, e.g. from people and/or road vehicles.

When the elevation of the noise source is determined to be greater than the elevation of the opening of the building, the first outer window sash 20 is installed to be positioned below the first outer fixed window portion 18. This positions the inlet 40 to be remote from the identified noise source, and tailors the window assembly 10 to more effectively attenuate noise that is coming from above the window assembly 110, e.g. from airplanes.

The method may include the step of calculating a desired amount of noise attenuation/reduction required at the opening of the building. The method will then also include the step of providing one or more acoustic attenuation members between the outer window and the inner window such that the window assembly 10 provides the desired noise attenuation. These steps help to ensure that the window assembly 10 is able to provide the desired level of noise attenuation for a particular location. Providing only the required level of noise attenuation helps to ensure that the cavity is not unnecessarily filled with acoustic attenuation members, which would be detrimental to flow through the window assembly 10.

The method may include the step of arranging a first acoustic attenuation member 46 in the cavity to extend laterally between the inner window and the inner window.

The first acoustic attenuation member 46 may be configured to restrict the sound transmission path.

The acoustic attenuation member may be formed from an attenuating material that is arranged to define an air flow duct therethrough. The air flow duct is stepped, substantially V-shaped, or substantially U-shaped. The first acoustic attenuation member may have a housing that is at least partially filled with an acoustic attenuating material. The housing may define a housing inlet and a housing outlet aligned with upstream and downstream openings of the air flow duct.

The method may include assessing a building structure in which the window assembly is to be installed to determine if the window assembly is to be installed in combination with one or more, e.g. upper and lower, balconies. In such arrangement, the method will include the step of selecting positions of the inlet and outlet based on the determined elevation of the noise source such that the inlet is positioned on the outboard frame to be proximate to the identified noise source.

The method may include the step of configuring the first outer window sash 20 to deflect sound waves travelling in a direction from the noise source away from the inlet 40.

The method may include arranging the acoustic deflecting member to at least partially obscure or cover the inlet relative to the identified noise source and/or to project outwardly from the outer window in a direction away from the inner window.

The method may include the step of restricting the sound transmission path 44. The method may include the step of increasing the length of the sound transmission path 44 between the inlet 40 and outlet 42. The sound transmission path 44 may be restricted and/or lengthened by arranging one or more acoustic attenuation members arranged in the cavity. Put another way, the method may include arranging one or more acoustic attenuation members in the cavity to provide a more tortuous sound transmission path from the inlet 40 to the outlet 42 of the window assembly 10.

Although the teachings have been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope as defined in the appended claims.

Claims

Claims 1. A method of installing a window assembly into an opening of a building structure, the window assembly provided in the form of an outer window and an inner window spaced apart to define a cavity therebetween, the inner window comprising an outboard frame defining a first outer opening comprising a first outer fixed window portion and a first outer slideable window sash mounted therein and the inner window comprising an inboard frame defining a first inner opening comprising a first inner fixed window portion and a first inner slideable window sash mounted therein, wherein the first outer window sash and first inner window sash are slideably mounted to the outboard and inboard frames to be openable to define an inlet and an outlet defining a sound transmission path between the inlet and outlet, respectively, the method comprising the steps of: detecting ambient noise levels at the opening of the building to identify a noise source; determining an elevation of the noise source relative to an elevation of the opening of the building; selecting positions of the inlet and outlet based on the determined elevation of the noise source such that the inlet is positioned on the outboard frame to be remote from the identified noise source; and slidably mounting the first outer window sash and first inner window sash in their selected positions on the outboard frame and inboard frame, respectively.
2. The method according to claim 1, selecting the position of the inlet and outlet comprises the step of positioning the outlet to be vertically offset from the inlet.
3. The method according to claim 1 or claim 2, wherein, when the elevation of the noise source is less than the elevation of the opening of the building, the method comprises the step of slidably mounting the first slideable outer window sash to the outboard frame so as to be positioned above the first outer fixed window portion, when the first slideable outer window sash is in a closed position.
4. The method according to claim 3, comprising the step of slidably mounting the first slideable inner window sash to the inboard frame so as to be below the first inner fixed window portion, when the first slideable inner window sash is in a closed position.
5. The method according to any preceding claim, wherein, when the elevation of the noise source is determined to be greater than the elevation of the opening of the building, the method comprises the step of slidably mounting the first slideable outer window sash to the outboard frame to be positioned below the first outer fixed window portion, when the first slideable outer window sash is in a closed position.
6. The method according to claim 5, comprising the step of slidably mounting the first slideable inner window sash to the inboard frame so as to be positioned above the first inner fixed window portion, when the first slideable inner window sash is in a closed position.
7. The method according to any preceding claim, comprising the step of connecting an acoustic deflecting member to the window assembly, the acoustic deflecting member configured and arranged to deflect sound waves travelling from the identified noise source away from the inlet.
8. The method according to claim 7, comprising arranging the acoustic deflecting member to at least partially obscure or cover the inlet relative to the identified noise source.
9. The method according to claim 7 or claim 8, comprising arranging the acoustic deflecting member to project outwardly from the outer window in a direction away from the inner window.
10.The method according to any preceding claim, comprising arranging a first acoustic attenuation member in the cavity to extend laterally between the inner window and the inner window, the first acoustic attenuation member configured to restrict the sound transmission path.
11.The method according to any preceding claim, wherein selecting the position of the inlet and outlet comprises the step of positioning the outlet to be horizontally offset from the inlet.
12.The method according to any preceding claim, comprising arranging a second acoustic attenuation member in the cavity to extend substantially vertically, in use, between the outer window and the inner window to increase the length of the sound transmission path between the inlet and outlet.
13.A window assembly for installing into an opening of a building structure, the window assembly comprising: an outer window comprising an outboard frame defining a first outer opening, and a first outer fixed window portion and a first outer slideable window sash mounted in the first outer opening, the first outer slideable window sash being slideably mounted to the outboard frame to be openable, in use, to define an inlet; and an inner window comprising an inboard frame defining a first inner opening, and a first inner fixed window portion and a first inner slideable window sash mounted in the first inner opening, the first inner slideable window sash being slideably mounted to the inboard frame to be openable, in use, to define an outlet, wherein the outer window is spaced apart from the inner window to define a cavity therebetween, and wherein the window assembly comprises a first acoustic attenuation member connected to the inner window and the outer window and arranged in the cavity to extend laterally across the cavity to restrict a sound transmission path between the inlet and outlet.
14. The window assembly according to claim 13, wherein the first acoustic attenuation member is connected to and extends between the first outer fixed window portion and the first inner fixed window portion.
15.The window assembly according to claim 13 or claim 14, wherein the first acoustic attenuation member comprises an acoustic attenuating material configured and arranged to define an air flow duct therethrough.
16.The window assembly according to claim 15, wherein the air flow duct is stepped, substantially V-shaped, or substantially U-shaped.
17.The window assembly according to claim 15 or claim 16, wherein the first acoustic attenuation member comprises housing defining a housing inlet and a housing outlet aligned with upstream and downstream openings of the air flow duct.
18.The window assembly according to any one of claims 13 to 17, wherein the inlet and the outlet are vertically offset, in use.
19.The window assembly according to any one of claims 13 to 18, wherein, in use, one of the first outer slideable window sash and first inner slideable window sash is mounted such that it is positioned above the respective first outer fixed window portion or first inner fixed window portion, when in the closed position, and wherein, in use, the other of the first outer slideable window sash and first inner slideable window sash is mounted such that it is positioned below the respective first outer fixed window portion or first inner fixed window portion, when in the closed position.
20.The window assembly according to any one of claims 13 to 19, wherein the inlet and the outlet are horizontally offset, in use.
21.The window assembly according to any one of claims 13 to 20, comprising one or more further acoustic attenuation members arranged in the cavity to restrict the sound transmission path and/or to increase the length of the sound transmission path between the inlet and outlet.
22.The window assembly according to any one of claims 13 to 21, comprising an acoustic deflecting member configured and arranged to deflect sound waves travelling from an identified noise source away from the inlet.
23.The window assembly according to claim 22, wherein the acoustic deflecting member is configured and arranged to at least partially obscure or cover the inlet.
24.The window assembly according to claim 22 or claim 23, wherein the acoustic deflecting member is configured and arranged to project outwardly from the outer window in a direction away from the inner window.
25.The window assembly according to any one of claims 22 to 24, wherein the acoustic deflecting member is substantially L-shaped or curved.