In general, an operable window assembly includes a sash, frame, and one or more glass panels (e.g., monolithic glass or insulating units having two or more glass panels). The one or more glass panels are mounted within the sash adjacent the inner surface of the sash, and the sash is mounted within the frame adjacent the inner surface of the frame. The frame is then mounted into an opening of a building such that the outer surface of the frame is adjacent a wall of the building that defines the opening. The sash and frame may include hollow chambers extending longitudinally within the sash and the frame, and heat differentials between the exterior surfaces of the sash and frame and the interior surfaces of the sash and frame generate convection currents of air between the sash and frame and within the hollow chambers. These convection currents transfer heat from the warmer portions of the sash and frame to the cooler portions of the sash and frame, which can reduce the thermal efficiency of the window assembly. In addition, heat is transferred between the exterior of the sash and frame and the interior of the sash and frame through conduction and radiation. For example, heat is transferred via conduction between the one or more glass panels and the sash (or frame) and between the interior and exterior portions of the sash or frame and any thermal breaks joining these portions.
Therefore, there is a need in the art to provide a more thermally efficient window assembly.
Various embodiments of an operable window assembly include a frame, a sash, and at least one elongated frame insulating element that is formed separately from the frame. The frame has an inner surface, and the inner surface defines a track that extends outwardly from the inner surface. The track defines a retaining channel along a longitudinal axis of the track. The sash has an outer surface, and the sash is mounted within the frame such that the outer surface of the sash is disposed opposite to and cofaces the inner surface of the frame. The at least one elongated frame insulating element includes a frame engaging protrusion that extends outwardly from a first surface of the at least one elongated frame insulating element, and the frame engaging protrusion is slidably disposed within the retaining channel. In addition, the at least one elongated frame insulating element defines a plurality of chambers that extend substantially parallel to a longitudinal axis of the at least one elongated frame insulating element. The chambers reduce the size of the space between the frame and the sash, and reducing the size of the space reduces the size of the convection currents that may form between the frame and sash, which reduces the amount of heat transferred through convection. In addition, in one embodiment, the elongated frame insulating element is formed of a material having low thermal conductivity relative to the thermal conductivity(s) of the material(s) from which the frame and sash are formed, which reduces the heat transferred through conduction between the sash and the frame and portions of each.
In one embodiment, the outer surface of the sash defines a second track that extends outwardly from the outer surface of the sash, and the second track defines a second retaining channel along a longitudinal axis of the second track. The window assembly further includes at least one elongated sash insulating element formed separately from the sash. The elongated sash insulating element includes a sash engaging protrusion that extends outwardly from a first surface of the elongated sash insulating element, and the sash engaging protrusion is slidably disposed within the second retaining channel. The elongated sash insulating element also defines a plurality of chambers that extend substantially parallel to a longitudinal axis of the elongated sash insulating element.
Furthermore, the elongated frame insulating element includes a second surface that is spaced apart from and opposite its first surface, and the elongated sash insulating element includes a second surface that is spaced apart from and opposite its first surface. When the sash is disposed within the frame in a closed position, the second surface of the elongated sash insulating element and the second surface of the elongated frame insulating element are disposed adjacent to and substantially cofacing each other. In a particular embodiment, the second surfaces at least partially engage each other. The arrangement of the elongated sash insulating element and the elongated frame insulating element further reduces the size of the space between the sash and the frame, which reduces the size of convection currents that may form between the sash and the frame.
In a further embodiment, the frame defines at least one chamber between the interior surface and the exterior surface of the frame, and the sash defines at least one chamber between the interior surface and the exterior surface of the sash. An elongated foam member is disposed within the chamber of the frame, and another elongated foam member is disposed within the chamber of the sash. The elongated foam members further reduce the size of the space within the chamber in which convection currents can form, which increases the thermal efficiency of the window assembly.
Furthermore, in an embodiment in which the interior and exterior surfaces of the sash and frame are formed of aluminum or other materials having relatively high thermal conductivity, the thickness of the exterior surfaces may be decreased and the thickness of the interior surfaces may be increased, which causes the interior surfaces to act as a heat sink. In particular, the increased mass of the interior surfaces slows the rate of heat transferred through the interior surfaces, thus further increasing the thermal efficiency of the window assembly.
An alternative embodiment of the invention includes a fixed frame inoperable window assembly that includes a frame, at least one glass panel, a glass stop, and at least one elongated frame insulating element. The frame has an inner surface, and the inner surface has a first portion that defines a track extending outwardly from the inner surface. The track defines a retaining channel along a longitudinal axis of the track. The glass stop is disposed adjacent a second portion of the inner surface of the frame and the at least one glass panel, and the at least one glass panel is disposed adjacent a third portion of the inner surface of the frame. The first portion of the inner surface of the frame is disposed between the second portion and the third portion. The at least one elongated frame insulating element is formed separately from the frame and includes a frame engaging protrusion that extends outwardly from a first surface of the at least one elongated frame insulating element. The frame engaging protrusion is slidably disposed within the retaining channel. The at least one elongated frame insulating element defines a plurality of chambers that extend substantially parallel to a longitudinal axis of the at least one elongated frame insulating element, and a second surface of the at least one elongated frame insulating element that is opposite and spaced apart from the first surface of the at least one elongated frame insulating element is opposite and cofaces at least a portion of the glass stop.
In another embodiment of the invention, a window assembly comprises a frame having an interior portion and an exterior portion, and the interior portion includes an interior surface that faces an interior area of a building in which the window assembly is installed. The exterior portion includes an exterior surface that faces an exterior area of the building. The interior portion defines a chamber that extends therethrough along a longitudinal axis of the interior portion. The interior surface has a first thickness, and the exterior surface has a second thickness that is less than the first thickness. In a further embodiment, the frame also includes a thermal break portion that extends between the interior portion and the exterior portion, and the thermal break portion is formed of a material having a thermal conductivity that is less than the thermal conductivity of the material from which the frame is formed.
For example, in a particular embodiment, the thickness of the interior surface of the frame is about 35% greater than the thickness of the exterior surface of the frame. By increasing the thickness of the interior surface, the interior surface acts as a heat sink during cooler months—storing radiant heat received through the glass panel and any heat transferred to the interior surface through conduction or convection from the exterior surface. Because the convection currents in the interior area of the building can be significantly larger than the convection currents that may form in the chamber(s) between the interior surface and the exterior surface, less of the heat stored in the interior surface is released to the exterior area of the building. According to one embodiment, this arrangement increases the thermal performance of the window assembly during the cooler months.
Having thus described various embodiments of the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
Various embodiments of the invention are described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown in the figures. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.
Various embodiments and elements thereof are discussed below in detail.
The interior surface 22 of the frame 12 is part of an interior portion 23 of the frame 12, and the exterior surface 20 of the frame 12 is part of an exterior portion 25 of the frame 12. The interior portion 23 and the exterior portion 25 of the frame 12 are each formed from an extruded material, such as aluminum, steel, or other suitable material, and they are joined together via thermal breaks 21. The thermal breaks 21 are formed of a material having low thermal conductivity (e.g., glass fiber, nylon polyamide 6/6 with glass fiber, vinyl, acrylonitrile butadiene styrene (ABS), or rigid polyvinyl chloride (PVC)) relative to the thermal conductivity of the material used to form the frame 12 so as to reduce the heat transferred via conduction between the interior portion 23 and the exterior portion 20 of the frame 12. In addition, in one embodiment, the thermal breaks 21 are formed using an extrusion process. In various embodiments, the length of the thermal breaks between the exterior portion 25 and the interior portion 23 may be chosen based on the material of the frame 12, the material of the thermal break 21, the U-value (or range of U-values) desired for the window assembly 10, and/or the load intended for the frame 12. In a particular embodiment in which the frame 12 material is aluminum and the thermal break 21 material is polyamide 6/6 with glass fiber, the length of the thermal breaks 21 are about 38 mm.
According to one embodiment, the interior portion 23 and the exterior portion 25 of the frame 12 are hollow and each define chambers 27 that extend substantially parallel to the longitudinal axis of the frame 12. In addition, the adjacent surfaces of the thermal breaks 21, the interior portion 23, and the exterior portion 25 also define a chamber 27a between them. As shown in
As shown in
According to the embodiment shown in
In addition, according to various embodiments, the interior surface 22 of the frame 12 has a greater thickness than the exterior surface 20 of the frame 12. For example, in one embodiment, the thickness of the interior surface 22 of the frame 12 is about 35% greater than the thickness of the exterior surface 20 of the frame 12. By increasing the thickness of the interior surface 22, the interior surface 22 acts as a heat sink during cooler months—storing radiant heat received through the glass panel 16 and any heat transferred to the interior surface 22 through conduction or convection from the exterior surface 20. Because the convection currents in the interior area of the building can be significantly larger than the convection currents that may form in the chambers 27 between the interior surface 22 and the exterior surface 20, less of the heat stored in the interior surface 22 is released to the exterior area of the building. According to one embodiment, this arrangement increases the thermal performance of the window assembly 10 during the cooler months.
According to various embodiments, the glass panel 16 is mounted within the sash 14 adjacent its inner surface 30. In particular, the glass panel 16 is mounted adjacent an exterior portion 38 of the sash 14, and the edges of the glass panel 16 are secured within the sash 14 between an inner portion 24a of the exterior surface 24 of the sash 14 and a glass stop 40 that is mounted adjacent an interior portion 36 of the sash 14. In various embodiments, the glass panel 16 is an insulating unit that includes two or more glass panels. For example, in a particular embodiment, a conventional insulating unit may be used that includes two panes of ¼″ glass, a low e coating, and ½″ aluminum box spacer. In addition, in various embodiments, the insulating unit may include an inert gas or other insulating medium between the glass panels of the insulating unit to further increase the thermal efficiency of the window assembly.
In various embodiments, the interior portion 36 and the exterior portion 38 of the sash 14 are each formed from an extruded material, such as aluminum, steel, or other suitable metallic or non-metallic material, and they are joined together via thermal breaks 34. The thermal breaks 34 are formed of a material having low thermal conductivity (e.g., glass fiber, nylon polyamide 6/6 with glass fiber, vinyl, acrylonitrile butadiene styrene (ABS), or rigid polyvinyl chloride (PVC)) relative to the thermal conductivity of the material used to form the sash 14 so as to reduce heat transferred via conduction between the inside portion 36 and the outside portion 38 of the sash 14. In addition, in one embodiment, the thermal breaks 34 are elongated members and are formed using an extrusion process. In various embodiments, the length of the thermal breaks between the exterior portion 38 and the interior portion 36 may be chosen based on the material of the sash 14, the material of the thermal break 34, the U-value (or range of U-values) desired for the window assembly 10, and/or the load intended for the sash 14. In a particular embodiment in which the sash 14 material is aluminum and the thermal break 34 material is polyamide 6/6 with glass fiber, the length of the thermal breaks 34 are about 38 mm.
According to one embodiment, the interior portion 36 and the exterior portion 38 of the sash 14 are hollow and each define chambers 39 that extend substantially parallel to the longitudinal axis of the sash 14. In addition, the adjacent surfaces of the thermal breaks 34, the interior portion 36, and the exterior portion 38 also define a chamber 39a between them. As shown in
As shown in
In addition, as shown in
According to the embodiment shown in
In addition, according to one embodiment, the interior surface 26 of the sash 14 has a greater thickness than the exterior surface 24 of the sash 14. For example, according to one embodiment, the thickness of the interior surface 26 of the sash 14 is about 20% greater than the thickness of the exterior surface 24 of the sash 14. By increasing the thickness of the interior surface 26, the interior surface 26 acts as a heat sink during cooler months—storing radiant heat received through the glass panel 16 and any heat transferred to the interior surface 26 through conduction and convection from the exterior surface 24. Because the convection currents in the interior area of the building can be significantly larger than the convection currents that may form in the chambers 39 between the interior surface 26 and the exterior surface 24, less of the heat stored in the interior surface 26 is released to the exterior of the building. According to one embodiment, this arrangement increases the thermal performance of the window assembly 10 during the cooler months.
In addition, the embodiment of the sash 14 shown in
As noted above, the embodiment of the glass stop 40 shown in
The glass abutting portion 41 is disposed adjacent the glass panel 16 and prevents the glass panel 16 from moving toward the interior portion 36 of the sash 14. To prevent heat transfer through conduction between the glass panel 16 and the glass stop 40, an elongated glass insulating member 43 formed of a material having low thermal conductivity (e.g., silicone, EPDM rubber) relative to the thermal conductivities of the materials used to form the sash 14 or glass panel 16 may be disposed between the glass abutting portion 41 and the glass panel 16.
When mounted to the sash 14, at least a portion of the glass stop 40, an edge of the glass panel 16 disposed between the glass abutting portion 41 and the inner surface 30 of the sash 14, and at least a portion of the inner surface 30 of the sash 14 define a chamber 44 through which convection currents may form.
In one embodiment, the glass stop 40 may be elongated and formed from an extruded material, such as aluminum, steel, or other suitable material. In another embodiment (not shown), the window assembly 10 may include a plurality of glass stops 40 that are spaced apart from each other and disposed along the inner surface 30 of the sash 14.
As shown in
In one embodiment, the fourth surface 104 has a height that is greater than a height of the third surface 103, resulting in a cross sectional shape that is asymmetrical, wherein the cross section is taken through a plane that is substantially perpendicular to the longitudinal axis of the elongated frame insulating element 18, and the cross sectional shape is asymmetrical with respect to a plane extending substantially perpendicular to the first surface 101.
As shown in
According to a particular embodiment, the frame engaging protrusion 110 extends outwardly from the first surface 101 in a direction away from the second surface 102. The frame engaging protrusion 110 includes a head portion 110a at its distal end and a neck portion 110b extending between the head portion 110a and the first surface 101. A width of the head portion 110a is greater than a width of the retaining channel 17 but less than a width of the track 29, and the a width of the neck portion 110b is less than the width of the head portion 110a and the width of the retaining channel 17. This configuration allows the neck portion 110b to be slidably disposed within the retaining channel 17 and the head portion 110b to be secured within the track 29.
In addition, according to various embodiments, one or more ribs 112 extend outwardly from the second surface 102 in a direction away from the first surface 101, and the ribs 112 extend longitudinally along at least a portion of the second surface 102. In the embodiment shown in
As shown in
In one embodiment, the third surface 53 and the fourth surface 54 have substantially similar heights, resulting in a cross sectional shape that is substantially symmetrical, wherein the cross section is taken through a plane that is substantially perpendicular to the longitudinal axis of the elongated sash insulating element 50, and the cross sectional shape is symmetrical with respect to a plane extending substantially perpendicular to the first surface 51.
According to a particular embodiment, the sash engaging protrusion 55 extends outwardly from the first surface 51 in a direction away from the second surface 52. The sash engaging protrusion 55 includes a head portion 55a at its distal end and a neck portion 55b extending between the head portion 55a and the first surface 51. A width of the head portion 55a is greater than a width of the retaining channel 31 but less than a width of the track 35 and the a width of the neck portion 55b is less than the width of the head portion 55a and the width of the retaining channel 31. This configuration allows the neck portion 55b to be slidably disposed within the retaining channel 31 and the head portion 55b to be secured within the track 35.
According to the embodiment shown in
In addition, the elongated inner sash insulating element 60 is formed separately from the sash 14 from a material having low thermal conductivity relative to the thermal conductivity of the material used to form the sash 14. For example, in one embodiment, the elongated inner sash insulating element 60 is extruded EPDM rubber, and in another embodiment, the element 60 is extruded silicone. In various other embodiments, the elongated inner sash insulating element 60 may be formed of other low thermal conductivity materials, such as, for example, the same material used to form the thermal breaks 34a, 34b, glass fiber, nylon polyamide 6/6 with glass fiber, vinyl, ABS, or rigid PVC.
According to the embodiment shown in
In addition, the elongated foam members 70 are slidably disposed within the central chamber 27a of the frame 12 and the central chamber of the sash 39a. In the embodiment shown in
In addition, the frame engaging protrusion 110 of the elongated frame insulating element 18 is slidably disposed within the retaining channel 17 of the frame 12 such that the elongated frame insulating element 18 is disposed adjacent the inner surface 32 of the frame 12 and the finger portion 105 is disposed adjacent an interior portion 23 of the frame 12. In one embodiment, the elongated frame insulating element 18 is one piece and extends the entire perimeter of the inner surface 32. In various other embodiments, the elongated frame insulating element 18 includes two or more separate pieces (e.g., formed separately, or formed from the same extrusion process and then cut into separate pieces). In a particular embodiment, the pieces include a first piece, a second piece, a third piece, and a fourth piece. The first piece is disposed adjacent the inner surface 32 of the head member 12a, the second piece is disposed adjacent the inner surface 32 of the sill member 12b, the third piece is disposed adjacent the inner surface 32 of one of the jamb members 12c, and the fourth piece is disposed adjacent the inner surface 32 of the other jamb member 12c. In a further embodiment, one or more of the pieces include mitered or cut-out portions at one or both of their ends to allow the end of the piece to abut an adjacent piece more closely.
Similarly, an inner sash engaging protrusion 68 of the elongated inner sash insulating element 60 is slidably disposed within the retaining channel 37 of the sash 14 such that the elongated inner sash insulating element 60 is disposed adjacent the inner surface 30 of the sash 14 and a finger portion 69 of the elongated inner sash insulating element 60 is disposed adjacent the interior portion 36 of the sash 14. In one embodiment, the finger portion 69 engages a portion of the glass stop 40, preventing the flow of air past the finger portion 69. According to one embodiment, the use of the elongated inner sash insulating element 60 reduces the size of the convection currents that can form in the chamber 44 defined between the glass stop 40, the glass panel 16, and the inner surface 30 of the sash 14.
In addition, in one embodiment, the elongated inner sash insulating element 60 is one piece and extends the entire perimeter of the inner surface 30. In various other embodiments, the elongated inner sash insulating element 60 includes two or more separate pieces (e.g., formed separately, or formed from the same extrusion process and then cut into separate pieces). In a particular embodiment, the pieces include a first piece, a second piece, a third piece, and a fourth piece. The first piece is disposed adjacent the inner surface 30 of the top rail 14a, the second piece is disposed adjacent the inner surface 30 of the bottom rail 14b, the third piece is disposed adjacent the inner surface 30 of one of the stiles 14c, and the fourth piece is disposed adjacent the inner surface 30 of the other stile 14c. In one embodiment, one or more of the pieces may include mitered or cut-out portions at one or both of their ends to allow the end of the piece to abut an adjacent piece more closely.
Likewise, the sash engaging protrusion 55 of the elongated sash insulating element 50 is slidably disposed within the retaining channel 31 of the sash 14 such that the elongated sash insulating element 50 is disposed adjacent the outer surface 28 of the sash 14. In one embodiment, the elongated sash insulating element 50 is one piece and extends the entire perimeter of the outer surface 28. In various other embodiments, the elongated sash insulating element 50 includes two or more separate pieces (e.g., formed separately, or formed from the same extrusion process and then cut into separate pieces). In a particular embodiment, the pieces include a first piece, a second piece, a third piece, and a fourth piece. The first piece is disposed adjacent the outer surface 28 of the top rail 14a, the second piece is disposed adjacent the outer surface 28 of the bottom rail 14b, the third piece is disposed adjacent the outer surface 28 of one of the stiles 14c, and the fourth piece is disposed adjacent the outer surface 28 of the other stile 14c.
The above embodiments describe each of the elongated frame insulating element 18, the elongated sash insulating element 50, and the elongated inner sash insulating element 60 as having a male engaging portion (e.g., protrusions 110, 55, 68) that engages a female engaging portion (e.g., tracks 29, 33, 35) of the frame 12 or sash 14. However, in alternative embodiments (not shown), the elongated frame insulating element 18, the elongated sash insulating element 50, and/or the elongated inner sash insulating element 60 may include one or more female engaging portions that are each configured for slidably receiving a corresponding male engaging portion that extends from a surface of the frame 12 or sash 14. For example, as shown in
As noted above, the sash 14 shown in
Of course, various other embodiments may include slidably disposing an asymmetrically shaped insulating element on the outer surface 28 of the sash 14 and a symmetrically shaped insulating element on the inner surface 32 of the frame 12. Alternatively, various embodiments may include slidably disposing asymmetrically shaped insulating elements on both the outer surface 28 of the sash 14 and the inner surface 32 of the frame 12. And, in yet another embodiment, symmetrically shaped insulating elements may be slidably disposed on both the outer surface 28 of the sash 14 and the inner surface 32 of the frame 12.
In various embodiments, such as those described above in relation to
According to various embodiments, the thermal performance of a window assembly, such as the window assembly 10 described above in relation to
According to various embodiments, the elongated frame insulating element 88 shown in
Furthermore, window assemblies made from aluminum or other metals having relatively high thermal conductivity are prone to “sweating” in the cooler months due to condensation resulting from heat transferred through the window assembly. According to various embodiments, reducing the amount of heat transferred through the window assembly results in an improved condensation resistance factor (CRF) for the window assembly. For example, window assemblies like the embodiments described above in relation to
Although this invention has been described in specific detail with reference to the disclosed embodiments, it will be understood that many variations and modifications may be effected within the spirit and scope of the invention as described in the appended claims.