Patent Application
20140157696
The present invention relates to the insulation and air sealing of primary windows using an interior insulating glass assembly.
A substantial portion of costs associated with the maintenance of commercial and residential buildings is attributable to energy consumption, including heating and cooling. Windows are the single largest point source of energy loss in a building envelope. Many U.S. buildings do not possess energy efficient windows that meet current standards and, generally, the only practical means to address these energy losses was to replace the existing windows with modern replacement windows such as 2 or 3-pane systems that can reduce energy losses through the window units. Commercially available “high performance” replacement windows, if installed correctly, can deliver substantial improvements in energy savings if replacing either a single pane or double pane window.
However, full window replacement is costly due to the high cost of the new window, installation and disposal fees, site preparation and finishing, and possible remediation (all buildings constructed before 1978 pose the risk of exposing occupants to lead contamination when the building envelope is disrupted). Hence, due to these high costs, full window replacement is rarely, if ever, economically justified solely on the basis of energy savings or consequent improvements in occupant comfort. For this reason, traditional weatherization efforts, despite recognizing the energy loss associated with a building's windows, have elected not to address window energy losses beyond minimal caulking and weatherstripping, despite their substantially adverse impact on building operating costs, occupant comfort, and environmental considerations.
Weatherization programs that measure before and after energy consumption have historically shown a rather consistent pattern where 10-30 percent of the homes which are weatherized show no improvement in energy consumption, and in some cases, an increase in energy consumption after being weatherized. While the specific causes of this phenomena are not fully understood, it does account for a decrease in the overall cost effectiveness of building weatherization. There is some empirical evidence suggesting that windows, which are known to be a source of occupant discomfort due to mean radiant temperature effects and natural convection drafts, if not properly addressed as an element of a weatherization project, may be the cause of the problem as each of these window-related consequences would cause a home owner to adjust the interior room temperature (calling for increased heat) seeking to offset the discomfort associated with poor window performance.
For at least these reasons, there remains a need for improved window systems that can reduce energy consumption and enhance occupant comfort in commercial and residential buildings.
In accordance with one embodiment of the present invention, there is provided an insulating panel assembly for sealing a window within a jamb having an interior side and an exterior side. As used herein, “jamb” means the sill or framing around a primary window. The insulating panel assembly comprises a frame for a glazing panel that minimizes conductive and radiant energy losses. The frame is configured to fit within the jamb, and the frame has an external perimeter, an internal perimeter, and at least one frame portion defining at least one cavity extending along its length. The cavity is located between the internal perimeter of the frame and the external perimeter of the frame and is enclosed to prevent the passage of air between the external perimeter of the frame and the internal perimeter of the frame. In an installed condition, the frame reduces airflow in the exterior and interior direction around the frame.
In accordance with another embodiment of the present invention, there is provided an insulating panel assembly that comprises a frame for a glazing panel that minimizes conductive and radiant energy losses. The frame has an external perimeter surface, an exterior surface facing the interior side of the window, and an interior surface in opposing relationship to the exterior surface. The assembly further comprises at least one of a blind stop configured to directly or indirectly contact the exterior surface of the frame and a trim stop configured to directly or indirectly contact the interior surface of the frame and a compressible seal extending outwardly from the external perimeter surface of the frame. In an installed condition, the blind stop is coupled to the jamb between the frame and the window and the exterior surface of the frame directly or indirectly contacts the blind stop, or the trim stop is coupled to the jamb such that the frame is between the trim stop and the window and the interior surface of the frame directly or indirectly contacts the trim stop. The frame bears the compressible seal against the jamb on the interior side of the window forming a first barrier impeding the flow of air between the exterior surface and the interior surface of the frame, and the blind stop or the trim stop forms a second barrier impeding the flow of air between the exterior surface and the interior surface of the frame resulting in reduced air flow in the interior and exterior direction. The first and second barriers together define an insulating chamber with the external perimeter surface of the frame and the jamb.
In accordance with another embodiment of the present invention, there is provided a mounting assembly for sealing a window within a jamb having an interior side and an exterior side. The mounting assembly comprises a frame for a glazing panel that minimizes conductive and radiant energy losses. The frame has an external perimeter surface, an exterior surface facing the interior side of the window, and an interior surface in opposing relationship to the exterior surface, the external perimeter surface being free of apertures for mounting the frame to the jamb. The mounting assembly further comprises a compressible seal extending outwardly from the external perimeter surface of the frame and a bracket having a mounting portion and at least one of a front portion configured to engage the interior surface of the frame and a rear portion configured to engage the exterior surface of the frame. In an installed condition, the frame bears the compressible seal against the jamb on the interior side of the window and the compressible seal impedes the transmission of air between the exterior surface and the interior surface of the frame. The mounting portion of the bracket is fastened to the jamb and the front portion or rear portion of the bracket limits movement of the frame within the jamb.
In accordance with yet another embodiment of the present invention, there is provided a method of installing a mounting assembly within a jamb for sealing a window having an interior side and an exterior side. The method comprises attaching a bracket to the jamb, the bracket having a mounting portion and at least one of a front portion configured to engage the interior surface of the frame and a rear portion configured to engage the exterior surface of the frame; inserting a frame within the jamb and adjacent to the bracket such that the frame bears a compressible seal against the jamb and the compressible seal impedes the flow of air between the exterior surface and the interior surface of the frame; and engaging the front portion of the bracket with an interior surface of the frame or the rear portion of the bracket with an exterior surface of the frame to limit movement of the frame within the jamb, thus eliminating the need for apertures in the frame for mounting the frame to the jamb.
In accordance with yet another embodiment of the present invention, there is provided an airflow reduction system for sealing a window within a jamb having an interior side and an exterior side. The airflow reduction system comprises a frame for a glazing panel that minimizes conductive and radiant energy losses. The frame has an external perimeter surface and a compressible seal extending from at least a portion of the external perimeter surface of the frame. In an installed condition, the frame bears the compressible seal against the jamb on the interior side of the window, and the airflow reduction system provides a first air infiltration and exfiltration rate between the exterior surface and the interior surface of the frame that is less than a second air infiltration and exfiltration rate between the exterior surface and the interior surface of the window.
In accordance with an alternative embodiment of the airflow reduction system, the assembly comprises a frame for a glazing panel that minimizes conductive and radiant energy losses and at least one of a blind stop and a trim stop. In an installed condition, the blind stop is attached to the jamb between the frame and the window, and a rear barrier is formed between the blind stop and the frame to impede the flow of air between the exterior surface and the interior surface of the frame; or the trim stop is attached to the jamb such that the frame is between the trim stop and the window, and a front barrier is formed between the trim stop and the frame to impede the flow of air between the exterior surface and the interior surface of the frame.
Other aspects and advantages of the invention will be apparent from the following detailed description wherein reference is made to the accompanying drawings. In order that the invention may be more fully understood, the following figures are provided by way of illustration, in which:
a is front view of an insulating panel assembly in an installed condition according to another embodiment of the present invention;
b is a perspective view of a corner of the insulating panel assembly illustrated in
a is front view of an insulating panel assembly according to yet another embodiment of the present invention;
b is a cross-sectional view of the insulating panel assembly illustrated in
c is a plan view of one embodiment of the fastening means illustrated in
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.
In developing improved systems for reducing the energy consumption in commercial and residential buildings that is attributable to their windows, it has been discovered that the installation of secondary panes of glass or plastic on existing windows or the installation of replacement windows to improve the energy performance may suffer from certain shortcomings either in performance, feasibility of on-site implementation, and/or the cost of the retrofit in comparison to the benefit.
For example, the application of films to existing prime windows to improve the energy performance of the prime window, while effective at managing solar heat gain, do not themselves provide the enhanced insulating performance or reduced airflow that is delivered by replacement windows. Equally important, the application of a film to a prime window typically voids the existing window's seal warranty.
Additionally, storm windows constructed with low-e glass can, subject to the design of the particular unit, deliver substantially equivalent energy savings to that delivered by high performance replacement windows by virtue of the fact that the combination of properly designed low-e glass storm windows and existing prime windows together can achieve comparable thermal properties, e.g. U-factor, SHGC, to that delivered by a state-of-the-art replacement window. In most cases, however, storm windows are not aesthetically attractive, have ineffective sealing mechanisms, and possess a limited ability to manage air flow.
Referring generally to the figures, an insulating panel assembly (101) is provided for sealing a window within a jamb (102) having an interior side (107) and an exterior side (106). The insulating panel assembly comprises a frame (100) configured to fit within the jamb (102), and the frame has an external perimeter (104), an internal perimeter (105a, 105b), and at least one frame portion (600a, 600b, 600c, 600d) defining at least one cavity (108) extending along its length. The cavity is located between the internal perimeter of the frame and the external perimeter of the frame and is enclosed to prevent the passage of air from the external perimeter of the frame to the internal perimeter of the frame. Although depicted with a square cross-section, the frame portion may have any cross-section. For example, the frame portion may have a generally U-shaped cross-section to provide a channel which receives the glazing panel. In such an embodiment, the cavity is formed after the glazing panel is installed in the frame.
In another embodiment of the invention, the insulating panel assembly includes a frame having an external perimeter surface, an exterior surface facing the interior side of the window, and an interior surface in opposing relationship to the exterior surface; at least one of a blind stop configured to directly or indirectly contact the exterior surface of the frame and a trim stop configured to directly or indirectly contact the interior surface of the frame; and a compressible seal extending outwardly from the external perimeter surface of the frame. In an installed condition, the blind stop is coupled to the jamb between the frame and the window and the exterior surface of the frame directly or indirectly contacts the blind stop, or the trim stop is coupled to the jamb such that the frame is between the trim stop and the window and the interior surface of the frame directly or indirectly contacts the trim stop. The frame bears the compressible seal against the jamb on the interior side of the window forming a first barrier impeding the flow of air between the exterior surface and the interior surface of the frame, and the blind stop or the trim stop forms a second barrier impeding the flow of air between the exterior surface and the interior surface of the frame. The first and second barriers together define an air sealing chamber with the external perimeter surface of the frame and the jamb.
A mounting assembly for sealing a window within a jamb having an interior side and an exterior side is also provided. The mounting assembly comprises a frame having an external perimeter surface, an exterior surface facing the interior side of the window, and an interior surface in opposing relationship to the exterior surface, the external perimeter surface being free of apertures for mounting the frame to the jamb; a compressible seal extending outwardly from the external perimeter surface of the frame; and a bracket having a mounting portion and at least one of a front portion configured to engage the interior surface of the frame and a rear portion configured to engage the exterior surface of the frame. In an installed condition, the frame bears the compressible seal against the jamb on the interior side of the window and the compressible seal impedes the transmission of air between the exterior surface and the interior surface of the frame. The mounting portion of the bracket is fastened to the jamb and the front portion or rear portion of the bracket limits movement of the frame within the jamb.
A method is provided for installing a mounting assembly within a jamb for sealing a window having an interior side and an exterior side. The method comprises attaching a bracket to the jamb, the bracket having a mounting portion and at least one of a front portion configured to engage the interior surface of the frame and a rear portion configured to engage the exterior surface of the frame; inserting a frame within the jamb and adjacent to the bracket such that the frame bears a compressible seal against the jamb and the compressible seal impedes the flow of air between the exterior surface and the interior surface of the frame; and engaging the front portion of the bracket with an interior surface of the frame or the rear portion of the bracket with an exterior surface of the frame to limit movement of the frame within the jamb, thus eliminating the need for apertures in the frame for mounting the frame to the jamb.
Also provided is an airflow reduction system for sealing a window within a jamb having an interior side and an exterior side. It includes a frame having an external perimeter surface and a compressible seal extending from at least a portion of the external perimeter surface of the frame. In an installed condition, the frame bears the compressible seal against the jamb on the interior side of the window, and the airflow reduction system provides a first air infiltration and exfiltration rate between the exterior surface and the interior surface of the frame that is less than a second air infiltration and exfiltration rate between the exterior surface and the interior surface of the window.
Air infiltration rates can be measured using methods known by those with skill in the art. A standard method used for various fenestration products to measure air infiltration at elevated static test pressures is prescribed by ASTM E 283, which is used to determine air infiltration independent of the prime window to which the unit would be installed and is reported in cfm/ft2 of glass area. An alternative method in use is a modified blower door test which measures the Effective Leakage Area (ELA) of an existing window and the degree of improvement that can be attained by performance enhancement measures such as installation of an airflow reduction system. In this method, the room is either depressurized or pressurized via a blower door apparatus, the window to be tested is isolated, and the air flow is measured passing from the exterior through the existing window into the room, or vice versa. This methodology allows for before and after treatment data. The ELA, which is reported in square inches, can be correlated to infiltration by comparing pressure differentials that typically exist between the exterior and interior of the building.
Referring now specifically to
The panels (13a, 13b) within the frame (10) may include one or more coatings on the interior and/or exterior surface of at least one of the panels. Low emissivity or low-e coatings are used to improve energy efficiency by reducing radiant heat loss through the window. An advantage of the present invention is that when sunlight passes through the primary window (14), the coatings on the panel assist with trapping the energy and heat the pocket of air (15) such that the temperature and pressure of the enclosed pocket of air (15) is slightly greater than either the exterior or interior of the structure in which the primary window (14) is installed. Different coatings (and also different tinted glasses, laminate interlayers, or films either alone or in combination) will exhibit this effect to a greater or lesser degree depending upon the properties such as solar absorption, solar reflection, and emissivity. The increased pressure inhibits air infiltration from the interior and exterior of the structure and will promote the purging or expulsion of air, primarily through the primary window to the exterior which should have a poorer seal than the insulating panel assembly, thereby improving the efficiency of the window by reducing the transmission of air in the interior direction or exterior direction across the insulating panel assembly. At sun down, the glass panel no longer absorbs solar energy and is allowed to cool, thereby cooling the enclosed pocket of air resulting in equalization with the exterior side of the primary window.
The cycling of daylight and night time creates a pressurization cycle and the coating on the panel increases the amplitude of the temperature fluctuations to provide a purging or refreshing of the air within the enclosed pocket between the primary window and the frame, but with the purging predominantly to the exterior through the poorer seal of the window and minimal airflow across the insulating panel assembly to or from the interior of the building. The flow of air in and out of the enclosed pocket prevents the accumulation of moisture and eliminates the need to achieve a hermetic seal around the frame and the primary window.
More specifically, during the daytime in the summer season, when the window and insulating panel assembly are exposed to the sun (primarily direct solar exposure, but also indirect solar exposure), increasing pressure in the pocket of air creates back pressure to prevent hot, humid outside air from entering through existing primary window and causes some air within the pocket to exit to outside. At nighttime during the summer season, reduced pressure within the air pocket results from decreasing outdoor temperatures, enabling the pocket to receive fresh air to equilibrate. However, outside air temperatures typically decrease faster than the air pocket's temperature, so the pocket pressure remains slightly higher to neutral as compared to the pressure outside. Under solar exposure during the daytime in the winter season, the air pocket's pressure again increases, preventing cold outside air from entering through the existing primary window and causes some air within the pocket to exit to the outside. At nighttime during the winter season, similar to the summer season, the air pocket's pressure decreases as a result of either decreasing outdoor temperature or near constant outdoor temperature and no heat generation in the air pocket, enabling the air pocket to receive fresh air to equilibrate. The entry of cold, dry winter air does not create a moisture or condensation problem because of its low humidity content. The system is designed to allow for minimal air exchange which occurs predominantly between the pocket and the outside, and to a much lesser degree through the insulating panel assembly to or from the inside of the building. As previously discussed, the coatings on the panels (or also tinted glasses, laminate interlayers, or films either alone or in combination) magnify the amplitude of temperature fluctuations in the air pocket by absorbing radiation in the solar spectrum during the daytime such that the pressure differential between the air pocket and the outside causes a periodic change of atmosphere within the pocket, thereby reducing the likelihood of accumulated moisture in the pocket or condensation as a result thereof.
In addition to a compressible seal (11) extending from at least a portion of the external perimeter surface of the frame (10), the insulating panel assembly may also include at least one of a blind stop (20) and a trim stop (22). In an installed condition, the frame (10) may bear the compressible seal (11) against the jamb (12) on the interior side of the primary window (14). Alternatively, the blind stop (20) may be attached to the jamb (12) between the frame (10) and the primary window (14) to form a rear barrier between the blind stop (20) and the frame (10) to impede the flow of air (17, 19) between the exterior surface and the interior surface of the frame (10); or the trim stop (22) may be attached to the jamb (12) such that the frame (10) is between the trim stop (22) and the primary window (14), and a front barrier is formed between the trim stop (22) and the frame (10) to impede the flow of air (17, 19) between the exterior surface and the interior surface of the frame (10).
For any of the embodiments described, the airflow reduction system provides a substantially reduced infiltration and exfiltration rate after installation. Preferably upon installation, the air infiltration and exfiltration rate across the overall system is controlled in such a way as to reduce energy loss while also accommodating and benefitting from changes in pressure in the space between the original window and the air infiltration reduction system as described herein.
Although the possibility of optionally creating a hermetic seal is contemplated according to this invention, it has been discovered that a limited air infiltration is surprisingly beneficial. Despite the fact that a hermetic seal may seem intuitively superior, limited air infiltration has been discovered to confer at least the following benefits. First, even with limited air infiltration, energy losses are substantially reduced as compared to those associated with the original window. Second, limited air infiltration cooperates with temperature and pressure fluctuations of the air in the space between the frame of the system and the original window; specifically, the temperature and pressure fluctuations tend to dampen the air infiltration. Also, limited air infiltration helps encourage recycling of the air in the space between the frame of the system and the original window in such a way that reduces the accumulation of moisture.
In
The frame (100) includes an external perimeter (104) from which a compressible seal (109) extends, an internal perimeter (105a), and one or more frame portions. While the embodiment illustrated in
Referring again to
The frame of the insulating glass assembly may include either a single non-operable track in which a panel is installed, as illustrated in the embodiment in
In the embodiment illustrated in
A durable solar control coating or film or a low-emissivity coating, is preferably applied to at least one of the interior and exterior surface of the first and/or second panel.
The properties of the coating or film or tinted glass or interlayer are selected to increase the amplitude of day/night temperature fluctuations in the space between the insulating panel assembly and the primary window such that pressure differentials between the interior and exterior sides of the frame are cyclically increased to facilitate air flow into and out from the space between the airflow reduction system and the primary window, predominantly through the poorer seal of the primary window to the exterior.
The coating or film is also selected such that it will transmit the maximum amount of visible light with a reduced emissivity as compared to an uncoated panel. In a preferred embodiment of the present invention, the coating has an emittance of less than 0.16 which provides a reduction in the transmission of long-wave radiation, known as the Far Infrared (IR), thereby achieving an IR reflection efficiency of 84%. This reduced infrared emittance (or low emissivity) compared to an uncoated panel will reduce radiant heat loss across the window and insulating panel assembly.
Additional optional coatings may be applied, such as a coating that can absorb solar infrared radiation (wavelengths in the range of 0.30 to 2.5 microns), or a coating that can absorb solar infrared and UV radiation to cause an elevation of the surface temperature of the panel to which the coating is applied. The low-emissivity coating or solar control coating or film may also be combined with tinted glass, film, or plastic layers to further increase the temperature of the panel and absorb radiation in the solar spectrum. Not only will this solar absorption enhance the day/night temperature fluctuations in the space between the insulating panel assembly and the window, but the solar absorption can be tailored for the local climate to reduce solar heat gain into the building to reduce cooling demand.
Furthermore, the insulating panel assembly may also include a compressible seal. For example, in the embodiment illustrated in
The compressible seal is preferably made of a durable elastomeric material, preferably an ethylene-vinyl acetate copolymer, and is fabricated to allow for a pre-determined tolerance, such that the shape of the frame need not match the shape of the jamb exactly while still being capable of forming the first barrier. Furthermore, the seal allows for reasonable contraction and expansion over time without compromising the integrity of the seal. Equally important, the flexible nature of the seal will act to maintain seal integrity independent of changing ambient temperatures and conditions and the different rates of expansion and contraction with variable building materials used in the existing window jam and insulating panel assembly.
More specifically, the compressibility of the seal imparts to the insulating panel assembly the ability to fit within jambs that are not the same size as the frame or are not perfectly square by providing for forgiveness in the tolerances of the frame and imperfections in the existing jamb without having to fix or replace the existing jamb as part of on-site installation. The seal thereby provides the advantage of simplifying installation making it easier and faster to install multiple assemblies in a commercial or residential structure.
The insulating panel assembly may further comprise at least one of a blind stop (220) and a trim stop (230), as illustrated in
In an installed condition, the blind stop or the trim stop may form a second barrier impeding the flow of air between the exterior surface and the interior surface of the frame. Therefore, the first and second barriers together may define an air sealing chamber with the external perimeter surface of the frame and the jamb. Because the insulating panel assembly is intended for installation in a window jamb without removal of the primary window, it is preferred that the frame have a low profile to ensure sufficient window jamb depth is available on the interior side of the primary window for installation of the frame, blind stop, and trim stop. It may also be desirable to provide a frame having as small a frame width as possible to maximize the ratio of panel to frame for the insulating panel assembly.
According to another embodiment of the present invention, a mounting assembly is provided for sealing a window within a window jamb. The mounting assembly comprises a frame that has an external perimeter surface free of apertures for mounting the frame to the jamb, an exterior surface facing the interior side of the window, and an interior surface in opposing relationship to the exterior surface; and a compressible seal extending outwardly from the external perimeter surface of the frame. The mounting assembly may also include a bracket. The bracket may be made of a polymer or metal composition. Preferably, the bracket is metal and designed such that it can be easily manufactured using a stamping process.
In one embodiment of the present invention illustrated in
In an alternative embodiment of the present invention, the mounting bracket may also include a rear portion configured to engage the exterior surface of the frame. For example, as illustrated in
In both of the embodiments illustrated in
A method of installing a mounting assembly for sealing a window made according to the present invention may comprise attaching a bracket to the jamb, the bracket having a mounting portion and at least one of a front portion configured to engage the interior surface of the frame and a rear portion configured to engage the exterior surface of the frame. If the mounting portion does not include a rear portion, a blind stop should also be attached to the jamb adjacent to the rear portion of the bracket. Optionally, an insulating material may be applied between the jamb and the bracket to provide a thermal break. The insulating material is preferably a self-adhesive polyisobutylene tape.
The method may further comprise inserting a frame within the jamb and adjacent to the bracket such that the frame bears a compressible seal against the jamb and the compressible seal impedes the flow of air between the exterior surface and the interior surface of the frame. In the event any gaps exist between the compressible seal and the existing jamb due to excessive warping of the jamb, a caulk rope may be applied to the area to enhance the intended function of the elastomeric seal.
Finally, the method may comprise engaging the front portion of the bracket with an interior surface of the frame or the rear portion of the bracket with an exterior surface of the frame to limit movement of the frame within the jamb, thus eliminating the need for apertures in the frame for mounting the frame to the jamb. The engaging step may include deforming the front portion of the bracket into contact with the interior surface of the frame. Preferably, the bracket is designed such that the front portion may be easily adjusted using a tool, such as a screwdriver.
Optionally, a trim stop may also be attached to the jamb to contact the interior surface of the frame. Upon attaching at least one of a blind stop and a trim stop, a barrier may be formed between the frame and at least one of the blind stop and the trim stop to impede the flow of air between the exterior surface and the interior surface of the frame.
While preferred embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the spirit of the invention. Accordingly, it is intended that the appended claims cover all such variations as falling within the spirit and scope of the invention.
