Patent Application
20250075494
This invention relates to an attic baffle radiant barrier for installation to rafter studs or trusses.
Radiant barrier sheathing, typically used for roof deck and attic wall sheathing, has become a de facto standard in high solar radiation environments. Radiant barriers are installed in homes and structures, usually facing an attic space, primarily to reduce summer heat gain and reduce cooling costs. The barriers consist of a very low emissivity material that significantly limits the amount of heat that radiates from its surface. Radiant heat travels in a straight line away from any surface and heats anything solid that absorbs its energy. Most common insulation materials address conductive and convective heat flow, not radiant heat flow. In contrast, a radiant barrier reduces the radiant heat transfer from the underside of the heated roofing materials to other surfaces in the attic, thereby reducing the cooling load of the house.
Prior art radiant barriers comprise a wood-based sheathing panel or substrate with a highly reflective material adhered to the panel face facing the attic space. A layer of aluminum (typically aluminum foil) is commonly used as the reflective material, as it is, with a low emissivity of typically 0.05 or less, efficient at not transmitting radiant energy into the attic environment. Copper has an emissivity of as low as 0.02, but has a substantially higher cost and is not cost effective. In addition, both copper and aluminum tarnish or corrode over time (i.e., aged), increasing emissivity and reducing their effectiveness as a radiant barrier. Therefore, most radiant barriers will include a thin anti-oxidation coating layer to limit this effect.
The aluminum foil used in radiant barriers must be very pure to achieve a low emittance surface. The thickness of the aluminum does not affect performance; the aluminum only needs to cover the surface of the sheathing material. Typically, very thin foils (approximately 0.00025 inches thick) are used. As this foil is too thin (and thus too fragile) to be applied to wood structural panels directly, at present it is attached to another substrate, most often Kraft paper, for support. The process of attaching the thin foil to the paper is performed at a separate conversion facility, which purchases foil and paper and then bonds the two together. The combined overlay is then sold to wood structural panel producers for lamination to one side of a wood structural panel face to make the radiant barrier sheathing.
Radiant barrier sheathing panels are usually of large size (typically 4 ft. by 8 ft.), fairly heavy, and installed during construction.
In various exemplary embodiments, the present invention comprises an attic baffle radiant barrier for use in unvented attics and vented attics. The attic baffle comprises a baffle substrate with an elongated H-shape, with a cross-span extending between two legs on the left and right, each leg comprising an upper portion and a lower portion. A tab or extension extends from the respective ends of one or both portions of one or both legs of the “H”. The tabs or extensions may be used for stapling (i.e., using staples) or otherwise fastening the attic baffle radiant barrier to the bottoms, tops, or sides of rafter studs or trusses or similar frame members when installed.
A radiant barrier layer is affixed or adhered to one side of the baffle substrate. It may be affixed or adhered to the underside or to the top side. In some embodiments, a radiant barrier layer may be applied to both sides of the baffle substrate.
In a vented attic, the present invention can be affixed under the roof-decking during construction or retrofit on a pre-existing roof structure. In these installations, the radiant barrier layer side of the present invention typically faces down into the open attic space to create the radiant barrier system in the attic space.
In an unvented attic, spray insulation typically is applied on the roofing structure to create the conditioned space in the attic. In these installations, the radiant barrier layer side may be positioned upward, creating a radiant barrier channel between the attic baffle radiant barrier and the attic ceiling or roof deck.
In various exemplary embodiments, the present invention comprises an attic baffle radiant barrier 2 for use in unvented attics and vented attics. As seen in
The tabs or extensions 30 may be used for stapling (i.e., using staples 60) or otherwise fastening the attic baffle radiant barrier to the bottoms, tops, or sides of rafter studs or trusses 50 or similar frame members when installed. Staples or other fasteners 60 are inserted so may be used to secure the upper portion of the baffle to the rafter studs or trusses 50 or similar frame members, as seen in
A radiant barrier layer 20 is affixed or adhered to one side of the baffle substrate. It may be affixed or adhered to the underside (i.e., to the lower/inner faces of the cross-span and adjacent faces of the lower portions of the legs facing the attic space), or to the top side (i.e., to the upper/outer face of the cross-span and adjacent faces of the upper portions of the legs facing the roof deck and exterior). In some embodiments, a radiant barrier layer may be applied to both sides (as described above) of the baffle substrate.
The radiant barrier layer 20 comprises a metallic (typically aluminum or copper) layer, and can comprise a laminated radiant barrier sheet or foil (backed or unbacked) affixed to the substrate, or a sprayed-on or brushed-on metallic (generally aluminum or copper) layer on the corresponding surface of the substrate. The radiant barrier layer has a low emissivity (i.e., it is efficient at not transmitting radiant energy into an adjacent open space, such as an attic space). In one exemplary embodiment, such as where aluminum is used, the radiant barrier layer has a low emissivity of 0.05 or less. In another exemplary embodiment, such as where copper is used, has an emissivity of as low as 0.02.
The baffle substrate 10 may be made of corrugated paperboard, plastic, or similar material. The substrate may be creased or perforated along the long edges or joints so as to allow folding or flexing of the legs with respect to the cross-span, or of the tabs or extensions with respect to the legs, to provide flexibility and ease in installation. Likewise, the radiant barrier layer is similarly flexible to fold or flex with the substrate at these joints.
In several exemplary embodiments, the tabs or extensions are constructed or biased along the respective joint with the lower portion of the legs so as to extend back towards the cross-span at an acute angle, as seen in
In a vented attic (i.e., where air circulates between the interior attic space and the exterior of the structure to help reduce moisture accumulation and condensation), insulation typically is applied to the attic floor, so there is no conditioned space in the attic. The present invention can be affixed under the roof-decking during construction or retrofit on a pre-existing roof structure (e.g., where no radiant barrier sheathing or system was installed previously, or where a previous radiant barrier system has been damaged or degraded and needs replacement or removal). In these installations, the radiant barrier layer 20 side of the present invention typically faces down into the open attic space to create the radiant barrier system in the attic space.
In an unvented attic, an air-impermeable insulation or similar material is installed to the underside of the roof deck (i.e., the attic ceiling) to prevent airborne moisture from reaching a surface on which it can condensate inside the building envelope. Typically, spray insulation is applied on the roofing structure to create the conditioned space in the attic. In these installations, the radiant barrier layer 20 side may be positioned upward, creating a radiant barrier channel between the attic baffle radiant barrier and the attic ceiling or roof deck.
The present invention solves a problem with the reduced use of radiant barrier sheathing in certain attic types found in different climate zones. The International Code Council periodically updates the building codes in the International Energy Conservation Code (IECC), which is the model energy code in the U.S. and a number of other countries. The 2021 IEEC (and later updates) includes the designation of “Climate Zones.” Climate zones are defined at the county level in the U.S., and are based on various weather factors such as winter/summer temperature ranges, along with rainfall and humidity. The climate zone for an area dictates many of the energy-efficiency measures that must be included in building construction, particularly those relevant to the building envelope. With climate changes, the climate zones for an area can change or shift over time, so that new construction in an area may have different code requirements than past construction. Older structures thus may need updating or retrofitting to be protected from the change in ambient conditions in the area.
Prior art radiant barrier sheathing is limited to climate zones 1-4 due to potential condensation on the surface. In addition, the growing use of spray-applied polyurethane foam (SPF) insulation in residential unvented attics and crawl spaces is reducing the use of radiant barrier sheathing since SPF insulation is not allowed to be sprayed on the radiant barrier panel. The present invention provides a hybrid system that allows for proper use of a radiant barrier with ventilation and SPF insulation to allow for an unvented attic. This increases the potential number of climate zones for implementation of a “cool roof” system to reduce ice damming. More specifically, the present invention can be retrofit in buildings in climate zones 1-4. During a retrofit, the baffle is installed mechanically or chemically, and may be used with the radiant barrier side arranged towards the attic space where it can function properly.
Further, with new roof construction, inspections are often required. The present invention has the ability to hang from one end during installation so as not to interfere with inspection of the roof. The installer fastens the baffle on one side, allowing the other side of the baffle to hang until the insulator is ready to install installation. After installing insulation, the other flap or end is attached by the insulator or other installer.
Thus, it should be understood that the embodiments and examples described herein have been chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited for particular uses contemplated. Even though specific embodiments of this invention have been described, they are not to be taken as exhaustive. There are several variations that will be apparent to those skilled in the art.
This application claims benefit of and priority to U.S. Provisional App. No. 63/535,103, filed Aug. 29, 2023, which is incorporated herein by specific reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63535103 | Aug 2023 | US |
