Reflective insulation and radiant barrier

Abstract

The present invention relates to a reflective insulation and radiant barrier intended for use in creating more than one insulating air space in wall cavities formed by parallel structural members attached to the inside of building walls. Specifically, a reflective sheet that is folded to form an insulating panel for positioning between the structural members generally parallel to the building wall, a pair of creases for spreading along the inside surface of the structural members generally normal to the insulating panel, and a pair of tabs for attaching the reflective insulation to the face of the structural members generally parallel to the insulating panel is disclosed. Accordingly, the length of the pair of creases is such that the insulating panel generally bisects the cavity formed by the structural members to create two dead air spaces.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority of U.S. provisional application No. 60/443,399, filed Jan. 29, 2003, and U.S. provisional application No. 60/452,471, filed Mar. 6, 2003, which are relied on and incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to thermal insulation barriers used in building construction. More specifically, the present invention relates to a reflective insulation and radiant barrier intended for use in creating more than one insulating/reflective air space in wall cavities formed by parallel structural members attached to the inside of building walls.

BACKGROUND OF THE INVENTION

[0003] It is well known in the art that, when installed correctly, the use of insulation helps to maintain a comfortable temperature inside a building by reducing the heat transfer out of the building during the winter and reducing the heat transfer into the building during the summer. Because the amount of heat lost in the winter and gained in the summer is reduced, insulation lowers the costs associated with heating and cooling the building.

[0004] Heat transfer occurs through wall cavities from warmer areas to cooler areas by a combination of radiation, conduction, and convection. Heat flows by conduction from a hotter material to a colder material when the two materials touch. Heat transfer by convection occurs when a liquid or gas is heated, becomes less dense, and rises. Radiant heat travels in a straight line away from the hot surface and heats anything in its path.

[0005] Mass insulation such as fiberglass, cellulose, or rock wool, effectively reduces heat transfer by convection, and is therefore commonly used in wood frame buildings. To reduce radiant heat transfer, it is known in the art to apply a sheet of reflective material, or “reflective insulation,” between the mass insulation and the interior wallboard. Similarly, in buildings constructed using masonry block walls, where mass insulation is not used, it is customary in the art to attach furring strips to the surface of the wall for applying a sheet of reflective insulation between the block wall and the interior wallboard. Reflective insulation effectively reduces radiant heat transfer and provides convective benefit by creating one or more reflective dead air spaces within the wall cavity. The reduction in convective heat transfer is provided by reducing or dividing the wall cavity into smaller regions.

[0006] Reflective insulation systems are usually fabricated using layers of aluminum foil with a variety of backings such as kraft paper, plastic film, polyethylene bubbles, polymer foam, or cardboard. When installed, the surface of the reflective foil layer(s) should not be in contact with another surface, as this reduces the foil's ability to reflect or block heat. Thus, enclosed air spaces are customarily maintained adjacent to the reflective layers to provide highly reflective or low emittance surfaces facing the enclosed air space.

[0007] The performance of the reflective insulation is determined by three factors. First, the material(s) of the system should have low “emittance,” or “emissivity,” i.e., below 0.10. Emittance is a measure of the energy a material gives off, or emits, by thermal radiation as a result of its temperature. Second, the material(s) should have high “reflectance,” or “reflectivity,” which is a measure of how much radiant heat is reflected by a material. Third, the performance of reflective insulation is dependant on the size of the enclosed air spaces. Accordingly, reflective insulation is typically positioned within the building cavity formed by studs, furring strips, joists, or the like, to provide a highly reflective and low emittance surface facing one or more air spaces.

[0008] When installing reflective insulation near an exterior wall, it is difficult and burdensome to create more than one air space. Typically, studs, furring strips, or other support members are fastened to the inside surface of the wall. The reflective insulation is installed by either (1) inserting the insulation into the cavity created by the support members and attaching it to the sides of the support members to form a single airspace between the insulation and the interior drywall or paneling, or (2) attaching the insulation to the outside surface of the support members to form a single airspace between the insulation and the inside surface of the exterior wall. Thus, to form a second airspace, the second method must be employed and a second layer of furring strips or other support members must be attached between the insulation 100 and the interior drywall or paneling (See FIG. 7). Naturally, a method of creating a second airspace that does not require the time and expense of installing additional support members would be preferred.

[0009] In addition, conventional constructions of reflective insulation can pose several problems. First, many reflective insulation products are troublesome to manipulate, as they tend to be too pliant and require the installer to hold on to the top of the insulating sheet when attaching it to the top of the support member, a task that typically demands the use of a ladder or stool. Second, many constructions are difficult to cut without snagging and require considerable effort to shear. Third, because of the materials used in typical reflective insulation products, the sheets are known to frequently break apart during manufacture, causing more waste and adding to the manufacturing costs.

[0010] Accordingly, there is a need for a reflective insulation and radiant barrier that may be easily installed to create more than one air space in wall cavities formed by the structural members attached to the inside of building walls, that has sufficient rigidity to allow for installation without the need of a ladder, that may be easily cut with a utility knife or similar utensil, and has sufficient tensile strength to withstand the stresses of the manufacturing process and provide a higher production yield.

SUMMARY OF THE INVENTION

[0011] The present invention answers this need by providing a reflective insulation and radiant barrier that is folded during manufacture such that installation in wall cavities to form two or more air spaces may be carried out with ease. Specifically, the present invention relates to a reflective sheet, comprised of kraft paper having two layers of aluminum foil laminated thereto, that is folded to form an insulating panel for positioning between the structural members generally parallel to the building wall, a pair of creases for spreading along the inside surface of the structural members generally normal to the insulating panel, and a pair of tabs for attaching the reflective insulation to the face of the structural members generally parallel to the insulating panel. Accordingly, the length of the pair of creases is such that the insulating panel generally bisects the cavity formed by the structural members to create two dead air spaces.

[0012] It is thus an advantage of the present invention to provide a reflective insulation and radiant barrier that is easy to install and that creates more than one air space within the cavity formed by the structural members attached to the inside of building walls.

[0013] Another advantage of the present invention is to provide a reflective insulation and radiant barrier that increases the insulating benefits of a studded, or otherwise supported, wall at minimal cost during the construction phase.

[0014] A further advantage of the present invention is to provide a reflective insulation and radiant barrier that is easy and inexpensive to manufacture.

[0015] Yet another advantage of the present invention is to provide a reflective insulation and radiant barrier that maximizes the insulation potential of a limited space within a wall cavity.

[0016] An additional advantage of the present invention is to provide a reflective insulation and radiant barrier having a sufficiently rigid structure that permits installation without the necessity of a ladder.

[0017] Another advantage of the present invention is to provide a reflective insulation and radiant barrier that is easy to cut using a utility knife or similar utensil.

[0018] A further advantage of the present invention is to provide a reflective insulation and radiant barrier having sufficient tensile strength to withstand manufacturing stresses and therefore results in higher production yields.

[0019] These and further advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is an end cross-sectional view of a reflective sheet according to an embodiment of the present invention.

[0021] FIG. 2 is an end view of a folded reflective sheet according to an embodiment of the present invention.

[0022] FIG. 3 is a perspective view of a folded reflective sheet that has been rolled during manufacture according to an embodiment of the present invention.

[0023] FIG. 4 is an end view of a folded reflective sheet installed between two vertical support members according to an embodiment of the present invention.

[0024] FIG. 5 is an end view of a folded reflective sheet installed between two furring strips and creating two dead air spaces between a layer of mass insulation and an interior wallboard according to an embodiment of the present invention.

[0025] FIG. 6 is an end view of a folded reflective sheet installed between two furring strips and creating two dead air spaces between a masonry wall and an interior wallboard according to an embodiment of the present invention.

[0026] FIG. 7 is a cut-away view of the prior art showing a reflective insulation installed near an exterior wall between two layers of furring strips.

DETAILED DESCRIPTION OF THE INVENTION

[0027] In an embodiment of the present invention, a multi-layer reflective insulation and radiant barrier intended for use in creating more than one insulating air space in wall cavities formed by parallel structural members attached to the inside of building walls is provided.

[0028] Referring to FIG. 1, a reflective insulation and radiant barrier according to the present invention is fabricated as a multi-layer reflective sheet 10. The reflective sheet 10 consists of a substrate layer 12 having one or more reflective layers 14 and 16 bonded thereto. Because the combination of two reflective layers provides superior heat shielding and heat dissipation, the preferred embodiment of the present invention contains two reflective layers 14 and 16 comprising aluminum foil, each having a thickness of about 0.000250 inches. The substrate layer 12 is preferably made of 25 lb. Kraft paper. Advantageously, the two reflective layers are laminated to the substrate layer 12 using an adhesive lamination process.

[0029] According to this embodiment, the reflective sheet 10 has sufficient rigidity such that it will not yield when grasped from a point slightly below the top of the sheet 10. This provides an advantage during installation, described below. Further, a reflective sheet 10 of this embodiment may be cut using a utility knife or other utensil with relative ease, but has sufficient tensile strength to withstand the stresses incurred during manufacture and reduces the occurrences of tearing. These advantages of the preferred embodiment of the present invention are obtained without sacrificing the thermal performance of the reflective insulation and radiant barrier.

[0030] In other embodiments, the reflective layers 14 and 16 may comprise any highly reflective material such as copper, chromium, nickel, gold, silver, metalized polyester, or the like, or any combination thereof, and may be constructed having any suitable thickness (typically less than 0.005 inches). In still other embodiments, the reflective sheet 10 may be perforated and may only contain one reflective layer 14. The substrate layer 12 may alternatively be made of any material that may be folded, creased, and rolled into a coil, such as reinforced paper; plastic film, flexible cardboard, polymer foam, or the like. It will also be appreciated that the reflective layers 14 and 16 may be bonded to the substrate layer 12 using any conventional bonding technique.

[0031] Referring to FIG. 2, during manufacture, the reflective sheet 10 of the present invention is folded upon itself along its longitudinal edges using a slot folding tray. Such folding creates an insulating panel 20, a pair of creases 22, and a pair of tabs 24, all of which aid in the installation of the reflective sheet 10, subsequently described. The folding of the reflective sheet 10 also facilitates the stacking or coiling of the sheet 10 when in storage after manufacturing and before installation. Accordingly, as shown in FIG. 3, the reflective sheet 10 is delivered to the installer in 16 inch or 24 inch wide rolls, such widths corresponding to the spacing between vertical parallel support members in building construction. It will be appreciated that the reflective sheet 10 may be constructed of various widths if so required by local building codes or a particular installer.

[0032] Referring to FIG. 4, an end view of the folded reflective sheet 10 installed between two parallel vertical studs 40 according to an embodiment of the present invention is shown. To install the reflective sheet 10, the sheet 10 is first grasped at one end by each corner and the tabs 24 are pulled to expand the sheet 10. Starting at the top of the wall cavity, the insulating panel 20 is inserted into the wall cavity between the studs 40 and the tabs 24 are placed directly onto the face of the studs 40. Moving down one side, one of the tabs 24 is then attached by staples 30 or other fasteners to one of the studs 40 by inserting the staples 30 or other fasteners through the tab 24 and into the face of the stud 40 approximately every 6 inches. The creases 22 are then spread along the inside surface of the studs 40 in order to position the insulating panel 20 generally in the middle of the wall cavity. Finally, staples 30 or other fasteners are inserted through the second tab 24 and into the face of the second stud 40 approximately every 6 inches to attach the other side of the reflective sheet 10. Accordingly, two air spaces 50 are formed, one on each side of the insulating panel 20, between the exterior wall and the subsequently installed interior wallboard.

[0033] It will be appreciated that because of the rigidity of the reflective sheet 10, resulting from the Kraft paper substrate and the laminated construction, it is not necessary for the installer to hold on to the top of the tabs 24 in order to attach the tabs 24 to the top of the studs 40. The installer may grasp the sheet 10 from below the top of the tabs 24 without the sheet 10 falling away from the face of the studs 40. Specifically, a reflective sheet 10 of the present invention provides for a maximum length of approximately four (4) feet being unsupported below the top of the sheet 10 during installation. Therefore, the present invention provides for ease of installation in that the use of a ladder or stool is not required.

[0034] Referring to FIG. 5, in another embodiment of the present invention, the folded reflective sheet 10 may be installed near an exterior wall 60 between two parallel vertical furring strips 45 to create two dead air spaces 50 between a layer of mass insulation 70 and an interior wallboard 80. Because the insulating panel 20 generally bisects the wall cavity created by the furring strips 45, the air spaces 50 on each side of the insulating panel 20 have a width of approximately ⅜ inch to ¾ inch.

[0035] Referring to FIG. 6, in yet another embodiment of the present invention, the folded reflective sheet 10 may be installed near a masonry wall 90 between two parallel vertical furring strips 45 to create two dead air spaces 50 between the masonry wall 90 and an interior wallboard 80.

[0036] Although FIGS. 5 and 6 illustrate the reflective sheet 10 of the present invention disposed between furring strips 45, it will be appreciated that the inventive reflective insulation and radiant barrier may be deployed within a number of structures, including but not limited to purlins, joists, studs, or rafters, in a residential or commercial building environment.

[0037] Having thus described the invention in detail, it should be apparent that various modifications and changes may be made without departing from the spirit and scope of the present invention. Consequently, these and other modifications are contemplated to be within the spirit and scope of the following claims.

Claims

1. A reflective insulation and radiant barrier for use in the cavity formed by parallel support members attached to building walls comprising:

a. a reflective sheet;

wherein the reflective sheet is folded to form

i. an insulating panel for positioning between the structural members generally parallel to the building wall,

ii. a pair of creases for spreading along the inside surface of the structural members generally normal to the insulating panel, wherein the pair of creases have a length, and

iii. a pair of tabs for attaching the reflective sheet to the face of the structural members generally parallel to the insulating panel; and

wherein the length of the pair of creases is such that the insulating panel generally bisects the cavity formed by the structural members to create two dead air spaces.

2. The reflective insulation and radiant barrier of claim 1, wherein the reflective sheet comprises a substrate layer having at least one reflective layer thereon.

3. The reflective insulation and radiant barrier of claim 2, wherein the substrate layer comprises kraft paper.

4. The reflective insulation and radiant barrier of claim 2, wherein the at least one reflective layer comprises two layers of aluminum foil.

5. A method of installing a reflective insulation and radiant barrier in the cavity formed by two parallel support members attached to building walls comprising:

a. inserting an insulating panel into the cavity,

b. attaching a first tab to the face of the first support member,

c. spreading a pair of creases along the inside surface of the support members to position the insulating panel generally in the middle of the cavity wherein two dead air spaces are formed, and

d. attaching a second tab to the face of the second support member.