Radiant thermal barrier
Fan-folded panels are provided with longitudinal cuts or fold lines along an extended length of the panels to enable folding of edge sections of the panels into channel walls on either side of an intermediate panel section together forming a channel having a heat reflective surface inside the channel, the channel for insertion between two facing joists or studs so that tops of the channel walls are pushed up against a facing surface supported by the joists to form an air cavity between the facing surface and the channel acting as the radiant thermal barrier. A hydronic under floor heating pipe may be pre-installed attached to the facing surface supported by the joists or studs with the result that a proper air cavity is maintained with the radiant thermal barrier.
The present invention relates to a radiant heat transfer barrier and, more particularly, to such a barrier that is useful in creating a continuous reflective dead air cavity.
Heat transfer through building structures occurs through convection conduction and radiation. In order to retard heat flow by conduction and convection, walls and roofs are built within internal air spaces. Conduction and convection through the air spaces combined represents only 20 to 35 percent of the heat which passes through them. In both winter and summer 65 to 80 percent of the heat that passes from a warm wall to a colder wall or through a ventilated attic does so by radiation.
An increasingly popular form of heating called hydronic heating can be deployed for instance by means of pipes embedded in or affixed behind or under floors, walls, ceilings, etc. between joists or studs. These pipes carry heated water that conduct warmth to the surface of the structure where it broadcasts energy into the living space. To make the system more efficient it is desirable to re-direct energy that is radiated away from the system pipes away from the area to be heated back toward that area. For example, if a radiant floor system is installed under the floorboards above an unheated basement or crawl space, insulation is required in order to isolate the heated floor from the colder space below. It is important to also create an air cavity within which the pipe or pipes reside. A reflector may be laid on the bottom of the cavity on top of the insulation that fills the remainder of the joist bay. The ideal spacing for such a reflector is three-quarter inch or more below the floorboards. Thus, a “radiant thermal barrier system” (RTBS) is in general a building section that includes a radiant barrier facing a dead air space.
Radiant barrier materials may be formed of aluminum foil laminates in which the foil is laminated to kraft paper, card board, plastic films or to OSB/plywood roof sheathing. Or another variation is aluminized plastic films comprising a thin layer of aluminum particles deposited on film through a vacuum process. In both cases, the heat reflective insulation is provided by low emittance surfaces bounding one or more enclosed air spaces. As mentioned, below the reflective radiant thermal barrier material fiberglass or other similar kinds of insulation may be placed to reduce heat transfer between the cavity and the cooler space below (such as a basement).
A typical way to try to create an air cavity for instance between a pair of overhead joists is to loosely place a layer of aluminum foil on top of fiberglass and push the fiberglass with aluminum foil loosely lying on top into the joist bay but not all the way in so as to try to leave a small air space, with the aluminum foil facing the floor board so that radiant heat coming from a pipe installed under the floor and inside the cavity reflects back off the aluminum foil toward the floor board rather than toward the basement. The fiberglass insulation resists additional heat loss through convection and conduction toward the basement.
A problem with this method of installation of a radiant reflective barrier is that it is not easy to judge the proper amount of insertion of the insulation so as to maintain the at least three-quarters to one inch of air space needed to create a proper air cavity between the pipe attached to the floor and the reflective foil lying on top of the fiberglass batting below. A similar problem exists between studs in forming an air cavity for the same or any similar purpose for a wall or a ceiling or for forming a cavity between roof joists and an attic.
SUMMARY OF INVENTIONIt is an object of the invention to provide a combination convective/conductive radiant thermal barrier that is easy to install and provides a consistent air space without difficulty.
According to a first aspect of the present invention, a laminated board is provided of any lightweight construction material having longitudinal cuts along an extended length of the board to enable folding of edge sections of the board into channel walls on either side of an intermediate panel section and forming a channel having a thermal radiant reflective laminar skin inside the channel for insertion between two facing joists or studs so as to be pushed up against a facing surface to form an air cavity including said channel acting as said radiant thermal barrier. Insulation such as fiberglass may then be installed below the radiant thermal barrier.
The longitudinal cuts of the radiant thermal barrier may comprise two pairs of longitudinal cuts including an outer pair cut through the laminar skin on only one side of the adjacent planar sections and an inner pair cut through the laminar skin on the other side of the adjacent planar sections so that the extended length of board is foldable along the inner pair of longitudinal cuts to form an inner layer of the channel walls and is foldable along the outer pair of longitudinal cuts to form an outer layer of the channel walls with the outer layer extending beyond the inner layer so as to form a protruding section that is fastenable to the facing joists or studs.
The heat reflective laminar skin inside the channel may be a metalized laminar skin such as aluminum or any low emissivity surface or coating that reduces radiant energy absorption.
The laminated board may be made of foam such as styrofoam or another plastic material such as extruded polyethylene having a honeycomb core. The laminated board may also be of any other lightweight construction material such as cardboard.
The laminated board may be laminated on both sides with laminar skins and provided with alternating transverse cuts that cut through only one laminar skin, the uncut skin acting as a hinge between adjacent planar sections of the laminated board to enable fan-folding of the laminated board for packaging and transport.
According to a second aspect of the present invention, a thermal panel comprises a first side and an opposing second side with a first edge on the first side and a second edge on the second side and four folding lines substantially parallel to both the first edge and the second edge, the four folding lines comprising a first inner folding line provided on the first side, a first outer folding line provided between the first inner folding line and the first edge, a second inner folding line provided on the second side and a second outer folding line provided between the second inner folding line and the second edge, wherein the four folding lines partition the panel into a plurality of portions comprising a first edge portion between the first edge and the first outer folding line, a first intermediate portion between the first outer folding and the first inner folding line, a middle portion between the first inner folding line and the second inner folding line, a second intermediate portion between the second outer folding line and the second inner folding line, and a second edge portion between the second edge and the second outer folding line, such that when a force is applied about the first outer folding line and about the second outer folding line in a direction substantially perpendicular to the middle portion, the panel is folded into a shape having the middle portion between a first wall on the first side and a second wall on the second side, with the first wall made of the first intermediate portion and the first edge portion, and a second wall made of the second intermediate portion and the second edge portion.
The thermal panel according to the second aspect of the present invention may comprise any lightweight thin rectangular lightweight board material such as plastic, foam, styrofoam, card board or the like.
The material may be cut as in the first embodiment of the invention or may have the four folding lines compressed into the material by means for example of a heated die to enable easy folding. The folding lines may also be created by any suitable methodology which would allow construction personnel to fold-over the edge and intermediate portions to form the first and second walls.
These and other objects, features and advantages of the present invention will become apparent in light of the detailed description of a best mode embodiment thereof as illustrated in the accompanying drawing.
Turning first to
The radiant thermal barrier 10 shown in its extended length in
The act of forming the channel walls is shown in
According to the embodiment illustrated, the outer layer made from the outer edge sections 22, 22′ may be formed of such a length L2 so as to extend downward beyond the shorter length L1 of the inner layer 22 below a main inner part of the channel comprising the panel sections 20 so as to form a protruding length of that edge section 24 below the bottom of the channel inner part.
The radiant thermal barrier shown in
As mentioned, the protruding section of edge section 24 may be used as a surface with which to staple or otherwise fasten the radiant thermal barrier to the inner faces of the joists or studs. Insulation in the form for instance of fiberglass batting may then be pushed into the remaining part of the space between the joists underneath the radiant thermal barrier and affixed to the joists for providing further insulation, mainly against convection of heat from the cavity to e.g., an unheated space such as a basement below.
It should be mentioned again that the transverse cuts 41, 42 and the longitudinal cuts 31, 33 need not be cut all the way through the board to a depth short of the protective film on the other surface but rather may be scored instead on alternate surfaces so as to permit hand-breaking between adjacent panels upon a folding force being applied thereto during the folding part of the manufacturing process in which a block is formed as suggested in
Furthermore, according to a second embodiment of the present invention, there need not be any cuts at all. Rather, the cuts described above in connection with the first embodiment may instead be folding lines pressed into the surface of the material such as by means of a heated die e.g. with a v-shaped knife edge or even a rounded edge. By compressing the lightweight construction material such as cardboard with such a die the folding lines would not actually constitute cuts in the material but would rather merely be impressed into the material to facilitate fan-folding along the transverse folding lines at the factory and after unfolding at the construction site, to likewise facilitate hand-folding along the longitudinal folding lines. Thus, as shown in
The act of forming the channel walls is shown in
Similar to the first embodiment, the second embodiment also may include the outer layer made from the outer edge section 22, 22′ formed of such a length L2 so as to extend beyond the shorter length L1 of the inner layer 24, 24′ below the main channel inner part 20 of the channel and thus form a protruding length of that edge section 22, 22′ to facilitate fastening.
As also with the first embodiment, the radiant thermal barrier of the second embodiment shown in
As mentioned, the protruding section of edge sections 22, 22′ may be used as a surface with which to staple or otherwise fasten the radiant thermal barrier to the inner faces of the joists or studs. Insulation in the form for instance of fiberglass batting may then be pushed into the remaining part of the space between the joists underneath the radiant thermal barrier and affixed to the joists for providing insulation, mainly against convection of heat from the cavity to e.g. an unheated basement below.
Referring back to
These portions include a first edge portion 22 between the first edge 32 and the first outer folding line 33, a first intermediate portion 24 between the first outer folding line 33 and the first inner folding line 31, a middle portion 20 between the first inner folding line 31 and the second inner folding line 31′, a second intermediate portion 24′ between the second outer folding line 33′ and the second inner folding line 31′, and a second edge portion 22′ between the second edge 34 and the second outer folding line 33′.
Referring again to
Although the invention has been shown and described with respect to a best embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and deletions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention.
Claims
1. A radiant thermal barrier, comprising an extended length of board having a laminar skin adhered to each planar surface of said board to form a laminated board, said laminated board having a series of transverse cuts spaced along said extended length through said laminated board and alternately through only one laminar skin, the uncut skin acting as a hinge between adjacent planar sections of said laminated board to enable fan-folding of said laminated board, said laminated foam board having longitudinal cuts perpendicular to said transverse cuts, each cut through only one laminar skin to enable folding of edge sections of said planar sections into channel walls with said board unfolded and extended into said extended length, said channel walls having a heat reflective laminar skin inside a channel formed by said adjacent planar sections and said channel walls folded along said longitudinal cuts for insertion between two facing joists or studs up against a facing surface to form an air cavity including said radiant thermal barrier.
2. The thermal heat barrier of claim 1, wherein said longitudinal cuts comprise two pairs of longitudinal cuts including an outer pair cut through the laminar skin on only one side of said adjacent planar sections and an inner pair cut through the laminar skin on the other said of said adjacent planar sections so that said extended length of board is foldable along said inner pair of longitudinal cuts to form an inner layer of said channel walls and is foldable along said outer pair of longitudinal cuts to form an outer layer of said channel walls with said outer layer extending beyond said inner layer so as to form a protruding section that is fastenable to said facing joists or studs.
3. The radiant thermal barrier of claim 1, wherein said heat reflective laminar skin inside said channel is a metalized laminar skin.
4. The radiant thermal barrier of claim 1, wherein said heat reflective laminar skin is metalized with aluminum.
5. The radiant thermal barrier of claim 1, wherein said heat reflective laminar skin is aluminum foil.
6. A thermal panel, comprising:
- a first side and an opposing second side, a first edge on the first side, a second edge on the second side, and four folding lines substantially parallel to both the first edge and the second edge; said four folding lines comprising:
- a first inner folding line provided on the first side;
- a first outer folding line provided between the first inner folding line and the first edge;
- a second inner folding line provided on the second side; and
- a second outer folding line provided between the second inner folding line and the second edge, wherein the four folding lines partition the panel into a plurality of portions comprising;
- a first edge portion between the first edge and the first outer folding line; a first intermediate portion between the first outer folding line and the first inner folding line;
- a middle portion between the first inner folding line and the second folding line;
- a second intermediate portion between the second outer folding line and the second inner folding line; and
- a second edge portion between the second edge and the second outer folding line, such that when a force is applied about the first outer folding line and about the second outer folding line in a direction substantially perpendicular to the middle portion, the panel is folded into a shape having the middle portion between a first wall on the first side and a second wall on the second side, with the first wall made of the first intermediate portion and the first edge portion, and the second wall made of the second intermediate portion and the second edge portion.
7. The thermal panel of claim 6, further comprising a heat reflective surface on a surface of said thermal panel.
Type: Application
Filed: Mar 16, 2009
Publication Date: Sep 16, 2010
Inventor: David L. Lewis (Bethlehem, CT)
Application Number: 12/404,542
International Classification: E04B 1/78 (20060101);