Patent Grant
10895399
The present invention relates generally to HVAC ducts. More particularly, this invention relates to pre-insulated HVAC ducts.
Conventional HVAC ductwork has a variety of limitations. It may have suboptimal thermal insulation properties and/or be non-uniform in terms of thermal insulation properties over its length. In some cases, there may be more air and/or water leakage than is desired. Further, certain ductwork systems include materials that are ideally not exposed to the air circulated within a building. Still further, conventional ductwork may not be as durable as would be optimal. Moreover, some HVAC ductwork is heavy, expensive, or difficult to install. With respect to outdoor ductwork, which is just one relevant category of HVAC ductwork, some ducts are not pre-insulated, and may therefore necessitate having an insulation subcontractor apply thermal insulation to the installed ductwork. Furthermore, it can be inconvenient or difficult to securely mount HVAC ductwork in desired positions and/or to mount components to such ductwork.
It would be desirable to provide a duct construction (e.g., a duct), a ductwork assembly, and a ductwork system that address one or more of the foregoing problems associated with conventional ductwork.
In some embodiments, the invention provides an HVAC duct having opposed first and second ends and a central span extending between the first and second ends. The HVAC duct includes an inner composite tube and an outer composite tube. The inner composite tube has an interior metal wall, a primary foam wall, and an exterior metal wall. The primary foam wall is bonded to both the interior and exterior metal walls of the inner composite tube. The outer composite tube has an interior metal wall, a secondary foam wall, and an exterior metal wall. The secondary foam wall is bonded to both the interior and exterior metal walls of the outer composite tube. The inner composite tube is nested inside the outer composite tube in an end-offset configuration characterized by the inner composite tube projecting axially beyond the outer composite tube at the first end of the duct, whereas at the second end of the duct the outer composite tube projects axially beyond the inner composite tube. Thus, the first end of the duct defines a male detent having a radially-outward-facing metal engagement face projecting axially beyond the interior metal wall of the outer composite tube, whereas the second end of the duct defines a female detent having a radially-inward-facing metal engagement face projecting axially beyond the exterior metal wall of the interior composite tube.
Certain embodiments of the invention provide an HVAC ductwork assembly comprising a first duct and a second duct. The first duct has opposed first and second ends and a central span extending between the first and second ends. The first duct includes an inner composite tube and an outer composite tube. The inner composite tube has an interior metal wall, a primary foam wall, and an exterior metal wall. The primary foam wall is bonded to the interior and exterior metal walls of the inner composite tube. The outer composite tube has an interior metal wall, a secondary foam wall, and an exterior metal wall. The secondary foam wall is bonded to both the interior and exterior metal walls of the outer composite tube. The inner composite tube is nested inside the outer composite tube in an end-offset configuration characterized by the inner composite tube projecting beyond the outer composite tube at the first end of the first duct, whereas at the second end of the first duct the outer composite tube projects beyond the inner composite tube. Thus, the first end of the first duct defines a male detent having a radially-outward-facing metal engagement face projecting axially beyond the interior metal wall of the outer composite tube of the first duct, whereas the second end of the first duct defines a female detent having a radially-inward-facing metal engagement face projecting axially beyond the exterior metal wall of the inner composite tube of the first duct. The second duct has opposed first and second ends and a central span extending between the first and second ends. The second duct includes an inner composite tube and an outer composite tube. The inner composite tube has an interior metal wall, a primary foam wall, and an exterior metal wall. The primary foam wall is bonded to the interior and exterior metal walls of the inner composite tube. The outer composite tube has an interior metal wall, a secondary foam wall, and an exterior metal wall. The secondary foam wall is bonded to the interior and exterior metal walls of the outer composite tube. The inner composite tube is nested inside the outer composite tube in an end-offset configuration characterized by the inner composite tube projecting beyond the outer composite tube at the first end of the second duct, whereas at the second end of the second duct the outer composite tube projects beyond the inner composite tube. Thus, the first end of the second duct defines a male detent having a radially-outwardly-facing metal engagement face projecting axially beyond the interior metal wall of the outer composite tube, whereas the second end of the second duct defines a female detent having a radially-inwardly-facing metal engagement face projecting axially beyond the exterior metal wall of the inner composite tube. In the present embodiments, the first duct and the second duct are joined together by a connection characterized by the male detent of the first duct being received in the female detent of the second duct, such that the exterior metal wall of the inner composite tube of the first duct is nested inside, so as to contact, the interior metal wall of the outer composite tube of the second duct.
In certain embodiments, the invention provides an HVAC duct having opposed first and second ends and a central span extending between the first and second ends. The HVAC duct includes an inner composite tube, an outer composite tube, and an outermost composite tube. The inner composite tube has an interior metal wall, a primary foam wall, and an exterior metal wall. The primary foam wall is bonded to both the interior and exterior metal walls of the inner composite tube. The outer composite tube has an interior metal wall, a secondary foam wall, and an exterior metal wall. The secondary foam wall is bonded to both the interior and exterior metal walls of the outer composite tube. The outermost composite tube has an interior metal wall, a tertiary foam wall, and an exterior metal wall. The tertiary foam wall is bonded to both the interior and exterior metal walls of the outermost composite tube. The inner composite tube is nested inside the outer composite tube, and the outer composite tube is nested inside the outermost composite tube. These three composite tubes are secured in an end-offset configuration characterized by a desired one of the three composite tubes projecting axially beyond the other two of the three composite tubes at the first end of the duct, whereas at the second end of the duct the other two of the three composite tubes project axially beyond the desired one of the three composite tubes. Thus, a leading one of the first and second ends of the duct defines a male detent, while a trailing one of the first and second ends of the duct defines a female detent. The male detent includes a radially-outward-facing metal engagement face. The female detent includes a radially-inward-facing metal engagement face. In some the present embodiments, the female detent includes an axially-outward-facing open pocket surrounded by the radially-inward-facing metal engagement face. Preferably, two of the three composite tubes are in flush-end positions characterized by those two composite tubes being substantially flush with each other at both the first and second ends of the duct. In some cases, the HVAC duct is part of an HVAC ductwork assembly that further includes another duct (these two ducts being defined as first and second ducts). In such cases, the first and second ducts are joined together by a connection characterized by the male detent being received in the female detent such that the radially-outward-facing metal engagement face of the male detent is nested inside, so as to contact, the radially-inward-facing metal engagement face of the female detent.
In one group of embodiments, the invention provides a pre-insulated duct having a length and comprising a tube having a foam layer. In some cases, the duct has two opposed ends, and the tube is centered on a longitudinal axis on which both of the opposed open ends are also centered. The pre-insulated duct has an interior face and an exterior face and a thickness defined as a distance between the interior face and the exterior face. The interior face of the pre-insulated duct bounds an airflow space. In the present group of embodiments, the pre-insulated duct has a mounting rail system extending along the length of the pre-insulated duct. The mounting rail system includes at least one mounting rail, and preferably a plurality of mounting rails, positioned on (e.g., positioned on an exterior of) the pre-insulated duct.
In some embodiments of the present group, the mounting rails are on multiple sides (e.g., on the exterior of multiples sides) of the pre-insulated duct. In addition, on each side of the duct that has one or more mounting rails, there may optionally be only a single rail line extending along the length of the pre-insulated duct.
In any embodiment of the present group, the pre-insulated duct preferably has a plurality of internal braces that are located in the airflow space and that are spaced-apart from one another along the length of the pre-insulated duct. In such cases, each of the mounting rails preferably is attached to the plurality of internal braces at locations spaced-apart along the length of the pre-insulated duct. When provided, the internal braces can optionally have at least first and second rods that are crosswise to each other.
For embodiments wherein the internal braces are provided, each of the mounting rails can optionally be attached to the plurality of internal braces, at locations spaced-apart along the length of the pre-insulated duct, by a plurality of traversal linkage pins that each extend through the thickness of the pre-insulated duct so as to project through the foam layer. When provided, each of the hybrid linkage pins can optionally be: (i) received in a linkage bore formed in the foam layer, and (ii) attached at one end to one of the mounting rails and attached at an opposite end to one of the internal braces.
Certain embodiments of the invention provide a pre-insulated duct having a length and comprising a tube having a foam layer. In the present embodiments, the pre-insulated duct has an interior face and an exterior face and a thickness defined as a distance between the interior face and the exterior face. The interior face of the pre-insulated duct bounds an airflow space. In the present embodiments, the pre-insulated duct includes (e.g., has) four sides and has opposed open ends. The pre-insulated duct has a mounting rail system extending along the length of the pre-insulated duct. In the present embodiments, the mounting rail system includes mounting rails that are positioned on only two of the four sides of the pre-insulated duct. Preferably, the two sides on which the mounting rails are positioned are opposed sides of the pre-insulated duct. In some of the present embodiments, on each of the two sides on which the mounting rails are positioned, there is only a single rail line extending along the length of the pre-insulated duct. In the present embodiments, the tube preferably is centered on a longitudinal axis on which both of the opposed open ends are also centered. In some cases, each of the mounting rails is positioned so as to be at least generally parallel to the longitudinal axis. Furthermore, the pre-insulated duct of the present embodiments preferably has a plurality of internal braces that are located in the airflow space and that are spaced-apart from one another along the length of the pre-insulated duct, and each of the mounting rails preferably is attached to the plurality of internal braces at locations spaced-apart along the length of the pre-insulated duct. When provided, the internal braces can optionally have at least first and second rods that are crosswise to each other.
For the embodiments just described wherein internal braces are provided, each of the mounting rails preferably is attached to the plurality of internal braces, at locations spaced-apart along the length of the pre-insulated duct, by a plurality of traversal linkage pins that each extend through the thickness of the pre-insulated duct so as to project through the foam layer. When provided, each of the hybrid linkage pins can optionally be: (i) received in a linkage bore formed in the foam layer, and (ii) attached at one end to one of the mounting rails and attached at an opposite end to one of the internal braces.
The following detailed description is to be read with reference to the drawings, in which like elements in different drawings have like reference numerals. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Skilled artisans will recognize that the examples provided herein have many useful alternatives that fall within the scope of the invention.
The invention provides a pre-insulated HVAC duct that has exceptional thermal insulation properties and durability. In addition, the duct has an extremely light weight composition, and it has a special multi-tube, multi-wall construction that offers numerous advantages.
As shown in
The duct 10 includes an inner composite tube 890 and an outer composite tube 740. The inner composite tube 890 has an interior metal wall 90, a primary foam wall 80, and an exterior metal wall 100. The primary foam wall 80 is bonded to both the interior 90 and exterior 100 metal walls of the inner composite tube 890. In the present disclosure, the term bonded is used to refer to two walls that are integrally affixed to each other by chemical, adhesive, and/or mechanical means. Thus, the interior metal wall 90, primary foam wall 80, and exterior metal wall 100 of the inner composite tube 890 collectively form a single unitary multi-wall tube 890.
The outer composite tube 740 has an interior metal wall 60, a secondary foam wall 40, and an exterior metal wall 70. The secondary foam wall 40 is bonded to both the interior 60 and exterior 70 metal walls of the outer composite tube 740. Thus, the interior metal wall 60, secondary foam wall 40, and exterior metal wall 70 collectively form a single unitary multi-wall tube 740.
Each metal wall of the duct 10 preferably has a thickness of between 10 micrometers and 2,600 micrometers, such as between 15 micrometers and 300 micrometers. The metal walls of the duct 10 need not all have the same thickness. In one non-limiting example, metal wall 90 has a thickness of about 60 micrometers, and metal wall 100 has a thickness of about 200 micrometers. In addition, metal wall 60 can optionally have a thickness in the range of 50-90 micrometers, while metal wall 70 has a thickness in the range of 50-250 micrometers. In one non-limiting example, metal wall 60 has a thickness of about 60 micrometers, while metal wall 70 has a thickness of about 60 micrometers. In another non-limiting example, metal wall 60 has a thickness of about 80 micrometers, while metal wall 70 has a thickness of about 80 micrometers. In still another non-limiting example, metal wall 60 has a thickness of about 60 micrometers, while metal wall 70 has a thickness of about 200 micrometers.
The inner composite tube 890 is nested inside the outer composite tube 740 in an end-offset configuration characterized by the inner composite tube projecting axially beyond the outer composite tube at the first end 11 of the duct 10, whereas at the second end 19 of the duct the outer composite tube projects axially beyond the inner composite tube. This can be appreciated by referring to
The inner composite tube 890 is nested inside the outer composite tube 740 (e.g., by virtue of a friction-fit, glue, tape, and/or mechanical fastener assembly) such that the exterior metal wall 100 of the inner composite tube and the interior metal wall 60 of the outer composite tube contact each other. A preferred concentric nesting arrangement can be appreciated by referring to
The duct 10 is elongated along a longitudinal axis, which is depicted in
A sloped (or “inclined”) duct roof RF can provide advantageous levels of watershed, e.g., of rain or other precipitation in cases where the duct is mounted outdoors. In the embodiment of
With continued reference to
While not strictly required, the inner composite tube 890 preferably has substantially the same length as the outer composite tube 740. The term “substantially the same” as used herein means no more than 10% different. It is to be understood that the inner 890 and outer 740 composite tubes of the duct 10 can in some cases initially have lengths that differ by more than 10%. In such cases, however, one or both of these tubes would typically be cut down, or “trimmed,” such that the two resulting trimmed tubes have the same length. In many cases, it will be preferred that all the tubes of the duct 10 be of identical length, or at least within 5% of each other, at least once two such ducts are connected (e.g., in embodiments where two such ducts are operably connected to each other, as in
Referring to
In
The walls of the duct 10 desirably are devoid of microfibers. Preferably, the entire duct 10 is devoid of microfibers. In addition, the walls of the duct 10 desirably are devoid of both CFC (i.e., chlorofluorocarbon) and HCFC (i.e., hydrochlorofluorocarbon). Preferably, the entire duct 10 is devoid of both CFC and HCFC.
The foam walls of the duct 10 are self-supporting and preferably are rigid (i.e., not capable of being wound). They preferably comprise a polymer foam. In preferred embodiments, phenolic foam is used, although polyurethane foam or other types of rigid foam can alternatively be used.
The foam walls of the duct 10 preferably each have a thickness in the range of 10-100 mm, such as 15-60 mm. In one non-limiting example, the foam walls each have a thickness of about 20 mm. In another non-limiting example, the foam walls each have a thickness of about 30 mm. In still another non-limiting example, the foam walls each have a thickness of in the range of about 40-45 mm.
In the embodiment of
In other embodiments, the duct includes nine walls. Reference is made to the embodiment of
The foam walls may, for example, comprise (or consist of, or at least consist essentially of) a phenolic resin.
In addition to the noted foam walls and metal walls, the duct 10 can optionally have an outer jacketing material. In some embodiments, the jacketing material forms a vapor barrier that envelopes the entire perimeter, and the entire length, of the duct 10. The jacketing material can be a multi-layer laminate that includes an adhesive facing (e.g., a layer of acrylic adhesive). In the embodiment of
Preferably, each of the duct's metal walls comprises aluminum. While aluminum is preferred, another aircraft metal can alternatively be used. The aircraft metal can be selected from the group consisting of aluminum, titanium, beryllium, magnesium, and alloys comprising one or more of these metals. In other cases, steel may be used.
In certain embodiments, the inner composite tube 890 has metal interior 90 and exterior 100 walls, while the outer composite tube 740 has paper or cardboard liner in place of the metal interior wall 60 and/or in place of the metal exterior wall 70. In embodiments where the duct 10 includes three composite tubes 890, 740, 1740, the outermost composite tube 1740 can optionally have paper or cardboard liner in place of the metal wall 600 and/or in place of metal wall 700.
The foam layers of the duct 10 can optionally have a density in the range of from 40 to 80 kg/m3, such as in the range of from 50-70 kg/m3. In one non-limiting example, the density is about 60 kg/m3.
In preferred embodiments, the interior metal wall 90, the primary foam wall 80, and the exterior metal wall 100 of the inner composite tube 890, as well as the interior metal wall 60, the secondary foam wall 40, and the exterior metal wall 70 of the outer composite tube 740, all have substantially the same length. In many cases, these four walls will all have the same length, or at least be within 5% of one another. This will typically be the case once two ducts 10 are connected, such as in embodiments that provide two such ducts operably connected to each other. Reference is made to
The present duct 10 provides exceptional thermal insulation properties. For example, the duct 10 preferably has an R value of at least 6. In some embodiments, the R value is at least 8. In one non-limiting example, the R value is about 10. In other embodiments, the R value is at least 11. In one non-limiting example, the R value is about 12. In still other embodiments, the R value is at least 14. In one non-limiting example, the R value is about 15. In another non-limiting example, the R value is about 18. The R value of the present duct can be determined using conventional methodology, e.g., in accordance with the well-known ASTM C518 standard for measuring R value, the salient teachings of which are incorporated herein by reference.
In addition to providing exceptional thermal insulation, the present HVAC duct 10 has an advantageous light-weight construction. Preferably, the duct 10 has a weight per unit surface area of less than 3 pounds per square foot of surface area. In some embodiments, the duct 10 has a weight per unit surface area of less than 2 pounds per square foot of surface area. In one non-limiting example, the duct has a weight per unit surface area of about 1.1 pound per square foot of surface area.
One non-limiting method of making the duct will now be described. The duct, as shown on a set of mechanical plans designed by a building engineer, is electronically traced with a CAD (Computer Aided Design) software package, such as that available commercially from AutoDesk under the name of Estimator MEP. The software has been programmed to calculate the amount and configuration of duct panels to be used to make the designed ductwork. Suitable duct panels are available commercially from PAL System International FZCO, of Dubai, U.A.E., e.g., under the tradename Kingspan PalDuct Phenolic panels. The program will output a bill of material that is then programmed into a “SuperCut” software system that is designed to optimize the duct panels for minimal waste of product to produce a projects ductwork. The SuperCut program also controls a CNC (Computer Numerically Controlled) machine. The CNC machine can be, for example, obtained commercially from Alarsis Corte Industrial S.L., of Murcia Spain. The CNC machine has a cutting blade that operates in 5 axes: depth, width, length, blade angle and blade rotation. The CNC machine will follow the program to cut the duct panels as needed to manufacture the duct system. If a duct is of a size where multiple walls of the duct can be used from one panel, the panel will be cut in two (2) 45 degree cuts that form a “V” cut where the bottom aluminum liner is not cut. This allows the panel to be folded from a flat panel into a rectangular duct system. With respect to ducts of larger size that require the side walls to each be made from a different panel, the CNC machine will cut a 45 degree bevel cut and will cut through the bottom aluminum liner. Then the multiple panels each having a 45 degree bevel cut will be assembled into a rectangular duct.
Once one duct (i.e., the interior composite tube 890) is assembled, the CNC machine is programmed to make a 2nd duct (i.e., the outer composite tube 740) such that the inside dimensions exactly match the outside dimension of the inside duct. The 2nd duct is then manufactured around an inside duct in such a manner that the inside duct protrudes at one end by about 3″ (male end) and the exterior duct protrudes by 3″ (female end) on the other end of the duct. The two ducts can be connected by friction fit, sealant, glue, and/or double side tape. The exterior duct is then covered with a plastic liner to protect the duct from visible damage, hail, and/or other items that could dent the outer duct. This plastic liner is applied with a double sided tape. The duct with the plastic liner is then wrapped with the 3M VentureClad 1577 product to complete an air-and-water-tight outer jacketing for the duct system. The VentureClad has a self-adhesive backing to adhere it to the plastic liner. It is to be appreciated that this method is merely exemplary; the foregoing details are by no means limiting to the invention. Other methods can be used to manufacture the various duct embodiments described herein.
The invention also provides embodiments wherein two ducts 10 in accordance with the invention are operably connected to each other. Reference is made to
The two ducts 10 are connected to each other in an end-to-end arrangement. In
The first duct 10 and the second duct 10 are joined together by a connection characterized by the male detent of the first duct being received in the female detent of the second duct. In the embodiment of
The connection preferably includes a radial inner interface, an axial interface, and a radial outer interface. The axial interface desirably extends between the radial inner interface and the radial outer interface. In the embodiment of
Thus, the connection preferably includes first 305 and second 315 beads of sealant. In the embodiment of
In the method of connecting the two ducts 10 shown in
In certain embodiments, the invention provides a building 300 provided with an outdoor ductwork system. In these embodiments, the ductwork system is exposed to periodic contact with rain (and in some cases, also snow and hail). In certain embodiments of this nature, the building 300 has a roof 350 and at least part of the outdoor ductwork system is mounted on the roof. Reference is made to
The ductwork system includes a series of ducts 10, including a first duct 10 and a second duct 10. These two ducts 10 each have a multi-tube, multi-wall construction of the nature described above. The two ducts 10 are joined together by a connection characterized by the male detent of the first duct being received in the female detent of the second duct. The resulting connection is in accordance with the descriptions set forth in the present disclosure.
In the embodiment of
The present duct 10 is by no means required to be used as part of an outdoor ductwork system. In other embodiments, the duct 10 is intended to be used as part of an indoor ductwork system.
As with embodiments where the duct 10 has only two composite tubes of the described nature, the inner 890 and outer 740 composite tubes in
In the embodiment of
In certain other embodiments involving three composite tubes, the outer composite tube 740 projects beyond both the inner 890 and outermost 1740 composite tubes at the first end 11 of the duct 10. Reference is made to
In the present embodiments, the male detent (defined by the outer composite tube 740) at the first end 11 of the duct 10 has both a radially-outward-facing metal engagement face (defined by metal wall 70) and a radially-inward-facing metal engagement face (defined by metal wall 60). The radially-outward-facing metal engagement face projects axially beyond the interior metal wall 600 of the outermost composite tube 1740, and the radially-inward-facing metal engagement face projects axially beyond the exterior metal wall 90 of the inner composite tube 890. In these embodiments, the female detent at the second end 19 of the duct 10 has both a radially-inward-facing metal engagement face (defined by metal wall 600) and a radially-outward facing engagement face (defined by metal wall 100).
In still other embodiments involving three composite tubes, the outermost composite tube 1740 projects axially beyond the outer 740 and inner 890 composite tubes at the first end 11 of the duct 10. In these embodiments, the outer 740 and outermost 1740 composite tubes are affixed to each other, such that one is nested inside the other, in an end-offset configuration. Specifically, the outer composite tube 740 is nested inside the outermost composite tube 1740 in an end-offset configuration characterized by the outermost composite tube projecting axially beyond the outer composite tube at the first end 11 of the duct 10, whereas at the second end 19 of the duct the outer composite tube projects axially beyond the outermost composite tube. Preferably, the inner composite tube 890 is nested inside the outer composite tube 740 in a flush-end configuration characterized by those composite tubes being generally flush with each other at both the first 11 and second 19 ends of the duct 10. In such cases, at each end 11, 19 of the duct 10, the ends of the inner 890 and outer 740 composite tubes are substantially flush with each other.
Thus, the invention provides a variety of embodiments wherein an HVAC duct 10 comprises three composite tubes 890, 740, 1740. In these embodiments, the inner composite tube 890 is nested inside the outer composite tube 740, and the outer composite tube is nested inside the outermost composite tube 1740. In more detail, the three composite tubes 890, 740, 1740 are secured in an end-offset configuration characterized by a desired one of the three composite tubes projecting axially beyond the other two of the three composite tubes at the first end 11 of the duct 10, whereas at the second end 19 of the duct the other two of the three composite tubes project axially beyond the desired one of the three composite tubes. Reference is made to
In the present embodiments, a leading one of the first 11 and second 19 ends of the duct 10 defines a male detent (the end defining the male detent is referred to herein as the “leading” end of the duct), while a trailing one of the first and second ends of the duct defines a female detent (the end defining the female detent is referred to herein as the “trailing” end of the duct). Preferably, the male detent includes a radially-outward-facing metal engagement face (defined by metal wall 100 in
With continued reference to
In the present embodiments, two of the three composite tubes 890, 740, 1740 preferably are in flush-end positions characterized by those two composite tubes being substantially flush with each other at both the first 11 and second 19 ends of the duct 10. In the embodiment of
In the foregoing embodiments involving an HVAC duct 10 having three composite tubes 890, 740, 1740, the duct can be provided as part of an HVAC ductwork assembly that further includes another duct of the nature described above. In such cases, the two ducts (i.e., the “first” and “second” ducts) can advantageously be joined together by a connection characterized by the male detent being received in the female detent. This involves the radially-outward-facing metal engagement face of the male detent being nested inside, so as to contact, the radially-inward-facing metal engagement face of the female detent.
In the embodiments described above, the foam walls of the duct 10 may initially be exposed at both ends of the duct (i.e., a foam end face may be exposed at each end of each foam wall). To protect the foam end faces at each end of the duct, UL181 tape can be applied so as to cover both the male and female ends of the duct 10. This can advantageously leave all the foam concealed.
The present disclosure also provides various ductwork railing embodiments. Reference is made to
The foam layer of the tube preferably is sandwiched between two skin layers (or “facing” layers), which can optionally be thin metal walls formed of aluminum or another metal. In other cases, such skin layers or other walls are formed of polymer. Alternatively, various composites or other materials may be used. While the two skin layers of the tube may have the same thickness, this is by no means required. When provided, each skin layer preferably has a thickness of between 10 micrometers and 2,600 micrometers, such as between 15 micrometers and 300 micrometers. In cases where the duct includes two tubes each having a foam core sandwiched between two skin layers, each skin layer can optionally have a thickness within one or both of the ranges noted in this paragraph. In such cases, the skin layers may, or may not, all have the same thickness.
If desired, the pre-insulated duct can comprise inner and outer tubes that each have a foam layer and that are arranged concentrically one inside the other. In such cases, there are at least two foam layers (i.e., at least two thicknesses of foam) between the inner 5 and outer 7 faces of the pre-insulated duct 10. When provided, the inner and outer tubes can optionally be inner 890 and outer 740 composite tubes of the nature previously described and shown in
Further, it is to be appreciate that in the present embodiments (e.g., any of those shown in
The pre-insulated duct 10 preferably has a square or otherwise rectangular configuration, i.e., in a cross-section taken perpendicular to the longitudinal axis A of the duct. In other cases, however, the pre-insulated duct has a circular configuration. Various other duct shapes can alternatively be used.
The pre-insulated duct 10 has an interior face 5 and an exterior face 7. The thickness T of the duct 10 is defined as the distance between the interior face 5 and the exterior face 7. The interior face 5 of the pre-insulated duct 10 bounds an airflow space (e.g., an airflow channel). Preferably, the airflow space extends along the entire length of the duct 10 (e.g., such that the duct is open on both ends, i.e., has two opposed open ends between which the airflow space extends entirely).
In the present embodiments, the pre-insulated duct 10 has a mounting rail system 20 extending along the length of the pre-insulated duct. The mounting rail system includes at least one mounting rail, and preferably includes a plurality of mounting rails, positioned on (e.g., positioned on an exterior of) the pre-insulated duct. In many cases, the mounting rail system 20 comprises a plurality of mounting rails 20 on a plurality of sides (i.e., on the exterior of a plurality of sides) of the pre-insulated duct 10. Preferably, the mounting rail or rails 25 of the mounting system 20 are an exterior of the duct 10, and in many cases (optionally in any embodiment of the present group) the duct will be mounted at an outdoor location, such as on a roof of a building. In such cases, the mounting rail or rails 25 of the mounting system 20 will typically be exposed to an outdoor environment, e.g., exposed to periodic contact with rain.
In
In
It is to be appreciated that the mounting rails of a given mounting rail line need not be directly aligned with one another. For example, referring to
Further, in embodiments like that shown in
In some embodiments, each duct side that is equipped with the mounting rail system 20 has only a single mounting rail 25 thereon. Reference is made to
In the embodiment of
The mounting rails 25 of the mounting rail system 20 preferably comprise (e.g., are) channel bars. In such cases, each mounting rail 25 has a channel configuration. Thus, as best shown in
The mounting rails 25 preferably are formed of metal, although fiberglass or plastic may alternatively be used. Channel bars suitable for use as the present mounting rails can be obtained commercially from a variety of well-known metal framing manufacturers and other sellers. One example is Unistrut, of Harvey, Ill., USA.
In the present embodiments, the pre-insulated duct 10 preferably has a plurality of internal braces 30. When provided, the internal braces 30 are located in the airflow space (i.e., in the interior channel) of the duct 10 and preferably are spaced-apart from one another along the length of the duct. In such cases, each of the mounting rails 25 preferably is coupled with (e.g., attached to) the plurality of internal braces 30 at locations spaced-apart along the length of the duct 10. In the embodiment of
Each illustrated internal brace 30 comprises first and second rods 35 that are crosswise (e.g., perpendicular, or at least substantially perpendicular) to each other. If desired, the internal braces can each have two or more horizontal rods and two or more vertical rods. This may be advantageous for larger ducts. Each of the rods preferably are metal rods, optionally formed of aluminum or another aircraft metal. The aircraft metal can be selected from the group consisting of aluminum, titanium, beryllium, magnesium, and alloys comprising one or more of these metals. In other cases, steel may be used. In still other cases, the rods may be formed of polymer or composite.
Thus, each mounting rail 25 on the pre-insulated duct 10 preferably is coupled with (e.g., attached to) a plurality of internal braces 30. In certain preferred embodiments, each mounting rail 25 is attached to a plurality of internal braces 30, at locations spaced-apart along the length of the pre-insulated duct, by a plurality of traversal linkage pins 50. This is perhaps best shown in
Thus, referring to
With continued reference to
Turning now to the embodiment of
In the embodiment of
Turning now to the embodiments of
When provided, the roof cap (or least one roof panel thereof) can optionally be positioned at an acute angle relative to a bottom side (e.g., a bottom wall) and/or a top side (e.g., a top wall) of the pre-insulated duct. In such cases, the roof cap is configured to prevent water from accumulating on the top of the duct. In more detail, the roof cap can be configured to shed water (e.g., rain) off the duct. In other embodiments where the roof cap is provided, however, the roof cap may comprise a roof panel that is parallel to a bottom side (e.g., a bottom wall) and/or a top side (e.g., a top wall) of the pre-insulated duct. Such a roof panel may simply be horizontal when the duct is in its operative position. In such case, the roof pane may advantageously be formed of metal.
While the illustrated roof caps define a pitched roof with two angled roof surfaces converging to a roof peak, the roof cap can alternatively be slanted at a single angle across the entire width of the duct.
In some embodiments where the pre-insulated duct 10 has a roof cap 110, there is at least one attachment strap 114 extending from the roof cap to (and attached to) at least one of the mounting rails 25 of the mounting rail system 20. In such cases, the attachment straps 114 can optionally be formed of metal. In the embodiment of
Turning now to
While a single roof truss 115 is shown on the duct 10 of
Furthermore, in certain embodiments, at least one of the mounting rails 25 of the mounting rail system 20 is attached to both (i) at least one component at a top of the pre-insulated duct, and (ii) at least one component at a bottom of the pre-insulated duct. As noted above, the component at a top of the pre-insulated duct may be, for example, a roof cap 110, while the component at a bottom of the pre-insulated duct may be, for example, a support leg assembly 190. Given the present teaching as a guide, it will be apparent to skilled artisans that other types of components can additionally or alternatively be attached to the mounting rail system 20 of the present disclosure.
With reference again to
While some preferred embodiments of the invention have been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.
This application is a continuation-in-part of U.S. Ser. No. 15/081,259, entitled “Multi-Tube Offset Pre-Insulated HVAC Ducting Technology,” filed Mar. 25, 2016, the entire contents of which are incorporated herein by reference.
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| Number | Date | Country | |
|---|---|---|---|
| Parent | 15081259 | Mar 2016 | US |
| Child | 16252145 | US |
