US20030208976A1

US20030208976A1 - Prefabricated insulation for HVAC ductwork and other fluid conduits

Info

Publication number: US20030208976A1
Application number: US10/141,453
Authority: US
Inventors: Marvin Carroll
Original assignee: Tommie Ann Buchanan Six Mile
Current assignee: Tommie Ann Buchanan Six Mile
Priority date: 2002-05-08
Filing date: 2002-05-08
Publication date: 2003-11-13
Also published as: US6935379B1

Abstract

It is therefore the object of this invention to provide prefabricated insulation sheets, to fit around specific-sized perimeters of duct, which includes methods for anchoring sheets to surface to which they are applied, sealing jacket overlaps to adjacent jackets, and attaching overlapping longitudinal ends of sheets. This prefabrication replaces job-site cutting-to-length of sheets with flanges, as well as the additional step of sealing the exterior of jacket laps after installation, and the attachment of longitudinal ends of sheets with staples. It also provides a method of anchoring the end of sheets to the surface to which they are applied. The invention thereby both improves the installation method and the effectiveness of the attachment thereby improving productivity, reducing costs, and increasing the quality of the installation.

Description

A method for prefabricating insulation for HVAC (heating, ventilation and air conditioning) duct insulation comprising the following steps: Cutting sheets of duct wrap and a jacket attachment-flange; double-faced tape applied to the underside surface of this jacket attachment-flange and the underside surface of the factory provided jacket attachment-flange; installing tabs of jacket with double-faced tape on the non-flanged end; and installing metal or plastic prongs or anchors. This prefabrication eliminates many job-site steps, is safer, and improves quality and efficiency

CROSS REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

This invention relates to the shop prefabrication of material for field installation of insulation for HVAC ductwork and other fluid conduit or systems. More specifically, the invention relates to prefabricated sheets of jacketed flexible fibrous insulation that covers rectangular, square, round, and other shaped sections of heating, air-conditioning, and ventilation ducts and other fluid conduits, inside or outside of buildings.

Insulation of heating, air-conditioning, and ventilation ductwork and other fluid conduits or systems, inside and outside of buildings and in industrial processes, is necessary for energy conservation, temperature control, condensation control, sound reduction, fire protection and other requirements. One form of insulating material for the installation of insulation for these surfaces is flexible faced fibrous blankets manufactured in 4-foot wide and 50-, 75-, or 100-foot lengths. The insulation is available in various thicknesses and densities. It is faced with a laminated jacket of foil, fiberglass strand reinforcement, and kraft paper or other membrane, and has a two-inch facing attachment-flange on one side of the length.

The common procedure today is as follows: The insulation is transported to job site in rolls where it is cut to length, piece by piece, as it is installed. A common procedure is, one workman rolls out the material and makes cuts of the material on the floor near where the system to be insulated is located. The workman usually gets in a kneeling position, or down on hands and knees, as it is otherwise difficult to reach completely across the 4-foot width. Measurement is made for the length to be cut on both edges of the material after it is unrolled onto the floor, and a straight edge is placed on the marks and the cut is made with a knife. The straight edge is moved in two inches from the end and another cut is made through insulation material, being careful to cut only through the insulation but not through the jacketing. The fibrous insulation is then pulled from the jacket on the two-inch width piece leaving a jacketing attachment-flange without insulation.

The workman will then get up from the floor and deliver the cut piece to the installing workman. This is repeated for each piece required. This job-site cutting method is very time consuming and strenuous, subjecting the workman to the possibility of strains and sprains as well as exposing the workmen and other job site personnel to airborne fibers. These fibers may be both an epidermal irritant and a respiratory hazard. On some larger construction projects, such as hospitals, the insulation of ductwork may take many months to complete.

The applicator places the cut piece around the duct and the opposite longitudinal ends are pulled together, overlapping the flange from one end over the opposite end. The flange is then stapled to the jacket of the opposite end with a flare-type staple. Failure of the flare-door-type staple guns is common, and since many job sites are in remote locations, the failure of the staple gun delays work and increases costs. After stapling is completed, the applicator applies a pressure sensitive tape of similar type as the blanket jacket over the staples and over the edge of the attachment-flanges, both circumferential and longitudinal joints. Care must be taken to make sure that every joint is sealed completely.

If the joints are not completely sealed on the insulation jacketing installed on duct such as air conditioning duct, which operates at a temperature lower than ambient temperature, moisture will enter the insulation making the insulation wet and ineffective. This results in condensation drips that damage ceilings and interiors of buildings. Molds may result from this wet insulation and wet surfaces resulting in damage and an indoor air pollution problem.

For rectangular or square ducts having a width of over 24 inches, insulation anchors may be installed prior to installing the insulation. The anchors may be installed on the surface of the bottom of the duct or as required to hold the insulation tight to the surface.

The technique for installing insulation on heating, air-conditioning, and ventilation ductwork and other fluid conduit has changed minimally over the last 30 to 40 years. Prior to that time, suitable pressure-sensitive tape was not available and a liquid adhesive was brush applied under the overlap flanges or a mastic coating, with or without reinforcement, was used over all joints to achieve a seal. Even though this mastic type application takes considerably more time, it is specified today by some engineers who do not trust that workmen will achieve a good seal with the pressure sensitive tape application.

Improved methods utilizing factory applied contact cements with release strip have been utilized for sealing molded fiberglass pipe insulation jackets since the 1970's. Typical of such closures are U.S. Pat. Nos. 3,849,240: 4,022,248; 5,104,701; 5,234,520, 5,123,453 and 5,736,211. All of these patents are for improved sealing of pipe insulation and jacketing with the U.S. Pat. No. 5,736,211 for an improvement using an external band of jacket seal for butted edges. U.S. Pat. No. 5,104,701 is for a two-part application of non-tacky, moisture resistant strip and tape and adhesive systems that may be applied to pipe and duct insulation. The application for duct insulation is applied to the external surface of the jackets. My invention utilizes sealant on the underside of jacket attachment-flanges. Major uses of these patents are for improvement of pipe insulation and none address any prefabrication of heating, air-conditioning, and ventilation ductwork, or other fluid conduit or system insulation.

A cutting device for cutting duct wrap, U.S. Pat. No. 5,086,680, addresses an improved method of cutting fibrous duct wrap blanket and utilizes a long handle to avoid the necessity of getting down on floor for cutting. Although that device provides a method of cut off for blanket insulation, it may still be necessary to get on the floor for measurement and marking. That device is a cut-off device, which will cut through both the insulation and jacketing, but it will not satisfactorily cut through insulation only. The conventional means of cutting away insulation from jacket would be required for fabricating jacket attachment flanges.

In most construction trades, there is a shortage of skilled craftsmen, and job-site productivity is low making costs high for job-site installation. This results in prefabrication and unitized construction being more widely used. Typical of such prefabrication are U.S. Pat. Nos. 5,285,609; 6,050,045; 6,311,446; and 6,318,044. Pre-engineered metal buildings are a good example of the utilization of prefabrication and metal buildings are the most widely-used construction for one story warehouse, shop, and small to medium sized manufacturing facilities.

There is therefore a need for improved productivity, cost reduction and quality of installation of fibrous blanket duct insulation.

BRIEF SUMMARY OF THE INVENTION

It is the object of this invention to provide a method for prefabricated insulation sheet for HVAC ductwork and other fluid conduits allowing much of the work historically done on the job site to now be done in the shop. My invention eliminates some problems normally encountered on the job site and allows the shop work to be done in a more productive manner and at a lower labor cost. The object of this invention is to provide prefabricated sheet that fits around specific-sized perimeters of duct and includes installed tape for sealing jacket overlaps to adjacent jackets. The installation of the tape with release strips not only provides a way to easily seal the jacket without applying additional tape over the outside, it also adds rigidity to the jacket flanges before it is removed during application. This therefore eliminates the previous problems caused by the jacket flanges becoming folded or rolled under the insulation. This improves the installation method and effectiveness of seal thereby improving productivity, reducing costs, and increasing the quality of installation. This is in addition to health benefits achieved through this invention through ergonomics and improved fiber control.

It is further an object of this invention to provide an insulation sheet with affixed adhesive tabs to hold the longitudinal end in place on the surface of the duct. With the end anchored to the surface, the entire sheet may be placed around the duct and the longitudinal ends may be attached with ease.

It is further an object of this invention to provide a prefabricated insulation sheet with affixed metal or plastic prongs, tabs, or anchors thereby creating an easy means of attachment of the ends of the sheet without the use of a staple gun and providing a means of easily attaching the sheet to the surface of the duct. Metal or plastic prongs, tabs, or anchors, through the jacket on the non-attachment flange end or other locations, facilitates the attachment of the flange end in an overlapping position, and in other locations secures insulation to the surface to prevent sagging. This invention provides means to accomplish easy and quality installation of flexible fibrous insulation with jacket to HVAC ductwork and other fluid conduits.

These objectives and other objectives of this invention are thus accomplished by providing attachment-flanges with contact adhesive with release strips on one end and on one side of the insulation sheet. Jacket tabs with contact adhesive with release strips on the non-attachment flange end facilitates the attachment of the end to the surface onto which it is positioned. These insulation sheets are installed onto ductwork in succession thus providing complete insulation of the entire duct system.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be better understood when viewed with the following drawings wherein: [0021]
FIG. 1 is an isometric view of a typical roll of flexible fibrous blanket insulation with jacket facing, for reference showing the jacket flange on one side of the roll; [0022]
FIG. 2 is an isometric view of a prefabricated piece of flexible fibrous blanket insulation with jacket facing attachment flanges on one longitudinal end and on one circumferential side, both with pressure sensitive contact adhesive strips with release strips, and with jacketing facing attachment tabs with pressure sensitive contact adhesive strips with release strips on the non-flanged longitudinal end; and with installed metal prongs in jacketing of the longitudinal non-flanged end; [0023]
FIG. 3 is an isometric view of attachment of the longitudinal non-flanged end of a prefabricated piece of flexible fibrous blanket insulation to a section of HVAC duct by attachment of jacketing tabs with pressure sensitive contact adhesive strips and release strips. [0024]
FIG. 4 is an isometric view of a further step of securing the prefabricated piece of flexible fibrous blanket insulation to a section of HVAC ductwork by impaling the longitudinal flanged-end over the metal prongs located on the non-flanged longitudinal end, sealing jacket-flanges and bending the metal prongs tight against the jacket-flange. [0025]
FIG. 5 is an isometric view of a further step of installing a second prefabricated piece of flexible fibrous blanket insulation to a section of HVAC ductwork with the same installation sequence and the second prefabricated piece of flexible fibrous blanket insulation is abutted to the first piece along the circumferential edge and the jacket flange with the pressure sensitive contact adhesive and release strip overlapping the adjacent piece. The release strip is removed from the circumferential pressure sensitive adhesive strip and the seal is complete as the sheet is wrapped around the ductwork section.[0026]
Many variations of the above invention may be apparent to those skilled in the art from the reading of the description, which is exemplary in nature. Such variations are embodied within the spirit and scope of this invention as measured by the following appended claims. [0027]

DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The subject invention has application wherever the insulation of duct or other fluid conduits is necessary using flexible fibrous blanket insulation with jacket. However, the invention as seen in FIGS. [0028] 1-6 will be described in the embodiment of insulation on a straight section of round HVAC ductwork. The invention can be used in the insulation of other shaped surfaces of ductwork or conduits including various fitting shapes.
As best seen in FIG. 1, insulation material [0029] 1 with jacket 2 from manufacturers is in rolls and is equipped with one jacket attachment-flange 3 that may be partly rolled under or folded.
As best seen in FIG. 2, a sheet of insulation material [0030] 1 with circumferential jacket flange 4 and with longitudinal jacket flange 5 has been cut into length to fit around the perimeter of a section of straight duct .
As best seen in FIG. 2, a [0031] tape member 8 having an adhesive backing 9 which is typically covered by a conventional release paper 10 is secured to the inner surfaces of the longitudinal jacket flange 5 and also is secured to the inner surfaces of the circumferential jacket flange 4 resulting in the circumferential jacket flange 4 to be smooth, stiffened and unrolled.
FIG. 2 shows the [0032] release paper 10 is partially removed from ends of tape members 8 at the corner where circumferential 4 and longitudinal 5 jacket flanges intersect. As best seen in FIG. 2, attachment tabs 12 are shown with the conventional release paper 10 partly removed and the tabs affixed to the jacket of the non-flanged longitudinal end 13 with the remainder of the tabs not affixed to the jacket 2 and with the adhesive strip and release strip in place.
As best seen in FIG. 3 a sheet of insulation material I has been placed partially around [0033] duct section 14 is seen with the non-flanged longitudinal end 13 attached to the duct section 14 by removing the release strips from the adhesive on the attachment tabs 12 and adhering the attachment tabs 12 to the duct section 14 with the metal or plastic prongs 11 in place.
As best seen in FIG. 4 the sheet of insulation with longitudinal jacket-[0034] flange end 5 has been placed around the duct section 14 and release strips have been removed from the longitudinal jacket-flange 5 and the longitudinal jacket-flange 5 is adhered to the non-flange longitudinal end 13 of the piece and the metal prongs 11 are installed in the jacket 2 of the non-flanged longitudinal end 13 and are impaled and laid down on the longitudinal jacket-flange 5.
As best seen in FIG. 5, one cut sheet of insulation with [0035] jacket 2 is in place around the perimeter of a section of straight duct 14 with longitudinal end jacket flange 5 overlapping non-flange longitudinal end with the end of attachment tabs 12 showing and with the attachment prongs 11 bent over in place. The depiction illustrated in this view is accomplished after the release strip has been removed and the longitudinal flange adhered to the non-flange end jacket.
As best seen in FIG. 5 a second cut sheet of insulation [0036] 1 with jacket 2 has been placed partially around duct section 14 is seen with the non-flanged longitudinal end 13 attached to the duct section 14 by removing the release strips from the adhesive on the attachment tabs 12 and adhering the attachment tabs 12 to the duct section 14 with the metal or plastic prongs 11 in place is abutting the first piece applied with the circumferential jacket-attachment-flange 4 partially adhered to the jacket 2 of the first piece and the release 10 partly removed for adhesive strip 9 on the longitudinal end jacket flange 5.
Successive pieces of prefabricated flexible fibrous blanket insulation are applied to ductwork as depicted in FIGS. [0037] 1-5 completing the entire ductwork system insulation.
Many variations of the above invention may be apparent to those skilled in the art from the readings of the description, which is exemplary in nature. Such variations, may include installing tape with release strip partially removed on outside surface of flanges and variations are embodied within spirit and scope of this invention as measured by the appended claims. [0038]

DETAILED DESCRIPTION OF THE INVENTION

This describes a method and system for insulating rectangular, square, round, and other shaped sections of heating, air-conditioning ductwork, and other fluid conduits, inside and outside buildings, using prefabricated fibrous duct insulation which is quick and easy to install. For wrapping ducts, a prefabricated system of sheets of insulation, with jacket, with longitudinal and circumferential jacket flanges that have double-faced tape with release strip on the underside of flanges for pressure adhesion construction is provided. The jacket flanges are for attaching the two longitudinal ends together and also for attaching the circumferential jacket flange to the adjacent installed piece. Included are adhesive tabs for attachment of non-flange longitudinal end to surface of duct. Also provided is a mechanical attachment provision consisting of pronged metal or plastic tabs or anchors for the attachment of the two overlapping longitudinal ends together and/or anchoring the blanket to the surface of the duct. Prefabricated pieces are plastic sheet shrink-wrapped to minimize fiber disbursement during transportation and job-site handling. [0039]

Claims

What I claim as my invention is:

1. Prefabricated insulation for HVAC ductwork and other fluid conduits.

(a) A plurality of prefabricated sheets of flexible fibrous insulation blanket with jacket with each sheet to fit around the perimeter of specific-sized ductwork, with each sheet having one longitudinal edge jacket-flange and one circumferential edge jacket-flange with self sealing tape with release strips on both the longitudinal and circumferential jacket-flanges undersides.

(b) A plurality of prefabricated sheets of flexible fibrous insulation blanket with jacket to fit around the perimeter of specific-sized ductwork, with each sheet having jacket tabs with self-sealing tape with release strips, with release strip removed from ½ the length of each tab with ½ the length of each tab adhered to the non-flange end of the sheet.

(c) The plurality of prefabricated sheets of flexible fibrous insulation blanket with jacket to fit around the perimeter of specific-sized ductwork, with each sheet having metal and/or plastic attachment prongs, pins, or anchors in the non-jacket-flange longitudinal end jacket and or in other locations on the sheet, such as locations to prevent sagging in the blanket sheets.

2. A method of installing a plurality of prefabricated sheets of flexible fibrous insulation blanket with jacket onto HVAC ductwork or other fluid conduits comprising:

(a) providing a prefabricated insulation for HVAC ductwork and other fluid conduits having one longitudinal edge jacket-flange and one circumferential edge jacket-flange with self-sealing tape with release strips on both the longitudinal and circumferential jacket flanges undersides; i) with each sheet having jacket tabs with self-sealing tape with release strips, with release strip removed from ½ the length of each tab with ½ the length of each tab adhered to the non-flange end of the sheet; ii) with each sheet having metal or plastic attachment prongs, pins, or anchors in the non-jacket-flange longitudinal end jacket and or in other locations on the sheet, such as locations to prevent sagging in the blanket sheets.

b) removing the release strips from the self-sealing adhesive tabs on one sheet, placing the sheet onto the ductwork and adhering the tabs to the ductwork surface.

(c) placing said sheet around said ductwork and removing the release strips from the self-sealing adhesive on the longitudinal end jacket-flange of the sheet and adhering the jacketing-flange to the abutting jacket surfaces.

(d) impaling the metal or plastic prongs, pins, or anchors on the sheet through the overlapping jacket-flange and securement of said jacket-flange by folding or attaching the metal or plastic prongs or anchors, tight against the surface of the jacket-flange or other securement on other jacket surface.

(e) applying additional prefabricated sheets in succession onto ductwork or fluid conduit with the circumferential jacket-flange overlapping the circumferential end of the previously applied sheet removing the release strip from the circumferential jacket-flange and adhering the circumferential jacket-flange to the abutted sheet jacket to accomplish complete insulation of ductwork or conduit system.