A FIRE RESISTANT VENTILATION DUCT AND A METHOD OF MANUFACTURING AND INSTALLING SUCH VENTIALTION DUCT

Abstract

A ventilation duct for a fire rated ventilation duct wall penetration has one or more metal sheets forming said duct, wherein said metal sheet duct is covered on the outside by a heat insulating material, and said duct includes elongated stiffening members located on the outside of the duct and attached to said metal sheets. The stiffening members each comprises a metal profile and at least one non-combustible bar of inorganic material. The metal profile is fixed to the metal sheet of the duct and retains the non-combustible bar by at least partly encircling the bar.

Claims

1. A ventilation duct for a fire rated ventilation duct wall penetration, said ventilation duct comprising: one or more metal sheets forming said duct, wherein said metal sheet duct is covered on an outside by a heat insulating material, and said duct includes elongated stiffening members located on the outside of the duct and attached to said metal sheets; wherein the stiffening members each comprise a metal profile and at least one non-combustible bar of inorganic material; and wherein the metal profile is fixed to the metal sheet of the duct and retains the at least one non-combustible bar by at least partly encircling the bar.

2. A ventilation duct according to claim 1, wherein the stiffening members extend transversely to a longitudinal extension of the duct.

3. A ventilation duct according to claim 1, wherein the metal profile is U-shaped with exterior mounting flanges so that a longitudinal groove is provided which is configured to tightly receive the at least one non-combustible bar, preferably two non-combustible bars.

4. A ventilation duct according to claim 1, wherein the at least one non-combustible bar is glued to the metal profile.

5. A ventilation duct according to claim 1, wherein the metal profile is a steel profile.

6. A ventilation duct according to claim 1, wherein the at least one non-combustible bar is based on gypsum, calcium silicate or cement.

7. A ventilation duct according to claim 6, wherein the at least one non-combustible bar does not comprise a heat insulation material.

8. A ventilation duct according to claim 1, wherein the stiffening members are fastened to the metal sheet duct by a plurality of rivets and/or screws.

9. A ventilation duct according to claim 1, wherein the heat insulating material is also arranged on an outside of the stiffening members.

10. A ventilation duct according to claim 1, wherein the heat insulating material is mineral wool, preferably stone wool.

11. A ventilation duct according to claim 1, wherein the duct has a square or rectangular cross-section.

12. A ventilation duct according to claim 1, wherein the stiffening members comprise two or more stiffening members, such as four stiffening members.

13. A ventilation duct according to claim 1, wherein the stiffening members are located along a longer side of the rectangular duct.

14. A ventilation duct according to claim 12, wherein the two or more stiffening members are located along longer sides of the rectangular duct.

15. A ventilation duct according to claim 1, wherein the stiffening members are located on one side and/or both sides of the wall penetration.

16. A ventilation duct according to claim 15, wherein the duct is essentially vertically oriented, and the stiffening members are located on an upper side of the wall penetration, in particular on an upper side of a deck or floor.

17. A method of manufacturing and installing a ventilation duct in a fire rated ventilation duct wall penetration, said method comprising the steps of: providing a ventilation duct section comprising one or more metal sheets forming said duct section; mounting elongated stiffening members located on an outside of the duct section and attached to said metal sheets, wherein the stiffening members each comprises a metal profile and at least one non-combustible bar of inorganic material, wherein the profile is fixed to the metal sheet of the duct section and retains the at least one non-combustible bar by at least partly encircling the bar; and positioning the ventilation duct section with stiffening members through an opening in a building structure, such as a partitioning wall, a deck or a floor; covering said metal sheet duct section and the stiffening members with the non-combustible bars by a heat insulating material; and sealing a gap between an outer surface of the insulation material and the opening in the building structure.

18. A method according to claim 17, wherein the stiffening members extend transversely to a longitudinal extension of the ventilation duct.

19. A method according to claim 17, wherein the metal profile is U-shaped with exterior mounting flanges so that a longitudinal groove is provided which is configured to tightly receive the at least one non-combustible bar, preferably two non-combustible bars.

20. A method according to claim 17, wherein the at least one non-combustible bar is glued to the metal profile.

21. A method according to claim 17, wherein the stiffening members are fastened to the metal sheet duct by a plurality of rivets and/or screws.

22. A method according to claim 17, wherein the heat insulating material is also arranged on an outside of the stiffening members.

23. A method according to claim 17, wherein the heat insulating material is mineral wool, preferably stone wool.

24. A method according to claim 17, wherein the wall penetration may be through a separating building structure, which is either vertical or horizontal in orientation.

25. A method according to claim 1, wherein the gap between the outer surface of the insulation material and the opening in the building structure is sealed, with an intumescent which is capable of swelling when exposed to heat.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In the following the invention is described in more detail with reference to the accompanying drawings, in which:

[0031] FIG. 1 is a schematic cross-sectional side view of a ventilation duct according to the invention installed in a wall penetration;

[0032] FIG. 2 is a detailed cross-sectional view of a stiffening member according to a first embodiment of the invention;

[0033] FIG. 3 is a detailed cross-sectional view of a stiffening member according to a second embodiment of the invention;

[0034] FIG. 4 is a perspective view of a section of a ventilation duct with stiffening members according to the first embodiment of the invention;

[0035] FIG. 5 is a perspective view of a section of a ventilation duct according to the present disclosure, including two stiffening members placed along the longitudinal sides of the duct;

[0036] FIG. 6 is a perspective view of a section of a ventilation duct according to the present disclosure, installed in a wall;

[0037] FIG. 7 is a schematic cross-sectional side view of a ventilation duct according to the present disclosure installed in a wall.

DETAILED DESCRIPTION OF THE INVENTION

[0038] The invention is described below with the help of the accompanying figures.

[0039] It would be appreciated by the people skilled in the art that the same feature or component of the device are referred with the same reference numeral in different figures. A list of the reference numbers can be found at the end of the detailed description section.

[0040] With reference to the figures, a ventilation duct according to an embodiment of the invention is shown. The ventilation duct section shown in FIG. 1 is installed penetrating a vertically oriented light wall 3 of a building structure. As shown in FIG. 4, the ventilation duct 1 has a rectangular cross-sectional shape formed with one or more metal sheets bent into shape for forming the duct. On each of the side walls of the ventilation duct 1 there are mounted stiffening members 4. The stiffening members are provided on the ventilation duct positioned on each side of the wall 3 as shown in FIG. 1.

[0041] The ventilation duct 1 is covered by heat insulation slabs 2 that also extends through the wall opening. The heat insulating material is mineral wool, preferably stone wool. In the opening of the wall 3 through which the ventilation duct 1 is installed, a gap will occur between the outer surface of the insulation material 2 and the opening in a building structure. This gap is filled with a strip of loose insulation fibrous wool material 5 and sealed on both sides with an intumescent material 6, which is capable of swelling when exposed to heat.

[0042] The insulation slabs 2 abutting each other longitudinally in the section of wall penetration are glued together for providing an airtight seal 7 between two abutting insulation slabs 2. This is advantageous since an airtight seal will prevent any draft of air and gasses to pass through the insulation material in case of a fire. Thus, the airtight seal 7 can prevent a fire from spreading from one side of the wall to the other. To prevent any fire risk, the glue is a non-combustible adhesive, based on e.g. cement or a ceramic adhesive.

[0043] In FIGS. 2 and 3 two embodiments of the stiffening members 4 are shown. Common for these two embodiments is that the stiffening members 4 each comprise a metal profile 41 and one or more non-combustible bars 42 of inorganic material and that the metal profile 41 is fixed to the metal sheet of the ventilation duct 1 by rivets 8 or the like and thereby retaining the non-combustible bars 42 by partly encircling the bars. The metal profile 41 is preferably a steel profile.

[0044] In both the embodiments shown in FIGS. 2 and 3, the stiffening member 4 comprises a metal profile 41, which is U-shaped with exterior mounting flanges 44 so that a longitudinal groove is provided.

[0045] In the embodiment shown in FIG. 2, the metal profile 41 is shaped and configured to receive one or more non-combustible bars 42, that essentially fill out the groove. The non-combustible bars 42 are attached to the metal profile respectively to each other by glue 43. On the outside of the stiffening member 4 a layer of insulation material 2a is provided so that the outer surface thereof is essentially flush with the outer surface of the insulation material 2 surrounding the other portions of the ventilation duct. Hereby it is ensured that the cross-section area around the stiffening members 4 is the same as for the rest of the ventilation duct and thereby facilitates the installation of the ventilation duct in a building opening.

[0046] In the embodiment of FIG. 3, the metal profile 41 has a height similar to the insulation material 2 surrounding the ventilation duct metal plates 1. In the groove two non-combustible bars 42 are provided in a tightly fit and in the remaining space in the groove there is provided a strip of insulation material 2a. The metal profile 41 is fixed to the metal plates of the ventilation duct 1 by fasteners 8, such as rivets.

[0047] The duct section may be prepared for installation off-site where there is plenty of space. The metal ventilation duct 1 is provided with stiffening members 4 by assembling the components of the stiffening members 4, whereby the metal profile 41 is fitted with the non-combustible bars 42 and then positioned on the outer metal sheet of the ventilation duct 1. Through the metal flanges 44 and the metal sheet of the ventilation duct 1, holes may be drilled for the fasteners 8 to obtain a ventilation duct section as shown in FIG. 4. This ventilation duct section is then fitted in the building structure opening and finally provided with insulation material (not shown in FIG. 4).

[0048] FIG. 5 shows a perspective view of another embodiment of a section of a ventilation duct according to the present disclosure. In this embodiment of the disclosure, the ventilation duct 1 has a rectangular cross-section, and comprises two stiffening members 4 located along the two opposing longitudinal sides of the duct (only the stiffening member on the upper side is seen in FIG. 5).

[0049] FIG. 6 also shows a perspective view of a section of a ventilation duct according to the present disclosure, where the duct has a rectangular cross-section. The duct is further exemplified to be vertically oriented and installed in a wall 3, more specifically a deck, floor or ceiling, which is penetrated by the duct. The ventilation duct 1 comprises two stiffening members 4 located along the two opposing longitudinal sides of the duct (only the stiffening member on the front side is seen in FIG. 6). On the two opposing short sides of the duct, one or more constructional profiles may be provided. Optionally, the constructional profiles may be any L-shaped profile with one leg abutting the metal sheet outer surface. Those profiles form part of the mounting and bearing system for the duct to be installed in the penetration.

[0050] FIG. 7 shows a schematic cross-sectional side view of the ventilation duct shown in FIG. 6, which is installed in a wall 3, more specifically penetrating a deck, floor or ceiling. The stiffening members 4 are seen to be arranged on only one side of the wall, which is exemplified as being horizontally oriented, whereby the stiffening members are located at the upper side of the penetrated deck. The wall may be any separating building structure, such as a partition wall, a deck, floor or ceiling.

EXAMPLE I

[0051] In an illustrative and non-limiting example, the present invention was implemented in a wall penetration and passed a standard fire test in accordance with DS/EN 1363-1:2012 in conjunction with EN 1366-1:2014 Part 1. The tested horizontal ventilation duct was a standard type from Lindab type LKR with a width of 1000 mm and a height of 250 mm. The ventilation duct was outwardly insulated with stone wool boards with a black aluminium foil and having a nominal density of 120 kg/m.sup.3 and a thickness of 60 mm. The ventilation duct was provided with stiffening members as shown in FIGS. 1, 2 and 4. The stiffening members were U-shaped steel profile with a wall thickness of 1.2 mm and having a height of 26 mm and a width of 60 mm with exterior mounting flanges extending further 25 mm outwards. The stiffening members were attached to the ventilation duct by rivets at each 150 mm. The stiffening members were arranged on all four sides of the ventilation duct approximately 45 mm from each side of a light partition wall with an opening through which the ventilation duct extended. Each stiffening member comprised two fibre gypsum bars, each with a thickness of 12.5 mm. The fibre gypsum bars were glued to the steel profile and to each other by a ceramic glue.

EXAMPLE II

[0052] In another illustrative and non-limiting example, the present invention was implemented in a deck or floor penetration and passed a standard fire test in accordance with DS/EN 1363-1:2012 in conjunction with EN 1366-1:2014 Part 1. The tested vertical ventilation duct was a standard type from Lindab type LKR with a width of 1000 mm and a height of 250 mm. The ventilation duct was outwardly insulated with stone wool boards with a black aluminium foil and having a nominal density of 70 kg/m.sup.3 and a thickness of 60 mm. The ventilation duct was provided with stiffening members as shown in FIGS. 2, 6 and 7 at its long sides above the floor surface, i.e. above the upper side of the deck. The stiffening members were arranged approximately 50 mm above a deck of aerated concrete elements with an opening through which the ventilation duct extended. The stiffening members were U-shaped steel profiles with a wall thickness of 1.2 mm and having a height of 26 mm and a width of 60 mm with exterior mounting flanges extending further 25 mm outwards. The stiffening members were attached to the ventilation duct by rivets at each 150 mm. Each stiffening member comprised two fibre gypsum bars, each with a thickness of 12.5 mm. The fibre gypsum bars were glued to the steel profile and to each other by a ceramic glue.

[0053] The ventilation duct was secured and fixed to the deck at the short sides; angle profiles (L-profiles) of 40×40×3 mm were attached to the metal sheet by means of rivets, and to the deck using concrete screws.

[0054] Above, the invention is described with reference to some currently preferred embodiments. However, by the invention it is realised that other variants may be provided without departing from the scope described herein.

REFERENCE NUMBERS

[0055] 1—Ventilation duct metal plates [0056] 2—Insulation slabs [0057] 2a—Insulation material [0058] 3—Wall, deck, floor or ceiling [0059] 4—Stiffening members [0060] 41—Metal profile [0061] 42—Non-combustible bars [0062] 43—Glue [0063] 44—Mounting flanges [0064] 5—Insultation strip [0065] 6—Intumescent material [0066] 7—Seal [0067] 8—Fasteners or rivets