GB2513332A

GB2513332A - Improvements in fire dampers

Info

Publication number: GB2513332A
Application number: GB1307296.2A
Authority: GB
Inventors: Andrew Frederick Sargent
Original assignee: ADVANCED AIR UK Ltd
Current assignee: ADVANCED AIR UK Ltd
Priority date: 2013-04-23
Filing date: 2013-04-23
Publication date: 2014-10-29
Also published as: WO2014173584A1; GB201513587D0; GB2557865A; GB2557865B; GB201307296D0

Abstract

A bracket 8 for securing a fire-damper 5, having a fire-damper engaging member 10 and an elongate suspension member 12. The engaging member 10 having an adjustable connector to allow the suspension member 12 to be connected to the engaging member 10 at a number of positions relative to the length of the suspension member 12. Also provided is a fire damper 5 with elongate suspension members 12 each side of the damper 5. There is also a method of installing an air duct using the damper bracket 8 where the fire damper 5 is secured to the ceiling by use of the suspension member 12, constructing a wall (6, Figure 4) surrounding the periphery of the fire damper 5 and connecting air ducts (1, Figure 4) to the fire damper 5. The ability to vary the relationship between engaging member 10 and suspension member 12 allows for movement of the fire damper 5 between instalment of fire damper 5 and building of wall (6).

Description

IMPROVEMENTS IN FIRE DAMPERS

Field of the Invention

The invention relates to fire dampers, brackets for securing fire dampers and methods of installation of air ducts, particularly for use in heating, ventilation and air-conditioning systems, where such ducts include fire dampers.

Backzround and Prior Art

The provision of air ducts throughout buildings to provide heating, ventilation or air conditioning is very common, cspccially in large buildings where forced air provision is often essential. The ducting conmionly connects a large number of otherwise is distinct, regions of t.he building providing air services froni one or more centralised air handling units.

Whilst such air handling networks are advantageous for building design and management, the connectivity of different regions of a building introduced by the ducting could he problematic in the case of fire. Not only can hot or burning gases be conveyed along the ductwork, thereby spreading the fire throughout the building, but smoke produced by the fire in one part of the building could be readily and rapidly conveyed to other parts of the building that would he otherwise unaffected.

In order to prevent, such problems, air duet. systems within buildings arc provided wit.h fire-damprs that can be actuated in the event of fire to prevent flow along the air ducts. Such fire dampers may he passively-operating devices comprising e.g. spring-actuated flap valves or louvers held in an open position by means of a fusible connection. The fusible connection is chosen to melt when the temperature of the so duct contents exceeds a pre-set temperature. Tn this way, the dampers are automatically actuated in the case of fire, when hot gases pass along the duet. In other active systems, the dampers might comprise a smoke detector that can be used to trigger actuation of a flap valve or louvers in the presence of smoke particles in the duct's air flow. In this way, the dampers can be actuated even in the absence of high-

I

temperature gases. Such dampers may also he referred to as smoke dampers or fire/smoke dampers. The term "fire-damper" or "damper" is used herein to refer 10 any such type of damper. Dampers may also be triggered Lo operate by signals from a fire-protection system, allowing the ducts to be shut down even before smoke or hot a gases have reached them.

Fire dampers are typically used where air ducting passes through fire-resistant walls and floors, thereby allowing adjacent regions in a building to he isolated from each other in respect of Lhe spread of fire, smoke and other gaseous products of to combustion.

Whatever type of damper is to be used, challenges arc encountered when installing such air duct. systems, particularly in new buildings. A typical installation process is illustrated in Figures 1 and 2. lypically, a first air duct I will be installed by is suspending it from a ceiling 2, often by means of a strap 3 surrounding the duct I that is hung from the ceillng 2 by a threaded suspension rod 4. When referring to "ceiling" in the context of installation, this is used herein to refer to a generally horizontal support plane above the installed ducting. In commercial premises, this is likely to he e.g. the concrete slab between floors of the building. A decorative "suspended ceiling" might then he installed below the ceiling slab to enclose and hide the ductwork. The ducts are often of square section, and fabricated from metal. The damperS is then connected to the end of the first duct 1, and a seal is made between the damper and the duct 1. A second section of duct 1' is then connected to the other side of the damper 5, itself being suspended from the ceiling by e.g. a rod and strap arrangement. It is noted dm1 such installations are olten carried out helore the internal fire-resistant walls have been built. In a second stage of the process therefore, illustrated in Figure 2, a fire-resistant wall 6 is constructed surrounding the periphery olthe damper, and a seal is made between the wall and the damper, using e.g. lire-resistani morlar.

During the installation process, which might take place of a period of several weeks, the damper 5 is prone t.o damage and dislocation, particularly from rotation forces exerted on it by the duet, if only onc side of the duct has been installed. I urthcrmorc, the exact final position of thc wall 6 associated with the damper might not he known when the air ducting is installed, and fine adjustment of the damper position is difficult, further leading to possible damage, either of the damper or of the seal between the damper and the duct.

a It is only after the wall has been built that the damper 5 is properly secured, either by the mortar that is used between the damper 5 and the opening in the wall 6, or by the use of a bracket (not illustrated) that supports the weight of the damper on the wall.

once built.

to Another problem in installation of fire dampers and associated ductwork in buildings is that the current mode of installing dampers does not allow the position of support members for the dampers to be adjusted to avoid other building elements (such as pipes and cables) that might. be adjacent 1.0 the damper. Installation of the dampers is crucial to the safety of the building and its occupants, and the damper support is mechanisms must he able to withstand the intense heat that they might he subjected to in the event of fire. Ad-hoc solutions are not. acceptable, as the installation mechanisms and procedures must be thoroughly tested before they may be used.

There is a requirement, therefore, for a damper support system that allows for such installation flexibility, whilst allowing for the various configuration options to he tested.

It is amongst the objects of the present invention to attempt a solution to these problems.

Summary of the Invention

Accordingly, the invention provides a bracket for securing a fire-damper, said bracket comprising: a fire-damper engaging member; and an elongate suspension member; said fire-daniper engaging member having an adjustable connector to allow said suspension member to he connected to said engaging member at a plurality of positions relative to the length of said suspension member. In this way, suspension members may be so sized and positioned such that. they extend each side of the engaging member (and therefore potentially each side of the damper) to allow fixing to a cciling on either side of a wall surrounding the damper. Alternatively, the suspension member may he so sized and positioned such that it extends just to one side of the engaging member (and therefore polentially lo one side of the damper) allowing fixing to a ceiling on one side of the wall surrounding the damper, or lo lhe wall itself. In another alternative, a short elongate suspension member may be used, a such that the damper can he supported essentially centrally. ftc support member and various lengths of suspension member can, in this way, be thoroughly tested in a range of configurations, whilst allowing immediate on-site adjustment to provide a range of safe installation options.

to Preferably said fire-damper engaging member comprises a clasp configured to clasp an edge region of a fire-damper. the clasp can sit around the edge of a fire damper, and bc permanently affixed there, for cxamplc by welding or another heal-stable fixing.

is In either aspect of the invention it is preferred that said connector is configured to allow relative sliding movement, of said suspension member relative to said engaging member. Such a sliding connector allowing the suspension member to slide along its elongate axis allows the suspension member to he positioned conveniently for the prevailing installation demands.

It is further preferred that a reversible locking member is provided to lock said engaging member to said suspension member, thereby preventing said sliding movement.

l'he invention also provides a fire-damper comprising an elongate suspension member extending each side of said damper in a direction parallel to the flow axis of the fire-damper. Preferably said fire damper comprises two such suspension members, More preferably, the or each suspension member is arranged for slideahle connection with said damper in a direction parallel to the flow axis of the fire-damper.

The invention also provides a fire damper assembly comprising a fire damper and a bracket. described herein.

Ihe invention also provides a method of installing an air duct incorporating a fire damper comprising the steps of: providing a fire damper assembly described above; securing said nrc damper Lo a ceiling by use of said suspension member; constructing a wall surrounding the periphery of said fire damper; and connecting an air duct to a said fire damper.

Also included in the scope of the invention is a bracket for securing a fire-damper substantially as dcscribed herein with reference to and as iflustrated by any appmpriate combination of the accompanying drawings.

Also included in the scope of the invention is a fire damper substantiafly as described herein with reference to and as illustrated by any appropriate combination of the accompanying drawings.

is Also included in the scope of the invention is a method of installing an air duet substantially as described herein with reference to and as illustrated by any appropriate combination of the accompanying drawings.

Brief Description of the ligures

The invention will be described with reference to the accompanying drawings, in which: Figures 1 and 2 show prior art methods of installing a fire damper; Figures 3 and 4 show apparatus and methods of the invention for installing a lire damper; Figure 5 is a perspective view of a fire damper and bracket of the invention; Figure 6 is a perspective view of a fire-damper engaging member; and Figures 7-9 show alternative damper and bracket instalbtion options.

Description of Preferred Embodiments

l'igure 3 illustrates, in side elevation view, a damper installation system of the present invention, generally indicated by 7. In this embodiment, a damper 5 is supported by a damper bracket 8 comprising an elongate suspension member 9 connected to a damper-engaging member 10. The suspension member 9 extends each side of the damper. In this way, the suspension member 9 may be attached to a ceiling 2 by means of suspension rods 4 either side of the damper. As a result, the damper is a always supported from cach side, providing support against rotational forces that will be encountered during installation of the ductwork.

I'igure 4 illustrates, again in side elevation view, further stages of the process of ductwork installation. Ducts 1 may again be connected to either side of the damper 5 to and, usually at a later stage in the installation, fire-resistant walls 6 may be constructed around the damper. By contrast to the existing system of installation described above, where the damper is only properly supported once the wall has becn constructed, in (his way, (he damiper 5 is always supported by the improved support means, and furthermore the damper is supported from both sides, allowing rotational is forces to be resisted.

In particularly preferred embodiments of the invention, the connection between the elongate support member 9 and the damper-engaging member lO is slideable along an axis parallel to the flow axis of the duct, so that the position of the damper may he adiusted relative to the suspension point (i.e. to the ceiling). Arrangements for this are described below.

Figure 5 illustrates in perspective view, a bracket, generally indicated by 8, secured to each side of a lire damper 5. Each brackel. comprises a fire-damper engaging member 10 and an elongate suspension member 9. In this embodiment, the engaging member lOis configured to wrap around the edges 11 of the periphery of the fire damper mechanism allowing it to be secured thereto by e.g. self-tapping screws, adhesive, or other means. Ihe elongate suspension meniher 9 is Rrmed as an [-shaped section, giving it rigidity against the bending forces excited on it in use. the suspension memlr is also provided with a series of holes 12 to allow support rods (not illustrated) to he inserted at convenient points for suspension from a ceiling. As will illustrated more clearly in Figure 6, the damper engaging member 10 is provided with a connector in the form of an 1.-shaped slot through which the elongate support member 9 can pass, in sliding cngagement, to allow the damper to he positioned relative to the sUpport menihers 9. In this embodiment, a nut and bolt 13 is used as a locking member Lo hold the daniper in position relative 10 Lhe elongate support members 9, once the required position has been determined. In this embodiment, the same series of holes 12 are used for this purpose, hut it is envisioned that in a alternative embodiments a diffcrent form of locking member might he employed, such as a reversible clamping arrangement.

I igure 6 illustrates, in perspective view, a fire-damper engaging member, generally indicated by 10, for use as part of a bracket to secure a fire damper. The engaging to member is of two part construction, made of metal. The first part is formed to have side pieces 14 that wrap around the edges 11 of a fire damper 5 to he supported. A slot formed in thc sidc pieces 15 and the front region 16 of thc bracket forms an L-shaped receiving slot, for receiving the elongal.e support. members 9 (not. illustrated).

An upper abutment portion 17 serves to keep the I rshaped slot away from the edge of is the damper once installed. An angled clamp member 18 engages with a second slot 19 and proves means for the locking miechanismi to engage the engaging menther 10 with the support member 9.

I'igure 7 illustrates, in side view, a fire damper 5 with a support bracket comprising a fire damper engaging member and an elongate suspension member 9 where the suspension member 9 has been positioned such that it extends only to one side of the damperS. [he suspension member 9 is supported from a ceiling 2 by suspension rod 4. The wall surrounding the fire damper is not illustrated, for clarity.

Figure 8 illustrates an alternative conliguration in which the support member 9 again extends to just one side of the damperS, locked into position relative to the damper engaging member 9 by means of the locking member 13. The support member 9 is, in this conFiguration, supported by a suspension rod 4 attached to the wall 6 via a bracket 20. le gaps between the wall 6 and damper S will be filled with fire-proof material.

Figure 9 illustrates a yet further configuration in which a short elongate suspension member 9 is employed and the damper assembly is suspended by a suspension rod 4 essentially centrally located either side of the damperS. [his configuration might he used where the wail 6 comprises a studwork wall. Again, fire-proof material 21 is used lo seal the gap beiween the damper 5 and the wall 6.

Like elements of examples and embodiments have the same reference numbers in the drawings.