GB2073837A

GB2073837A - Support and Coupling Assemblies for Ducting

Info

Publication number: GB2073837A
Application number: GB8111595A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-04-11
Filing date: 1981-04-13
Publication date: 1981-10-21

Abstract

The invention relates to a coupling assembly (10) for connecting together two lengths (11, 12) of air ducting. The assembly comprises a pair of concentric sleeves (13, 14) the innermost sleeve (13) being attached to adjacent ends (11a, 12a) of the two lengths of ducting and the outermost sleeve (14) being adapted for connecting to support means (17). A load bearing heat and/or noise insulating material (18) is located in the space between the sleeves. <IMAGE>

Description

SPECIFICATION Support and Coupling Assemblies for Ducting This invention relates to the supporting and coupling of lengths of ducting such as air ducting for air conditioning systems in buildings.

In ducting which transports conditioned air, that is air which has been heated or chilled, it is desirable to insulate the ducting ;n order to minimise energy losses and in the case of chilled air to avoid condensation forming on the metal duct.

It is further desirable to minimise vibratory noise transmitted from the ducting to the building in which the ducting is installed since this has the effect of increasing the noise levels in the building.

The support means and coupling arrangements by which such ducting is installed therefore should be chosen to avoid loss of thermal energy by conduction, to reduce vibratory noise levels in the building in which the ducting is installed and to avoid condensation. The latter effect is produced by "sweating" which occurs when support members are in contact with the cold metal of ducting which conveys refrigerated air.

Such condensation causes corrosion and moreover condensate can drip on to and stain expensive false ceilings behind which air conditioning ducting often is installed.

One aspect of the present invention provides a coupling assembly for connecting together two lengths of air ducting, which assembly comprises a pair of spaced substantially concentric coupling elements, one of the coupling elements being attached to adjacent ends of the two lengths of ducting, and the other coupling element being adapted for connection to support means, wherein a load bearing heat and/or noise insulating material is located in the space provided between the coupling elements.

According to a feature of this aspect of the invention said one coupling element is of similar cross section to that of the lengths of ducting and may comprise an inner sleeve surrounding and connecting together adjacent portions of the two lengths of ducting.

According to a further feature of this aspect of the invention said other coupling element may comprise an outer sleeve or similar cross section to that of the lengths of ducting. Preferably, the outer sleeve is spaced from the inner sleeve such that the external surface of the outer sleeve lies substantially flush with a layer of insulating material bounding the lengths of ducting. The layer of insulating material bounding the lengths of ducting may extend into the space between the outer and inner sleeves. Preferably, the axial length of the outer sleeve is less than that of the inner sleeve and the axial length of the load bearing insulating material is less than that of the outer sleeve.

According to a still further feature of this aspect of the invention the loading bearing insulating material may comprise a heavy density cork or a composite rubberised cork material. In some constructions the load bearing material may comprise a series of spaced pads located between the outer and inner sleeves. In other constructions the load bearing material may comprise an annular element located between the inner and outer sleeves.

The ducting may be supported by drop rods secured to the outer sleeve. Where this feature is adopted the drop rods are secured at their lower ends to lugs or brackets attached to the outer sleeve. Alternatively, the ducting may be supported on the outer sleeve. Where this feature is adopted the outer sleeve may be set down on angle or channel support members.

Preferably the lengths of ducting and the inner and outer sleeves are all of rectangualr cross section.

Another aspect of the present invention provides a support assembly for air ducting which assembly comprises a pair of spaced substantially concentric sleeve members one of the sleeve members having a length of the ducting extending therethrough and the other of the sleeve members being connected to support means through which the ducting load is transferred and wherein a load bearing heat and/or noise insulating material is located in the space provided between the sleeves.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:~ Figure 1 is a longitudinal cross section through an air ducting coupling assembly, and Figure 2 is a transverse cross section through the air ducting.

Referring to the drawings there is shown part of an air conditioning ducting system 10 for a building and comprising two lengths of rectangular cross section ducting 1 1, 12 respectively. End portions 1 1 a, 1 2a of the lengths of ducting 1 1, 12 are received in spaced coaxial relationship within a closely surrounding sleeve 13 which also is of rectangular cross section but of somewhat larger dimensions than the lengths of ducting. The sleeve 13 is connected to both lengths of ducting 1 1, 12 by riveting or although of course other suitable connecting means may be employed. Thus, the sleeve 13 provides a continuous bridge between the adjacent ends 1 1 a, 1 2a of the lengths of ducting. It is envisaged that the adjacent ends of ducting may be located closer to one another and could be in abutment.

The coupling assembly further comprises an outer sleeve 14 also of rectangular cross section which is concentric with and radially spaced from the inner sleeve 13. This outer sleeve is of shorter length than and axially centred around the inner sleeve. The ducting system 10 may be installed within the building support means, comprising a number of spaced drop rods 15 embedded at one of their ends in a concrete ceiling of the building and attached at their opposite ends to opposed sides of the ducting and secured thereto by means of angled brackets 16 (Figure 2). In this construction the angle brackets are carried by the outer sleeve 14.

Alternatively, the ducting system 10 may be installed within the building by support means comprising a series of channel support element 17 (Figure 1). In this construction the outer sleeve is set down on the element 17 so that the load exerted by the ducting is transferred to the support elements.

In order to minimise energy losses from transfer of thermal energy from conditioned air flowing through the ducting and to minimise vibratory noise transmitted to the building from the ducting it is desirable to insulate appropriate components of the ducting system. Such insulation comprises a layer 18 of general thermal/noise insulating material, for example glass or mineral fibre material or board which envelopes the lengths of ducting 11, 12. More particularly, further insulating material 19 is located at the support locations of the ducting system between the inner and outer sleeves 13, 14. Such insulating material 19 should be provided by a load bearing material which also has high thermal efficiency and the ability to absorb vibratory noise over a wide range of frequency registers.One suitable insulating material having such characteristics is a heavy density cork. However, known cork/rubber composite material is preferable.

The insulating material 19 located between sleeves 13. 14 respectively may comprise a series of pads or blocks or may be a continuous annular component. In either case it is preferable to fabricate the pads or annular component with a shorter axial length than that of the outer sleeve 14. In so doing, the adjacent portions of the general insulating material 18 can be received within the space defined between the inner and outer sleeves 13, 14 as shown in Figure 1. It also is preferable to have the external surface of the outer sleeve 14 lying flush with the outer surface of the layer of general insulation 1 8. This feature provides continuity of the outer surfaces for application of vapour sealing and fire retarding finishes which normally are required in such systems.

The insulating material 19 thus isolates the ducting from the support means for the system.

This is desirable not only from the standpoint of minimising the transfer of vibratory noise from the ducting to the building in which it is installed but also to minimise thermal energy losses and "sweating" resulting in condensation and subsequent corrosion.

The double sleeve insulated coupling assembly described above may be utilised merely as a support assembly without functioning to couple together adjacent lengths of ducting. In this case the inner sleeve 13 would be located around a continuous length of ducting but in other respects the assembly would be as previously described.

It is envisaged that the ducting and/or sleeves may be other than rectangular in cross section, for example, the invention is equally applicable for ducting of round or oval cross section.

Claims

1. A coupling assembly for connecting together two lengths of air ducting, which assembly comprises a pair of spaced, substantially concentric coupling elements, one of the coupling elements being attached to adjacent ends of the two lengths of ducting, and the other coupling element being adapted for connection to support means, wherein a load bearing heat and/or noise insulating material is located in the space provided between the coupling elements.

2. A coupling assembly as claimed in claim 1 wherein said one coupling element is of similar cross section to that of the lengths of ducting and comprises an inner sleeve surrounding and connecting together adjacent portions of the two lengths of ducting.

3. A coupling assembly as claimed in claim 2 wherein said other coupling element comprises an outer sleeve of similar cross section to that of the lengths of ducting.

4. A coupling assembly as claimed in claim 3 wherein the outer sleeve is spaced from the inner sleeve such that the external surface of the outer sleeve lies substantially flush with a layer of insulating material bounding the lengths of ducting.

5. A coupling assembly as claimed in claim 4 wherein the layer of insulating material bounding the lengths of ducting may extend into the space between the outer and inner sleeves.

6. A coupling assembly as claimed in any of claims 3 to 5 wherein the axial length of the outer sleeve is less than that of the inner sleeve and the axial length of the load bearing insulating material is less than that of the outer sleeve.

7. A coupling assembly as claimed in any of claims 3 to 6 the loading bearing insulating material comprises a heavy density cork or a composite rubberised cork material.

8. A coupling assembly as claimed in claim 7 wherein the load bearing material comprises a series of spaced pads located between the outer and inner sleeves.

9. A coupling assembly as claimed in claim 7 wherein the load bearing material comprises an annular element located between the inner and outer sleeves.

10. A coupling assembly as claimed in any of claims 3 to 9 wherein the ducting is supported by drop rods secured to the outer sleeve.

11. A coupling assembly as claimed in claim 10 wherein the drop rods are secured at their lower ends to lugs or brackets attached to the outer sleeve.

12. A coupling assembly as claimed in claim 10 wherein the ducting is supported on the outer sleeve.

13. A coupling assembly as claimed in claim 11 wherein the outer sleeve is set down on angle or channel support members.

14. A coupling assembly as claimed in any of claims 3 to 13 wherein the lengths of ducting and the inner and outer sleeves are all of rectangular cross section.

1 5. A support assembly for air ducting which assembly comprises a pair of spaced substantially concentric sleeve members, one of the sleeve members having a length of the ducting extending therethrough and the other of the sleeve members being connected to support means through which the ducting load is transferred and wherein a load bearing heat and-or noise insulating material is located in the space provided between the sleeves.