GB2510324A

GB2510324A - Ducting systems

Info

Publication number: GB2510324A
Application number: GB1220484.8A
Authority: GB
Inventors: Kenneth James Dalgarno; Michael Ronald Dalgarno
Original assignee: MICHAEL DALGARNO
Current assignee: MICHAEL DALGARNO
Priority date: 2012-11-14
Filing date: 2012-11-14
Publication date: 2014-08-06
Anticipated expiration: 2032-11-14
Also published as: GB2510324B; GB201220484D0

Abstract

A duct for an air distribution system comprises a plurality of duct sections 1, 2 each comprising a hollow tubular element providing an air passage and having means to enable the plurality of duct sections to be joined together to form an air passage of desired length, wherein, prior to being joined together, each duct section is lined with an insulating lining material 8. The duct sections may be joined together by means of end flanges 5, 6 and a gasket 7 between the flanges. The insulating lining layer 8 of adjacent sections 1, 2 may abut to provide a continuous lining of the air passage or the ends 11 of the lining may be sealed with foil tape 12. The lining and/or the gasket may be formed of an expanded or foamed plastics material or a phenolic material and the insulating lining may be secured to the duct wall with a mastic adhesive 9.

Description

I

Ducting systems The present invention relates to ducting systems and particularly to a duct for an air distribution system Ducting systems for the distribution of veritiating or heating air are widely used in offices, warehouses, shops and factories-In many instaUations, it is a requirement for the ducts to be thermally insulated. Typically, this is done by first erecting the entire ducting system and when it is in place covering the outside of the ducting with a thermal insulating layer.

There are a number of disadvantages with this arrangement. Since the ducting is typically placed high off the ground, it is necessary to erect scaffolding for the workers installing the therma! installation, but there is still a significant risk of falls which creates a safety hazard. The productivity of workers working under these conditions is inevitably lower than if they were working at ground level. It frequently occurs also that there are difficulties in accessing certain parts of the ducting. where this is close to the roof of example. Furthermore, it is difficult to monitor and check the quality and the uniformity of the installation with the result that gaps may be formed in the installation which leads to cold spots and the risk of condensation forming in the ducts.

There are therefore a number of disadvantages with the existing system which risk compromising the integrity of the insulation and also make it very costly to install. The present invention seeks to provide a practical solution to these problems.

According to the present invention there is provided a duct for an air distribution system, including a dud section comprising a hollow tubular eiement providing an air passage and having means to enable a plurality of duct sections to be joined together to form an air passage of desired length, wherein, prior to being joined together, each duct section is lined with a thermal insulating lining material.

Preferably, a plurality of duct sections are joined together to form an air passage, the duct sections having end flanges through which adjacent duct sections are joined together, the insulating lining of adjacent sections abutting to provide a continuous lining of the air passage.

Advantageously, an insulaUng gasket is disposed between the adjoined flanges.

Preferably, the end faces of the insulating lining which abut when two sections are joined, are sealed with a foil tape or hardeast seal.

n a preferred embodiment, the lining material is secured to the duct by a mastic adhesive. n this case, an air gap may be formed between the inner surface of the duct and the insulating lining, the air gap at the ends of a ducts section being closed by mastic adhesive. Preferably, the insulating Uning material and/or the gasket is formed of an expanded or foamed plastics material such as.a phenolic resin based materiaL A preferred embodiment of the present invention wi now be described by way of example with reference to the accompanying drawings in which:-Figure 1 shows a sectional side view of two duct sections joined together, Figure 2 shows a sectional side view of an end of a duct section, and Figure 3 shows a perspective view of part of a duct section having a rectangular cross-section.

Referring now to Figure 1 there is shown a longitudinal cross-section through one wall of two duct sections 1. 2 which are of rectangular cross-section. Reference 3 shows the relationship of the duct housing 2 and air passage 3 extending through both duct sections 1, 2. The duct sections 1, 2 are farmed of sheet steel walls 4 and each have at their ends upstanding flanges 5, 6 by which adjacent duct sections can be secured together by bolts or rivets (not shown) passing through both flanges 5, 6. In this embodiment, a gasket 7 forms a joint seal of a foamed plastics or butyl material and is located between the flanges 5, 6 to provide thermal insulation. Each dud section 1, 2 is lined with a thermal insulating lining 8 of thermal insulating lining material comprising a foam or expanded synthetic plastics material such as a laminated phenolic based board.

The insulating lining 8 is secured to the inner face of the duct wall 4 by means of a mastic adhesive 9 which forms a small air gap between the lining material 8 and the inner surface of the duct wall 4. At the ends of the duct sections 1, 2, the air gap is closed by further mastic adhesive 10. To prevent the ends 11 of the insulating lining being damaged during transit or assembly, the ends 11 are sealed by a foil tape 12 or hardcast material to seal and protect the ends. When the ducting is used on externaI appUcations such as the outside of roofs, additional mastic materia! may be used on the outside. The external edge 13 of the flanges 5, 6 and the gasket 14 arc preferably dosed by a weather cap 15 clipped onto the outside periphery and sealed with a mastic adhesive. In an alternative form for interior use, a decorative cap may be used.

As shown more dearly in Figure 2 and 3, the lining material is in the form of insulation board 8 which lines the interior of the rectangular ducting 5, 6, the ends 11 of adjacent sheets abutting to ensure that there is no air gap. Figure 3 in particular Wustrates the air gap between the lining material and the inner surface of the duct wall 4 with the air gap being sealed by mastic adhesive. It can be seen in Figure 3 that the lining material 8 projects very slightly from the end of the duct section to ensure that no gap is formed between adjacent duct sections 1, 2 when they are secured together.

As can be seen from these embodiments, the present invention has the advantage that the duct insulation can be carried out in a factory controlled conditions which ensures accuracy of the insulation and greatly facilitates the monitoring and checking of the assembly. This results in enhanced thermal insulation. The fact that the installation is on the interior of the ducting reduces the risk of damage in transit and installation and also reduces the risk of damage being caused in use by birds and/or vermin, which reduces maintenance costs.

There is also a considerable saving in cost of installation since there is only one stage of installation rather than the known system of two, the first being the installation of the ducting and then a second team has to be used to install the insulation.

Although the embodiment illustrated is a rectangular cross-section duct, the present invention is equally applicable to circular or oval ducts. In the described embodiment; the lining material consists of boards which are secured to the interior of the duct by means of a mastic adhesive. Alternative methods of construction may be used, such as spraying a foamed plastics material onto the interior surface. Although described as being for an air distribution system, the term air should be construed broadly to include other gases such as carbon dioxide-enhanced air as used in horticulture, or gases in industrial processes.

Claims

Claims 1. A duct for an air distribution system, including a duct section comprising a hoflow tubular element providing an air passage and having means to enable a plurahty of duct sections to be joined together to form an air passage of desired length, wherein, prior to being joined together, each duct section is lined with a thermal insulating lining materIal.
2 A duct assembly comprising a plurality of duct sections as claimed in claim 1, joined together to form an air passage, the duct sections each having end flanges through which adjacent duct sections are joined together, insulating lining of adjacent sections abutting to provide a continuous lining of the air passage.
3. A duct assembly according to claim 2 wherein an insulating gasket is disposed between the adjoined flanges.
4. A duct as claimed in claim 1, 2 or 3, wherein the end faces of the insulating lining which abut when two sections are joined, are sealed with a foil tape or hardcast seal.
5. A duct as claimed in the any one of the preceding claims wherein the lining material is secured to the duct by a mastic adhesive.
6. A duct as claimed in claim 5 wherein an air gap is formed between the inner surface of the duct and the insulating lining, the air At the ends of a ducts section being closed by mastic adhesive.
7. A duct as claimed in any one of the preceding claims wherein the insulating lining material is formed of an expanded or foamed plastics material.
8. A duct as claimed in claim 3, or any claim dependent thereon, in which the gasket is formed of an expanded or foamed plastics material.
9. A duct at claimed in ciaim 7 or S wherein the piastics materlai is a phenohc based materia
10. A duct for an air distribution system, substantialiy as described herein with reference to and as Uustrated in the accompanying drawings.