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Ventilation Ducting  | Rectangular Ductwork |  Offsets

Ductwork offsets are a regular part of a ductwork sytem. They are often used to avoid obstacles, either structural, such as beams, columns etc. or to avoid other mechanical services such as pipework or electrical installations. They may be used to realign a duct run to enable it to pass through a confined space, or to make a final connection with HVAC equipment. They are sometimes manufactured as an 'extra' i.e. a variation to the original ductwork design due to an unforseeen obstruction at the job site, or an oversight during the design process.

Ductwork specification DW144 stipulates that the slope angle should be no more than 30°. For this reason, the amount of 'set over' tends to be quite small. In order to conform to the 30° rule, the larger the offset distance is, the longer the total length of the duct piece will be. A large offset distance may mean that the piece needs to be so long that it becomes impractical to manufacture as one part. Instead separate bends and straight sections are used to achieve the same result. All the offsets we supply are manufactured in accordance with DW/144 unless requested otherwise. This means that the overall length of the offset piece will be determined by us - unless an alternative length is requested at the time of ordering.

Manufactured from 0.7mm galvanised mild steel.

Click on a size below that represents the width of the offset required as depicted in the drawing to the right. Depth and the 'set over' can be selected on the following pages.

Note that rectangular ductwork is made to order. Please therefore take manufacturing time into account when scheduling your project.


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