Ducting - CDA CCA51 Installation, Use And Maintenance Manual

3. Connect securely the exhaust pipe to the duct adapter and locate
on the extractor. We recommend the use of 120mm (5") ducting,
although 100mm can be used with the use of a 120-100mm
converter; Note that this will affect performance and potentially
increase noise.

Ducting

The ducting used should be rigid pipe of a constant diameter and
must be manufactured from fire retardant material, produced to BS
476 or DIN 4102-B1.
Wherever possible utilise rigid circular pipe which has a smooth
interior, rather than the expanding concertina type ducting. The
lengths of ducting with minimal effect on performance are as follows:
• 4 metres with 1 x 90° bend.
• 3 metres with 2 x 90° bends.
• 2 metres with 3 x 90° bends.
Please note: Ducting components and ducting kits are optional
accessories and have to be ordered, they are not automatically
supplied with the hood. Use of ducting of a lesser diameter than
the flanges supplied will affect performance and increase the noise
produced by the extractor. Longer ducting can be used but the
performance of the extractor will likely be reduced.
Note that the ducting should be secured and sealed to the vent
outlet using appropriate jubilee clips or securing means.
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