Mechanical ventilation with heat recovery

8.3.7Ductwork

Ductwork design and the materials used should be suitable for the intended purpose and not adversely affect the performance of the building.

Ductwork should:

  • provide satisfactory performance for the life of the system
  • be routed as directly as practicable
  • be of a rigid or semi-rigid material suitable for use in MVHR systems
  • be fixed in accordance with the manufacturer’s recommendations.

Bends, connections and junctions should be formed using proprietary components that are part of the ductwork system.

Flexible ducting should:

  • only be located adjacent to fan units or air valves
  • not be more than 300mm in length
  • not be used to form bends.

Where ductwork routes require alterations to structural elements, these should be in accordance with the manufacturer’s recommendations or in accordance with Technical Requirement R5.