Ventilation and Smoke Extraction Ducts

The relative complexity of any ductwork system which is passing through different fire compartments and the relevance of the system’s function in ambient and fire conditions can make the selection of a suitable ductwork system difficult.

To determine the fire resistance of ducts (without the aid of fire dampers) passing through or between compartments, the system should normally be tested or assessed in accordance with BS 476: Part 24: 1987 or equivalent local legislation. 

Factors for consideration when determining the correct specification to ensure ducts will provide the required fire performance include:

• Required fire exposure
• Required fire performance
• Supporting structure
• Hanger support
• Steel ductwork
• Penetrations through walls and floors
• Ductwork functions
• Acoustic performance
• Thermal insulation
• Water tolerance
• Strength and appearance
• Access requirements (hatches) for inspection