Flameshield’s non-coated range of fire resistant ductwork is the ideal choice as a Smoke Extraction System.
By design a smoke extraction fan should be rated equal to the compartment walls or floor in stability, integrity and insulation criteria as set out in the standards EN 1366 Part 8 Flameshield’s extraction system exceeds expectations.
The test standard EN 1366 Part 1 (Duct A) identifies that the leakage of a duct should be within the criteria of the test standard. The test standard EN 1366 Part 8 requires that ducts MUST also have retained at least 90% of its original shape after being exposed to furnace gases and a tested solution with external insulation applied to the surface of the duct.
The latest Flameshield, non coated fire-rated system has now been certified by the LPCB (Loss Prevention Certification Board) as a fire-rated system which is rated for up to 2 hours stability and integrity with 2 hours insulation. The system has a 2 hour stability and integrity rating for all smoke extract systems.
Flameshield’s LPCB certification gives the end-user the added reassurance of a fire-rated system that is recognised by insurers.
Flameshield smoke exhaust ducts are proven to:
- Last for up to 120 minutes in terms of integrity and insulation (EI) for rectangular ducts and for both horizontal and vertical applications.
- Retain at least 90% of its cross sectional area both in the fire compartment as well as in adjacent compartments.
Flameshield Products can also offer its non-coated fireduct for smoke extract applications rated at 300 deg. C without the need for any additional coverings, should local authority building control be prepared to accept relaxed specification for low temperature smoke extract systems.
Flameshield low temperature test
Flameshield’s non-coated range of fire resistant ductwork has been assessed as being suitable for use as a smoke extract system. By design a smoke extract fan operates at significantly lower temperatures than those found in a fully developed fire. Therefore the internal duct temperatures are also significantly lower.
Low temperature installations must still however meet the stability and integrity criteria set out in the standards described in BS 476 Part 24.
Whilst the internal temperature of the duct might be lower than that described in ISO834:1975(E) Fire Resistance Time – Temperature Curve, the insulation failure criteria for a low temperature smoke extract system must comply with the requirements of BS 476 Part 24 i.e. the temperature rise on the external surface of the duct
- must not exceed an average rise of 140 deg. C plus ambient or
- must not exceed a maximum rise of 180 deg. C plus ambient.
Flameshield, under the auspices of BRE Global have carried out a low temperature test (BRE Test No. 259742), without any additional external insulation, to the performance standards described in BS 476 Part 24 of 300 deg. C for 3 hours and have fully satisfied the insulation criteria of this standard.
Flameshield therefore are able to offer its non-coated fire duct system for smoke extract applications rated at 300 deg. C without the need for any additional coverings.