BS EN 1366-8:2004 Fire Resistant tests for Smoke Extraction Ducts (Multi compartments)

This test is applicable to fire resisting Ducts that have already passed the appropriate test to BS EN 1366-1 where the fire outside (Duct A) has been tested to a differential pressure of 500 Pa.

The Smoke Extract Duct also needs to be tested as fire inside (Duct C).

Basement smoke extract system

Performance Criteria

Insulation

Test results from BS EN 1366-1, this test is deemed to demonstrate the insulation performance of the duct.

Integrity

Integrity failure occurs if any of the following take place.

  • A cotton pad is ignited.
  • Sustained flaming of a duration of at least 10 seconds appears on the unexposed face of the test specimen outside the furnace.
  • Increased leakage flow rate through the Duct section outside the furnace.

Reduction in cross section

The internal dimensions must not decrease by more than 10% during the test (both inside & outside the furnace).

Stability

The duct inside the furnace must maintain its smoke extraction and fire resistance function without collapsing.

Direct Field of application (Ducts up to 1250mm x 1000mm deep)

The requirements for direct field of application for Smoke Extract Ducts tested to BS EN 1366-1 apply together with the following:

  • A Duct type C (fire Inside) test 1000mm x 250mm rectangular and 560mm circular is carried out allowing all dimensions of the Duct up to the size tested plus the size increase as follows:
    • Duct C +250mm wide +750mm high (for rectangular Ducting) and +440mm (for circular ducting). Hence tested duct size is 1000mm x 250mm therefore suitable for Duct sizes up to 1200mm x 1000mm.
  • The test results on the Duct are applicable to the following under and over pressures depending on the negative pressure used in the test:
    1. Tested to a static pressure at ambient of -500 Pa and then fire tested whilst under the equivalent pressure in a fire of at -150 Pa.
    2. Tested to a static pressure at ambient of -1000 Pa and then fire tested whilst under the equivalent pressure in a fire of -300 Pa.
    3. Tested to a static pressure at ambient of -1500 Pa and then fire tested whilst under the equivalent pressure in a fire of -500 Pa.

All smoke systems are classified as suitable for +500 Pa although the construction of the Duct may be greater than that in HVCA DW144 for higher positive pressures.