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