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CEN Hazard Classification for Sprinklers and Water Mist. Dr. Maarit Tuomisaari Marioff Corporation Oy. EN 12845:2003 for sprinklers Hazard classification based on long-term experience Given hazard classification reflects the challenge to the
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CEN Hazard Classificationfor Sprinklers and Water Mist Dr. Maarit Tuomisaari Marioff Corporation Oy IFSA 2008 / 24 - 25 June, 2008
EN 12845:2003 for sprinklers • Hazard classification based on long-term experience • Given hazard classification reflects the challenge to the • 2-dimensional wetting of traditional water sprays. • prCEN/TS 14972 for water mist systems • No hazard classification specified. • The sprinkler classification does not necessarily reflect the • challenge to water mist systems that do not rely only on • wetting but also on 3-dimensional inerting, cooling of gases • and blocking of radiant heat. IFSA 2008 / 24 - 25 June, 2008
EN 12845:2003 for sprinklers Prescriptive requirements OH1 OH2 OH3 OH4 Design density (mm/min) 5 5 5 5 Area of operation (m2) 72 144 216 360 Nominal number of sprinklers 6 12 18 30 prCEN/TS 14972 for water mist systems Performance-based requirements OH1 OH2 OH3 OH4 Design density ”equivalent” to 5 mm/min Area of operation (m2) 72 144 216 360 Nominal number of sprinklers depends on the coverage area (1 (1 (1 not a requirement but common practice IFSA 2008 / 24 - 25 June, 2008
EN 12845:2003 OH1 Occupancies prCEN/TS 14972 IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 OH1 Occupancies / offices • Reference sprinkler: • Pendent spray sprinkler • Special Response • Nominal K factor 80 • Temperature rating 68 ºC • Fire tests: • Ignition under one sprinkler • Ignition between four sprinklers • Repetition of the worse one • Criteria to be defined: • Fire damage • Temperatures IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 OH1 Occupancies / offices • Water Mist sprinkler: • To be defined in the tests • Fire tests: • Ignition under one sprinkler • Ignition between four sprinklers • Repetition of the worse one • Criteria: • Fire damage as per REF • Temperatures as per REF IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 OH1 Occupancies / offices VdS approval coverage with an extensive number of additional fire tests according to FM, IMO and VdS test procedures • Design criteria System A System B • - water density < 0.6 mm/min 1.5 mm/min • coverage per sprinkler 12.25 m2 25 m2 IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 OH1 Occupancies / offices • Conclusions: • For OH1 type hazards the number of • sprinklers activating is the same for both • the sprinkler and referred water mist • systems. • Number of sprinklers is a more relevant • design parameter than a fixed operation • area. IFSA 2008 / 24 - 25 June, 2008
EN 12845:2003 OH3 Occupancies prCEN/TS 14972 - proposal IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 - proposal OH3 Occupancies IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 OH3 Occupancies VdS approval coverage with REF system operated at 8 mm/min instead of 5 mm/min • Design criteria • - water density 3.8 mm/min • coverage per sprinkler 9 m2 IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 – proposal OH3 Occupancies • Conclusions: • For OH3 type hazards the number • of sprinklers activating is different • for the sprinkler and referred water • mist system. • Number of sprinklers is a more • relevant design parameter than a • fixed operation area. IFSA 2008 / 24 - 25 June, 2008
prCEN/TS 14972 – proposal OH3 Occupancies Aspect that is not taken into account at all: REF17 700 LITRES WATER WATER MIST4100 LITRES WATER IFSA 2008 / 24 - 25 June, 2008
Study on operation areas together with Dr.Jukka Vaari, VTT, Finland 2 MW concealed pallet pile2 MW open pool4 m & 2.5 m ceiling heights IFSA 2008 / 24 - 25 June, 2008
2 MW concealed pallet pile / 2.5 m ceiling height REF WATER MIST Number of sprinklers activating in the tests REF (5 mm/min) Water Mist System (OH1) 4 – 15 / 184 m2 1 – 4 / 100 m2 IFSA 2008 / 24 - 25 June, 2008
61.25 m2 - 3 mm/min 80 m2 - 2.3 mm/min 100 m2 - 1.5 mm/min IFSA 2008 / 24 - 25 June, 2008
SUMMARY • Prescriptive requirements of EN 12845 may well be justified • based on the long-term experience with sprinklers. • Prescriptive dimensioning of EN 12845 based on fixed • prescripitive hazard classification should not be mixed with • the performance based design of prCEN/TS 14972 • Number of nozzles is a more relevant design parameter than a fixed area • Relevant design fires – instead of fixed hazard classification – to be developed for defining the design number of nozzles • Experience and dedicated research will lead to performance-based ”hazard classification”, i.e. correspondence between each design fire and different hazard types. IFSA 2008 / 24 - 25 June, 2008
THANK YOU ! IFSA 2008 / 24 - 25 June, 2008