1	Water Mist Fire Suppression Systems Carmen Shafer, CSP, CHST Grunley-Walsh, LLC
2	The Fire Triangle
3	Traditional Sprinkler System Uses water to wet the surrounding areas, preventing conflagration and allowing occupants necessary time to escape Designed to control or suppress but not necessarily extinguish fires Results in large amounts of water and smoke damage
4	Water Mist System Uses a pump or compressed gas to force water through small orifices creating a smaller droplet size Tends to be very successful at extinguishing incipient fires High Pressure (Class I) system developed in Finland by Marioff Corporation Originally designed for shipboard use – to control engine fires Use has expanded to other industries and areas of use
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6	High Pressure Water Mist Extinguishes Fire by: Cooling/Heat Absorption Radiant Heat Blocking Oxygen Depletion/Local Inerting
7	Cooling/Heat Absorption In vaporization, water can absorb over 2MJ/kg – superior to any other suppression material on the market (Marioff) Heat energy from gases and vapors are removed quickly in this process
8	Radiant Heat Blocking As the mist expands, it creates a cool “wall” that blocks radiant heat and prevents general conflagration Mist “wall” also creates a cooler environment, allowing fire fighting personnel to come closer to the source of the fire with less danger
9	Oxygen Depletion/Local Inerting Vaporization of the water mist locally inerts the atmosphere as the volume of the water expands over 1700 times (Marioff) Mist from the system penetrates the fire and locally inerts this area
10	Benefits of the Water Mist System Suppresses the fire quickly and effectively Uses 70% to 90% less water than sprinkler Little or no water damage Less smoke damage – system can be combined with scrubbers to eliminate or greatly reduce smoke particles Is not harmful to life or the environment Uses less material in construction Can improve aesthetics – smaller pipes, smaller heads placed farther apart
11	Water Mist Systems Test fires extinguished with 1-5 gallons of water Many test fires suppressed in less than a minute Fire scenario tests extinguished in 5 minutes. (Artim)
12	Disadvantages of the Water Mist Systems Requires more engineering and design time and resources than traditional systems As this is not a common system in the US at this point; regulations, certification requirements, etc. take a lot of time and effort. Installation requires high skill level More expensive than a sprinkler system (see above) More expensive in small applications than clean agents Some sources say it will not work in certain applications (other sources disagree)
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14	System Components Depends on Application Can use domestic water, sea water or water in tanks and canisters Can use compressed gas mixed at the source (single pipe) or at the head (dual pipe) or use a pump Wet or dry pipe applications Pipe diameter ranges from ½ to 1 ½ inches in diameter (²/₃ of the piping is ½”)
15	NFPA 750 Requirements Water supply shall be taken from a source equivalent in quality to a potable source with respect to particulate and dissolved solids, or from a source of natural seawater To minimize corrosion, all piping shall be stainless steel or copper
16	System Types Low pressure, twin fluid, gas driven (Securiplex) Intermediate pressure, single fluid, gas driven (Chemetron, Fike) High pressure, single fluid, gas driven (Marioff, Fogtec, others ...) High or Low pressure, single fluid, pumped (Marioff, Fogtec, UniFog, Aquamist, … ) Decaying pressure, hybrid gas-water (Marioff) Cycled discharge VS continuous discharge (Securiplex, Fike, Chemetron, others … )
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18	Current Uses of Water Mist Systems Shipboard Applications IT Rooms Historical Buildings & Museums Hotels and Residential Construction Train Tunnels, Parking Garages, etc.
19	Shipboard Application Small Engine Fire
20	Open Space Fire
21	IT Rooms Viable alternative to CO₂ and Halon Problem of smoke damage is controlled or eliminated by the scrubbing system – Also reduces HCl concentrations by dilution High pressure water mist system can activate immediately, CO₂ may take up to 20 minutes to activate. (ORR) Research shows that nozzles are best situated inside the system and in the sub-floor rather than at the ceiling
22	Historical Buildings & Museums
23	Historical Buildings & Museums
24	National Gallery of Art National Gallery of Art West Building Renovations (HSMM/HAI) High Pressure (1,600 psig) water mist system used in moderate to high fire load areas in combination with air washers Motorized smoke dampers located above artwork exhaust smoke from the galleries HVAC system uses air cleaners to maintain humidity and remove harmful particles from the air
25	Hotels and Residential Application Marriott Hotels using Class I water mist systems for general fire protection In Great Britain, water mist systems are used in condos and other residences Water Mist systems widely used in Canada, Great Britain and Europe.
26	Transportation Metro Tunnels in Madrid, Spain (Marioff) and Budapest (Fogtec) Parking Garages Airplanes (being studied)
27	Car Deck Fire
28	Kitchens - Research CONSTRUCTION INNOVATION Volume 4, Number 3, Spring/Summer 1999 “Water-mist fire-suppression systems offer excellent protection for commercial cooking areas” “Almost 50% of all accidental fires in hotels, restaurants and fast-food outlets start in the kitchen and the majority of these involve cooking oil or fat. These fires are difficult to extinguish because they burn at a high temperature and re-ignite easily. Without effective suppression, cooking-oil fires can cause serious damage to property and loss of life.”
29	Test – Kitchen Oil Fire Oil auto-ignited at 365° to 370° Allowed to burn for 2 minutes Low pressure water mist system would not suppress the fire, but the high pressure systems were successful Initial flare up occurred at initiation When system quit shortly after suppression, the oil would reignite at 300° The chemical makeup of the oil changed during the free-burn and suppression periods
30	Tests – Fryer Oil Fire
31	Mobile Fire Fighting Fogtec and Danfoss each marketing a mobile water mist fire extinguishing system
32	Questions???
33	Resources Artim, Nick. “An Introduction to Automatic Fire Sprinklers, Part 1.” WAAC Newsletter, Vol. 16, No. 3, Sept. 1994. Artim, Nick. “An Update on Micromist Fire Extinguishment Systems.” WAAC Newsletter, Vol. 17, No. 3, Sept. 1994. Beall, Kellie Ann ed. Thirteenth Meeting of the UJNR Panel on Fire Research and Safety, March 13-20, 1996 Volume 2. Building and Fire Research Laboratory, NIST. Gaithersburg, MD. Building Research Establishment Ltd. (bre). “Fire Suppression in Buildings Using Water Mist, Fog or Other Similar Systems. Project Report no. 213293v3. 2005. Chemtron Fire Systems Water Mist Brochure Coastal Fire Sprinkler Co. Ultra Fog Water Mist Systems. Danfoss A/S Website/Brochure. “Nessie High Pressure Water Mist Components for Fire Fighting. Fike Corporation web page http://www.fike.com FOGTEC web page http://www.fogtec-international.com Gagnon, Robert M. P.E. “Water Mist Fire Supression Systems Theory and Application.” NAFED Website http://www.nafed.org/resources/library/wmist.cfm. Gardner, Thomas W and Fisher, John E. III. “Testing and Inspection Spell Success for Life-Safety Systems. www.facilitiesnet.com.
34	Resources Gordin, Stefan. “High Speed Water Mist Helps Minimize Damage from Fire.” Engineer Live!, September 13, 2005. Liu, Dr. Zhigang. “Fire Risk Management.” Construction Innovation. Vol. 3, No. 2, Winter 1998. Liu, Dr. Zhigang. “Water-mist Fire-suppression Systems Offer Excellent Protection for Commercial Cooking Areas.” Construction Innovation. Vol. 4, No. 3, Spring/Summer 1999. Marioff Corporateion Oy website and brochures. http://www.hi-fog.com. NASA Glen Research Center. “Water Mist Fire-suppression Experiment (Mist) Studying Fire in the Sky.” February 2002. http://www.microgravity.grc.nasa.gov/combustion/ Nelson, Michael. “Fire Suppression Systems in Historic Places f Worship.” http://www.sacredplaces.org. October 1998. “New Technologies Demonstrate Ability to Defeat Aircraft Fires.” Air Safety Week. June 26, 2000. NFPA 750 ORR Protection Systems – “A Morning with the Experts Seminar Series – NFPA and EPA Drive Sweeping Fire Code Changes!” de Vires, Holger Ph.D. “Mining for Answers.” Primedia Business Magazines and Media. January 1, 2002 Voutilainen, Heikki. “Advances in Fire Protection of Machinery Spaces.” March 2005. http://www.safan.com. Witt, Calvin L. P.E. “Timeless Art, Timely Engineering.” May 2005.