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FIRE PROTECTION SYSTEMS

2. Fire Protection System Design Strategy. Comprehensive StrategyPrevent fires from starting in the first placeEducationAdministrative proceduresSignageInspectionsFire safety programFire alarm and detection systemsDetect fires early to initiate quick evacuationDesign safe egress from buildi

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FIRE PROTECTION SYSTEMS

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    1. 1 FIRE PROTECTION SYSTEMS

    2. 2 Fire Protection System Design Strategy Comprehensive Strategy Prevent fires from starting in the first place Education Administrative procedures Signage Inspections Fire safety program Fire alarm and detection systems Detect fires early to initiate quick evacuation Design safe egress from building Exits, Stairwells, Corridors Emergency lighting and ventilation

    3. 3 Design Strategies (cont’d) Fire suppression systems Sprinkler Standpipe and Hose Chemical Smoke Control systems Remove smoke from exits Provide fleeing occupants with breathable air

    4. 4 Design Strategies (cont’d) Compartmentalization Break a building into small compartments to contain fire and smoke Fire Separation Fire rated wall, floor, ceiling assemblies that impede the spread of fire Use of non-combustible materials Use of low flame spread and smoke developed finish material

    5. 5 Flame Spread ASTM E84 – Test Method for Surface-Burning Characteristics of Building Materials (Steiner tunnel test). Rates surface-burning characteristics of building materials and interior finishes, and provides data on smoke density. Flame spread classifications: Class A: 0-25 Class B: 26-75 Class C: 76-200 Local building codes generally restrict use of materials in different occupancies based upon flame spread and smoke developed ratings. For example, NYSED Manual of Planning Standards requires finishes in corridors, passageways, stairways to be Class A.

    6. 6 Sources of Ignition Spontaneous Combustion Electrical Sources Arcing Lightning Mechanical Friction Other Intentional (arson) Cigarettes

    7. 7 Fire Issues Products of combustion – CO, CO2, other gases Fire quickly consumes oxygen Lack of oxygen Rapid deterioration of human capabilities Muscle control Thinking, consciousness, etc. Poor visibility

    8. 8 Fire Issues (cont’d) Vertical shafts promote spread of smoke, heat Elevators Escalators Atriums HVAC systems can spread smoke Windowless buildings – prevent entry by firefighters Interior finishes – can spread fire, give off smoke High rise buildings (g.t. six stories) – complicate firefighting, rescue

    9. 9 Fire Alarm and Detection Systems Design Standards Fire Code of NYS – defines minimum standards where fire alarm and detection system is required, general design requirements NFPA 72 – National Fire Alarm Code – defines specific design standards Functions of a fire alarm and detection system: Initiate alarm Manually Automatically Notify occupants Audible alarms Visual alarms

    10. 10 Functions (cont’d) Automatically signal fire department or central station Recall elevators Supervise special systems: Fire pump operation, power availability Sprinkler system status Unlock doors Automatically close doors that are part of fire separations Automatically release smoke relief hatches Control operation of HVAC supply and exhaust fans Total shut down Special smoke management systems

    11. 11 Typical Fire Alarm System

    12. 12 Fire Alarm Control Panel

    13. 13 Fire Alarm Systems (cont’d) Types Conventional (off/on “dumb” devices) Addressable Analog Digital Equipment Manual Fire Alarm Boxes (Pull Stations) Mounting – not less than 3.5 and not more than 4.5 ft above floor level (ADA requires maximum 48” high forward reach) Spacing: At exit doorways within 5’ of each exit doorway on each floor; on both sides of opening 40 feet and wider, and within 5 feet each side Additional boxes such that distance of travel to any box less than 200 feet on same floor

    14. 14 Manual Alarm Station at Exit

    15. 15 Fire Alarm Systems (cont’d) Heat Detectors Applications Where smoke is ordinarily present Top of elevator shafts where sprinklers are present Types Fixed Combination fixed/rate of rise Location On ceiling not less than 4” from sidewall, or on sidewall between 4” and 12” of ceiling

    16. 16 Fixed Type Heat Detector

    17. 17 Fire Alarm Systems (Cont’d) Heat Detectors (cont’d) Typical Spacing Fixed: 15’x15’ Combination fixed/rate of rise: 50’x50’ All points on ceiling within 0.7 x listed spacing Special considerations – beam construction, sloped ceilings – refer to NFPA 72 for spacing requirements.

    18. 18 Smoke From Cooking Appliances Can Set Off Smoke Detector

    19. 19 Stages of a Fire Incipient – invisible combustion gases, without smoke or flame, no appreciable heat release Smoldering – heat still absent, combustion gases now visible as smoke Flame – actual fire is produced, a column of gases made luminous by intense heat Heat – follows concurrently or just after flame stage – tremendous amounts of heat released

    20. 20 Smoke Detectors Types Spot Beam Design: Ionization Photoelectric Spot Detector Accessories Integral alarm Typical use – motels and similar sleeping spaces

    21. 21 Photoelectric Spot Smoke Detector with Integral Alarm Photoelectric detectors operate using principle of “smoke obscuration” Smoke interposed in light beam between small emitter and detector Decreased light intensity at detector causes alarm to sound Device in photo also includes integral alarm – used in motels and similar sleeping spaces.

    22. 22 Principle of Operation – Ionization Detector

    23. 23 Smoke Detectors (cont’d) Applications Spot detectors For general fire detection Close doors, operate smoke dampers Beam detectors High ceilings where spot detectors impractical Location On ceiling not less than 4” from sidewall, or on sidewall between 4” and 12” of ceiling

    24. 24 Smoke Detector Mounted on Wall

    25. 25 Smoke Detectors (cont’d) Typical Spacing (spot) 30’x30’ All points on ceiling within 0.7 x listed spacing g.t. 3’-0” from HVAC diffusers, supply grilles Special considerations – beam construction, sloped ceilings – refer to NFPA 72 for spacing requirements.

    26. 26 Typical “Listed” Smoke Detector Spacing

    27. 27 Incorrect Application of Smoke Detector Area covered = 60’ x 15’ = 900 s.f. Distance to corner exceeds 0.7 x listed spacing (0.7 x 30 = 21’) Two smoke detectors would be required for this room.

    28. 28 Beam Smoke Detector Smoke rising to ceiling will obscure light beam. Receiver will detect change in beam intensity and cause alarm to sound. Often used in atrium spaces, high “cathedral ceilings”, similar spaces.

    29. 29 Notification Appliances Audible Refer to NFPA 72 for sound pressure levels Mounting Wall – top not less than 90” a.f.f., not less than 6” below ceiling (where ceiling heights allow) If combined with visual appliances, entire lens of visual appliance not less than 80” nor greater than 96” a.f.f. Spacing Such that they can be heard throughout building Refer to NFPA 72 for specific requirements

    30. 30 Audible Visual Device in School Cafeteria

    31. 31 Audible Visual Fire Alarm Appliance

    32. 32 Notification Appliances (cont’d) Visual Appliances Location Wall mounted – entire lens 80” -96” a.f.f. Ceiling mounted permitted when device is specifically listed for this application. Spacing Refer to NFPA 72 When two or more in same field of view, must be synchronized (can be harmful to persons with epilepsy)

    33. 33 Remote Annunciator Panel at School 80 An annunciator panel displays at remote entries and other locations the zone or device that is in alarm – generally located at main entries.

    34. 34 FIRE SUPPRESSION SYSTEMS

    35. 35 Types of Fire Suppression Systems Standpipe and Hose Systems A reliable water supply, piping, hose connections to permit manual extinguishing of a fire. Sprinkler Systems A reliable water supply, piping, sprinklers, to permit automatic extinguishing of a fire. Chemical Extinguishing Systems Both manual and automatic systems Use a chemical extinguishing agent where water is not effective, or cannot be used.

    36. 36 Standpipe and Hose Systems Classification: Class I – 2-1/2” hose connections for firefighter’s use, 100 psi at uppermost hose connection. Class II – 1-1/2” hose connections for occupant use, 100 psi at uppermost hose connection. Class III – 2-1/2” and 1-1/2” hose connections for both firefighter’s and occupant use.

    37. 37 Diagram of a Typical Standpipe System

    38. 38 Standpipe Hose Valve at Intermediate Stairwell Landing

    39. 39 Typical Backflow Preventer for Fire Protection Service A backflow preventer prevents water contained in building piping systems from flowing back into the community water main. Water piping in buildings may contain foul and/or hazardous materials.

    40. 40 Classification (cont’d) Type I and III standpipes are the most common. Design Standard NFPA 14 Standard for the Installation of Standpipe, Private Hydrant, and Hose Systems. Current edition is 2003 As of 2004, NYS Building Code adopts the 2000 edition.

    41. 41 Combined Systems A combined system is a standpipe that also supplies automatic sprinklers on each floor. Combined systems were first permitted by NFPA in 1976 to encourage owners of high rise buildings that already had standpipes to install sprinkler systems. A sprinkler crossmain is connected to the standpipe at each floor. A typical connection detail is contained in NFPA 14 Figure A-5-9.1.3.1 (a) and (b).

    42. 42 Diagram of a Typical Combined Sprinkler and Standpipe System

    43. 43 A Typical Flow Control Assembly Located in a Stairwell

    44. 44 Buildings that Require Standpipe and Hose Systems Buildings where standpipes and hose systems are required: Any building where the highest floor level is 30 ft. or more above the lowest level of fire department vehicle access. Places of Assembly Covered Mall Buildings (e.g. Shopping Malls) Stages Underground Buildings Check the applicable building ordinance for specifics (NYS 905.3)

    45. 45 Water Supplies Water supply must be among the following: Public waterworks with adequate pressure Automatic fire pump connected to public waterworks Manually controlled fire pump in combination with pressure tanks. Pressure tanks installed in accordance with NFPA 22

    46. 46 Water Supplies (cont’d.) Manually controlled fire pumps operated by remote control devices at each hose station. Gravity tanks in accordance with NFPA 22 Automatic fire pumps connected to the public waterworks are the most common.

    47. 47 Water Supply Capacity Water supply capacity The capacity of the supply is calculated as follows: 500 gpm for the first standpipe 250 gpm for each additional standpipe Not to exceed 1250 gpm Water supply must have minimum 30 minutes duration for calculated flow

    48. 48 Additional Classification of Standpipes Wet The standpipe system is always filled with water. Dry The standpipe system contains no water. Generally used only in unheated buildings (e.g., parking garages.) Automatic Water supply capable of supplying system demand automatically. Most common type

    49. 49 Additional Classification of Standpipes (Cont’d) Manual Connected to small water supply to maintain water in the system, but inadequate to meet demand. Relies on fire department pumper to supply necessary system demand. Other types: semi-automatic dry, manual-dry (see NFPA 14 for explanations.) The Building Ordinance (NYS Building Code) prescribes which type is required.

    50. 50 Fire Pumps Fire Pumps Since most water main pressures are generally less than 100 psi at the street, a fire pump is usually required to provide adequate pressure. Fire pumps must be provided with an emergency power source. Fire pumps generally require a separate, fire rated (2 hr.) room or enclosure.

    51. 51 Typical Electric Fire Pump Installation

    52. 52 Location of Hose Connections Location of Hose Connections Height: not less than 3 ft and not more than 5 ft above floor (usually 4 ft). Class I Systems In exit stairways at each intermediate landing between floor levels. Each side of wall adjacent to exit openings of horizontal exits. Each exit passageway at entrance from building areas into passageway.

    53. 53 Location of Hose Connections (Cont’d) In covered mall buildings at entrance to each exit passageway or exit corridor, and exterior public entrances to mall. At highest landing of stairways with access to roof, and on roof where stairways do not access the roof. Additional 2-1/2” hose connection at hydraulically most remote riser to facilitate testing. See NFPA 14 for more requirements.

    54. 54 Location of Hose Connections (Cont’d) Class II Systems 1-1/2” hose stations so that all portions of each floor level are within 130 ft of a hose connection. Class III Systems As required for both Class I and Class I Systems

    55. 55 Drainage of Standpipes Each standpipe to be equipped with a means for draining Usually a drain valve is located at lowest point of standpipe, downstream of isolation valve Drain to an approved location Often drained to spill at grade

    56. 56 Fire Department Connections At least one fire department connection for each zone of each Class I and Class III system High rise buildings require two remotely located fire department connections for each zone Height: +18” to +48” above adjoining grade

    57. 57 Fire Department Connections (Cont’d) A check valve is required downstream. No shutoff valve is permitted between the fire department connection and the system. Dry piping between connection and check valve should be galvanized steel. Signage is required at each connection. See NFPA 14, Ch. 4-3.5.2 for details.

    58. 58 Sprinkler Systems Definition and purpose – a reliable water supply, piping, sprinklers, valves and accessories for the purpose of automatically extinguishing a fire. Governing Design Standards Local building code or ordinance – prescribes where sprinkler systems are required NFPA 13 Standard for the Installation of Sprinkler Systems – prescribes how sprinkler systems are to be designed and constructed Factory Mutual (FM) – An insurance company standards organization; it may, through the building owner’s insurance company, impose additional restrictions/requirements for overall building fire protection systems.

    59. 59 Sprinkler Systems (cont’d) Types of sprinkler systems: Wet Dry Pre-action Deluge

    60. 60 Sprinkler Systems (cont’d) Wet system Piping is filled with water under pressure at all times. When one or more sprinkler heads open, water is automatically discharged. Used in heated buildings or portions of buildings that are heated. Most common type of system.

    61. 61 Diagram of a Wet Pipe Sprinkler System with Water Motor Alarm Both pendant and upright sprinklers may be used. During operation, the alarm check valve diverts a small portion of water to the water motor alarm – does not rely on electricity to sound alarm.

    62. 62 A Typical Wet Pipe Sprinkler Alarm Valve Installation

    63. 63 Wet Pipe Alarm Valve

    64. 64 Wet Pipe Sprinkler with Electric Alarm An electric alarm bell is operated through a water flow switch inserted into the main riser. When a sprinkler opens, water flow activates flow switch, and alarm sounds. Requires a reliable source of power from an emergency source.

    65. 65 Sprinkler systems (cont’d) Dry system Piping is filled with compressed air. A dry system valve blocks the entry of water into the piping. Air pressure in the piping holds the valve closed. When one or more sprinkler heads open Air is first released through the head(s) Air pressure in the piping system drops. Dry system valve swings open. Water floods the piping system. Used in unheated buildings, or portions of buildings that are not heated, e.g., attics.

    66. 66 Diagram of a Dry Pipe Sprinkler System Upright heads must be used, in order to allow the piping to drain completely.

    67. 67 Sprinkler systems (cont’d) Pre-action system Requires operation of both a fire detector and a sprinkler head opening before water is released. Piping is filled with pressurized air. A fire detection system (smoke, heat detectors, manual pull station) is wired to the pre-action valve; valve is opened only when fire detection system is activated. Water floods piping.

    68. 68 Pre-action system (cont’d) Water is released from each sprinkler head that opens. Used for rooms that contain valuable equipment or materials that could be damaged be release of water, where fire detection must be verified independently. Main frame computer rooms Laboratories

    69. 69 Diagram of a Pre-Action System

    70. 70 Sprinkler Systems (cont’d) Deluge System All sprinklers are open When water fills the piping system, all sprinklers discharge water simultaneously Diagram is similar to pre-action system Applications: Where severe fire hazard exists that can be extinguished safely with water E.g. – a Fireworks Factory

    71. 71 Sprinkler systems (cont’d) Where required: Governed by the local building code or ordinance If not required by code, insurance companies often offer reduced rates, or won’t insure buildings without sprinkler systems.

    72. 72 Some Sprinkler Types Recessed Pendant Sprinkler Glass tube holds metal disc seated in valve seat Glycerin in glass tube expands when heated and will shatter glass Water is released Spray pattern is established by deflector

    73. 73 Recessed Pendant Sprinkler with Brass Finish

    74. 74 Old Style Sprinkler with Fusible Link, (Upright Style Shown)

    75. 75 Sprinkler with Wire Guard and Deflector Disk (Pendant Style Shown) This sprinkler would be used to protect combustible materials in storage racks Wire guard protects sprinkler from damage as racks are loaded/unloaded Deflector plate prevents water may be discharged from above from cooling this sprinkler and preventing its operation

    76. 76 Concealed Sprinkler Decorative white disk is soldered to the sprinkler body – solder melts first, plate falls to floor, exposing sprinkler Exposed sprinkler will now operate like a standard sprinkler - releases water as temperature increases Can be used in Light Hazard Occupancies

    77. 77 Partial Data Sheet for a Typical Concealed Sprinkler

    78. 78 Sidewall Sprinkler

    79. 79 Sprinkler systems (cont’d) Requirements for water supply capacity and spacing of sprinklers depend upon the building’s occupancy classification Occupancy Classes: Light Ordinary Group 1 Ordinary Group 2 Extra Group 1 Extra Group 2

    80. 80 Light Hazard Quantity and/or combustibility of contents is low; fires with relatively low rates of heat release are expected. Examples: Churches Libraries Restaurant seating areas

    81. 81 Ordinary Hazard Group 1 – combustibility is low, quantity of combustibles is moderate, stockpiles of combustibles do not exceed 8 ft, fires with moderate rates of heat release expected. Examples: Automobile parking and showrooms Bakeries Restaurant service areas

    82. 82 Ordinary Hazard (cont’d) Group 2 – quantity and combustibility of contents moderate to high, stockpiles do not exceed 12 ft, fires with moderate to high rates of heat release expected. Examples: Chemical plants - ordinary Dry Cleaners Library large stack room areas

    83. 83 Extra Hazard Group 1 – combustibility is low, quantity of combustibles is very high, dust, lint or other materials are present, possibility of rapidly developing fires with high rates of heat release, but little or now combustible or flammable liquids. Examples: Aircraft hangers Plywood and particle board manufacturing Printing

    84. 84 Extra Hazard (cont’d) Group 2 – moderate to substantial amounts of flammable or combustible liquids Examples: Flammable liquids spraying Plastics processing Varnish and paint dipping In all cases, refer to NFPA 13 and AHJ (Authority Having Jurisdiction) for quidance in assessing occupancy classification

    85. 85 Sprinkler systems (cont’d) Maximum Area of Coverage (Standard Spray Upright and Pendant Sprinklers) Light hazard: 225 s.f., maximum 15’ between sprinklers Ordinary hazard: 130 s.f., maximum 15’ between sprinklers Extra hazard: 90 s.f., maximum 12’ between sprinklers (see NFPA 13 for exceptions) Protection Area per sprinklers: S x L, where S = spacing between sprinklers or twice distance to end wall, whichever is greater. L = spacing between branch lines or twice the distance to end wall, whichever is greater.

    86. 86 Sprinkler systems (cont’d) Maximum distance from walls: less than ˝ spacing. Minimum distance to walls: 4” Where walls are angled or irregular, the maximum distance to any point on floor – 0.75 spacing, with maximum perpendicular distance to wall not exceeded. Minimum distance between sprinklers: 6’ (see exceptions NFPA 13)

    87. 87 Sprinkler Location Deflector position Standard spray pendant or upright heads: minimum 1” to maximum 12” from ceiling. Standard spray sidewall sprinklers: minimum 4” to maximum 6” from ceiling. (In special situations, 6 to 12” – see NFPA 13) Critical point – the farther the sprinkler is from the ceiling, the longer it will take for the heat to collect at the ceiling plane and set off the sprinkler.

    88. 88 Typical Symbols

    89. 89 Sprinkler Spacing Examples Light Hazard Occupancy 225 s.f. per sprinkler Maximum 15’ between branch lines and between sprinklers on branch lines Maximum 15/2 = 7.5 from wall to outermost sprinkler and branch lines Here, S=L=15’

    90. 90 Sprinkler Spacing Example No. 2 Occupancy Hazard: Ordinary Group 1 Maximum coverage per sprinkler: 130 s.f. Maximum spacing: 15’

    91. 91 Example No. 2 – Proposed Solution Area of coverage is 10’x 13’ = 130 s.f. Maximum spacing is 13’, which is less than the maximum 15’ allowed Maximum distance to wall is 6.5’, which is ˝ the largest spacing (13’) Yet this solution does not comply with NFPA 13!

    92. 92 Example No. 2 (cont’d) Area of coverage of sprinkler in NW corner is: (6+5) x 13 = 141 s.f. The number of sprinklers required is actually (41’ x 39’)/130 s.f. per sprinkler = 12.3; the proposed solution has just 12

    93. 93 Example No. 2 (cont’d) Here is one correct solution. More sprinklers are required in order to comply with both spacing and area of coverage requirements. S=12’ (2 x 6); L=9’-8” A=12’ x 9’-8” = 116.04 s.f

    94. 94 Example No. 2 (cont’d) If a 2’x2’ suspended tile ceiling is used, the sprinklers will not be centered within the tiles.

    95. 95 Example No. 2 (conclusion) Since we have more sprinklers than are needed, we can shift the centerlines slightly to achieve center of tile placement of sprinklers. In this example, the dashed area represents greatest coverage, = (5’-6” +5’-0”) x (5’-0” + 6’-0”) = 126.5 s.f.

    96. 96 Sprinkler Systems (cont’d) Sprinkler Classifications Design and performance Area of coverage Speed of response Standard response Fast response Orientation Concealed Flush Pendent Recessed Sidewall Upright

    97. 97 Sprinkler Classifications (cont’d) Special service conditions Dry Corrosion resistant Intermediate level sprinkler/rack storage sprinkler

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