Essentials of Fire Fighting , 5 th Edition

1. Essentials of Fire Fighting, 5th Edition Chapter 16 — Fire Detection, Alarm, and Suppression Systems Firefighter II

2. Chapter 16 Lesson Goal • After completing this lesson, the student shall be able to operate different types of fire detection, alarm, and suppression systems and identify the different types of alarm and auxiliary systems following the policies and procedures set forth by the authority having jurisdiction (AHJ). Firefighter II

3. Specific Objectives 1. Describe types of heat detectors. 2. Describe types of smoke detectors/alarms. 3. Explain how flame detectors and fire-gas detectors operate. (Continued) Firefighter II

4. Specific Objectives 4. Discuss combination detectors and indicating devices. 5. Describe types of automatic alarm systems. 6. Discuss supervising fire alarm systems and auxiliary services. (Continued) Firefighter II

5. Specific Objectives 7. Describe the operation of an automatic fire sprinkler system. 8. Discuss water supply for sprinkler systems. 9. Describe major applications of sprinkler systems. Firefighter II

6. Fixed-Temperature Heat Detectors • Relatively inexpensive compared to other types of systems • Can be slowest to activate • Activate when heated to temperature for which rated (Continued) Firefighter II

7. Fixed-Temperature Heat Detectors • Installed in highest portions of room • Should have activation temperature rating slightly above highest ceiling temperatures normally inspected in space (Continued) Firefighter II

8. Fixed-Temperature Heat Detectors • Activate by one or more of three mechanisms • Fusible device • Frangible bulb • Continuous line detector Firefighter II

9. Rate-of-Rise Heat Detectors • Operate on assumption that temperature in room will increase faster from fire than from normal atmospheric heating • Designed to initiate signal when rise in temperature exceeds 12° to 15°F (-11°C to -9°C) in one minute (Continued) Firefighter II

10. Rate-of-Rise Heat Detectors • Can be initiated at room temperature far below that required for initiating fixed-temperature device • Reliable, not subject to false activations • Pneumatic rate-of-rise spot detector (Continued) Firefighter II

11. Rate-of-Rise Heat Detectors • Pneumatic rate-of-rise line detector • Rate-compensated detector • Thermoelectric detector Firefighter II

12. Smoke Detectors • Detect presence of smoke; must transmit signal to another device that sounds alarm • Respond to smoke or other products of combustion • Preferred over heat detectors Firefighter II

13. Smoke Alarms • Capable of • Detecting presence of smoke • Sounding an alarm Firefighter II

14. Photoelectric Smoke Detectors • Use photoelectric cell coupled with tiny light source • Function in two ways to detect smoke Firefighter II

15. Ionization Smoke Detectors • Detect minute particles, aerosols produced during combustion • Use a tiny amount of radioactive material to ionize air molecules as they enter chamber within detector (Continued) Firefighter II

16. Ionization Smoke Detectors • Respond satisfactorily to most fires • Respond faster to flaming fires than smoldering ones Firefighter II

17. Power Sources of Smoke Alarms • Battery-operated • Household current Firefighter II

18. Flame Detectors • Types • Among most sensitive detectors used to detect fires • Prone to being activated by nonfire conditions (Continued) Firefighter II

19. Flame Detectors • Usually positioned in areas where other light sources unlikely • Positioned to have unobstructed view of protected area (Continued) Firefighter II

20. Flame Detectors • Some single-band IR detectors sensitive to sunlight, should be installed in fully enclosed areas • UV detectors virtually insensitive to sunlight, can be used in areas not suitable for IR detectors Firefighter II

21. Fire-Gas Detectors • Monitor levels of carbon dioxide, carbon monoxide because these are only chemicals released from all fires • Initiate alarm signal faster than heat detector but not as quickly as smoke detector (Continued) Firefighter II

22. Fire-Gas Detectors • Can be more discriminating than other types • Can be designed to be sensitive only to specific gases (Continued) Firefighter II

23. Fire-Gas Detectors • Use semiconductors/catalytic elements to sense gas, transmit signal to initiate alarm • Not used as frequently as other types Firefighter II

24. Combination Detectors Various combinations of previously described means of detection may be used in single device Firefighter II

25. Indicating Devices • Some produce loud signal to attract attention in high-noise areas • Some generate electronic tone audible in almost any type of environment • Some employ bells, horns, chimes (Continued) Firefighter II

26. Indicating Devices • Others use speakers that broadcast prerecorded evacuation instructions • May include visual alarm indicators to accommodate special circumstances/populations (Continued) Firefighter II

27. Indicating Devices • May include strobe indicators — Must meet requirements of Americans with Disabilities Act in areas where there may be people with hearing impairments Firefighter II

28. Automatic Alarm Systems • Transmit signal to off-site location to summon organized assistance • Produce automatic response upon activation of local alarm • May be installed to complement wet-pipe or dry-pipe sprinkler systems Firefighter II

29. Auxiliary Systems • Local energy systems • Shunt systems • Parallel telephone systems Firefighter II

30. Remote Station Systems • Similar to auxiliary systems but connected to fire department telecommunication center directly/through answering service by some means other than municipal fire alarm box system (Continued) Firefighter II

31. Remote Station Systems • Can be connected by leased telephone line or radio signal on dedicated frequency • Common in localities not served by central station systems (Continued) Firefighter II

32. Remote Station Systems • May transmit coded or noncoded signal • Must have ability to transmit trouble signal to fire alarm center when system impaired (Continued) Firefighter II

33. Remote Station Systems • May not have local alarm capabilities if evacuation is not desired action in fire • May be monitored by entity besides fire department Firefighter II

34. Proprietary Systems • Used to protect large commercial, industrial buildings, high-rise buildings, groups of commonly owned buildings in single location (Continued) Firefighter II

35. Proprietary Systems • Each building/area has own system wired into a common receiving point somewhere on facility • The receiving station • Capabilities Firefighter II

36. Central Station Systems • Very similar to proprietary systems; instead of having alarm-receiving point monitored by occupant’s representative on protected premises, receiving point is at off-site, contracted service point called a central station (Continued) Firefighter II

37. Central Station Systems • Central station is alarm company that contracts with individual customers (Continued) Firefighter II

38. Central Station Systems • When alarm initiated at contracting occupancy, central station employees take information, initiate appropriate emergency response • Response usually includes calling fire department, representatives of protected occupancy (Continued) Firefighter II

39. Central Station Systems • Alarm systems at protected property and central station most commonly connected by supervised telephone lines Firefighter II

40. Supervising Fire Alarm Systems • Designed to be self-supervising • Older systems • Newer systems (Continued) Firefighter II

41. Supervising Fire Alarm Systems • Sounds of alarm, trouble signals may differ with each brand • Many fixed fire suppression systems depend on signal from manual pull station/from automatic fire detection device to trigger suppression system Firefighter II

42. Auxiliary Services Available on Newer Systems • Shutting down, altering airflow in heating, ventilating, and air-conditioning (HVAC) systems for smoke control • Closing smoke/fire-rated doors, dampers (Continued) Firefighter II

43. Auxiliary Services Available on Newer Systems • Facilitating evacuation by increasing air pressure in stairwells to exclude smoke • Overriding elevator controls • Monitoring operation of commercial incinerator management systems (Continued) Firefighter II

44. Auxiliary Services Available on Newer Systems • Monitoring refrigeration systems, cold-storage areas • Controlling personnel access to hazardous process/storage areas • Detecting combustible/toxic gases Firefighter II

45. Principle Parts of Automatic Sprinkler System • Water supply • Sprinkler valve • Alarm • Manual valve • System drain (Continued) Firefighter II

46. Principle Parts of Automatic Sprinkler System • Test connection • Sprinkler head • Riser • Feed main • Cross mains Firefighter II

47. Sprinklers • Discharge water after release of cap or plug activated by some heat-responsive element such as fusible link (Continued) Firefighter II

48. Sprinklers • Identified by temperature at which designed to operate, either by color-coding, using different colored liquid, stamping temperature on sprinkler (Continued) Firefighter II

49. Sprinklers • Fusible link • Frangible bulb (Continued) Firefighter II

50. Sprinklers • Chemical pellet Firefighter II