4 Building Systems Flashcards Preview

Building Construction Related To The Fire Service > 4 Building Systems > Flashcards

Flashcards in 4 Building Systems Deck (107)
Loading flashcards...
61

Refuse chute

Provides for the removal of trash and garbage from upper floors extending through the building with openings on each floor the depositing of trash or linen

62

Grease duct

Part of exhaust system for commercial cooking appliances that produce grease laden vapors.

63

Nfpa 90a

Standard for the installation of air conditioning and ventilation systems

64

Hvac ducts often travel vertically through multistory buildings. with few minor exceptions the code requires hvac duct to be

Enclosed in fire rated shaft

65

Nfpa 90a requires hvac ducts be in an enclosure rated at

1 hr for les than four story building, 2 hr for higher buildings.

66

True, false. Hvac systems cannot distribute products of combustion throughout the structure.

False. Hvac can spread combustion products

67

Duct

Channel or enclosure , sheet metal, used to move heat and cooling through a building. Hollow pathways used to move air from one area to another in ventilation system

68

Interstitial space.

In building construction, refers to generally inaccessible spaces between layers of building materials. May be large enough to spread fire.

69

Duct detectors are provided for fans with capacities exceeding

2000 cubic feet per min

70

Natural gas collects in what parts of buildings

Upper parts, it's lighter so it rises.

71

Log, propane, collects in what part of buildings

Lower parts, it's heavier so it sinks.

72

Sometimes interstitial spaces are used as what for hvac

Return air plenum. Instead of duct work, though limited by code

73

Smoke control system

Engineered system designed to control smoke by using the mechanical fans to produce air flows and pressure differences across smoke barriers to limit and direct smoke movement

74

Automatic smoke control

Smoke control systems in hvac disengaged to be automatically initiated by fire protection detection sensors, actuating dampers or venting smoke outside.

75

Automatic smoke control requires careful coordination of fire protection sensors because

Improper coordination of sensors and false activations can cause automatic smoke control to mitigate the wrong area.

76

Advantage of manual smoke control system

Elimination of system disruption from false alarms. Specific control of system through firefighter smoke control station, manual takes priority over automatic.

77

Disadvantage to manual smoke control

Delay in mitigating smoke in building, potentially allowing fire headway

78

Smoke control system should not be activated using

The manual pull stations to avoid pull stations being activated in area other than fire and improperly activating system in wrong area

79

Two methods to protect stairwells from smoke

Smoke proof tower. Stairwell pressurization

80

Smoke proof tower

Smoke proof enclosure that makes use of vestibule between corridor and the stairwell that is open to outside air, isolating stairs from interior of building.

81

Pressurized stairwell

Blower or fan pressurizes stairs to keep smoke out

82

Nfpa 92a

Standard for smoke control systems utilizing barriers and pressure differences.

83

Stairwell pressurization method where fan supplies air at a single point

Single injection method, can cause loss of pressure if door opened close to fan

84

Stairwell Multiple injection system

Air forced into stairwells at multiple levels through ducts to overcome limitations of single method.

85

Compensated pressurized stairwell

Air pressure is adjusted based on pressure detected in stairwell, adjusting as doors open an close

86

Stairwell pressurization, over pressure relief

Weighted dampers to outside forced open if stairwell is over pressurized. Automatic dampers opened by pressure switches. P

87

Smoke and heat vent minimum size for small hatchways

4 feet

88

Curtain boards

Vertical boards, fire resistive half walls, that extend down from the underside of a roof underneath and ceasing the opening for roof vent, intended to limit spread of fire and smoke

89

Curtain boards are designed to reduce fire spread and increase efficiency of fire and heat vents, minimum depth of boards is

No less than 20% of the ceiling height.

90

Voltage

The electrical force that causes a charge (electrons) to move through a conductor. Sometimes called electromotive force, EMF