Module 7. Control of Smoke & Highlights of Code Requirements

Transcription

1 Module 7 Control of Smoke & Highlights of Code Requirements 1

2 Module 7 Overview This module will cover: 1. The requirements of smoke control in the Ohio Building Code Section The differences between active and passive systems 3. The components of a smoke control system 4. The requirements of smoke and heat vents per Section 910 OBC. 5. The differences between the mechanical and manual activation of smoke exhaust systems 2

3 Smoke Control Systems An engineered system that includes all methods that can be used singly or in combination to modify smoke movement Two types: Passive Active NFPA Standards 92B-09: Standard for Smoke Management Systems in Malls, Atria, and Large Spaces 3

4 Smoke Control Systems: Passive Any portion of a building or structure that provides protection from smoke without any type of system activation or movement. Use compartmentalization, reservoirs or other methods to control smoke to a predetermined habitable level Utilized when active control systems are not feasible and/or to help them function Relies on the natural buoyancy of the smoke and the stack effect to allow the smoke to exit the building. 4

5 Smoke Control Systems: Passive High Bay/ High Ceilings Act as a reservoir to contain smoke Natural ventilation The flow of air or gases created by the difference in the pressures or gas densities between the outside and inside of a vent, room, or space. Open exterior balcony or vestibule with opening 16 sq. ft. in area facing an open area that is at least 20 ft. in width. 5

6 Smoke Control Systems: Passive Operable or break-out windows Manually controlled Fusible Link Operated Vent A fusible link holds open springloaded fire-rated damper The link is designed to melt at a certain temperature When it melts the damper slams shut. Operable window 6

7 Smoke Control Systems: Active A system that uses moving mechanical or electrical parts to achieve a smoke control goal. Also known as mechanical Preferred method of smoke control 7

8 Smoke Control Systems: Active Exhaust Air removed from a space or power system and not reused. Pulls smoke from space Utilizes: Automatic detection Exhaust fans Make up air Colt International Ltd 8

9 Smoke Control Systems: Active Pressurization Uses wall and floor assemblies with pressure difference Fans create the pressure difference Default design method in the IBC Indiana University of Pennsylvania 9

10 Smoke Control Systems: Active Airflow Large airflows from adjacent compartments to fire compartment Difficult to achieve Typically utilizes air-moving device Most commonly used to stop smoke movement through open doorways and corridors 10

11 Smoke Control Systems: Components Figure 702.1(11) SMOKE BARRIER Smoke barrier A continuous membrane, or a membrane with discontinuities created by protected openings, where such membrane is designed and constructed to restrict the movement of smoke. Smoke zone: The smoke control zone in which the fire is located. NFPA Standards 92B-09: Standard for Smoke Management Systems in Malls, Atria, and Large Spaces International Building Code Commentary 11

12 Smoke Control Systems: Components Control panel Intended to communicate with fire fighters Installed in approved location adjacent to fire alarm panel KMC Controls, Inc. 12

13 Smoke Control Systems: Components Power supply The system is supplied with two sources of power Primary power shall be from the normal building power systems. Secondary power shall be from an approved standby source complying with Chapter 27 of the Building Code. 13

14 Smoke Control Systems: Components Smoke detector A device that detects visible or invisible particles of combustion issue a signal to a fire alarm control panel as part of a fire alarm system Wikimedia Commons 14

15 Smoke Control Systems: Components Fans A blower or exhauster assembly comprising blades or runners and housings or casings. Examples Pressurization Exhaust Colt Group Ltd/ 15

16 Smoke Control Systems: Components Ducts Pipes, tubes, or other enclosures used for the purpose of pneumatically conveying materials Examples Exhaust Supply LifeSafety Magazine 16

17 Smoke Control Systems: Components Make-up air inlets Controlled air vents that allow for fresh, draft-free make-up air to enter a building. Make-up air is provided for exhaust systems Replaces the air that is removed Luxury Metals LLC 17

18 Smoke Control Systems: Components Smoke Dampers A device within an air distribution system to control the movement of smoke Closes upon actuation of a listed smoke detector or detectors Wikimedia Commons 18

19 Smoke and Heat Vents Openings in the roof which are intended to vent the heat and smoke developed by a fire inside the building NFPA Standards: 204: Standard for Smoke and Heat Venting for information only, not listed in chapter 35 OBC Smye Holland Associates Limited 19

20 Unit-type vents Small openings on a structure s roof, equipped with a metal frame and housing and manual or automatic hinged dampers, which are opened in case of fire. Using mechanical openings Using gravity openings 20

21 Unit-type vents Using mechanical openings A small openings on a structure s roof, equipped with a metal frame and housing and automatic hinged dampers, which are opened in case of fire. Spring lift Pneumatic lift Electric motor-driven lift National Domelight Company 21

22 Unit-type vents Using mechanical openings: Spring Tension is maintained on a fusible link with the use of a heavy duty spring. High temperatures melt the fusible link Santa Barbara County Fire Dept 22

23 Unit-type vents Using mechanical openings: Pneumatic Lift uses a pressurized air system to open the vent automatically with a loss, or activation, of air pressure Babcock-Davis 23

24 Unit-type vents Using mechanical openings: Electric motor-driven lift equipped with electrical links that trigger the vent opening when connected to a remote smoke or fire alarm. FAKRO 24

25 Smoke and Heat Vents: Unit-type vents Using gravity openings: Plastic shrink-out panels Constructed of plastic which shrinks in the presence of heat drop-out panel HPAC Engineering 25

26 Mechanically-powered venting systems Consists of fixed, motor-driven fans that can be mounted on the roofs Rely on mechanical extraction of smoke through fans. Energy Vanguard's 26

27 Glass roof and continuous gravity vents Ordinary glass roof vents Vents in glass roofs Continuous gravity vents (ridge vents) Installed at the peak of a sloped roof which allows smoke to escape a building's attic. 27

28 Mechanical smoke- exhaust systems A dedicated or shared-duty fan system designed and suitable for the removal of heat and smoke. May be an acceptable alternative to smoke and heat vents. Colt International Licensing Ltd 28

29 Manually-activated smoke exhaust systems Operated by the fire department Are an acceptable alternate to smoke and heat vents 29

30 Why are smoke control systems are required? To improve conditions in common areas to facilitate safe escape for occupants when a fire occurs To enable the fire to be fought in its early stages 30

31 When are smoke control systems required? 1. Determine the location of the top floor above ground floor level 2. The nature of occupancy 3. Location of the building above the fire service access level, then a fire fighting core(s) is required. 31

32 Codes and Standards: OBC Smoke Control- Atriums Smoke Control- Covered malls and other mall buildings Wikimedia Commons 32

33 Codes and Standards: OBC Smoke Control- Means of egress Smoke Control- Stages Smoke Control- High Rise Buildings 33

34 Codes and Standards: OBC Smoke Control- Underground Buildings Smoke Control- Groups H-3 and H Analysis 34

35 Codes and Standards: OBC Pressurization Methods Airflow Design Method Exhaust Method System Acceptance 35

36 Codes and Standards: OBC Exhaust Method System Acceptance Special Inspection for smoke control Wikimedia Commons 36

37 Codes and Standards: OBC Special Inspection for Smoke Control Smoke and heat vents- Where required Design and installation 37

38 Codes and Standards: OBC Vent operation Sprinklered buildings Nonsprinklered buildings Vent dimensions Wikimedia Commons 38

39 Codes and Standards: OBC Draft curtains Mechanical smoke exhaust Manually activated smoke exhaust system Group F-1 and S-1 increase maximum travel distance 39

40 Codes and Standards: OFC Chapter 23: High-Piled Combustible Storage High piled storage in excess of 12 feet requires specific consideration, including fire protection design features and smoke and heat vents in order to be adequately protected. Not all high-piled storage will require the use of smoke and heat vents and draft curtains. If properly sprinklered, draft curtains aren t required. Fairfax County Va. 40

41 Code and Standards: NFPA 92B: Smoke Management Systems in Malls, Atria, and Large Spaces This standard provides methodologies for estimating the location of smoke within a large-volume space due to a fire either in the large-volume space or in an adjacent space. 41

42 Lessons learned in Module 7 1. There are two types of smoke control systems, passive and active. 2. Smoke control systems must be supplied with two sources of power. 3. Smoke control systems are designed to improve conditions in common areas, to facilitate safe escape for occupants when a fire occurs, and to enable the fire to be fought in its early stages 4. Unit type vents are small openings on a structure s roof, equipped with a metal frame and housing and manual or automatic hinged dampers, which are opened in case of fire. 5. Chapter 23 of the Ohio Fire Code regulates high piled combustible storage. 42