8/10/2019 Training Fire Protection
1/32
AIA Middle EastA309
Life safety- engineeringmeans of egressBahrain
Allan ComelloApril 17, 2013
8/10/2019 Training Fire Protection
2/32
8/10/2019 Training Fire Protection
3/32
This presentation is protected by US and International Copyright laws.Reproduction, distribution, display and use of the presentation without written
permission of the speaker is prohibited.
Trinity Bahrain 2013
Copyright Materials
8/10/2019 Training Fire Protection
4/32
1) Illustrates the safety challenges posed by high-rise buildings
2) Describes the requirements for fire protection and prevention
3) Describes system & design requirements, as per the standards,of Smoke Management Systems
4) Explains stair pressurization, components, and its working
5) Discusses passive fire safety elements in the building as a first line ofdefense in fire emergencies
6) Proposes strict adherence to standards and quality procedures for design,specification, installation and maintenance of stairwell pressurization componentsfor a safe means of egress
Course
Description
8/10/2019 Training Fire Protection
5/32
Learning
Objectives
1. Participants will learn about safety challenges posed by high-rise buildings
2. Participants will have an understanding of the design specifications and
systems requirements of stairwell pressurization system as per the safetycodes and standards
3. Participants will gain knowledge about stairwell pressurization as an effectivesmoke management method in high-rise buildings
4. Participants will learn from the on-site experiences and examples provided
8/10/2019 Training Fire Protection
6/32
Presenter: Allan Comello
LIFE SAFETY
Engineering Means of Egress
8/10/2019 Training Fire Protection
7/32
"Any building greater than 23 meters (75.5 ft) in
height, where building height is measured from the
lowest level of f ire department vehicle access to the
floor of the highest occupiable story.
- NFPA 101 Life Safety Code (LSC) 3.3.27.7
High-rise building
NFPA : Height > 23m
I.B.C.: Height > 23m
8/10/2019 Training Fire Protection
8/32
Each year, an estimated 15,500 high-rise structure fires cause60 civilian deaths, 930 injuries, and $252 millionin property loss
Three-quarters of high-rise fires are in residential structures
The leading cause of all high-rise fires is cooking (38%)
Four property types make up 50% of the high-rise firesreported (Apartments 44%, Hotels 2%, Hospitals, Clinics,doctors offices 2%; Other offices 2%)
69% of high-rise structure fires originate on the 4th floor or
below; 60% occur in apartment buildings; 43% originate in thekitchen
High-rise fires are inherently more difficult for occupantevacuation
Sources: NFPA and NFIRS
High- rise buildings- Fire statistics
8/10/2019 Training Fire Protection
9/32
Challenges posed by high-rise fires
Temperature gradients leading to varying pressures throughoutthe structure result in rapid spread of smoke and flame
Fire fighting in multiple types of occupancies, includingresidential, commercial, restaurant, and underground parking,need to be approached differently
By design, exits from high-rise structures are limited. Thismakes the movement of people out of a building difficult inan emergency
Improper Installation, sequencing and irregular maintenanceof HVAC, Fire Fighting System & Fire Detection System
High-rise structure fires require significantly more personneland equipment to extinguish than do other types of fires
8/10/2019 Training Fire Protection
10/32
Safe egress concerns
Fire extension & smoke spreadStack effectInadequate systemsand evacuation method
Engineering means of egress
8/10/2019 Training Fire Protection
11/32
Fire extension & toxic smoke spread
Vertical design of high-rise buildings is susceptible to rapid fire extension
Common avenues for f ire spread
Poke-thru construction
Lapping
Radiated heat through flooring
HVAC ducting The gap between the exterior panels
and interior beams
8/10/2019 Training Fire Protection
12/32
Fire & smoke spread rate
Fire can travel up to 70mph.
Smoke can travel at a speed of over 2m/s, this isfaster than the probable escape speed of an occupant
8/10/2019 Training Fire Protection
13/32
Stack effect
Stack effect is defined as " the vertical, natural airmovement throughout a high-rise building caused
by the difference in the outside and inside air
temperatures.
Positive stack effect
Negative stalk effect
Influencing factors:
Airtight exterior walls
Air leakage between floors
Air temperature between floors
Differences between inside and outside
air temperature
8/10/2019 Training Fire Protection
14/32
Inadequate Systems
Smoke management systems are required to meet specific
building codes for fire resistance. Failure of these systems canhinder fire department operations resulting in a large fire.
Active fi re protection systemsSmoke detectorsFire alarms systems
Sprinkler systemsHVAC systems
Passive fire protection systemsStair & lift lobby pressurizationFire resistant doors
Fire walls/ barriersFire dampersMotorised Smoke & Fire DamperSmoke Exhaust System at fire floor
8/10/2019 Training Fire Protection
15/32
Methods of smoke control
Dilution
Buoyancy
Compartmentation
Smoke exhaust at fire floor
Purpose of Smoke-Control Systems
Inhibiting migration of smoke out of the source compartment
Inhibiting smoke from entering means of egress (maintainingtenable environment for evacuees) Maintaining a tenable environment outside of the sourcecompartment for emergency personnel
Protecting life Reducing damage to property
-NFPA 92A (2000)
Pressurization
Ai rflow (HVAC)
8/10/2019 Training Fire Protection
16/32
Stairwell pressurization
A type of smoke-control system in which
stair shafts are mechanically pressurized,with respect to the fire area, with outdoor
air to keep smoke from contaminating
them during a fire incident.
- NFPA 92 A
ComponentsStair Pressurization Fans
Ductwork and Accessories
Pressure Relief Dampers
Fire Alarm Systems
Fire rated doorsBuilding Automation Systems (BAS)
Source: NFPA
8/10/2019 Training Fire Protection
17/32
Working of Stairwell
Pressurization
1) Under normal conditions, the pressurization fan should not run and the dampers on the airintake and bypass ducts shall be closed
2) In a fire situation, through a signal from the fire alarm panel, the damper on the air intake
shall open . An end switch on the damper actuator shall signal the fan to run when thedamper is open
3) A pressure sensor installed in the stairwell shall control the bypass damper to maintain aconstant pressure of 50Pa within the stairwell
4) The fan should be wired for manual stopping5) It should be possible to override all controls and run the system through the firemans smoke
control panel
Roof
Fire Alarm Panel
Fire Mans smoke
Starter / ControlPanel
Staircase
Bypass Duct
Source: Trinity
8/10/2019 Training Fire Protection
18/32
Stair pressurization fansStair pressurization systems utilize a single
fan with a ducted shaft to multiple injectionpoints or multiple fans distributed over theheight of the stair. Smoke exhaust fans mustbe rated and certified by the manufacturer forvarying temperatures to which they areexposed. The fans must have smokedetectors in their inlets to stop them from
injecting smoke into a protected compartment.
Fan status and on-off-auto override switchesare required at the firefighters smoke controlpanel. Excess pressures could deactivate fansystems, making them unusable for smoke
control.
8/10/2019 Training Fire Protection
19/32
8/10/2019 Training Fire Protection
20/32
Egress system design, installation & coordination
Coordination between fans and dampers in smoke control systemsrequires consideration of the installation geometry, control sequence ofoperation, and sensor locations.
Mechanical and electrical concerns:
Fan volume and pressuresDamper tolerance to the pressuresStraight duct entrances to the equipment
8/10/2019 Training Fire Protection
21/32
NFPA standards for HVAC equipment
HVAC equipment used for smoke control purposes shall bepermitted to be located within the conditioned space, withinadjacent spaces, or within remote mechanical equipment rooms.
HVAC systems used for smoke-control purposes shall beprovided with outside air for pressurization.
Where supply and return air systems are interconnected as partof normal HVAC operation, smoke dampers shall be provided toseparate the supply and exhaust during smoke-control operation.
Smoke dampers used to protect openings in smoke barriers orused as safety-related dampers in engineered smoke-controlsystems shall be listed and labeled in accordance with UL 555S.
Standard for Smoke Dampers. 92A
8/10/2019 Training Fire Protection
22/32
Motorised Smoke & Fire Dampers (MSFD)The dampers used in smoke control systems mustbe Motorised Smoke & Fire Dampers and listed to
UL555S. They need to be evaluated for their abilityto operate under anticipated conditions of systemoperation. The connections to and from fans anddampers must take system effect into account. Highpressure losses due to construction geometry cancause insufficient pressure. Motorised Smoke & Fire
Dampers actuate with pneumatic actuation andelectrical actuation.
Emergency lighting
In buildings where artificial lighting is provided fornormal use and occupancy, exit lighting and the
illumination of the means of egress is required toassure occupants can quickly evacuate the building.
All emergency lighting must be installed and tested inaccordance with NFPA 111 (Full 1 hour test annuallyand 30-second test every 30 days.)
8/10/2019 Training Fire Protection
23/32
Fire rated doors ensure adequatecompartmentation of buildings tocontain fire in the compartment inwhich it starts providing a means ofescape .
Fire Doors are regulated by thebuilding code and NFPA throughoutdesign, specification, installationand occupancy permitting.
Compartmentation &
Fire resistant doors
8/10/2019 Training Fire Protection
24/32
Fire rated doors- codes and standards
Doors from the building to the smoke proof enclosures vestibule must be 1 -hour fire rated.-IBC 1020 and NFPA 101
Doors from the smoke proof enclosures vestibule to the stairwell must be not less than 20-minute fire rated.-IBC 909 and 909
Stairwell doors, which can be locked, must be provided with automatic electrical unlocking from the centralstation. Telephones or other two-way communication systems must be provided at not less than every fifth
floor inside the stairwell.-IBC 403
Provide a sign at each floor level landing five feet above the landing that is visible when the door is openedor closed. The sign must indicate the floor level, the terminus of the top and bottom of the stair enclosure,and the identification of the stair.-NFPA 101
Doors located in smoke barriers shall be self-closing or shall be arranged to close automatically upon the
activation of the smoke control system.- NFPA 92A-5
Stairwell pressurization systems shall be designed to achieve the required pressure difference with a singledoor open to the interior of the building.- NFPA 92A-5
8/10/2019 Training Fire Protection
25/32
The components of the means of egress shouldstrictly adhere to quality standards and NFPAspecifications
It is critical that on an outbreak of fire the
components of the means of egress have thecapacity to withstand fire and pressure variations
Openings in smoke barriers, number of doors open,door capacity and resistance are integral to safe exit
Guidelines to be followed for installing fire doors,frames and hardware at the stairwell opening
Design & engineering of egress components
8/10/2019 Training Fire Protection
26/32
The required capacity of the pressurization fansincreases as area created by a partially open
stairwell door increases
Designs shall incorporate the effect of outdoortemperature and wind on the performance of thesmoke management system.
A door in a means of egress should be side-
hinged and must swing in the direction of theexit
Locks on doors in the means of egress shallopen the door with not more than one releasingoperation
A latch or other fastening device on a door shallbe provided with a releasing device that can bereadily operated under all conditions.
8/10/2019 Training Fire Protection
27/32
27
Facility Managers should keep vigil on theuse of quality fire safety items
manufactured by certified and experiencedcompanies.
Fire alarm system to be designed, installed,
inspected, tested, and maintained per
NFPA 72
Luminescent markings to egress pathsas per NFPAs Life Safety Code will helpbuilding occupants reach an exit faster
8/10/2019 Training Fire Protection
28/32
Lessons learnt from on-site experience
There should be separate ducts for stairwell pressurization rather than usingMasonry Shaft for air to avoid air leakages and get proper pressurization.
All ducts used for Pressurization and Smoke Exhaust System shall be firerated, many contractors are using normal GI Ducts which defeats thepurpose.
Elevator hoist ways have proved to be readily available conduit for movementof smoke throughout buildings in past fires. This is because the leakagethrough elevator doors and elevator hoist ways. The building stack effect hasprovided the driving force that has readily moved smoke into and out of theloosely constructed elevator hoist ways. Methods of correcting this problem
include:1) Exhaust of the fire floor
2) Pressurization of elevator lobbies
3) Construction of smoke tight elevator lobbies
4) Pressurization of the elevator hoist way
5) Closing elevator doors after automatic recall
8/10/2019 Training Fire Protection
29/32
Lack of periodical testing and maintenance of the egress components lead tosystem failure. A written record of the inspection shall be signed and kept for
the annual inspection of the local authorities.
Functional testing of fire door and window assemblies shall be performed bycertified companies.
Adequate latching and closing force need to be maintained for doors
8/10/2019 Training Fire Protection
30/32
Inadequate or faulty Smoke Management Systems often lead tolarge fire
Commonly observed flaws include: The failure of one component often leads to the failure of
other fire protection systems
Improperly set pressure reducing valves
Electrical system failure
It is paramount that local legislation imposes strict rules for the properinstallation, maintenance and service of fire safety items that are part ofthe means of egress
8/10/2019 Training Fire Protection
31/32
References
NFPA 101- Standards for Life Safety
NFPA 80 - Fire door assembly inspection NFPA 80- Fire Doors and other opening
NFPA 101- Occupancy classification
AHRAE Chapter 52- Fire and Smoke Management.
NFPA 90 A- Standard for Installation of Air Conditioning and Ventilation Systems
NFPA 92A- Recommended practice for smoke control systems
NFPA 105- Standard for Smoke Door Assemblies and Other Opening NFPA 252- Standard Methods of Fire Tests of Door Assemblies
Wild, J.A., Fans for Fire Smoke Venting, Woods Air Movement Ltd
Technical Paper WTP20,1989
Klote, J.K. and Milke, J.A., Design of Smoke Management Systems,
American Society of Heating, Refrigerating and Air-conditioning
Engineers, 1992. Felker, Larry, Heating/Piping/Air Conditioning Engineering, 2004.
8/10/2019 Training Fire Protection
32/32
This concludes The American Institute of ArchitectsContinuing Education Systems Course
Allan Comello+971509204011