Presentation of a Case Study
EGRESS AND SMOKE MOVEMENT
MODELING AT
5 BEEKMAN STREET
for the
New Jersey Chapter
Society of Fire Protection Engineers
September 9, 2013
Introduction
1.
2.
3.
4.
5.
Building Description
Project Overview
Atrium Details
Atrium Challenges
Atrium Solutions
6.
7.
8.
9.
10.
Smoke & Egress Models
Applicable Codes & Standards
Tenability Criteria
Design Fire Scenarios
Analysis of Models
Building Description
•
150,000 square feet
•
Originally constructed in 1882
•
First “fireproof” office building
•
Located in historic district
Project Overview
Conversion to hotel occupancy with
new hotel/residential tower addition.
New Tower
Annex
Original
Building
Atrium Details
•
9 stories and 144 feet in height
•
Floor openings 28 ft by 21 ft
•
Skylight completely overhangs
9th Floor
•
Decorative stair and elevators
open to atrium
•
SHPO request to maintain
“original historic fabric”
Atrium Details
Fire rating separating the egress balcony from guest rooms
Exit
Stair
Exit
Stair
2-hr Atrium
Separation
Balcony
Walkway
Atrium
Means of Egress
Elevators and
Open Stair
Atrium and guest room egress through 2-hour atrium separation to
new exit stairs.
Paths of
Egress
Atrium Challenges
• Using prescriptive design = large smoke exhaust
capacity
• Limited physical means to provide smoke exhaust
• Open stairs and elevators connect at all levels of
atrium without separation
• Skylight overhanging upper balcony
• Maintain original historic appearance
Atrium Solutions
• Maximize smoke exhaust capacity from top of atrium
• Use smoke curtains and glass corner barriers to:
– Minimize atrium volume
– Minimize smoke movement/leakage onto egress balconies
• Limit potential fire size at the 1st Floor
• Provide early detection
– Beam smoke detectors for upper atrium
– Flame (UV/IR) detectors for the 1st Floor
Smoke Curtains
•
Automatic, electrically operated
•
Forms a continuous barrier
against smoke movement
•
Gravity “fail safe” operation
•
Two stage deployment option
•
UL Listed
•
•
UL 10D Fire & Smoke
Curtains
UL 864 Control Accessories
for Fire Alarm Systems
Glass
Corner
Barriers
Smoke
Curtains
Atrium
Smoke Curtain and Glass Corner Locations
Typical floors 2 - 9
Smoke
Curtain
Housing
Deployed
Smoke
Curtain
Smoke Curtain at Floors 2 - 8
Sectional view along balcony
Glass
Canopy
Smoke
Curtain
Housing
Deployed
Smoke
Curtain
Smoke Curtain with Canopy at Floor 9
Sectional view along balcony
Glass
Corner
Barrier
Deployed
Smoke
Curtain
Interferences at Corners
Glass corner barriers provided at Floors 2 – 8 to limit gaps
Smoke Exhaust System
Twelve smoke exhaust fans with total capacity of 48,000 CFM.
Smoke Exhaust System
Four exhaust points on three sides (North, East and West)
Beam Smoke Detection
Early detection of smoke.
Flame Detection
Rapid detection of fire with flame detectors at the 1st Floor.
Smoke Exhaust
System Make-Up Air
•
Make-up air enters at the 1st
Floor through louvers on the
West side and via the main
entrance doors.
•
All make-up air components to
be automatically activated by
the fire alarm system.
•
Louvers
A minimum of 180 square feet
of free area is provided.
Main Entrance
Doors
Smoke and Egress Models
• Demonstrate that the design meets the intent of
Section 909 of the 2008 New York City Building
Code.
• Demonstrate that a tenable environment is provided
for evacuation of occupants from the atrium.
• Fire Dynamic Simulator (FDS) version 5.3.2,
Smokeview and Pathfinder 2011TM
Applicable Codes & Standards
• Applicable Code
– 2008 New York City Building Code
• Other Referenced Standards
– NFPA 92B, Standard for Smoke Management Systems in
Malls, Atriums, and Large Spaces, 2009 Edition
– International Building Code, 2009 Edition
Applicable Codes & Standards
• All portions of an atrium smoke exhaust system are
required to be capable of continued operation for a
minimum of 20 minutes. (2008 NYCBC 909.4.6)
• A time of tenability to be maintained for 1.5 times a
calculated egress time or 20 minutes, whichever is
less. (IBC 909.4.6)
• When the design is based on occupants exiting a
building, a timed egress analysis should be
conducted. (NFPA 92B 4.5.3.3)
Tenability Criteria
• Visibility
– The measured distance an occupant can see through smoke
• Temperature
– The higher temperatures that may be present due to a fire
• Carbon Monoxide Concentration
– The concentration of carbon monoxide that may be present
due to a fire
Tenability Criteria
Measured at 6 feet above the walking surface of the means of egress.
Tenability Parameter
Performance Criteria
Visibility2
33 ft (10 m)
Occupant Exposure Temperature1
140 F (60 C)
Carbon Monoxide Concentration1
1000 ppm
o
o
1. David A. Purser, “Assessment of Hazards to Occupants from Smoke, Toxic Gases, and Heat” SFPE Handbook, 4th
Edition
2. G.V. Hadjisophocleous, N. Benichou, and A.S. Tamin, “Literature Review of Performance-Based Fire Codes and
Design Environment,” Journal of Fire Protection Engineering, 9(1), 1998, pp12-40.
Design Fire Scenarios
• Two Severe Case Scenarios
– 1st Floor below the atrium opening (not sprinkler protected)
– 1st Floor restaurant bar (sprinkler protected with 15.57 feet
ceiling height)
• Anticipated Fuel Load
–
–
–
–
Seating complying with CAL-TB 133
Dining tables
Restaurant furnishings (e.g., pillows)
Wood bar
Design Fire Scenarios
• No large fuel loads anticipated on Floors 2 – 9 of
atrium since balconies are part of the means of
egress.
– Assumes balconies kept clear as means of egress
– Housekeeping cart may be present at times, but balconies
are sprinkler protected (less severe case)
CAL-TB 133
• California Technical Bulletin 133 (CAL-TB 133)
– Full scale test of the entire seating piece.
– Each piece of furniture is listed as an entire assembly.
• During the test, the furnishing cannot:
–
–
–
–
Exceed 80 kW maximum heat release rate at any point
Exceed 25 MJ total heat release rate in first 10 minutes
Exceed 75% opacity at any point within 4 feet
Exceed 1,000 ppm carbon monoxide concentration
Design Fire Scenario 1
•
•
•
Fire located under atrium
opening
Not sprinkler protected
CAL TB 133 furniture, table and
pillows
Fuel Package
Cal TB133 seating
furniture
Wood table w/ metal
legs (area 10sqft)
Total = 2,000 kW
Peak Heat
Release Rate
80 kW
250 kW
3 Tables = 750 kW
8 Chairs = 640 kW
Miscellaneous Furnishings = 200 kW
Conservative Addition of 400 kW
Design Fire Scenario 2
•
•
•
Fire located at restaurant bar
area
Sprinkler protected
CAL TB 133 furniture, wood bar
and miscellaneous items
Fuel Package
Cal TB133 seating
furniture
Wooden desk
(2 ft by 4 ft by 2.6 ft)
Total = 2,600 kW
Peak Heat
Release Rate
80 kW
650 kW
Bar (2 x Desks) = 1,300 kW
8 Bar Chairs = 640 kW
Miscellaneous Items = 250 kW
Conservative Addition of 410 kW
Analysis of Models
• Timed egress analysis using Pathfinder
(Thunderhead Engineering)
• Two Severe Case Design Fire Scenarios using Fire
Dynamics Simulator (FDS) (National Institute of
Standards and Technology)
• Compare results to ensure tenable environment is
maintained for required egress time.
Egress Model Results
•
Fire Detection
•
•
•
Occupant Notification
•
•
10 seconds (NFPA 72)
Occupant Pre-Movement Delay
•
•
•
•
Fire Scenario 1 = 20 seconds
Fire Scenario 2 = 50 seconds
Perception, Interpretation and
Action
240 seconds
SFPE Handbook, 3rd Edition,
Table 3-13.1
Occupant Movement
•
Pathfinder results
SFPE Handbook, 3rd Edition
Occupant Load
•
2 guests per single guest room
•
4 guests per double guest room
•
4 guests per suite
•
2 guests per accessible guest
room
•
15 sqft per person for 2nd Floor
conference room
Minimum Required
Safe Egress Times
Time Element
(sec)
•
•
•
Scenario 1 detection time
established based on flame
detector response.
Scenario 2 detection time based
on quick response sprinkler
activation (smoke detectors will
activate more quickly).
Total evacuation time includes
time to reach exit stairs.
Occupants will be out of the
atrium sooner.
Design Fire
Scenario 1
Design Fire
Scenario 2
Ignition
0
0
Detection
20
50
Fire Alarm
Processing
10
10
Occupant
Delay
240
240
Occupant
Movement
140
140
Minimum
Evacuation
410
440
Safety Factor
1.5
1.5
Total
Evacuation
615
660
Design Fire Scenario 1
Temperature Elevation
at 615 seconds
Temperature Floor 9
at 615 seconds
Access
Stair
Elevator
Lobby
Egress
Balconies
Design Fire Scenario 1
Carbon Monoxide
Elevation at 615 seconds
Design Fire Scenario 1
Visibility Floor 9
at 615 seconds
Visibility Floor 8
at 615 seconds
Access
Stair
Elevator
Lobby
Egress
Balconies
Design Fire Scenario 1
Visibility Floor 2 – 7
at 615 seconds
Access
Stair
Elevator
Lobby
Egress
Balconies
Design Fire Scenario 1
Results
• None of the tenability thresholds was exceeded in the
means of egress during the required safe egress time
of 615 seconds (10.25 minutes).
• A sensitivity analysis, including winter and summer
scenarios, indicating no significant differences in
performance.
Design Fire Scenario 2
Temperature Elevation
at 660 seconds
Temperature Floor 9
at 660 seconds
Access
Stair
Elevator
Lobby
Egress
Balconies
Design Fire Scenario 2
Carbon Monoxide
Elevation at 660 seconds
Design Fire Scenario 2
Visibility Floor 9
at 660 seconds
Access
Stair
Elevator
Lobby
23 feet to
atrium exit
Egress
Balconies
Design Fire Scenario 2
Visibility Floor 8
at 660 seconds
Access
Stair
Elevator
Lobby
Egress
Balconies
Design Fire Scenario 2
Visibility Floors 2 – 7
at 660 seconds
Access
Stair
Elevator
Lobby
Egress
Balconies
Design Fire Scenario 2
Results
• The tenability thresholds for temperature and carbon
monoxide concentration were not exceeded in the
means of egress during the required safe egress time
of 660 seconds (11 minutes).
• The visibility threshold was exceeded on the 9th and
8th Floors, where additional exit signage will be
provided along the egress balcony.
Design Fire Scenario 2
Results
• The visibility threshold at the access stair / elevator
lobby is exceeded as they are within the atrium.
– Automatic smoke curtains will be provided with signage;
– Automatic smoke curtains are within the visibility distance
available at the end of 660 seconds (11 min);
– Time to egress from this area will be less than 30 seconds.
• A sensitivity analysis, including winter and summer
scenarios, indicating no significant differences in
performance.
Summary
Tenability
Parameter
Performance
Criteria
Design Fire
Scenario 1
Design Fire
Scenario 2
Pass
Pass
w/additional
signage
Visibility
33 ft (10 m)
Occupant
Exposure
Temperature
140 F (60 C)
Pass
Pass
Carbon
Monoxide
Concentration
1000 ppm
Pass
Pass
o
o
Thank You!
Presentation of a Case Study
EGRESS AND SMOKE MOVEMENT
MODELING AT
5 BEEKMAN STREET
for the
New Jersey Chapter
Society of Fire Protection Engineers
September 9, 2013