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Presentation of a Case StudyEGRESS AND SMOKE MOVEMENT

MODELING AT5 BEEKMAN STREET

for theNew Jersey Chapter

Society of Fire Protection Engineers

September 9, 2013

Introduction1. Building Description2. Project Overview3. Atrium Details4. Atrium Challenges5. Atrium Solutions

6. Smoke & Egress Models7. Applicable Codes & Standards8. Tenability Criteria9. Design Fire Scenarios10. Analysis of Models

Building Description

• 150,000 square feet

• Originally constructed in 1882

• First “fireproof” office building

• Located in historic district

Project OverviewConversion to hotel occupancy with new hotel/residential tower addition.

Original BuildingAnnex

New Tower

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 DetailsFire rating separating the egress balcony from guest rooms

Means of EgressAtrium and guest room egress through 2-hour atrium separation to new exit stairs.

Elevators and Open Stair

Exit Stair

Balcony Walkway

Exit Stair

Atrium

Paths of Egress

2-hr Atrium Separation

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

Smoke Curtain and Glass Corner LocationsTypical floors 2 - 9

Atrium

GlassCorner

Barriers

SmokeCurtains

Smoke Curtain at Floors 2 - 8Sectional view along balcony

SmokeCurtain Housing

Deployed SmokeCurtain

Smoke Curtain with Canopy at Floor 9Sectional view along balcony

SmokeCurtain Housing


Glass Canopy

Interferences at CornersGlass corner barriers provided at Floors 2 – 8 to limit gaps

Glass Corner Barrier


Smoke Exhaust SystemTwelve smoke exhaust fans with total capacity of 48,000 CFM.

Smoke Exhaust SystemFour exhaust points on three sides (North, East and West)

Beam Smoke DetectionEarly detection of smoke.

Flame DetectionRapid 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.

• A minimum of 180 square feet of free area is provided.

Main Entrance Doors

Louvers

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

Tenability Parameter Performance Criteria

Visibility2 33 ft (10 m)

Occupant Exposure Temperature1 140oF (60oC)

Carbon Monoxide Concentration1 1000 ppm

1. David A. Purser, “Assessment of Hazards to Occupants from Smoke, Toxic Gases, and Heat” SFPE Handbook, 4th

Edition2. 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.

Measured at 6 feet above the walking surface of the means of egress.

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

3 Tables = 750 kW8 Chairs = 640 kWMiscellaneous Furnishings = 200 kWConservative Addition of 400 kW

Total = 2,000 kW

Fuel Package Peak Heat Release Rate

Cal TB133 seating furniture

80 kW

Wood table w/ metal legs (area 10sqft)

250 kW

Design Fire Scenario 2• Fire located at restaurant bar

area• Sprinkler protected• CAL TB 133 furniture, wood bar

and miscellaneous items

Bar (2 x Desks) = 1,300 kW8 Bar Chairs = 640 kWMiscellaneous Items = 250 kWConservative Addition of 410 kW

Total = 2,600 kW

Fuel Package Peak Heat Release Rate

Cal TB133 seating furniture

80 kW

Wooden desk (2 ft by 4 ft by 2.6 ft)

650 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

• Fire Scenario 1 = 20 seconds• Fire Scenario 2 = 50 seconds

• Occupant Notification• 10 seconds (NFPA 72)

• Occupant Pre-Movement Delay• 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• 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.

Time Element (sec)

Design Fire Scenario 1


Ignition 0 0Detection 20 50Fire Alarm Processing 10 10

Occupant Delay 240 240

Occupant Movement 140 140

MinimumEvacuation 410 440

Safety Factor 1.5 1.5Total Evacuation 615 660

Design Fire Scenario 1Temperature Elevation

at 615 secondsTemperature Floor 9

at 615 secondsElevator Lobby

Access Stair

Egress Balconies

Design Fire Scenario 1Carbon Monoxide

Elevation at 615 seconds

Design Fire Scenario 1Visibility Floor 9at 615 seconds

Visibility Floor 8at 615 seconds

Elevator Lobby

Access Stair

Egress Balconies

Design Fire Scenario 1Visibility Floor 2 – 7


Access Stair

Egress Balconies

Design Fire Scenario 1Results

• 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 2Temperature Elevation

at 660 secondsTemperature Floor 9


Access Stair

Egress Balconies

Design Fire Scenario 2Carbon Monoxide

Elevation at 660 seconds


Elevator Lobby

Access Stair

Egress Balconies

23 feet to atrium exit


Elevator Lobby

Access Stair

Egress Balconies

Design Fire Scenario 2Visibility Floors 2 – 7

at 660 seconds

Elevator Lobby

Access Stair

Egress Balconies


• 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.


• 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.

SummaryTenability Parameter

Performance Criteria



Visibility 33 ft (10 m) PassPass

w/additional signage

Occupant Exposure

Temperature140oF (60oC) Pass Pass

Carbon Monoxide

Concentration1000 ppm Pass Pass

Thank You!Presentation of a Case Study

EGRESS AND SMOKE MOVEMENT MODELING AT

5 BEEKMAN STREET

for theNew Jersey Chapter

Society of Fire Protection Engineers

September 9, 2013

presentation of a case study egress and smoke … sfpe... · presentation of a case study egress...

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