Fire Protection Analysis: Dell Academic Building

Fire Protection Analysis: Dell Academic Building

Culminating Experience ProjectFPE 596David Gramlich

Agenda• Applicable Codes and Standards• Building Overview• Occupancy Classification• Construction Type• Structural Requirements• Emergency Power• Occupant Loading• Fire Alarm• Fire Protection• Performance Based Design: Egress Analysis• Performance Based Design: FDS Modeling• Questions

Applicable Codes and Standards

• Life Safety Code, NFPA 101, 2012 Edition (LSC)• International Building Code, 2012 Edition (IBC)• University of Texas System’s Owner’s Design

Guidelines (UT Design)• University of Texas Austin Construction

Standards (UT Standards)

Dell Academic Building

Dell Academic Building

Dell Academic Building Site Plan

Dell Academic Building Interior

Building Overview• Analysis performed at a “snapshot” of 95% Design

Development Stage (DD) (Building currently in CD Phase)

• 6 story medical administration and classroom building Square Footage:▫ Level 1: 15,611 sq.ft. ▫ Level 1.5: 4,572 sq.ft.▫ Level 2: 15,228 sq.ft. ▫ Level 3: 15,537 sq.ft. ▫ Level 4: 15,421 sq.ft. ▫ Level 5: 13,530 sq.ft. ▫ Penthouse: 7,617 sq.ft.

• Building contains 5 story Atrium• Fully sprinklered• Mixed use non-separated

Occupancy Classification• Assembly▫ Group A-2 (IBC §303.1)▫ Assembly (LSC §6.1.2.1)

• Business ▫ Group B (IBC §304.1)▫ Business (LSC §6.1.11.1)

• Storage ▫ Group S-2 (IBC §311.1)▫ Storage (LSC §6.1.13.1)

Construction Classification

• Minimum Construction Type:▫ Type IB (IBC Table 503) Maximum Height Allowed: 180 Feet Maximum Number of Stories: 12 Stories Maximum Allowable Area: Unlimited

▫ Type 222 is the minimum construction type per LSC § 12.1.6. However, the IBC was used.

Structural RequirementsStructural Member IBC Requirement

(IB)LSC Requirement (222)

Structural Frame 2-hours (Table 601.a) 2-hours (A.8.2.1.2)

Floors – Floor/Ceiling 2-hour (Table 601) 2-hours (A.8.2.1.2)

Roofs – Roof/Ceiling 1-hour (Table 601) 1-hour (A.8.2.1.2)

Shaft Enclosures* 2-hours (713.4) 2-hours (6.6.5.1)

Stairways* 2-hours (1009.3.1.2) 2-hours (7.1.3.2.1)

Atrium Separation** 1-hour (404.6) 1-hour (8.6.7)

Electrical Rooms with transformers > 112.5 kVa

1-hour (NFPA 70 §450.21.b)

Fire Pump Room 1-hour (NFPA 20 §5.12.1.1.2)

Fire Command Center 1-hour (§911.1.2)

*No less than the assembly penetrated**Closely spaced sprinklered glass may be used in lieu of a 1-hour fire barrier if glass forms smoke partition per IBC 404.6 Exception and LSC §8.6.7

Opening Protective RequirementsDoor Rating Requirement

IBC Requirement LSC Requirement

2-hour fire barrier 1 ½ hour (Table 716.5) 1 ½ hour (Table 8.3.4.2)

2-hour shaft 1 ½ hour (Table 716.5) 1 ½ hour (Table 8.3.4.2)

1-hour fire barrier ¾ hour (Table 716.5) ¾ hour (Table 8.3.4.2)

In lieu of fire barrier closely spaced sprinklered glass may be used. Doors in these glass barriers must be automatic-closing and must be installed in gasketed frames in a manner that the framing system does not obstruct the sprinkler protection per IBC §404.6 and LSC §8.6.7.

Emergency Power• Emergency Power required for illumination, fire

pump, smoke control system & fire alarm• Building is powered from two separate reliable

power grids in lieu of an emergency power supply system located on site.

• 1st grid is supplied from campus CUP. • 2nd grid is supplied from public grid.• Each grid independently connected to the building. • Automatic transfer switches within the switchgear

located on site transfer power between the two grids in the event of power failure.

Egress: Travel Distances

AssemblyComponent*

LSC Requirement (Table 1016.2)

Maximum AllowableTravel

250 ft.

Common Path (50 or more occupants)

20 ft.

Common Path 75 ft.

Dead End 20 ft.

*Mixed Use nonseparated; assembly maximum travel distances are used throughout these floors.

BusinessComponent

LSC Requirement (Table 1016.2)

Maximum Allowable Travel

300 ft.

Common Path 100 ft.

Dead End 50 ft.

Levels 1, 4 & 5 (Contain assembly) Levels 1.5, 2, 3 (No assembly)

Egress: Occupant Loading Factors & Egress Capacity

Use Occupant Loading Factor (OLF)

Assembly (Fixed Seating) Fixed

Assembly (Less Concentrated)

15 sq.ft./occupant net

Business 100 sq.ft./occupant gross

Kitchen **200 sq.ft./occupant gross

Storage/Mechanical **300 sq.ft./occupant gross

Locker Rooms *50 sq.ft./occupant net

Laboratories *50 sq.ft./occupant net

*OLF per LSC Table 7.3.1.2**OLF per IBC Table 1004.1.2

Egress Component Capacity (in./person)

Doors & Corridors .2

Stair .3

LSC Table 7.3.3.1

Occupant Loading Level 1

Occupant Loading Level 1Group Area (sq.ft.) OLF (sq.ft/occupant) Occupants

Fixed Seating 2225 N/A 90

Assembly 2301 15 154

Business 7552 100 86

Kitchen 325 200 2

Storage/Mech. 3209 300 15

Totals 15611 347

Component Door Width (Effective)

Capacity Factor Capacity Total Used

Door #1 136” 0.2 680 88

Door #2 68” 0.2 340 86

Door #3 34” 0.2 170 86

Door #4 68” 0.2 340 87

Totals 1530 347

Occupant Loading Level 1.5

Occupant Loading Level 1.5Group Area (sq.ft.) OLF (sq.ft/occupant) Occupants

Business 908 100 12


Totals 4572 31

Component Door Width(Effective)

Capacity Factor Capacity TotalUsed

Door #1 68” 0.2 340 21

Stair #1 44” 0.3 146 10

Stair #2 44” 0.3 146 0

Totals 632 31



Business 13927 100 176


Totals 15228 185

Component Stair Width(Effective)


Stair #1 44” 0.3 146 92

Stair #2 44” 0.3 146 93

Totals 292 185



Business 14809 100 169


Totals 15537 176



Stair #1 44” 0.3 146 88

Stair #2 44” 0.3 146 88

Totals 292 176



Assembly (Fixed)

769 N/A 49

Laboratories 3487 50 73

Locker Rooms 333 50 8

Business 9964 100 115


Totals 15421 253



Stair #1 44” 0.3 146 126

Stair #2 44” 0.3 146 127

Totals 292 253



Assembly 935 15 63

Business 12142 100 143


Totals 13530 210



Stair #1 44” 0.3 146 105

Stair #2 44” 0.3 146 105

Totals 292 210

Occupant Loading Penthouse

Occupant Loading PenthouseGroup Area (sq.ft.) OLF (sq.ft/occupant) Occupants

Business 570 100 7


Totals 7617 34

Component Stair Width (Effective)


Stair #1 44” 0.3 146 17

Stair #2 44” 0.3 146 17

Totals 292 34

Fire Alarm System Requirements• A manual fire alarm system and automatic fire detection is required

in accordance with NFPA 72 (IBC §907.2.6 & UT Design)• Manual pull stations provided within 5 ft. of exits. • Emergency Communication System (ECS) required and provided at

Fire Alarm Control Panel (FACP) (IBC 907.2.13) • Fire Department Radios to be used in lieu of Fire Fighter Phone

Jacks (UT Design Standard)• General Alarm Panel provided at building main entrance (UT Design

Standard)• Heat detection provided in Elevator Machine Room• Smoke detection must be installed in the following locations (IBC

907.2.18.1):▫ Main supply duct with fans greater than 2,000 CFM , return air

plenum, and ducts serving two or more stories▫ Mechanical and Electrical Rooms▫ Atrium (IBC 907.2.14)▫ Elevator Lobbies

Example Fire Alarm System Layout Level 1

Fire Protection Systems Code Requirements• Automatic Sprinkler System Required (IBC

903.3.1.1 & IBC §404.3)• Class 1 Combination Standpipe System provided

at floor landings (IBC 905.3.1). • Building contains two risers.• Standpipe demand: 750 gpm total demand at

100 psi (500 gpm at most remote riser & 250 gpm for the additonal riser per NFPA 14).

Atrium Sprinkler Zone• Atrium is a separate sprinkler zone from remainder

of building for smoke control system activation. • Zone separation is performed with separate

waterflow switch at riser location.• Atrium glass separation is required to be sprinklered

with closely spaced sprinklers in accordance with IBC §404.6 Exception 1 and NFPA 13 §8.15.4. Sprinklers must be within 4-12 inches off glass at intervals no greater than 6 ft on the walking side.

• Sprinklers must have a maximum RTI of 50 m½s½

(quick response) in accordance with DETACT analysis.

Sprinkler System Riser Diagram

Sprinkler System Design• Quick Response Sprinklers provided throughout

and utilize remote area reduction in accordance with NFPA 13 Figure 11.2.3.2.3.1.

Rooms Hazard Classification

Density and Remote Area

Offices & Circulation

Light Hazard .1 gpm/sq.ft. over a 945 sq.ft. design area

Mech./Elec./Storage and Labs

Ordinary Hazard (Group 1)

.15 gpm/sq.ft. over a 945 sq.ft. design area

Fire Pump Requirements• Backflow prevention accomplished with double

check valve assembly in a vault exterior to building. • Standpipe demand calculated as 784 GPM @ 164.6

psi with HASS. This exceeds estimated sprinkler demand.

• Water Supply: 84.6 PSI Static, 81.6 Residual @ 1247 GPM flow.

• 750 GPM @ 100 PSI boost fire pump required. • Fire Pump specified as electric horizontal-split case.• PRV used at pump outlet to regulate pressures

under 175 psi.

Sprinkler System One-Line Diagram

Sprinkler System & Atrium Limits 1st

Floor

Sprinkler System & Atrium Limits 2nd

Floor

Sprinkler System and Atrium Limits 3rd

Floor

Sprinkler System and Atrium Limits 4th

Floor

Sprinkler System and Atrium Limits 5th

Floor

Sprinkler System and Atrium Limits Penthouse

Performance Based Design Smoke Control System

• FDS Modeling used to support smoke control system design.

• LSC §8.6.7 requires smoke control system to maintain tenable conditions for 20 minutes or 1.5 calculated egress time whichever is greater.

• Tenable conditions must be maintained a minimum of 6 ft. above the walking surface per LSC §8.6.7 .

Timed Egress Analysis

• ASET > RSET• Tenable conditions must be provided for 1.5 x

calculated egress time or 20 minutes whichever is greater per LSC §8.6.7.

• tRSET = required safe egress time• Δtdet = detection time • Δta = alarm time • Δtpre = premovement time• Δttrav = travel time

Alarm, Detection and Premovement• (Δtdet ) The detection time is assumed to be the time for sprinkler

activation of 198 seconds (3.3 minutes). • (Δta) According to the National Fire Alarm Code, NFPA 72, 2007

edition, activation of initiating devices are required to occur within 90 seconds of a water flow (NFPA72 §5.11.2). NFPA 72 prescribes that the delay to occupant notification from the time of initiating signal is to be 10 seconds (NFPA72 §6.8.1.1). A value of 100 seconds (1.67 minutes) was used in this analysis as the delay from detection to occupant notification.

• (Δtpre ) Premovement time was estimated to be 60 seconds (1 minute) for familiar, awake, office buildings with voice communication in accordance with SFPE Handbook 4th Edition Table 3-12.2.

• Total time before occupant movement is 358 seconds (5.97 minutes).

Travel Time• Δttrav calculated utilizing SFPE 4th Edition Hand

Calculations. • Assumptions: ▫ Open stair within Atrium not utilized as portion of

means of egress.▫ All occupant walking speed to exit assumed to be 155

ft./min. (with locomotion disability SFPE Handbook 4th Edition Table 3-12.4).

▫ All occupant walking speed down stair assumed to be 212 ft./min. (disabled occupants use stair as an area of refuge).

▫ Occupants begin movement at the same time.▫ Stairs are filled simultaneously.

Maximum Travel Time to Reach Exits

Travel time evaluated at 155 ft./min.

Level Exit No. Maximum Travel Distance (ft.)

Travel Time (min.)

1

1 119 0.772 177 1.143 63 0.414 118 0.76

1.5Door 112 0.72

Stair No. 1 64 0.41

2Stair No. 1 191 1.23Stair No. 2 144 0.93

3Stair No. 1 205 1.32Stair No. 2 160 1.03

4Stair No. 1 134 0.86Stair No. 2 124 0.80

5Stair No. 1 150 0.97Stair No. 2 150 0.97

PHStair No. 1 100 0.65Stair No. 2 100 0.65

Stair #1-Exit No.4 4 36 0.23

Stair #2- Exit No. 1 1 78 .50

Passage Time through Egress Components

• Fs = (1-αD)kD• tp = P/ (FsWe)

▫ tp = time for passage in min.▫ α = 2.86 for speed in ft./min.▫ D = density in people per sq.ft. (.3 max for crush)▫ k = 275 for doorways and corridors; 212 for stairways with 7

in. risers and 11 in. treads▫ We = effective width in feet (minus 12 in. for boundary

layer)▫ Fsm = maximum value for corridors and doorways is 24

occ./min/ft; maximum value for 7/11 stairways is 18.5 occ./min/ft

Total Egress Times Ground Levels

Floor Exit No. Occupantstp -Exit Access Corridor (min)

tp -Exit Doorways

(min)

tp -Governing

Passage Time (min)

1

1 88 1.20 1.20 1.20

2 86 0.27 0.77 0.77

3 86 0.46 1.96 1.96

4 87 1.20 1.20 1.20

1.5 Door 21 0.29 0.29 .29

Queuing Locations

Total Egress Time Upper Floors• 34-inch stair discharge doors govern time

passage through stair at maximum flow of 24/person/min/ft. (44 persons/min).

Stairway Occupant Load Time To Discharge (min.)

Stair No. 1 438 9.95

Stair No. 2 430 9.77

Total Egress Analysis

Floor Exit tdet ta tpre 1.5 * (ttrav) RSET

1

1

3.3 1.67 1

1.5*(.77+1.20)=2.35 8.32

2 1.5*(1.14+.77)=2.48 8.45

3 1.5*(.41+1.96)=3.56 9.53

4 1.5*(1.20+.76)=2.56 8.53

1.5 Door 1.5*(.72+.29)=1.37 7.34

1.5-PH

S1* 1.5*(1.32+9.95+.23)=16.25 23.22S2* 1.5*(1.03+9.97+.5)=16.68 23.22

*Assume floor with largest travel time receives last priority into the stair and out of the discharge door. This is the 3rd Level.

FDS Modeling Tenability

Tenability Criteria Metric Units English Units

Visibility 10 meters 33 feet

Temperature 60°C 140°F

Toxicity (CO) 1000 ppm 1000 ppm

FDS Modeling Design Fire Scenarios

• Assumed maximum fuel loads to be graduate displays within atrium (kiosks)

• NISTIR 6030 provides data for burning of Kiosks (6.9 ft high x 13 sq.ft.)

• Burning of “open” kiosk has maximum HRR of 1750 kW per Kiosk

• Conservatively estimated as a “fast” growing fire

FDS Design Fire Scenario #1• 5.25 MW Axisymmetrical Fire (three kiosks)• “fast” growing fire• Maximum HRR to be maintained throughout

duration of model • Materials burned a conservative mixture of

plastic, wood and foam with the following properties:

Property Value

Heat of Combustion 20,000 kJ/kg

Soot Yield .05 g/g

CO Yield .05 g/g

0

1000

2000

3000

4000

5000

6000

0 200 400 600 800 1000 1200

HRR (kW)

time (s)

Design Fire Scenario #1

FDS Design Fire Scenario #2• 5.25 MW Balcony Spill Plume Condition on Level 1• DETACT Model showing sprinkler activation at

1,840 kW at 198 seconds.• DETACT: Ceiling height was set to 24.6 feet for the

first floor and RTI of the sprinkler was set at 50 m½s½.

• Assume sprinkler control but not extinguish.• HRR at sprinkler activation is to be maintained

throughout duration of model. • Same fuel properties as Scenario #1

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 200 400 600 800 1000 1200

HRR (kW)

time (s)

Design Fire Scenario #2 & #3

Fire Design Scenario #1 & #2 Locations

Scenario #2Scenario #1

NFPA 92B Hand Calculation Estimation

Fire Design Scenario NFPA 92B HandCalculations Exhaust Rate

Fire Scenario #1 (Axisymmetrical)

370,000 CFM

Fire Scenario #2 (Balcony Spill Plume)*

335,000 CFM

*Width of the plume (W) assumed to be half the height of the ceiling (12 ft.).

FDS Model

• Modeled Exhaust CFM 710,000 (maximum due to makeup air openings)• Makeup 2,485 sq.ft. of openings (estimated 246 ft./min. through

openings)

Fire Design Scenario #1 Results

Fire Design Scenario #1 Temperature

Fire Design Scenario #1 Visibility

Fire Design Scenario #1 CO Concentration

.001 mol/mol of Carbon Monoxide = 1,000 ppm

Fire Design Scenario #1 Velocities




FDS Design Fire Scenario #3

• Same as Scenario #2 however, the effect of placing the fire on Level 2 is observed.

• Scenario performed in order to eliminate the effect of any smoke allowed to escape makeup air opening.

• Same fuel properties as all scenarios.

Fire Design Scenario #3 Location




Conclusions• Recommend separating corridors on Levels 2, 3,

4 & 5 from atrium to prevent smoke entrainment of those spaces.

• Egress should not be allowed down grand stair case due to increased velocities.

• Rerun scenarios in order to reduce CFM after corridors are separated.

• One of the exit stairs must discharge directly to the exterior.

Questions?

Fire Protection Analysis: Dell Academic Building

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