tower smoke management

8/10/2019 Tower Smoke Management

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Tower Smoke Management -

System Planning, Design &

Testing

Kirk Rosenbaum, CCP, PQPSenior Commissioning ManagerKEO International Consultants


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INTRODUCTIONKirk Rosenbaum, CCP, PQP

Senior Commissioning Manager

30 + Years Experience in Design,

Construction Industry

12 + Years Experience Exclusively

in the Area of Commissioning

10 + Years Experience in Fire Life

Safety Review and Inspection

Managed the Commissioning of

Over 2,500,000 m2 of new buildingsand 250,000 m2 of existing

buildings

Former Director and Treasurer of

the Building Commissioning

Association


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Need for Tower Smoke Management

Sample GCC Tower Fire Events 2012


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Code & Standard Design Requirements

NFPA 922012;Standard for Smoke Control Systems

5.2.1 Pressure differential across smoke barriers shall be 12.5 Pa for fullysprinklered buildings.

5.2.2 Pressure differential across doors shall not cause the force required to open

the doors to exceed 133 N.

5.3 Stairways are to be pressurized to a minimum of 12.5 Pa and a maximum levelthat causes door opening forces to be less than 133 N.

5.4 Elevators shall be considered a separate smoke zone when smoke control isrequired.

5.3.5.1 Vestibules shall not be required, but shall be permitted as part of a building

smoke management system.


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Qatar Civil DefenseFire Safety Standards

FSS 2.2.13 Smoke Stop or Fire Fighting Lobby required when:(i) Stairway has no natural light or ventilation, or(ii) Stairway traverses more than 4 stories (incl. basements), or(iii) Has a habitable height more than 28 meters above Ground.

All Fire Fighting Lifts shall be provided with a Fire Fighting Lobby.

Mechanical Ventilation/Pressurization to be provided at 10 Air Changes per Hour(ACH).

Mechanical equipment is to be provided with 100% stand-by power.

Smoke Stop Lobbies shall be no less than 3 square meters in area.Fire Fighting Lobbies shall be no less than 6 square meters in area with nodimension less than 2 meters.


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FSS 2.2.13 Basements exceeding one story in depth require a Smoke Stop Lobbyadjacent to the Fire Fighting Lift and its adjacent stairway only. Other basementstairways do not require Smoke Stop Lobbies.

FSS 6.6.3

Fire Lift required when building habitable height exceeds 23 metersabove ground level or 9 meters below ground level.

FSS 1.5 A high-rise building exceeding 30 storeys shall be provided with refugefloors at an interval not exceeding 20 storeys.

A high-rise building exceeding 30 storeys shall be provided with refuge floors at aninterval not exceeding 20 storeys.

A minimum of 50% of the gross floor area of the Refuge Floor must be a protectedHolding Area.


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FSS 1.5 The Holding Area is to be ventilated:(ii) Naturally ventilation requires the total area of the ventilation openings to not

be less than 25% of the gross floor area of the Holding Area.(iii) Mechanical ventilation is also acceptable as long as the equipment is powered

via 2-hour fire rated cables and 100% stand-by power is available.


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Low-RiseBuilding

< 23 metersabove ground

< 9 metersbelow ground

No smokemgmt system

required


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Low-Rise Bldg

w/ Deep

Basement < 23 meters

above ground

> 9 metersbelow ground

Fire LiftRequired

Bsmt StairPressurizationRequired


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Mid-RiseBuilding

> 23 metersabove ground

> 9 metersbelow ground

Fire LiftRequired

Bsmt & Tower

Stairs RequirePressurization


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High-Rise Bldgw/ Refuge Floor

> 30 storeysabove ground > 9 meters

below ground

Fire LiftRequired

Evacuation Liftmay be required

Bsmt Stairs,Tower Stairs,and RefugeRequire

Pressurization


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High-Rise Bldgw/ Fire FloorIsolation

Same physicalfeatures asHigh-Rise

In addition tostandard High-Rise smokemgmt, two

floors aboveand below thefire floor arepressurized.


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Typical Floor Plan (No Fire Floor Isolation)


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Pressurized Floor (Fire Floor Isolation)


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Typical Floor Plan (Fire Floor Isolation)


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Code & Standard System Sizing MethodRecommendation and Test Requirements

Document NFPA 92 - 2012 Qatar Civil Defense - FSS

System SizingMethodRecommendation

SFPE TR 82-4 Designing StairPressurization Systems(Similar to British StandardMethod)

ASHRAE Chapter 52 Fire andSmoke Management

None Provided

System TestRequirement

Maintain pressure differentialacross closed doors when(1) 3* Stairway Doors are

open, or(2) Lifts parked with doors

open.

None Provided

* The number of open stairway doors is determined by the local fire authority and is

not NFPA prescribed.


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Calculation ASHRAE 52

QSP= 0.839 * Asb* (Delta-Psb)1/2 + 0.452 * AOD* (Delta-Psb)

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QSP =Fan Flow Rate for Pressurization of Stairway toRequired Static Pressure (m3/s)

HS = Total Heightof Stairway

Asb =Total Flow Area between Stairway and Building (m2) -walls and closed doors

AOD =Flow Area through

Open Doors (m2)Delta -Psb =

Primary Pressure Difference betweenStairway & Building (Pa)


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Calculations Industry Leakage Data

ASHRAE HANDBOOK 2007Chapter 52

Field tests haverepeatedlyshown thatLOOSE wall

constructionshould beutilized for

system sizing inthe region.


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SelectDoors

asAppropriate

fortheProject

(Blue

BoxCanBeIgnored)


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Important Note: If a stairway has a door with double-leafs,BOTHleaves of the door must be open for testing and it

only counts as One Door Open.


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Data from a Tamura and Shaw Study, 1976


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Typical SystemLayout

Air InjectionPoints

Single pointinjection OK forlifts to approx.40 storeys

Single pointinjection OK forstairways of

approx. 15 to 20storeys, but willnot satisfy BsmtStairways


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RecommendedSystem Layout

Air InjectionPoints

Inject air to LiftShafts at top,bottom, andapproximatelyevery 40 storeys

Inject air tostairways at topand approximatelyevery 15-20 storeys

Inject air to allbasementstairways


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Lessons Learned (Page 1 of 5)

Pressurization systems to be sized based onASHRAE 52 methodology with loose leakage rates

and appropriate safety factors.

Stack effect is negligible based on field test results and

may generally be discounted in system sizing

calculation.

Wind effects are negligible based on field testing and

may generally be discounted in system sizingcalculation unless stairways or lift shafts are located

against an exterior wall.


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Pressurization system intakes and reliefs should not bedirectly exposed to wind pressure and need to have

tightly sealing dampers. Either condition may allow

humid outside air to enter a stairway or shaft and

could result in mould issues.

Masonry shafts are not appropriate as air plenums for

pressurization systems; excessive leakage and

excessive friction loss.

For towers taller than 40 storeys single point air

injection at the top of the building is generally

insufficient for pressurizing lift shafts.


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Pressurization system fans should be equipped withVFDs for the setting of fan maximum speed.

Pressurization systems should be equipped with

adjustable pressure relief dampers to prevent system

over-pressurization of stairways. Pressure sensor

control may have excessive response time.

Basement stairs should be equipped with stand-alone

pressurization systems and not combined with towerpressurization systems.


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Pressurization system fans should be equipped with

VFDs for the setting of fan maximum speed.

Pressurization systems should be equipped with

adjustable pressure relief dampers to prevent system

over-pressurization of stairways. Pressure sensorcontrol may have excessive response time.

Basement stairs should be equipped with stand-alone

pressurization systems and not combined with tower

pressurization systems.

For towers taller than 15 - 20 storeys single point air

injection at the top of the building is generally

insufficient for pressurizing stairways.


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Construction schedules should prioritize early

completion of pressurization systems and the executionof pressurization system testing. (Failure to validate

the systems early could result in extensive delays

to the approval for occupancy for the project.)


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Questions & Answers

Kirk Rosenbaum, CCP, PQPSenior Commissioning ManagerKEO International Consultants

Contact Information:PO Box 27594Abu Dhabi, UAE

+974 050 [email protected]

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