tower smoke management - system planning, … smoke management - system planning, design &...

Tower Smoke Management - System Planning, Design & Testing

Kirk Rosenbaum, CCP, PQP Senior Commissioning Manager KEO International Consultants

INTRODUCTION Kirk 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 buildings

and 250,000 m2 of existing

buildings

• Former Director and Treasurer of

the Building Commissioning

Association

Need for Tower Smoke Management

Sample GCC Tower Fire Events 2012

Code & Standard Design Requirements

NFPA 92 – 2012;

Standard for Smoke Control Systems

5.2.1 – Pressure differential across smoke barriers shall be 12.5 Pa for fully sprinklered 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 level that causes door opening forces to be less than 133 N. 5.4 – Elevators shall be considered a separate smoke zone when smoke control is required. 5.3.5.1 – Vestibules shall not be required, but shall be permitted as part of a building smoke management system.


Qatar Civil Defense

Fire 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 no dimension less than 2 meters.


Qatar Civil Defense


FSS 2.2.13 – Basements exceeding one story in depth require a Smoke Stop Lobby adjacent to the Fire Fighting Lift and its adjacent stairway only. Other basement stairways do not require Smoke Stop Lobbies. FSS 6.6.3 – Fire Lift required when building habitable height exceeds 23 meters above ground level or 9 meters below ground level. FSS 1.5 – A high-rise building exceeding 30 storeys shall be provided with refuge floors at an interval not exceeding 20 storeys. A high-rise building exceeding 30 storeys shall be provided with refuge floors at an interval not exceeding 20 storeys. A minimum of 50% of the gross floor area of the Refuge Floor must be a protected Holding Area.


Qatar Civil Defense


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.

Low-Rise Building

• < 23 meters above ground

• < 9 meters below ground

• No smoke mgmt system required

Low-Rise Bldg w/ Deep Basement

• < 23 meters above ground

• > 9 meters below ground

• Fire Lift Required

• Bsmt Stair Pressurization Required

Mid-Rise Building

• > 23 meters above ground



• Bsmt & Tower Stairs Require Pressurization

High-Rise Bldg w/ Refuge Floor

• > 30 storeys above ground



• Evacuation Lift may be required

• Bsmt Stairs, Tower Stairs, and Refuge Require Pressurization

High-Rise Bldg w/ Fire Floor Isolation

• Same physical features as High-Rise

• In addition to standard High-Rise smoke mgmt, two floors above and below the fire floor are pressurized.

Typical Floor Plan (No Fire Floor Isolation)

Pressurized Floor (Fire Floor Isolation)

Typical Floor Plan (Fire Floor Isolation)

Code & Standard System Sizing Method Recommendation and Test Requirements

Document NFPA 92 - 2012 Qatar Civil Defense - FSS

System Sizing Method Recommendation

SFPE TR 82-4 Designing Stair Pressurization Systems (Similar to British Standard Method) ASHRAE Chapter 52 – Fire and Smoke Management

None Provided

System Test Requirement

Maintain pressure differential across 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.

Calculation – ASHRAE 52

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

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

HS = Total Height of 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 between Stairway & Building (Pa)

Calculations – Industry Leakage Data

ASHRAE HANDBOOK 2007 Chapter 52

• Field tests have repeatedly shown that ‘LOOSE’ wall construction should be utilized for system sizing in the region.

Calculations – Industry Leakage Data S

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

only counts as One Door Open.


Data from a Tamura and Shaw Study, 1976

Typical System Layout

Air Injection Points

• Single point injection OK for lifts to approx. 40 storeys

• Single point

injection OK for stairways of approx. 15 to 20 storeys, but will not satisfy Bsmt Stairways

Recommended System Layout

Air Injection Points

• Inject air to Lift Shafts at top, bottom, and approximately every 40 storeys

• Inject air to

stairways at top and approximately every 15-20 storeys

• Inject air to all basement stairways

Lessons Learned (Page 1 of 5)

• Pressurization systems to be sized based on

ASHRAE 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 sizing

calculation unless stairways or lift shafts are located

against an exterior wall.


• Pressurization system intakes and reliefs should not be

directly 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.


• 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 sensor

control may have excessive response time.

• Basement stairs should be equipped with stand-alone

pressurization systems and not combined with tower

pressurization systems.


• 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 sensor

control 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.


• Construction schedules should prioritize early

completion of pressurization systems and the execution

of pressurization system testing. (Failure to validate

the systems early could result in extensive delays

to the approval for occupancy for the project.)

Questions & Answers

Kirk Rosenbaum, CCP, PQP Senior Commissioning Manager KEO International Consultants Contact Information: PO Box 27594 Abu Dhabi, UAE +974 050 642-8969 [email protected]

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