Sunday, May 25, 2008

Servicing the Burj Dubai

With services risers running the full 600m+ height of the building, designing MEP systems to serve the Burj Dubai has taken great care. How will the tower be serviced? Billed as the tallest building in the world, the task of providing MEP services to the Burj Dubai was always going to be a challenge. The world records made by the Emaar Properties' project stretch to the services themselves, with the longest lift shaft in the world and mechanical operating pressures that would send some MEP consultants into a cold sweat.

Despite this, the mission of providing reliable and efficient MEP services for the tower has involved the use of proven technologies and off-the-shelf products - albeit under a very close and detailed design and installation process and a major logistics programme.

Design considerations

The original design of the MEP services systems was carried out by the Chicago office of international consultant Skidmore, Owings and Merrill (SOM). "They were the original architect, structural engineer and MEP engineer," explains Hyder Consulting Middle East senior mechanical engineer Alastair Mitchell. As supervision consultant for the project Hyder Consulting is jointly responsible for ensuring the correct installation of the MEP services to this design. "As part of or contract with Emaar we have adopted [SOM's] design - this makes us jointly responsible for the design with SOM," adds Mitchell.

With all eyes of the world on the project, ensuring a 100% reliable system in all circumstances is of primary importance. With this in mind, one of the major decisions that was taken at the design stage was to use tried-and-tested products and systems wherever possible. Rather than opt for radical, new technologies a base of solid electrical and mechanical design has been used for the systems, with input from the process and oil and gas industry standards and best practice referred to when the pressures and system sizes grew beyond those of a standard building services project.

"[The MEP system] is quite standard in it's design in that they haven't done anything radically different," confirms Mitchell. The hydraulics of this building are where we differ [from a smaller building] because of the extreme height of the building; what SOM has rightly done is taken established practices but extended them a bit - we've had to push the boundaries.

They've taken established principals and refined them for the ultra high-rise sector," he adds. This has resulted in the use of higher specification materials and products such as pumps than may normally be used in a commercial high-rise structure. It has also meant the need for detailed stress analysis at the pipework expansion and contraction points because of the extreme nature and size of the MEP services being installed. We're operating at higher pressures than you would normally see in the construction industry generally," explains Mitchell.

It's quite easy to specify - you specify by the design pressure - but when it comes to actually selecting the equipment there's a lot of responsibility involved in making sure that we get the right products for the application," he stresses. All equipment used in the MEP systems has also passed anti-seismic and anti-vibration specifications that take into account the natural movement and deflection of the building. The building is split into five zones, with the main mechanical and electrical plantrooms located at approximately 30-floor intervals. These typically feed the 15 floors above and 15 floors below.

The primary distribution route for services is through main risers within the central core of the structure, which remains the same size to level 150 despite the overall building shape tapering with height. The smaller floor footprints at the higher levels mean that lower capacities of plant such as pumps, air handling units and heat exchangers are needed. A central building management system (bms) will oversee the MEP system operations throughout the tower. Local control panels will be mounted in each plantroom and the podium, these outstations will communicate with each other and the central bms control rooms over a main fibre optic backbone cabling system.

All MEP systems will be connected to the bms, which is used to control and monitor all the services distributed around the building. The bms will interface with other systems such as fire alarms, security and the hotel management system to provide a fully integrated control and monitoring system for the entire project.

Installation of services

With the tower central to a very tight site within an inner-city location, a major logistics plan was needed to ensure build schedules could be maintained and materials and labour delivered to the correct place when needed. Most deliveries have been made during the night and storage space has been made available to the MEP contractors within the podium and basement areas of the tower so bulk supplies of materials could be ordered.

"Great thought was given regarding the material and labour movement inside the building," assures Greg Sang, director - projects, Emaar. "For example, all materials are shifted to the job place during the night time and each contractor is given specific timings for shifting materials and labour," he adds.

PROJECT: Burj Dubai

• Client: Emaar Properties
• Project manager: Turner Construction International
• Main contractor: Samsung Corporation
• Architect and designer: Skidmore, Owings and Merrill (SOM)
• Supervision consultant: Hyder Consulting Middle East
• MEP consultant: Skidmore, Owings and Merrill (SOM)
• MEP contractor: ETA-Voltas-Hitachi Plant JV
• Lighting designer: FMS
• Lift contractor: Otis
• ELV contractor: Johnson Controls


CONTRACT DETAILS:

• Tender date: April 2005
• Construction start date: August 2005


SUPPLIERS:

• AHUs: Klimak
• BMS: Honeywell
• Boilers: Hurst
• Cable: Ducab
• Cable management: Barton, KSC
• CCTV: Bosch, Johnson Control
• Chilled water pumps: KSB
• Chillers: Trane
• CHW valves: Milwaukee
• Commissioning valves: Tour & Andersson
• Controls: Honeywell
• Control valves: Honeywell
• Drainage: National Plastics, Spears
• Ductwork: Emirates Ducts, Weathermaker
• Electrical accessories: Crabtree
• Electrical distribution: ABB
• Emergency luminaries: CEAG
• Expansion joints: ATS/Yoo Chang
• Extract fans: Greenheck
• Fan coil units: Mekar
• Fire alarm/detection: Honeywell
• Fire dampers: KBE
• Fire pumps: ITT AC
• Fire smoke dampers: KBE
• Flues: Midtherm
• Grilles and diffusers: Air Master, Anemostat
• Heat exchangers: Alfa Laval
• HV switchgear: ABB
• Insulation: Cape East, Kimmco
• Lighting controls: Dynalite
• LV switchgear: ABB
• Plumbing pumps: ITT Lowara, ITT Vogel
• Power busbar: Cutler Hammer, Eaton
• Pressure independent control valves: Tour & Andersson
• Public address system: Crolon, Tanoy
• Pressurisation: Armstrong
• Sanitaryware: Duravit, Hansgrohe, Dornbracht
• Sewage/sump pumps: Grundfos
• Sound attenuation: Prime Tech
• Sprinklers: NAFFCO
• Standby generation: Caterpillar
• VAV boxes: Solid Air
• Water heaters: AO Smith


BURJ DUBAI: THE FIGURES

• 121,000 light fittings;
• 170 pumps;
• 34km chilled water pipework;
• 4,000 fan coil units;
• 140 air handling units;
• 3,600 fans;
• 52 heat exchangers;
• 225,000 chilled water pipe fittings;
• 33,000 chilled water valves;
• 74.15MW electrical load;
• 1.8 million metres of conduit;
• 55km cable tray;
• 1.5 km of busbar;
• 250km lv cables;
• 20km of mv cables;
• 71 transformers;
• 5,000 facade lights;
• 375km fire alarm cabling;
• 10,000TR cooling load.

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