SCHOOL OF ARCHITECTURE, BUILDING & DESIGN Bachelor of Science (Hons) (Architecture) BUILDING SERVICES (ARC 2423)
Project 1: Case Study and Documentation of Building Services Systems The Gardens Mall, Kuala Lumpur
CHAN JASMINE LEE RUN SEN LEONG CARMEN NG TENG WERN TAN KWOK SEONG
0308513 0308226 0314953 0315014 0314700
Tutor: Mr Adib Bin Ramli
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Contents Abstract Acknowledgement 1.0 Introduction 2.0 Fire Protection System 2.1 Literature Review 2.2 Introduction Active: 2.3 Sprinkler System 2.3.1 Sprinkler Head 2.3.2 Sprinkler Tank (Fire Pump Room) 2.3.3 Fire Control Room 2.4 Fire Hydrant System 2.4.1 Fire Hydrant 2.4.2 Fire Hydrant Tank 2.4.3 Fire Pumping System 2.5 Distribution System 2.5.1 Wet Riser System 2.5.2 Hose Reel System 2.6 Fire Alert System 2.6.1 Fire Alarm 2.6.2 Emergency Fire Telephone 2.6.3 Fire Switch 2.6.4 Smoke Detector 2.6.5 Fire Roller Shutter 2.7 Fire Extinguishing System 2.7.1 Portable Fire Extinguisher 2.7.2 Carbon Dioxide Suppression System Passive: 2.8 Passive Fire System 2.8.1 Fire Escape Stairs 2.8.2 Emergency Door 2.8.3 Evacuation Circulation and Assembly Point 2.8.4 Fire Compartmentation
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3.0 Air Conditioning and Mechanical Ventilation 3.1 Literature Review 3.2 Introduction Air Conditioning (Centralised) 3.3 Centralised Chilled Water Air Conditioning System 3.3.1 Cooling Tower Make Up Tank 3.3.2 Cooling Tower 3.3.3 Water Cooled Chiller 3.3.4 Expansion Tank 3.3.5 Chilled Water Pump 3.3.6 Air Handling Unit (AHU) 3.3.7 Fan Coil Unit (FCU) 3.3.8 Ducting System Air Conditioning (Split) 3.4 Split Air Conditioning System 3.4.1 Split Unit System Mechanical Ventilation 3.5 Ventilation System 3.5.1 Axial Fan 3.5.2 Commercial Exhaust Fan 3.5.3 Smoke Spill Fan 3.5.4 Pressurization System 4.0 Electricity Supply 4.1 Literature Review 4.2 Introduction 4.3 Main electricity supply system 4.3.1 TNB High Tension (HT) Room 4.3.2 Transformer 4.3.3 Low Tension Room and Main Switch Board 4.3.4 Circuit Breaker 4.3.5 Riser Room and Side Switch Board 4.3.6 Electrical Room and Distribution Board (DB)
4.4 Back-up electricity supply system 4.4.1 Genenator Set 4.4.2 Diesel Fuel 4.4.3 Lithium Cadmium Battery
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5.0 Mechanical Transportation System 5.1 Literature Review 5.2 Introduction
5.3 Transportation System 5.3.1 Elevator 5.3.2 Escalator 5.3.3 Travelator 6.0 Control System 6.1 Literature Review 6.2 Introduction 6.3 Building Automation System (BAS) 6.4 SCADA System 6.5 Control Room 6.5.1 Fire Protection Control 6.5.2 Air Cond & Mechanical Ventilation Control 6.5.3 Electricity Supply Control 6.5.4 Transportation Control 7.0 Conclusion 8.0 References
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Abstract The purpose of doing this case study on the building services systems installed in a building is to identify and understand relevant information related to electrical supply, mechanical ventilation and air-conditioning, mechanical transportation as well as fire protection systems through experiential learning. In order for us to expose ourselves to the integration of various building services systems in a building, The Gardens Mall was chosen as our site subject. Images and notes were taken down during the explanation of Mr Liaw, head of building services, whom brought us around the services room of the building. We understand how each building services functions including the connections and position of different parts equipment. In assisting the validation of research, literature reviews based on various systems were conducted to enhance the process. Building services are the dynamics in a static structure. They provide facilities for light, comfort, movement, communications and convenience. The impact of services in a modern building can be measured against the amount of space they occupy and the cost of installation. Explainations of the principles and systems as well as space implications and regulations related to different building services are stated in this report.
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Acknowledgement While completing this paper, we have gained lots of support from people around. Hence, we would like to take this opportunity to thank all the lecturers, especially our tutor Mr Adib Bin Ramli, for their kind assistance in conducting and helping us to complete the report. Notes and teachings from the lecturers had smoothen our task and deepen our understanding in buidling services. Besides, Mr Ng, the M&E engineer of Empire Shopping Gallery, helped us reached out to many other malls such as Alamanda Shopping Mall and Empire Shopping Gallery for site visiting approval. Unfortunately, we did not get any of the approval. But we are still very grateful for Mr Ng’s efforts and support. Furthermore, we would also like to thank Mr. Liaw, the Head of Building Services of The Gardens Mall, in giving us the approval to have The Gardens Mall as our site subject and also assigning helpful colleagues to show us around and explaining systems and services of the building. Lastly, a big thank you again to those who are mentioned above for being patient while helping us to understand more about the systems and the building.
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1.0 Introduction
Figure 1: The Gardens Mall Entrance
(source: http://www.igbreit.com)
The Gardens Mall, located in the heart of Mid Valley City Kuala Lumpur, a lifestyle mall catering to the high-end market, is the second retail component of Kuala Lumpur Mid Valley City, The architectural design - reminiscent of Chinese sails in a doubleenvelop design is conceptualised by London-based architect Eric Kuhne. The centre boasts of a five-star hotel, a service apartment Tower and two 30-storey office towers at the North/South end; all linked to the Mid Valley Megamall (approximately 1 million sq ft in retail area) by a central atrium spine. The entire project was designed by CGN Architects. And like that the name of the building suggests, The Gardens Mall is a green building that complies to the requirements of Green Building Index (GBI).
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2.0 Fire Protection System 2.1 Literature Review A basic understanding of fire behaviour is necessary for the design professional to choose the appropriate fire protection system to manage the hazard it will protect against. Fire protection system are engineered systems designed to address a specific type and size of hazard. When hazard changes, by increasing the quantity or type of potential fuel, the storage arrangement, or the method of handling and use, reevaluating the adequacy of the fire protection system that is protecting the area is necessary. As buildings change owners and tenants, it is important for the owners or their agents to ensure that all fire protection systems are adequate for the conditions of occupancy. Firefighters performing familiarization drills in buildings must remain cognizant of the type of hazard, the type of process, and the quantities of products in a property because if any of them change, not only will the preplan and response need to be updated, but the adequacy of the fire protection system will need to be reevaluated. In order to assess the fire hazard, a basic understanding of fire chemistry, physics, and the behavior is necessary. This information has provided the firefighting community with better insight and a thorough understanding of fire behavior that is the basis for every manual fire attack undertaken by firefighting crews. In addition, an understanding of fire behavior is critical for anyone pursuing a career in fire protection engineering or fire investigation. You do not need to be a chemist or a physicist to competent firefighter, a fire officer, or an investigator, but you do have to understand how and why fire occurs. In order to extinguish a fire, you must understand what sustains a fire. Thus, by understanding the nature of fire, active fire protection measures have been introduced into the market for a long time. These active fire protection systems are designed to aid the fire fighting communities with automatic and 24/7 survailance. Active Fire Protection Systems depend on the operation of mechanical devices, which are in the form of suppression, extinguishers, sprinklers, alarm and extract ventilation. Passive Fire Protection Systems on the other hand are always present and do not rely on the operation of any form of mechanical device. It gives an effective alternative protection given if there are any vital mechanical failure, ensuring places that are of remote locations can be well protected. - A. Maurice Jones Jr, 2009
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2.2 Introduction to Fire Protection System In the case of fire safety in a building, especially a public building, one of the most important issues is the technique or system of fire protection in different areas. Passive fire protection is one of the components of fire protection in construction industry which mostly focus on reducing the speed of combustion while providing good circulation for escape routes. On the other hand, active fire protection is based on the applying of different fire suppression systems in the building to rescue residents in fire incidents. For example, extinguisher, sprinkler, water base system, none water base system and etc. Based on Malaysia UBBL 1984 law, different building constructions should always have a combination of both components. ( i.e. active and passive)
Fire protection systems come in a variety of types, some working along each other and some independantly; some actively and some passively. In the list of active fire protection systems that were installed in The Gardens Mall are sprinkler system, fire hydrant system, distribution system, fire alert system and carbon dioxide system. And as for passive fire systems, there are fire escape stairs, fire compartment etc.
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2.3 Sprinkler System Info/Function: A fire sprinkler system is an active fire protection measure, consisting of a water supply system, providing adequate pressure and flowrate to a water distribution piping system, onto which fire sprinklers are connected. Although historically only used in factories and large commercial buildings, systems for home and small building are now available at a cost-effective price. Fire sprinkler systems are extensively used worldwide, with over 40 million sprinkler heads fitted each year. In buildings completely protected by fire sprinkler systems, over 99% of fires were controlled by fire sprinklers alone. Each closed-head sprinkler is held closed by either a heat-sensitive glass bulb or a two-part metal link held together with fusible alloy. The glass bulb or link applies pressure to a pipe cap which acts as a plug which prevents water from flowing until the ambient temperature around the sprinkler reaches the design activation temperature of the individual sprinkler head. In a standard wet-pipe sprinkler system, each sprinkler activates independently when the predetermined heat level is reached. Thus, only sprinklers near the fire will operate, normally just one or two. This maximizes water pressure over the point of fire origin, and minimizes water damage to the building.
Components of System: • Sprinkler Head • Sprinkler Tank (Fire Pump Room) • Fire Control Room
Operation of System:
Diagram 2.3: Sprinkler Operation
Typically, in a case of fire, the sprinkler bulbs will break at approximately 180°C. And when these sprinkler bulbs break, the sprinklers will be automatically activated via the sprinkler tank from the fire pump room. In The Gardens Mall, fire tank is usually maintained at 4.5m of water. With the Sprinkler activated, notifications will immediately be sent to the fire control room for authorized personal to handle. 10
2.3.1 Spinkler Head A fire sprinkler or sprinkler head is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively used worldwide, with over 40 million sprinkler heads fitted each year. In buildings protected by fire sprinklers, over 99% of fires were controlled by fire sprinklers alone.
Figure 2.3.1.1: Sprinkler Head
A glass sprinkler bulb is the most reliable and economic device used to actuate a fire sprinkler head. The frangible bulb is simple to use, comprising a small thermo bulb made of glass containing a chemical liquid that will expand rapidly when exposed to rising temperatures, bursting the glass fire bulb at an accurately pre-determined temperature, thereby activating the sprinkler.
Figure 2.3.1.2: Sprinkler Bulb
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2.3.2 Spinkler Tank (Fire Pump Room) Sprinkler tank comes in various shape and sizes. Based on the needs of a building/ house, the capacity and location of a sprinkler tank can be very different. In a case of a different country, the sprinkler tank must also have heaters or other means of preventing freezing may be required since water in sprinkler tanks tends to be inactive for long periods of time.
Figure 2.3.2: Sprinkler Tank
2.3.3 Fire Control Room A Fire Control Centre (FCC) or a Fire Control Room (FCR) are special areas within a building from where major emergency situations can be controlled and monitored and where supporting equipment is provided to assist in that function. It is to assist in clarifying the planning, construction and content required in fire control centres and rooms. Included are the tactical fire plans, to assist fire fighters identify major fire safety features in a building during a fire emergency.
Figure2.3.3: Fire Control Room 12
Analysis The Gardens Mall has comply to the standards set by the uniform building by-laws. But through our walk-around tour, we notice that sprinklers are absent throughout the hallway. Due to high ceiling in the main hallway, sprinklers are generally not effective thus the hallway relies souly on smoke spill fans to help control in case of fire. But in shops and corridors, the distance of each sprinkler obeys the stated length which is 4.6m. According to UBBL: 1. The distance of one sprinkler to next is 4.6 m maximum for extra light hazard class. 2. Sprinkle valves shall be located in a safe and enclosed position on the exterior wall and shall be readily accessible to the Fire Authority. (It is located in an enclosed room at the basement which is easily accessible by fire brigade) All sprinkle systems shall be electricity connected to the nearest fire station to provide immediate and automatic relay of the alarm when activated. (It is connected to the control room)
Figure 2.3.4: High Ceiling and Spinkler Head in shop ceiling level
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2.4 Fire Hydrant System Info/Function: In a building, fire hydrant system is a safety measure or emergency equipment that comprises a series of components such as fire hydrant, hydrant tank, fire pumping system and distribution system. It is a water supply with a sufficient pressure and flow delivered through pipes throughout a building to strategically located network of valves for fire fighting purpose. There are two main types of external hydrant systems: direct from main intake to the pillars and pressurised by fire pump.
Components of System: • Fire Hydrant • Fire Hydrant Tank • Fire Pumping System
Operation of System:
Diagram 2.4: Fire hydrant operation
When a fire is detected, the sensor will be triggered and informed fire pump room to start pumping water from the fire hydrant tank. The water supply will be pumped to the distribution system and arrives to either the hose reel system or landing valves. Both systems are always standby with water, hence continuous of water supply is available for the emergency.
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2.4.1 Fire Hydrant Fire hydrant, also known as pillar hydrant, it is a vertical steel pipe with an outlet, close to which two fire hoses are located. It is usually located less than 30m from the breeching inlet at the building. Each hydrant distance spaces less than 9m to ensure the coverage of water supply for the building. During a fire, the firefighter will break the hoses to let the water flows through the nozzles of the hose. Pressure will drop and detected by sensor in the system which eventually trigger the fire pump to turn on and start pumping water.
Figure 2.4.1: Fire Hydrant
2.4.2 Fire Hydrant Tank Water supply for the fire hydrant system could be derived from a reliable source of water such as street main or a static water supply such as a tank. The amount of water in a fire hydrant tank is determined by the hazard level of the building under consideration. The quantity of water to be stored is usually given in hours of pumping capacity. The water is usually stored in concrete underground tanks. The fire hydrant tanks are essential to be always full, hence there should be no outlet except the one connected to the fire pump and separated with domestic water tanks.
Figure 2.4.2: Sprinkler and wet riser tanks & Access to the water tank
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2.4.3 Fire Pumping System Fire pumping system are usually comprises of high pressure water pumps designed to increase the fire fighting capacity of a building by boosting the pressure in the hydrant system. The main pump is usually electric supported with a backup pump that is powered by diesel-engine. This is to ensure consistent water supply in case the electricity fails.
A jockey pump is a component connected to the fire sprinkler system that maintains the pressure in a fire protection piping system. It creates an artificially high level to drop the pressure of the operation of a single fire sprinkler and eventually triggers the fire pump.
Figure 2.4.3: Electrical fire pumps & Pressure metres of jockey pumps
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Analysis The fire hydrant system in The Gardens is considered fully equipped and well organized. The system has regular inspection and maintenance by the fire authority which makes the system to be constantly in good condition and operable. It also fulfil the requirements by the Uniform Building By-Laws. According to UBBL: 1. According to UBBL Part VIII 225, every building shall be served by at least one fire hydrant located not more than 91.5m from the nearest point of fire brigade access. Depending on the size and location of the building and the provision of access for fire appliances, additional fire hydrant shall be provided as may be required by the fire authority.
2. According to UBBL Part VIII 247, water storage capacity and water flow rate for fire fighting systems and installations shall be provided in accordance with the scale set out in the tenth schedule to these by-laws. Main water storage tanks within the building, other than for hose reel system, shall be located at ground, first or second basement levels, with fire brigade pumping inlet connections accessible to fire appliances. Besides, storage tanks for automatic sprinkler installations where full capacity is provided without need for replenishment shall be exempted from the restrictions in their location.
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2.5 Distribution System Info/Function: The distribution system serves to distribute the water supply pumped from the fire pump room to the specific hose reel system or landing valves. The water distribution system for fire protection system are usually composed of steel or galvanised pipes that are painted in red. There are basically two types of distribution systems. Dry riser system is a system that is filled with pressurized air instead of water. When the fire fighter opens the hydrant, the pressurized air will first rush out. The sensor will detect pressure drop and signal the water pumps to start pumping water to the hydrant. Whereas wet riser system is constantly filled with water connected to the pumps and storage tanks.
Components of System: • Wet Riser System • Hose Reel System
Operation of System:
Diagram 2.5: Distribution System
The diagram above is showing one type of the distribution system. In wet riser system, the water supply is stored separately from the other water supply system. The wet riser tank will supply water to the fire pump system to pump the water to the landing valves for continuous water flow during an emergency. The landing valves in a wet riser system are always filled with water. Hence when the firefighter opens the valve and attaches the hose reel to the breeching outlets water supply will straight rush out from the pipe.
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2.5.1 Wet Riser System Wet riser is a water supply system that is consistently charged with water from a pumped source that functions to distribute water to multiple levels of a building. It comprises of duty fire pump with standby pump discharging into a 150mm diameter riser pipe with landing valves at each floor. Wet riser is a fixed distribution system which requires no fire service resources and it helps to maintain the compartmentation of a building.
Figure 2.5.1: Riser pipes with pressure metres & Wet riser pumps
2.5.2 Hose Reel System Hydrants inside the building should be furnished with required equipments such as hose pipes and fire extinguisher located in the hose cabinet. This is to ensure the occupants in the building could suppress the fire at the early stage in the very first minute. The landing valves are always standby with water supply as wet riser system is applied to the building fire protection system. The system is manually operated and allows a coverage of 30m away from the hose.
Figure 2.5.2: Hose reel and riser pipe system
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Analysis The Gardens has only one distribution system which is the wet riser system. It was decided based on the size and needs of the building, hence one distribution system is sufficient for the whole shopping mall excluding the residential area above The Gardens. According to UBBL: 1. According to UBBL PArt VIII 231, wet rising systems shall be provided in every building in which the topmost floor is more than 30.5 metres above fire appliance access level. A wet riser shall be provided in every staircase which extends from the ground floor level to the roof. 2. According to UBBL Part VIII 231 (2), a hose connection shall be provided in each fire fighting access lobby.
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2.6 Fire Alert System Info/Function: Fire alert system is used to inform the occupants to evacuate the building in the shortest time. Therefore it is a very important system to any buildings in its fire protection system as it acts as an announcer. A basic fire alert system consists of fire alarm and emergency fire mobile. The fire alarm will rings when it is signaled by the sensor when there is a fire or smoke detected whereas the emergency fire mobile is used to contact the local fire authority so that external help could reach in the shortest time.
Components of System: • • • • •
Fire Alarm Emergency Fire Telephone Fire Switch Smoke Detector Fire Roller Shutter
Operation of System:
Diagram 2.6: Fire Alert Operation
When smoke is detected by a smoke detector, or the temperature rise up until a limit that causes the valves in the sprinkler to break, both of the system will send signals to the control room and triggers the fire alert system. If someone breaks the glass of a fire alarm the fire alert system will be activated too.
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2.6.1 Fire Alarm A detection of fire to alert people through visual and audio appliances when a fire is present. It is usually triggered by the system when a sensor signals the control room to inform detection of fire or smoke. It can be manually triggered too by breaking the glass of fire alarm.
Figure 2.6.1: Fire alarm bell and Fire alarm trigger
2.6.2 Emergency Fire Telephone Emergency fire telephone can be usually found in the system rooms such as fire pump room and electrical room. It is a hard-wired emergency telephone system designed to help firefighters and emergency personnel communicate fast and effectively in large and complex sites. Easy to install, highly reliable and extremely simple to use which is benificial to the public.
Figure 2.6.2: Emergency Fire Telephone from public to fire control room
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2.6.3 Fire Switch The fire switch is a specialized switch disconnector/isolator. These switches can often be seen on the outside wall of shops, industries or commercial buildings. They are used by firemen to turn off neon lighting or other electrical equipment in case of fire to prevent the overheated equipment from exploding. To be effective and safe, they should be robust & reliable design in non-flammable material like aluminum and also be a highly visible color, like red.
Figure 2.6.3: Types of fire switches
2.6.4 Smoke Detector A smoke detector is a device that senses smoke, typically as an indicator of fire. Commercial and residential security devices issue a signal to a fire alarm control panel as part of a fire alarm system, while household detectors, known as smoke alarms, generally issue a local audible or visual alarm from the detector itself. Smoke detectors are typically housed in a disk-shaped plastic enclosure about 150 millimetres in diameter and 25 millimetres thick, but the shape can vary by manufacturer or product line.
Figure 2.6.4: Smoke Detectors
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2.6.5 Fire Roller Shutter Automatic closure in event at fire is actuated by fusible link (fuses at 71 °C). Where interfacing with a smoke detector or fire alarm system is required, the fusible link can also incorporate a hold – open magnet. Provision of the interfacing work is by the fire control subcontractor. When the daylight opening exceeds 4000mm in width, an additional fusible link is to be provided, located at the other end and connected via a cable to the fusible link on the operator side.
Figure 2.6.5: Fire Roller Shutters
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Analysis The fire alert system in The Gardens has fulfilled the Uniform Building By-Law. Fire alarms can be found abundantly throughout the whole mall. In each of the server rooms and control rooms, emergency fire mobiles are available for safety purpose. Fire switches are available too so that the firefighter could switch off the electricity to avoid electricity shock. According to UBBL: 1. According to UBBL Part VIII 237, fire alarms shall be provided in accordance with the tenth schedule to these by-laws. All premises and buildings with gross floor area excluding car park and storage areas exceeding 9290 square metres or exceeding 30.5 metres in height shall be provided with a two-stage alarm system with evacuation to be given immediately in the affected section of the premises while an alert be given in adjoining section. Provision shall be made for the general evacuation of the premises by action of a master control. 2. According to UBBL Part VIII 239, there shall be two separated approved continuously electrically supervised voice communications systems, one a fire brigade communications system and the other a public address system. 3. According to UBBL Part VIII 240, every floor or zone of any floor with a net area exceeding 929 square metres shall be provided with an electrical isolation switch located within a staircase enclosure to permit the disconnection of electrical power supply to the relevant floor or zone served. The switch shall be of a type similar to the fireman’s switch specified in the Institution of Electrical Engineers Regulations then in force.
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2.7 Fire Extinguishing System Info/Function:
Class A For normal combustible materials such as wood, paper, fabric.
Class B For flammable liquids such as petrol, oil, diesel.
Class C For fire caused by flammable gasses such as butane and methane.
Class D For flammable metals such as sodium, titanium, magnesium.
Class E For electrical equipments such as appliances, wiring, outlets.
Three common types of fire extinguishers: Water based - Filled with air-pressurized water. Only suitable for Class A. Cannot be used on other classes as it will cause a bigger fire and heavier damage. Dry chemical based - foam or powder and pressurized with nitrogen. Suitable for Class A, B and C. i) BC - Filled with sodium or potassium bicarbonate. Leaves a mildly corrosive residue that requires long time of cleaning. ii) ABC - filled with monoammonium phosphate. Leaves a yellow sticky residues that will damage electrical appliances. Gas based - Filled with non-flammable and pressurized gasses. Suitable for Class B, C and E. Ideal for electrical equipments as it does not cause damage on them.
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Components of System: • Portable Fire Extinguisher • Carbon Dioxide Suppression System
Operation of System:
Diagram 2.7: Fire Extinguisher System
When smoke detector detects a fire, the fire extinguishing system will be triggered. The system is usually automatic activated but it has to be stopped manually. Different types of fire extinguishers are designed for different materials that are on fire. Hence the right type of the fire extinguishers for the specific room is very important.
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2.7.1 Portable Fire Extinguisher
Figure 2.7.1.1: Portable fire extinguishers and monthly inspection logbook
Portable fire extinguisher comes real handy when the fire is still at its early stage. It should be located at easily accessible place and always in sufficient amount. Regular inspection of the fire extinguishers are important to make sure they are still in good operating condition.
Figure 2.7.1.2: Fire Extinguisher manual
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2.7.2 Carbon Dioxide Suppression System A system by using inert gases as the medium of fire suppression. It is automatically activated after a detection of the fire through sensor hence carbon dioxide will be released within minutes and extinguished the fire by reducing the amount of oxygen. There are two principles in applying the gaseous fire suppression system: total flooding and local application. Total Flooding - the fire suppression system is used in an enclosed and concealed room. Local Application - the fire suppression is applied directly at the fire affected area. Gas based fire suppression system is usually used in rooms with electrical appliances such as server room and control room. Unlike water based fire protection system, it does not cause damage on the electrical appliances and destroy the room. This system also save up the time and cost in cleaning up the room after the fire as carbon dioxide is colourless and odourless. However, before the system is activated, alert towards the occupants is important to allow immediate evacuation as the high amount of carbon dioxide could lead to death due to suffocation.
Figure 2.7.2: CO2 fire suppression system found in server room
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Analysis Throughout the visit in The Gardens, each of its rooms are well equipped with fire extinguishing system. For example, they applied the carbon dioxide fire extinguishing system in all their electric rooms which will not cause damage on the electrical appliances. Hence, The Gardens did fulfil the Uniform Building By-Laws in designing its fire extinguishing system. According to UBBL: 1. According to UBBL Part VIII 226, where hazardous processes, storage or occupancy are of such character as to require automatic sprinklers or other automatic extinguish fire in the hazardous materials stored or handled or for the safety of the occupants. 2. According to UBBL Part VIII 227, portable extinguisher shall be provided in accordance with the relevant codes of practice and shall be sited in prominent positions on exit routes to be visible from all directions and similar extinguishers in a building shall be of the same method of operation.
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2.8 Passive Fire System Info/Function: An integral component of structural fire protection through compartmentalisation of the overall building through the use of fire rated walls and floors. Passive fire protection system prevents the fire moving from one compartment to another. It delays the growth of the fire and the time collapse of the building structure.
Components of System: • • • •
Fire Escape Stairs Emergency Door Evacuation Circulation and Assembly Point Fire Compartmentation
Operation of System:
Diagram 2.8: Passive Fire Systems
During an emergency, the occupants in the building will be guided to the emergency route to escape from the building. They will be taking the evacuation circulation path and reach the assembly point. In the emergency route there are fire escape stair and fire resistant door to extend the time for escape and prevent the smoke from entering the safe zone. Besides, fire resistant compartmentation is very important in slowing the spreading of fire and protect the occupant from suffocated by smoke.
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2.8.1 Fire Escape Stairs During a fire, all the lift systems are shut down to prevent the occupants from being trapped. Hence, emergency staircase becomes very important as it is the only mean to escape from the building especially multistoreys building. When the occupants enter the emergency staircase, they should be protected from the fire risk and obstruction free.
Figure 2.8.1.1: Spacious and bright stairways for clear exit
The emergency staircase shall have a free access to ease the rescue team for fire fighting. Besides, it should be separated by two fire doors to prevent the fire and smoke to enter. Hence, ventilation at the emergency staircases is important to allow air flow. It can be circulated through passive design openings or mechanical air circulation. Openings towards the road are required to enable evocation of persons during emergency. In addition, the staircase should be always illuminated and well identified so that the occupants are aware of their orientation or whereabouts in the building.
Figure 2.8.1.2: Location of emergency stairs
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2.8.2 Emergency Door The compartmentations of a building are usually linked by the fire door to allow the flow of traffic. Fire doors served two purposes during the emergency which are acting as a barrier to prevent fire and smoke from entering the emergency staircase and a mean of escape for the occupants in the building to reach outside. A fire door is usually fitted with intumescent seal which will expand when the temperature goes up to close up the gap between the door and its frame. Some fire doors are also fitted with ‘cold smoke’ seal to prevent the ingress of smoke around the door edges. There are two types of fire resisting doors which are half hour fire resisting and one hour fire resisting. It is fitted into the building based on the fire hazards based on the building.
Figure 2.8.2: Doors should always be kept closed
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2.8.3 Evacuation Circulation and Assembly Point Evacuation circulation during the emergency is very important as it manages the time for the occupants to leave the building as soon as possible. Most of the time the circulation will leads the occupants towards the outside of the building where the assembly point is located. Travel distance is calculated from a point to the emergency exit so that the occupants can leave the building within the shortest period. Emergency evacuation plan shall be displayed at conspicuous places at the building. The plan shall describe the layout of the building with complete fire fighting equipments and emergency exits. Besides, the emergency assembly point should be clearly marked outside the building.
Figure 2.8.3.1: Fire escape floor plan found outside elevators
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Figure 2.8.3.2: Panorama of the assembly point outside CIMB bank
The assembly point of The Gardens is the space in front of CIMB bank which acts as a valet parking place. Both The Gardens and Mid Valley Mall share the assembly point as it is the centre point of both malls. Based on the observation, the assembly point seems to be a little small to occupy all the occupants from both malls. Besides, the assembly point has cars passing by most of the time which is dangerous to the occupants who escape from the building.
Figure 2.8.3.3: Assembly point on ground floor plan
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2.8.4 Fire Compartmentation Fire compartmentation is divisions of building which are surrounded with fire resistance construction . It is an effective means of limiting the fire damages by delaying the spread of fire to save lives and protect properties. It has features such as automatic fire resistant doors and fire resistant wall partitions. Fire compartmentation can consists of rooms or group of room. If a fire starts in a compartment room, the sealed nature of the room could compartmentalize the fire and prevent it from spreading to other area.
Figure 2.8.4: Differences of having fire rated walls
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Analysis Based on observation, the fire escape route in The Gardens is not well taken care. Some of the emergency exits are blocked by cardboards and trolleys which makes the escape more difficult. Besides, the assembly point for The Gardens are not sufficient to fit all the occupants due to the limitation of the space. Hence the management of The Gardens should take action on the specific components to make sure the route is clear of obstruction and provide a safer escape plan to the occupants. But all passive fire protection is present and effective. According to UBBL: 1. According to UBBL Part VII 173, all exit doors shall be openable from the inside without the use of a key or any special knowledge or effort. Exit doors shall close automatically when released and all door devices including magnetic door holders, shall release the door upon power failure or actuation of the fire alarm. In Part VII 186, all doors used by the public as exit doors from any part of the place of assembly or leading to the open air, shall open only in the direction of exit. Based on UBBL Part VII 164, all fire doors shall be fitted with automatic door closers of the hydraulically spring operated type in the case of swing doors and of wire rope and weight type in the case of sliding doors. 2. Based on UBBL Part VII 168, every upper floor shall have means of egress via at least two separate staircases. The staircases shall accommodate the highest occupancy load of any one floor discharging into it. According to Part VII 198, all staircase enclosures shall be ventilated at each floor or landing level by either permanent openings or openable windows to the open air having a free area of not less than 1 square metre per floor. In Part VII 201, it stated that all staircase enclosures below ground level shall be provided with suitable means of preventing the ingress of smoke. 3. According to UBBL Part VII 166, except as permitted by by-law 167 not less than two separate exits shall be provided from each storey together with such additional exits as may be necessary. The exists shall be so sited and the exit access shall be so arranged that the exits within the limits of travel distance and are readily accessible at all times. In Part VII 169, no exit route may reduce in width along its path of travel from the storey exit to the final exit. 4. According to UBBL Part VII 162, fire doors of the appropriate FRP shall be provided. Openings in compartment walls and separating walls shall be protected by a fire door having a FRP in accordance with the requirements for that wall specified in the Ninth Schedule to these by-laws. Openings in protecting structures shall be protected by fire doors having FRP of not less than half the requirement for the surrounding wall specified in the Ninth Schedule to these by-laws but in no case less than half hour. Openings in partitions enclosing a protected corridor or lobby shall be protected by fire doors having FRP of half hour. 5. According to UBBL Part VII 188, exits in any place of assembly shall be arranged that the travel distance from any point to reach an exit shall not exceed 45 metres for unsprinklered buildings and 60 metres for sprinklered buildings.
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3.0 Air Conditioning and Mechanical Ventilation 3.1 Literature Review The purpose of ventilation is to provide fresh (or at least outdoor) air for comfort and to ensure healthy indoor air quality by diluting contaminants. Historically people have ventilated buildings to provide source control for both combustion products and objectionable odors (Sherman,2004). Currently, a wide range of ventilation technologies is available to provide ventilation in dwellings including both mechanical systems and sustainable technologies. Most of the existing housing stock in the U.S. uses infiltration combined with window opening to provide ventilation, sometimes resulting in over-ventilation with subsequent energy loss; sometimes resulting in under-ventilation and poor indoor air quality. Base on the work of Sherman and Dickerhoff (1998), Sherman and Matson (2002) have shown that recent resident construction has created tighter, energy-saving building envelopes that create a potential for under-ventilation. Infiltration rates in these new homes average 3 to 4 times less than rates in existing stock. As a result, new homes often need provided ventilation systems to meet current ventilation standards, McWilliams and Sherman (2005) have reviewed such standard and related factors. There are a variety of mechanical whole-house ventilation systems including exhaust, supply and balanced systems. Any of these may be in continuous operation or operate intermittently, they may be single-port or multi-port, or the system may be integrated into an existing HVAC system. Mechanical ventilation strategies provided more uniform ventilation rates than natural ventilation (Hekmat, Feustel and Modera, 1986). Properly to most other ventilation systems provide good control over ventilation rates when compared to most other ventilation systems; however, additional energy is required to operate the system. Holton, J.K., M.J. Kokayko, and T.R. Beggs (1997) compared ventilation systems in new production built homes and found infiltration rates ranging from 0.1 to 0.07 air changes per hour in the summer and 0.35 to 0.15 ACH in the winter. As a result, they recommend modern houses include a mechanical ventilation. Reasearchers have studied various configurations of exhaust, supply, and balanced ventilation systems, with and without whole-house re-circulation by the central heating and cooling air handler fan.
- Marion Russell, 2005
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3.2 Introduction to Air Conditioning and Mechanical Ventilation Air conditioner is a system used to treat the air in term of the temperature, humidity, cleanliness and the distribution of indoor air. It is a mechanism system designed to control and stabilise the quality of air in a space such as a building and other form of transportation. An air conditioning system enable the user to control the temperature of the air depending on their thermal comfort. It provides cool air during the warm weather, and warmer air during the cold weather. It also has the capability to control the humidity level in a space, by eliminating or adding moisture to the surrounding air. Air conditioner system brings in fresh air, filter and cool them before releasing the air into an indoor space. At the same time, it pushes out warm stale air of the room through the openings or an exacting outlet. This thus improves the quality of the indoor air by removing any allergies, pollutants, dust and dirt of the air. A building ventilation system that uses powered fans or blowers to provide fresh air to rooms when the natural forces of air pressure and gravity are not enough to circulate air through a building. Mechanical ventilation is used to control indoor air quality, excess humidity, odours, and contaminants can often be controlled via dilution or replacement with outside air. However, in humid climates specialised ventilation systems can remove excess moisture from the air. In the case of The Gardens Mall, both centralised air conditioning and split air conditioning have been used. Besides that, a variety of ventilation precautions have been taken into account too with the installation of smoke spill fan, axial fan etc.
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3.3 Centralised Chilled Water Air Conditioning System Info/Function: The Gardens Mall utilise centralised chilled water air conditioning system. Centralised chilled water air conditioning system is one the most effective and efficient way to distribute cool air circulation throughout the 11-storeys shopping mall, which requires a large amount of cooling load. This system convert hot air intake into cool air through the air handling unit (AHU) and fan coil unit (FCU). It ensures that sufficient fresh air is provided throughout the building. Besides centralised air conditioning system, split unit system is also used in The Gardens Mall for single rooms, small office spaces or tenants that has difficulties connecting the air-conditioning system to the AHU or FCU ducting system. The Gardens Mall has a total of 150 AHU, 55 FCU and 44 split unit system. In the plant room of a centralised air conditioning systems consist of a large compressor, condenser, thermostatic expansion valve and evaporator. These components has a performance and function similar to a typical refrigeration system, but in a larger scale. These components are a lot bigger in size, thus able to provide a higher capacity of cooling load. Cool air is transferred to all tenants and other common spaces that are required to be air-conditioned through the ducting system. In other word, every rooms are provided with cool air only through the ducting system from the air handling unit (AHU) or fan coil unit (FCU) instead of utilising individual cooling coils or other parts of the refrigeration system. By doing so, it reduces any possible noise pollution made by the other parts of the refrigeration system in a space thus creates a highly effective air conditioning system.
Components of System: • • • • • • •
Cooling Tower Water Cooled Chiller Expansion Tank Chilled Water Pump Air Handling Unit (AHU) Fan Coil Unit (FCU) Ducting System
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Operation of System:
Diagram 3.3.1: Centralised Chilled Water Air-Conditioning System @ The Gardens Mall
Based on diagram 3.3, The Gardens Mall adopt the water cooled chiller unit as the main air-conditioning system. Firstly, water is supplied from the cooling tower makeup tank. The heat in the water is removed and release to the atmosphere in the cooling tower and transfer to the chiller at 30째C. The water that goes through the chiller is then filtered through the compressor to further reduce heat through the absorption refrigeration cycle. At this point, the expansion tank will make up the losses of evaporated water to the chiller. Using the chilled water pump, these chilled water is transferred to the cooling coil in AHU and FCU through the insulated chilled water supply piping. The cooling coil in the AHU or FCU will be blown by a blower thus reduce the temperature of fresh air and returned air from the duct or ceiling return diffuser before supplying them to all tenants through the supply air ducting. This cycle is then repeated continuously. The hot water from the AHU and FCU will return back to the condenser through the return chilled water pipe to cool down the temperature, and recirculates from the cooling tower and chiller again. The warm air will be absorbed and return back to the AHU and FCU through the return air ducting. These warm air will be filtered and combine with 10% of fresh air intake, get cooled down once again through the cooling coil and blower before it is ready to be resupply to the tenants.
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Diagram 3.3.2: Centralised Chilled Water Air-Conditioning System
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3.3.1 Cooling Tower Make-Up Tank The function of cooling tower make-up tank is to store the water requirement by daily usage of the system to supply and replace evaporated water in the cooling tower. The amount of water losses in the cooling tower is about 10% of the capacity of water. This is due to the evaporation of the return warm water through the condenser and cooling tower. Besides, some of the water evaporates when it passes through non-air conditioned area as well.
Figure 3.3.1: Cooling Tower Make-Up Tank (source: http://www.pipeco.com.my/Product%20GRP.html)
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3.3.2 Cooling Tower Cooling tower is a device that extracts heat from the water, and release it to the environment while cooling a stream of water. This stream of water is cooled through evaporation, it is cooled by the atmospheric air and circulates to the compressor and condenser. This explains why the occurrence of water losses.
Cooling Tower
Figure 3.3.2.1: Induced cooling tower @ The Gardens Mall
Figure 3.3.2.2: Cooling Tower
In order to increase the efficiency of cooling effect, 6 cooling towers are installed in The Gardens Mall. As seen in figure 2.3.1.2.1, the cooling towers of The Gardens Mall are induced draft cooling tower. It is mechanically operated with a big fan through a baffle area to circulate air throughout the tower, thus cooling the water. The louvers are specially design to ensure air is able to enter the cooling tower. To increase the effectiveness of cooling the water, a fan is installed at the discharge to induce hot moist air out. The incoming cool water is injected towards the baffle area with a spray distribution header to maximise the contacting time and heat exchange surface area between the water droplets and wind. The drift eliminator is installed to prevent the trapping of water droplets in the leaving air stream. 44
3.3.3 Water-Cooled Chiller Chiller is a mechanism that removes heat from the water through a vapourcompression or absorption refrigeration cycle. The component of a chiller plants includes a compressor, condenser, thermostatic expansion valve and evaporator. These components are assembled in a structural steel framework into a chiller package. The piping required to connect these parts is also enclosed in this unit making a highly compact central air conditioning plant. The chilled water in a chiller is circulated through a heat exchanger to cool the air or equipment. The heat waste produced by the refrigeration will be exhausted to the atmosphere to prevent affecting the chilled air or water, or conserved for heating purposes. The efficiency of a chiller depends on its design, performance, maintenance and product life cycle environmental impact.
Figure 3.3.3.1: Chiller Room
A compressor can be driven by a motor or belt via pulley arrangement connected to the motor. In a compressor, it squeezes the fluid and decreases the gas in size to create a compact fluid molecules and increase the energy and temperature. When the refrigerant leaves the compressor and to the condenser, it will be in a high temperature and pressure state. The condenser will cool down the heated refrigerant gas and condenses it back into a liquid form. This refrigerant is transferred to the expansion valve when it became high in pressure and low in temperature liquid. The expansion valve is used to remove pressure from the liquid refrigerant to allow expansion or change of state from a liquid to a vapour in the evaporator. The high pressure liquid refrigerant that enters the expansion valve is warm, and the liquid refrigerant exits the expansion valve is cold.
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Figure 3.3.3.2: Refrigerants
In The Gardens Mall, there are 5 big chillers which provides 4000 tons of capacity and 4 small chillers with 600 tons capacity. However, in order to conserve energy consumption of the building, only 4 big chillers and 1 small chillers are normally in operation. As seen in figure
Figure 3.3.3.3: Computerized touch panel in chiller plant room
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3.3.4 Expansion Tank Expansion tank is used to replace water lost automatically due to pump gland leakage and other losses. Every closed recirculating system needs an expansion tank to take care of expansion and contraction of water in the chiller due to temperature change as well.
Figure 3.3.4.1 Expansion tank
3.3.5 Chilled Water Pump In the chilled water plant centrifugal pumps are the prime movers that create the differential pressure necessary to circulate water through the chilled water and condenser water distribution system.
Figure 3.3.4.2: Chilled Water Pump
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3.3.6 Air Handling Unit (AHU) There are 150 units of AHU installed in the 11-storeys Gardens Mall. The AHU used in The Gardens Mall are installed with ductwork system to have a better and more organise air flow system. This will assure the air-conditioning quality and increase energy efficiency.
Figure 3.3.6.1: Location of AHU @ The Gardens Mall
An air handling unit (AHU) is a part of the heating, ventilating and air-conditioning (HVAC) system device used to regulate and circulate air. The air handling system consist of a blower, cooling coil, filter racks or chamber, sound attenuators and dampers. These components are compacted in a large metal box. An air handler are usually connected to a ductwork ventilation system that distributes chilled air throughout the whole building. Through the ducting system, it also absorbs warm air from the building back to the AHU to filter and recirculate it into cool air. Besides that, there are also some AHU that discharge and admit air directly to the air-conditioned spaces without the ducting system.
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Figure 3.3.6.2: Schematic diagram of Air Handling Unit
The air handling unit is connected to the chiller plant through chilled water piping to receive chilled water supply. This chilled water passes through the cooling coil, with the blower blowing across this cooling coil to cool the air that is induced into the AHU. This cool air will be passed over the air filter and supply the filtered air to spaces that is required to be air-conditioned through the supply ducting.
Figure 3.3.6.3: AHU, AHU air filter, Motor pump, Cooling coil (clockwise)
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3.3.7 Fan Coil Unit (FCU) The fan coil unit (FCU) serves the same function as the air handling unit (AHU), but only covers a smaller area range of the building. It is normally used at smaller space such as the office or tenants that is unable to connect to the AHU ducting due to the location of the tenants. The fan coil unit is also connected to the same chiller plant as the AHU to receive chilled water supply.
Figure 3.3.7: Fan Coil Unit
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3.3.8 Ducting System The ducting system can be divided into two component, which is the supply air duct and return air duct. It is connected to the AHU and FCU to supply cool air to various rooms and space, and to absorb warm air back to the AHU and FCU system for the warm air to be recirculates. There is one main supply duct that bifurcates into a few smaller ducting that will then supply the air to all the tenants and common spaces to be cooled. The return ducting works the same way as well, with a various small ducting system that connects to the main duct and to the AHU and FCU. These ducting systems are insulated with fibreglass aluminium to maintain the cooling effect before providing the cool air to various space and rock wool reduce noise pollution. The ducts are designed to have an even distributed of cool air to the tenants as per their heat loads.
Figure 3.3.8.1: Supply & return pipe
Figure 3.3.8.2: Air duct outlet
Figure 3.3.8.3: Ducting with aluminium insulation
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On figure 3.3.8.4, is a general example layout of a ducting system. The cool air is distributed through a main ducting supply before it is divided into a few branches at different locations. The hatched area of the ducting shown in the layout, is insulated with both rock wool and fibreglass to reduce sound pollution produced by the AHU, whereas as the part without hatchings are only insulted with fibreglass to ensure the temperature of the supply cool air through the ducting is maintained.
Figure 3.3.8.4: General ducting system layout plan
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Analysis The centralised chilled water air conditioning system in The Gardens Mall, is relevant to the Malaysian Standard Code of Practice on Energy Efficiency and Use of Renewable Energy (MS1525). Based on MS1525, code 8 (2.2) under System and Equipment Sizing, it is stated a minimum of 2 chillers or a single multi-compressor chillers should be provided to meet the required load if the design load where the chillers are used exceeded 1000 kWr (285 tons). Besides that, code 8 (2.3) also stated that, multiple units of the same equipment type, such as multiple chillers, with combined capacities exceeding the design load may be specified to operate concurrently only if controls are provided which sequence or otherwise optimally control the operation of each unit based on the required cooling load. The Gardens Mall has meet this requirement by installing 5 big chillers and 4 small chillers. During normal operation day, only 4 huge chillers and 1 chillers are in usage. The extra chillers are installed as a precaution in case there is any breakdown or maintenance going on, the other one would take turn from it. According to MS1525: 1. Under code 8(5) of MS1525 states that all piping installed to serve the building should be adequately insulated to prevent excessive energy losses. The chilled water piping of The Gardens Mall is well insulated by Polyuthelene (PU) form as a protective layer for the pipe. Besides, it act as an additional insulation with vapour barriers. It absorb the condense water produced by the compressor when cold is produced from compressing the refrigerant gas to cool liquid, thus preventing condensation. 2. According to code 8(6) under piping insulation system, all ducts, plenums and enclosures installed in or on buildings should be adequately insulated to prevent excessive energy losses. The Gardens Mall has also meet the requirement by using fibreglass and rock wool as their ducting insulator. This insulators is able to increase the efficiency of cool air supply as it prevent the heat exchange of the cool air and surrounding warm air though the ducting. Besides, the insulation also help to absorb any noise produced by the AHU or FCU. 3. Based on UBBL, the third schedule (by-law 41), 3(1) state that the filters for the removal of airborne bacteria shall be provided at all discharge points to the requirements of the governing health authority
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3.4 Spilt Unit Air Conditioning System Info/Function: Split units is divided and place in two areas, the hot compartment which is located outside a building, and a cold compartment is placed indoor. As seen in figure 2.3.2.1, in the hot compartment consist of a condenser, compressor and a hot coil, while the cold compartment has an evaporator, expansion valve and a cooling coil.
3.4.1 Split Unit System
Figure 3.4.1.1: Split Unit System @ basement of mall
There are two types of split system available, which is the mini split system and central system. The Gardens Mall utilises central system, which uses ducting to deliver the cool air to various spaces. There are 44 units of split units installed in The Gardens Mall. A plus point for utilising split system is that the air will be cooled outside, before it is transfer back into the indoor unit. Therefore, it prevents the heat generated from staying in the interior and also reduces noise pollution.
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Figure 3.4.1.2: Operation of split unit
In this system, refrigerant is used to cool and dehumidify the air rather than chilled water used in the centralised system. It uses chemical refrigerant to evaporate and condense the air repeatedly in a closed system of coils. This compounds have properties enabling them to change at relatively low temperatures. When hot air passes over the low pressure expansion valve, the refrigerant changes from liquid to gas state. This cold gas will run through the cooling coil to absorb heat thus cooling the air inside the building. In order to keep the efficiency of the cooling effect, this refrigerant can be converted back to gaseous state by transferring it through the hot coil at high pressure. At this stage, the gaseous refrigerant will be heated though the compressor and convert back to liquid state. The warm air produced through this process will be directed out to the atmosphere using a second fan, which is the condenser coil. As the refrigerant gas changes back to liquid form, it will be recirculates to the expansion valve to cool the air in the building, thus the process repeats again.
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Analysis By using the split unit air conditioning system, it provide flexibility for zoning and cooling smaller individual rooms and spaces that is difficult to be connected to the AHU and FCU ductwork. The small size split unit system has also ease the installation of the air-conditioner and also save spaces as it does not require an individual room for the separate mechanism to compress the refrigerant in order to cool the air.
The difference between the split unit and centralised system is that split unit uses only refrigerant to cool the air, while the centralised system uses chilled water to cool the fresh air. The benefit of using a split unit is that the tenant will have a full control over the operating system of the individual air-conditioner. The tenant is able to control the temperature of its air-conditioner units and the switch button thus it is more energy saving. However, the centralise system is a more energy efficient choice for large building like The Gardens Mall as it requires a large cooling load to cool down the whole building. Furthermore, the split unit which utilises refrigerants as the main source of the cooling process contributes to global warming and ozone depletion potential due to the Chlorofluorocarbon (CFC) and Hydrochlorofluorocarbons (HCFC) produced. Similar to the centralised system, the split unit of The Gardens Mall is in-line with the building requirement stated in MS1525. It has fulfil the requirement of having insulations for both the piping and ductwork system. According to MS1525: 1. 8.5 Piping insulation All piping installed to serve buildings and within buildings should be adequately insulated to prevent excessive energy losses. Additional insulation with vapour barriers may be required to prevent condensation under some conditions. 2. 8.6 Duct system insulation All air conditioner ducts, plenums and enclosures installed in or on buildings should be adequately insulated to prevent excessive energy losses. Additional insulation with vapour barriers may be required to prevent condensation under some conditions.
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3.5 Ventilation System Info/Function: Building ventilation system is used when the natural forces of air pressure and gravity are not sufficient to circulate air through the building spaces. The main function of ventilation system is to control indoor air quality, excess humidity, odours, and contaminants can often be expelled through exchange and replacement with outside air. In hot and humid country such as Malaysia, specialized ventilation systems can remove excess moisture from the air as well as bringing fresh air indoor. Besides exchange of clean air, ventilation system also contributes in fire protection system. It is able to absorb smoke during the fire and prevent the spreading of smoke to the entire building. Axial fan, commercial exhaust fan, smoke spill fan and pressurized system are strategically installed throughout the building to ensure the efficiency of smoke expelling whenever fire occurs.
Components of System: • • • •
Axial Fan Commercial Exhaust Fan Smoke Spill Fan Pressurized System
Operation of System:
Diagram 3.5: Operation of Ventilation System
In The Garden’s Mall, the ventilation system is very much standard. Its ensures all restaurants and restrooms are well equiped with the commercial exhaust fan and F&B exhaust fans. And in the case of fire protection, smoke spill fans are installed to ensure air change. Axial fans are also used to aid the smoke spill fan and staircase pressurized system.
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3.5.1 Axial Fan Axial fan (Figure 3.5.1.1) is capable of efficiently delivering very large flow volumes at low pressures with high specific speed. The air flow in axial fans is conducted in parallel to the axis of rotation which is in axial direction to force air into the shaft. It helps to exhaust air and accelerate air flow in areas where it is too low to guarantee a sufficient air change especially in the car park (Figure 3.5.1.2) of The Gardens Mall. It ensures the air in the car park area is constantly in motion in the meanwhile increasing the clean air ratio. Besides, axial fan also allows fast smoke and heat extraction to prevent heat and smoke from spreading into other car park areas. The smoke control ability will facilitates the work of fire fighters and prompts the action of rescue. Axial Fans in The Gardens Mall are equipped with external housing and an electric motor integrated into the fan hub. This allows space saving accommodation of other devices due to its compact construction.
Figure 3.5.1.1: Large axial fans located at low circulation areas like basements
Figure 3.5.1.2: Axial fan found in carpark basement 58
3.5.2 Commercial Exhaust Fan
Figure 3.5.2.1: F&B exhaust fan
Commercial exhaust fans are greatly used in the area that produce higher amount of smoke and odour such as kitchen and washroom (Figure 3.5.2.1) in The Gardens Mall. They remove odours and improve indoor air quality by expelling smoke, grease and unpleasant smell. Besides, commercial exhaust fan also able to remove moistures and reduce level of humidity. High humidity in the kitchen especially will cause mold and bacteria growth which can eventually result in major health problem to the consumers as well as the workers. Washroom’s exhaust fans on the other hand are installed to exhaust stinks and humid air to the outdoor. The exhaust fan works by absorbing the smoke through the hood and transmitted via exhaust duct which eventually expelled by the exhaust fan located at the roof top (Diagram 3.5.2.2). Most of the commercial exhaust fan has its own fire alarm tenant system in purpose of protection during fire incident. However, the system is optional and have to be installed by the tenant in The Gardens Mall.
Diagram 3.5.2.2: Schematic diagram of commercial exhaust fan in kitchen 59
3.5.3 Smoke Spill Fan Smoke spill fan (Figure 3.5.3.1) is used in The Gardens Mall to create smoke free areas beneath a buoyant smoke layer as well as negative pressures in fire affected areas (Diagram 3.5.3.2). It assists in evacuating people from The Gardens Mall, reducing fire and smoke damage, facilitating firefighter and retarding the spread of fire, changing 6 air change to 12 air change. Smoke spill fan is a mechanical ventilation system that exhausted the products of combustion to the outdoor. The system consists of large fans, dampers and vents that open in a fire to allow smoke to exit the building.
Figure 3.5.3.1: Smoke spill fans located near the roof top
Diagram 3.5.3.2: Schematic diagram of the operation of smoke spill fan 60
3.5.4 Pressurization System Pressurization system is installed in The Gardens Mall in order to prevent smoke from migrating into the stairways, lobbies, corridors and fire-fighting shaft during the evacuation of occupants. It is a form of mechanical ventilation which maintains a positive pressure in combustion areas by pressurizing the stairwell with respect to the rest of the building. The pressure differentials are controlled by using dedicated supply fans and dampers in order to supply the stairways with fully outdoor air. A series of pressure switches also being allocated along the shafts to control and ensure correct pressure within the stairs is maintained. The pressurization system in The Gardens Mall consists of three important components which are Supply Air, Pressure Relief, and Air Release. Supply Air is where the air is injected into the area that is to be protected while Pressure Relief is to avoid overpressure when doors are closed and Air Release is where the air and smoke is released from the fire area. These three components could create a positive pressure difference which prevents lobbies and staircases from filling up with smoke.
Diagram 3.5.4.1: Schematic diagram showing the operation of pressurized system
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When there is a fire occur at the second floor, the pressurization system is activated to form a negative pressure by exhausting the corridor of the fire floor (Figure 3.5.4.1). This result in positive pressurization of the rest of the stairways that serve the high-rise portion of The Gardens Mall. This positive pressure is obtained through mechanical fans (Figure 3.5.4.2) that supply outside air into the stairways. The purpose of maintaining the positive pressure differential in the stairways is to keep the stairways clear of smoke and toxic fumes. This is due to smoke can flow only from a higher pressure to a lower pressure. This creates low pressure on the fire while the fans create a slightly higher pressure to control or stop the flow of smoke.
Figure 3.5.4.2: Mechanical air fans that supply outdoor air into stairways
The smoke and toxic fumes are then released through the louvers and openings located on the wall beside the stairway (Figure 3.5.4.3). The excess air will then being expelled to the rooftop through ducting system and exhaust fans.
Figure 3.5.4.3: Louvers located at the sides of the stairways
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Analysis In the case of mechanical ventilation, The Gardens Mall is considered well equiped and very well maintained. Active systems are all up to date with the latest technology has to offer today. And we also realise a common misconception as we explore the many active ventilation. Ceiling fans are commonly seen as ventilation systems as they are usually the most visible mechanical system in a building; however ceiling fans do not provide real ventilation, as there is no introduction of fresh air. Ceiling fans only circulate air within a room for the purpose of reducing the perceived temperature by method of evaporation of perspiration on the skin of the occupants. Also hot air rises therefore; ceiling fans may be used to keep a room warmer in the winter by circulating the warm from the ceiling to the floor.
According to UBBL: 1. Supply air for the system shall be drawn directly from the external, with intake point not less than 5 m from any exhaust discharge openings. 2. For exit staircase serving more than 4 storeys, supply air shall be conveyed via a vertical duct extending throughout the staircase height and discharging from outlets distributed at alternate floor. 3. Buildingsexceeding 25m in height are required by BCA to provide stairwell pressurization to prevent the ingress of smoke into the fire escape stairway.
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4.0 Electricity Supply 4.1 Literature Review The electric power industry shapes and contributes to the welfare, progress, and technological advances of humanity. The growth of electric energy consumption in the world has been phenomenal. In the United States, for example, electric energy sales have grown to well over 400 times in the period between the turn of the century and the early 1970s. This growth rate was 50 times as much as the growth rate in all other energy forms used during the same period. The installed kW capacity per capita in the U.S. is estimated to be close to 3 kW. Edison Electric Illuminating Company of New York inaugurated the Pearl Street Station in 188 1. The station had a capacity of four 250-hp boilers supplying steam to six engine-dynamo sets. Edison’s system used a 110-V dc underground distribution network with copper conductors insulated with a jute wrapping. In 1882, the first water wheel-driven generator was installed in Appleton, Wisconsin. The low voltage ofthe circuits limited the service area of a central station, and consequently, central stations proliferated throughout metropolitan areas. The invention of the transformer, then known as the “inductorium,� made ac systems possible. The first practical ac distribution system in the U.S. was installed by W. Stanley at Great Barrington, Massachusetts, in 1866 for Westinghouse, who acquired the American rights to the transformer from its British inventors Gaulard and Gibbs. Early ac distribution utilized 1000-V overhead lines. The Nikola Tesla invention of the induction motor in 1888 helped replace dc motors and hastened the advance in use of ac systems.
- Mohamed E. El-Hawary, 2008
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4.2 Introduction to Electricity Supply
Figure 4.2: General Electricity Supply Line
An electric power distribution system is the final stage in the delivery of electric power; it carries electricity from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2 kV and 35 kV with the use of transformers. Primary distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage of household appliances and typically feed several customers through secondary distribution lines at this voltage. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level.
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4.3 Main Electricity Supply System Info/Function: Electrical Supply System is the conveyance of electrical power from a power station to consumers’ premises. An electrical supply system included three basic components which are the power station, the transmission lines and the distribution system. The power station is a generator that produce electricity with high voltage current to the consumer. The transmission lines consists of transmission substation and transformer in order to carry the power from power plant to load centres. The voltage is changed by transformer according to different type of consumers. While the distribution system allows electricity to feed the power to the houses and industries through substations. Most of the electricity systems are relying upon three phase AC power as the standard for large scale power transmission and distribution. The transmission through a large scale building undergoes several electrical components. It starts with the substation, which then link down to TNB Tension Room and so on.
Components of System: • • • • • •
TNB High Tension (HT) Room Transformer Low Tension Room and Main Switch Board Circuit Breaker Riser Room and Side Switch Board Electrical Room and Distribution Board (DB)
Operation of System:
Diagram 4.3: General operation diagram of Electricity Supply Line 66
4.3.1 TNB High Tension Room The electrical distribution system starts when the incoming power from two substations located outdoor transfers into the TNB High Tension Room (Figure 4.3.1.1). The main purpose of this room is to allow the high voltage electricity generated from the power plant distributed throughout the Gardens Mall as well as the Mid-Valley located beside it. The High Tension Room provides electricity for up to 11 floors including basement levels (Figure 4.3.1.1).
Figure 4.3.1.1: TNB High Tension Room
Diagram 4.3.1.2: Electric Distribution System @ The Gardens Mall
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It is located at the lower ground of the Gardens Mall with other electrical components (Figure 4.3.1.2). The main reason is to isolate the noise produced by the generator and allow accessibility of maintenance team and electrical engineers from TNB. The room location facing the road is strategic enough for big vehicles such as lorry and van to unload electrical equipment. Besides, its location at lower ground also able to save building construction land instead of having TNB HT room outdoor. The usage of electricity of the entire building is restricted to 10% consumption for electrical efficiency and saving purpose. The BAS (Building Automation System) (Figure 4.3.1.3) is installed to control the supply range of electricity distributed to different tenants and commercial shops. The system also ensure optimum performance of the electricity supply to reduce building energy as well as the maintenance costs due to over high voltage electrical current.
Figure 4.3.1.3: Bas system in HT room, Elevated stairs, Pressurized CO2 Tanks in HT room
As a safety concern, the TNB HT room is elevated 1m to avoid rainwater or flood from entering the room (Figure 4..3.1.3). Staircase was built to allow access of maintenance team to have regular checking to ensure the operation is always in good condition. Besides, pressurized CO2 tanks were installed at the corner of the room as fire protection system (Figure 4.3.1.3). It will release CO2 after the alarm system function in order to discourage the spreading of fire to the entire room.
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4.3.2 Transformer
Figure 4.3.2.1: Transformer
The transformer located at lower ground floor is about 400meter walking distance from the TNB High Tension Room (Figure 4.3.2.1). The main function of the transformer is to step down the electricity from 33KV to 11KV in order to provide electricity for the tenants and landlords. The stepped down current will then carried to Low Tension Room or Main Switch Boards for distribution purpose. The transformer room has several safety precautions such as big circulated exhaust fans (Figure 4.3.2.2) to ensure the room is ventilated and to prevent overheating due to the operation of the machine.
Diagram 4.3.2.2: Ventilation System & Exhaust Fan of Transformer
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There is also a temperature indicator located outside the room and function as alarm system whenever the room exceeding normal temperature (Figure 4.3.2.3).
Figure 4.3.2.3: Temperature Indicator located right outside of transformer room & Alarm System on top of the display
The transformers also protected in a metal cage with ventilation louvers located behind the machine (Figure 4.3.2.4). The louvers allow heat air to expel from the machine in order to reduce the operation temperature. The set back of the metal cage from the wall is to ease the heat release as well as to allow maintenance for mechanical engineers (Figure 4.3.2.4).
Figure 4.3.2.4: Metal cage with louvers & Tarnsformer sets back from the wall
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4.3.3 Low Tension Room and Main Switch Board
Figure 4.3.3.1: Low Tension Room & Main Switch Board
The low tension room and main switch board (Figure 4.3.3.1) receive stepped down current from the transformer to allow electricity to further distributed to riser room and electrical room. According to the Building Service Department, there will be mechanical workers who they called charge man working in schedule to always look after the control of the electricity. The main switch board in the room act as a divisional compartment to supply smaller current to the Side Switch Board and Distribution Boards in order for the usage of tenants and landlords.
Diagram 4.3.3.2: SIEMENS, the manufacturer of most of the electrical switch board
The switchboards was manufactured and installed by an industrial engineering company called SIEMENS (Figure 4.3.3.2), which is a leading technology and service company in Malaysia, mainly provide innovative solutions across the key sectors of the energy, healthcare, industry and infrastructure and cities.
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Figure 4.3.3.3: Busbar located inside the main switch board
To transit current from the low tension room, there is a system called busbar (Figure 4.3.3.3) to further carry the current to different electrical facilities such as Side Switch Board and Distribution Board. The busbar is located inside the Main Switch Board protected by metal housing which has cross sectional area for about 100mm to carry high amount of current. It is made of copper to allow good conductivity as well as high melting point to provide higher resistance to fire.
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4.3.4 Circuit Breaker Circuit Breakers are installed in each panel of Main Switch Board located in Low Tension Room. It functions as an electrical switch that works automatically in order to protect electrical circuit. When there is overload voltage transferred from transformer into Low Tension Room, the circuit breaker will detect the fault condition and interrupt the current flow. The difference between a fuse and a circuit breaker is the fuse only operates once after the damage and must be replaced while a circuit breaker can be reset to normal operation. Besides, circuit breaker also withstand higher voltage current while the fuse only used on lower voltage panel board such as distribution board.
Figure 4.3.4.1: Air Circuit Breaker
There are different types of circuit breaker used in the Gardens Mall. The type of circuit breaker greatly used in Low Tension Room is Air Circuit Breaker (Figure 4.3.4.1). While Vacuum Circuit Breaker (Figure 4.3.4.2) is installed and used on the Side Switch Board.
Figure 4.3.4.2: Vacuum Circuit Breaker 73
4.3.5 Riser Room and Side Switch Board
Figure 4.3.5.1: Interior of Riser Room & Exterior of Riser Room
The Riser Rooms (Figure 4.3.5.1) are strategically located at every level in the Gardens Mall to allow current to pass from Main Switch Board to the electrical facilities. It has electrical distribution equipment such as Side Switch Board (Figure 4.3.5.1) with switchgears and panels that supply electricity mainly to those higher voltage machines for instance lift and elevators. The Riser Rooms also allow vertical cables to carry electricity to the upper floors of the Gardens Mall for instance the plants and machines at the roof top such as chiller plants, cooling towers and lift motor rooms.
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Figure 4.3.5.2: Side Switch Board
The stack up arrangement of the Riser Room from the lowest floor to the highest floor in the shopping mall managed to minimize the length of the electrical cable required. Minimum electrical cable length not only save cost but also reduce the occurrence of voltage drop which may result in higher energy usage.
Figure 4.3.5.3: Location of Electrical Riser Room
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4.3.6 Electrical Room and Distribution Board
Figure 4.3.6.1: Distribution Boards in Electrical Rooms & Warning signs located ar door knob
Electrical Rooms in the Gardens Mall share similar function with the Riser Room which it transfers electricity to the electrical appliances in every storey in the mall. The only difference is Electrical Room carries less amount of voltage compared to the Riser Room. Thus, it supplies only to lower voltage electrical facilities such as lightings, fans and air conditioning units. To control electricity flow and ensure further distribution of current to tenants and landlords, a component of an electricity supply system called Distribution Board (Figure 4.3.6.1) is set up outside Electrical Room. It is mainly used to distribute electrical power to various circuits or consumer points in the Gardens Mall. The panel board included fuses, circuit breakers and ground leakage protection units as safety features to break the current whenever there is sudden high voltage current.
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Figure 4.3.6.2: Single phase Distribution Board & 3 phase Distribution Board
The Gardens Mall is designated as 3 phase and 1 phase power supply depending on the usage of the tenants. Larger consumer units for instance Maybank and Sakae Sushi Restaurant require 3 phase of power supply (Figure 4.3.6.2) while smaller consumer unit such as food stall uses 1 phase of power supply (Figure 4.3.6.3). The greatly use of 3 phase system in the Gardens Mall is due to its economic value which uses less conductor material to transmit electrical power. It also utilised a fourth wire for low voltage distribution which is called neutral wire in order to allow constant voltage in three separate single phase supplies.
Figure 4.3.6.3: Schematic Diagram for 3 phase wires (including neautral wire) 77
Analysis The electrical supply system in The Gardens Mall complies to all the law of UBBL. The safety precautions of the electrical components are taken into consideration to minimize the risk caused by electrical short circuits and malfunction of machines. The TNB Tension Room is elevated to prevent flood entering due to its location at basement. Pressurized CO2 tanks were installed in most of the electrical rooms to encounter fire accident. However, some of the electrical machines seem old and under maintenance and some broken vacuum circuit breaker are left unattended inside Low Tension Room. The situation should be solved by having more regular checking and maintenance by authority personnel. According to UBBL: 1. According to UBBL Section 240, every floor or zone of any floor with a net area exceeding 929 square meters shall be provided with an electrical isolation switch located within a staircase enclosure to permit the disconnection of electrical power supply to the relevant floor or zone served. 2. According to UBBL Section 240, the switch shall be of a type similar to the fireman's switch specified in the Institution of Electrical Engineers Regulations then in force. 3. According to UBBL Section 241, in places where there are deaf persons and in places where by natire of the occupancy audible alarm system is undesirable, visible indicator alarm signals shall be incorporated in addition to the normal alarm system.
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4.4 Back-up Electricity Supply System Info/Function: Modern buildings nowadays are designated to equip with back-up electricity system as emergency power supply during the break down of main power from the substation. This might due to inclement weather, downed lines and malfunctions at a substation. Hence, back up electricity system is essential to sustain the operation of building, which normally based on generators set. Large building normally uses diesel engine driven generators or lithium cadmium battery as emergency supply. These systems are pollution free, thus allowing the placement to be done within the building. In Gardens Mall, an automatic transfer switch is used to connect the back-up electricity system. Whenever there is no electricity supply from the substation, the transfer switch will automatically function and turn the power feed from normal to emergency power. This will triggers the lithium cadmium battery operated started system to start the generators. After the transfer switch is on and the generators start, the building’s power supply will return to its normal state under emergency power supply.
Components of System: • Genset • Diesel Fuel Tank • Lithium Cadmium Battery
Operation of System:
Diagram 4.4.: General operation diagram of Electricity Supply Line
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4.4.1 Generator Set
Figure 4.4.1.1: Generator set for emergency supply & Side elevation of genset
The Gardens Mall has a back-up electricity system that sustain the operation of the whole building when there is a breakdown in power supply. It equips with two power generators (Figure 4.4.1.1) set in order to provide up to two days of electricity before the power supply from TNB recover. The Genset room features ventilation system such as air fin (Figure 4.4.1.2) and exhaust fan system (Figure 4.4.1.2) to allow circulation of air during the machine operation. The main reason is to reduce the heat and risen temperature when the generators are fully under operation.
Figure 4.4.1.2: Air fin & Exhaust fan located on the exterior wall of genset
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As an electrical functional room, it also has CO2 tanks (Figure 4.4.1.3) as an emergency fire system to release compressed carbon dioxide to slow down the spread of fire due to electrical short circuit or malfunction of panel board.
Figure 4.4.1.3: Pressurized CO2 tanks located inside the genset room
Another safety feature at Genset room is the light indicator (Figure 4.4.1.4) located above the door. The green light indicates the admittance of the worker and authorized personnel while the red light resembles the emergency incident such as fire inside the room to prevent people from entering the room until it returns back to green.
Figure 4.4.1.4: Light indicator outside the room of genset
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4.4.2 Diesel Fuel Tank
Figure 4.4.2: Diesel Fuel Tank
The diesel fuel tank (Figure 32&33) is connected to the generator in order to power the operation of the machine after the engine is started. The fuel tank in Gardens Mall is elevated higher than the machine to avoid unnecessary collision and also to perform hydraulic system to supply the diesel efficiently to the generators. The diesel fuel allows combustion of the motor and electric current is generated to further distributed to Low Tension Room and rest of the compartments to be used in the entire building.
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4.4.3 Lithium Cadmium Battery
Figure 4.4.3.1: Lithium Cadmium Battery connected to generator set
The generator set needs a start-up stimulator similar to most of the engine and machinery. In Gardens Mall, lithium cadmium battery (Figure 4.4.3.2) is used to start the machine in order for it to function. It is placed aside of the machine and connected through wire. The battery is essential at this stage in order to allow the operation of the generators.
Figure 4.4.3.2: Schematic diagram of Lithium Cadmium Battery 83
Analysis As for the back-up power supply system, everything seem to be in tip top condition. Machines are well maintained and diesel fuel is always check to ensure a certain amount of fuel must be maintained. Through observation, we suspect that the generator set, diesel fuel tank and lithium cadmium battery are still new and well maintained because the back-up gets turn on only once or twice every year. According to UBBL: 1. According to UBBL Section 240, every floor or zone of any floor with a net area exceeding 929 square meters shall be provided with an electrical isolation switch located within a staircase enclosure to permit the disconnection of electrical power supply to the relevant floor or zone served. 2. According to UBBL Section 240, the switch shall be of a type similar to the fireman's switch specified in the Institution of Electrical Engineers Regulations then in force. 3. According to UBBL Section 241, in places where there are deaf persons and in places where by natire of the occupancy audible alarm system is undesirable, visible indicator alarm signals shall be incorporated in addition to the normal alarm system.
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5.0 Mechanical Transportation System 5.1 Literature Review Of the many decisions that must be made by the designer of a multistory building, probably none is more important than the selection of the vertical transportation equipment—that is, the passenger, service, and freight elevators and the escalators. Not only do these items represent a major building expense, being in the case of a 25-story office building as much as 10% of the construction cost, but the quality of elevator service is also an important factor in a tenant’s choice of space in competing buildings. Although the final decision as to the type of equipment rests with the architect, the factors affecting it are so numerous that the building designer should consult with an elevator expert. This service is available from consultants in the field and from the major elevator and escalator manufacturers. The function of this chapter is to familiarize the architect and engineer with the nature and application of vertical transportation equipment in order to enable them to make preliminary design decisions and interact effectively with consultants. The moving stairway, also referred to as an escalator or an electric stairway, was first operated at the Paris Exposition in 1900. Its modern successors deliver passengers comfortably, rapidly, safely, and continuously at constant speed and usually with no delay at the boarding level. The annoyance of waiting for elevators is eliminated. Also, no time is lost by acceleration, retardation, leveling, and door operation, or by passenger interference in getting in or out of the cars. Instead of formal lobbies and hallways leading to a bank of elevators on each floor and a ride in a small, enclosed box, the electric stairway is always in motion, inviting passengers to ride on an open, airy, observation-type conveyance that can never trap them due to equipment or power failure. In contrast to the generally utilitarian function of an elevator, an escalator also has a decorative/design function, and its open, observation characteristic is frequently used to expose the rider to specific visual panoramas.
- John Reynolds, 2010
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5.2 Introduction to Mechanical Transportation Of the many decisions that have to be made by the designer of a multi-storey building, selection of mechanical transportation is crucial as it relates to users’ comfort when travelling in the building. In The Gardens Mall, there are only vertical transportation systems to aid vertical movement across the mall. The vertical transportation systems available in The Gardens Mall are elevators, escalators, and travelators. Each of these systems have their own pros and cons in transporting people and goods. The quality of vertical transportation service is an important factor in an architect’s choice of space allocation in a building. Therefore, it is important that the architect understands the needs of vertical transportation in The Gardens Mall in order to design the elevators, escalators, travelators. A number of factors affect escalator design, including physical requirements, location, traffic patterns, safety considerations, and aesthetic preferences. Foremost, physical factors like the vertical and horizontal distance to be spanned must be considered. These factors will determine the length and pitch of the escalator. The building infrastructure must be able to support the heavy components. The escalator should be located where it can be easily seen by the general public. In department stores, customers should be able to view the merchandise easily. Furthermore, up and down escalator traffic should be physically separated and should not lead into confined spaces.
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5.3 Mechanical Transportation Components of System:
Diagram 5.3: Components of mechanical transportation in a mall
5.3.1 Elevators Generally, there are two types of elevator, traction elevator and hydraulic elevator. The type of elevator used in The Gardens is gearless traction elevator. This type of elevator can be used in buildings of any height and is very durable. A gearless traction elevator is rarely needed to be replaced if it is well-maintained. The Gardens have chosen this design mainly because of its high speed and levelling of elevator can be controlled more accurately. These elevators usually operate at speeds 500 feet per minute and above. The gearless traction elevator is also more efficient, quieter in operation and more energy saving. Thus, it saves cost and also gives comfort to the users.
Figure 5.3.1.1: Lift Lobby 87
Figure 5.3.1.2: Location of elevators
In one floor, there are 3 elevator lobbies that are accessible by the public. In every group of elevators there is a fire lift. These 3 groups of elevators are placed strategically. The distance between each group of elevators is approximately 30m. There are also fire lifts that are only accessible by staff in The Gardens Mall. These lifts also act as fire lift which can be used by fire brigade during emergencies.
Figure 5.3.1.3: Components of lift shaft and machine room 88
5.3.1.1 Machine Room The elevator machine room in The Gardens Mall is located at the rooftop. The room is located directly above the lift shaft. The machine room consist of the control system, the hoist machine, and the governor. The elevators in The Gardens Mall is provided by MS elevator. The elevator system is also serviced every month by MS elevator.
Figure 5.3.1.4: Control Room, Hoist Machine, Governor (All found in Machine Room)
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Control System
Elevator Control System is responsible for coordinating all aspects of elevator service such as travel, speed, acceleration, retardation, door opening speed and delay, levelling and hall lantern signals. It receives inputs from the elevator car (e.g. button signals) and produces outputs (elevator cars moving, doors opening, etc.).
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Hoist Machine
The Hoist Machine has ropes looped around a sheave. A sheave is similar to a pulley system. It has grooves around its circumference that grips the hoist ropes to control the movement of the elevator car. The sheave is connected to an electric motor. In gearless traction elevators, the motor rotates the sheave directly.
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Governor
The Governor is a safety elevator device which act as a stop device in case the elevator runs beyond the rated speed. Governing ropes also act as a backup in case of the main rope malfunction. The governor rope is looped around the governor sheave and another weighted sheave at the bottom of the shaft. The rope is also connected to the elevator car, so it moves when the car moves. As the car speeds up, so does the governor.
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5.3.1.2 Elevator Car he elevator car carries the passengers and transport them vertically to different levels. The elevator car moves through the lift shaft with the guidance of the guide rail. An elevator car should be made or fire-resistant material. However, the finishes of the car interior is optional. The walls of the elevator at The Gardens are left with steel and the floors are finished with tiles. The maximum load the elevator car can bear is 1360kg. There is a standard car operating panel placed at the sides of the lift door in the elevator car of The Gardens Mall. All the public elevators are disabled-friendly. Thus, there are additional disabled-friendly car operating panels in the elevators. The height of the disabled-friendly car operating panel is 900mm.
Figure 5.3.1.5: Capacity plate and disabled friendly floor buttons
Figure 5.3.1.6: Indications of panel in elevator car
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Hoisting Ropes
Hoisting Ropes connects the hoist machine and the elevator car to carry the weight of the car and its live load. The ropes are attached to the elevator car, and looped around a sheave. The rope is controlled by the sheave, and controls the movement of the elevator car. There are six hoisting ropes in The Gardens Mall elevators. The hoisting ropes are typically made of groups of steel wires specially designed to be able to hold the weight of the car and live loads.
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Travelling Cable
To compensate for the weight of the hoist rope, cables are attached to the bottom of the car and the counterweight. This is to equalise loads regardless the position of the car.
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Elevator Rail
The elevator rails are located at the side walls of the lift shaft. These rails function as the vertical, internal track. These guide rails guide the movement of the elevator car and also the counterweight. These rails act as stabilisation within the shaft and as a safety system in case of emergency stops.
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Counterweight
The counterweight is made up of cut steel plates stacked in a frame attached to the opposite ends of the cables to which the car is fastened. Its movement is guided by a guide rail. Its weight is about the same of the weight of the elevator car when it is 40% full. The counterweight helps provide adequate traction at the sheave to lift the car. With the counterweight, less force is needed from the motor to move the car. When the car weighs more than the counterweight, the motor will provide the difference in force needed to move the car. The counterweight reduces the force generated from the motor. This subsequently reduces power demand and energy cost. At the same time, it also reduces the amount of braking the elevator needs to use, making it easier to control the elevator car. Despite all the advantages, a counterweight also comes with a cost of having to strengthen the overhead machine room floor. The floor should be able to carry the additional structural load of the counterweight.
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Car Buffer and Counterweight Buffer
A buffer is a device designed to stop a descending car or counterweight beyond its normal limit of travel. This is done by storing or absorbing and then dissipating the kinetic energy of the car or counterweight. The elevator system in The Gardens Mall uses an oil buffer and it is located at the elevator pit. The oil buffer requires routine cleaning and painting to assure they maintain their performance.
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5.3.1.3 Lift Lobby There are 3 lift lobbies every floor of The Gardens Mall. 2 of the lift lobbies have 4 elevators and the other lift lobby has 3 elevators. The lift lobbies are quite spacious for traffic flow in two direction and for users to wait. At the lift lobby, there are hall lanterns to indicate the direction of the arriving elevator. There are also hall stations with up and down buttons for users to send signal for the elevator to arrive. There is a smoke detector and sprinkler system at every lift lobbies.
Figure 5.3.1.7: One of the three lift lobbies
Hall lanterns Hoistway doors Fire Escape Plan Hall stations
Figure 5.3.1.8: Indications of an elevator
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5.3.1.4 Bomba Lifts/ Service Lifts In The Gardens, there are fire lifts at every group of lifts. There are also fire lifts that are not accessible by the public. These elevators are for the fire brigade during emergencies. They are also used as service lifts. The travel distance to the fire lifts from the furthermost point is approximately 30m. In case of emergency, all elevators will return nonstop to the ground floor, where they park with the doors open. During power failure or fire emergencies, only the fire lift is operable in manual mode with the use of the firefighter’s key in the car panel. All calls from cars and halls will be cancelled during emergency to prevent people from using the elevator. Call-registered lights and directional arrows will also be deactivated. The fire emergency light or message panel in each car will be activated to inform passengers of the emergency and that the cars will return to the ground floor. The elevator cars can still be used by trained personnel to transport firefighters and for evacuation.
Figure 5.3.1.9: Service lift/ Bomba lift found in the back alley
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5.3.2 Escalator Generally, there are two types of elevator, traction elevator and hydraulic elevator. The type of elevator used in The Gardens is gearless traction elevator. This type of elevator can be used in buildings of any height and is very durable. A gearless traction elevator is rarely needed to be replaced if it is well-maintained. The Gardens have chosen this design mainly because of its high speed and levelling of elevator can be controlled more accurately. These elevators usually operate at speeds 500 feet per minute and above. The gearless traction elevator is also more efficient, quieter in operation and more energy saving. Thus, it saves cost and also gives comfort to the users.
Figure 5.3.2.1: Locations of escalators
In each floors there are 6 pairs of escalators. Two pairs are located along the main atrium and another two pairs on each side of the mall. There are also escalators in the departmental stores, Isetan and Robinsons. These escalators are strategically located to ease vertical movement of the visitors.
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5.3.2.1 Arrangement The escalator arrangement in The Gardens Mall is stacked parallel arrangement. This arrangement may be considered inconvenient due to the need for passengers to walk around the escalator to continue the trip. However, this may be the intention of the architect to force circulation around the shops so that the users will actually walk pass the shops. This parallel arrangement may also have been used for aesthetic purpose as this arrangement is neater.
Figure 5.3.2.2: Arrangement of escalators (Stacked parallel)
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5.3.2.2 Components
Figure 5.3.2.3: Basic components of a escalator
The truss is a welded steel frame that supports the entire escalator and its system. The drive machine (Electric motor) is located at the top of the escalator under the landing floor plate. This drive machine powers the step chain which is located beneath the cladding and the truss. The step chain is guided by tracks in the system. These tracks run from the top of the escalator to the bottom with a bend that turns back to the top. The tracks allow the step chain to move in a loop continuously in a constant speed. The steps disappear at the top and bottom of the elevator, where the comb plates are located. The control cabinet is located at the top of the escalator near the drive machine. The drive machine has malfunction indicators and drive controls. The escalators in The Gardens Mall also consist of a microprocessor malfunction analyser and communication means to transmit the escalator operating conditions to the control room. The handrails are driven by the handrail drive powered from the drive machine. The handrails are means of supporting the passengers when the escalator is moving. The handrails disappear at the handrail guide box and is covered by the skirt panel. The balustrade assembly is designed for maximum safety of persons stepping on and off the escalator. The balustrades are made of tempered glass for transparency. This allows a better view of the surrounding which is important to shops to attract customers. 96
5.3.2.3 Safety Features Among the safety features of an escalator is that the handrails and steps have to travel at the exact same speed. This is to ensure steadiness and balance of the users and to aid stepping on and off the combplates. The steps are large and steady to ensure that the users can stand on the steps steadily. The steps are also designed to prevent slipping. The steps level with the combplates at each landings to prevent tripping. This is accomplished by having three horizontal stops at both ends of the escalator. The balustrade is designed to prevent catching of passengers’ clothing and packaging. A continuous “brush� is located at the skirt panels to prevent catching of any object between the skirt guard and steps. If there are any malfunction with the components or system of the elevator, an automatic service brake will bring the stairway to a smooth stop. Any catching of foreign object in the handrail guide box or the sides of the steps will also cause the escalator to brake. At the ends of the escalators are emergency stop buttons to be operated manually if there is any emergency. An additional safety feature installed in the escalators at The Gardens Mall is the impact sensor. These impact sensors are located at the skirt panels. If there is an impact on the skirt panels, the sensors will send signals to the automatic service brake to bring the escalator to stop.
Figure 5.3.2.4: Safety caution signs
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5.3.3 Travelator A travelator is similar to an escalator. The difference between a travelator and an escalator is that travelators are moving ramps instead of steps. The travelator in The Gardens Mall is also used to transport people from one floor to another floor. Like escalators, travelators do not require waiting. It is constantly moving at a constant speed. Unlike escalators, travelators are disabled-friendly. Travelators can also be used to transport large, bulky things more easily compared to an escalator.
Figure 5.3.3.1: Travelator leading to basement carpark
There are only 2 pairs of travelators in The Gardens Mall. These travelators connect the lower ground floor to the basements. The reason travelators are used at these locations instead of escalators is because of the supermarket at the lower ground floor. Travelators allow people from the supermarket to push their carts to their cars at the basement parking.
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5.3.3.1 Arrangement The travelators are arranged in a crisscross manner. The travelators are designed in such a way that the users can continue their journey to the next level with just a turn to the next travelator. There is no need for users to walk around the travelators to continue their trip. This design makes the travelator friendlier for users that are travelling with carts.
5.3.3.2 Components The components of a travelator is similar to an elevator. The difference is that on the travelator, there is a pallet tread which is powered by the drive machine. The pallet tread moves at about 110fpm. It is almost the same speed as a moving escalator. However, due to the long distance of a travelator, time taken to move from one floor to another floor takes a longer time compared to an escalator.
Landing floor plate Handrail Outer deck cover Pallet tread
Combplate
Figure 5.3.3.2: Components of a travelator
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Analysis The elevators in The Gardens Mall have met all the requirements stated in the UBBL. According to the Building Services Manager, all the elevators are inspected by the Department of Occupational Safety and Health (JKKP) every 15 months. This urges the maintenance crew to service the elevators at least once a month. This is very important to ensure the safety of the users in The Gardens Mall. All the elevators at The Gardens Mall are strategically located near exits at the ground floor. During fire emergencies, all elevators will stop at ground floor and passengers can exit the building conveniently to the gathering location. There will be a fire drill every six months to ensure the elevators go according to the requirement in the UBBL, clause 154. As there are fire lifts at every group of elevators, the requirement in UBBL, clause 243 is fulfilled. There are seven fire lifts in total and they are all located not very far apart from each other. The furthest distance from a fire lift is approximately 20m. All fire lifts also fulfilled the requirement of having smoke detectors at the lift lobbies. The escalators and travelators are relatively safe as they have all the standard safety features with an additional impact sensor at the skirting. The imposed circulation around the escalators is a clever method to attract customers to the shops. The travelators located at the lower ground floor is very appropriate for customers of the supermarket with carts. It is crucial that the architect to consider the necessities and comfort of users when designing and locating all the vertical transportation systems. According to UBBL: 1. Clause 124: For all non-residential buildings exceeding 4 storeys above or below the main access level at least one lift shall be provided. 2. Clause 153: All lift lobbies shall be provided with smoke detectors. 3. Clause 154: On failure of mains power all lifts shall return in sequence directly to the designated floor, commencing with the fire lifts, without answering any car or landing calls and park with doors open. 4. Clause 243: In a building where the top occupied floor is over 18.5 metres above the fire appliance access level fire lifts shall be provided. Fire lifts shall be provided at the rate of one lift in every group of lifts which discharge into the same protected enclosure or smoke lobby containing the rising main, provided that the fire lifts are located not more than 61 metre travel distance from the furthermost point of the floor.
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6.0 Control System 6.1 Literature Review The level of automation in residential and commercial buildings has risen steadily over the years. This is not due to the increasing demand of more comfort and convenience, but also the benefits building automation brings with regard to saving and managing energy. Security is another important factor particularly in residential buildings. Whereas in commercial buildings flexibility is high on the agenda offices buildings, for example, should be designed in such way that they can be easily adapted to meet any change in use or requirements. Commercial buildings within the context of building automation are buildings that serve a purely functional purpose, for example, offices, shopping centres, hospitals, railways stations, airport terminals and underground carparks. In modern buildings there are variety of automation systems for heating, ventilation and air conditioning. To ensure these systems run smoothly and economically, they are fitted with sophisticated controllers, which are often interconnected with each other and to a control centre via field buses and networks. These control systems optimize energy consumption and enable support and maintenance personnel to carry out their jobs more efficiently. Systems in commercial buildings must be flexible. If a company wants to restructure the layout of an office by converting a large conference room into a number of small offices, the layout and set up of the building’s operational equipment must enable these changes. Building automation systems enable you to connect a light switch to a light by simply simply reprogramming the intelligent components, rather than rewiring the electrics. The focus is on flexibility.
- Hermann Merz, 2009
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6.2 Introduction to Control System A signal initiation that is non-manual is considered as automatic. An automatic signal usually comes from a timing device, a sensor such as a daylight or occupancy sensor, or a programmable device such as a microprocessor or computer. This is called an automated system. The system can be elementary, in which an automated signal controls a single action. It can also be very complex, yet treat only a single function. For example, an automated lighting system with sensors activating or overriding presets that activate dimmers and switches. These systems are referred to as a stand-alone automated system. When several stand-alone systems are interconnected and supervised by a controller, it is referred to as an integrated control system. When this integrated system is applied to the individual systems in a building, it is referred to as a Building Automation System (BAS). The Gardens Mall is using this system to control the mechanical, security, fire and flood safety, lighting, HVAC and humidity control and ventilation systems. Another system used in The Gardens Mall is the Supervisory Control and Data Acquisition (SCADA). This system is a remote control system. Remote control is a technique by which an action that can be performed manually at the device being controlled is performed from a remote location. SCADA is used in The Gardens Mall to monitor and control a plant or equipment in the mall.
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6.3 Building Automation System (BAS) Building automation system (BAS) is a term used to refer to a wide range of computerised building control systems. This system is considered as one of the major intelligent building systems. A BAS consists of several subsystems which are connected in various ways to form a complete system. The system has to be designed and engineered specifically around a building to serve the services systems for which it is intended. Although the component parts used may be identical for different buildings, no two systems are the same. Building services include HVAC systems, electrical systems, lighting systems, fire systems and security systems and lift systems. In The Gardens Mall, BAS is used to monitor, control and manage all these services.
Figure 6.3: BAS being operated in The Gardens Mall
Advantages of BAS: By using BAS, reliability of plant and services is increased. BAS monitors the systems continuously and provides preventative maintenance to guarantee the operation of the systems. BAS also helps reduce operating cost of energy required for heating, air-conditioning and illuminating the space. This can be done through programmed start/stop, duty cycling, set-point reset, and chiller optimisations. The contribution of BAS also reduces manpower requirement for maintenance which have a major effect on the annual cost of running a building. BAS provides the most cost-effective means for staff to monitor and maintain a building. With BAS, staff are able to attend to an issue or problem efficiently. This increases the efficiency of the building management.
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6.4 SCADA System SCADA operates with coded signals over communication channels. The major function of SCADA is for acquiring data from remote devices such as valves, pumps, transmitters etc. and then it provides an overall control remotely from a SCADA Host software platform. SCADA Host platforms also provide functions for graphical displays, alarming, trending and historical storage of data. The SCADA system is used in The Gardens Mall for efficiency and safety.
Figure 6.4: Schematic diagram of the operation of SCADA
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6.5 Control Room
Figure 6.5: Control Room
The control room of The Gardens Mall is located at the ground floor and is not accessible by the public. The control room is “hidden� for safety purposes. The control room is the central point of supervision, control, and data collection. There are personnel in the control room to survey and control the entire building’s functioning. From this control room, air-conditioning, heating, ventilating, electrical, fire protection, mechanical transportation, and other systems can be controlled with accuracy and convenience. Data from each systems can be collected at the control room instantly so that operational decisions can be made and automated.
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6.5.1 Fire Protection Control
Main Control Panel Firemen Intercom Master Panel
Figure 6.5.1.1: Control Room
In the control room, the main control panel and firemen intercom master panel are under fire protection system. The main control panel consist of mimic floor plans with indicators to monitor the shopping mall in case of any fire emergencies. When the smoke detector detects a fire or the break glass is broken, indicator of the area where fire is detected will light up, alerting personnel in the control room.
Figure 6.5.1.2: Control Room
During fire emergencies, firemen need a reliable communication facilities to talk to the fire chief that is commanding the fire-fighting and rescue operation. The firemen intercom master panel is for the fire chief to communicate with other firemen. This intercom master panel is linked to intercom consoles located around the building via a fire resistant telecommunication cable. There are “CALL” and “FAULT” indicators on the panel. When a firemen contacts the intercom master panel, the CALL indicator of the location will light up. When the telecommunication cable of an intercom console at a location is broken, the FAULT indicator will light up. With this feature, immediate action can be taken to fix a faulty intercom console. 106
6.5.2 Air Conditioning & Mechanical Ventilation Control
Figure 6.5.2: BAS on air conditiong and ventilation control
The personnel in the control room uses a workstation with BAS to monitor the status of the Chiller Plant, Air Handling Unit (AHU) and the Fan Coil Unit (FCU). Example of information that are shown in BAS are the supply temperature, return temperature, valve control and valve feedback. There are also indicators in the control room for the air conditioning make up pump and the cold water storage tank. These indicators will light up when there are any faults in them.
6.5.3 Electricity Supply Control
Figure 6.5.3: BAS on electricity control
For electrical system, personnel will also monitor through BAS in a workstation. Among components to be monitored in the control room are the high tension room, transformer, low tension room and main switch board, and electrical room and distribution board. Generally, the BAS monitors the power supply to the building.
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6.5.4 Transportation Control
Figure 6.5.4.1: Transportation Control
All elevators in The Gardens Mall are under CCTV supervision in the control room. There is also a lift supervisory panel in the control room to know the status and location of the elevator. During emergencies, the personnel in the control room can be contacted via the intercom in the elevator. There is a mimic diagram for escalators and travelators in the control room that shows the status of the escalators and travelators. There are indications on the diagram to show whether it is running on normal power or emergency power operation. This is for the personnel in The Gardens Mall to keep track of the escalators and travelators.
Figure 6.5.4.2: Plans with location of all transportation systems
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7.0 Conclusion Overall, all four service systems used in The Gardens Mall are rather standard, complying to all the standards set by Uniform Building By Law (UBBL). Covering all four criterias of the building services, we have seen little patterns of The Gardens Mall providing more than the necessary. Placements and circulation are well thought out and strategic passive fire protection is found in every corner. From the strategic concealment of the equipment on the roof to the proximity of the interdependent services to one another, all leading to higher efficiecy. In short, The Gardens Mall was an interesting building to work with and has helped us deepen our understanding in the aspects of building services, The Gardens Mall is a good example of how services and design can come together to form a cohesive whole.
Figure 7.: The Gardens Mall (source: http://en.itravelkaki.com/malaysiamall)
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8.0 References Books:
A. Maurice Jones, 2009, Fire Protection Systems, 1st Edition, Clifton Park : Delmar Cengage Learning Chudley, Roy. 1988. Building Finishes, Fittings and Domestic Services. 2nd Edition. Longman.
Greeno, R. 2000. Building Services Equipment. 5th Edition. Longman. Hall, Frederick E. 1997. Building Services and Equipment. Volume 2. 2nd Edition. Hall, Frederick E. 1999. Building Services, Technology and Design. 3rd Edition. Longman.
Hermann Merz, 2009, Building Automation: Communication systems with EIB/KNX, LON and BACnet. Springer Science & Business Media.
Mohamed E. El-Hawary, 2008, Introduction to Electrical Power Systems, John Wiley & Sons. Stein, Benjamin & Reynolds, John S. 2000. Mechanical and Electrical Equipment for Buildings. New York, John Wiley. Faye C. Mcquiston, J. D. (2005). Heating, Ventilating, and Air Conditioning Analysis and Design. John Wiley & Sons, Inc
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Internet: Anshuman, J. (2013). Basic Elevator Components - Part Two ~ Electrical Knowhow. (n.d.). Retrieved from http://www.electrical-knowhow.com/2012/04/basic-elevatorcomponents-parttwo.html/ Elevators - Escalators & Moving Walkways - Maintenance Programs - Otis Elevator Company - Malaysia. (n.d.). Retrieved from http://www.otis.com/site/my/pages/AboutElevators.aspx?menuID=2/ Fixed Extinguishing Systems, United States Department of Labor, (n.d) Retrieved September 2014 from https://www.osha.gov/SLTC/etools/evacuation/fixed.html/ Grundfos. (2013). Grundfos Literature. Grundfos CR. HowStuffWorks "How Elevators Work". Retrieved from http://science.howstuffworks.com/transport/enginesequipment/elevator5.htm/ Julian, K. Cooling Towers. (2013, March 1). Retrieved October 9, 2014, from http://www.enggcyclopedia.com/2012/02/cooling-towers/
Khemani, H. (2009, September 9). Air Handling Units or Fan Coil Units. Retrieved October 9, 2014, from http://www.brighthubengineering.com/hvac/50539-air-handlingunits-or-fan-coil-units/ Mat B, (2013), Mechanical/Forced Ventilation, Studio B, retrieved October 2014 from http://uol-ventilation.weebly.com/mechanical.html/ "Protective Order." West's Encyclopedia of American Law. 2005. Retrieved October 11, 2014 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G23437703566.html
Robert T, (2011), Fire Hydrant and Inspection, acrp Corp, retrieved September 2014 from https://www.acrp.com/downloads/dso4.pdf/ Russell, M. (2005, August 1). Review of Residential Ventilation Technologies. Retrieved October 10, 2014, from http://www.buildingscience.com/documents/guidesand-manuals/gm-review-residential-ventilation-technologies UNIVERSITY POLICE (n.d.). Fire Extinguishers | POLICE. Retrieved June 22, 2014, from http://www.ulm.edu/police/fire-extinguishers Industrial/ WILD, J.A. , ENG, C.,Mech, F.I. (1998). Smoke Control By Pressurization. England: Fl채kt. Woods Limted England. York (n.d.) Retrieved June 22, 2014, from http://www.johnsoncontrols.com/content/us/en/products/building_efficiency/
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