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BUILDING SERVICES 2
QSB 2714
BACHELOR OF QUANTITY SURVEYING (HONOURS)
SEMESTER 3
TESCO EXTRA (MUTIARA DAMANSARA)
Abang Azrin Bin Abang Affandi
0319073
Chua Jia Cheng
0315160
Goh Jeng Jhieh
0315080
Jake Sia Chyi Sern
0314396
Kellyann Hiew Yau Mei
0319532
Muhammad Aiman Bin Zainul Abidin
0321832
Rachel Emma Betty Ernesta 0317966
1
ABSTRACT
The case study of this report is on Tesco Extra which is located in Mutiara Damansara. The
four building services (mechanical and air-conditioning system, fire protection system,
vertical transportation and electrical supply) is analysed and information on the systems are
given. Recommendation is provided for the fire protection and vertical transportation to
improve the services.
2
ABBREVIATIONS
% Percent
AC Alternating Current
AHU Air Handling Unit
CO₂ Carbon Dioxide
COPHK Hong Kong's Code of Practice for minimum Fire Service Installations and Equipment and Inspection, Testing and Maintenance of Installations and Equipment
dB(a) A-weighted Decibel
DC Direct Current
IT Information Technology
kVAR Kilovolt Amperes Reactive
m/s Metre per Second
TNB Tenaga Nasional Berhad
W Watts
3
LIST OF FIGURES
Figure 1: Air-conditioning (Refrigeration Cycle) .................................................................... 9
Figure 2: Cooling Tower ......................................................................................................10
Figure 3: Centralised System ..............................................................................................12
Figure 4: Multi Zone Variable Air Volume ............................................................................15
Figure 5: CO₂ Fire Extinguisher ...........................................................................................17
Figure 6: Escalator ..............................................................................................................20
Figure 7: Main Components of an Escalator ........................................................................21
Figure 8: One-Way Traffic Escalator ...................................................................................22
Figure 9: Two-Way Traffic (Parallel) ....................................................................................23
Figure 10: Two-Way Traffic (Crisscross) .............................................................................23
Figure 11: Electric Elevator ..................................................................................................27
Figure 12: Hydraulic System ................................................................................................28
Figure 13: Electrical Distribution Grid ..................................................................................29
Figure 14: Transformer ........................................................................................................30
Figure 15: Step-Up Transformer ..........................................................................................30
Figure 16: Step-Down Transformer .....................................................................................30
Figure 17: Service Entrance ................................................................................................31
Figure 18: Example of Distribution Panel.............................................................................33
LIST OF TABLES
Table 1: Differentiation of Systems ......................................................................................11
Table 2: General specification for car speed of a lift ............................................................27
4
LIST OF PHOTOGRAPHS
Photograph 1: Supply and Extract grilles .............................................................................12
Photograph 2: Ducting in Tesco Extra .................................................................................13
Photograph 3: Rectangular Diffuser ....................................................................................13
Photograph 4: Square and Rectangular Diffuser .................................................................13
Photograph 5 : Plan view of 1st floor in Tesco Extra ............................................................16
Photograph 6: Dry Powder Fire Extinguisher .......................................................................17
Photograph 7: Hose reel and fire extinguisher located inside the cabinet with a break glass
and fire alarm above ............................................................................................................18
Photograph 8: Sign boards high above on the wall to easily locate the cabinet ..................18
Photograph 9: Fire Escape with “KELUAR” sign .................................................................19
Photograph 10:Smoke detectors and sprinklers which is noticeable by the red paint .........19
Photograph 11: Handrails of a Travelator ............................................................................22
Photograph 12: Floor Plan of Tesco Extra ...........................................................................24
Photograph 13: Travellator at Tesco Extra ..........................................................................24
Photograph 14: Escalator at Tesco Extra ............................................................................25
Photograph 15: Elevator in Tesco Extra ..............................................................................26
Photograph 16: Service Elevator .........................................................................................26
Photograph 17: Main Switchboard 1 ....................................................................................32
Photograph 18: Main Switchboard 2 ....................................................................................32
Photograph 19: Main Switchboard Room ............................................................................32
Photograph 20: Distribution Panel in Tesco .........................................................................33
Photograph 21: Food Court .................................................................................................34
Photograph 22: Bakery ........................................................................................................34
5
TABLE OF CONTENT
INTRODUCTION .................................................................................................................. 6
PART 1 – PURPOSE OF THE BUILDING ............................................................................ 7
PART 2 – TYPES OF SYSTEM ............................................................................................ 8
Mechanical and Air-conditioning systems ...................................................................................... 8
Fire Protection System ................................................................................................................ 16
Vertical Transportation ................................................................................................................ 20
Electrical Supply .......................................................................................................................... 29
PART 3 – RECOMMENDATION AND SOLUTION .............................................................34
Fire Protection System ................................................................................................................ 34
Vertical Transportation ................................................................................................................ 36
PART 4 – CONCLUSION ....................................................................................................37
6
INTRODUCTION
This report is to observe the building services systems available in our case study. The
building that was chosen is Tesco Extra which is located in Mutiara Damansara. A total of
four systems were analysed; the mechanical and air-conditioning system, fire protection
system, vertical transportation and lastly, the electrical supply. The purpose of the report is
to understand about the systems installed in the building and their functions. Information
about the report is then researched to fully understand the available building services.
7
PART 1 – PURPOSE OF THE BUILDING
Tesco Stores (Malaysia) Sdn Bhd was first founded back in 2001. The company
commenced their operations in the following year in 2002 with the first hypermarket opening
in Puchong, Selangor. They currently have over 50 hypermarkets all across Peninsular
Malaysia. Their stores in Malaysia have a combined floor space of over 4 million square
feet.
The company operates 2 kinds of store formats; Tesco Hypermarkets and Tesco Extra
Hypermarkets. This report is based on the Tesco Extra which is located in Mutiara
Damansara, Selangor, Malaysia. The purpose of Tesco Extra is to provide customers with a
destination to shop for their needs with everything ranging from fresh foods to groceries,
and even including apparels. It carries over more than 60,000 lines of products including
nearly 3,000 of its own brand of products ranging from food to non-food items.
The products and services are focused to serve the needs of small businesses, families
and individuals. Tesco Extra includes a bigger pack sizes, special trolleys and checkouts
along with a committed business development team to support small business owners with
their orders.
8
PART 2 – TYPES OF SYSTEM
Mechanical and Air-conditioning systems
Air-Conditioning System Design Considerations for Tesco Extra
Designing an air conditioning system is a complex process. Every building serves different
purpose. The most important criteria are to design an air conditioning system that is
efficient and cost effective for that particular area to provide comfort to the occupants. In
this case the occupant includes the staff and customers of Tesco Extra. Increasingly,
energy efficiency is a big concern given that it’s vital for reducing running costs and carbon
emissions.
Air Conditioning Design Consideration
1. Heating and/or cooling load
2. Range of suitable units with the required capacity
3. Positioning
4. Sizing the Air Conditioning Systems
Anything that can affect the heating and cooling load has to be considered. This includes
the heat transfer through walls, large windows, roofs, and especially to big hypermarkets,
any system such as mechanical and electrical, comprising of refrigerators for cooling
goods, cold stores which can emit heat into the area.
The system differs in the main shopping area, the server rooms, IT facilities and small
offices. The grilles are visible. The types of system found are common in large commercial
facilities as well as warehouses, and office buildings.
All air conditioning units need a certain amount of space to operate properly and should be
kept clear of dirt and debris.
Ventilation
Ventilation is a process where the air is circulated from the building to ensure there was a
changing of air in any space. Ventilation is important for controlling the temperature and
providing fresh air in closed area. Furthermore, it removes unpleasant smell, moisture and
heat. Ventilation is also used for health purposes to remove noxious dust, air pollution gas
and smoke. Air conditioning system is used to keep the temperature and relative humidity
of the space. The type of air conditioning system relevant to our case study is mechanical
ventilation.
9
Figure 1: Air-conditioning (Refrigeration Cycle)
Compressor
Motorize machine that circulates coolant though a vapour compressor system. Refrigerant
will enter to compressor in vapour state. Compressor will compress the refrigeration to a
high pressure and followed by increasing of the temperature.
Condenser
Change the pressure of refrigeration from hot to cool it and include changing of vapour to
liquid form. Hot gas from compressor will be emitted the heat and condensed the
refrigeration through the coil.
Expansion valve
To make sure there are changing of pressure liquid from high to low pressure. The liquid
automatically become cool because of changing of pressure.
Evaporator
Happen when cold refrigerant is filled and produced by a system of the coil that filled out
cools air around it. The heat liquid refrigeration will be absorbed by coil of evaporator to
produce cool gas. This evaporator will change from liquid to gas form.
10
Centralized System
Centralized system is most commonly used in large hypermarkets. It is actually more
economical if compared to a split unit for large surface areas. In this method a specific
space is provided for AHU/plant room for this system. The space will be used to house a
compressor, condenser, expansion valve and evaporator. Then, the cold air that is
produced by the evaporator will be chilled air and it flow through the ducting system to all
the required rooms. Air duct and diffuser are needed for ducting system.
Figure 2: Cooling Tower
Cooling tower is needed to cool the hot water. Hot water will be delivered to the cooling
tower and the water will be sprayed by sprinklers and then cooled by air in the cooling
tower. From our observation at Tesco Extra in Mutiara Damansara, it was concluded that a
centralized system is being used as a system for their air conditioning in order to achieve
safety, energy efficiency and cost efficiency. The centralization of these systems allow for
better management and system operation. On the other hand, they also require either a
mechanical room adjacent to the controlled space for locating the AHU and large ductwork
in the building space. It is not wise to use split units in the building because it takes high
power and also as it is high maintenance. It will require a large number of split units.
Instead, the centralized system produces high capacity air so that all occupants in the
Tesco Extra can receive the cold air continuously and throughout the daily operations and
services of the market.
11
Table 1: Differentiation of Systems
12
Figure 3: Centralised System
Types of Diffusers
The air is either supplied into or extracted from the
space, and as seen it is wall-mounted. The external
louvers are which through which air is extracted or
discharged from the building.
Photograph 1: Supply and Extract grilles
13
Photograph 2: Ducting in Tesco Extra
The Ductworks branches by a network of round or rectangular tubes made of fiberglass
board particularly in this case. However, other material such as metal sheets, flexible plastic
and wire composite can also be used.
Photograph 3: Rectangular Diffuser
Photograph 4: Square and Rectangular Diffuser
14
Zoning
Zoning is required to divide a space into different zones that have different cooling needs.
With zoning, we can control over the cooling and heating system in order to achieve control
over the temperature. Most places does not get the same amount of sun or shade all day,
therefore the same type of cooling or heating is not the same throughout the day. This
system must include thermostats that is connected through it and controlled by control a
panel. It is an easy-to-use advanced command that provides a seamless interface between
the system and occupancy. The zoning will operate the damper to control the temperature
in case for high or low temperature by control panel. This will achieve high comfort and
control over the humidity.
Control
Control is achieved when a signal is sent to the air conditioner. This enables different
results as desired by the occupant. It can be manual or automatic to control in order to
provide comfort, safety and energy efficiency. An Individual can adjust the temperature,
humidity of air, speed of air condition, pressure of air, and can switch the control on or off.
Adjustment can be done for damper whether one requires it to be closed or open, with the
control for volume of air purpose. Sometimes air conditioning has their own sensor to
control the damper by seeking volume of the room temperature or volume of the room. For
example, if the outside air temperature drops very low, the system adjusts to prevent the
mixed air temperature from dropping below a certain set point.
15
Multi Zones Variable Air Volume
Figure 4: Multi Zone Variable Air Volume
From our research, Tesco Extra uses multi zones variable air volume. Air Handling Unit is
used to supply chilled air through the ducting. The air is then distributed throughout the
whole building. Each zone contains the same temperature and it depends on the individual
comfort to adjust them through a control panel. This can be observed easily in the separate
retail areas and corridors in Tesco Extra.
The system requires installation of a motorized damper for each zone as well as associated
sensors and controller. A thermostat is required to control each pair of zone dampers.
Minimum ceiling space requirements is preferable for the multi-zone system as it allows the
system to operate smoother and with less noise compared to single zone. Basically, the
office (closed area) and the supermarket have different temperature needs. With multi
zones, temperature can be adjusted from warm and cold air that have been mixed and
produced for a comfort purpose.
Mixing is done at the AHU and connected to the control panel. Variable Air Volume is used
to save more energy because the speed can be controlled depending on the demand. But
as per our observation, Tesco Extra has several ducting due to multi zoning. During a
sunny day, Tesco Extra will increase the speed however at night the speed will be reduced.
If one zone needs medium temperature, both cooling and heating coils will work together
and produce same power. However if one desires the room to remain cold, cooling coils will
use more power to enable cooling.
16
Fire Protection System
Photograph 5 : Plan view of 1st
floor in Tesco Extra
Tesco Extra provides various types of fire protection services; the first is that fire
extinguishers are available throughout the whole building in both floors near potential fire
hazards. There are 2 types of fire extinguisher available in the building which is CO₂ Fire
Extinguisher and Dry Powder Fire Extinguisher. CO₂ fire extinguisher is suitable for
flammable liquids, electrical equipment and cooking oils & fats (Fire Equipment
Manufacturers' Association, 2015). It is red in color with a black stripe and there are five
numbers of CO₂ fire extinguishers throughout the building which is located in the Kitchen,
the Genset room, the Switch room, the Computer room, and in the Bakery. They are placed
in such locations to match the type of fire expected which are mostly causes by cooking oils
& fats and electrical equipment.
17
Figure 5: CO₂ Fire Extinguisher
Photograph 6: Dry Powder Fire Extinguisher
On the other hand, Dry Powder fire extinguishers are suitable for solids, flammable liquid,
flammable gasses, and electrical equipment (Fire Equipment Manufacturers' Association,
2015). It is red in color with a blue stripe and is separated evenly throughout the whole
building with a total number of 40 Dry Powder fire extinguishers. It is placed in general
locations with solid objects, liquids and gasses so that when there is an outbreak of fire, the
occupants will be able to use the fire extinguisher to put out the fire.
Fire extinguisher must be generally located close to the proximity of fire hazards so that
when there is an outbreak of fire, it would be easier to be put it out before it turns into a full
scale fire. It is not used for large fires as it is not effective and as it is made for the purpose
of initial outbreak of fire. The placement of the type of fire extinguishers is determined by
the type of fire anticipated. If it used for the wrong type of initial fire, instead of eliminating
the fire, it might make the situation worst.
18
Photograph 7: Hose reel and fire extinguisher
located inside the cabinet with a break glass and fire alarm above
Photograph 8: Sign boards high above on the
wall to easily locate the cabinet
Another type of fire protection which is installed in the building is the fixed type of hose reels
and they are fixed to the wall of the building (Grundfos Holding A/S, n.d.).There are a total
of 9 hose reels available in the building. The hose reels are located at areas which can be
easily spotted and it is painted red so that it can catch the attention of the occupants. There
are sign boards above the hose reels and fire extinguishers so that occupants are able to
identify the location the equipment. Hose reels are normally placed with a fire extinguisher,
a Break Glass, and an alarm bell. The hose reel consist of a hose reel pump, hose reel
tank, pipework and valves. During early stage of a fire, occupants may use the hose reel to
control the fire before the fire brigades arrive.
Break Glass is a component that acts as an active fire protection system which requires the
help of people to start an alarm during the event of fire. Break Glass are fixed together with
the alarm bell and is distributed evenly throughout the whole building. The Break Glass is
installed at a height of 1.2m above finishing floor level for the occupants to reach it with
ease. During the event of a fire, occupants can manually break the Break Glass and trigger
a fire alarm so that the others are aware of the event of a fire. Fire alarm bells should have
a 65dB(a) or +5dB(a) sound pressure and last more than 30 seconds.
19
Photograph 9: Fire Escape with “KELUAR” sign
Photograph 10:Smoke detectors and sprinklers
which is noticeable by the red paint
Fire escape exits are available throughout the building and the door is constantly locked.
During the event of fire, occupants need to unlock the door and use the nearest fire escape
exit. The fire escape exit is made out of fire resistant walls which will enable the occupants
to evacuate within a limited time. There are “Keluar” signs near the fire escape exit which
will light up when the power of the building is cut off so that the occupants are able to find
the fire escape exit.
In addition, smoke detectors are used in the building to detect smoke and initiate the alarm
(Woodford, 2015). Tesco Extra is using ionized smoke detector; the ionized smoke detector
constantly ionizes the air to encourage small electric current. When smoke enters the
detector and reaches the chamber, it reduces the current and activates the alarm.
There are sprinkles installed evenly throughout the whole building. The building is using a
wet sprinklers system as it is constantly filled with pressurized liquid which expand when it
receives pressurized liquid which expands when it receives heat. During the event of a fire
the pressurized liquid would expand until a certain point and it will break the glass tube at
the head of the sprinkler. The plug will be forced out by the pressurized liquid and the water
will be sprayed from the sprinklers head until the main valve is shut off.
Lastly, the Genset room is equipped with an automatic CO₂ system which will flood the
whole room with CO₂ in a delay of 30 seconds and will cool down the electronic machines.
Occupants or workers must evacuate from the room when the CO₂ system is activated as it
can cause insufficiency of air and may lead to death. The main purpose of the CO₂ system
is to protect the electrical devices in the Genset room and prevent the spreading of fire to
another area.
20
Vertical Transportation
Escalator
Figure 6: Escalator
Walking can sometimes be very tiring after a long day of work. In the modern day, every
human being whether or not a doctor, teacher, fireman or a student, are obliged to have a
decent amount of walking time in a day. The invention of a moving walkway called the
escalator is the simplest solution to these problems. Escalators are an essential service
provided as a conveying transport designed for moving people in a more efficient manner
between floors of a building. It is a simple variation on the conveyer belt. A pair of rotating
chain loops pulling a series of stairs in a constant cycle, making it a really convenient and
efficient way of travelling in buildings by moving a big number of people in a short distance
at a decent speed. This simple yet expensive machine also requires zero waiting time.
21
Figure 7: Main Components of an Escalator
1. Electric Control 2. Drive 3. Main Shaft 4. Handrail Drive
5. Balustrade 6. Main Truss 7. Steps 8. Step Chains
9. Handrail Compensation 10. Chain Tensioning Device 11. Comb Plates 12. Handrail Return
A typical escalator normally runs at a speed of 0.45m/s – 0.60m/s, through a 100
horsepower motor, which rotates the gears. The core of an escalator is a pair of chains,
looped around these two pairs of gears. An electric motor turns the drive gears at the top,
which rotate the chain loops. Both the motor and chain system are housed inside a metal
structure extending between two floors called a truss. To create a stable surface to step on,
at the top and bottom of the escalator, the steps collapse on each other, creating a flat
platform. This makes it easier to get on and off the escalator.
Escalators are used all around the world to move pedestrian traffic in places where
elevators would be impractical, for instance, a two storied shopping center. Principle areas
of usage include shopping centers, airports, transit systems, hotels, trade centers, public
buildings and many more. The mechanics to an escalator is very simple as the steps are
constantly rotated to provide continuous flights for pedestrians. Each step in the escalator
has two sets of wheels, which roll along two separate tracks. The upper sets are connected
to the rotating chains, and so are pulled by the drive gear at the top of the escalator. The
other set of wheels glide along the tracks, following behind the first one. The tracks are
spaced apart in such a way that each step will always remain level. Each step has a series
of grooves in it, so it will fit together with the steps behind it and in front of it during this
flattening.
22
Photograph 11: Handrails of a Travelator
The handrail on the other hand, is moved by the provided electric motor. The handrail is
made of rubber, which is looped around a series of wheels. This belt is precisely configured
so that it moves at exactly the same speed as the steps, to give pedestrians stability.
Escalators can be arranged in so many different ways, depending on its usage to the
building. The arrangement of the escalators can be in a one-way traffic or a two-way traffic
system:-
ONE-WAY TRAFFIC (Interrupted Arrangement)
Figure 8: One-Way Traffic Escalator
While relatively inconvenient for users, for the owner of the stores from existing buildings for
example, a shopping complex, it provides an advantage as customers have to walk past
specially placed merchandise displays due to the spatial separation of the upward and
downward directions.
23
TWO-WAY TRAFFIC (Parallel, Interrupted Arrangement)
Figure 9: Two-Way Traffic (Parallel)
This arrangement is used mainly in department stores and public transportation buildings
with heavy traffic volumes. When there are more than 2 escalators, it is possible to reverse
the direction of travel depending on the traffic flow.
TWO-WAY TRAFFIC (Crisscross, Continuous Arrangement)
Figure 10: Two-Way Traffic (Crisscross)
This type of installation is most frequently used as it allows customers to travel quickly to
the upper floors without any waiting time.
24
Application of Vertical Transportation at Tesco Extra
Photograph 12: Floor Plan of Tesco Extra
In the case of Tesco Extra, the building only has two and a half floors whereby the half
floor, being named Mezzanine floor, only has 4 shops compared to the vast amount of
retails provided in the ground and first floor. For a renowned hypermarket store like Tesco
Extra, it is extremely vital for the design team to plan, arrange and provide efficient vertical
transport to the building.
Photograph 13: Travellator at Tesco Extra
To travel from the ground to first floor, the building acquires the use of an inclined moving
walkway. A moving walkway is also known as a travellator. It is very similar to a normal
escalator. The main difference of an escalator to a moving walkway is that it provides a flat
platform throughout the whole transportation system in comparison to the steps provided by
escalators. This system provides the same function as an escalator, which is to transport
people across an inclined plane over a short to medium distance by using a conveyor
mechanism. This system suits the requirement for Tesco Extra, as customers of the
hypermarket are bound to be pushing their trollies full of groceries to their respective cars.
25
The provision of these moving walkways could help the customers save energy by reducing
the amount of effort in pushing the trollies from a fair amount of distance considering the
load bearing of the trollies. These moving walkway machines are provided at both ends of
the rectangular shaped building, which is very much as efficient as it can get.
Photograph 14: Escalator at Tesco Extra
To get to the Mezzanine floor, a normal sized two-way traffic escalator flight is installed for
the use of the customers of Tesco Extra. A moving walkway is not required around this area
as trollies are prohibited within the Mezzanine floor area. The arrangement of both the
escalator and travellator in Tesco Extra use two-way traffic system. During the course of
emergencies or a case of a very heavy pedestrian traffic, both the escalator and the
travellator directions could be adjusted to suit the traffic flow. This gives precision to
travelling within the building.
26
Elevators
Photograph 15: Elevator in Tesco Extra
Photograph 16: Service Elevator
An elevator is a platform, either open or enclosed, which is used for lifting of people or
freight to upper floors within a building. Elevators are a standard part of any tall commercial
or residential building. Factors that affect the number of lifts in a building are: -
1. Population of the building
2. Type of building occupancy
3. The starting and finishing times of the population, whether staggered or unified.
4. Number of floors and heights.
5. Position of building in relation to public transport services.
General specification of a lift car should be able to carry 21 ~ 24 passengers, lift entrances
are about 1100 ~ 1200mm wide with 2 pieces of doors, door closing time should take 3.1
seconds for 1100mm width door and 3.4 seconds for 1200mm doors, transfer time of
passengers are about 1.6 ~ 2.0 seconds in and out, and the acceleration of lift car is
1.0m/sec2.
27
Type of lift Car speed (m/s)
Passengers, up to 4 floors 0.3 ~ 0.8
4 ~ 9 floors 0.8 ~ 2.0
9 ~ 15 floors 2.0 ~ 5.0
Over 15 floors 5.0 ~ 7.0
Paternoster Up to 0.4
Goods, to any height 0.2 ~ 1.0
Hydraulic, passengers or goods, max 4 or 5 floors 0.1 ~ 1.0
Table 2: General specification for car speed of a lift
A round trip time is basically the time in seconds taken by a single lift to travel from ground
floor to the top floor, including the probable number of stops, and return to the ground floor.
The flow rate percentage (%) of the total population requiring lift service during a 5 minute
peak demand period is 10 % to 25 %. If flow rate is not given for staggered starting time, it
is assumed to be 12 % and if flow rate is not given for unified starting time, it is assumed to
be 17 %.
There are 2 main types of elevator available in Tesco Extra, which are hydraulic and
electric elevators. Electric elevator is a type of vertical transport equipment that efficiently
moves people or goods between floors of a building. It is powered by electric motors that
either drives traction cables or counterweight systems. Hydraulic elevators are elevators
which are powered by a piston that travels inside a cylinder. An electric motor pumps oil
into the cylinder to move the piston. The piston smoothly lifts the elevator cab. Electrical
valves control the release of the oil for a gentle descent.
1. Control System – Located in a machine room above the elevator shaft.
2. Electric Motor – Motor rotates and the sheave will either raise or lower the elevator.
3. Sheave – A pulley with grooves around the circumference. The sheave grips the hoist ropes, and it moves as the sheave is rotating.
4. Counter weight – Weighs about the same as the car filled to 40-percent capacity, mainly to balance the speed of elevator when it goes too fast.
5. Guide rails – Along the sides of the elevator shaft, to prevent the car from swaying back and forth, also work with the safety system to stop the car in emergency.
Figure 11: Electric Elevator
28
In Tesco, there are 2 different types of elevators to serve different purposes. The first one is
an electric type which is to carry customers or workers to different levels in the building and
another one is the freight elevator which is to transport trolleys from basement floor to
levels above for shopping purpose. Electric elevator is only provided at 1 side of the
building while the escalator is provided at another side of the building. The arrangement of
escalator and elevator is considered good to provide vertical transport at both different
entrances. But the problem comes in during peak hour, as a lot of people have to wait at
the elevator for a long time since only 1 elevator is provided and the car lift is small and is
unable to carry a lot of people at once. It also cannot be easily found as the elevator is
placed behind a wall.
1. Tank - Shall have sufficient capacity to provide an adequate reserve to prevent the entrance of air or other gas into the system.
2. Motor - Used in hydraulic elevator is constantly pushing Liquid into the cylinder to lift the elevator.
3. Valve - Let liquid out of system, keep the pressure low when open & increase pressure when closed.
4. Actuator - The device that transfers fluid or electrical energy into mechanical energy.
Figure 12: Hydraulic System
29
Electrical Supply
Electrical System
Figure 13: Electrical Distribution Grid
Figure 13 shows the design for electrical distribution for a city or a town. Electricity is
generated from the generating station or power plant (Brain & Roos, 2015). There are a few
types of generating stations some of which are thermal power plant, hydropower plant and
nuclear power plant. The power travels through a distribution grid that works by dividing the
electrical power into networks which then supplies electrical power to every building in the
vicinity.
30
Transformers
Figure 14: Transformer
The transformer is an apparatus used to convert the system’s voltage to increase the
efficiency of distribution for each respective area as per Figure 14. Substations may include
transformers that reduce the voltage of two different transmission voltages. Electrical
transformers can be configured as either a single-phase or a three-phase configuration.
There are several necessary specifications to specify when it comes to electrical
transformers. These include: maximum secondary voltage rating, maximum secondary
current rating, maximum power rating, and output type. An electrical transformer may give
more than one secondary voltage value. Output choices include AC or DC.
Figure 15: Step-Up Transformer
Figure 16: Step-Down Transformer
The transformers can perform both step-up and step-down depending on how it is built. The
transformer increases the voltage from high to low of the electricity being supplied by
increasing the number of coils and decreases the voltage by reducing the number of coils
as per Figure 15 and Figure 16 respectively (Electrical4U, 2015).
31
Service Entrance
Figure 17: Service Entrance
The service entrance is the point where electricity enters the building, which in this case
would be Tesco Extra. It is the directly linked to the TNB substation and is located in Tesco
Extra. A grounding system is used that acts like a drain for current to flow into the building.
The grounding system consist of two parts which are the equipment grounding conductors
and earth grounding conductors used for ground fault protection and dissipating induced
voltages and surges respectively. Although TNB substation is located in the premises of
Tesco, no personnel can simply enter without the permission of TNB.
32
Main Switchboard
Photograph 17: Main Switchboard 1
Photograph 18: Main Switchboard 2
Photograph 19: Main Switchboard Room
The main switchboard (MSB), as shown in
Photograph 17 and
Photograph 18, is an important part of any electrical installation and is generally where the
service protection device and supply authority metering equipment is located. The main
switchboard is located inside Tesco Extra at the point which incoming power supply
distributes throughout the building (Schneider Electric, 2015). It distributes the large
incoming power supply into a smaller form that can be easily controlled. Protection is also
provided; tripping the breakers for when current overloads or short circuits.
33
Distribution Panel
Figure 18: Example of Distribution Panel
Photograph 20: Distribution Panel in Tesco
The diagram above shows one of the many distribution panels in Tesco. It is usually
positioned in strategic locations all around Tesco and fixed to the wall. It is used to
distribute power to consuming appliances while providing a fuse or circuit breaker for each
circuit. The distribution panel normally comes with a metre for when the power oversupplies
and actives the circuit breaker to trip. Circuit breakers are automatic protection devices in
the distribution panel that turns off a circuit when they detect an overload. Circuit breakers
are similar in size to fuses, but gives better protection. When they trip, you can simply reset
the switch whereas fuses need to be replaced when there is an overload.
Requirements of Electrical Installation
There are some factors to be considered before installing the electrical system in a building
and Tesco has satisfied all of the some of which are enough capacity for purpose, minimum
wastage of current, prevention of fire, isolated and corresponding with laws and regulations.
As stated in the Uniform Building By Law 2012 Amendments on EE Bylaw 38A and
MS1525, 7.5, power factor correction capacitors should be the low loss type with losses per
kVAR not exceeding 0.35 W at upper temperature limit excluding the losses in the
discharge resistors. This is to reduce the energy lost in the capacitors and cables. It is also
written in 7.6, that to facilitate monitoring of energy consumption and energy management,
electrical energy meters should be installed at strategic load centre to identify consumption
by functional use (air conditioning, lighting, etc) (Izdihar, 2013). This is to effectively record
and control the usage of the electrical energy.
34
PART 3 – RECOMMENDATION AND SOLUTION
Fire Protection System
There are various fire protection services installed in the vicinity of Tesco Extra such as the
two types of fire extinguisher, fire escape, hose reel, alarm bell, smoke detector and
sprinklers. Despite having sufficient fire protection, the building can be further improved to
withstand the disaster of a fire. Compartmentalisation should be included to help prevent
the spread of fire.
Even though Tesco Extra has taken the measures to provide plenty of sprinklers in the
building, there are times when a sprinkler can fail to douse the fire. The top five reasons
that sprinkler systems failed to operate or were ineffective during a fire were (Long, et al.,
2010):
1. System shut off (38%)
2. Inappropriate system for the type of fire (18%)
3. Water discharged did not reach fire (12%)
4. Lack of maintenance (12%)
5. Problem with water supply or not enough water discharged (9%)
Photograph 21: Food Court
Photograph 22: Bakery
As you can see from Photograph 21 as well as Photograph 22, Tesco Extra has a kitchen
that cooks and bakes freshly made food. If a fire were to ever occur in the kitchen and the
sprinklers were ineffective, the initial fire may erupt into a large scale fire and spread to
different areas and floors. Fire Compartmentation is designed to contain the fire to within
the area of starting point of the fire (A L Fire Systems, 2014). Compartmentation can help in
delaying the spread of fire before the fire brigade arrives to the location.
35
According to COPHK Part 4.14, low rise commercial buildings are required to install
‘Automatic Actuating Devices’ (Fire Services Hong Kong, 2012). Fire shutters can be
installed in the premise to help satisfy the requirement. Modernised fire shutter can now
close at a controlled speed (typically 10 centimetres per second). With a combination of a
Fire Detection Interface (FDI) panel it is now possible for a fire roller shutter to initially
deploy to a pre-determined safe height, (normally just above head height) to act as a smoke
barrier while allowing people to escape (HVP Security Shutters , 2015).
The fire shutter is fully closed after a pre-determined time (following fire protocol for the
building) to create a fire resistant barrier. The FDI panel can also act as a visual and
acoustic alarm, alerting occupants that the fire shutter is about to close (HVP Security
Shutters , 2015)
36
Vertical Transportation
Escalator/Travellator
A simple recommendation to the vertical transport of the building would be to adjust the
direction of the two-way traffic to only one-way traffic on each end of the building. Instead of
having a travellator moving in different directions at both ends, Tesco Extra could adjust the
travellator on one end going up and the other travellator on the other end of the building to
go down. This could help enhance the number of customers going all the way round the
building. This change to the arrangement of the moving walkway could also inevitably
increase the customer density and thus help boost sales among the retails available inside
the building area.
Elevator
Instead of having an elevator, we propose to have another escalator to replace the area
that the elevator was serving. Escalator can carry more people and save time compared to
waiting for the lift car from other levels to reach. At the same time, it is more spacious to
carry goods bought by customers, especially during peak hour.
37
PART 4 – CONCLUSION
In conclusion, Tesco Extra has fulfilled the requirements of the required building services.
The building is operating a centralized air-conditioning system with a multi zone variable air
volume. This will allow the retail shops within Tesco Extra to adjust the temperature to their
own satisfaction. According to the first floor plan, they have over 40 Dry Powder fire
extinguishers, 5 CO₂ fire extinguishers, 9 hose reel, 9 alarm bells and 9 breakglass. Their
premise is installed with an automatic CO₂ at selected areas and a sufficient amount of
smoke detector and sprinklers. Despite that, the fire protection services can be further
improved with the implementation of fire shutters which would compartmentalise the area.
Instead of escalators, Tesco Extra has a travellator to accommodate the use of trolleys and
service elevators to transport the trolleys back into the storage for customers to use. It is
recommended for the travellator to change from a two-way direction to a one-way direction.
This will allows customers to venture and notice the retail stores along the sides of Tesco
Extra.
38
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41
APPENDIX
Job Scope
Abang Azrin Bin Abang Affandi
Vertical Transportation – Escalator/Travellator
Recommendation for Escalator/Travellator
Chua Jia Cheng
Fire Protection System
Goh Jeng Jhieh
Vertical Transportation – Elevator
Recommendation for Elevator
Jake Sia Chyi Sern
Electrical Supply
Kellyann Hiew Yau Mei
Recommendation for Fire Protection System
Structure of the whole Report
Compilation of the report
Muhammad Aiman Bin Zainul Abidin
Mechanical and Air-Conditioning System
Rachel Emma Betty Ernesta
Mechanical and Air-Conditioning System
42
Schedule of Assignment
DATE
Kelly went to site to request for permission. Received no reply
18th of April, 2015
1st discussion, distribution of workload
29th of April, 2015
Sent an email to Tesco Extra. Received reply, but no confirmation
30th of April, 2015
Whole group went to the site to take pictures and gain information of site
7th of May, 2015
Started on report
8th of May, 2015
2nd discussion, checking on each other’s progress
21st of May, 2015
3rd discussion, checking on each other’s progress
13th of June, 2015
Compilation of report
23rd of June, 2015
Submission of report Presentation
24th of June 2015