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Electrical Design For Building Engineering Essay

Electricity is steadily becoming the preferred source of power for lighting, heating, air conditioning, transportation, production equipment, and numerous appliances in all building occupancies.

The nominal use of electrical power in office increased, and statistics indicate that the nominal use of electrical power in offices in terms of Unit Power Density (UPD) has increased from 1 to 3 W/ft square in the 40s, to 3 to 5 W/ft square in 80s, and to 5 to 10 W/ft square in 90s.

While after the 90s, peoples realised that the extremely power usage within a building and try to make a solution to it. With improved technologies and concerted effort in energy conversion design, the UPD in modern buildings has actually dropped to below the 90s level while the use of electrical equipment continues to be expanding.

One unique characteristic of the electricity is that it can transmit through a relatively small space by means of wires and cables. The amount of power that can be transmitted by a particular wire depends on the voltage level, such as 480 V for large equipment or accessory and 120 V for small appliances. While inside some large buildings, even voltage up to level of 34,000 V have been used directly with spaces designed to accommodate them.

The flow of electrical current is proportional to the availability of electrical voltage. Electrical systems with voltage below some 30 V are not easy to pass through the human body and thus are relatively safe to touch. On the other hand, household appliances at 120 V and 240 V may cause shocks or even death. For safety reasons, electrical wiring and equipment are strictly regulated. The primary code governing electrical systems and installations in the Malaysia is the IEEE standards.

Building electrical systems are normally designed by electrical engineers with specialized knowledge of such systems. However, every member of the building design profession must have a fundamental knowledge of electricity and its operating principles, characteristics, and limitation.

TABLE OF CONTENTS

DECLARATION ii

APPROVAL FOR SUBMISSION iii

ACKNOWLEDGEMENTS vi

ABSTRACT vii

TABLE OF CONTENTS ix

LIST OF TABLES xiii

LIST OF FIGURES xiv

LIST OF SYMBOLS / ABBREVIATIONS xv

LIST OF APPENDICES xvi

INTRODUCTION 1

1 Background 1

2 Aims and Objectives 2

LITERATURE REVIEW 6

1 Overview of M&E Systems 6

2 Power Equipment and Systems 9

2.1 Power Distribution Systems 9

2.2 Power Equipment 10

2.3 Conductors 10

2.4 Switches 11

2.5 Protective Devices 11

3 Electrical Design and Wiring 12

3.1 Analysis of Building Needs 12

3.2 Determination of Electrical Loads 13

2.3.2.1 Connected Load 13

2.3.2.2 Demand Load 13

2.3.2.3 Diversity Coefficient 14

3.3 System Selection and Typical Equipment Ratings 14

3.4 Drawing Up Electrical Plans and Specifications 14

2.3.4.1 Graphic Symbols 15

2.3.4.2 Electrical Plans 15

2.3.4.3 Specifications 16

3.5 Physics of Light 16

2.3.5.1 Energy of Light, Q 16

2.3.5.2 Power of Light, F 16

2.3.5.3 Light Power Density: Illuminance, E 16

2.3.5.4 Luminance, L 17

METHODOLOGY 18

1 Calculations of Illumination 18

1.1 Quantity and Quality of Illumination 18

1.2 Evaluating the Visual Environment 19

1.3 Basic for Illumination Calculations 20

1.4 The Zonal Cavity Method 20

3.1.4.1 Light Loss Factor 21

2 Sub-subsection Title 1 21

2.1 Sub-sub-subsection Title 1 21

RESULTS AND DISCUSSIONS 23

1 Subsection Title 1 23

2 Subsection Title 2 23

3 Sub-subsection Title 1 24

3.1 Sub-sub-subsection Title 1 24

CONCLUSION AND RECOMMENDATIONS 25

1 Subsection Title 1 25

2 Subsection Title 2 25

3 Sub-subsection Title 1 26

3.1 Sub-sub-subsection Title 1 26

REFERENCES 27

APPENDICES 28

CHAPTER

INTRODUCTION 1

1 Background 1

2 Aims and Objectives 2

LITERATURE REVIEW 6

1 Overview of M&E Systems 6

2 Power Equipment and Systems 9

2.1 Power Distribution Systems 9

2.2 Power Equipment 10

2.3 Conductors 10

2.4 Switches 11

2.5 Protective Devices 11

3 Electrical Design and Wiring 12

3.1 Analysis of Building Needs 12

3.2 Determination of Electrical Loads 13

3.3 System Selection and Typical Equipment Ratings 14

3.4 Drawing Up Electrical Plans and Specifications 14

3.5 Physics of Light 16

METHODOLOGY 18

1 Calculations of Illumination 18

1.1 Quantity and Quality of Illumination 18

1.2 Evaluating the Visual Environment 19

1.3 Basic for Illumination Calculations 20

1.4 The Zonal Cavity Method 20

2 Sub-subsection Title 1 21

2.1 Sub-sub-subsection Title 1 21

RESULTS AND DISCUSSIONS 23

1 Subsection Title 1 23

2 Subsection Title 2 23

3 Sub-subsection Title 1 24

3.1 Sub-sub-subsection Title 1 24

CONCLUSION AND RECOMMENDATIONS 25

1 Subsection Title 1 25

2 Subsection Title 2 25

3 Sub-subsection Title 1 26

3.1 Sub-sub-subsection Title 1 26

REFERENCES 27

APPENDICES 28

LIST OF TABLES

TABLE TITLE PAGE

Table 3.1: Processing Time (in hours) of Bread for Different Production Line 21

Table 4.2: Processing Time (in hours) of Bread for Different Production Line 24

LIST OF FIGURES

FIGURE TITLE PAGE

Figure 3.1: Reflection from Smooth Surface 22

Figure 4.2: UTAR Logo 24

LIST OF SYMBOLS / ABBREVIATIONS

cp specific heat capacity, J/(kgK)

h height, m

Kd discharge coefficient

M mass flow rate, kg/s

P pressure, kPa

Pb back pressure, kPa

R mass flow rate ratio

T temperature, K

v specific volume, m3

 homogeneous void fraction

 pressure ratio

 density, kg/m3

 compressible flow parameter

ID inner diameter, m

MAP maximum allowable pressure, kPa

MAWP maximum allowable working pressure, kPa

OD outer diameter, m

RV relief valve

LIST OF APPENDICES

APPENDIX TITLE PAGE

APPENDIX A: Graphs 28

APPENDIX B: Computer Programme Listing 29

INTRODUCTION

Background

Electrical design is one of a main engineering field in the society, especially when it refers to construction sector. Hence, in this introduction chapter, it will be explaining why the electrical systems design for buildings plays a main role in the construction field.

M&E system plays a major part in the construction of buildings. As nowadays, modern buildings are no longer just shelters from rain, wind, snow, sun, or other harsh condition of nature. Rather than that, buildings are now built to create better, more consistent, more productive environment, in which we are able to work and also to live a better life.

As the author is involved in the Electrical study only, so this project would only cover the Electrical design. Electrical design for a building will include a lot of different knowledge, for example, electrical power for normal, standby, and also emergency condition inside a building, or the power supply and distribution systems for a high rise building.

In this project the author will only do research on the electrical lighting systems. It will show the importance of electrical lighting design inside the building, interior, exterior, emergency lighting, technical data calculation, and also the drawings of electrical lighting design.

However, a building is not only to provide better lighting, but also comfortable space temperature, humidity and air quality, convenient power and communication capability, quality sanitary system, and reliable systems for the protection of life and property. All of these desirable features have become a reality with recent advance in technology in M&E systems.

All these advances have come with a price. Either of M&E designs, it will demand considerable floor and ceiling space. Without proper space allocation, the design may have to be started all over again, and very often the system performances are compromised.

Figure 1.1: Energy usage inside a building

Aims and Objectives

The aims and objectives of doing this M&E study, is to let the author involved in an industrial based project. As the topic of this study is based on a project that is still under development, the author would have the opportunity to get the latest information and knowledge.

The author would have the chance to become familiar with the M&E services. The experience the author had after completing the topic would help to increase his chance in the job hunting too. While doing this project, a lot of analysis, theories, calculations, and technical will be involved. From there, the author would have the opportunity to solve these problems and finally these problems will become the experience for author to use in the future.

Some of the common problems are like, impact of space planning, impact of architect design, impact of construction cost, impact of high-rise building design, energy and energy conversion, impact of buildings on global environment, environment responsive and integrated designs, system interfacing, checklist of building and M&E requirements, and also the building design and construction process.

All these common problems during the M&E design are very important. All these factors will affect the overall design, and it need to be taken care of before the author carry out any drawing. If any thing goes wrong during the process, it will not only affect the performance of the building’s M&E system, but may cost a very huge impact on the construction of the building.

Those impacts may exists in different forms, such as financially lost, more time consuming and time losses, contract broken and reputation damaged, argument and relationships threaten, and also professionally failure as an engineer. Because of that, the author who acts as an engineer shall take those problems seriously and analyse them carefully with his professional point of view before indicating any design.

Besides all these common problems in the M&E systems, there are others more specific problems for the author to solve too. This project’s topic is more towards the electrical design, especially in the lighting field. So, there will be a lot of theoretically, calculation, and practical drawing regarding to the lighting theory and design.

While doing the lighting design, there are a lot of factors to be taken care of. Such as the electrical design procedure, analysis of building needs, determination of electrical loads, system selection and typical equipment ratings, coordination with other design decisions, drawing of electrical plans and specifications, national electrical code, branch circuits, tables and schedules, power wiring design problem, and also the wiring of low voltage systems.

Besides that, the author shall need to know the basic and fundamental of lights, and also understand more specific about the light and lighting theories. This will include the light and energy spectrum, physics of light, vision and visible spectrum, colour, and light control.

After become familiar about the electrical and lighting theories, the author will start to learn about the lighting equipment and systems theories. Lighting equipment and system will be include the electrical light sources, factors to consider in selecting light sources and equipment, incandescent light sources, fluorescent light sources, high-intensity discharge light sources, miscellaneous light sources, general comparison of light sources, and luminaries.

After the author understand the theories of lightings and its equipment. The author will start to do the calculations part, and it is called as calculation of illumination. The calculations of illumination will be covering the quality and quantity of illumination, evaluating the visual environment, luminance categories and recommended luminance levels, basic for illumination calculations, the zonal cavity method, application of the zonal cavity method, point method, and computer calculation and computer-aided design (CAD).

The calculations for the building’s lighting system will contribute to the design. The author will get a better view of the system as a whole, and uses the calculation value and statistic to do the designing. The lighting design will be include the factors such as, design consideration, lighting design development, lighting design documentation, daylight, exterior lighting design, and also the design practice and alternative solutions.

This project will enable the author to have the ability to implement a project starting from the beginning to the end. Although the condition of each cases maybe different, however the basic within will still be the same. The author can use the experience and problem solving skills from this project to improve himself for his future.

In the next few chapters, it will involve more about the theory of lighting design inside a building. It will be covering more details and information for each of those objectives stated earlier. After that, the last two chapters will include all the results, findings, calculations and also the AUTO-CAD lighting design that the author had done. Lastly, the final chapter will be the conclusion.

LITERATURE REVIEW

Overview of M&E Systems

M&E systems in a building had a big impact on space planning. The floor area necessary for M&E systems varies widely, depending on the occupancy, climatic conditions, living standards, and quality and general architectural design of the building. Reasonable allocations made during the space programming phase allow M&E space to be appropriately sized and strategically located. This Table 2.1 below shows some examples of M&E systems required floor area for various buildings.

Table 2.1: Range of M&E Floor Area Require for Buildings

Type of Occupancy

Percentage of Gross Building Area, %

Low

Medium

High

Computer centres

10

20

30

Department stores

3

5

7

Hospitals

5

10

15

Offices

2

4

6

Residential, high-rise

1

3

5

Retail, individual stores

1

2

3

Schools, elementary

2

3

4

Schools, secondary

2

4

6

University and colleges

4

6

8

Most modern buildings are influenced by the presence of M&E systems. Some typical examples are the KL tower and TWIN tower in our country. In high-rise building, the M&E problems on different site may favour different M&E solution. There is no single solution to a problem, the climate, economic, and cultural background of a country will affect the selection of M&E systems. However in this project, it will only be a 3 stories building instead of high-rise building, hence less complexity.

All building required electrical power, which is normally supplied by the electrical utility. When utility power is not available, or the on-site electrical power source is required, the supply of fuels such as gas, oil, and even coal may need to be considered in the planning process. In addition, renewable power source is also a very good choice to choose from, especially when the government is promoting Green Building. Building electrical system would include power, lighting, and auxiliary systems. The electrical and electronics systems in the building applications has greatly expended the scope of electrical systems and had a dramatic impact on construction costs and the complexity of planning.

Table 2.2: Checklist of Electrical Systems

System/Function

Major Planning Considerations

Normal power source

Utility or on-site power, substations, etc

Power distribution

Primary or secondary voltages, panels, and substation

Emergency power distribution

Critical equipment/building loads, emergency lighting, power sources (batteries, UPS, etc)

Major lighting system

Light sources and method of mounting

Lighting design and layout

Light sources, fixture selections, layout, and controls, etc

Emergency lighting

Exit, exit way, critical, and emergency, etc

Feature lighting

Architectural expression and building features, etc

Day lighting

Fenestration, skylights, controls, etc

Exterior lighting

Site, landscape, building facade, security, etc

Automatic controls

Interface with lighting, security, etc

Table 2.2 shows a checklist of normal lighting equipment and requirement of an electrical system inside a building. Checklist serves to determine the scope of building operational requirements and from which one can determine the scope and criteria of M&E systems. The checklist also is valuable in formulating the architectural concept, building configuration, space planning and opportunity for system interfacing.

Whether the project is complex or a simple building, there must be three basic players, the owner, the designer, and the constructor. Each is responsible for performing a specific set of functions.

Figure 2.1: Project Realization stages

Figure 2.1 shows an example of project realization stages for a building. Designer or the consultant such as electrical engineer play a very important part in realizing the needs of the owner and also fulfilling the requirement set by the government. Neveen Hamza & David Greenwood (2008) found that during the design phase, the M&E consultant must ensure that:

Building envelope design limits heat loss or gain through the building fabric;

Solar gain and heating gains are considered in an attempt to remove reliance on air conditioning systems where natural ventilation can be used;

Availability of passive ventilation systems is ensured where air conditioning is not used;

Energy efficient building services systems and insulated duct work are specified;

Energy efficient building services controls are specified;

Attention is paid to decreasing thermal bridging and uncontrolled air infiltration;

Performance of the whole building is then checked based on a comparison between a target annual carbon dioxide emission rates (TER) and the actual building design performance. The intended design should deliver reductions in the TER of between 20 and 27% from a notional building.

The building as designed is then simulated – using the same accredited package as in the TER – to ensure that it achieves comparable or better the performance of the TER.

Power Equipment and Systems

Power Distribution Systems

Inside a building there are numerous of power distribution systems being used. The systems being used will depend on the size of the building and also the characteristics of the predominant loads, such as the power requirement of the equipments, voltages, and phases. Frequency is also an important characteristic and country like Malaysia is using 50 Hz. Most buildings contain loads with diversified characteristics, such as single phase lighting and appliances and 3-phase motor. Thus, it’s quite normal to have more than one power distribution systems in the same building. For this project, it will be using the low and medium voltage system. While the utility - TNB will regulate their supply voltage from their power plant and the distribution substation to within 1 percent of nominal voltages.

Emergency power systems are required by building codes to ensure the continuity of a building when a loss of normal power may create danger to people, fire hazard, or loss of property or business. Normally, three types of emergency power supply are in common use. Tap ahead of main switch, on-site generator, and separate power source. On-site generator meaning one or more electrical generators will be installed. When the building losses power supply, it will automatically provide power to the loads. This is the most reliable, but it is more costly to own and maintain. For example, Tunku Abdul Rahman College is using an on-site generator which located near to their canteen.

Power Equipment

There are levels of equipment in an electrical power system, starting with the power service, transformers, and distribution equipment and ending with the load-end protection devices. Utility power may enter a building through an overhead for small voltage system or underground duct for large systems. Then, it will be reduced to the utilization voltage through a transformer. Transformers are power transmission equipment primarily intended to convert a system’s voltage from one level to another, whether to step-up or step down.

Switchboard is an assembly of switches and circuit protection devices from which power is distributed. The switchboard serves as the main distribution centre of a small system or as a portion of the distribution centre of a large system. While panel board is an assembly of switches and circuit protection devices as the final serving point of the distribution system.

Conductors

Cable is to carry current between source and utilization equipment. In carrying this energy, there will be heat losses generated in the cable. Ability to dissipate these heats will be depending on how the cables are installed, and this affects their ratings.

The selection of conductor size requires consideration of the load current to be carried and the loading cycle, emergency overloading requirements and duration, faults clearing time and interrupting capacity of the cable over current protection or source capacity, voltage drop, ambient temperatures, circuit length through hot ambient temperature, and system frequency. All these statistics can be found in the TNB’s standard book.

Switches

Various wiring devices, from switches, receptacles, and over current protection devices to contactors and dimmers are used in electrical systems. All wiring devices must be installed in code approved boxes, regardless of the wiring systems.

A switch is a device for making, breaking, modulating or changing the connections in an electrical circuit. Light switches are normally single-pole, single throw switches. When lights need to be switched from more than one location, three-way or even four-way switches are used.

Receptacle is a wiring device installed within an outlet box for the connection of electrical apparatus through an attachment plug. Receptacle is classified by the characteristics, number of receptacles, current rating, voltage rating, number of poles and wires, shape of the blades, and configuration of the blades used.

Contactors and relays are remote control power transmitting devices and normally used to carry line or low voltage power. Dimmers are operating devices tat reduce the input and also the output of an appliances. In this case, the dimmers can be used to control the lighting devices power output, and hence controlling its luminance.

Protective Devices

Inside an electrical circuit there will be feeders, distribution equipments, branch circuits and the load equipments. They must be protected from exceeding their rated capacities, which may occur from certain circumstances, such as over current, over voltage, and reverse in polarity of a three-phase system. The most common method used to prevent the damage caused by the overloading is to install some protective devices at strategic locations. These devices are divided into three general types, relays, circuit breakers, and fuses.

Relays are normally used by utility companies to protect their primary distribution system or equipment. A circuit breaker (CB) is a device that designed open the circuit automatically on a predetermined over current, without damaging the appliances. Three are three types of CB, low voltage power circuit breakers, insulated case circuit breakers, and molded case circuit breakers (MCCB). Nowadays, CBs are universally used for lighting and receptacle panels. A lot of these CB protective devices will be seen during the lighting design for the building.

While the fuse is an electrical protective device that melts upon the sensing an abnormal current and opens the circuit in which it is installed. Fuse is classified as its voltage class, current rating, construction, principle of operation, short circuit interrupting capacity and fusible material.

Electrical Design and Wiring

Electrical system design is an integral part of the overall building design process. Unfortunately, more often than not, these electrical operating devices, such as switches, receptacles, controls, and alarms, are installed indiscriminately, without regard to their location, size, shape, or color.

There are 5 steps in electrical design are analyze building needs, determine electrical loads, select electrical systems, coordinate with other design decisions, and prepare electrical plans and specifications.

Analysis of Building Needs

In this case, the building is used as place for study, so the factors affecting the electrical design are the student’s and teacher’s requirements. Cost will not be a problem and having an average quality of electrical system.

The building environment and architecture design – the classroom lighting level, light sources, floor height, area, size of building, floor levels, and etc. Building equipment such lights at the corridors, classrooms equipment, staffs room and toilets lighting, play ground and gym special lighting devices and etc. All these factors must take in account to design the best lighting design for each area.

Determination of Electrical Loads

Connected Load

Lighting systems is usually the coordinated effort of the architect, interior designer, electrical designer and electrical engineer. Lighting accounts for one of the larger electrical loads in most buildings. In general, lightings are designed for 120 V, single phase power. Continuity improvement has also increased the efficiency of converting electrical energy to lighting. Loads of lighting devices can be describes as:

TCL = CL1 + CL2 + CL3 + CL4 + …. + CLN

= ∑ CLN (2.1)

where

CL = connected load (light)

TCL = total connected loads

∑ CL = sum of all connected loads

Demand Load

Demand load of an electrical power system indicates the net load that used at the same time. Sometimes, the practical usage of the lighting system will not be 100 percent, and the percentage will be called as demand factor.

DL = CL x DF (2.2)

and

TDL = ∑ DL (2.3)

where

DL = demand load

DF = demand factor

TDL = total demand loads

∑ DL = sum of all demand loads

Diversity Coefficient

The diversity coefficient accounts for the diversity of demand between groups of loads. Diversity coefficient also called as diversity factor (DF). The DF is time consuming to calculate, and often it is neglected by designers, hence causing an oversized system. In this project, the DF used will be according to the advice from author’s supervisor.

System Selection and Typical Equipment Ratings

In actual design, M&E engineer must weigh the various factors in alternative systems before making the final decision, which include the cost of investment and maintenance, systems reliability, serviceability, space availability, and impact on other system.

Example is a power system, three-phase or single phase must be chosen base on the load characteristic. While in this topic, it will be using a three-phase system, as it could serve up more lighting devices.

Drawing Up Electrical Plans and Specifications

Graphic Symbols

Graphic symbols are used to indicate various aspects of electrical design. Without these symbols, electrical design will be very difficult to illustrate. Standardized symbols are intended to use, however, TNB has not kept with the growth of electrical systems. As a result, many customized symbols have been developed. Figure 2.2 shows some examples of legends used in Malaysia.

Figure 2.2: Example of legend use in Malaysia

Electrical Plans

Electrical plans are usually consists of floor plans, schematic diagram, wiring diagram, single line diagram, and riser diagram. In floor plan, electrical devices are superimposed on architectural background. Example, if the roof is very high, special lighting devices will be used compare to normal fluorescent light.

Schematic diagram and wiring diagram illustrate the circuitry of the system, connections between the wiring terminals of devices, and they are the basic for understanding the functions of the electrical system.

Single line diagram is a simplified system diagram that shows the principal relationships between the major equipment. The riser diagram expressed the physical relationship between equipment and is used to show the vertical relationship between floors.

Specifications

Specifications are the written design documents. They are usually used together. However in this project, author will not be giving out any specifications details.

Physics of Light

Energy of Light, Q

Light generated in buildings is nearly all converted from electrical energy, and quickly degrades into heat energy. Because it cannot be stored, thus to maintain a certain lighting level for a certain area, electrical power must be supplied continuously.

Q = ∫ Φ dt (2.4)

or

Q = F x t (2.5)

where

Q = luminous energy, lm

Φ = luminous flux lumen, lm

t = time, s

F = luminous power, lm

Power of Light, F

Power is the rate of consuming energy. In lighting, it is the luminous flux emitted by a light source in a unit of time.

F = Φ = dQ / dt (2.6)

where

F = luminous power, lm

Light Power Density: Illuminance, E

Illuminance is the density of luminous flux incident on a surface. It is analogous to W / area in electrical power:

E = dΦ / dA (2.7)

or

E = F / A (2.8)

where

E = illuminance, fc

F = total lumens incident on the surface, lm

A = total are, m²

Luminance, L

Luminance is a quantity that difficult to grasp. It is the brightness of a real imaginary surface or the visual appearances produced by the illuminance. Brightness is a subjective evaluation of a surface, whereas luminance is the objective measured characteristic.

The lighting can be too bright or may come from the wrong direction, causing discomfort or inefficient. The light could also be the wrong colour, causing poor colour discrimination.

Light can be reflected from the surface of a material, is the surface is shiny, such as mirror, then the reflected light should follow the law of reflection. If the surface is not shiny, then the light will be diffused. When the material is transparent, light will pass through it in a controlled mode. Light is absorbed and there will be loss of light. The amount of light absorbed is the balance of the incident light that is reflected or transmitted.

METHODOLOGY

Calculations of Illumination

This chapter covers the procedures for analyzing the visual quality requirements and for determining the quantity of requirements of a specific space or a task. The procedure involves analysis of visual environment, determination of illumination requirements, tentative equipment selection, preliminary engineering calculations, final equipment selection, final engineering calculations, and final equipment layout.

In fact, like other design process, lighting design is a trial and error process. Experience can often used to help the engineer for selecting the most appropriate design and the final layout is much as art as a science.

Quantity and Quality of Illumination

High quality lighting can be cover for the lack of quantity, and vice-versa poor lighting will need higher light quality to improve the performance. Quality of lighting can be quantified, yielding numerical value than can be compared. However, the calculations are usually very complex.

Evaluating the Visual Environment

Before deciding the quantitative requirements for a certain space, design issue must be systematically analyzed and identify each issue’s importance or relevance. The Illuminating Engineering Society of North America identified a series of issues that must be evaluated in the design. The design issue and recommended illuminance categories are:

Design issues:

Appearance of space of luminaires

Colour appearance and colour contrast

Day lighting integration and control

Direct glare

Flicker and strobe

Light distribution on surfaces

Light distribution on task plane

Luminance of room surfaces

Modelling of faces or objects

Points of interest

Reflected glare

Shadows

Source and task geometry

Sparkle or desirable reflected highlights

Surface characteristics

System control and flexibility

Illuminance selection:

Horizontal illuminance

Vertical illuminance

Evaluating of design issues and luminance categories:

Lamp sources – appearances, colour, direct glare, reflected glare, flicker, sparkle, modelling, shadow, system controls and switching flexibility.

Selection of luminaries – appearances, direct glare, reflected glare, light flux distribution, controls.

Layout of luminaries – flux distribution, day lighting, integration and controls, modelling of objects, points of interest, direct and reflected glare, geometry.

However, deign of a lighting system is not just about the lighting quality and quantity, economic and environmental factors should be included too.

Basic for Illumination Calculations

There are two methods to calculate illuminance, first is lumen method. By the equation given (2.4) and (2.5) of chapter 2, light power density or illuminance (E) on a surface is the number of lumens per unit area on a surface illuminated by the light sources. Surface is in units of square meters, so the illuminance will be in lux (lx).

E = F / A (3.1)

where

E = illuminance, lx

Second, is called as point method. The equation given in (2.6), illuminance (E) on a surface is also equal to the light intensity (I) of the light source divided by the square of distance from the surface. Distance is measured in meters, the illuminance is in lux (lx).

E = I / d² (3.2)

Depending on the relative size of the light sources and the receiving surface, either one or both of these two methods may be applicable. Sometimes it is necessary to determine the surface brightness of an illuminated surface for glare control, to calculate the luminance contrast or the luminance difference of adjacent surfaces.

The Zonal Cavity Method

Zonal method is an application of the lumen’s method (3.1) to determine the horizontal illuminance.

Light Loss Factor

There are two factors, unrecoverable light loss factor (ULLF) and recoverable light loss factor (RLLF). ULLF are voltage factor, temperature factor, ballast factor, and luminaries surface depreciation factor. Normally, all these factors reflect little impact on the system and for installation in new building, factor of 1 can used.

RLLF are recoverable factors that can be change by regular maintenance:

Lamp lumen depreciation factor – lamp output depreciates gradually until burns out.

A new paragraph should not begin on the last line of a page. A subsection title should not begin on the last line of a page.

Sub-subsection Title 1

Sub-sub-subsection Title 1

Spacing between title of subsection and first line of text is 1.5 lines. Spacing between the last line of text and table is 1.5 lines.

Table 3.1: Processing Time (in hours) of Bread for Different Production Line

Bread

Production Line

1

2

3

4

5

A

30

18

26

17

15

B

23

22

32

25

30

C

17

31

24

22

29

Spacing between the table and first line of text is 3.0 lines. Spacing between the last line of text and figure is 1.5 lines.

Source

Reflected

Figure 3.1: Reflection from Smooth Surface

Spacing between the figure and first line of text is 3.0 lines. Subsequence paragraphs should be indented 1.27 cm (0.5 inch) from the left margin.

RESULTS AND DISCUSSIONS

Subsection Title 1

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Spacing between paragraphs is 1.5 lines. Subsequence paragraphs should be indented 1.27 cm (0.5 inch) from the left margin. General alignment for texts in paragraph should be “justified”. Spacing between last line of text and the next subsection title is 4.5 lines.

Subsection Title 2

Spacing between title of subsection and first line of text is 1.5 lines. The first paragraph in a subsection should align with left margin. General alignment for texts in paragraph should be “justified”.

A new paragraph should not begin on the last line of a page. A subsection title should not begin on the last line of a page. A new chapter must start on a new page.

Sub-subsection Title 1

Sub-sub-subsection Title 1

Spacing between title of subsection and first line of text is 1.5 lines. The first paragraph in a subsection should align with left margin. Spacing between the last line of text and table is 1.5 lines.

Table 4.2: Processing Time (in hours) of Bread for Different Production Line

Bread

Production Line

1

2

3

4

5

A

30

18

26

17

15

B

23

22

32

25

30

C

17

31

24

22

29

Spacing between the table and first line of text is 3.0 lines. Spacing between the last line of text and figure is 1.5 lines.

Figure 4.2: UTAR Logo

Spacing between the figure and first line of text is 3.0 lines. Subsequence paragraphs should be indented 1.27 cm (0.5 inch) from the left margin.

CONCLUSION AND RECOMMENDATIONS

Subsection Title 1

Spacing between title of subsection and first line of text is 1.5 lines. The first paragraph in a subsection should align with left margin. General alignment for texts in paragraph should be “justified” (Warner, 2002).

Spacing between paragraphs is 1.5 lines. Subsequence paragraphs should be indented 1.27 cm (0.5 inch) from the left margin. General alignment for texts in paragraph should be “justified”. Spacing between last line of text and the next subsection title is 4.5 lines.

Subsection Title 2

Spacing between title of subsection and first line of text is 1.5 lines. The first paragraph in a subsection should align with left margin. General alignment for texts in paragraph should be “justified”.

A new paragraph should not begin on the last line of a page. A subsection title should not begin on the last line of a page. A new chapter must start on a new page.

Sub-subsection Title 1

Sub-sub-subsection Title 1

Spacing between title of subsection and first line of text is 1.5 lines. The first paragraph in a subsection should align with left margin. General alignment for texts in paragraph should be “justified”.

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