borang pengesahan status tesis - Faculty of Electrical Engineering

UNIVERSITI TEKNOLOGI MALAYSIA
` PSZ 19:16 (Pind. 1/97)
BORANG PENGESAHAN STATUS TESIS υ
JUDUL:
______________________________________________________
SMARTS WINDOW FOR ENERGY EFFICIENCY IN
COMMERCIAL BUILDINGS
______________________________________________________
SESI PENGAJIAN:
______________
2007 / 2008
Saya
MOHD AZFAR AMRI BIN ISHAK
________________________________________________________________________
(HURUF BESAR)
mengaku membenarkan tesis (PSM/Sarjana/Doktor Falsafah)* ini disimpan di Perpustakaan
Universiti Teknologi Malaysia dengan syarat-syarat kegunaan seperti berikut:
1. Tesis adalah hakmilik Universiti Teknologi Malaysia.
2. Perpustakaan Universiti Teknologi Malaysia dibenarkan membuat salinan untuk tujuan
pengajian sahaja.
3. Perpustakaan dibenarkan membuat salinan tesis ini sebagai bahan pertukaran antara
institusi pengajian tinggi.
4. **Sila tandakan ( √ )
SULIT
(Mengandungi maklumat yang berdarjah keselamatan atau
kepentingan Malaysia seperti yang termaktub di dalam
AKTA RAHSIA RASMI 1972)
TERHAD
(Mengandungi maklumat TERHAD yang telah ditentukan
oleh organisasi/badan di mana penyelidikan dijalankan)
√
TIDAK TERHAD
Disahkan oleh
____________________________________
(TANDATANGAN PENULIS)
____________________________________
(TANDATANGAN PENYELIA)
Alamat Tetap:
_____________________________________
BLOK F-1-13 PERSIARAN LEMBAH
_____________________________________
PERPADUAN, PERMAI LAKE VIEW,
_____________________________________
31150 ULU KINTA, PERAK
PM. FARIDAH BINTI MOHD
____________________________________
TAHA
Nama Penyelia
Tarikh: ____________________________ 13 th MAY 2008 Tarikh: ____________________________
13 th MAY 2008
CATATAN: * Potong yang tidak berkenaan.
** Jika tesis ini SULIT atau TERHAD, sila la mpirkan surat daripada pihak
berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu
dikelaskan sebagai SULIT atau TERHAD.
υ Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah dan Sarjana secara
penyelidikan, atau disertasi bagi pengajian secara kerja kursus dan penyelidikan, atau

I
SMART WINDOWS FOR ENERGY EFFICIENCY IN COMMERCIAL
BUILDINGS
MOHD. AZFAR AMRI BIN ISHAK
A report submitted in partial fulfillment of the
requirements for the award of the degree of
Bachelor of Electrical Engineering
Faculty of Electrical Engineering
Universiti Teknologi Malaysia
MAY 2008

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“I declare that this thesis entitled “Smart Windows for energy efficiency in
commercial buildings” is the result of my own research except as cited in the
references. The thesis has not been accepted for any degree and is not concurrently
submitted in candidature of any other degree.”
Signature : ……………………………….
Name of Supervisor : MOHD. AZFAR AMRI BIN ISHAK
Date : 13 MAY 2008

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Dedicated, with thankful appreciation for support, encouragement and
understandings to my beloved mother, father, brothers and sisters.

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ACKNOWLEDGEMENT
First and foremost, I would like to express my heartily gratitude to my
supervisor, Associate Professor Faridah bt Mohd Taha for the guidance and enthusiasm
given throughout the progress of this project. Without her ideas and comments
throughout the process of this project, this thesis would not have been the same as
presented here.
I also like to express my thankful to Mr. Hamdan from Tasek Development Sdn.
Bhd. who help me and give his full commitment in getting the data and information
needed about Ang’s building. My sincere thankful also extends to James J.Hirsch from
Department of Energy (DOE) of US who support and advice me in choosing the right
software to use in this project. He also the person who send me the software that I use in
this project (EQUEST v3.6) via email and gave me some guidance to use it.
My special appreciation goes to my family who has been so tolerant and supports
me in completing this report. Thanks for their encouragement, love and emotional
supports that they had given to me. Last but not least my appreciation to all my friends
and SEE members and those whom involve directly or indirectly with this project.
Thank you.

V
ABSTRACT
With worldwide energy cost rising significantly, there has been a pressing need
to reduce the burning of fossil fuels and subsequently energy consumption. This,
coupled with the prospect of global warming threatening human habitation, has made
countries including Malaysia more conscious and aware of the energy problem at hand.
This project deals with smart window, a double glazing unit where one pane consists of
a high-performance heat reflective glass and the other coated with low-emissivity (lowe)
coating. This combination of glazing provides optimum energy efficiency and a high
level of daylight transmission with minimal reflectance. A study is made on the benefits
derived from smart window done on a hypothetical 8- storey building. This encompasses
a description of its quantitative impact on cooling load, energy consumption and energy
savings achieved as compared with other forms of glazing. In conclusion, it is observed
that the smart window meets the technical and economic targets set, thus making it a
viable long-term investment for high-rise commercial buildings.

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ABSTRAK
Dengan peningkatan kos tenaga seluruh dunia yang ketara, wujud satu keperluan
yang mendesak untuk mengurangkan pembakaran bahan api seterusnya mengurangkan
penggunaan tenaga. Keadaan ini, yang ditambah lagi dengan kesan pemanasan global
yang mengancam kediaman manusia, telah membuatkan negara-negara termasuk
Malaysia lebih sedar akan permasalahan ini. Projek ini membicarakan tentang tingkap
pintar, iaitu sejenis tingkap yang terdiri daripada dua lapisan kaca di mana satu keping
kaca merupakan sejenis kaca pantulan haba berprestasi tinggi dan lapisan satu lagi
sejenis kaca disaluti dengan lapisan berpancaran rendah. Kombinasi kaca ini
menghasilkan kecekapan tenaga yang optimum dan penghantaran cahaya siang yang
tinggi dengan pantulan minimum. Satu kajian dibuatkan berdasarkan kelebihan tingkap
pintar pada sebuah bangunan 8 tingkat. Ini merangkumi gambaran kesan kuantitatif ke
atas beban pendinginan, penggunaan tenaga dan penjimatan tenaga yang diperolehi
berbanding dengan penggunaan jenis kaca yang lain. Sebagai kesimpulan, pemerhatian
dibuat berdasarkan kemampuan tingkap pintar memenuhi sasaran teknikal dan ekonomi
yang menjadikannya suatu pelaburan jangka panjang yang boleh diaplikasikan pada
bangunan-bangunan komersil bertingkat tinggi.

VII
TABLE OF CONTENTS
CHAPTER TITLE PAGE
TITLE PAGE
DECLARATION
DEDICATION
ACKNOWLEDGEMENT
ABSTRACT
ABSTRAK
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
LIST OF APPENDICES
I
II
III
IV
V
VI
VII
XI
XII
XV

VIII
I PROJECT OVERVIEW 1
1.1 Introduction 1
1.2 Objective of the Project 4
1.3 Scopes of the Project 4
1.4 Methodology 5
1.5 Chapter Outline 6
II LITERATURE REVIEW 7
2.1 Introduction 7
2.2 Overview of Energy Use in Commercial Buildings 9
2.2.1 The Concept of Zones 9
2.2.2 Energy Loads in Commercial Buildings 10
2.2.3 The Effect of Windows on Heating and Cooling 11
2.2.4 The Effect of Windows on Lighting Energy Use 14
2.3 Heat Transfer Mechanisms and Glazing Properties 16
Related to Radiant Energy Transfer
2.4 Measuring Energy-related Properties 21
2.5 Smart Windows 23
2.6 The operation of Smart Windows 24

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III SOFTWARE AND SIMULATION 25
3.1 WINDOW 5.2a 25
3.1.1 Main Screen (WINDOW 5.2a Library) 26
3.1.2 Construct a WINDOW 27
3.1.3 WINDOW 5.2a Library 30
3.1.4 Result from WINDOW 5.2a 33
3.2 EQUEST V3.6 35
3.2.1 Using EQUEST V3.6 36
3.2.2 Main Screen: Schematic Design Wizard 39
3.2.3 Building footprint 41
3.2.4 Customized Building Footprint 42
3.2.5 Exterior Windows 47
3.2.6 Activity Areas Allocation 49
3.2.7 Occupied Loads by Activity Area 52
3.2.8 Main Schedule Information 53
3.2.9 Result from EQUEST V3.6 54

X
IV PLAN AND STRATEGIES 58
4.1 Case Study Building: Ang’s Building 58
4.1.1 Base building profile 58
4.1.2 Johor Bharu’s climatic conditions 61
4.1.3 Building Orientation 61
4.1.4 Load Estimation 62
4.2 Simulation Result 63
4.2.1 Annual Energy Cost Saving 65
4.2.2 Investment Cost and Payback Period 67
V CONCLUSION AND RECOMMENDATION 72
5.1 Conclusion 72
5.2 Recommendation and Future work 74
REFERENCES 76
APPENDICES 78

XI
LIST OF TABLE
FIGURE NO. TITLE PAGE
3.1 Glazing properties 30
3.2 The input fields for the layers in the glazing 32
3.3 Comparison between selected glazing 34
3.4 The value of SC, VT, U-value 34
4.1 Annual Energy Cost Saving 65
4.2 Cost of construction 67
4.3 Payback Period Calculation 69

XII
LIST OF FIGURES
FIGURE NO. TITLE PAGE
2.1 Windows 8
2.2 Heat gain 12
2.3 Heat loses 12
2.4 Annual energy use comparison for nine windows types 13
2.5 Types of glazing 13
2.6 Annual energy use and peak demand 15
2.7 Ideal spectral transmittance for glazing in different climates 17
2.8 Cross section for Smart Windows 23
2.9 Smart Windows with double hung operating frame 23
2.10 Solar radiation and visible light 24
2.11 Double glazing 24
3.1 Main Screen (Window Library, Detail View) 27
3.2 Select a Glazing System for the window 28
3.3 Select a frame for the window 29

XIII
3.4 Calculate the whole product 30
3.5 Glazing System Library, Detail View 31
3.6 List of Gas in the gas library 33
3.7 General information 39
3.8 Building footprint 41
3.9 Customized Building Footprint 44
3.10 Custom Footprint Initialization Options 44
3.11 Custom Building Footprint 45
3.12 Exterior Windows 47
3.13 Custom Window / Door replacement view test 49
3.14 Activity Areas Allocation 50
3.15 Occupied Loads by Activity Area 52
3.16 Main schedule information 53
3.17 Monthly electrical consumption with Smart Windows 55
3.18 Monthly electrical consumption without Smart Windows 55
3.19 Comparison Monthly electrical consumption 56
3.20 Comparison Annually electrical consumption 56
3.21 Monthly utility bills 57
3.22 3-D view of EQUEST model for Ang’s Building 57
4.1 Ang’s building location 59
4.2 Ang’s building (Front view) 59

XIV
4.3 Ang’s building (side view) 59
4.4 Top view of Ang’s building (foot print) 60
4.5 Electric Consumption (kWh) 63
4.6 Annual Energy Consumption by Enduse 64

XV
LIST OF APPENDICES
APPENDIX TITLE PAGE
A Daily Consumption (RM) for Ang’s Building 78
B Site and Location plan 79
C 1 st to 5 th typical floor plan 80
D 6th floor plan 81

“I hereby declare that I have read this thesis and in my opinion this
Thesis in sufficient in terms of scope and quality for the award of the
Degree of Bachelor of Electrical Engineering”
Signature
: ……………………………….
Name of Supervisor : Associate Professor FARIDAH
BT MOHD TAHA
Date : 13 MAY 2008

CHAPTER 1
PROJECT OVERVIEW
1.1 Introduction
The present era is one in which energy costs have escalated in real terms and are
likely to continue to do so for the foreseeable future. According to the 1996 edition of
the World Energy Outlook, oil prices are expected to rise from US$17 per barrel in year
2000 to US$25 by year 2005. Imported gas prices and liquefied natural gas (LNG) prices
in the Asia-Pacific region are assumed to rise roughly in line with the oil price. The
current economic growth of Asia has also seen a sharp increase in demand for
electricity, as the latter is directly proportional to the former. As in the recent study by
the International Energy Agency, Asia Electricity Study, 1997, per capita incomes of
developing and newly industrialised countries grew at an average rate of 4.4% between
1970 and 1990, compared with only, 1% in Latin America and close to zero in Africa. In
1997, 11 Asian countries ranked among the 45 most competitive countries and
economies in the world.
Accordingly, electricity generation is expected to increase at average annual rates
of 6.5% from 1993 to 2000 and 5.3% from 2000 to 2010. Total electric power

2
generation in the Asia region is expected to increase from 1683.9 terawatt hours (TW h)
in 1993 to 2960.8 TW h in 2000 and 5542.8 TW h in 2010. These rates are much higher
than the global averages, which are expected to be 2.4% and 3.1% in the respective
periods.
A rapid growth of energy consumption in the Association of South East Asian
Nations (ASEAN) has been observed during the past three decades. During the period
1970 to 1987, commercial energy consumption grew from 27 to 85 million tons of oil
equivalent (Mtoe) and has continued to grow. Electricity consumption has increased
from 20 to 101 billion kilowatt hours (kWh). In this context, the growth of electricity
consumption in buildings has been very rapid throughout the ASEAN region. In 1970,
residential buildings consumed approximately 3.5 billion kWh and commercial
buildings, 4.3 billion kWh. By 1987, residential buildings in ASEAN consumed 22
billion kWh and commercial buildings, 23 billion kWh. The total annual cost of
electricity for buildings in ASEAN (45 billion kWh) is about US$4 billion and because
electricity consumption has grown rapidly in buildings and continues to grow, electricity
costs in the sector are likely to increase markedly over time. Investigations have
revealed a considerable potential for cost-effective conservation in commercial buildings
throughout ASEAN.
In Malaysia, the demand for electricity over the past 10 years has been increasing
at an annual rate of about 8%. The commercial buildings in Malaysia consumed 420 GW
h of electricity in 1992. This represented an increase of 11.4% over the electricity
consumption in 1991. Comparative studies involving commercial building perimeter
zone electric energy and peak electric demand as a function of window glazing type in
hot and humid climates have been attempted, the analysis of which have indicated the
potential for substantial savings through combined solar load control and use of day
lighting.

3
As a result, building services engineers, chief architects, estate managers, i.e., all
those charged with the task of reducing energy costs in buildings under their care, are
having to exercise considerable technical skill and judgment in identifying those
efficiency improvement measures that are appropriate to their particular circumstances.
They also need to ensure that those measures selected are properly implemented and
utilised. There are now many ways to improve the energy efficiency of existing or new
buildings, some involving the way buildings are run, others requiring capital investment
in various possible retrofit measures. Many of these improvement measures involve
familiar recognizable techniques such as higher efficiency plant, Building Automated
Systems (BAS), and special type of glazing which is the main focus in this project.
As we move into the 21st Century, the buzzword used among developers and
building professionals would be intelligent buildings. An intelligent building is one that
creates an environment that maximizes the efficiency of the occupants of the building
while at the same time allowing effective management of resources with minimum
lifetime costs. In a nutshell, intelligent buildings are buildings that possess state-of-theart
technology with the main objective of serving its users better and at the same time
saving energy.
Based on magazines and journals, new inventions and products are being
introduced almost daily worldwide. For example, uninterruptible power supplies (UPS)
designed to provide optimum protection and continuous power to key equipment like
local network servers, Internet and Intranet systems, computers, PABX systems and
industrial equipment, lifts capable of moving people horizontally and vertically and
variable refrigerant volume (VRV) air-conditioning systems that has precise temperature
control to eliminate overcooling or under cooling, etc. Hence, we can see that intelligent
buildings would be the next generation of buildings in society. The purpose of this paper
is to study the effectiveness of combining a reflective coating and low emissivity (low-e)
coating glass commonly known as 'smart windows' to cut down heat entering the
building in view of intelligent buildings, energy and cost savings.

4
1.2 Objective of The project
The main core of this project is to study the potential and effectiveness of Smart
Windows for application in Malaysia. This new technology will make us use energy
efficiently by reducing the energy consumptions. Other than that, is to analyze the
compatible aspect that should be considered such as the suitability of weather,
environment and location for commercial purposes. Besides, the purpose of this project
is to identify the cost of construction of Smart Windows and its saving potential.
1.3 Scopes of The Project
There are several scope had been outlined. The scope of this project includes
study on the theory and operation of Smart Windows, exploring the benefits of Smart
Windows, do the research on the feasibility of the Smart Windows towards weather,
places and environment.
The project also analyzes potential and the effectiveness of Smart Windows.
Appropriate energy saving measurement was identified and calculation on the annual
energy cost saving, the total cost of construction and also a payback period of this new
technology performed.

5
1.4 Methodology
In order to achieve the objective stated, there must be a good
methodology that should be applied. There are 4 methods that are used to
complete this project. First, all information and theory about Smart Windows
such as its benefit, future potential, how it works, characteristics and etc are
collected. The information is so important in designing and simulation process.
Secondly, the real data about case study building is obtained. In this
project, Ang’s building at Taman Tasek, Johor Bharu is chosen as my case study
building. From them, the real information and data such as building plan,
window’s material, schedule of lighting and occupants, building orientation,
location and etc are obtained.
Thirdly, designing and simulation process. In this project, two software
which are EQUEST 3.6 and WINDOW 5.2a is used. Window 5.2a is used to
design and determine the thermal and solar properties of glazing and window
systems. After designing the Smart Windows, EQUEST 3.6 is used to do
simulation in order to determine the energy consumption and cooling load
required by the building.
Lastly, calculation on the total energy cost saving for Ang’s building to
make comparison between before and after the implementation of Smart
Windows. Cost of construction and long-term investment measurement in
purpose to commercialize them are also calculated.

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1.5 Chapter Outline
This thesis has 5 chapters. Brief description of each chapter is as follows:
Chapter 1: Explains about introduction to the current issues that make Smart
Windows will become so important in the future. Besides that, this chapter describe
about objective, scope and methodology of project.
Chapter 2: Focus on the literature review and theory about Smart Windows. It
discusses about what is Smart Windows How it works The importance of windows, its
benefit and potential, glazing type and etc.
Chapter 3: This chapter is known as Design and simulation chapter. In this
chapter, designing process by using selected software (EQUEST 3.6 and Window 5.2a)
is presented. The detail of these two software will be explained. The simulation process
also will be shown in this chapter.
Chapter 4: Explaining about research at the Ang’s building. This chapter will
show us how much energy and cost can be saved after the implementation of Smart
Windows.
Chapter 5: For this closing chapter, discussion and conclusions will be presented.
Some recommendation also will be stated in this chapter.

CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Windows are one of the most significant elements in the design of any building.
Whether there are relatively small punched openings in the facade or a completely
glazed curtain wall, windows is usually a dominant feature of the building's exterior
appearance. Windows can appear highly reflective, darkly opaque, or transparent,
revealing or hiding activity within the building. Their color, transparency, and reflected
patterns can change with the time of day and weather.

8
Figure 2.1: Windows
Although exterior appearance is important in architectural design, the traditional
purpose of windows is to provide light, view, and fresh air for the occupants. As
completely sealed, mechanically ventilated, and electrically-lit commercial buildings
became the norm in the last half of the 20th century, the importance of windows in
meeting the needs of occupants was diminished. There is a growing recognition,
however, that even though light and air can be provided by other means, the benefits of
windows are highly valued and contributes to the satisfaction, health, and productivity of
building occupants. In addition to the trend toward more human-centered design, there is
an urgent need for significant improvements in building energy performance in the
immediate future.
The challenge in designing facades and selecting windows in commercial
buildings is balancing many issues and criteria. Technical issues such as structure,
moisture control, acoustics, and security require complex tradeoffs cost is always a
concern. Increasingly, costs are being viewed in a life cycle context that accounts for the
impact of a window on long term operational, maintenance, and replacement costs as
well as the initial expense. A critical concept that weaves together all of these concerns
is high performance design, also referred to as sustainable design or green design.
Generally, high performance design is intended to produce buildings that are energy

9
efficient, healthy, and economical in the long run, and use resources wisely to minimize
the impact on the environment. An important concept to achieve these goals is integrated
design that regards the entire building and its occupants as an interactive system.
Fenestration design and glass selection is the point in the design process with the
greatest direct effect on the building’s future energy performance, and the point where
an intricate set of aesthetics and performance issues come together. Efforts have been
directed at exploring the behavior of a building affected with solar radiation through
fenestration. As such, the role of glass in modern building is very significant. Window
area, frame type, and the choice of glazing technologies are the common factors used to
determine acceptable window energy performance. Windows are usually designed in a
colour that complements the building design; with a shading coefficient (SC) low
enough for reasonable heat gain reduction. Recent and new technologies may change the
measure of acceptability and add to the set of intricate issues that already make windows
one of the most important parts of architectural design. Besides looking at the thermal
effect of windows in office building energy economics, emphasis must also be placed on
their lighting value with the same scrutiny.
2.2 Overview of Energy Use in Commercial Buildings
2.2.1 The Concept of Zones
All commercial buildings are divided into zones which represent areas of the
building served by discreet portions of the heating, cooling and ventilating system.
There are also lighting control zones which may not correspond to mechanical system
zone. In a sense, a mechanical system zone operates like a separate building, receiving

10
heating, cooling, and ventilation from either its own packaged unit or a central system as
needed.
The reason for dividing a building into zones is that different spaces have
different requirements and require separate control. For example, a highly-ventilated
auditorium and a storage room with almost no ventilation would require separate zones.
Separate zones are also needed for a north-facing space which may require heat in
winter at the same time a south-facing space requires none because it is heated by the
sun. Similarly, an interior zone with no windows may require cooling at the same time a
perimeter zone with windows requires heating.
Some buildings like a school with long narrow wings of classrooms may have
mostly perimeter zones, while others like a massive office block may only have a small
percentage of spaces on the perimeter. The use of a court or atrium in the center of a
building creates interior perimeter zones that have some of the characteristics of both. If
the atrium is large and well day lighted, these interior perimeter zones can behave like
exterior perimeter zones with respect to light and view. If the atrium is fully conditioned
however, there may be no heat loss or gain or air movement as there would be through
an exterior wall. On the other hand, an atrium may be unconditioned or a semiconditioned
buffer space that behaves more like the outdoors with moderate temperature
fluctuations and perhaps fresh air available.
2.2.2 Energy Loads in Commercial Buildings
Lighting, heating, cooling, fans, pumps, and any equipment or furnishings
plugged into electrical circuits are the main uses of energy in commercial buildings.
Electric lights, machines (i.e. computers, copiers, etc.), and people generate heat referred

11
to as internal loads or internal heat gain. In an internal zone of the building there may be
no other loads besides electric lighting, plug loads, and internal gains. Usually, these
zones require cooling even in colder climates. Since ventilation with fresh air is also
required in spaces with people, the outside air must be heated and cooled as well.
Depending on the climate, during certain periods the outside air is the right temperature
to provide cooling in an overheated space.
In a perimeter zone, heat losses and gains due to transmission through the
building envelope (roof and walls) are also part of the heating and cooling loads. If a
window or skylight is present, these losses and gains can be even more significant.
Besides having relatively high rates of heat transmission, windows permit solar radiation
to enter directly, resulting in major heat gain potential.
In some commercial buildings, the internal heat gains are greater than losses and
gains through the envelope. This is referred to as an internal load-dominated building.
This will naturally occur in massive buildings with a high ratio of interior to perimeter
zones. When the losses and gains through the building envelope outweigh the internal
gains, it is referred to as a climate-dominated or skin-dominated building.
2.2.3 The Effect of Windows on Heating and Cooling
At the scale of the perimeter zone, the role the window can be significant.
Windows are the modulator of heat, light and air. The overall energy use patterns of the
internal zones do not directly affect window design and selection. Windows have an
important influence on the energy use and people in the perimeter zone, even if it is a
small percentage of the total building floor area. If enclosed rooms such as private

12
Figure 2.2: Heat gain
Figure 2.3: Heat loses
offices are on the building perimeter, then these automatically define the perimeter zone
by their dimension, usually 10 to 20 feet. In larger spaces, such as an open office area,
the depth of the perimeter zone can vary. The heating and cooling effects may only
influence the first 10 feet near the windows, but the daylight may penetrate up to 25 feet
or more if properly designed. The desire of occupants for daylight, view, and fresh air is
leading to buildings that are thinner in profile with more perimeters and less interior
zones.
As shown in Figures 2-3 and 2-4, a typical perimeter office has either heat gains
or heat losses through the roof, walls, and windows. The impact of window choice on
annual energy use is illustrated in Figure 2-5 for a 15-foot-deep south-facing perimeter
zone in Chicago. Heating energy use diminishes considerably in Chicago as the window
U-factor improves from 1.25 (Window A-clear single glazing) to 0.14 (Window I-
quadruple glazed units). High performance windows also reduce cooling energy use. In
Chicago, lower electric use for cooling corresponds to windows with lower SHGC (both
lighting and other equipment use the same amount electricity in all cases). Although the
effect is not show here, operating windows may reduce mechanical cooling costs by
providing natural ventilation during certain periods of the year.

13
Figure 2.4: Annual energy use comparison for nine windows types
Figure 2.5 : Types of glazing

14
2.2.4 The Effect of Windows on Lighting Energy Use
In addition to transmitting heat gains and losses, windows and skylights also
transmit light. Typically, this natural light is a desirable amenity but the electric lights
continue to burn resulting in no energy savings. In recent years, methods and
technologies to use this daylight to reduce electric lighting have emerged. Daylight is
brought into the building by sidelighting with windows or toplighting with skylights,
light monitors, or clerestory windows. The examples throughout this book focus on
sidelighting but the general concepts and performance issues apply to toplighting as
well.
The first requirement for an integrated daylight/electric light system is that lights
are controlled in a way that allows for the energy reduction to occur. For example, lights
near windows must be switched off separately from the rest. In addition, individual
fluorescent tubes within light fixtures may be switched separately allowing for a range
of light levels instead of only 100 percent on or off. Dimmable light fixtures also permit
electric light levels to be reduced. To take advantage of the natural light from a window,
either people or automatic controls must switch off the electric lights. Occupant
switching can be effective but requires active participation and usually will not be done
optimally to reduce energy use. If the daylighting is plentiful and uniformly distributed,
there is a greater chance that people will switch off the lights. Portions of the electric
lighting can also be switched off or dimmed automatically in response to a photosensor.
This type of system is designed to operate optimally without depending on occupant
participation. However, these systems are more expensive than simple switching and
represent emerging technology where their installation and operation must be carefully
monitored to ensure the projected savings.
Figure 2.6 illustrates the impact of using a daylight control system in a southfacing
perimeter zone in Chicago. Compared to the cases where there are no daylight

15
controls, considerable reductions in electric lighting energy occur for most window
types (except Window D which has a very low VT).
Figure 2.6 : Annual energy use and peak demand comparison by lighting system
It can also be noted that without as much heat gain from the electric lights,
cooling energy use is slightly smaller and heating energy use slightly greater in many
cases. The perimeter zone used in these examples is a 10-foot-wide by 15-foot-deep
enclosed office with a 9-foot-high ceiling. A 6 x 6 window (36 square feet) is located on
the exterior wall.
There are no special techniques such as light shelves used to project daylight
deeper and more evenly into the space. While all the electrical energy use comparisons
in Figure 2.6 show significant savings by using lighting controls, they assume conditions
with reliable dimmable ballasts controlled by daylight sensors. In reality, there can be a
range of performance depending on the design and operation of the system. Even if
today's dimmable ballasts and light sensors may not provide optimal performance or be
cost effective, they are likely to be in the future. Since the window system has a
relatively long life, it should be designed based on the assumption that daylight control
systems will be installed in the future. This interaction between the building envelope
and lighting system is one of the key synergistic opportunities in developing high-

16
performance buildings. The design and selection of windows is a pivotal aspect of this
integrated design approach.
2.3 Heat Transfer Mechanisms and Glazing Properties Related to Radiant
Energy Transfer
Most window assemblies consist of glazing and frame components. Glazing may
be a single layer of glass (or plastic) or multiple layers with air spaces in between. These
multiple layer units, referred to as insulated glazing units (IGU), include spacers around
the edge and sometimes lower conductance gases in the spaces between glazings.
Coatings and tints affect the performance of the glazing. The IGU then is placed within a
frame of aluminum, steel, wood, plastic, or some hybrid or composite material. Some
advanced curtain wall systems do not have frames in the conventional sense.
Heat flows through a window assembly in three ways: conduction, convection,
and radiation. Conduction is heat traveling through a solid material, the way a frying pan
warms up. Convection is the transfer of heat by the movement of gases or liquids, like
warm air rising from a candle flame. Radiation is the movement of heat energy through
space without relying on conduction through the air or by movement of the air, the way
you feel the heat of a fire.
Conduction through glass and solid frame materials and convection within air
spaces are discussed in the section on insulating value (U-factor). Heat transfer through
radiation deserves special attention because it has been the source of much recent
innovation in window energy performance. Three things happen to solar radiation as it
passes through a glazing material. Some is transmitted, some is reflected, and the rest is
absorbed. Figure 2.7 shows the solar and thermal parts of the electromagnetic spectrum

17
that relate to windows. These include the ultraviolet, visible, near-infrared, and farinfrared
ranges.
Glazing types vary in their transparency to different parts of the visible spectrum.
For example, a glass that appears to be tinted green as you look through it toward the
outside will transmit more sunlight from the green portion of the visible spectrum, and
absorb/reflect more of the other colors. Similarly, a bronze-tinted glass will
absorb/reflect the blues and greens and transmit the warmer colors. Neutral gray tints
absorb/reflect most colors equally.
Figure 2.7: Ideal spectral transmittance for glazing in different climates
This same principle applies outside the visible spectrum. Most glass is partially
transparent to at least some ultraviolet radiation, while plastics are commonly more
opaque to ultraviolet. Glass is opaque to far-infrared radiation but generally transparent
to near-infrared. Strategic utilization of these variations has made for some very useful
glazing products. The four basic properties of glazing that affect radiant energy transfer
which are transmittance, reflectance, absorptance, and emittance are described below.

18
i )
Transmittance
Transmittance refers to the percentage of radiation that can pass through glazing.
Transmittance can be defined for different types of light or energy, e.g., visible
transmittance, UV transmittance, or total solar energy transmittance. Transmission of
visible light determines the effectiveness of a type of glass in providing daylight and a
clear view through the window. For example, tinted glass has a lower visible
transmittance than clear glass. While the human eye is sensitive to light at wavelengths
from about 0.4 to 0.7 micrometers, its peak sensitivity is at 0.55, with lower sensitivity
at the red and blue ends of the spectrum. This is referred to as the photopic sensitivity of
the eye.
More than half of the sun's energy is invisible to the eye and reaches us as either
ultraviolet (UV) or, predominantly, as near-infrared. Thus, total solar energy
transmittance describes how the glazing responds to a much broader part of the spectrum
and is more useful in characterizing the quantity of solar energy transmitted by the
glazing.
With the recent advances in glazing technology, manufacturers can control how
glazing materials behave in these different areas of the spectrum. The basic properties of
the substrate material (glass or plastic) can be altered, and coatings can be added to the
surfaces of the substrates. For example, a window optimized for daylighting and for
reducing heat gains should transmit an adequate amount of light in the visible portion of
the spectrum, while excluding unnecessary heat gain from the near-infrared part of the
electromagnetic spectrum.
On the other hand, a window optimized for collecting solar heat gain in winter
should transmit the maximum amount of visible light as well as the heat from the nearinfrared
wavelengths in the solar spectrum, while blocking the lower-energy radiant heat
in the far-infrared range that is an important heat loss component. These are the
strategies of various types of low-emittance coatings.

19
ii )
Reflectance
Just as some light reflects off of the surface of water, some light will always be
reflected at every glass surface. A specula reflection from a smooth glass surface is a
mirror like reflection similar to when you see an image of yourself in a store window.
The natural reflectivity of glass is dependent on the quality of the glass surface, the
presence of coatings, and the angle of incidence of the light. Today, virtually all glass
manufactured in the United States is float glass and has a very similar quality with
respect to reflectance. The sharper the angle at which the light strikes, however, the
more the light is reflected rather than transmitted or absorbed. Even clear glass reflects
50 percent or more of the sunlight striking it at incident angles greater than about 70
degrees. (The incident angle is formed with respect to a line perpendicular to the glass
surface.)
The reflectivity of various glass types becomes especially apparent during low
light conditions. The surface on the brighter side acts like a mirror because the amount
of light passing through the window from the darker side is less than the amount of light
being reflected from the lighter side. This effect can be noticed from the outside during
the day and from the inside during the night. For special applications when these surface
reflections are undesirable (i.e., viewing merchandise through a store window on a
bright day), special coatings can virtually eliminate this reflective effect.
Most common coatings reflect in all regions of the spectrum. However, in the
past twenty years, researchers have learned a great deal about the design of coatings that
can be applied to glass and plastic to reflect only selected wavelengths of radiant energy.
Varying the reflectance of far-infrared and near-infrared energy has formed the basis for
high-solar-gain low-E coatings for cold climates, and for low-solar-gain low-E coatings
for hot climates.

20
iii )
Absorptance
Energy that is not transmitted through the glass or reflected off of its surfaces is
absorbed. Once glass has absorbed any radiant energy, the energy is transformed into
heat, raising the temperature of the glass.
Typical 1/8-inch (3 mm) clear glass absorbs only about 8 percent of sunlight at a
normal angle of incidence. The absorptance of glass is increased by glass additives that
absorb solar energy. If they absorb visible light, the glass appears dark. If they absorb
ultraviolet radiation or near-infrared, there will be little or no change in visual
appearance. Clear glass absorbs very little visible light, while dark tinted glass absorbs a
considerable amount. The absorbed energy is converted into heat, warming the glass.
Thus, when these "heat-absorbing" glasses are in the sun, they feel much hotter to the
touch than clear glass. They are generally gray, bronze, or blue-green and are used
primarily to lower the solar heat gain coefficient and to control glare. Since they block
some of the sun's energy, they reduce the cooling load placed on the building and its airconditioning
equipment. Absorption is not the most efficient way to reduce cooling
loads.
All glass and most plastics, however, are generally very absorptive of farinfrared
energy. This property led to the use of clear glass for greenhouses, where it
allowed the transmission of intense solar energy but blocked the retransmission of the
low-temperature heat energy generated inside the greenhouse and radiated back to the
glass.
iv)
Emittance
When heat or light energy is absorbed by glass, it is either convicted away by
moving air or reradiated by the glass surface. This ability of a material to radiate energy
is called its emissivity. Windows, along with all other objects, typically emit, or radiate,

21
heat in the form of long-wave far-infrared energy. This emission of radiant heat is one of
the important heat transfer pathways for a window. Thus, reducing the window's
emission of heat can greatly improve its insulating properties.
Standard clear glass has an emittance of 0.84 over the long wavelength portion of
the spectrum, meaning that it emits 84 percent of the energy possible for an object at its
temperature. It also means that for long-wave radiation striking the surface of the glass,
84 percent is absorbed and only 16 percent is reflected. By comparison, low-E glass
coatings have an emittance as low as 0.04.
2.4 Measuring Energy-related Properties
There are four energy performance characteristics of windows used to portray
how energy is transferred and are the basis for how energy performance is quantified.
They are:
• U-factor: The U-factor (also referred to as U-value) is the standard way to
quantify insulating value. It indicates the rate of heat flow through the window.
The U-factor is the total heat transfer coefficient of the window system (in
Btu/hr-sq ft-°F or W/sq m-°C), which includes conductive, convective, and
radioactive heat transfer. It therefore represents the heat flow per hour (in Btus
per hour or Watts) through each square foot (or square meter) of window for a
1°F (1°C) temperature difference between the indoor and outdoor air
temperature. The R-value is the reciprocal of the total U-factor (R=1/U). As
opposed to an R-value, the smaller the U-factor of a material, the lower the rate
of heat flows.

22
• Solar Heat Gain Coefficient: Window standards are now moving away from
use of shading coefficient to solar heat gain coefficient (SHGC), which is defined
as that fraction of incident solar radiation that actually enters a building through
the window assembly as heat gain. The SHGC is influenced by all the same
factors as the SC, but since it can be applied to the entire window assembly, the
SHGC is also affected by shading from the frame as well as the ratio of glazing
and frame. The solar heat gain coefficient is expressed as a dimensionless
number from 0 to 1. A high coefficient signifies high heat gain, while a low
coefficient means low heat gain.
• Visible Transmittance: Visible transmittance (VT) also referred to as visible
light transmittance (VLT), is the amount of light in the visible portion of the
spectrum that passes through a glazing material. A higher VT means there is
more daylight in a space which, if designed properly, can offset electric lighting
and cooling loads due to lighting.
• Shading Coefficient: The shading coefficient (SC) is only defined for the
glazing portion of the window and does not include frame effects. It represents
the ratio of solar heat gain through the system relative to that through 1/8-inch (3
mm) clear glass at normal incidence. The shading coefficient is expressed as a
dimensionless number from 0 to 1. A high shading coefficient means high solar
gain, while a low shading coefficient means low solar gain. For any glazing, the
SHGC is always lower than the SC. To perform an approximate conversion from
SC to SHGC, multiplying the SC value by 0.87.

23
2.5 Smart window
When reflective glass and low-e are combined together, a high thermal-insulation
double layer glass is produced. The two glasses are kept at a fixed interval by a spacer
containing a strong absorbent to ensure that the air layer is kept dry, and the surrounding
edges are sealed with special elastic glue. Hence, the benefits derived from highperformance
heat reflective glass and low-e glass are combined together to achieve an
ultimate high-performance glazing commonly known as smart window.
Figure 2.8 : Cross section for Smart Windows
Figure 2.9: Smart Windows with double hung
operating frame

24
2.6 The operation of Smart Windows
Visible light and solar heat radiation will be reflected, transmitted or absorbed
when they are passes through any glazing material (as shown in figure 2.10). A normal
glazing like nowadays does not have the ability to control how much solar heat radiation
or visible light will transmitted or reflected. Traditional solution to reduce solar heat
gain such as tinted glazing means the amount of light is reduced as well. So, with Smart
Windows, it can provide better solar heat gain reduction with minimal lost of visible
light.
In order to understand the operation of Smart Windows, let’s look into the
sample of glazing as shown in Figure 2.11. From this figure B, its SHGC value is 0.27
and VT value is 0.60. It means that only 27% of solar heat gain will be transmitted and
the rest will be reflected and absorbed. Same as VT value, only 60% from visible light
will be transmitted. This shows how they are operate based on their own glazing
properties (VT and SHGC).
Figure 2.10 : solar radiation and visible
light through glazing
material is either
reflected
transmitted or absorbed
Figure 2.11 : Double glazing

CHAPTER 3
SOFTWARE AND SIMULATION
3.1 WINDOW 5.2a
WINDOW 5.2a is a state-of-the-art, Microsoft Windows TM-based computer
program developed at Lawrence Berkeley National Laboratory (LBNL) for use by
manufacturers, engineers, educators, students, architects, and others. It used to determine
the thermal and solar optical properties of glazing and window systems. WINDOW 5.2a,
is a significant update to LBNL's WINDOW 4.1 computer program and includes all of
the WINDOW 4.1 capabilities as well as a state of the art MS-Window as interface,
updated algorithms consistent with ASHRAE SPC142 and ISO15099, a Condensation
Resistance Index in accordance with a draft version of NFRC 500, a surface temperature
map, an integrated database of properties and links to other LBNL Window analysis
software such as THERM 5, RESFEN and Optics5.

26
3.1.1 Main Screen (WINDOW 5.2a Library)
The WINDOW 5.2a main screen (which is the "detail screen" of the WINDOW
5.2a Library) for defining a complete WINDOW 5.2a product, shown below, has 4 main
screen areas:
• Left hand column for buttons (such as Calc, List, Details) and other common
tools.
• Input values such as Name, Size, etc.
• Graphic representation of the WINDOW 5.2a. This representation has the
various elements (glazing systems, frames, and dividers) which can be
selected for a particular WINDOW by clicking on the element (this is shown
in the following figures).
• Results and feedback about currently selected WINDOW 5.2a or WINDOW
5.2a component.

27
Graphic representation of
window
Result
Feedback about selected glazing
Figure 3.1: Main Screen (Window Library, Detail View).
3.1.2 Construct a WINDOW
Select the Glazing System for the WINDOW: To view the characteristics of
the glazing system of the WINDOW, click on the glazing system component and the
information is displayed in the lower right group Glazing System Library box, as shown
below. This information is from the Glazing System Library.
To select a new glazing system for this WINDOW, click on the glazing system to
be changed, and either use the pull down list to see the names of all the records in the

28
Glazing System Library, or click on the double arrow button, and another WINDOW
will open which displays all the values from the Glazing System Library.
Figure 3.2: Select a Glazing System for the window
Select the frame for the WINDOW: To view the characteristics of the frame of
the WINDOW 5.2a, click on a frame component and the information is displayed in the
lower right group box, as shown below. This information is from the Frame Library. To
select a new frame for this WINDOW, click on the frame component to be changed, and
either use the pull down list to see the names of all the frames in the Frame Library, or
click on the double arrow button, and another WINDOW will open which displays all
the values from the Frame Library.

29
Figure 3.3: Select a frame for the window
Calculation: WINDOW 5.2a will calculate the total product properties for the
current record when the Calc (F9) button is clicked.

30
Figure 3.4: Calculate the whole product
properties.
Results: WINDOW 5.2a calculates the following values for the Total WINDOW
Results:
U-value Total Product U-value
SHGC Solar Heat Gain Coefficient.
VT Visible Transmittance
CI Condensation Index, calculated according to NFRC 500
Procedures (Draft). It is possible to see the intermediate
values used for the CI calculation by pressing
the Detail button, explained in detail in Chapter 4 of this
manual.
Table 3.1: Glazing properties
3.1.3 WINDOW 5.2a Library
The WINDOW 5.2a Library is where the whole product is constructed from each
of the components (frames, glazing systems, dividers, environmental conditions). The
calculation results will be for the entire product.

31
Glazing System Library: The Glazing System Library is used to construct
glazing systems to determine the center of glass U-factor, which can be used in the
WINDOW 5.2a library to construct a whole product. Glazing Systems consist of glass
layers selected from the Glass Library (which are from the Optics5 database) and
definitions of the gaps between the glass layers, which are defined by a thickness and
selections from the Gas Library. When the glass layers and gaps have been defined, the
results are calculated using the Calc button.
Figure 3.5: Glazing System Library, Detail View.
properties.

32
ID
The unique ID associated with each glazing system record.
Name The name of the glass layer. If the record was imported from the
Optics5 database, this name will automatically come from that
database.
#Layers The number of layers for the up and down arrows to the right of
this field. The program will automatically adjust the number of
layers in the layers detail section of the screen based on this
number
Tilt The tilt of the glazing system. Default: 90 o
Environment The name of the appropriate environmental condition from the
Conditions Environmental Condition Library, selected using the arrow to
the right of the field. Default: ASHRAE/NFRC.
Comment A user entered comment.
Overall The overall thickness of the glazing system. Units: mm (SI);
Thickness inches (IP).
The following section describes the input fields for the layers in the glazing
system.
ID
The unique ID associated with each glazing system record.
Name The name of the glass layer. If the record was imported from the
Optics5 database, this name will automatically come from that
database.
Mode An identifier to determine the glass layer approval status. At this
time, the only approval mode implemented is NFRC, indicated
by “#”, and only records with “#” in this field can be used for
NFRC simulations.
Thick Thickness Glass thickness. Units: mm (SI); inches (IP).
Flip A checkbox to indicate whether or not the glass layer is flipped.
Click the box to put an ‘x’ in it, which indicates that the layer is
flipped. This will cause the values for emissivity on the 1 and 2
surfaces to be interchanged.
Tsol Solar transmittance of the glazing layer.
Rsol1 Solar reflectance of the glazing layer, exterior-facing side.
Rsol2 Solar reflectance of the glazing layer, interior-facing side.
Tvis
Rvis1
Rvis2
Tir
E1
E2
Cond
Visible transmittance of the glazing layer.
Visible reflectance of the glazing layer, exterior-facing side.
Visible reflectance of the glazing layer, interior-facing side.
Thermal infrared (longwave) transmittance of the glazing layer.
Infrared (longwave) emittance of the glazing layer, exteriorfacing
side
Infrared (longwave) emittance of the glazing layer, interiorfacing
side
Conductance of glass. Units: W/m-K (SI); Btu/h-ft-oF (IP)
Table 3.2: The input fields for the layers in the glazing
system.

33
Gas Library: The List View shows all the records in the Gas Library.
Figure 3.6 : List of Gas in the gas library
3.1.4 Result from WINDOW 5.2a
To make sure that the chosen glazing for Smart Windows is the best performance
among others glazing, a comparison will be made. The result for the comparison as
shown in Table 3.3. The glazing that has the smaller value of SC is the best one.

34
SIMULATION
RUN
1
2
3
4
5
6
7
8
9
10
GLASS TYPE GLASS COLOUR SC
24 mm double glaze
float glass
24 mm double glaze
float glass
24 mm double glaze
float glass
24 mm double glaze
float glass heat
reflecting glass
24 mm double glaze
float glass heat
reflecting glass
24 mm double glaze
float glass heat
reflecting glass
24 mm double glaze
float glass heat
reflecting + low-e glass
24 mm double glaze
float glass heat
reflecting + low-e glass
24 mm double glaze
float glass heat
reflecting + low-e glass
24 mm double glaze
float glass heat
reflecting + low-e glass
(Smart Windows)
6 mm clear + 12 mm air
space + 6 mm clear
6 mm green + 12 mm air
space + 6 mm clear
6 mm azurlite + 12 mm
air space + 6 mm clear
6 mm clear + 12 mm air
space + 6 mm clear
6 mm green + 12 mm air
space + 6 mm clear
6 mm azurlite + 12 mm
air space + 6 mm clear
6 mm clear + 12 mm air
space + 6 mm clear
6 mm green + 12 mm air
space + 6 mm clear
6 mm azurlite + 12 mm
Krypton space + 6 mm
clear
6 mm azurlite + 12 mm
Argon space + 6 mm
clear
0.82
0.58
0.55
0.43
0.33
0.24
0.35
0.26
0.19
0.18
Table 3.3: Comparison between selected glazing
From the simulation by using WINDOW 5.2a, here is the details result between
normal glazing and glazing for Smart windows:
Glazing properties Smart Windows Normal
SC 0.18 0.80
VT 0.17 0.81
U-value (W/m 2 .k) 0.65 4.823
3.2 Table 3.4: EQUEST The value V3.6 of SC, VT, U-value for normal glazing and smart windows glazing

35
3.2 EQUEST V3.6
QUEST’s engine is “DOE-2.2”, an advanced derivation of DOE-2, initially
developed jointly by Lawrence Berkeley National Laboratory and J.J. Hirsch and
Associates, under funding from the U.S. Department of Energy and the Electric Power
Research Institute. On-going development of DOE-2-based tools, like EQUEST, is
continuing under both public and industry funding. The principal focus of these ongoing
efforts has been to make detailed hour-by-hour simulation more reliable and affordable
for a broader base of design and buildings professionals.
EQUEST allows us to perform detailed analysis of today’s state-of-the-art
building design technologies using today’s most sophisticated building energy use
simulation techniques but without requiring extensive experience in the "art" of building
performance modeling. This is accomplished by combining a building creation wizard,
an energy efficiency measure (EEM) wizard, and a graphical results display module with
a simulation "engine" derived from an advanced version of the DOE-2 building energy
use simulation program.
EQUEST helps to overcome past barriers to simulation by incorporating two
building creation wizards: the Schematic Design Wizard (the “Schematic Wizard”) and
the Design Development Wizard (the “DD Wizard”), as well as an Energy Efficiency
Measure wizard (the “EEM Wizard”). It’s like having an expert advisor, operating
between you and the DOE-2 energy simulation program. Either Wizard will guide you
through a series of steps designed to allow you to fully describe the principal energyrelated
features of your design. The wizards then create a detailed description of the
proposed design as required DOE-2. At each step of describing your building design, the
wizards provide easy-to-understand choices of component and system options.
EQUEST calculates hour-by-hour building energy consumption over an entire
year (8760 hours) using hourly weather data for the location under consideration. Input

36
to the program consists of a detailed description of the building being analyzed,
including hourly scheduling of occupants, lighting, equipment, and thermostat settings.
EQUEST provides very accurate simulation of such building features as shading,
fenestration, interior building mass, envelope building mass, and the dynamic response
of differing heating and air conditioning system types and controls.
EQUEST also contains a dynamic daylighting model to assess the effect of
natural lighting on thermal and lighting demands. The simulation process begins by
developing a "model" of the building based on building plans and specifications. A base
line building model that assumes a minimum level of efficiency (e.g., minimally
compliant with California Title24 or ASHRAE 90.1) is then developed to provide the
base from which energy savings are estimated. Alternative analyses are made by making
changes to the model that correspond to efficiency measures that could be implemented
in the building. These alternative analyses result in annual utility consumption and cost
savings for the efficiency measure that can then be used to determine simple payback,
life-cycle cost, etc. for the measure and, ultimately, to determine the best combination of
alternatives.
3.2.1 Using EQUEST 3.6
Before "build" anything, including simulation model, first consider and
collect the following step :

37
Analysis Objectives: Try to approach your simulation model with a clear
understanding of the design questions you wish to answer using your simulation
model. Simplifications that you build into your model will both uncluttered your
model so you can focus on the important issues and at the same time, limit the
questions you can use your model to answer. Experience will teach you how best
to strike this important balance for each new project.
Building Site Information and Weather Data: Important building site
characteristics include latitude, longitude and elevation, plus information about
adjacent structure or landscape capable of casting significant shadows on our
proposed (or existing) building.
Building Shell, Structure, Materials, and Shades: EQUEST is interested in the
walls, roof, and floor of your proposed building only in so far as they transfer or
store heat .You will need to have some idea of the geometry (dimensions) and
construction materials of each of the heat transfer surfaces in your proposed
building. Only the most significant need be included (e.g., many modelers omit
parapet walls or walls inclosing unconditioned spaces since they do not directly
enclose conditioned space). This will include glass properties of windows and
the dimensions of any window shades (e.g., overhangs and fins). EQUEST
provides users with simple, user-friendly, choices for each of these.
Building Operations and Scheduling: A clear understanding of the schedule of
operation of the existing or proposed building is important to the overall
accuracy of your simulation model. This includes information about when
building occupancy begins and ends (times, days of the week, and seasonal
variations such as for schools), occupied indoor thermostat set points, and HVAC
and internal equipment operations schedules. EQUEST defaults operations
schedule information based on building type.

38
Internal Loads: Heat gain from internal loads (e.g., people, lights, and
equipment) can constitute a significant portion of the utility requirements in large
buildings, both from their direct power requirements and the indirect effect they
have on cooling and heating requirements. In fact, internal loads can frequently
make large buildings relatively insensitive to weather. More importantly, the
performance of almost all energy-efficient design alternatives will be impacted
either directly or indirectly by the amount of internal load within a building.
Although EQUEST contains reasonable defaults by building type, the
experienced user will take care to estimate these as carefully as possible.
HVAC Equipment and Performance: Few model components will have as
much influence on overall building energy use and the performance of most
energy-efficient design alternatives as will the HVAC (Heating, Ventilating, and
Air Conditioning) equipment. It follows that good information regarding HVAC
equipment efficiency will be important to the accuracy of any energy use
simulation. EQUEST assumes default HVAC equipment efficiencies according
to California's Title 24 energy standard. Where possible, equipment efficiencies
specific to each analysis should be obtained, e.g., from the building design
engineers or directly from equipment manufactures. Most HVAC equipment
manufactures now publish equipment performance data on their web sites.
Utility Rates: A great strength of detailed energy use simulation using EQUEST
is the ability to predict hourly electrical demand profiles that can then be coupled
with full details of the applicable utility rates (tariffs). EQUEST comes with the
principal residential and commercial electric and natural gas rates from the
sponsoring California utilities. For California locations (weather file selections),
EQUEST defaults the rate selection depending on climate zone and on estimated
peak electrical demand. Users outside California must create their own utility
rate descriptions using Quest’s DOE-2-derived Building Description Language
(BDL) and save these descriptions as text files for EQUEST's use.

39
3.2.2 Main Screen: Schematic Design Wizard
Users may elect to begin the building simulation process by using the Schematic
Wizard. The sequence of steps the wizard takes you through allows you to describe the
building’s architectural features and it’s heating, ventilating, and air-conditioning
(HVAC) equipment. The steps are organized so that the most general project
information is requested first (Figure 1), followed by more detailed architectural and
HVAC information (Figures 2 and 3).
Figure 3.7 : General information
1) Project Name: Select a project name - used to name the project files and project
folder.

40
2) Building Type: This selection is used to set defaults for most wizard inputs
that follow, e.g., building size, HVAC system type(s), etc.
Changing this selection will cause user inputs entered
"downstream" to be reset.
3) Weather file Coverage :There are three choices: "California/Title24"
(limits the choices to the 16 California climate zones),
"All EQUEST Locations" (provides U.S.-wide coverage),
and "User Selected" (allows the user to browse his/her
machine for any DOE-2 weather files). If the selected
weather file is not on the local hard drive, when the
simulation is initiated, EQUEST asks permission to
initiate an automatic download of the weather file from
the DOE-2.com ftp site.
4) Utility/Rates: For California/Title24 coverage, EQUEST automatically
selects the utility and rate based on the selected region and
building size.
5) Number of Floors: For # floors above grade > 3, EQUEST models only 3
floors and uses a multiplier on the middle (typical) floor.
6) Cooling/Heating: Selecting the coil types will default the available HVAC
system types and plant equipment (if any).
7) Day lighting: Enables/disables day lighting-related screens.
8) Usage Details: Simplified are On/Off step function schedules, Hourly Endue
Profiles allow hour-by-hour variation of usage profiles.

41
3.2.3 Building footprint
Figure 3.8: Building footprint
1) Footprint Shape: Select a preferred standard building footprint shape, then
edit the footprint dimensions, or select "custom" and either
draw a custom footprint from scratch or customize one of the
standard footprints. Note that six floor areas are reported: the
first based on Bldg Area / # Floors (from previous screen) and
the second based on the dimensions entered on this screen.
Currently, the selected footprint shape applies to all floors in
project. This limitation will be relaxed in the future.

42
2) Zoning Pattern: Currently, there are three options: perimeter-vs-core, one perfloor,
and "custom". For perimeter vs core zoning, use Perimeter
Zone Depth to alter the depth of all perimeter zones. Alternately,
Select "custom" and either draw a custom zoning pattern from
scratch or customize one of the standard zoning patterns (see
below). More detailed automatic zoning options will be available
in the future.
3) Building Orientation: Note that this input describes the direction that "Plan
North" faces, i.e., this is the compass direction that the top
of the plan sheet actually faces. Confirm that you have
selected this correctly by referring to the North arrow (true
north) on the building footprint diagram.
4) Floor Heights: Note that these heights apply to all floors in the project.
5) Pitched Roof: Use this to specify a hip roof (accepts only Roof Pitch in
degrees, and roof overhang projection). Gable ends and other
options will be added in the future.
3.2.4 Customized Building Footprint
We can customize an already-selected building footprint shape (the example on
this page), or you can start from scratch to create a completely custom building footprint
shape.

43
1) Footprint Shape (standard shapes): To customize a previously selected
"standard" building footprint (any of the
choices on the Footprint Shape pull-down
list), from the Building Footprint screen, pull
down the Footprint Shape list and select any
of the standard shapes.
2) Footprint Shape (custom shapes): Having first selected a preferred standard
shape and having modified its dimensions as
desired, pull down the Footprint Shape list
again and select "-custom-".
3) Custom Footprint Initialization Options: After selecting "custom" from the
Footprint Shape list, an initialization
dialog will appear. To customize a
standard building footprint shape, select
Start With… "Previously Defined
Footprint". But in my design, I use
my AutoCAD file(.DWG) that I drew
first before run this software (EQUEST).
So, I select blank slate and use my
AutoCAD file as “Background image”.

44
Figure 3.9: Customized Building Footprint
my AutoCAD file
Figure 3.10: Custom Footprint Initialization Options

45
Figure 3.11: Custom Building Footprint
1) Drawing Control Buttons: Use these buttons in the upper left
area of the screen to select vertices, to zoom, and to
pan.
2) Zoom Button : Select the zoom button then use the left mouse button to
make a vertical "stroke" on the drawing image. A downward
mouse stroke zooms back. An upward stroke zooms in. Zoom
back to give some extra room to customize the standard shape.
Pan
as preferred.

46
3) Select vertices: Select the pointer button, then single click on any existing
vertex in the drawing (do not double click). Vertices will appear
in one of three colors:
• Red (i.e., not the currently selected vertex),
• Light Blue (i.e., currently selected and ready to copy), or
• Yellow (i.e., currently selected and ready to move).
Left mouse clicks toggle the selected vertex between light blue
and yellow.
4) Move an existing vertex: Select any vertex. Make it yellow (by single
clicking as needed… do not double click). Drag the
yellow vertex to a new preferred location.
5) Create a new vertex: Select any vertex. Make it light blue (by single clicking
as needed. Do not double click). Drag the light blue
vertex to a new preferred location.
6) Repeat steps 2 through 5 as preferred

47
3.2.5 Exterior Windows
Define my own design based on the case study building (ANG’s Building)
Figure 3.12: Exterior Windows
1) Window Area Specification Method :Use this to indicated whether the
window-wall ratio percentages are based on
floor-to-floor (the default and applicable for
most building energy codes) or floor-toceiling
dimensions.

48
2) Glass Category and Type: Select “specify properties” and define our own
glass type using either NFRC SHGC and U-factor
(includes frame), or ASHRAE Shading Coefficient and
U-Value (normally treated as exclusive of the frame).
Select “Window4/5 data” if you wish to use
(i.e., import glazing systems defined using WINDOW4
or WINDOW 5 . For this part, I use glazing properties
which is from my simulation using Window 5.2a. So, I
just put that value in the box.
3) Frame Types: Window frame type selections are per the ASHRAE Handbook of
Fundamentals. (When using NFRC glass properties, frames are not
modeled, i.e., frame inputs are ignored).
4) % Window :. To accommodate large WWR %’s, decrease Sill Ht. and Frame
Wd., and increase Window Ht.
5) Typical Window Width: Use this to indicate multiple, identical, windows
of a preferred typical width. Typical Window Width = 0
yields one long window per window type (3 max) per
façade. On exterior walls where doors are also placed
(centered), the window is "split" around the door(s).
If we want our own design based on the case study building, we can design the
window arrangement by click to “custom window / door replacement” as shown in
figure 3.12. Figure 3.13 shows that the design based on my case study building (Ang’s
building).

49
Figure 3.13: Custom Window / Door replacement view test
3.2.6 Activity Areas Allocation
EQUEST users specify internal loads (lights, people, and equipment) via
"activity areas". EQUEST then allocates these loads to each HVAC zone according to
default or user-specified allocations for each activity area (by % of the total building).

50
Figure 3.14 : Activity Areas Allocation
1) Area Types: Select activity area types from the list of available area types. This
list was developed from regulatory/code sources, e.g., ASHRAE,
CEC. Select up to eight area types.
2) Percent Area: Indicate a percent allocation for each activity type (must sum to
100%). Default percentages are based on selected building type.

51
3) Design Occupant Density and Ventilation: Indicate preferred occupancy density
and outside air ventilation rates
(cfm per person). Defaults are based
on ASHRAE 62. Note that these
entries should be considered DESIGN
levels for each. If diversity is to be
applied for typical (not design)
operations, enter % occupancy, lights,
or equipment < 100% on the Schedule
Information screens
(Figure # 17 and 18).
4) Assignment Priority: Use these assignment priorities to control EQUEST's
allocation priorities. For example, a lobby activity area is
expected to be located in perimeter zones at the ground
floor. EQUEST will use these priorities but the percentage
assignments will take precedence.
5) Show/Enable Zone Group Definitions: Thus check box is used to enable the
Zone Group Definitions Screen
(figure 3.14). This is useful for more
detailed or custom assignment of Area
Types by zone.

52
3.2.7 Occupied Loads by Activity Area
1) Lighting, task Lighting, Plug Loads: Indicate/confirm peak loads for lights
(ambient and task) and plugs (equipment),
by activity area. These loads are normally
considered to be installed load. Defaults are
taken from California Title24 requirements.
2) Main/Alt Schedule flag: Use these "radio buttons" as flags to indicate whether
one or two usage schedules are necessary to describe
building usage patterns. These schedules will be
detailed on subsequent screens.
Figure 3.15: Occupied Loads by Activity Area

53
3.2.8 Main Schedule Information
EQUEST’s Schematic Design Wizard permits up to two building usage
schedules, a main schedule and an alternate schedule. This example employs only one
schedule (i.e., no alternate schedules indicated on the Occupied Loads screen, two
screens prior to this one). These building usage schedules are used to indicate to the
simulation engine the appropriate level of internal load for each hour of the year.
Figure 3.16: Main schedule information
1) Day 1 - day 3. Indicate how many day types are required to describe the building
usage, e.g., one day for hospitals (each day is equally occupied),
two days for office buildings (weekday and weekend days).

54
2) Occupancy/Lights/Equipment %: Indicate the level of load for people, lights,
and equipment during occupied hours
(as a percentage of installed load indicated on
previous screens).
3) Second Season: Check this box if you wish to specify a second schedule season.
The default second seasons are based on building type, e.g.,
summer for schools, December for retailers. Repeat the previous
two steps as necessary.
3.2.9 Result from EQUEST 3.6
Once a simulation has been completed, I visualize the results through a number
of graphical formats. Overall building estimated energy use can be seen on an annual or
monthly basis. Detailed performance of individual building components may also be
examined. Figure 3.17 and 3.18, shows the monthly electrical consumption for Ang’s
building with and without Smart Windows simulation and the fraction of that
consumption attributed to each of the end-use categories (lighting and cooling load).
Figure 3.19 and 3.20, on the other hand, provides a pair of comparison graphics
that show the monthly electrical consumption for Ang’s building with and without Smart
Windows simulations and the annually electrical consumption for Ang’s building with
and without Smart Windows simulations. For figure 3.21 and 3.22, there are the results
for monthly utility bills and also for the 3-D view of EQUEST model.

55
Figure 3.17: Monthly electrical consumption for Ang’s Building with
Smart Windows
Figure 3.18: Monthly electrical consumption for Ang’s Building
without Smart Windows

56
Figure 3.19 : Comparison Monthly electrical consumption between with and
without Smart Windows
Figure 3.20 : Comparison Annually electrical consumption between with
and without Smart Windows.

57
Figure 3.21: Monthly utility bills
Figure 3.22: 3-D view of EQUEST model for Ang’s Building

CHAPTER 4
PLAN AND STRATEGIES
4.1 Case Study Building: Ang’s Building
4.1.1 Base building profile
When conducting this research, Ang’s Building has been selected as a case study
building. I choose this building because it is the most suitable commercial building in
Johor Bharu to install Smart Windows due to the number of windows which is about
80% of this building is covered by windows. This building is located at Taman Tasek,
Johor Bharu, as shown in figure 4.1. Its owned by Tasek Development Sdn. Bhd. Ang’s
Building is classified as a hypothetical medium buildings which is it have 8 floors
including basement and ground floor. In this project, I only focus on 1 st floor to 6 th floor
of the building because of only those floors are covered by windows.

59
Figure 4.1: Ang’s building location
Figure 4.2: Ang’s building (Front view)
Figure 4.3 : Ang’s building (side view)

60
The total area for each floor is 1266.1880 m 2 , as shown in figure 4.4. A floor to
floor height is 3.75 m and a floor to ceiling height is also 3.75 m. The total number of
windows in this building is 1105 which is size per window is 1.579 m 2
(1.88 m x 0.84 m).
Figure 4.4 : Top view of Ang’s building (foot print)
Usually, this building open from Monday to Friday for the whole building while
on Saturday, only 5 th floor will be open. Sunday is non-working day. During the
weekdays, the electrical consumption was assumed operate from 8am to 6pm which is 1
hour before office hour (9 am) and 1 hour after office hour (5 pm). Its occupancy rate for
each floor is about 50 people per floor.

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4.1.2 Johor Bharu’s climatic conditions
The characteristic features of the climatic conditions of Johor Bharu are uniform
temperature and pressure, high humidity and copious rainfall. There are no great
temperature variations throughout the year. The daily range of temperature is moderate,
being of the order of 25°C at night to 32°C in the day, and is larger than the annual range
of temperature of about 1.7°C. Wind movements are mainly from North to Northeast
and South to Southeast, but spells of Westerly wind are also experienced. Hence, by
looking at the daily range of daytime temperatures, it can be concluded that office
buildings in Malaysia especially Johor Bharu ought to be air-conditioned to be within
the thermal comfort zone for the occupants. As such, the type of glazing used on the
building together with the building's orientation would have a significant impact on the
cooling and dehumidifying load of the air-conditioning system.
4.1.3 Building Orientation
Orientation of building is an important aspect when calculating the cooling load
of the building. Basically, walls facing East or West are exposed to the greatest amount
of solar heat load. Consequently, if glazing were used on these sides of the wall, the heat
load entering the building would be higher, which would inevitably demand a higher
cooling load from the air-conditioning system of the building. The efficiency of reduced
cooling load and total energy consumed with the use of the smart window glazing is
therefore studied via the EQUEST energy simulation programme.

62
4.1.4 Load Estimation
To obtain the cooling load of a building, the complex mechanisms of interactions
between the load and the systems and between the systems and the plants must be
modeled and assessed. The cooling load of a building can be determined from the
physical description of the different buildings, their operating schedules and systems.
After determining the cooling load, different possibilities of reducing this load can then
be identified. The calculation of the space cooling load is a complex operation and
involves the following. As a general guide, the procedures listed below should be
followed.
( 1 ) Obtain characteristics of the building: Building materials, component size,
external surface colours and shape are usually obtained from building plans
and specifications.
(2) Determine building location, orientation and external shading: Most of this
information can be obtained from plans and specifications. However, for
shading and reflected solar radiation from the surrounding, site visits should be
carried out.
(3) Obtain appropriate weather data and select outdoor design conditions: Weather
data can be obtained from local weather stations. As for outdoor design
conditions, it should be selected with regard to local weather data, economic
considerations and effects of departure from inside design conditions caused by
extreme variations in outdoor conditions.
(4) Determine heat sources within the conditioned space: A proposed schedule of
lighting, occupants, internal equipment, appliances and processes that would
contribute to the internal thermal load should be obtained.

63
(5) Calculate the space cooling load at design conditions: The cooling loads of the
Primary components are first calculated individually. It is then added together
to form the total cooling load of the building.
4.2 Simulation Result
Simulation was run based on the case study building using EQUEST 3.6 to make
comparison between after and before installation of Smart Windows. By using this
software, energy consumption and cooling load that required by the building can be
determined. Figure 4.5 shows the simulation result of electric consumption (kWh) for
Ang’s building with and without Smart Windows.
Figure 4.5: Electric Consumption (kWh)
monthly

64
From the graph in Figure 4.5, the total electric consumption annually for Ang’s
building without Smart Windows is 1,296,600 kWh. The electric consumption annually
of this building is estimated to decrease about 33.26 % when the Smart Windows is used
which is decrease to 865,400 kWh. The differences between these two figures yields the
total of annual electric consumption saving will become 431,200 kWh.
Figure 4.6 shows the result of annual energy consumption for Ang’s building
produced by lighting and cooling load. From the graph, the annual energy that consume
by cooling load without Smart Windows is about 600,800 kWh but with Smart
Windows, energy can be save until 31.61% which is by decreasing to 410,890 kWh. For
lighting load, by looking at Figure 4.6, we can see that the annual energy consumption is
reduced from 417,700 kWh to 289,800 kWh after the implementation of Smart
Windows into Ang’s building. It means that it can saves about 30.62% of lighting load.
Actually, there are others load that also contributed to energy consumption in
commercial building such as internal equipment, appliances, refrigeration, fans and
etc.But in this project, I only focus on cooling and lighting load because of these two
load is the largest consumer of electricity in most commercial buildings.
From all the result, it is clear that by implementing the Smart Windows in this
building will benefit from an abundance of natural daylight and also have large
reduction in cooling and lighting load make Malaysia, especially Johor Bharu as an ideal
place to implement this new technology.
Figure 4.6: Annual Energy Consumption by Enduse

65
4.2.1 Annual Energy Cost Saving
The annual savings of Smart Windows is a total of reduction in lighting and
cooling loads. The energy savings is converted into MYR and is shown in the table 4.1.
TOTAL ENERGY
USED WITHOUT
“SMART WINDOWS”
(kWh)
TOTAL ENERGY
USED WITH “SMART
WINDOWS” (kWh)
TOTAL ANNUAL
ENERGY SAVING
(kWh)
COOLING LIGHTING ANG’S BUILDING
600,800 417,700 1,296,600
410,890 289,800 865,400
189,910 127,900 431,200
% ENERGY SAVING 31.61 30.62 33.26
UTILITY RATE
TARIFF B (RM / kWh ) 0.323 0.323 0.323
ANNUAL ENERGY
COST WITHOUT 194,058.40 134,917.10 418,801.80
“SMART WINDOWS”
(RM)
ANNUAL ENERGY
COST WITH “SMART 132,717.47 93,605.40 279,524.20
WINDOWS” (RM)
ANNUAL ENERGY
COST SAVING (RM) 61,340.93 41,311.70 139,277.60
Table 4.1: Annual Energy Cost Saving

66
Below is the calculation for the annual energy cost saving for lighting load:
Annual Energy Saving = Annual lighting load without Smart Windows –
Annual lighting load with Smart Windows
Annual Energy Saving = 417,700 – 289,800
= 127,900 kWh
For the Annual Cost Saving, the utility rate used is from TNB tariff B and is shown as
below:
Annual cost saving = 127,900 x 0.323
= RM 41,311.70
So, Percentage Energy Saving = (127,900/ 417,700) x 100%
= 30.62%
For the cooling load, the calculation for the annual energy saving, annual cost saving
and the percentage energy saved also same as lighting load and shown as follows:
Annual Energy saving = Annual Cooling load without Smart Windows –
Annual Cooling load with Smart Windows
Annual Energy Saving = 600,800 – 410,890
= 189,910 kWh
Annual Cost Saving = 189,910 x 0.323
= RM 61,340.93
So, Percentage Energy Saving = (431,200 / 417,700) x 100%
= 31.61%
Then, the total annual energy saving for Ang’s building is calculated as below:
Annual Energy Saving = Annual Energy used without Smart Windows –
Annual Energy used with Smart Windows
Annual Energy Saving = 1,296,600– 865,400
= 431,200 kWh

67
Annual Cost Saving = 431,200 x 0.323
= RM 139,277.60
So, Percentage Energy Saving = (431,200/ 1,296,600) x 100%
= 33.26%
From the table 1, the annual energy cost saving for Ang’s building after Smart
Windows was installed is RM 139,277.60 which is the cost saving for cooling load is
RM 61,340.93 and for lighting is RM 41,311.70.
4.2.2 Investment Cost and Payback Period
To implement the energy saving measurements successfully, investment cost is
needed. A total investment of “Smart Windows” system for Ang’s building is shown in
the table 4.2.
Building area , m 2 1266.27
Window size (area), m 2 1.579
Number of windows 1105
Window Cost (RM/m 2 ) 570
Cost per window (RM) 900.03
Total cost of smart windows for
Ang’s building (RM) 994,533.15
Maintenance Cost 9945.33
Total Saving Per Year 139,277.60
Payback Period (Year) 7.61
NPV 2,079,981.10
Table 4.2: Cost of construction

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Based on the information that I got from previous studies and from U.S DOE
(Department Of Energy), the cost for Smart Windows is RM 570 per meter square. So,
the cost per window is RM 900.03. Then, if this building has about 1105 windows, the
total cost of Smart Windows for Ang’s building will approximate to RM 1 million which
is about RM 994,533.15. For annual maintenance cost of windows, it is 1% from its total
cost which is about RM 9945.33 per annum. As we can see, the cost of construction and
its maintenance cost per annum are quite expensive. Even though this project too costly,
but for the long-term investment, it is profitable.
In order to prove that statement, calculation on payback period and NPV (Net
Present Value) are needed. Payback period is the number of years required to recover a
project’s cost. We can calculate the payback period as demonstrated in Table 3 and
calculation for payback period is given as follows:
Payback Period = Year before full recovery +
Unrecovered cost at start of year
Cash flow during year
= 7 + 79,261.93 = 7.61 years
129,332.27
From the calculation above, its payback period is about 7.61 years by assuming a cost of
capital is 12%. It means that it’s required only 7.61 years recovering the project’s cost
(investment for 60 years due to the life of glazing). The positive value of NPV in Table
4.3 shows that the long-term investment in Smart Windows for Ang’s building is
profitable and acceptable.

69
Year
Net Cash
Flow (NCF)
Rate Of Return,
1/(1+K) t
Cumulative Net
Cash Flow
Net Present
Value
0 -994,533.15 994,533.15
1 139,277.60 0.8929 -855,255.55 124355
2 129,332.27 0.7972 -725,923.28 103102.8938
3 129,332.27 0.7118 -596,591.01 92056.15519
4 129,332.27 0.6355 -467,258.74 82192.99571
5 129,332.27 0.5674 -337,926.47 73386.60331
6 129,332.27 0.5066 -208,594.20 65523.75295
7 129,332.27 0.4523 -79,261.93 58503.35085
8 129,332.27 0.4039 50,070.34 52235.13469
9 129,332.27 0.3606 179,402.61 46638.51312
10 129,332.27 0.322 308,734.88 41641.52957
11 129,332.27 0.2875 438,067.15 37179.93711
12 129,332.27 0.2567 567,399.42 33196.37242
13 129,332.27 0.2292 696,731.69 29639.61823
14 129,332.27 0.2046 826,063.96 26463.94485
15 129,332.27 0.1827 955,396.23 23628.52219
16 129,332.27 0.1631 1,084,728.50 21096.89481
17 129,332.27 0.1456 1,214,060.77 18836.51323
18 129,332.27 0.13 1,343,393.04 16818.31538
19 129,332.27 0.1161 1,472,725.31 15016.35302
20 129,332.27 0.1037 1,602,057.58 13407.45805
21 129,332.27 0.0926 1,731,389.85 11970.94469
22 129,332.27 0.0826 1,860,722.12 10688.34347
23 129,332.27 0.0738 1,990,054.39 9543.163814
24 129,332.27 0.0659 2,119,386.66 8520.681977
25 129,332.27 0.0588 2,248,718.93 7607.751765
26 129,332.27 0.0525 2,378,051.20 6792.635505

70
27 129,332.27 0.0469 2,507,383.47 6064.853129
28 129,332.27 0.0419 2,636,715.74 5415.047437
29 129,332.27 0.0374 2,766,048.01 4834.863783
30 129,332.27 0.0334 2,895,380.28 4316.842663
31 129,332.27 0.0298 3,024,712.55 3854.323806
32 129,332.27 0.0266 3,154,044.82 3441.360542
33 129,332.27 0.0238 3,283,377.09 3072.643341
34 129,332.27 0.0212 3,412,709.36 2743.431554
35 129,332.27 0.0189 3,542,041.63 2449.492459
36 129,332.27 0.0169 3,671,373.90 2187.046838
37 129,332.27 0.0151 3,800,706.17 1952.720391
38 129,332.27 0.0135 3,930,038.44 1743.50035
39 129,332.27 0.012 4,059,370.71 1556.696741
40 129,332.27 0.0107 4,188,702.98 1389.907804
41 129,332.27 0.0096 4,318,035.25 1240.989111
42 129,332.27 0.0086 4,447,367.52 1108.025992
43 129,332.27 0.0076 4,576,699.79 989.3089213
44 129,332.27 0.0068 4,706,032.06 883.3115369
45 129,332.27 0.0061 4,835,364.33 788.671015
46 129,332.27 0.0054 4,964,696.60 704.1705491
47 129,332.27 0.0049 5,094,028.87 628.7237046
48 129,332.27 0.0043 5,223,361.14 561.3604505
49 129,332.27 0.0039 5,352,693.41 501.214688
50 129,332.27 0.0035 5,482,025.68 447.5131143
51 129,332.27 0.0031 5,611,357.95 399.5652806
52 129,332.27 0.0028 5,740,690.22 356.7547148
53 129,332.27 0.0025 5,870,022.49 318.5309954
54 129,332.27 0.0022 5,999,354.76 284.4026744
55 129,332.27 0.002 6,128,687.03 253.9309593

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56 129,332.27 0.0018 6,258,019.30 226.7240708
57 129,332.27 0.0016 6,387,351.57 202.4322061
58 129,332.27 0.0014 6,516,683.84 180.7430412
59 129,332.27 0.0012 6,646,016.11 161.3777153
60 129,332.27 0.0011 6,775,348.38 144.0872458
TOTAL 6,775,348.38 TOTAL NPV 2,079,981.10
Table 4.3: Payback Period Calculation

CHAPTER 5
CONCLUSION AND RECOMMENDATION
5.1 Conclusion
Industrialisation certainly acts like a two-edged sword. On the one hand,
countries rely on it to maintain competitiveness in today's global economy to ensure that
human needs and wants are met, whereas on the other, the consequences of global
warming as a result of rapid industrialisation is threatening to outbreak into a worldwide
ecological calamity. The signs are already there. Melting ice-caps at the poles are
continuing to push sea levels up and swamp coastal dwellings, the increasing depletion
of the ozone layer allowing more harmful ultraviolet (UV) radiation to penetrate, are just
some of the harsh realities the world is facing today.
Smart windows in a daylit building not only can save annual operating costs but
can reduce the initial cost of some major building components as well. The chillers that
provide cooling in most commercial buildings are a major cost, and chiller size is
directly related to cooling loads from windows. Properly designed and managed
windows have the technical potential to save 30-40% of the lighting and cooling load. It

73
means, they have the technical potential to save 30-40% from total annually energy
consumption: a significant advance in conventional technology.
It can be proved by doing the economic analysis (analysis on Ang’s building).
From the economic analysis, total annually energy saved in the Ang’s building by
implementing the Smart Windows is estimated about 431,200 kWh, the cost of the
saving is about RM 139,277.60. Percentage of the total energy saved is 33.26%. The
total cost of Smart Windows for Ang’s building is RM 994,533.15 and the detail of the
calculation is attached in Appendix A. The payback period as show in chapter 5 is about
7.61 years. Indeed the cost quite expensive which is about 1 million MYR, however for
the long-term investment, it is profitable. It is because it required only 7.61 years
recovering the project’s cost (investment for 60 years due to the life of glazing). The
shorter the payback period is the better. Besides, this project (installation of Smart
Windows) will be accepted since the value of NPV (Net Present Value) is positive.
Smart glazing would generally be more expensive than conventional glazing.
However, reduction in cooling devices may provide first-cost savings that can offset
some of the costs of electric lighting controls. With the projected increase in energy
consumption in Malaysia, greater responsibility has been placed on building services
engineers, chief architects, estate managers and all those charged with the task of
reducing energy costs in buildings under their care, to exercise considerable skill and
judgment in identifying those efficiency improvement measures that are appropriate to
their particular circumstances.
The increasing call for intelligent buildings in view of economics, visual
appearance and occupant comfort have also resulted in the need for more modem and hitech
building materials one of which is Smart window. In the humid equatorial climate
of Malaysia, the shaded air temperature is quite constant throughout the year, and the
difference between outdoor and controlled indoor air temperature is not high. Solar heat
gain is therefore the single most important factor to be considered in the building design.

74
It has been demonstrated in this project that smart windows can achieve the reduction of
this solar heat load in a cost effective manner.
5.2 Recommendation and future work
1. In the designing process of Smart Windows, it focus on the glazing selection
which is only the most efficient glazing will be selected to produce this Smart Windows.
So, as the result, indirectly it had neglected other factors such as the suitability type of
window frame, type of windows operation whether awning, casement, double hung,
hopper or slider and also other factors that will give big impact to the window
production for energy efficiency purpose. So, for future studies, it should be more
concentrate on the other factors that it stated before. With not neglecting them, it will be
able to produce more accurate analysis subsequently high performance Smart Windows
will be produce.
2. In term of software (EQUEST 3.6 and WINDOW 5.2a), more detailed studies
must be implemented to make sure that the achieved result perfectly accurate and
efficiently. For example, while using the software, lack of information about the data of
weather file for my case study area (Johor Bharu) happen. So, as the alternative way, try
to use KL weather file for my case study. It is because, that software was got from one
of the staff from US DOE (Department Of Energy) and according to him, they only
created one weather file for each country. So for next studies, suggest that this software
should be more learned well by detailed from every single part and use all the features in
this software in appropriate way. The good selection and proper use of this software will
help us to obtain more accurate output.

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3. Finally, for future studies also, proposed that a guideline or road map should be
prepared for Malaysian researcher, builder, and manufacturer as their references for
future development. That guideline or road map could be implemented by using any
suitable software such as Visual Basic, Macromedia Flash, and etc. Additionally, for
advanced study, this Smart Windows should be modeled by real design (or prototype) so
that the result can be experimented with real environment subsequently the result will
produce more precisely.

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REFERENCES
[1] "Shading and Sun Controls." Architect's Handbook of Energy Practice.
Washington, DC: 1982.
[2] Amstock, J.S. Handbook of Glass in Construction. New York: McGraw Hill,
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[3] Ander, Gregg D. Daylighting Performance and Design. New York: Van
Nostrand Reinhold, 1995.
[4] Daylighting Performance and Design, 2nd ed. New York: John Wiley &
Sons, 2003.
[5] Benson, D. and E. Tracy. "Wanted: Smart Windows that Save Energy,"
NREL in Review, June 1992.
[6] CEA. Energy-Efficient Residential and Commercial Windows Reference
Guide. Montreal, PQ: Canadian Electricity Association, 1995.
[7] Cerver, Francisco Asensio. The Architecture of Glass: Shaping Light. New
York: Hearts Books, 1997.
[8] Cooper J. R., T. J. Wiltshire and A. C. Hardy. "Attitudes toward the use of
heat rejecting/low light transmission glasses in office buildings." CIE TC-4.2
Proceedings of the Symposium on Windows and their Function in
Architectural Design. Brussels: Committee Nationale Belge de l'Eclairage,
1973, V1-7.

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[9] Harrison, S., and S. van Wonderen. "A Test Method for the Determination of
Window Solar Heat Gain Coefficient." ASHRAE Transactions 100, no. 1
(1994).
[10] Johnson, Timothy. Low-E Glazing Design Guide. Boston: Butterworth-
Heinemann, 1991.
[11] S.C. Sekhar and Kenneth Lim Cher Toon, “On the study of energy
performance and life cycle cost of smart window”, School of Building and
Real Estate, National University of Singapore, 10 Kent Ridge Crescent,
Singapore 119260, Singapore, April 1998.
[12] Cuttle, Kit. "Subjective assessments of the appearance of special performance
glazing offices." Lighting Research and Technology 11 no. 3 (1979): 140-49.
[13] Energy Information Administration. A Look at Commercial Buildings in
1995: Characteristics, Energy Consumption, and Energy Expenditures.
DOE/EIA-0625(95). (October 1998). U.S. Department of Energy,
Washington, D.C. 20585.
[14] DOE-2 Supplement, Version 2.1E, Building Energy Simulation Group,
Lawrence Berkeley Laboratory, 1994.

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APPENDIX A
Daily consumption (RM) for ANG’s Building :

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APPENDIX B
Site and Location plan :

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APPENDIX C
1 st to 5 th typical floor plan :

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APPENDIX D
6th floor plan :