EFFECT OF INTERNAL SHADING DEVICES TOWARDS BUILDING ENERGY EFFICIENCY IN HOT AND HUMID CLIMATE

Nurafina Binti Safri

Master of Engineering 2010

Pusat Khidmat MlkJumat Abdftn'" ; -• .. . • T <::rrr UT . ~v<:' S~R U '

P-KHIDMAT MAKLUMAT AKADEMIK

'11'"III 1111111000246290

EFFECTS OF INTERNAL SHADING DEVICES TOWARDS BUIDING ENERGY EFFICIENCY IN HOT AND HUMID CLIMATES

NURAFINA BINTI SAFRI

This project is submitted in fulfillment of the requirements for Master of Engineering (Energy and Building)

Faculty of Engineering UNIVERSITI MALAYSIA SARA W AK

2010

To my belovedfamily andfiance

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ACKNOWLEDGEMENT

Fullest gratitude to Allah, the most Gracious and Merciful for giving me a chance , and strength to complete this project on time.

I wish to express my greatest appreciation to my supervisor, Dr Azhaili Baharun

and my co-supervisor, Dr Siti Halipah Ibrahim for their guidance, advices,

comments and suggestions throughout this whole process.

lowe a big thanks to the staff of Building Services Laboratory of Civil

Engineering, Mr. Mohd Rozaini for his dedication and kindness for helping me

setting up field measurement's apparatus.

I would also like to acknowledge with gratitude to my family especially my

beloved mother and father for their endless love, invaluable moral and financial

support throughout my entire life.

Finally, for the loved one, thank you for your patience and love.

Thank you so much.

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ABSTRACT

( Energy Efficiency is important to ensure our country's natural resources are adequate

for future generation. Data in annual statistic from Malaysia Energy Commission

shows that commercial buildings, such as an office building, are the second largest

consumers of the electricity in this country. Transparent envelope of the building is

determined to be the largest factors on cooling load placed on building's air

conditioning system. The glazing area allows the admission of solar heat gain through

radiation and conduction which causing the excessive usage of electricity by a chiller

to keep to the set temperature in bUilding. Tabuan Height Commercial Centre was

modeled in the simulation software and it was validated against the field

measurement) rhe validated model was used to simulate various options of internal

shading devices and their effect on building energy consumption. Results of this

study show that internal shading devices do contribute as much as 31.3 percent of

energy saving annually by controlling solar admission into the building.

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ABSTRAK

Penggunaan tenaga elektrik secara effisien adalah penting bagi menjamin bekalan

sumber asli negara mencukupi untuk generasi yang akan datang. Menurut statistik

tahunan oleh Suruhanjaya Tenaga Malaysia, bangunan komersial seperti bangunan

pejabat adalah pengguna kedua terbesar tenaga elektrik di negara ini. Penggunaan

tingkap kaca yang besar telah dikenal pasti sebagai penyumbang utama beban

penyejukan oleh sistem penghawa dingin. Tingkap kaca ini membenarkan haba dari

sinaran matahari secara radiasi and konduksi ke dalam sesebuah bangunan. Ini

menyebabkan sistem penghawa dingin di dalam bangunan tersebut meggunakan

lebih tenaga elektrik bagi memastikan suhu di cialam bangunan mencapai paras yang

telah ditetapkan. Pusat Komersial Tabuan Height telah dijadikan model kajian

simulasi perisian dan datanya disahkan berciasarkan bacaan data lapangan. Model

kajian simulasi yang diakui sahih kemudiannya digunakan untuk menjalankan

pelbagai simulasi alat pelindung dalaman dan kesannya ke atas penggunaan tenaga

bangunan. Hasil ujikaji kajian menciapati alat pelindung cialaman menyumbang

sebanyak 31.3 peratus penjimatan tenaga tahunan melalui mengawal pancaran

cahaya matahari ke atas bangunan.

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PUjat KWdmat M umat Akademih VNlVERSm MALAYSIA SARAWAJ(

TABLE OF CONTENT

Content

APPROV AL LETTER

APPROVAL SHEET

TITLE PAGE

DEDICATION SHEET

ACKNOWLEGDEMENT

ABSTRACT

TABLE OF CONTENT

LIST OF TABLE

LIST OF FIGURE

CHAPTER 1. INTRODUCTION

1.1 Introduction

1.2 Energy Consumption

1.3 Energy Production

1.4 Environmental Issues

1.5 Aim and Objectives of Study

1.6 Structure of the Thesis

CHAPTER 2. LITERATURE REVIEW

2.1 Introduction

2.2 Energy Efficiency Policy and Building Codes

2.3 Factors Affecting Energy Consumption of Building.

2.4 Energy Efficiency and Human Comfort

2.5 Shading Devices and Their Impact on Thermal Condition

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Page

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iii

iv

vi

ix

x

1

3

5

7

8

9

II

12

15

27

29

2.5 Building Simulation Programme 31

2.6 Validation of Simulation Model 34

2.7 Summary 36

CHAPTER 3. METHODOLOGY

3.1 Introduction 38

3.2 Building Energy Simulation Software Selection 39

3.3 Methodology 41

3.4 Summary 50

CHAPTER 4. RESULTS AND DISCUSSION

PROGRAMME, ENERGYPLUS

4.1 Introduction 51

4.2 Description and Justification ofthe Selected Building 52

4.3 Building Simulation Model ofTabuan Height Commercial 56

Center

4.4 Field Measurements 58

4.5 Simulation of the Building Model 62

4.6 Validation of Building Simulation against Field 63

Measurements

4.7 Energy Conservation Opportunity 82

4.8 Summary 84

VB

CHAPTER 5. STUDY ON THE EFFECT OF INTERNAL

SHADING DEVICES ON BUILDING ENERGY

CONSUMPTION USING COMPUTER SIMULATION

5.1 Introduction 85

5.2 Input Data for Simulation 86

5.3 Effectiveness of Window Shading Devices on Building Cooling 88

Load

5.4 Integration of Window Blind and Daylighting Provision 98

5.5 Conclusion 110

CHAPTER 6 CONCLUSIONS AND RECCOMENDA nONS

6.1 Introduction 111

6.2 Optimum Distance from Glazing Area for Effective Energy 112

Consumption

6.3 Optimum Slat Angle for the Integration of Daylighting 114

6.4 Energy Conservation by Internal Shading Devices 115

6.5 Building Simulation Programme: EnergyPlus version 2.1 117

6.6 Factor Affecting Energy Consumption of the Office Building 118

6.7 Recommendation For Future Work 120

REFFERENCES 122

APPENDICES

Appendix I : Actual Weather Data 135

Appendix II : Glass Performance Data 137

Appendix III : Input Data for Chiller 139

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Appendix IV : Statistical Analysis 140

Appendix V : Internal Shading Devices Properties 143

Appendix VI : EnergyPlus Output Example 144

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LIST OF TABLES

Table Page

Table 1.1 Fuel Mix in Electricity Generation, 2000-2010 6

Table 6.1 Energy Saving by Internal Shading Devices 116

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LIST OF FIGURES

Figure Page

Figure 1.1 Primary Energy Consumed in Office Building 4

Office Building

and Conduction

heat absorption.

building envelope

Indoor Temperature in Office Room A.

Indoor Temperature in Office Room B

on a Typical Day

Figure 2.1 Cooling Load Components for a Typical 930 m2 16

Figure 2.2 Solar Heat Gain through Glazing Area by Radiation 19

Figure 2.3 Whitewashing a dark wall reduces 60 percent of the 23

Figure 3.1 Flow Chart of Methodology 44

Figure 3.2 Data logger recorded thermal response of the 47

Figure 3.3 Thermocouples locations 47

Figure 3.4 Wattmeter Connected to the Chiller 48

Figure 4.1 View of the building from the East Fa~ade 55

Figure 4.2 The Experimental Room's Floor Plan 58

Figure 4.3 Office Room A 59

Figure 4.4 Office Room B 60

Figure 4.5 Thermocouple's Location 61

Figure 4.6 Comparisons between Measured and Simulated 64

Figure 4.7 Comparisons between Measured and Simulated 65

Figure 4.8 Indoor Temperature Performance of Office Room B 66

Figure 4.9 External Wall Surface Temperature of Office Room 68

B

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Figure 4.10 External Wall Surface Temperature Performances of 70

Office Room B on a Typical Day

Figure 4.11 Thermal Response of Roof Component in Office 72

RoomB

Figure 4.12 Surface Roof Temperature Performances on a 73

Typical Day

Figure 4.13 Comparisons between Measured and

Indoor Temperature in Office Room A

Figure 4.14 Comparisons between Measured and

Indoor Temperature in Office Room B.

Figure 4.15 Comparisons between Measured and

Simulated 75

Simulated 76

Simulated 77

Energy Consumption of the Chiller in Office Room

B.

Figure 4.16 Energy Consumption of the Chiller in Office Room 78

B on a Typical Day

Figure 4.17 Comparisons between Indoor Measured 80

Temperature in Office Room A and Office Room B

when Internal Blind Applied on the Window

Figure 4.l8 Comparison oflndoor Temperature Performances of 81

Office Room A and Office Room B on a Typical

Day with Internal Blind Applied on Office Room

B's Glazing Area

Figure 5.1 Total Energy Consumption for the Tested Draperies 89

Figure 5.2 Total Energy Consumption for the Tested Various 91

Types of Window Shade

Figure 5.3 Total Energy Consumption for the Tested Various 92

Types of Window Blind

Figure 5.4 The Effect of STG distance on Energy Saving 94

Figure 5.5 The Effect of BTG distance on Energy Saving 96

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Figure 5.6 Locations of the Reference Points for Oaylighting 99

Illumination

Figure 5.7 The Integration of Slat Angle with Oaylighting 91

Illuminance Level at Reference Point 1

Figure 5.8 The Integration of Slat Angle with Oaylighting 102

Illuminance Level at Reference Point 2

Figure 5.9 The Integration of Slat Angle with Daylighting 102

Illuminance Level at Reference Point 3

Figure 5.10 Locations of the Installed Lighting Points and 105

Reference Points for Day Lighting

Figure 5.11 Total Energy Consumption's Breakdown for the 106

Tested Five Cases

Figure 5.12 Annual Energy Consumption and Total Building 108

Load for the Tested Five Cases

Figure 5.13 Annual Energy Saving for the Tested Five Cases 109

I

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CHAPTER ONE

INTRODUCTION

1.1 Introduction

Commercial and residential buildings are estimated to consume approximately 36

percent of the world's primary energy (World Energy Outlook, 2008). Energy

consumption in buildings is generally high in industrialized countries, but comparatively

low in developing countries of Asia. However, over the past two decades, energy

consumption in commercia} and institutional buildings in Asia has grown rapidly,

particularly in the urban metropolitan centres of these developing countries (APEC

Outlook, 2006).

As Malaysia moves towards a developed country in 2020, energy requirements

will remain very severe as more buildings to be constructed while the supply source

(fossil fuel) for energy is expected to decline every y~ar (Lin el ai, 2006). At present,

almost half the energy consumption in the nation is consumed by the industrial,

residential and commercial sectors. Commercial buildings alone, accounts for about 13

percent of total energy consumption and 48 percent of electricity consumption (Abdul

Rahman, 2005). Malaysia current policy in developing knowledge-based economy to

reduce it dependency on the industrial sector, will result in increasing number of research

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and learning institutions as well as office buildings. This means Malaysia has a strong

need and great potential to apply energy efficient strategies in lowering energy

consumption in buildings.

Saving energy usage in building requires cooperation. All parties induding

architects, engineers, interior designers and researchers play important roles to mold

ideas into the creation of energy efficient building. Often, aesthetical value and cost

barrier are the main reasons it is not being implemented in Malaysia. Modem architecture

favours buildings with large ratios of glazing to floor area allow uncontrollable solar

radiation that lead to inefficient energy consumption in a building (Tinker, 2002) and

(Ismail, 2004).

As transparent building becoming a popular trend in Malaysia, the large glazed

surface become the weak spot of the building as it was found to be the main elements that

contributes to high cooling load in office building (Ossama et ai, 1997). The answer often

is the installation of costly and energy consuming air conditioning units to provide

comfortable ambient working place in an office building. However, due to hot and humid

climate of Malaysia, the installation of air conditioning units in office building is

undeniable. Therefore, efficient gains by allowing certain amount of dayJighting but

reducing solar radiation emission in building are likely to provide the greatest energy

reduction and in many cases will be the most economical answer.

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Shading the glazing area is the most effective way to achieve good indoor climate

condition with minimal energy consumption. The significant of glazing area toward

energy consumption would be discussed in detailed in literature review. Two types of

solar shading devices are external and internal shading devices. Studies on the

effectiveness of external solar shading devices in Malaysia are widely reported (Ku

Hassan, 1996; Kamal, 1997 and Ossen et ai, 2005). In contrast, inadequate information

on the role of internal shading devices toward energy efficiency was found. Hence, this

study assesses the effectiveness of internal shading devices on energy saving in an office

building.

1.2 Energy Consumption

Depending on climatic condition, heating, cooling, lighting and office equipments

are essential purposes of which energy is required in office building. Air conditioning

systems are discovered to be the main consumer of energy in Malaysia's office building

(Bateni, 2004 and, Yusof and Mustapa, 2005). Studies on energy efficiency in office

buildings found that 61 percent of the building in this country is inefficient (Wee, 2003

and Malaysia Energy Centre, 2004). Efficiency in building is determined by the pattern

of energy use. The typical energy usage breakdown in office building of Malaysia is as

presented in Figure 1.1.

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Primary Energy Consumed in Office Building

• Air Conditioning

16%

• Lighting

52% Office Equipmmts and others

Figure 1.1: Primary Energy Consumed in Office Building

(Source: Wee, 2003; Bateni, 2004; Malaysia Energy Centre, 2004; Yusofand Mustapa,

2005)

As shown in Figure 1.1, air conditioning system accounts for 52 percent of energy

consumed in office building. Advance researches have been conducted to increase the

efficiency of the air conditioning system. However, the efforts are not sufficient if the

source for high energy usage of the air conditioning system is not treated, which in this

case is uncontrollable heat gain from glazing area . . Therefore an energy conservation

strategy by addressing the stated problem is discussed in this study.

In Malaysia, the necessity of implementing an energy conservation programme

had been recognized from earlier five year period. In the Ninth Malaysia Plan, the

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PII~at Khidmat MakJumal Akademik UNlVERSITI MALAY IA SARAWAK

government encourages the efficient usage of energy as it moderates the impact of

escalating fossil fuel on the economy and the environment.

1.3 Energy Production

The electricity supply industry in Malaysia was privati sed in 1990. There are

three main utilities in the country namely Tenaga Nasional Berhad (TNB), Sarawak

Electricity Supply Corporation (SESCo) and Sabah Electricity Sdn. Bhd. (SESB). The

power demand in 2006 was 14,557 MW, met by total generation capacity of 19,998 MW

(Malaysia Energy Commission, 2006)

Power producers in Malaysia used as much as. 70.2 percent of natural gas, 21.8

percent of coal, 2.2 percent of crude oil, 5.5 percent of hydro and 0.3 percent of other mix

such as biomass to generate electricity in 2005. However, the dependency on natural gas

in the generation mix is promised to be reduced in Malaysia Ninth Plan when the source

of fuel is further diversified with the increased used of coal. Table 1.1 presents the fuel

mix generation in Malaysia according to the ninth plan.

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Table 1.1: Fuel Mix in Electricity Generation, 2000-20 I 0

Year Oil Coal Gas I

Hydro Others Total

% of Total (GWh)

Total

Malaysia

2000 4.2 8.8 77.0 10.0 0.0 69280

2005 2.2 21.8 70.2 5.5 0.3 94299

2010 0.2 36.5 55.9 5.6 1.8 137909 I

Peninsula

(TNB)

2000 2.3 8.7 79.6 9.4 0.0 63634

2005 0.5 22.5 71.9 4.9 0.2 86242

2010 0.1 38.1 56.8 3.4 1.6 1267 18

Sabah

(SESB)

2000 47.3 - 31.4 21.3 - 2299

2005 42.6 - 43.0 13.6 0.8 3447

2010 0.5 18.5 47.2 26.5 7.3 4808

Sarawak

SESCO)

2000 11.2 15.1 59.4 14.3 - 3347

2005 4.7 25.0 I 58.9 11.4 - 4610

2010 3.0 21.2 44.1 31.7 - 6383

(Source: Malaysia Ninth Plan)

Although electricity is a clean energy at the point of use and the main driver of

economical activity in this country, the process of generating electricity by burning fossil

fuel however emits carbon dioxide and other pollutants to atmosphere that cause

environmental issues.

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1.4 Environmental Issues

Energy production and consumption places undeniable pressure on the

environment. Over the past 20 years, fossil fuel burning has produced approximately one

third of the increase in carbon dioxide from human activity (Pearson and Palmer, 2008).

Electricity sector in Malaysia is projected to produce 49 percent of carbon dioxide

emission for next 20 years followed by the transportation sector at 28 percent and

industry sector at 20 percent (APEC Outlook, 2006).

Damage to natural ecosystems and climatic changes are the current environmental

issues due high percentage of carbon dioxide in the atmosphere. Growing concern on the

rising amount of carbon dioxide in atmosphere has led to Kyoto Protocol in 1997 and has

entered into force in 2005. It ratifies by 178 countries and government entities including

Malaysia. Countries that ratify this protocol commit to reducing their emissions ofcarbon

dioxide and other greenhouse gases (GHG) such as methane, nitrous oxide,

hydrotlourocarbons and perfluorocarbons, or engaging in emissions trading if they

maintain or increase emissions of these green house gases.

Other environmental pressures from energy production and consumption include

wastes water contamination from mining, oil spills and discharges to marine waters, soil

damage from spills and leakages of liquid fuels, and impacts on ecosystems from the

construction and operation of large dams.

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Thus, improving energy efficiency in a building will lead to double benefits to

reduce emissions of greenhouse gases (GHGs) and pollutants by reducing the

conswnption of fossil fuels and also the amount of energy consumed.

1.5 Aim and Objectives of Study

This research aims to evaluate the effectiveness of internal shading devices in the

reduction of energy consumption in an office building. Such an evaluation allows the

quantification of the energy saving that can be obtained by reducing the cooling load in

the building. To achieve the aims of the study, specific objectives are defined as listed

below:

a) To investigate the contribution of envelope thermal heat gain to energy

consumption of the office buildings.

b) To select and appropriately calibrate building simulation model in EnergyPlus

thus validate the EnergyPlus as reliable tool to predict the energy consumption

of buildings.

c) To determine the type of internal shading that provides the optimum energy

consumption in office building.

d) To investigate the distance of internal shading devices to window glass that

provides the optimum energy consumption.

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I e) To investigate the impact of internal shading devices on day lighting as a

function to provide energy saving opportunities.

1.6 Structure of the Thesis

The thesis is presented in six chapters covering the background information,

literature review, field measurement, validation of the model based on actual office

building, simulation the proposed energy conservation strategies and finally, the

conclusions and recommendations.

Chapter 1 has presented the brief introduction to the problem under investigation

and stated the aim and objectives of the work.

Chapter 2 discusses the literature review of the factors affecting energy

consumption in a building and human comfort, and the related previous study on energy

simulation programme, Energy Plus.

Chapter 3 describes the methodology on co·nducting field measurement and

creating evaluation model to further investigate energy conservation strategies.

Chapter 4 presents the field measurement results for energy saving opportunities

and validating building energy programme, EnergyPlus.

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Chapter 5 evaluates the potential of internal shading devices for energy saving in

an office building. This chapter presents the simulation results and discusses energy

consumption of the office room when various parameters of internal shading devices

were tested.

Chapter 6 summarizes the research results and provides recommendations for

possible future work.

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