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Environmental Performance Analysis of a Single Family House in Florida

Permanent Link: http://ufdc.ufl.edu/UFE0041651/00001

Material Information

Title: Environmental Performance Analysis of a Single Family House in Florida
Physical Description: 1 online resource (77 p.)
Language: english
Creator: Raheem, Adeeba
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: co2, designbuilder, doe, eia, energy, envelope, residential, simulation
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Master of Science in Building Construction ENVIRONMENTAL PERFORMANCE ANALYSIS OF A SINGLE FAMILY HOUSE IN FLORIDA Chair: R. Raymond Issa Cochair: Svetlana Olbina Major: Building Construction Energy consumption and greenhouse gas emissions are major indicators of environmental performance of any building. In the recent years, the need for much-improved energy efficient performance in the housing sector has substantially grown due to serious energy concerns in the United States. According to the World Business Council for Sustainable Development, energy use for buildings in the Unites States is appreciably higher than in other regions, and this is likely to continue. The lack of a structured approach to planned use of the sustainability features like post occupancy evaluation, benchmarking against similar projects, or setting performance targets has made the situation grimmer. In 2005, approximately 72% of all households were single family residences in the United States and had an average EUI (End-Use-Intensity) of 52.9 thousand Btu per square foot. This indicates a significant impact of the energy used in these units on overall US consumption. Environmental performance analysis involves calculation and evaluation of energy consumption, CO2 generation and determination of acceptable levels of comfort and other occupancy requirements. For the past 50 years, a wide variety of building energy simulation programs have been developed, improved and are in use throughout the building energy community. With the advancement in simulation technology, the environmental performance can be assessed before the actual construction of the building. The primary goal of this research was to analyze annual energy consumption and CO2 emissions in a single family house in Florida occupied by a defined type of household using the Design Builder software. The secondary goal was To compare the results with the EIA data published in the Building Energy Data book (DOE 2009) for validation purposes and To establish the importance of simulation technology through recommended metrics after the assessment of environmental performance of a typical single family house in Florida. This research has shown that computer-aided building simulation is really important in the study of energy performance, design and the operation of the buildings. The implementation of the modern simulation technology at the design stage of the dwellings can help in decision making process for standards compliance and economic optimization.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Adeeba Raheem.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2010.
Local: Adviser: Issa, R. Raymond.
Local: Co-adviser: Olbina, Svetlana.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-04-30

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041651:00001

Permanent Link: http://ufdc.ufl.edu/UFE0041651/00001

Material Information

Title: Environmental Performance Analysis of a Single Family House in Florida
Physical Description: 1 online resource (77 p.)
Language: english
Creator: Raheem, Adeeba
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: co2, designbuilder, doe, eia, energy, envelope, residential, simulation
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Master of Science in Building Construction ENVIRONMENTAL PERFORMANCE ANALYSIS OF A SINGLE FAMILY HOUSE IN FLORIDA Chair: R. Raymond Issa Cochair: Svetlana Olbina Major: Building Construction Energy consumption and greenhouse gas emissions are major indicators of environmental performance of any building. In the recent years, the need for much-improved energy efficient performance in the housing sector has substantially grown due to serious energy concerns in the United States. According to the World Business Council for Sustainable Development, energy use for buildings in the Unites States is appreciably higher than in other regions, and this is likely to continue. The lack of a structured approach to planned use of the sustainability features like post occupancy evaluation, benchmarking against similar projects, or setting performance targets has made the situation grimmer. In 2005, approximately 72% of all households were single family residences in the United States and had an average EUI (End-Use-Intensity) of 52.9 thousand Btu per square foot. This indicates a significant impact of the energy used in these units on overall US consumption. Environmental performance analysis involves calculation and evaluation of energy consumption, CO2 generation and determination of acceptable levels of comfort and other occupancy requirements. For the past 50 years, a wide variety of building energy simulation programs have been developed, improved and are in use throughout the building energy community. With the advancement in simulation technology, the environmental performance can be assessed before the actual construction of the building. The primary goal of this research was to analyze annual energy consumption and CO2 emissions in a single family house in Florida occupied by a defined type of household using the Design Builder software. The secondary goal was To compare the results with the EIA data published in the Building Energy Data book (DOE 2009) for validation purposes and To establish the importance of simulation technology through recommended metrics after the assessment of environmental performance of a typical single family house in Florida. This research has shown that computer-aided building simulation is really important in the study of energy performance, design and the operation of the buildings. The implementation of the modern simulation technology at the design stage of the dwellings can help in decision making process for standards compliance and economic optimization.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Adeeba Raheem.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2010.
Local: Adviser: Issa, R. Raymond.
Local: Co-adviser: Olbina, Svetlana.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-04-30

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041651:00001


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ENVIRONMENTAL PERFORMANCE ANALYSIS OF A SINGLE FAMILY HOUSE IN FLORIDA By ADEEBA ABDUL RAHEEM A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2010 1

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2010 Adeeba Abdul Raheem 2

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To my parents, husband and son 3

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ACKNOWLEDGMENTS First of all, I would like to thank Almighty Allah the Beneficent and Merciful of all. I would like to pay my sincere gratitude to Dr. Raymond Issa who remained a persistent source of guidance and support not only for the completion of my thes is but also during my stay at Rinker School. I really appreciate for the time and efforts Dr. Svetlana Olbina gave me throughout my research and really inspir ed me for further research in this area. I gratefully acknowledge Dr. E. Douglas Lucas for his involvement with his originality that has triggered and nourished my intellectual maturity ri ght from the start of my masters degree and it will be beneficia l for me in the future too. I offer my regards to all those who support ed me in any respect for the successful completion of my thesis. I specially want to mention inseparable support and prayers of my parents that always made me feel a bless ed person. Last but not the least I express my appreciation in true means to my husband whose continuous support, encouragement and help from the preliminary stage to the c oncluding level enabled me to accomplish my research successfully. 4

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TABLE OF CONTENTS page ACKNOWLEDGMENTS ..................................................................................................4 LIST OF TABLES ............................................................................................................7 LIST OF FIGURES ..........................................................................................................8 LIST OF ABBREVIATIONS ...........................................................................................10 ABSTRACT CHAPTER 1 INTRODUCTION ....................................................................................................14 Background .............................................................................................................14 Problem Statement .................................................................................................16 Research Objectives ...............................................................................................19 Scope and Limitations .............................................................................................20 Organization of the Study .......................................................................................20 2 LITERATURE REVIEW ..........................................................................................22 Introduction .............................................................................................................22 Components of Energy Use in a House ..................................................................25 Residential Energy Consumption in Florida ............................................................29 Energy Simulation Technology ...............................................................................31 DesignBuilder Energy Simulation Software ......................................................32 Main Features ............................................................................................33 Major Uses .................................................................................................33 Model Hierarchy .........................................................................................34 3 RESEARCH METHODOLOGY ...............................................................................35 Basic Modeling Data ...............................................................................................35 Simulation Input Data ..............................................................................................36 Location and Climate ........................................................................................36 Structure ...........................................................................................................37 A.Wall construction .................................................................................37 B.Roof ....................................................................................................38 C.Floors ..................................................................................................38 Lighting .............................................................................................................38 Openings ..........................................................................................................39 Heating and Cooling .........................................................................................39 Occupancy .......................................................................................................39 5

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4 RESULTS ...............................................................................................................41 Model Design ..........................................................................................................41 Environmental Performance Analysis .....................................................................42 Annual Energy Consumption ............................................................................42 Internal Gains .............................................................................................42 Envelope Heat Gains and Losses ..............................................................42 Annual Fuel Consumption ................................................................................44 Fuel Breakdown .........................................................................................44 Total Fuel Consumption .............................................................................45 Annual CO2 Production ....................................................................................45 Validity of the Design Builder Results .....................................................................46 Recommendation Metrics .......................................................................................49 5 CONCLUSIONS .....................................................................................................59 APPENDIX A DRAWINGS FOR BASE MODEL HO USE..............................................................62 Plans .......................................................................................................................62 Ground Floor Plan ............................................................................................62 First Floor Plan .................................................................................................63 Axonometric Views .................................................................................................64 Elevations ...............................................................................................................66 South Elevation ................................................................................................66 West Elevation .................................................................................................67 B TABLES FOR ANALYS IS RESU LTS.....................................................................68 C LIST OF USEF UL WEBSI TES................................................................................70 U.S. Agencies and National Organizations .............................................................70 State Agencies and Organizations ..........................................................................70 D VALIDITY DATA .....................................................................................................72 LIST OF REFERENCES ...............................................................................................75 BIOGRAPHICAL SKETCH ............................................................................................77 6

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LIST OF TABLES Table page 2-1 Components of energy use in dwellings .............................................................26 3-1 Characteristics of a typi cal single family unit (EIA 2008) ....................................36 3-2 Data input for location and climate .....................................................................37 4-1 Reduction in energy consumption by reducing infiltration ...................................51 4-2 Savings by reducing infiltration ...........................................................................52 4-3 Savings by changing glass type .........................................................................54 4-4 Percentage increase in energy c onsumption by mechanical ventilation .............55 4-5 Reduction in energy consumption due to lighting control ...................................56 4-6 Recommendation metrics ...................................................................................58 7

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LIST OF FIGURES Figure page 1-1 Major factors effecting envir onmental performance of a building. .......................14 1-2 Major drivers for energy performance of a building. ...........................................15 1-3 Median size of new single family homes (Source: NAHB 2007). ........................17 1-4 Average area per person in a new U. S. single-family house (Source: NAHB 2007). .................................................................................................................18 2-1 Building energy projection by region 2003/2030 (Source: US EIA 2006). .......23 2-2 Geographic location of U.S. households (Source: EIA 2000). ............................24 2-3 U.S. housing stock (Source: Building Energy data book 2009). .........................24 2-4 Energy use in different types of homes in U.S. (Source: EIA 2005). ..................25 2-5 New homes with central air conditioner installed (1973-2005). ..........................27 2-6 Air conditioning saturation by region 1978-2005. ................................................28 2-7 Residential primary energy consum ption in U.S. (Source: U.S. DOE 2009). ......29 2-8 Per Capita residential consumption of electricity in top thr ee states of U.S. (Source: EIA 2007). ............................................................................................30 2-9 Typical Florida daily electric load shapes (Source: FPSC 2009). .......................31 3-1 Horizontal cross section of the wall (Not to scale). .............................................37 3-2 Horizontal cross section of Interior wall (Not to scale). .......................................38 3-3 Vertical cross section of the roof (Not to scale). .................................................38 4-1 Axonometric views of the base model house. ....................................................41 4-2 Internal heat gains. A) Annual internal gains. B) Monthly internal gains breakdown. .........................................................................................................42 4-3 Energy consumption through envelope of the house. A) Annual energy consumption. B) Monthly ener gy consumption breakdown ...............................43 8

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4-4 Residential Fuel consumption. A) A nnual fuel consumption. B) Monthly fuel breakdown. .........................................................................................................44 4-5 Total fuel usage. A) Annual total fuel usage. B) Monthly breakdown of total fuel usage. ..........................................................................................................45 4-6 CO2 emissions. A) Annual CO2 emissions. B) Monthly breakdown of CO2. emissions. ..........................................................................................................46 4-7 Comparison of Design Builder results and EIA data. ...........................................47 4-8 Comparison of annual energy expenditure. ........................................................48 4-9 Comparison of CO2 emissions results. ...............................................................49 4-10 Energy saving by controlling infiltration ..............................................................51 4-11 Dollar saving by controlling infiltration ................................................................52 4-12 Energy saved by glass type. ...............................................................................53 4-13 Energy saved by ventilation type. .......................................................................55 4-14 Energy savings by lighting control. .....................................................................56 9

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LIST OF ABBREVIATIONS ASHRAE American Society of Heati ng, Refrigerating and Air-Conditioning Engineers COP Co efficient of performance (dimensionless, heating/cooling capacity: (Btu) over electric input (Btu)) CO 2 Carbon dioxide (CO 2 ) Conduction the transfe r of thermal energy CFD Computational fluid dynamics CAD Computer Aided Design Delivered Energy The energy consumed by an end-user on site, not including electricity generation and transmission losses DOE Department of Energy EIA U.S. Energy Information Administration EPA U.S. Environment al Protection Agency EUI End use Intensity FPSC Florida Public Service Commission gbXML Green Building XML schema HVAC Heating, ventilating, and air-conditioning IEA International Energy Agency IECC International Energy Conservation Code KBTU Kilo BTU (10^3 BTU) Lbs Pounds NAHB National Association of Home Builders OpenGL Open Graphics Library 10

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Primary Refers to energy used at the source (includi ng fuel input to electric power plants) Quads Quadrillion (10^15 BTU) R-value Thermal resistance measured in (Btu/Hr-SFo F) -1 SHGC Solar heat gain coefficient RECS EIA's Residential Energy Consumption Survey WBCSD World Business Council for Sustainable Development WRI World Resources Institute 11

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Abstract of Thesis Pres ented to the Graduate School of the University of Florida in Partial Fulf illment of the Requirements for the Ma ster of Science in Building Construction ENVIRONMENTAL PERFORMANCE ANALYSIS OF A SINGLE FAMILY HOUSE IN FLORIDA By Adeeba Abdul Raheem May 2010 Chair: R. Raymond Issa Cochair: Svetlana Olbina Major: Building Construction Energy consumption and greenhouse gas emissions are major indicators of environmental performance of any building. In the recent years, the need for muchimproved energy efficient performance in t he housing sector has substantially grown due to serious energy concerns in the Unit ed States. According to the World Business Council for Sustainable Development, energy use for buildings in the Unites States is appreciably higher than in other regions, and this is likely to continue. The lack of a structured approach to planned us e of the sustainability features like post occupancy evaluation, benchmarking against similar projects, or setting performance targets has made the situation grimmer. In 2005, approximately 72% of all households were single family residences in the United States and had an average EUI (End-Use-Intensity) of 52.9 thousand Btu per square foot. This indi cates a significant impact of the energy used in these units on overall U.S. consumption. Environmental performance analysis involves calculation and evaluation of energy consumption, CO 2 emissions and determination of a cceptable levels of comfort and other occupancy requirements. For the past 50 years, a wide variety of building energy 12

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simulation programs have been developed, improved and are in use throughout the building energy community. With the adv ancement in simulation technology, the environmental performance can be assessed bef ore the actual construction of the building. The primary goal of this resear ch was to analyze annual energy consumption and CO 2 emissions in a single family house in Florida occupied by a defined type of household using the Desi gn Builder software. T he secondary goal was To compare the results with the EIA data published in the Building Energy Data book (DOE 2009) for validation purposes and To establish the importance of simulation technology through recommended metrics after the assessment of environm ental performance of a typical single family house in Florida. This research has shown that compute r-aided building simulation is really important in the study of energy performance, design and t he operation of the buildings. The implementation of the modern simulation technology at the design stage of the dwellings can help in decis ion making process for standards compliance and economic optimization. 13

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CHAPTER 1 INTRODUCTION Background Environmental performance of buildings depends on many factors. Energy consumption and CO 2 are the major concerns in the re cent times especially with the spread of the sustainable design and green buildings concepts throughout the world (Figure 1-1). Under the 1997 Montreal Pr otocol, governments agreed to phase out chemicals used as refrigerants that have the potential to destroy stratospheric ozone. It was therefore considered desirable to reduce energy consumption and decrease the rate of depletion of world energy reserv es and pollution of the environment (Omer 2009). Primary energy Renewable energy NOx SO2 CO2 Major factors for environmental performance Figure 1-1. Major factors effecting environmental performance of a building. 14

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So for reducing the energy consumption and CO 2 emissions, it is really important to design buildings that are mo re efficient in their use of energy for heati ng, lighting, cooling, ventilation, and hot water supply. Energy performance in buildings varies according to geography, climate, building type and location (Figure 1-2). In the co ming years, climate change will increase demand for more energy efficient structures as people seek to maintain comfort levels in more extreme conditions. T he other main drivers are: Demographics Economic development Lifestyle changes Depletion of energy resources(non-renewable) Technology and the spread of new equipment Economic Develo p ment Demographics Lifestyles Spread of tec hnol og y Climate Geograph y Building t yp e Location Figure 1-2. Major drivers for energy performance of a building. According to the U.S. Department of Energy (DOE), the residential sector consumed 10.8 Quads of delivered energy and th is does not include energy lost during 15

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production, transmission and distribution to the consumers. Moreover in residential buildings alone, 1192 million metric tons of CO 2 emissions were recorded in 2006. Between 1990 and 2008, total residential CO 2 emissions increased by 27.5% while population increased by only 22%. Also U.S. buildings emissions approximately equal the combined CO 2 of Japan, France and the Un ited Kingdom (EIA 2008). In 2007, approximately 1,219,000 new single family housing units were built in United States and per household energy expenditure was increased about 12% from the averaged national amount of 2005 ($1873). This trend thus indicates that construction of single family units is on t he rise and in the future it will have a huge impact on the overall energy consumption in the US. Such ever-increasing demand could place significant strain on the current energy infrastructure and potentially damage world environmental health by CO, CO 2 SO 2 and NO x effluent gas emissions and global warming. Problem Statement A majority of Americans live in singlefamily houses. In 2007, 65% of the 111 million U.S. households were single-family (N AHB 2007). The size of single family houses has increased steadily over the past decade in U.S. Between 2004 and 2005, median square footage increased from 2,140 square feet to 2, 227 square feet nationally (Figure 1-3), and increased in all four of t he principal census regions as well. In 2007 average square footage of single family house was about 2,479 square feet that was a 152% increase from 1950 (983ft 2 ). Average number of occ upants per U.S. household in 1950 was 3.37 and in 2000 it was 2.62 which is a decrease of 22% from 1950. Also in 1950, 9% of housing units were occupied by only one person. By 2006, this increased to 27% (NAHB 2007). 16

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Figure 1-3. Median size of new singl e family homes (Source: NAHB 2007). As house size increases, so do the env ironmental impacts associated with buildings and development. With this resour ce consumption also increases, the land area affected by development grows, stor m water runoff increases as impermeable surface area increases, and energy use rises. Total U.S. residential energy consumpti on rose approximately 13% over the past quarter century. There is a significant in crease in the number of homes with clothes washers, dryers, and dishwashers. Addition ally, a growing number of U.S. households now have multiple televisions, computers, and refrigerators (E IA 2005). The average area per person in a new U.S. singlefa mily house has increased about 188% from 1950 (Figure 1-4) (Wilson 2005). About half the units in the Midwest, South and West regions had two or more stories. Increas ed areas and volumes mean bigger footprints and also greater energy consumption and CO 2 emissions. 17

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Figure 1-4. Average area per person in a new U.S. single-family house (Source: NAHB 2007). Other trends in American si ngle-family housing have been similar. In 1967, for example, 48% of new single-family houses had garages for two or more cars; by 2002, that figure had jumped to 82%. In 1975, 20% of new single-family houses had 2.5 or more bathrooms; by 2002, that fi gure had increased to 55% (Wilson 2005). Thus the current energy intensive conditi on of U.S. residentia l market cannot be neglected and should be addressed systematica lly. The best way is to incorporate energy analysis in the design phase wher e one can plan and choose that type of components that save energy bef ore actual construction and thus save lot of money for the tenants over the life cycle of the bui lding and ultimately reduces energy consumption for the whole country. This multiple-view assessment of energy performance at the design stage is theref ore essential in order to prevent the delivery of 18

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the facility that does not comp ly with modern energy constraint s. Also with the improved simulation technologies, it is going to be much easier for construction professionals to improve the design techniques for more energy efficient residences and also to control CO 2 emissions during construction and use as well. Research Objectives The residential sector consumed 20% (20. 79 Quads) of U.S. primary energy in 2006 (U.S. DOE 2009). Electricit y made up the overwhelming ma jority of consumption, representing 70% of all prim ary energy used in the re sidential sector. In 2007, about 632,000 single family units were completed in the southern region which accounts for 52% of the total units built in U.S. t hat year. Energy performance of commercial buildings is mostly taken care of but t he housing sector also has a huge post occupancy impact on the overall energy statistics. The pr imary objective of this research is to analyze post occupancy energy performance of a single family house in the hot and humid climate of Florida by cons idering the follo wing factors: Energy consumption CO 2 generation Fuel usage breakdown The results will be compared to EIA (2005) data for validity purposes and based on the information from these results, a recomm endation metrics will be developed for building more energy efficient houses. The secondary goal of this thesis is to disseminate information about a recently available and user friendly energy analysi s software (Design Builder) which can be really helpful for construction professional an d designers to make decisions at the early stage of design. 19

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Scope and Limitations The scope of the study is limited to expl ore two major factors of environmental performance i.e. energy consumption and CO 2 emissions. Detailed analysis is done to collect important statistical data for energy consumption and CO 2 emissions in a typical single family house in Gainesville, FL fo llowed by parametric study to deduce some useful results. This study is intend ed to perform post occupancy environmental performance analysis for a two stor ey single family house in Gainesville, FL. Energy use during occupancy far exceeds (by approximatel y 85%) that in any other phase in the buildings so life cycle perspective of energy used in manufacturing or producing materials and building the house is not taken in to account in this study. Design builder energy analysis software is used as a modeling as well as simulation tool for the base model house in Gainesville, FL. Organization of the study Chapter 2 will explore the majo r factors review literature related to national energy consumption data for single family houses and compare it with t he specific data for Florida region. This will help to establish t he need to give particular attention for energy efficient housing design. This chapter also br iefly gives the description of Design Build software as a most recent development in energy simulation world. Chapter 3 is a description of the methodology us ed that is the backbone of this thesis. This put a real emphasis on incorporating modern simulation technology at the design stage. Chapter 4 is divided in three sections. The first secti on presents the results of the simulation for annual energy consumption and CO 2 consumption in the base model house for Gainesville, FL. The second section includes validation of thes e results from EIA published data. The third section consists of comparative recommendations obtained 20

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from the results after modi fying the base model house. The house was modified based on the most important factor s observed during analysis. Final ly, Chapter 5 consists of conclusions made after the environmental performance analysis of the base model house in Gainesville, FL. 21

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CHAPTER 2 LITERATURE REVIEW Introduction Any building project begins with a consideration of the various performance objectives of interest to building stakehol ders (e.g., owners, designers, operators, occupants, etc.). While primary attention is generally given to space requirements and construction costs, a wide spec trum of objectives may be at least informally considered at this stage, including: energy-efficien cy; environmental impac t; life-cycle economics; occupant health, comfort and productivity; and building functionality, adaptability, durability, and sustainability (Robert et al. 2002). A rapidly growing demand for better energy performance in buildings is leading to an ongoing development of strategies and tec hnologies to improve energy efficiency in construction without compromising on comfor t, cost, aesthetics and other performance considerations. The focus of the world's a ttention on environmental issues in recent years has stimulated responses in many countries which have led to a closer examination of energy conserva tion strategies for conventi onal fossil fuels. Buildings are important consumers of energy and thus important contributors to emissions of greenhouse gases into the global atmosphere (Pitts 1994). For the past 40 years, due to low energy pr ices in the United States, there was little concern for energy-efficient design of bui ldings. With the oil shocks of the 70s, an increased awareness of energy and the environment led to greater interest and research in the use of energy in bu ildings and its environmental consequences (Diamond 2001). Due to worldwide advancement in technology, the occupants preferences for achieving comfort level in side the house has been changed but energy 22

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use for buildings in the United States is still substantially higher than in the other regions, and this will likely continue into the foreseeable future unless changes are made in the way of building houses (WBCSD 2003). Figure 2-1 shows that in 2030, U.S. is pr ojected to be the largest consumer of energy both in residential and commercial sect ors. It also shows that the residential sector consumes a larger part of the energy than the commercial se ctor at the present time and this trend will continue into the future. Figure 2-1. Building energy projection by region 2003/2030 (Source: US EIA 2006). Over the 19 years since the first RECS in 1978, the number of households in the United States has increased by 33% from 76.6 million to 101.5 million in 1997. While each of the four main Census regions has sh ared in this growth, the rate has differed from region to region. The la rgest increases were in t he West and South, where the number of households grew by 56% and 46% re spectively. In the Northeast the number grew by 13% and in the Midwest by 17% (Figure 2-2) 23

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Figure 2-2. Geographic location of U.S. households (Source: EIA 2000). The mix of housing types in the U.S. housi ng stock has remained fairly constant in the past and that trend is likely to continue into the future. In 2005, approximately 72% of all households were single family residenc es, 22% were multifamily residences and the remaining 6% were mobile homes (Figure 2-3). Figure 2-3. U.S. housing stock (Source: Building Energy data book 2009). About 80% of residential energy use is c onsumed in single-family homes, while 15% is consumed in multi-family dwellings such as apartments, and 5% is consumed in 24

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mobile homes (Figure 2-4) Approximately 84% of si ngle-family homes have air conditioning (central system, wall/window units, or both), 95% have a clothes washer, 92% have a clothes dryer and 74% have a personal computer. So the changed living standards have significantly increased the energy demand in single family houses over the past few years. Figure 2-4. Energy use in different ty pes of homes in U.S. (Source: EIA 2005). Components of Energy use in a house Post occupancy energy consumption in a ho use consists of many components but broadly can be divided into f our categories (Sheridan 2009): Heat gains to dwelling (Cooling loads) The way the dwelling is used: Energy consumption can vary dramatically among households, even when the households have similar physical characteristics. Occupant behavior has a major impact on building energy consumption, suggesting that interventions to modify occupant behavior could result in appreciable energy savings (Roth 2008). 25

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Internal and external environment Heat losses from the dwelling (Heating loads) Table 2-1. Components of energy use in dwellings Heat gains to dwelling Way the dwelling is used Internal and external environment Heat loss from the dwelling Heating system fuel, efficiency ,controls Water heating Cooking Use of appliances Solar gains through windows Gains from occupants Heat gains from lighting Gains from the envelope Number of occupants Household type Employment status Income Occupants preferences for internal temperatures Use of heating, ventilation and other appliances Internal temperatures External temperatures Solar radiation Wind speed Sheltering Atmospheric pressure Conduction heat loss through plane areas Conduction heat loss through joints and thermal bridges Heat loss due to designed ventilation Heat loss due to undersigned infiltration Heat losses from floors The major portion of post occupancy energy is used for the provision of heating, cooling and lighting. In the last decade cooling techniques have been drastically changed from natural ventilation to air-conditi oning units and then to centralized cooling systems in the residential se ctor of the U.S. More Americans have air-conditioning and are using their air-conditioning equipment mo re often. The percent of Americans with central air-conditioning has increased while the percent with window/wall units has dropped. Central air conditioning has been a standard feature of th e southern region, 26

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where almost all single family housing units hav e central AC installed, but now it seems to be a standard feature nationwide as 90% of all units completed in 2005 had central air conditioning (Figure 2-5). The share of homes with central air conditioning has increased from 46% in 1975 to 70% in 1985, 80% in 1995, and 90% in 2005 (NAHB 2006). Figure 2-5. New homes with central air conditioner installed (1973-2005). All areas of the United States show a significant increase in air-conditioning equipment and use in recent years (Figure 26). The share of homes with central air conditioning in 2005 was highest in the southern region (100%) followed by the Midwest (92%), Northeast (79%) and West (63%). These trends indicate that there continues to be an increase in demand for air-conditionin g and that the market is significantly influenced by a concern for energy and the environment. Advancements in technology are responding to those concerns. 27

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Figure 2-6. Air conditioning saturation by region 1978-2005. Energy consumption in homes derives pr imarily from two s ources in the U.S: natural gas and electricity. Nationwide, 58% of the approximat ely 110 million U.S. households heat with natural gas because it is historically the cheapest fuel for home heating. For these homes, natural gas is used for space heating and domestic hot water, and electricity is used for appliances and air conditioning. Electricity demand is increasing with changing life styles in the society and is expected to rise above 15 Quadrillion BTU in 201 1 (Figure 2-7). Heating and cooling systems in the U.S. together emit 150 million tons of CO 2 into the atmosphere each year, adding to global climate change. They also generate about 12% of the nations sulfur di oxide and 4% of the nitrogen oxides, the chief ingredients in acid rain (U.S. DOE 2009). 28

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1980199020002010202020308.35 8.95 10.45 11.64 13.32 14.61 15.25 15.2 15.92 16.55 17.33Quadrillion BTU YearsResidential Primay Energy Consumption Electricity Coal Natural gas Petroleum Renewable Figure 2-7. Residential prim ary energy consumption in U.S. (Source: U.S. DOE 2009). Residential Energy consumption in Florida Floridas per capita residential electricity demand is among the highest in the country, due in part to high ai r-conditioning use during the hot summer months and the widespread use of electricity for home heating during the winter months. In 2006, Florida residential energy consumption was 767.6 trillion Btu that wa s almost doubled at the end of 2007 (Figure 2-8). Energy consumed for space heating is 5 million Btu per household and average amount spent for space heating is $83 per household. Electricity consumed for air conditioning is 13 million Btu per househo ld and average amount spent for air conditioning is $322 per household (RECS 1997).With the curr ent domestic energy consumption scenario, this expenditure will likely increase in the future. 29

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767.6 867.5 1140.5 1339.5 1535.2 1594.1Per Capita ResidentialEnergyConsumption (Trillion BTU) 2006 2007 Figure 2-8. Per Capita resident ial consumption of el ectricity in top thr ee states of U.S. (Source: EIA 2007). Because of rapid population growth, unique climatic conditions, and the continuous rise in the standard of living, the trends in national energy consumption have been extreme in Florida. Aside from the rapid growth, the most striking change in the residential sector was in the ty pes of fuels used. This fuel switching was due in part to the added convenience of electricity for dom estic uses and the steady increase in reverse cycle air conditioning units in new construction (Milon 1991). Floridas traditionally high temperatures and humid climate have a profound effect on residential customers electrical energy usage. Typically, residential customers electrical usage varies more throughout the day than commercial usage and shows more pronounced peaks in the early evening in the summer and in the mid-morning and late evening in the winter (F igure 2-9). Industrial electric al energy usage, however, is more uniform throughout the day (FPSC 2009). 30

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Figure 2-9. Typical Florida daily el ectric load shapes (Source: FPSC 2009). The high proportion of residential customers in Florida results in more pronounced summer and winter peak demands than in a stat e with a higher proportion of industrial customers. In the summer, customer demand begins to climb in the morning and peaks in the early evening, a pattern which corre sponds to the sun heating buildings and the resulting air conditioning loads. In contrast the winter load curve has two peaks, the largest in mid-morning, followed by a smalle r peak in the late evening. Both correspond to heating loads (Figure 2-9). Energy Simulation Technology Technical developments and a sudden ex plosion of available construction materials during the 20 th century have rolled back the lim its of architec ts imagination and they have now the ability to develop al most any imaginable concept. To meet the expectations of modern architecture and changing habits towards the use of energy, 31

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researchers have to develop specific solutions. However the development of communication and information te chnologies led to a growi ng awareness of the benefits that could be obtained if isolated programs had the possibi lity to model, communicate and exchange information with the other si mulation programs (Laptali et al. 1997). Over the past 50 years, literally hundreds of building energy programs have been developed, enhanced and are in use. The core t ools in the building energy field are the whole-building energy simula tion programs, which provi de users with key building performance indicators such as energy use and demand, temperat ure, humidity, and costs (Crawley et al. 2008). As performance issues like comfort and energy become increasingly important, the capabilities of building simulation are increasingly in demand to provide information for decision-making dur ing the building design process. This need has started the development of design advice tools where the common objective is to facilitate the use of building simulation in the design process (Petersen et al. 2010). Barriers to the sharing and exchange of building data between computer simulation applications had to be removed no w through the development of simplified simulation software packages like Design Builder that is user-friendly, accurate and can be really helpful to improve energy perform ance of buildings through a multiple-view assessments during the design phase. This is to ensure a construction that meets with modern users acceptance and still can save a lot of energy. DesignBuilder Energy Simulation Software Design Builder is a state-of-the-art software tool for calculating building energy consumption, CO 2 lighting and comfort performance. De sign Builder allows comparison of the function and performance of building designs (Tindale 2004). 32

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Main Features Design Builder is the first comprehensiv e user interface to the Energy Plus dynamic thermal simulation engine which help s to model and simulate the building in a single application. It saves time and limit num ber of error which was a big problem while importing between different simulation software packages. Other major features include: It can import 3-D CAD models from Arch iCAD, Microstation, Revit and any other CAD software supporting the gbXML standard Design Builder is an easy-to-use OpenG L solid modeler, which allows building models to be assembled by positioning, stretching and cutting 'blocks' in 3-D space. DesignBuilder has built-in features to facilitate energy per formance comparisons. The parametric analysis facility allows the inve stigation of the effect of variations in design parameters on a r ange of performance criteria. Design Builder has easy to use CFD f unctionality integrated with the simulation model and optionally uses EnergyPl us outputs to define CFD boundary conditions. ASHRAE worldwide design weather data and locations (4429 data sets) are included with the software and more t han 2100 EnergyPlus hourly weather files are automatically down loaded as required. Major uses Design Builder is a simulation tool whic h offers flexible geometry input and extensive material libraries and load prof iles. EnergyPlus is integrated within DesignBuilders environment which allows carrying out complete simulations without leaving the interface (Ibarra 2009). Some of the major uses of Design Builder are as follows: Building energy simulation Evaluation a range of faade options for the effect on overheating, energy use and visual appearance. Evaluate optimal use of natural light by modeling lighting control systems and 33

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calculating savings in electric lighting. Calculation of temperature, velocity and pressure distribution in and around buildings using CFD Visualization of site layouts and solar shading Thermal simulation of naturally ventilated buildings HVAC design including heati ng and cooling equipment sizing Communication aid at design meetings Model Hierarchy DesignBuilder follows a model data hier archy. DesignBuilder further uses data inheritance through categories allowing the user to automatically populate sub categories. This way information is passed auto matically from higher category levels to lower category levels making data input faster and more reliable (Figure 2-10). Figure 2-10. Model data hi erarchy & data interface in design (Source: Harvard university, Graduate school of Design) 34

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CHAPTER 3 RESEARCH METHODOLOGY Basic Modeling Data The research started with the modeling of a typical single family house in Florida. The general data was obtained from two sources: 1. Energy Information Administration (E IA) for general ch aracteristics of single family houses in U.S. 2. Florida Energy Efficiency Code Fo r Building Construction (FEECBC) For insulation and equipment efficiency values in Florida Table 3-1 shows the characteristics of a typical single family house in U.S. This data was studied for getting a quick idea about the ty pical number of room s; glass to floor ratio and type of heating and cooling equipment used in a single family house and then the appropriate values were selected from t he FEECBC data. Six houses were selected from FEECB data with approxim ately similar square foot area and geographical location as that of the intended base model hous e and the values were averaged for the following components: R value for internal and external walls R values for the roof R value for the floor U value for windows SHGC value for windows COP values for heating and cooling equipment Energy efficiency factor (EF) for hot water system Glass to floor ratio These values were then used as input data for the simulation purposes in the Design Builder software. All the units are in in ch-pound system which c an be changed to SI units if required by the user 35

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Table 3-1. Characteristics of a ty pical single family unit (EIA 2008). Number of occupants: 3 Floor space: Heating space (SF) 1,934 Cooling space (SF) 1,495 Garage 2-car Stories: 2 Foundation: Concrete slab Total rooms(2): 6 Bed rooms: 3 Other rooms: 3 Full bathroom: 2 Half bathroom: 0 Windows Area (3): 222 Number(4): 15 Type: Double pane Insulation: Well or Adequate Building Equipment: Space heating: Central Warm Air furnace Natural gas Water Heating: 49 Gallons Natural gas Space cooling: Central Air Conditioner Appliances: Refrigerator: 2-Door Top and Bottom 19ft 3 Clothes Dryer: Electric Clothes Washer: Top Loading Oven: Electric Television: 3 Ceiling Fans: 3 Printer: 2 1) This is a weightedaverage house that has combined characteristics of the Nations stock homes. 2) Excludes bathrooms 3) 11.5% of floor space 4) Based on a nominal 3x 5 window Source: EIA, 2005 Residential Energy Consumption Survey characteristics, April 2008 Simulation Input Data Location and climate: The study was intended to have a detailed energy analysis for a single family house in a hot and humid clim ate therefore Gainesville was selected as a geographical location in Florida. Based on the informa tion from EIA and FEECBC, the base model house was developed in Design Builder softw are with the demographics shown in Table 3-2 and the sections following it. 36

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Table 3-2. Data input for location and climate General Time and Daylight Saving Energy Codes Location Source WMO Climatic Region Latitude Longitude Elevation (m) Standard Pressure (KPa) Time zone Start of winter End of Winter Start of summer End of summer Legislative Region Gainesville FL, USA ASHRAE/ TMY3 722146 4A 29.70 -82.28 40.0 100.9 (GMT -05:00) Eastern Time Oct Mar Apr Sep Florida Structure: A. Wall construction Properties of the exterior walls that affe ct the energy use of the house include the type and thickness of insulation, thermal mass and air infiltration. a) Exterior walls are based on brick/block construction. Total width of the wall is 11.5 with the outer surface finished with 3 5/8 brick veneer and the inner layer composed of one course of half concrete block (Figure 3-1). Figure 3-1. Horizontal cross sect ion of the wall (Not to scale). 37

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An insulation of Extruded Polystyrene is s andwiched between two layers of the wall. The inner surface of the wall is cove red by 1/2 gypsum plastering. b) Interior partitions walls are 6 in wid th constructed with 2 x 4 gypsum plaster boards with 4 cavity between two board layers (Figure 3-2). Figure 3-2. Horizontal cross secti on of Interior wall (Not to scale). B. Roof Pitched roof is used with clay tiles (25mm) covering with air gap (20mm) on roofing felt (5mm). Figure 3-3. Vertical cross secti on of the roof (Not to scale). C. Floors The ground floor consists of a 6 concre te slab with 4 polystyrene insulation. The intermediate floor is a 4 concrete slab. Lighting: Recessed luminaries are used with flor escent light bulbs with the following properties: Lighting ener gy= 0.46 W/ft 2 38

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39 Radiant fraction=0.3 Visible fraction=0.18 Openings: Double glazing windows (4 high) are us ed with clear low emission glass (13mm argon-filled).These windows are Energy Star rated. Painted wooden window frames with dividers are used. Low transmittance window shading is also provided. Glass Area (20% of the floor space) = 900ft 2 Glass/Floor ratio=0.2 Heating and cooling Natural gas is used for heating and electric ity is used for cooling & domestic water heating system because this is the most common practice in Gainesville, FL. Central Air conditioner with COP=2.4 Natural gas based heating system COP=2.14 Electrical DHW COP=1.2 DHW consumption rate=0.013007gal/ft 2 /day Occupancy The model house was designed for occupan cy of 8 people which means a density of 0.0018 people/ ft 2 Metabolic factor was averaged for men, women and kids. Two computers are included in the daily usage for electricity. Metabolic Activity= Light Manual Work Metabolic factor= 0.9 All this data was used as input in the De signBuilder software to model and then to simulate the base model house.

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40 Table 3-3. Summary of the input data for simulation in DesignBuilder. Structure Lighting Openings HVAC OCCUPANCY Exterior walls Eight people which means a density of 0.0018 people/ ft 2 Metabolic Activity= Light Manual Work Metabolic factor= 0.9 DHW consumption rate= 0.013007gal/ft 2 /day Central Air conditioner with COP= 2.4 Natural gas based heating system COP= 2.14 Electrical DHW COP= 1.2 Glass/Floor ratio=0.2 Double glazing windows (13mm) Glass Area (20%of the floor space) = 900ft 2 Recessed Lighting is used with following properties: Lighting energy= 0.46 W/ft 2 Radiant fraction= 0.3 Visible fraction= 0.18 Interior Walls Roof

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CHAPTER 4 RESULTS Model design Design Builder software is used to model the house based on brick/block construction. The design was kept simple by creating an appropriate number of zones (area with similar functions were assigned to a single zone) to save time for simulation. Total area of the house is a two storey brick/block structure of approximately 4500 square feet and a garage space. The height of eac h storey is 12 from floor to floor and 10 from floor to ceiling. The model house is oriented with the main facade of the house facing to the north (Fig.4-1). The complete set of plans and elevations are in appendix A. The ground floor consists of two bedrooms, toilet, kitchen, dining, living area, laundry, entrance Lobby, stair case, storage and garage. The first floor consists of one bedroom, toilet, common room, study and computer room. Figure 4-1. Axonometric views of the base model house. 41

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Environmental Performance Analysis Annual Energy Consumption Internal heat Gains Internal heat gains include gains from equipment, lighting, occupancy, and HVAC. Results from the analysis have shown that ma jor part of internal gains is sensible cooling. Its annual value for this model is 33488 KBtu. C onsumption due to lighting is 22020 KBtu (Figure 4-2 (a)). The main contributor to the large value of cooling is solar gains through exterior windows. So this variable is very important in the design of the house. The model house is designed based on density value of 0.0018people/ft 2 which is not a big value of occupancy; theref ore the energy consumption value by the occupants is about 388 KBtu. Figure 4-2. Internal heat gains. A) Annual in ternal gains. B) Monthly internal gains breakdown. 42

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Envelope heat gains and losses Heat gains from the envelope include gains to the space from the surface element (walls, floors, ceilings etc.). Negative values indicate heat loss from the space. A large amount of energy is lost from the ground floors thr ough conduction. The major heat loses are from the floor and external infiltrations which accounts for 85% of the total heat losses in the house. The major heat gain components in the enve lope of the house are ceilings and walls which account for more than 73% of the total heat gains in the house (Figure 4-3 (a)). Figure 4-3. Energy consumption through envelope of the house. A) An nual energy consumption. B) Monthly energy consumption breakdown. 43

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Annual Fuel consumption Fuel breakdown Fuel breakdown shows that the electricity consumption for cooling is largest of all the values in the fuel breakdown. It reaches its maximum value in July and August and varies throughout the year with the change of weather. The second biggest consumer of electricity is lighting (22022 KBTU) and its consumption is almost uniform throughout the year (Figure 4-4 (b)). Gas is used for heating the house and has a value of 3412KBTU.S.o lighting and cooling are two critical elements in energy consumption and account for 88% of total electricity c onsumption in the house (Figure 4-4 (a)). Figure 4-4. Residential Fuel consumption. A) Annual fuel consumption. B) Monthly fuel breakdown. 44

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Total fuel consumption Electricity demand from June to August increases due to the hot and humid climate of Gainesville, FL. Ga s is used only for space heating in the house at the start and end of the year as it is a cheap source of f uel for heating. For the rest of the year it is just used for heating the water or cooki ng. Annual electricity and gas consumption is 50803 KBTU and 3412 KBTU respectively. Elec tricity accounts for 94% of overall annual energy consumption in the model house. Figure 4-5. Total fuel usage. A) Annual total fuel usage. B) Monthly breakdown of total fuel usage. Annual CO 2 production CO 2 emissions produced in a house vary as the use of electricity varies throughout the year. The total value of CO 2 emissions in a typical house in Gainesville, FL is 22,914 lbs which is 23 times the maximum allowance of CO 2 emissions per person 45

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per year (World Resource Institute 2010). Figure 4-6. CO 2 emissions. A) Annual CO 2 emissions. B) Monthly breakdown of CO 2. emissions. Validity of the Design Builder results The results from the Design Builder software are compared to the EIA data published in Building Energy data book (U.S DOE 2009) (Appendi x C). EIA data was selected for comparison because it is the most authenticated U.S. energy consumption data. The only problem is non-availability of the specific data for the selected location for the base model house. EIA data is av ailable for the broadly divided regions and therefore the values given are the averaged ones. Comparison shows approximately similar results to EIA and the diffe rences are due to the following: 46

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EIA values are national average values for the whole Southern region (Appendix C) and the data generated from Design Builder is parti cular to Gainesville, Florida. Florida falls in the South Atlantic regi on and some of the other Southern regions have a different climate than Gainesville, FL which affects the duration of cooling and heating annually. Gainesville has a hot and humid clim ate so cooling expenses are more than t he heating expenses. Moreover cooling is required for more than 9 months as compared to heating in the houses for creating comfortable indoor conditions which again is a big factor affecting overall expenses. Figure 4-7 shows a comparison of deliver ed end use energy values obtained from analysis and EIA data. Figure 4-7. Comparison of De signBuilder results and EIA data. The lighting and cooling values were com pared and not the heating values because the EIA data is for the whole Sout h region which consist of thr ee sub regions namely south Atlantic, east south central and west south centra l. Florida falls in S outh Atlantic region and in this division cooling degree-days (a measure of how much space cooling is needed in summer) averaged 2,071 per household, compared with a U.S. average of 47

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1,407. Again the observed difference is due to averaged value of EI A data for the whole south region. EIA has published related data in 2006 and ha s not yet published the most recent data for the annual energy expenses for the regions which affects the overall value. Therefore another source (Terrapass) was us ed for getting an approximate recent dollar amount for the energy expenses per year. Gainesville electr icity companies have their own rates for electricity and gas and these ra tes may differ according to the location. Comparison of results between Design Build er and EIA data (2006) shows a difference of $230 whereas comparison between Te rrapass and Design Builder shows a difference of just 1.83% (Figure 4-8). Figure 4-8. Comparison of annual energy expenditure. Figure 4-9 shows the comparison of results for annual CO 2 emissions. The data shows very little differences which really shows that the result s obtained from analysis through Design Builder are accurate. 48

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Figure 4-9. Comparison of CO 2 emissions results. Recommendation Metrics Significant measurable results were obtained that incorporated the basic concepts and technologies to provide a healthy, ener gy-efficient, and sustainable residential environment in hot and humid climates like Gainesville, FL. It has been concluded from the detailed energy anal ysis of the model house in Gaines ville, FL that the two major components of the annual energy consumption value are electricity for cooling and envelop losses especially fr om the floors and windows. Also proper insulation in roof attic, walls and floors plays a really important role in saving energy. The important parameters ( observed in the analysis) of the base model were modified and the results were compared to c heck the impact of those modifications on the overall energy performanc e of the model house. T he recommendations based on the comparative results of energy savings are as follows: 1. Try to control infiltration rate through des igning the airtight envelope of the house. 49

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Air infiltration rates can vary from le ss than 0.1ac/hr for a tight house under mild weather conditions to over 1.5ac/hr for a leaky house under severe weather conditions (Chan 2003). These values are derived from air leakage measur ements of residential houses in the U.S. Air infiltration can destr oy the performance of ventilation systems. Good ventilation design combined with opt imum air-tightness is needed to ensure energy efficient ventilation. The air change per hour (ac/hr) is determined by uncontrolled air leakage across the building envelope. Air infiltration is a function of the leakiness of the building, and the differential pressures across the envelope, which ar e caused by indoor-outdoor temperature difference and the forces exerted by wind. Th is is the uncontrolled flow of air into a space through adventitious or unintentional gaps and cracks in the building envelope. Air infiltration not only adds to the quantity of air entering the building but may also distort the intended air flow pattern to the detriment of overall indoor air quality and comfort. In the winter, cold air seeps into the building, r eplacing warm air that escapes through leaks in the envelope. In the summer, the opposite occurs. The base model house was modeled with infiltration rate of 0.6ac/hr. This is an averaged infiltration rate of typical single family homes in Florida. ASHRAE Standard 62.2 (2007) sets requirements for resident ial ventilation and acceptable indoor air quality. According to ASHRAE, the minimum v entilation rate is 0.35ac/hr for dwellings without compromising the internal air quality so decreasing the infiltration rate by 0.35 ac/hr in the base model house, the energy c onsumption is decreased by 49.24 (KBTU x 10^3) that is a decrease of 9.17% from the original value of the model house (Figure 410). 50

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Figure 4-10. Energy saving by controlling infiltration Table 4-1 shows the percentage of reduc tion in overall energy consumption (9.17%) and CO 2 emissions (7%) due to improved infiltration rate from 0.6ac/hr (base model house) to 0.35ac/hr. Table 4-1. Reduction in energy c onsumption by reducing infiltration Infiltration Values Energy consumption (KBTU x 10^3) Reduction in energy consumption (%) CO 2 Emissions(lbsx10^3) Reduction in CO 2 emissions (%) 0.6 ac/hr 54.21 22.914 0.35ac/hr 49.24 9.17 21.3 7 Assuming a 13 cents/KWh electricity rate in Gainesville, FL (just by controlling the infiltration rate) up to 10% on the electric ity bill can be saved annually (Figure 4-11). 51

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Figure 4-11. Dollar saving by controlling infiltration Table 4-2 shows that about 10% savings can be achieved by controlling the infiltration rate. Table 4-2. Savings by reducing infiltration Infiltration rate Annual electricity bills($) Dollar saving (%) 0.6ac/hr 2065.44 0.35ac/hr 1876.08 9.16% 2. The type of windows plays a very import ant role as windows are an integral part of the envelope of the house. For the base model house, double glazed (13mm), low emissivity windows (Argon Filled) were used (Energy Star recommended). The glazing with low-solar-gain (low-E coatings) can reduce solar heat gain signific antly with a minimal loss of visible light. Another advantage of using glazi ng with low emissivity is t hat in the summer and winter occupant comfort is increased; window tem peratures are more moderate and there are fewer cold drafts. Also discomfort from strong summer sunlight is reduced. 52

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Frame and glazing materials that resist heat conduction do not become cold and this result in less condensation. Using windo ws that significantly reduce solar heat gain means that cooling equipment costs may be reduced. Improved glazing, can reduce the intake of passive solar heat by about 75% and consequently reduce cooling needs.Results obtained by replacing the win dows with single glass showed that energy consumption consequently rose to about 9% more than the base model house (Figure 4-12). Figure 4-12. Energy saved by glass type. Table 4-3 shows that by replacing the windows with single glass (6mm), the energy consumption is increased by about 9% wh ich in turn is an increase in the utility bills. Also due to increase in the el ectricity consumption the amount of CO 2 emissions was increased by about 9%. 53

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Table 4-3. Savings by changing glass type Glass type Energy consumption (KBTU x 10^3) Increase in energy consumption (%) CO 2 emissions(lbsx10^3) Increase in CO 2 emissions (%) Double glazing 54.21 22.914 Single glazing 59.08 8.24 25.05 8.5 3. Natural ventilation should be used instead of mechanical ventilation. The mechanical ventilation system is an aggr essive electricity user and does not play much of an effective role for impr oving indoor air quality. Natural ventilation provides a more habitable environment for the people and also reduces the amount of energy for providing a quality ind oor environment. This allows for a lower size of heating and cooling equipment that will be installed in the house. The duration of operational time for the HVAC equipment can also be significantly reduced due to use of natural ventilation. So natural ventilation offers a lo w cost solution and it is really helpful in removing high summer heat gains from houses without the need for air conditioning If natural ventilation is chosen as a ventilation strategy, then it should be well designed and implemented, and not supported by poor l eaky building components. Natural ventilation with additional kitchen ex tract fans is common in single family houses. The base model house was revised with mechanical ventilation included and the change was responsible for 5% of addition in total energy loads which clearly means an increase of more than 5% annually in the utility bills (Figure 4-13). 54

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Figure 4-13. Energy saved by ventilation type. Table 4-4 shows the percentage increase in the energy consumption and CO 2 emissions due to switching to mechanical ventilation. Table 4-4. Percentage increase in energy consumption by mechanical ventilation. Type of ventilation Energy consumption (KBTU x 10^3) Increase in energy consumption (%) CO 2 emissions (lbsx10^3) Increase in CO 2 emissions (%) Natural ventilation 54.21 22.914 Mechanical ventilation(by zone) 57 4.89 24.09 5 4. Use lighting control as mentioned in Florida Building Code (FBC Section 13-415 Lighting) and also in International E nergy Conservation Code(IECC) standards 2000 (Section 805.2.1 & 805.2.2). Automatic switching or photocell controls for all exterior lighting are not intended for 24-hour operation. This controls the amount of lighting when required both in interiors and exteriors. By using more ener gy efficient lights, daylight, and dimmer 55

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sensors (to control lights based on occupancy) light energy use can be cut by 75 to 90%. Many lighting improvements, in cluding light-emitting diodes and compact fluorescent light bulbs (CFL s), could more than pay for themselves through reductions in energy use. The base model was revised with lightin g control on and it was observed that electricity consumption for lighting was reduc ed by almost half from the original value and an overall 18303 KBTU energy was saved ju st by introducing IECC lighting control system (Figure 4-14). This is a onetime expense but can save a lot of money throughout the life cycle of the house. Figure 4-14. Energy savi ngs by lighting control. Table 4-5 shows the percentage reduc tion in energy consumption and CO 2 emissions by introducing lighting control syst em in the base model house. Table 4-5. Reduction in energy c onsumption due to lighting control. 56

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57 General Practice Lighting Control (IECC 2000) %age decrease Energy consumption (KBTU x 10^3) 54.21 40 26 CO 2 emissions (lbs x10^3) 22.914 16.63 27.4 Other useful techniques for saving energy are as follows: 5. If using task or display lighting, use it for MINIMUM possible duration. 6. Use an efficient cooling and heating system with higher efficiencies. Large variations in energy consumption hav e been observed with different energy efficiency values of heating and ventilation equipment.

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58 Table 4-6. Recommendation Metrics Factors modified Values Energy cons.(KBTU x10^3) CO 2 emissions (lbs x 10^3) (% age) Comments Energy Consumption CO 2 emissions Base model 0.6ac/hr 54.21 22.9 Infiltration rate Modified 0.35ac/hr 49.24 21.3 Reduction 9.17 27 Reduce infiltration rate by making envelope of the house air tight Base model Double glazing 54.21 22.9 Glazing type Modified Single glazing 59.08 25.05 Increase 8.24 8.5 Use Energy star window glazing. These are double glazed argon filled windows Base model Natural 54.21 22.9 Ventilation type Modified Mech. 57 24.09 Increase 5 5 Design house considering natural ventilation (Passive design) Base model No control 54.21 22.9 Lighting Control Modified IECC (2000) 40 16.63 Reduction 26 27.4 Use lighting control(Dimming etc)

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CHAPTER 5 CONCLUSIONS About 80% of the energy used in the US is consumed in single-family homes and 84% of single-family homes have air conditi oning (central system, wall/window units, or both). This growing energy demand can only be offset by implementation of efficient techniques right from the design phase. A ll Important saving techniques should be implemented either during des ign (Infiltration rate, window types etc) or during installation of equipment (HVAC, Lighting etc) Once operational, these can save real money for the occupant throughout the service. In the past, performance assessment relied on using pre-selected design conditions, rules of thumb and manual calcul ations. At present, the advent of building energy simulation programs has enabled deta iled energy analysis of buildings before they are actually built. There has been an undeniably rapid development in computer technology and an increase in the number of avai lable building simulation tools over the last decade. The current generation of applic ations for the assessment of building performance ranges from simple spreadsheet s based on simplified calculation methods to advanced programs like DesignBuilder that is one of the simplest energy simulation softwares available nowadays. The followi ng conclusions have been drawn related to DesignBuilders capability and e fficiency from this research: Design Builder has proved to be accu rate and user-friendly energy analysis software. It can be used by designers, ar chitects, building services engineers, energy consultants, and university departments as well due to the simple features that allow DesignBuilder to be used effectively at any stage of the building design or operation. DesignBuilder gives very detailed results for energy consumption and CO 2 emissions. The building can be analyzed in yearly, monthly, daily, hourly and 59

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even sub hourly intervals which is really helpful for the people working on research works. Design Builder is simple to operate and gives nice graphical presentation and it does not consume a lot of time while si mulating the model as compared to other simulation softwares. DesignBuilder allows the user to model and the same time simulates the building in one application and errors are limited due to switching in between the software packages. With the help of parametric analysis techniques in DesignBuilder, designers can convince their clients by showing them how much energy they can save by using different alternatives for design and also for the heating and cooling equipment. With the help of a huge weather database, buildings can be analyzed for any geographical location in the world. DesignBuilder has many important opt ions for analysis related to indoor and outdoor air quality and also heat trans missions from the building. Design Builder has a built in library fo r different construction materials and even new materials can be added with required specifications. 60

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The ever increasing U.S. energy demand by society can only be curbed with the use of modern simulation technology to addr ess all the energy related issues in the housing sector of U.S. This will also be really helpful in controlling CO 2 emissions which is also a major environmental issue. The early stages of build ing design include a number of decisions which have a strong influence on the performance of the building throughout the rest of the proce ss. It is therefore important that designers are aware of the consequences of these design decisions. With the current intensive energy situation it is more feasible to control the energy consumption at the design stage rather than after actual construction. These simulation programs can greatly contribute toward mo re feasible design decisions when used during the building design process to predi ct the performance of various design alternatives with respect to considerations such as energy, CO 2 emissions and Indoor air quality. This is inevitable right now becau se in the past few years the square foot area for the average house has been increased and it is expec ted to continue in the future also. So this is the best time to incorporate the simple available simulation technology like Design Builder in our design phase in order to save energy and the environment for us and for future generations. 61

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APPENDIX A DRAWINGS OF THE MODEL HOUSE Plans Note: All the Drawings are not to scale. Ground Floor Plan 62

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First floor Plan: 63

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Axonometric Views 64

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Another Axonometric view 65

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Elevations South Elevation 66

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West Elevation: 67

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APPENDIX B TABLES FOR ANALYSIS GRAPH RESULTS 68

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APPENDIX C LIST OF USEFUL WEBSITES U.S. Agencies and National Organizations Efficient window collaborative http://www.efficientwindows.org/ National Energy Foundat ion http://www.nef1.org/ State master http://www.statemas ter.com/state/FL-florida/ene-energy The construction Industry Compliance Assistance Center(CICA) http://www.cicacenter.org /or-greenbuilding.html U.S. Energy Star Progra m http://www.energystar.gov/ U.S. Department of Energy Ener gy Efficiency and Renewable Energy Information -http://www.eere.energy.gov/ U.S. Department of Energy C onsumer Energy Efficiency Tips http://www.eere.energy.gov /consumer/your_home/ US Energy Information Administration http://www.eia.doe.gov/emeu/states /sep_sum/html/pdf/sum_ex_res.pdf U.S. Department of Energy Cons umer Energy Saving Information http://www.energysavers.gov/ State Agencies and Organizations Florida performs http://www.flori daperforms.com/Indicators.aspx?si=SI_029 Florida Public Service Commissi on http://www.floridapsc.com Florida Department of Environmental Protection http://www.dep.state.fl.us Florida Energy Office http: //www.dep.state.fl.us/ energy/default.htm Florida Solar Energy Center http://www.fsec.ucf.edu/en/ Florida Weatheriz ation Assistance http://www.floridacommunitydevelopment.org/wap/index.cfm Floridas Electric Utilities Subject to FEECA 70

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Florida Power & Light Company http:/www.fpl.com/ Florida Public Utilities Company http://www.fpuc.com/ Gainesville regional utilities www.gru.com Progress Energy Florida, Inc. http://www.progress-energy.com/ 71

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APPENDIX D VALIDITY DATA 72

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LIST OF REFERENCES ASHRAE Standard 62.2. (2007). Ventilation and Acceptable Indoor Air Quality in Low Rise Residential Buildings, American So ciety of Heating, Refrigerating and Air Conditioning Engi neers, Atlanta, GA. Combs S. (2008). The Home Energy E fficiency Report, Texas State Energy Conservation Office (SECO), Texas U.S. Crawley D., Hand J., Kummert M., Griffith B. (2008). Contrasting the capabilities of building energy performance simulation programs, Journal of Building and Environment, 43, 661-673. Diamond R. (2001). An overview of the U.S. Building stock, Chapter 2.1, Spengler J.D. et al., Indoor Air Quality H andbook, New York: McGraw Hill. Energy Information Administration, (2008). U. S. Carbon Dioxide Emissions from Energy Sources 2007 Flash Estimate, DOE U.S. Florida Public Service Commission, (2009). A nnual report on activities pursuant to the Florida Energy efficiency and cons ervation act, section 366.82(10) and 377.703(2). Ibarra D., Reinhart C. ( 2009) Building Performance Simulation for Designers, DesignBuilder EnergyPlus Tutorial #1, Graduate school of Design, Harvard University, U.S. IEA (2008) Worldwide trends in energy use and efficiency, http://www.worldenergyoutlook.org /docs/weo2008/WEO_2008_Chapter_8.pdf (January 17, 2010). Laptali E., Bouchlaghem N., and Wild S. (1997). Planning and estimating in practice and the use of integrated computer models, Automation in construction, 7, .71-76. Milon J. (1991). Chapter 1 Introduction, Energy In formation Handbook, Energy Information Document 1028, series of t he Florida Energy Extension Service, Florida Cooperative Extension Service, Inst itute of Food and Agricultural Sciences, University of Florida U.S. National Association of Home Builders, (2007). Housing Facts, Figures and Trends and Single-Family Square Footage by Loc ation, U.S. Census Bureau. Omer A. (2009). Energy use and environmental impacts: A general review, Journal of renewable and sustainable energy, 1, 053101-1. 75

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Petersen S., and Svendsen S. (2010). Method and simulation program informed decisions in the early stages of building design, Journal of Energy and Building, Elsevier Science Ltd, Article in press. Pitts A. (1994). Building design: Realizing the benefits of renewable energy technologies, Journal of renewable energy, Elsevier Science Ltd, 5, 959-966 Roth K. (2008). Home energy displays: Em erging Technologies, ASHRAE Journal,136 Robert J., and Hitchcock. (2002). Metracker version 1.5: Life-cycle performance metrics tracking. Reference Manual, Law rence Berkeley National Laboratory, Building technology Department, U.S. Sheridan L. (2009). Investi gating the Sullivan report reco mmendations: Development of a standardized methodology for post occupancy evaluation of recently built housing, Research, Sustainability and LZCT, Building Standards Division Report, Glasgow. Tindale A. (2004). Design Buil der and Energy Plus, Buildi ng Energy Simulation User News, 25(1), UK. U.S. Energy Information Administration, http://www.eia.doe.gov/ emeu/recs/contents.html (January 9, 2010) Wilson, A., and Boehland J. ( 2005) Small is Beautiful, U.S. house size, resource use, and the environment. Journal of Industrial Ecology, 9(1), 277-287. World Energy Outlook, IEA (2008). http://www.worldenergyoutlook .org/docs/weo2008/chapter10.pdf (Feb., 16 2010) World Resources Institute, (2010). WRI summary of th e carbon limits and energy for Americas renewal act, Washington DC. 76

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BIOGRAPHICAL SKETCH Adeeba Abdul Raheem is an International student at M.E. Rinker, Sr. School of Building Construction. She co mpleted her bachelors degree in architectural engineering and design from University of Engineering & Te chnology PK. Before coming to the U.S. she was working as a Lecturer/ research assistant in UET PK. She has worked in a greater detail about the env ironmental effects on Histori cal Mughal heritage in Lahore Pakistan. She has also produced a paper entitled as Mughal Heritage under the Cloud of Demolition: Environmental effects on monum ents in Journal of Building Appraisal, Palgrave Macmillan. During her Graduate studies in M.E. Rinker, Sr. School of Building Construction, she found out the fact that t he rapid development of urbani zation places a huge strain on builders to build not only comfortable and solid but also environmentally and humanfriendly buildings. She also believes that buildings act as bridges between different cultures, incarnating the character of a par ticular society and reflecting the power and endless potential of man's genius. She hopes to make a valuable contribution to the humanity with her previously obtained expertise and devoted enthusiasm towards construction profession. 77