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Design and Analysis of a Net-Zero Energy Commercial Office Building in a Hot and Humid Climate

Permanent Link: http://ufdc.ufl.edu/UFE0042256/00001

Material Information

Title: Design and Analysis of a Net-Zero Energy Commercial Office Building in a Hot and Humid Climate
Physical Description: 1 online resource (90 p.)
Language: english
Creator: Vu, Thomas
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: building, energy, sustainable, zero
Mechanical and Aerospace Engineering -- Dissertations, Academic -- UF
Genre: Mechanical Engineering thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The purpose of this study is to analyze the design and economic benefits of a net-zero small office building in the hot and humid climate of Florida. Hot and humid climates are cooling dominated and require constant cooling and dehumidification to achieve a comfortable indoor environment, but lead to higher cooling energy costs. Being the most prevalent type of commercial building in Florida, net-zero small office buildings have the greatest potential in energy savings in Florida next to residential homes. Various building designs are examined to reduce energy consumption of the building by utilizing energy modeling software. The final package of energy efficiency measures achieves 59% in energy savings of an established energy model baseline. A photovoltaic (PV) system provides the annual energy needs of the small office building. A life cycle cost (LCC) analysis determines whether the additional first costs associated with the net-zero small office design will pay back in energy cost savings. The results proved that the measures used to achieve 59% energy savings were cost effective. In addition, the PV system selected to generate the necessary energy for the small office building was cost effective as long as it met certain efficiency and cost criteria.
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 Thomas Vu.
Thesis: Thesis (M.S.)--University of Florida, 2010.
Local: Adviser: Ingley, Herbert A.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-12-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0042256:00001

Permanent Link: http://ufdc.ufl.edu/UFE0042256/00001

Material Information

Title: Design and Analysis of a Net-Zero Energy Commercial Office Building in a Hot and Humid Climate
Physical Description: 1 online resource (90 p.)
Language: english
Creator: Vu, Thomas
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: building, energy, sustainable, zero
Mechanical and Aerospace Engineering -- Dissertations, Academic -- UF
Genre: Mechanical Engineering thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The purpose of this study is to analyze the design and economic benefits of a net-zero small office building in the hot and humid climate of Florida. Hot and humid climates are cooling dominated and require constant cooling and dehumidification to achieve a comfortable indoor environment, but lead to higher cooling energy costs. Being the most prevalent type of commercial building in Florida, net-zero small office buildings have the greatest potential in energy savings in Florida next to residential homes. Various building designs are examined to reduce energy consumption of the building by utilizing energy modeling software. The final package of energy efficiency measures achieves 59% in energy savings of an established energy model baseline. A photovoltaic (PV) system provides the annual energy needs of the small office building. A life cycle cost (LCC) analysis determines whether the additional first costs associated with the net-zero small office design will pay back in energy cost savings. The results proved that the measures used to achieve 59% energy savings were cost effective. In addition, the PV system selected to generate the necessary energy for the small office building was cost effective as long as it met certain efficiency and cost criteria.
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 Thomas Vu.
Thesis: Thesis (M.S.)--University of Florida, 2010.
Local: Adviser: Ingley, Herbert A.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-12-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0042256:00001


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1 DESIGN AND ANALYSIS OF A NET ZERO ENERGY COMMERCIAL OFFICE BUILDING IN A HOT AND HUMID CLIMATE By THOMAS P. VU A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREME NTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2010

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2 2010 Thomas P. Vu

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3 To my parents, whose guidance is invaluable

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4 ACKNOWLEDGMENTS First, I would like to thank my parents and family f or all the support they have given me. My parents taught me that education is the first and foremost aspect of my life. I would also like to thank the members of my committee, Dr. Kibert, Dr. Sherif, and espe cially my graduate advisor Dr. Ingley. I woul d also like to thank my girlfriend, Elaine, for her support through this endeavor. Finally, I would like to thank all my friends and colleagues throughout the years who have influenced and shaped me in one way or another into the person I am today.

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5 TABL E OF CONTENTS page ACKNOWLEDGMENTS ...............................................................................................................4 LIST OF TABLES ...........................................................................................................................8 LIST OF FIGURES .........................................................................................................................9 ABSTRACT ...................................................................................................................................10 1 INTRODUCTION ..................................................................................................................11 Background and Motivation ...................................................................................................11 Net Zero Energy Buildings Definitions ...............................................................................12 Net Zero Energy Buildings Examples .................................................................................13 Barriers to Net Zero Energy Buildings ...................................................................................14 2 LITERATURE REVIEW .......................................................................................................17 Commercial Building Energy Consumption and Modeling ...................................................17 Commercial Buildings Energy Consumption Survey ...................................................17 Department of Energy Commercial Benchmark Energy Models .................................17 Feasibility and Case Studies ...................................................................................................18 Feasibility ......................................................................................................................18 Case Studies ..................................................................................................................19 American Society of Heating, Refrigerating and Air Conditioning Engineers Energy Efficiency Standards and Design Guides ......................................................................19 ASHRAE Standard 90.1 ...............................................................................................19 ASHRAE Design Guides ..............................................................................................20 3 METHODOLOGY .................................................................................................................22 Evaluation Approach ..............................................................................................................22 Simulation Tool Description ...................................................................................................23 Development of the Small Office Building Prototype ...........................................................25 4 BASELINE MODEL DEVELOPMENT ...............................................................................28 Building Operating Characteristics .........................................................................................28 Baseline Building Envelope Characteristics ...........................................................................29 Exterior Walls ...............................................................................................................30 Roof ...........................................................................................................................30 Slab On Grade Floors ...................................................................................................31 Fenestration ...................................................................................................................31 Air Infiltration .........................................................................................................................32 Internal and External Loads ....................................................................................................33

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6 People ...........................................................................................................................33 Lighting .........................................................................................................................34 Miscellaneous Equipment (Plug Loads) .......................................................................34 Baseline Building Heating, Ventilation and Air Conditioning Systems ................................35 Building HVAC Operating Schedule ............................................................................35 HVAC Zoning and Heating and Cooling Thermostat Setpoint ....................................35 HVAC Equipment Sizing ..............................................................................................35 HVAC Equipment Effic iency .......................................................................................36 HVAC System Fan Power ............................................................................................38 Outdoor Air Ventilation and Exhaust Rates ..................................................................39 Economizer Use ............................................................................................................40 Service Hot Water System ......................................................................................................41 Hot Water Usage ...........................................................................................................41 Storage Tank Size .........................................................................................................41 Input Power and Standby Heat Loss Coefficient ..........................................................42 5 PROPOSED MODEL DEVELOPMENT ..............................................................................43 Building Envelope Energy Efficiency Measures ....................................................................44 Enhanced Wall Assembly .............................................................................................44 Cool Roof ......................................................................................................................45 High Performance Windows and Shading Devices ......................................................45 Lighting Energy Conservation Measures ...............................................................................46 Reduced Interior Lighting Power ..................................................................................46 Occupancy Sensor Control ............................................................................................46 Daylight Harvesting ......................................................................................................47 Miscellaneous Equipment (Plug Loads) Measures .................................................................48 HVAC System Measures ........................................................................................................49 Geothermal Heat Pump System ....................................................................................49 Dedicated Outdoor Air System .....................................................................................53 Service Water Heating Measures ............................................................................................54 On Site Energy Generation .....................................................................................................54 6 SIMULATION RESULTS .....................................................................................................56 Baseline Model Energy Simulation Resu lts ...........................................................................56 Advanced Model Energy Simulation Results .........................................................................58 7 COST ANALYSIS .................................................................................................................60 8 CONCLUSIONS ....................................................................................................................63 Design and Energy Analysis ...................................................................................................63 Life Cycle Cost Analysis ........................................................................................................64 Recommendations for Future Research ..................................................................................64

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7 APPENDIX A SMALL OFFICE FLOORPLAN AND ROOM DESCRIPTIONS ........................................66 B BASELINE M ODE INPUTS .................................................................................................68 C PROPOSED MODEL INPUTS ..............................................................................................80 D BASELINE ENERGY SIMULATION OUTPUT .................................................................84 E PROPOSED ENERGY SIMULATION OUTPUT ................................................................85 F LIFE CYCLE COST CALCULATIONS ...............................................................................86 LIST OF REFERENCES ...............................................................................................................87 BIOGRAPHICAL SKETCH .........................................................................................................90

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8 LIST OF TABLES Table page 11 Zero energy building list .........................................................................................................14 31 Small office prototype thermal zone characteristics ...............................................................27 41 Lighting power density and plug load density by HVAC zone ..............................................34 42 Fan energy, cooling EIR, and heating EIR baseline model summary ....................................39 42 Ventilation and exhaust rates by HVAC zone ........................................................................40 51 Lighting power of baseline model and proposed model .........................................................47 52 Plug load of baseline model and proposed model ..................................................................48 53 Percent reduction of Energy Star equipment ..........................................................................49 54 Performance characteristics of geothermal heat pumps .........................................................53 55 PV Watts v2.0 PV simulation results .....................................................................................55 61 Annual energy end use breakdown of the baseline model .....................................................57 62 Annual energy end use breakdown of the proposed model ...................................................59 71 Summary of proposed package LCC analysis ........................................................................62 72 Summary of PV system LCC analysis (including proposed package costs) ..........................62 A 1 Small office building room descriptions ................................................................................67 B 1 Building load schedules .........................................................................................................68 B 2 Baseline model lighting power calculations ..........................................................................72 B 3 Baseline model plug load calculations ...................................................................................73 B 4 Baseline office equipment power usage ................................................................................74 B 4 EIR calculations for heating and cooling ...............................................................................75 B 5 Minimum outdoor air calculations .........................................................................................77 C 1 Proposed model lighting calculations ....................................................................................80 C 2 Proposed model plug load calculations ..................................................................................82

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9 LIST OF FIGURES Figure page 31 Small commercial office building prototype floor plan .........................................................27 32 Office floor plan thermal zoning ............................................................................................27 41 Weekday schedule for small office building prototype ..........................................................29 42 Axonometric view of the eQuest small office building model ...............................................30 51 Correlation between annual building energy consumption and added wall insulation. .........44 52 Proposed model with the addition of window overhangs on the south faade. ......................46 53 PV system efficiency range and output ..................................................................................55 61 Annual energy end use percentage of baseline model ...........................................................57 62 Annual enduse percentage of proposed model ......................................................................59

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10 Abstract of Thesis Presented to th e Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science DESIGN AND ANALYSIS OF A NET ZERO ENERGY COMMERCIAL OFFICE BUILDING IN A HOT AND HUMID CLIMATE By Thomas P. Vu August 2010 Chair: H.A. Ingley Major: Mechanical Engineering The purpose of this study is to analyze the design and economic benefits of a net zero small office building in the hot and humid climate of Florida. Hot and humid climates are cooling dominat ed and require constant cooling and dehumidification to achieve a comfortable indoor environment, but lead to higher cooling energy costs. Being the most prevalent type of commercial building in Florida, net zero small office buildings have the greatest p otential in energy savings in Florida next to residential homes. Various building designs are examined to reduce energy consumption of the building by utilizing energy modeling software The final package of energy efficiency measures achieves 59% in energy savings of an establ ished energy model baseline. A photovoltaic ( PV ) system provides the annual energy needs of the small office building. A life cycle c ost (LCC) analysis determine s whether the additional first costs associated with the net zero sm all office design will pay back in energy cost savings. The results proved that the measures used to achieve 59% energy savings were cost effective. In addition, the PV system selected to generate the necessary energy for the small office building was cost effective as long as it met certain efficiency and cost criteria.

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11 CHAPTER 1 INTRODUCTION Background and Motivation As concerns over energy independence in the United State s and global warming increase well into the 21st century, many are seeking ways t o continually increase energy e fficiency and reduce energy consumption. C ommercial and residential buildings alone account for 40% of primary energy consumption in the United States and 70% of electricity usage (CBECS, 2003) The demand for e nergy by the commercial sector is projected to increase by 1.2% per year from 2006 to 2030, driven by trends in population and economic growth (EIA, 2009) In order to reduce the energy consumption of the commercial building sector, the Department of Energy (DOE) ha s established the Commercial Building Initiative, a goal to create technologies and design approaches that lead to marketable zero energy commercial buildings (ZEB) by 2025. This goal is evident in Section 422 of the Energy Independence and Security Act of 2007, which call s for the increased production of clean renewa ble fuels and increased efficiency of products, buildings, and vehicles (EISA, 2007) Today, more and more building owners are looking to have their existing or new building be green, a term ubiquitous with clean energy and environmental friendliness. Whether driven by financial or environmental reasons, t he green movement is driving building designers and engineers to develop ever more inventive methods to conserve energy in buildings. New materials, techniques, technologies, and computer modeling programs have helped energy efficient buildings come to life. However, despite the gains in lower energy use and improved building quality, the question all building owners ask about new technolo gies is What will it cost?

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12 Net Zero Energy Buildings Definitions There are several definitions for a ZEB. Each definition differs depending on the boundary and metric used to define the building. A net ZEB is, ideally, a building that through high ef ficiency gains can meet the rest of its energy needs through renewable technologies. Zero is the point at which the building no longer consumes energy but rather produces it. At the zero point, the sum of the energy flows in equal the sum of the energy f lows out. There are four definitions used for ZEBs: netzero source energy building, net zero site energy building, net zero energy cost building, net zero energy emissions buildings A source ZEB produces at least as much energy as it uses in a year, wh en compared to the energy produced at the source. Source energy refers to the primary energy used to generate and deliver the energy to the site. The boundary of the system encompasses the building, transmission system, power plant, and the energy requir ed getting the fuel source to power the plant. To calculate a buildings total source energy, both imported and exported energy is multiplied by an appropriate site to source energy factor. This definition is difficult to assess since it depends on the m ethod the utility is buying and producing power (Torcellini et al, 2006). A site ZEB produces at least as much energy as it uses in a year, when accounted for at the site. This definition tends to promote energy efficient designs and can be easily verifie d through metering (Torcellini et al, 2006) Photovoltaic systems, small scale wind power, or solar hot water collectors are options to generate on site power. However, this definition does not distinguish between fuel types. One unit of electricity on site is considered equal to one unit of gas on site; however, electricity may be worth three times more at the source than gas. For buildings that use a significant amount of gas, a site ZEB will need to generate much more electricity on site than a sourc e ZEB.

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13 In a cost ZEB, the amount of money the utility pays the building owner for the energy the building exports to the grid is at least equal to the amount the owner pays the utility for energy services and energy used over the year. However, since util ity rates v ary fro m year to year, a ZEB that has consistent energy performance can meet a cost ZEB goal one year and fail the next year. Also, if a significant number of buildings meet a cost ZEB goal fewer funds would be available to maintain the utility infrastructure (Torcellini et al, 2006) Thus, the utility would have to charger higher fixed and demand rates to customers. An emissions ZEB produces at least as much emissions free renewable energy as it uses from emissions producing energy sources. A chieving a zero emissions goal depends widely on the method of source energy production, whether it be nuclear, hydro, coal, or wind. If a building consumes energy from an entirely wind generated source, then that building will not need to produce any onsite energy. However, if a building is a in a mixed field of energy generation sources, say coal and wind power, it is much more difficult to determine the amount of onsite energy needed to be produced (Torcellini et al, 2006) Net Zero Energy Buildings Examples The U.S. Department of Energys Building Technologies Program website maintains the Zero Energy Buildings database. Currently, e ight ZEBs located in the U.S. are listed along with their project information as well as energy performance charact eris t i cs, listed in Table 1 1. These buildings had aggressive energy saving goals when being designed. Off the shelf energy saving technologies were used in conjunction with daylighting, radiant heating, natural ventilation, evaporative cooling, ground source heat pumps, photovoltaics, and passive solar strategies to reduce their energy use and m inimize environmental impacts (DOE, 2008)

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14 Table 1 1. Zero energy building l ist Building Name Building Type Floor Area (ft2) Annual Energy Generated (kBtu/ft 2 ) Annual Energy Purchased (kBtu/ft 2 ) Total Project Cost Aldo Leopold Legacy Center Commercial Office; Interpretive Center 11,900 17.6 2.02 $3,943,418 Audubon Center at Debs Park Recreation; Interpretive Center; Park 5,020 17.1 $5,500,000 Challengers Ten nis Club Recreation 3,500 9.17 0.0955 $1,800,000 Environmental Tech. Center, Sonoma State Higher Education, Laboratory 2,200 3.79 1.47 $1,116,000 Hawaii Gateway Energy Center Commercial Office; Interpretive Center; Assembly; Other 3,600 31.1 3.46 $3,400,000 IDeAs Z Squared Design Facility Commercial Office 6,560 0.00052 Oberlin College Lewis Center Higher Education; Library; Assembly; Campus 13,600 36.4 4.23 $6,405,000 Science House Interpretive Center 1,530 17.6 0 $650,000 Barriers to Net Zer o Energy Buildings If the strategy and technologies exist to build more energy efficient buildings, then the question is how come all buildings in the country are not moving towards net zero. The fault may be in the traditional way of designing buildings as well as perceived associated higher costs with green buildings. Many building designers still design their respective systems individually without giving considerations on how much their system a ffects other building systems. In the traditional building design process, the architectural team works with the owner to create a building program that specifies the needs for the building. The architect designs the building to satisfy the program requirements, and then the project engineers design the elect rical and mechanical

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15 systems and evaluate compliance with energy codes and acceptable levels of environmental comfort. However, because many important architectural decisions are set at this point, few changes can be made that wo uld improve energy perform ance. In contrast to the traditional building process, the whole building de sign process requires the team, including the architect, engineers (lighting, electrical, and mechanical), energy and other consultants, and the buildings owner and occupants, to work together to set and understand the energy performance goals. The full design team focuses from the outset on energy and energy cost savings. The process rel ies heavily on energy simulation. To be effective, the process must continue through design, construction, and commissioning (Torcellini et al, 2006a) Despite the inherit benefits of reducing or eliminating energy costs, building owners ultimately ask how much of an investme nt must be made and what is the value of such an investment. The cost of such a project varies greatly depending on the strategy undertaken to reduce energy use and the climate in which the building is constructed. Langdon (2007) showed that there wa s no significant difference in the cost of green buildings vs. nongreen buildings G reen building construction projects around the country meeting LEED certification showed an average upfront cost of 2% of project cost with as high of an upfront cost of 6% of project cost (Kats, 2003) Fisk (2000) and Heerwagen (2001) showed other added financial benefits in i mproved indoor air quality and incr eased indoor daylighting, which lead to substantial savings in work productivity and moral. The purpose of this study is to analyze the design and economic benefits of a net zero sma ll office building in the hot and humid climate of Florida. Hot and humid climates are cooling dominated and require constant cooling and dehumidification to achieve a comfortable

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16 indoor environment, but lead to higher cooling energy costs. Being the most prevalent type of commercial building in Florida, net zero small offices will have the greatest potential in energy savings in Florida next to residential homes. Various building designs will be explored to reduce energy consumption of the building. The f inal design solution, however, is intended not to be the optimal solution, as there are many variations of design that could achieve the same effect The economic analysis will only be limited to construction costs and energy costs A Life Cycle C ost (LC C) analysis will help determine whether the first costs associated with the net zero small office design will pay back in energy cost savings

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17 CHAPTER 2 LITERATURE REVIEW Commercial Building Energy Consumption and Modeling The Commercial Buildings Energy Consumption Survey (CBECS) is a national sample survey performed by the federal Energy Information Administration (EIA) every four years. The survey collects information on the U.S. stock of commercial buildings, their energy related building character istics, and their energy consumption and expenditures. The CBECS provides valuable information regarding the energy performance characteristics of the current U.S. stock of commercial buildings. Commercial Buildings Energy Consumption Survey The CBECS def ines commercial buildings as buildings in which at least half of its floor space is used for purposes other than residential, industrial, or agriculture. Therefore, this survey includes buildings that are not typically thought of as commercial buildings, such as schools, prisons, and buildings for religious worship. According to the 2003 CBECS, office buildings were the most numerous type of building and comprise of 19% of total commercial floor space and 17% of energy use, ranking highest above all other principal building activities (CBECS, 2003) The southern region, which includes hot and humid Florida, had the most office square footage of the entire country as well as the most energy consumption. The southern region also had lower energy use intens ity (EUI) when compared to the Northeast and the Midwest, but a higher EUI when compared to the West. Department of Energy Commercial Benchmark Energy Models To determine the value of implementing a certain energy saving building technology, the DOEs Na tional Renewable Energy Laboratory (NREL) developed modeling methodologies to attempt to model the current building stock based on the 2003 CBECS. The study found energy

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18 models using EnergyPlus modeling software were roughly consistent with the 2003 CBECS survey. The modeling methods utilized were valid and could be used to model the building sector (Griffith et al, 2008). The NREL developed commercial energy model benchmarks in order to establish a common comparison baseline so that researches studying building energy efficiency and net zero buildings could compare their findings. Fifteen typical building types were developed based on information from the 2003 CBECS The building prototypes were categorized into three vintage s and 16 locations based on climate zone and modeled in EnergyPlus An attempt was not made to match CBECS energy use data. The results showed a small 5,500 ft2 office building in hot and humid Houston, TX had an annual energy consumption of 33.6 kBtu/ft2 compared to th e 2003 CBECS average of 79.9 kBtu/ft2 (Torcellini et al, 2008). Feasibility and Case Studies Feasibility The NREL also studied the technical feasibility of commercial ZEBs The main question determined by the study was to what extent a photovoltaic system can provide for a building s energy needs. Based on EnergyPlus simulations of various buildings and existing and projected technologies to 2025, the study found that 62% of buildings could reach net zero (Griffith, 2007) Concurrently, 47% of building f loor space could achieve net zero. The study also found, a ssuming exportation of excess electricity from PV systems, new buildings could, on average, consume only 12.2 kBtu/ft2, which wa s an 86% reduction from current stock. Office buildings, when compar ed to ASHRAE Standard 90.12004, required 67% in energy savings to reach the ZEB goal. A sector analysis showed that office buildings have a below average chance of achieving net zero, due largely in part to high plug and process loads and building height Ranking

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19 individual technologies ability to reach the ZEB goal t he po tential to reduce net site EUI wa s highest for thermal insulation, followed by lighting, plug and process loads, HVAC, dynamic windows, daylighting, and passive solar. The assessment concluded that achieving a ZEB goal was more achievable than generally assumed. Case Studies The Buildings and Thermal System Center at the NREL studied six high performance buildings over a four year period to understand the issues in the design, construction, operation, and evaluation of low energy buildings in order to det ermine best practices that should be applied to future buildings to reach the ZEB goal (Torcellini et al, 2006a) The study found value was favored over cost and a whole building desi gn approach wa s a good way to lower energy and cost. However, the buildings used more energy than predicted in the design and simulation stage. T he higher than predicted energy use resulted from higher than predicted plug loads, PV system degradation, and unpredictable occupancy behavior Each of the buildings saved 25% to 70% in energy lower than code. Energy monitoring provided valuable feedback in maintaining efficient performance of building systems in order to reach design goals. A set of best pra ctices were developed from the study to be applied to future designs of low energy buildings and ZEBs. Further details of the best practices can be found in the literature. American Society of Heating, Refrigerating and Air Conditioning Engineers Energy E fficiency Standards and Design Guides ASHRAE Standard 90.1 Originating in 1975 in response to that decades energy crisis, t he American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) developed ASHRAE Standard 90.1. Standard 90.1 provides minimum energyefficient requirements for the design and construction of new buildings and their systems. Standard 90.1 has been widely adopted as

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20 building code throughout many regions in the U.S. and applies to all buildings except for low ris e residential buildings (three habitable floors or less). The standard specifies reasonable design practices and technologies that minimize energy consumption without sacrificing either the comfort or productivity of the occupants. Appropriate for a wide range of building types, climate zones, and site conditions, the provisions of this standard apply to envelopes of buildings, HVAC equipment, service water heating equipment, and power and lighting. Standard 90.1 is continually being revised and publishe d every three years. In addition to being used for code compliance, Standard 90.1 is often used as a baseline for energy efficient and green building programs, such as the U.S. Green Building Councils (USGBC) Leadership in Energy and Environmental Design (LEED). ASHRAE added Appendix G with the 2004 update to Standard 90.1 to outline a procedure to show that the building design is significantly better than code minimum. The Performance Rating Method procedures in Appendix G intend to provide more flexibi lity and to give credit for energy savings measures such as building orientation, natural ventilation, daylighting, and HVAC system design and selection. The method outlined in Appendix G establish es a baseline for the entire energy consumption of the bui lding to be used to calculate percentage energy savings However, it does not reward energy savings in plug and process loads as it considers these loads equal in both the baseline and proposed models. Plug and process loads include appliances, office equipment, computers, monitors, and other electrical and gas equipment. ASHRAE Design Guides ASHRAE has published several building type ad vanced energy design guidelines to achieve energy efficiency surpassing Standard 90.1. Currently, the guides provide methods to achieve 30% ef ficiency over 90.11999 for small warehouses, K 12 schools, highway lodgings small office buildings, and small retail buildings Event ually the ultimate goal of the advanced

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21 energy guides is to provide de signers methods to achieve a net zero energy building based on the type of building being designed. For this study, the Advanced Energy Design Guide for Small Office Buildings was used as a starting point for design in achieving net zero In addition, The ASHRAE Green Guide was utilized to id entify methods in designing mechanical systems for sustainable buildings as well as identify possible energy saving building technologies Also, the ASHRAE Design Guide for Hot and Humid Climates was utilized to identify key issues for desig ning buildings in hot and humid climates.

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22 CHAPTER 3 METHODOLOGY Evaluation Approach The objective of this study wa s to assess and quantify the energy savings potential of a small commercial office building located in a hot and humid climate. The percent savings goal was based on the definition of net site energy use: the amount of energy used by a building minus any renewable energy generated within its footprint. The whole building energy savings method was used to determine energy savings to achieve a net zero energy building, in line with the Performance Rating Method detailed in Appendix G of Standard 90.12004 (ANSI/ASHRAE/IESNA 2004a) Historically, energy savings have been expressed in two ways: for regulated loads only and for all loads (whole bui lding). Regulated load metrics did not include plug and process loads that were not code regulated. Whole building energy savings, on the other hand, included all loads (regulated and unregulated) in the calculations. In general, whole building energy s avings were more challenging than regulated load savings given the same numerical target, but more accurately represented the impact of the building on the national energy system. In order to fulfill the objective, existing floor plans of a small commerc ial office building were utilized as a starting point to develop a prototype small commercial office building Once a prototype building was established, a baseline mode l of the prototype bu ilding was created as dictated by the criteria of Appendix G of A SHRAE 90.12004 (ANSI/ASHRAE/IESNA 2004a) The baseline prototype building was then simulated using the Typical Meteorological Year 3 (TMY3) weather data for Gainesville, FL to establish a yearly baseline energy usage Chapter 4 documents the baseline mo del inputs and assumptions.

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23 Next, a proposed model based on recommended energyefficient technologies in the current literature was developed and simulated The proposed model was designed by applying perturbations, or energy efficiency measures (E E Ms), in the baseline model. Various combinations of current commercially available technologies were analyzed to measure their ability to reduce energy usage over the baseline model. A target between 50% to 70% energy savings was set in order to achieve a po tential net zero energy building. Chapter 5 documents the advanced model inputs and assumptions. A second objective wa s to seek calculate the selected designs cost effectiveness over a twenty year analysis period. Thus, percent net site energy savings as well as a twenty year total life cycle cost of the selected design were analyzed. Simulation Tool Description Designing, building, and renovating commercial buildings in order to achieve higher energy efficiency performance invol ve complex systems engin eering. T his complexity has led to a broader use of energy simulation software. eQuest, the Quick Energy Simulation Tool, is a free graphical user interface (GUI) that drives the DOE 2 simulation engine. DOE 2 is a well established building energy model ing program that has been in existence for over two decades. This program simulates the energy performance of a building using hourly time steps for all 8760 hours in a year. Weather files representing typical years are utilized to simulate climatic conditions for hundreds of locations throughout North America and the world. For many years, this program was accessed via a textbased programming language, known as the Building Description Language (BDL). This required extensive knowledge not only of buil ding science fundamentals but also of the intricacies of the DOE 2 programming methodology. The advent of GUIs such as eQuest allows the user to create building models in DOE 2 via easy to use dialog boxes and graphical displays.

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24 eQuest can be utilized in two different modes known as the Wizard mode and the Detailed mode. The Wizard mode is intended as a guide through the creation of the building energy model. Building types, geometries, internal loads, schedules, zoning and water and air side systems can all be specified within the wizards. eQuest also utilizes a dynamic default process that continually populates certain inputs with pre established default values based on the user selected inputs within the wizard. This allows the user to choose the level of detail that suits their particular needs. Models can be built early on in the schematic design phase that utilize highlevel project information and mostly rely on eQuest defaults. Then, as the project progresses, building specific information c an be entered by the user. In general, eQuest modeling follows the order of operations originally established for creating the BDL input file in DOE 2. This order falls under the categories of LOADS, SYSTEM, PLANT, and ECONOMICS. It is important to note that these categories are not immediately apparent when using the eQuest GUI. However, they are still the foundation of the DOE 2 engine that eQuest is operating and thus are important to understand. The LOADS category consists of the building geometry and the associated space and zone definitions. Within these spaces, internal loads and schedules are defined for people, lights, equipment and infiltration. Daily, weekly and annual schedules dictate when the loads are active within the spaces. The SYSTEM category is where the secondary HVAC systems are defined and are sized to meet the loads defined in the LOADS section. Each space is assigned to an air side HVAC system and the internal loads for that space are served by the system. The loads are served on an hourly basis

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25 The PLANT category consists of the primary HVAC components that provide the necessary heating and/or cooling energy to the secondary systems. Primary systems include chillers, boilers, cogeneration systems and numerous other types. The energy required to meet the loads and power the secondary systems are determined for each plant type and the cost of this energy use is then calculated in the ECONOMICS category. The ECONOMICS category allows the user to define utility rates for various fuel sources, such as electricity or natural gas. Utility rates can be simple rate structures or complex block or ratchet charges. Consumption rates as well as demand charges are also specified. The monthly and annual cost for operating the building model is then computed and reported in the results output. Development of the Small Office Building Prototype The small office prototype used for this study was based on existing floor plans for a small office building in Gainesville, FL. Figure 31 shows the floor plan of the small office building prototype. The office space consisted of two separa te suites that total 7,32 0 ft2. The building wa s rectangular shaped and 161 ft by 45 ft with an aspect ratio of 3.6. A larg er plot of the building floorplan can be found in Appendix A. The floor plan for the office was divided into seven thermal zones, each zon e being served by an air handling system These thermal zones are shown in Figure 32. A summary of zone names and corresponding characteristics are show n in Table 31. The AEDG contained a unique set of energy efficiency recommendations for each International Energy Conservation Co de (IECC)/ASHRAE climate zone. The zones were categorized by heating degree days (HDDs) and cooling degree days (CDDs), and r ange from the very hot Zone 1 to the very cold Zone 8. Subzones indicate d varying moisture conditions.

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26 Humid s ubzones were designated by the letter A, dry subzones by B, and marine subzones by C. To provide a basis for analysis, Gainesville, FL was c hosen to depict typical climate conditions in Zone 2A, which represents the hot and humid climate of the Southeas tern United States. The w eather f ile for Gainesville was obtained from the Typical Meteorological Year, version 3 data set (TMY3) which was a vailable for download via the World Wide Web at http://rredc.nrel.gov/solar/old_data/nsrdb/1991-2005/tmy3.

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27 Figure 31. Small commercial office building prototype floor plan Figure 32. Office f loor plan thermal zoning Table 3 1. Small office prototype thermal zone characteristics Zone Name Area (ft2) Floor to Ceiling Height (ft) Gross Wall Area (ft2) Window Glass Area (ft 2 ) Window/Wall Ratio Team Area 1 754 10.00 598.3 44.0 7.4% Team Area 2 7 54 10.00 343.3 44.0 12.8% Team Area 3 754 10.00 341.7 44.0 12.9% Private Offices 1,575 10.00 1,030.0 86.6 8.4% Lobby Area 939 10.00 563.3 34.6 6.1% Conference Area 1,289 10.00 583.3 69.3 11.9% Suite B 1,257 10.00 1,093.3 138.6 12.7%

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28 CHAPTER 4 BASELI NE MODEL DEVELOPMENT A number of reports and datasets were surveyed to develop typical commercial office building characteristics including the Commercial Building Energy Consumption Survey (CBECS 2003) and the DOE Commercial Building Research Benchmarks f or Commercial Buildings (Deru, Griffith et al. 2008) The modeling methods outlined in Appendix G of Standard 90.12004 (ANSI/ASHRAE/IESNA 2004a) provided the majority of baseline modeling information. Some A ssumptions used for analysis originated from t he Advanced Energy Design Guide for Small Office Bui ldings (Jarnagin et al. 2006). Details on baseline model inputs can be found in Appendix B. Building Operating Characteristics The majority of commercial office floor space surveyed by CBECS operated bet ween 40 and 60 hours a week. Typical occupancy, HVAC, lighting, miscellaneous equipment, and service hot water schedules were provided by 90.1 2004 Users Manual (ANSI/ASHRAE/IESNA 2004b). The building was assumed to follow typical office occupancy patte rns with peak occupancy occurring during normal business hours from 8 AM to 5 PM Monday through Friday. L imited occupancy was assumed to begin a t 6 AM and after business hours through midnight for janitorial functions Saturday occupancy was assumed to b e 30% of peak occupancy while Holiday and weekend occupancy were assumed to be approximately 5% of peak occupancy. The HVAC system operating schedule started prior to the beginning of normal business hours t o bring the space to the set point temperature Lighting, miscellaneous equipment, and service hot water schedules were matched to occupancy schedules with limited usage during unoccupied times. Figure 41 illustrates the schedules for occupancy, lighting, miscellaneous

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29 equipment, HVAC system, and service hot water system for a typical weekday of t he small office simulation. Further detailed building operation and load schedules can be found in Table B 1 of Appendix B. Figure 41. Weekday schedule for small office building prototype Baseline Buildin g Envelope Characteristics CBECS data showed a majority of opaque constructions consisted of mass walls, built up roof ing with insulation above deck, and slabon grade floors. T he small office building floor to ceiling height was assumed to be 10 ft with a 3 ft plenum space. Figure 42 shows an axonometric view of the building modeled in eQuest Appendix G of Standard 90.12004 required that the baseline opaque assemblies match the appropriate maximum U factors stated in Tables 5.51 through 5.5 8 of Sta ndard 90.12004. Table 5.5 2 of Standard 90.12004 contained the appropriate U factor information for climate zone 2A ( ANSI/ASHRAE/IESNA, 2004a)

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30 Figure 42. Axonometric view of the eQuest small office building model Exterior W alls Appendix G of Standa rd 90.12004 required that the baseline building model s exterior walls be s teel framed above grade walls. Appendix A of Standard 90.12004 ( ANSI/ASHRAE/IESNA, 2004a) provided further details of the specified wall assembly components including R values The exterior wall included the following layers: Exterior Air Film, R 0.17 hft2F/Btu Stucco, R 0.08 hft2F/Btu 0.625in. gypsum board, R 0.56 hft2F/Btu Steel framing at 16 in. OC with R 13 cavity insulation, R 6 hft2F/Btu 0.625in. gypsum board, R 0.56 hft2F/Btu Interior Air Film, R 0.68 hft2F/Btu The overall U value of the wall assembly was 0.124 Btu/hrft2F which met the building envelope requirements of Standard 90.12004 for climate zone 2A stated in Table 5.52 of Standard 90.12004. Roof The small office building baseline prototype consisted of a flat roof with insulation entire ly above a metal deck as required by Appendix G Roof insulation R values were set to match the

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31 maximum roof U value requirements in Table 5.52 of Standar d 90.12004 ( ANSI/ASHRAE/IESNA, 2004a) As defined in Appendix A of 90.12004, t he roof construction consisted of the following layers: Exterior Air Film R 0.17 hft2F/Btu Continuous rigid insulation, R 15 hft2F/Btu Metal deck, R 0 Interior air film heat flow up, R 0.61 hft2F/Btu The overall U value of the roof assembly was 0.063 Btu/hrft2F (0.358 W/Km2). Appendix G of Standard 90.12004 also specified that the roof surfaces be model ed with a reflectivity of 0.3. Slab On Grade Floors Appendix G of Standard 90.12004 required that the slabongrade floors match the F factor for unheated slabs stated in the same table as above. eQuest did not have an explicit F Factor input. Therefore, the slabongrade floor assembly for the small office p r ototype wa s assumed to be carpet over 6 in. concrete slab floor poured directl y onto the earth. Modeled be low the slab wa s 12 in. soil, with soil conductivity of 0.75 Btu/ h ft2 F Fenestration Statistics on the amount and distribution of windows on off ice buildings was not provided in the 2003 CBECS data. Appendix G of Standard 90.12004 required that the vertical fenestration areas modeled in the baseline equal the vertical fenestration area of the proposed design or 40% of the gross above grade wa ll area, whichever was smaller. For the baseline and proposed model, t he amount and distribution of windows was taken off of the existing architectural drawings of the building. The fenestration area equaled 7.8% of the gross above grade wall area.

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32 The fen estration U factor matched the appropriate requirements in Table 5.52 of Standard 90.12004 as well as solar heat gain coefficient (SHGC) for all orientations. The U factor assembly maximum for climate zone 2A was 1.22 Btu/hrft2F and t he SHGC equaled 0.25. eQuest did not have an input for SHGC but instead had an input for the shading coefficient (SC). Therefore in order to input the appropriate SC, the SHGC was multiplied by a factor of 0.86 ( ANSI/ASHRAE/IESNA, 2004b) The vertical glazing was mod eled as fixed and flush with the exterior wall. No shading projections and no shading devices such as blinds or shades were modeled. Air Infiltration Standard 90.1 did not specify a requirement for maximum air infiltration rate. Chapter 16, Ventilation a nd Infiltration of the 2009 Fundamentals Handbook discussed air infiltration in residential, commercial and institutional buildings. Emmerich et al. (2005) studied the energy impact through improving building envelope air tightness in U.S. commercial buildings For this analysis, the infiltration rate wa s derived from a starting point of 2.3 cfm/ft of above grade envelope surface area at 0.3 in. w.c. (Emmerich et al. 2005). This infiltration rate wa s based on testing buildings at greatly increased pre ssure difference than in normal operating conditions. An air infiltration schedule was applied to the model. The infiltration schedule assumed no infiltration occurred when the HVAC system was on, and infiltration occurred only when the HVAC system was o ff. For input into eQuest, the infiltration rate at 0.3 in. w.c. was converted to a wind driven rate with an equation developed by Gowri et al. (2009). The infiltration rate can be calculated by equation 3 1, n H s c w Bldg designU C I I 75 5 0 ) 1 (2 3 0 (3 1)

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33 Where Bldg = terrain factor 3 0 c wI = infiltration rate at 0.3. in. w.c. sC = surface pressure coefficient = air density HU = wind speed at building height n = flow exponent The resulting infiltration rate input into eQuest was calculated to be 0.2579 cfm/ft2. Internal and External Loads Internal loads included heat generated from occupants, lights, misc ellaneous equipment (plug loads). Plug loads included equipment such as computers, printers, copy machines, refrigerators, coffee makers, etc. Modeling the energy impacts of the building internal loads using the eQuest simulation program required assumptions about the building internal load intensity and operation schedules. People The 2003 CBECS data provided little information in regards to building occupancy in office buildings. ASHRAE Standard 62.12004 provided peak occupant density of 5 people per 1,000 ft2 ( ANSI/ASHRAE 2004) Occupant density was derived from existing building furniture plans and from Standard 62.12004 for areas without a specified furniture plan. The peak occupancy of the small office prototype was calculated to be 67 people. I t wa s assumed that the occ upan t activity level was 450 Btu/hr per person, including 250 Btu/hr sensible heat gain and 200 Btu/hr latent heat gain. These values represent ed the degr ee of activity in offices, moderate active office work and were derived from Table 1 of Cha pter 18 in the ASHRAE 2009 Fundamentals Handbook (ASHRAE 2009).

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34 Lighting Baseline lighting levels were determine d by the Space bySpace method and the corresponding lighting power densities in Table 9.6.1 of ASHRAE 90.1 2004 ( ANSI/ASHRAE/IESNA, 2004a) Each space was assigned a light power density based on its use. Then the overall HVAC zone lighting power density was calculated by adding the power densities of the spaces in the corresponding zone and dividing by the HVAC zone area. Table 41 shows the power ligh t densities of each HVAC zone. Table B 2 of Appendix B details lighting power density calculations. Miscellaneous Equipment (Plug Loads) Office buildings generally have plug loads pertaining to office equipment (computers, monitors, c opiers, fax machines, printers coffee makers, and beverage vending machines etc.) Plugs loads not only increase electrical usage, but also impact the sizing of the HVA C system. To determine plug load density, a breakdown plug load calculation was developed in accordance wi th ASHRAEs recommended heat gains from various office equipment and appliances (ASHRAE 2009). The amount and type of equipment was assumed based on exi sting architectural drawings. Table 4 1 shows the plug load density summary for each HVAC zone. Tabl e B 3 of Appendix B details the plug load density calculations. Table 4 1. Lighting power density and plug load density by HVAC zone Zone Name Lights (kW) Elec tric Plug and Process Loads (kW) Team Area 1 0.83 0.71 Team Area 2 0.83 0.71 Team Area 3 0. 83 0.71 Private Offices 1.51 1.71 Lobby Area 1.05 0.46 Conference Area 1.38 1.45 Suite B 1.44 1.76

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35 Baseline Building Heating, Ventilation and Air Conditioning Systems Building HVAC Operating Schedule The HVAC system oper ating schedule was based on building occupancy. The system was scheduled on two hours prior to occupancy to pre condition the space. Then the s ystem was scheduled off at 10 pm When the system was on, the fan ran continuously to supply the require d ventilation air, while the c ompressor cycled on and off to meet the buildings cooling and heating loads. During off hours, the system shut off and only cycled on when the setback thermostat control called for heating or cooling to maintain the setback temperature. A single HVAC system schedule was used for all the packaged units in the building A detailed HVAC schedule can be found in Table B 1 in Appendix B. HVAC Zoning and Heating and Cooling Thermostat Setpoint The small office building was divided into seven thermal zones a s described in Chapter 3. The HVAC systems maintained a 70F (21C) heating setpoint and 75F (24C) cooling setpoint during occupied hours. During off hours, thermostat setback control strategy was applied in the baseline prototype, assuming a 5F tempe rature setback to 65F for heating and 80F for cooling. HVAC Equipment Sizing Section G3.1.2.2 of ASHRAE 90.12004 required that sizing runs for the HVAC system were to be oversized by 15% for cooling and 25% for heating. eQuest had two methods to size t o size the HVAC equipment, annual run method and design day method. In the annual run method, the program determined the corresponding design peak heating or cooling loads using weather file data. When using the designday method, two separate design days were input, one for heating and one for cooling. The program determined the design peak loads by simulating the building for a 24hour period on each of the design days. The design peak loads were used

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36 by the subprogram for sizing HVAC equipment. This study used the designday method since it was general practice for HVAC system designers to size HVAC equipment. The design day data for the climate location of Gainesville, FL was developed based on the weather data contained in the ASHRAE 2009 Handbook of Fundamentals (ASHRAE 2009). In this data set, heating design day condition was based on the 99.6 annual percentile frequency of occurrence. The 99.6 annual percentile meant that the drybulb temperature equaled or was below the heating design conditi ons for 35 hours per year in cold conditions. Similarly, annual cooling design condition was based on drybulb temperature corresponding to 1% annual cumulative frequency of occurrence in warm conditions. A 1% value of occurrence meant that the drybulb temperature equaled or exceeded the cooling design conditions for 88 hours per year. Additionally, the range of the drybulb temperature for summer was in compliance with ASHRAE Standard 90.12004. In eQuest, design day schedules were also specified. To be consistent with general design practice for HVAC equipment sizing, the internal loads (occupancy, lights, and plug loads) were scheduled as zero on the heating design day, and as maximum level on the cooling design day. HVAC Equipment Efficiency Table G3.1.1A of ASHRAE 90.12004 Appendix G specified the required baseline HVAC system type for different building types. For this study, the small office building prototype baseline classified as a non residential building under 75,000 ft2. Accordingly, Appendix G specified for an electric heat source the baseline model be a PSZ HP (Packaged Single Zone Heat Pump). Table G3.1.1B further specified the PSZ HP to be a packaged rooftop heat pump, with constant volume fan control, direct expansion (DX) cooling, and electric heat pump heating. Appendix G also required that the fan energy be modeled separate ly from the cooling energy. eQuest called for t he cooling energy to be input as the energy input ratio (EIR) and a

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37 kW/cfm value for the fan energy for simulati on. EIR was defined simply as the inverse of the coefficient of performance (COP) (Equation 4 2). To satisfy the requirements of the modeling method and determine the EIR and kW/cfm, an iterative spreadsheet calculation was developed. COPEIR / 1 (4 2) To perform the iterative calculation, eQuest was run initially with default EIR values to size the HVAC system. From the system sizing reports, the gross cooling capacity, heating capacity, and supply air volume requirement s for the HVAC zones were input into the spreadsheet. The spreadsheet then determined the kW/cfm value as the baseline fan power as required by Appendix G divided by the supply air volume determined by eQuest for each thermal zone. From the gross cooling and heating capacities and supply air volume, the spreadsheet subtracted the fan power from the cooling power calculated from the minimum cooling and heating efficiencies required by Section 6.4 of Standard 90.12004. The kW/cfm values calculated were the n entered into eQuest and the simulation reran to calculate the gross cooling and heating capacities again. The new cooling and heating capacities replaced the old values and the spreadsheet again calculated the EIR The process was repeated until the gr oss cooling and heat capacities matched the calculated EIR. Standard 90.12004 specified HVAC equipment efficiency based on heating and cooling capacities. For packaged single zone equipment with cooling capacities less than 65,000 Btu/h cooling efficien cy was rated by the seasonal efficiency ra tio (SEER). The SEER represented the average efficiency of the system throughout the year. Cooling equipment with capacities greater than 65,000 Btu/h wa s rated by the energy efficiency ratio (EER). The EER repr esented the efficiency at a particular design condition. Similarly, for cooling capacities less than 65,000 Btu/h, the heating efficiency was rated by the heating seasonal performance factor (HSPF). The

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38 term HSPF is simi lar to SEER except it is used to s ignify the seasonal heating efficiency of heat pumps. For cooling capacities greater than 65,000 Btu/h, heating efficiency wa s rated by the COP. In order for the spreadsheet to determine the proper cooling EIR to be input into eQuest, the minimum efficien cies from Standard 90.12004 were converted i nto COP (Equation 43). T he EIR was then determine d from the COP from equation 42 above. For equipment cooling efficiency rated by SEER, a conversion from SEER to EER was determined (Wassmer and Brandemuehl 2006). Equation 4 4 converts the SEER rating into EER. 413 3 EER COP (4 3) SEER SEER EER 1008 1 0182 02 (4 4) Similarly, for equipment heating efficiencies rated by HSPF, a conversion from HSPF to C OP was calculated by equation 4 5 (Wassmer and Brandemuehl, 2006) HSPF HSPF COP 6239 0 0255 02 (4 5) HVAC System Fan Power System fan electrical power for supply, return, exhaust, and relief fans w ere calculated from equation 46 ( ANSI/ASHRAE/IESNA, 2004a), bhp e Pbhp fan 685541 1 ) ln( 2437839 01 746 (4 6) Where fan P = electric power to fan motor (Watts) bhp = brake horsepower of baseline fan motor The baseline fan brake horsepower equation is taken from Table G3.1.2.9 based on the suppl y air volume cfm and the system type. For a constant volume PSZ HP with a supply air

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39 volume less than 20,000 cfm, the baseline fan motor brake horsepower was calculated from equation 4 7 ( ANSI/ASHRAE/IESNA, 2004a) 0008625 0 ) 000 20 ( 25 17 cfm (4 7) Table 4 2 summarizes the fan energy and cooling and heating EIRs input into eQuest for the baseline model. Detailed fan power calculations as well as the EIR for cooling and heating systems from the iterative calculation method can be found in Tab le B 4 in Appendix B. Table 4 2. Fan energy, cooling EIR, and heating EIR baseline model s ummary System Supply Fan (kW/cfm) Cooling EIR Heating EIR Office 1 0.000806 0.240 0.239 Office 2 0.000811 0.242 0.240 Office 3 0.000811 0.241 0.240 Private Offic es 0.000780 0.268 0.395 Conference Area 0.000778 0.271 0.397 Lobby 0.000797 0.246 0.244 Suite B 0.000776 0.266 0.205 Outdoor Air Ventilation and Exhaust Rates Outdoor minimum ventilation air requirements were determined as required by ASHRAE Ventilation Standard 62.12004 (ANSI/ASHRAE 2004). The Ventilation Rate Procedure prescribes ventilation rates for typical occupancy categories. The prescribed ventilation rates for the small office prototype was calculated as the sum of an occupant related compo nent, expressed as volumetric airflow per person (cfm/person), and a building related component, expressed as a volumetric airflow per unit floor area (cfm/ft2). The efficiency of the air distribution system in delivering outdoor air to the breathing zone of the space was explicitly included in the rate calculation method. The people outdoor air rate Rp, area outdoor air rate Ra can be found in Table 6 1 of ASHRAE Standard 62.12004 (ANSI/ASHRAE 2004) The air distribution effectiveness Ez can be found i n Table 62 of the same standard. Equation 48

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40 (ANSI/ASHRAE 2004) calculates the required airflow in cfm for a space corrected by the zone a ir distribution effectiveness. z a z p z ozE R A R P V (4 8) Where z P = Room population (# of persons) pR = People outdoor air rate (cfm/person) zA = Room floor area (ft2) aR = Area outdoor air rate (cfm/ft2) zE = Air distribution effectiveness Required minimum exhaust rates were taken from Table 6 4 of ASHRAE Standard 90.12004 and applied to the appropriate spaces. Table 4 3 summarizes the minimum ventilation required for each zone. Det ailed ventilation and exhaust calculations are found in Table B 5 in Appendix B. Table 4 2. Ventila tion and exhaust rates by HVAC z one Zone Name Required Ventilation (cfm) Exhaust (cfm) Team Area 1 81.00 Team Area 2 81.00 Team Area 3 81.00 Priva te Offices 107.00 87.00 Lobby Area 77.00 100.00 Conference Area 181.00 26.00 Suite B 150.00 76.00 Economizer Use Appendix G of Standard 90.1 specified economizer use based on system type and climate location. For climate location zone 2A, an economiz er was not required to be modeled in the energy simulation.

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41 Service Hot Water System The baseline service hot water system for the small office building was assumed as an electric storage water heater. The equipment met the minimum efficiency requirements under ASHRAE Standard 90.12004. The hot water supply temperature was assumed to be 120F. In order to estimate the energy performance of a service hot water heater with a storage tank, eQuest required the user to define the following key input variables as operating parameters: Rated storage tank volume Peak hot water flow rate Hot water use schedule Maximum heater capacity Standby heat loss coefficient (UA) Heater thermal efficiency Hot Water Usage The typical hot water use for office buildings was ass umed to be 1 gallon per person per day, derived from Chapter 49, Service Water Heating in ASHRAE Applications Handbook (ASHRAE 2007). Based on the maximum occupancy schedule, this resulted in a daily maximum hot water consumption of 67 gallons per day f or the small office building prototype. To determine the peak water flow rate in gpm, the daily hot water consumption was divided by the operating hours for the day, which was 8 full load hours. Thus, the peak hot water flow rate was calculated as 0.447 gpm. Storage Tank Size The water heat storage tank volume was sized based on the methodology described in the 2007 ASHRAE Applications Handbook (ASHRAE 2007). For a usable storage capacity of 0.6 gallons per person for 67 people, the total usable storage capacity was 40 gallons. The actually

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42 storage tank size was increased by 25% to compensate for unusable hot water, which was calculated to be a total storage capacity of 50 gallons. Input Power and Standby Heat Loss Coefficient For electric water heater s, the minimum efficiency required by ASHRAE Standard 90.12004 was expressed as the Ener gy Factor (EF). Equation 4 9 calculates the EF f or an electric water heater as V EF 00132 0 93 0 (4 9) Where V = Tank storage volume Water heater characteristics were obtained from Energy Efficiency Standards for Consumer Products: Residential Water Heaters (DOE 2000). The document modeled and analyzed energy efficiency features in electric and gas water heaters. For a 50 gallon electric water heater, the baseline model had an energy recovery factor of 0.86, which met the minimum energy factor in Standard 90.12004. The baseline model also had a recovery efficiency of 98% and a heat loss coefficient UA of 3.64 Btu/hrF. Two heating elements were modeled with a power consumption of 4.50 kW each and 100% efficiency.

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43 C H APTER 5 PROPOSED MODEL DEVEL OPMENT The proposed office building model was devel oped by modifying the baseline model with energy efficiency measures (EE Ms). The measures aimed to reduce the internal heat loads and energy usage of the baseline model and then meet the heating and cooling requirements of the reduced loads model through more efficient HVAC strategies. Two rules were developed to guide the identification of energy efficiency measures. First, the EE Ms had to be based on technologies that were commercially ava ilable Also, eQuest ha d to have been capable of model ing the EE Ms directly or via an equivalent approach. Together, the EE Ms identified had to have been able to achieve a whole building energy savings ranging from 50% to 70%. After such savings were achieved, an on site photovoltaic system was sized to meet the reduced loads models annual energy needs. The EEM concepts were developed from the sources discussed in Chapter 2. All EE Ms were grouped into the following five categories: Building envelope measures Lighting measures Plug load measures HVAC measures Service water heating measures Although any combination of EE Ms could achieve the same goal it was not the intent of this study to find the optimum combination. This section describes the EE Ms that were implemented in the proposed model that demonstrated and met the criteria for energy savings in eQuest.

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44 Building Envelope Energy Efficiency M easures Enhanced Wall Assembly Improving the thermal performance of the wall assembly was explored to reduce heating and cooling loads. A high performing wall assembly kept heat inside the building during the heating season and kept heat outside of the building during the cooling season. In order to determine the optimal amount of additional insulation to add to the wall assembly, the U value of the wall assembly was increased incrementally based on the effective assembly U values found in Appendix A of 90.12004. The energy savings gained by the added insulation was correlated to its U value. Figure 51 shows energy savings correlated with increasing R value. Figure 51. Correlation between annual building energy consumption and added wall insulati on. For the proposed mode, R 20 insulation was added as additional insulation to the baseline model wall assembly. Further measures were taken to improve the performance of the wall assembly by reducing infiltration. An air barrier was added to the wall assembly to reduce infiltration of the baseline model. Emmerich et al. (2004) determined an infiltration rate of 0.24 cfm/ft2 at 0.3 in. w.c. was a level of airtightness achievable through good construction practice. Thus, 0.24 cfm/ft2 was selected as th e infiltration rate for the proposed model. For input into eQuest, the infiltration rate was converted, as discussed in Chapter 4, to 0.0269 cfm/ft2.

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45 Cool Roof To reduce the cooling load in a hot and humid climate, a cool roof was added to the building roof assembly. By reflecting solar energy, a cool roof reduced the require size of the HVAC system. The modeled cool roof for the advanced design was a light colored reflective roof membrane with a solar reflectance of 0.7. Conversely, the modeled roof for the baseline model had a solar reflectance of 0.3. Furthermore, additional insulation was explored for added energy savings. However, a dding additional roof insulation resulted in minimal energy savings. The roof assembly insulation remained the sam e as the baseline model. High Performance Windows and Shading Devices The advanced model maintained the same window area as the baseline mode, but window constructions were improved in terms of U factor and SHGC value. Double pane low emissivity glass was modeled in the advanced along with permanent shading devices. The argon filled double pane windows had a center of glass U factor of 0.24 Btu/hrft2F, a SHGC of 0.43 and a visual transmittance of 0.7. Window overhangs were implemented as a passive solar design strategy for southoriented facades. Overhangs limited the solar gain during the summer months while allowing solar gain during the winter months. The overhangs were designed to completely shade the southoriented fenestrations during the sum mer solstice, wh e re the sun was at its highest during the year

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46 Figure 52. Proposed model with the addition of window overhangs on the south faade. Lighting Energy Conservation Measures Reduced Interior Lighting Power After a review of the literature it was determined that T8 lamps were the more dominate fluorescent fixture type than T5 lamps. Although solid state lighting provided far better energy savings compared to fluorescent lamps, the technology was not yet marketable or cost effective (Kenda ll, 2001) To model the light ing power required by T8 lamps, the number of lamp fixtures per room were estimated based on existing architectural drawings. The T8 lamps were assumed to consume 32 watts per lamp. Then the total lamp wa ttage was calculated per zone. Occupancy Sensor Control Appendix G of ASHRAE Standard 90.12004 allowed for a 10% power adjustment for occupancy sensor control for the small office building proposed model. Occupancy sensors were modeled in all occupied spaces. To model o c cupancy sensor co ntrol, the lighting power for each area with occupancy sensor control was reduced by 10%. Table 5 1 compares the lighting power

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47 of the proposed model with occupancy control and T8 lamps versus the lighting power of the baseline model. Ta ble 51. Lighting power of baseline model and proposed m odel HVAC Zones Baseline Model Total Watts (kW) Proposed Model Total Watts (kW) Team Area 1 0.8290 0.5184 Team Area 2 0.8290 0.5184 Team Area 3 0.8290 0.5184 Private Office Area 1.5134 1.5840 Lo bby Area 1.0546 0.7488 Conference Area 1.3840 1.2096 Suite B 1.4425 1.1520 Total 7.8815 6.2496 Daylight Harvesting Daylight sensors were modeled in perimeter spaces with automatic dimming controls to take advantage of available daylight to reduce electrical energy consumption while maintaining desired levels of illumination. Interior shading devices were also modeled for the advanced model. The baseline model did not include interior shading devices as dictated by Appendix G of Standard 90.12004. Interior shading devices were closed when the glare index was above the set point of 22, typical for offices. The glare index was the ratio of window luminance to the average surrounding surface luminance within the view field. Daylight sensors were placed two thirds the depth of the perimeter spaces and half the length inward at a height of 2.5 ft. All of the ambient lighting in the spaces zone was dimmed in response to daylight. The dimming control system had an illuminance setpoint of 50 footcandles, typical for desk work. Dimming controls were continuous which could dim down to 10% of maximum light output with a corresponding 10% of maximum power input. Table C 1 of Appendix C shows further details in the proposed lighting model calculations.

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48 Miscellaneous Equipment (Plug Loads) Measures According to the CBECS survey, plug loads in office buildings accounted for 25% of total onsite energy consumption. In the baseline model, plug loads accounted for 24% of total building energy use. Howeve r, as other building systems became more efficient, that percentage became even higher. P lug loads affected the cooling loads and heating loads of the building due to internal heat gains. In order to reduce the plug load energy usage, Energy Star rated equipment were implemented in the advanced model. A savings calculator provided by the Energy Star website for each equipment category (computers, monitors, copy machines, fax machines, water coolers, and refrigerators) was used to calculate the energy savings compared with noncompliant Energy Star equipment (EPA, 2009) The percentage savings was used as a savings factor to calculate the new plug load. To further reduce plug load energy usage, a strategy of shifting from using energy intensive desktop computers to energy efficient laptop computers was implemented. All desktops in the baseline case were changed to laptop computers. Table 5 2 compares the baseline plug loads to the new calculated advanced model plug loads. Table 5 3 shows the percent r eduction in equipment power to Energy Star labeled rated equipment. Detailed plug load calculations can be found in Table C 2 of Appendix C. Table 5 2. Plug load of baseline model and proposed m odel HVAC Zone Baseline Model Plug Load (kW) Proposed Model Plug Load (kW) Team Area 1 0.707 0.384 Team Area 2 0.707 0.384 Team Area 3 0.707 0.384 Private Office Area 1.706 1.369 Lobby Area 0.458 0.242 Conference Area 1.452 1.049 Suite B 1.76 1.375 Total 7.497 5.187

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49 Table 5 3. Percent r eduction of Energy Star e quipment Office Equipment Inventory Peak Power (W) Energy Reduction Energy Star Peak Power Computers servers 65 33% 43.55 Computers desktop 65 33% 43.55 Computers laptop 40 33% 26.8 Monitors LCD 36 22% 28.08 Laser printer desktop 110 3 3% 73.37 Copy machine (large) 1100 7% 1023 Multifunction 135 50% 67.5 Fax machine 20 50% 10 Water cooler 350 45% 192.5 Refrigerator 76 20% 60.8 Vending machine snack 275 53% 129.25 HVAC System Measures There were numerous types of HVAC systems an d strategies to reduce energy consumption in the advanced model. For this study, a geothermal ground source heat pump system serving each zone was modeled. In addition to the geothermal heat pump system, a dedicated outdoor air system (DOAS) with energy recovery ventilation (ERV) was modeled to provide ventilation air to the building Geothermal Heat Pump System A geothermal ground source heat pump system was used in each thermal zone to satisfy the heating and cooling loads. Geothermal heat pumps (G HPs) have been proven a capable technology to reduce energy usage and peak demand in buildings (ASHRAE, 2006) Hundreds of millions of dollars were spent annually on more expensive renewable energy technologies than GHPs, such as power generation from sol ar, wind, geothermal, and biomass resources, as well as on strategies to reduce our dependence on foreign oil (Hughes, 2008) Aggressive installation of GHPs could avoid the need to build 91 to 105 GW of electricity generation capacity, or 42 to 48 perce nt of the 218 GW of net new capacity additions projected to be needed

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50 nationwi de by 2030 (Hughes 2008). $33 to 38 billion annually in reduced utility bills at 2006 rates could be achieved through aggressive GHP installation (Hughes, 2008) Over the last several decades GHP systems have gradually improved and been incorporated into the systems for heating, cooling, and water heating equipment for U.S. buildings. The GHP system for this study utilize d the natural properties of the earth to provide heat ing and cooling t o the advanced model building. The system design was a vertical closed loop system, having a dedicated fluid loop that wa s circulated through the ground in order to exchange heat Earth temperature had a significant effect on the performanc e of the GHP system The suitability of the earth as a heat so urce or sink for a GCHP system was greatly influenced by the soil thermal characteristics. For this study, several assumptions about the soil thermal properties were made. The ground soils t hermal diffusivity was assumed to be 0.030 ft2/hr and thermal conductivity to be 1.270 Btu/hftF. The earths undisturbed temperature was estimated using a groundwater temperature profile map of the United States. For Gainesville, FL, the undisturbed g round temperature was assumed to be 72F. The most important factor to the design and operation of the GHP system wa s the rate of heat transfer bet ween the working fluid in the G HP and the surrounding s oil. Heat transfer between the G HP and its surrounding soil wa s rather complicated and difficult to model fo r the purpose of sizing G HPs or for energy analysis of the system. S tructural and geome trical configuration of the system ground temperature distribution, soil moisture cont ent and its thermal prope rties, groundwater movement, and possible freezing and thawing in soil were among the many factors that influence d performance Models of varying complexity have been presented for practical applications in design and performance prediction of G HPs. Mos t of the

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51 design and simulation programs require monthly building loads and provide d monthly average ground loop entering and exiting temperatures of the heat transfer fluid. A good number of the analytical design approaches were based on Kelvins line sour ce theory or its derivations by Ingersoll et al. (Bose et al. 1985 ) The l ine source approach approximated the ground loop borehole as an infinitely long line with radial heat flow in a uniform, continuous infinite media The expression is : ) ( 2 2' 2 '2x I k Q d e k Q T Ts t r s o (5 1) W here 'Q = Heat input, to line source, Btu/h ft (W/m) T = Temperature at distance r, F (C) o T = Undisturbed earth temperature, F (C) r = Radial distance to line source, ft (m) t = Time, hours = Variable of integration ) ( x I = Values of the integral To estimate the length of tube required for the ground heat exchanger, t he required ground heat exchanger length calculated based on heating requirements HL is: min min ,1ewt g h s p h h heat d HT T F R R COP COP q L (5 2) W here heat dq, = Design heating load hCOP = Design heating coefficient of performance of the heat pump pR = Pipe thermal resistance sR = Soil/field thermal resistance hF = GHX part load factor for heating min gT = Minimum undisturbed ground temperature min ewtT = Minimum design entering water temperature at the heat pump A similar equation estimated the required length CL based on cooling requirements:

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52 max max ,1g ewt c s p c c cool d CT T F R R COP COP q L ( 53) W here cool dq, = Design cooling load cCOP = Design cooling coefficient of performance of the heat pump cF = GHX part load factor for cooling max gT = Maximum undisturbed ground temperature max` ewtT = Maximum design entering water temperature at the heat pump The load factor wa s defined as the ratio of the heat pump run hours divided by the time period. A run fraction of 50% would represent a heat pump run time of 360 hours in a 720 hour month. The subscript C or H specified cooling or heating. Equations 5 2 and 56 were simplifications and do not take into consideration long term thermal balances that could alter the soil temperat ure field over a period of many years. To accurately account of longterm thermal soil temperature balance, GS2000 v3, a ground heat exchanger sizing software developed by Caneta Research, Inc. was utilized to calculate the heat exchanger size required f or the advanced model. The ground heat exchanger system design was composed of 20 boreholes in a 4 x 5 borehole field configuration spaced 20 ft apart. Each borehole contained high density polyethylen e (HDPE) single U tubes Boreholes were 6 in. in dia meter with U tubes sized at in. nominal diameter. Each borehole depth was 212 ft. The holes were backfilled with grout ing have a thermal conductivity of 0.85 Btu/hftF Grouting wa s required to prevent contamination of the ground water and give bett er thermal contact between the pipe and the ground. The land area required by the heat exc hanger field was 4,800 sq. ft.

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53 Heat pump efficiencies of the geothermal system were based on geothermal heat pumps manufactured by ClimateMaster Inc. Table 5 4 li sts the characteristics of the selected geothermal heat pumps. Table 5 4. Performance characteristics of geothermal heat p umps System Nominal Cap (Tons) Cooling Capacity (Btu/hr) Heating Capacity (Btu/hr) Cooling Effiency (EER) Heating Efficiency (COP) Office 1 1 12,300 9,500 18.1 5.3 Office 2 1 12,300 9,500 18.1 5.3 Office 3 1 12,300 9,500 18.1 5.3 Private Offices 2 26,000 19,400 20.0 5.0 Conference Area 3 34,600 25,800 20.2 5.9 Lobby 1 12,300 9,500 18.1 5.3 Suite B 3 34,600 25,800 20.2 5.9 Ded icated Outdoor Air System A dedicated outdoor air system ( DOAS ) was used to condition and deliver the required minimum outdoor ventilation air to each individual zone. Outdoor ventilation airflow for the proposed model was equivalent to the baseline model The DOAS setup consisted of an enthalpy wheel, a cooling coil, a heating coil and a supply fan. The DOAS allowed for a centralized location of outdoor air intake and the use of a single ERV to pretreat incom ing outdoor air. For the advanced model, the DOAS fans were run continuously to meet outdoor air requirements while the zone heat pump fans were cycled on and off to meet the loads of its dedicated zone. Contrarily the baseline model had to have all its fans run continuously to meet outside air re quirements. The DOAS supply air temperature was maintained at 55F (12.8C). The system provided the minimum outdoor ventilation air required when the building was occupied. The ERV reclaimed energy from exhaust airflows to precondition the outdoor vent ilation air. Both heat and moisture were able to be transferred between exhaust air and outdoor air streams. The

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54 sensible and latent effectiveness of the energy recovery was 76 and 74, respectively. The cooling efficiency of the DOAS was assumed to be 14.0 SEER. Service Water Heating Measures Service water heating in office buildings used little energy in the overall total energy usage. In order to heat service hot water in the advanced model, the task was transferred from a traditional electric water heater to the geothermal heat pump system. This was done with the addition of a desuperheater to the geothermal heat pump system. eQuest did not have the capability to explicitly model a desuperheater. Instead, the hot water demand was modeled as a process load on the circulation loop of the geothermal heat pump system and was to be able to meet the annual hot water demands of the building. On Site Energy Generation In order to meet the onsite energy needs of the advanced mode, a rooftop photovoltaic system was modeled to provide the yearly electrical energy needs of the office building. PV Watts v2.0, a web based calculator provided by the National Renewable Energy Labor atory, calculated the yearly electrical energy production of a photovoltaic syst em in Gainesville, FL A holistic approach was used to size the photovoltaic system. An initial system size was input into the calculator. Then the system size was increased incrementally until the electrical energy production for the year satisfied the office buildings energy needs. The photovoltaic system size for the office building was initially chosen to be 40 kW. Facing due south and tilted to the buildings latitude, the system produced 52,184 kWh of electrical energy per year, with a DC to AC d e rate factor of 0.77. The results of the photovoltaic system simulation are found in Table 5 5.

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55 PV Watts had a built in PV system efficiency of approximately 10%. Higher PV system efficiencies for several sized PV system s were calculated ranging from 10% to 25% in 5% increments. The results of the PV system efficiency calculations are shown in Figure 53. Table 5 5. PV Watts v2.0 PV simulation r esults Month Solar Radiation (kWh/m 2 /day) AC Energy (kWh) 1 4.33 3892 2 4.76 3856 3 5.6 4954 4 6.14 5179 5 5.79 4879 6 5.43 4391 7 5.43 4560 8 5.28 4408 9 5.23 4282 10 5.13 4426 11 4.4 3752 12 4.03 3605 Year 5.13 52184 Figure 53. PV system efficiency range and output

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56 CHAPTER 6 SIMULATIO N RESULTS Baseline Model Energy Simulation Results The bas eline model of a small office building located in Gainesville, FL wa s modeled to meet the requirements of the ASHRAE 90.12004 Appendix G Performance Rating Method. The baseline building contained many of the same features as the proposed model with the exception that building envelope, HVAC system parameters and other components that were targeted for energy saving measures. This allowed for a reliable comparison of the energy use bet ween the two models and provided a way to accurately credit energy saving features in the proposed building. It wa s important to remember that some of the energy uses and building features in computer energy models will not exactly mirror reallife conditions. However, the purpose of the AS HRAE Performance Rating Method w a s to evaluate the impact of building and system design choices on energy consumption. Table 6 1 shows the annual energy enduse breakdown for the small office baseline model. Appendix G of Standard 90.12004 required the building be simulated in its original orientation and then rotated 90, 180, and 270 degrees. The results of the simulations were then averaged. The building had an energy use intensity (EUI) of 56.3 kBtu/ft2. Note that this figure represented site energy use and does not account for losses due to transmission and production at the source According to the 2003 CBECS survey, t he average EUI for small office buildings defined as having floor areas of approximately 5,500 ft2, was 79.9 kBtu/ft2. F igure 61 shows a graphical view of the en ergy enduses for the small office baseline model. Fan energy use accounted for 28% of the total electricity cons umption. The next largest consumers of electricity were miscellaneous equipmen t (plug loads) cooling systems and lighting which accounted f or 24%, 20% and 18% of total electricity consumption, respectively.

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57 Heating systems made up the next largest portion of electricity use at 6 %. The rest of the small office energy consumption profile was made up of heating hot water and supplemental heat pump energy, w hich accounted for a small fraction of total electrical energy consumption. Table 6 1. Annual energy enduse breakdown of the baseline m odel Components Electricity (kWh) Total (kBtu) Space Cool 23,543 80,351 Space Heat 6,745 23,021 HP Supp. 315 1,075 Hot Water 5,720 19,522 Vent. Fans 33,495 114,318 Pumps & Aux. 200 683 Misc. Equip. 28,550 97,441 Area Lights 22,280 76,042 Total 120,848 412,453 Figure 61. Annual energy enduse percentage of b aseline m odel The annual utili ty cost for the small office baseline model was $8,459. Electricity costs made up 100% of the baseline models utility costs. The electricity rate was based on the local utility providers rate of $0.07/kWh. No demand charges or time of day charges were applied to the baseline model. Appendix D details the energy use calculations of the small office baseline model.

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58 Advanced Model Energy Simulation Results The small office building proposed m odel represented the energy conservation measures outlined in Chapter 5. Table 6 2 shows the annual energy usage by enduse for the proposed model The proposed building had an annual energy use intensity (EUI) of 23.4 kBtu/ft2. Without onsite energy g eneration, this represented a 59 % reduction in energy use from the baseline building. Annual utility costs for the proposed model without t he photovoltaic system were $3,506. With the addition of a 40 kW photovoltaic system, the percentage i mprovement in energy use was 102 % meaning the proposed model produced mor e energy than was necessary and eliminated all annual utility costs. The total carb on dioxide emissions due to the small office building we re reduced by 102% from the baseline to the proposed design. This represented an avoidance of approximately 165,000 lbs of CO2 emissions and was an important metric in the growing movement to reduce the carbon footprint of buildings and institutions worldwide. Higher efficiency PV systems could allow for a smaller PV system, reducing the footprint of the system on the roof of the building. From the onsite energy generation analysis performed, a 30 kW PV system with a 15% efficiency or a 20 kW PV system with a 20% efficiency could also generate enough electricity to satisfy the proposed small office buildings energy needs. Figure 62 shows the breakdown of total energy consumption in the proposed model. Space cooling experienced a 72% improvement in energy use, pri marily due to the reduction internal loads, improved envelope characteristics, and use of more efficient HVAC system Along with space cooling, the space heating energy was reduced by 84%. With lower cooling and heating loads, fan energy improved by 81%. Interior lighting improved by 50% and miscellaneous equipment (plug loads) improved by 23%. With incr eased energy conservation measures in building systems, total energy consumption for the proposed model was now

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59 dominated by miscellaneous (plug loads) equipment and interior lighting energy, constituting 44% and 22%, respectively, of total energy consumpt ion. Space cooling, space heating, fan energy, and pump energy comprised 13%, 2%, 13%, and 6% of total building energy consumption, respectively. Table 6 2. Annual energy enduse breakdown of the proposed m odel Components Electricity (kWh) Electricity (k Btu) Space Cool 6,600 22,526 Space Heat 1,050 3,584 HP Supp. 0 0 Hot Water 0 0 Vent. Fans 6,430 21,946 Pumps & Aux. 2,910 9,932 Misc. Equip. 22,010 75,120 Area Lights 11,080 37,816 Total 50,080 170,923 Figure 62. Annual enduse percentage of proposed m odel

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60 CHAPTER 7 COST ANALYSIS A life cycle cost (LCC) analysis was performed to determine the economics of additional costs incurred by the proposed package of energy efficiency measures versus the baseline. The Building Life Cycle Cost program developed and provided by the National Institute of Standards and Technology (NIST) was utilized to calcula te life cycle cost. LCC estimates were calculated in present value dollars, where all futures costs were discounted to a present value as o f the base date and summed to arrive at the total lifecycle cost of the proposed package. The analysis assumed a project life of 20 years and a 3.0% real discount rate. Operations and maintenance costs were not included into the LCC estimates. Energy e scalation rates were based on energy price projections provided by DOEs Energy Information Administration (EIA). Cost estimates were based on several sources. One of the most widely accepted sources of construction cost information was the RS Means Guid e (2009) which was utilized for much of the cost estimating. Other sources utilized for cost information were from published reports and online information. Unfortunately, conflicting sources of information yielded dramatic differences in cost. The tot al building cost was estimated using data from the 2009 RS Means Building Construction Guide. For the small office building in this study, the total construction cost estimate was calculated to be $118.80/ft2, for a total building construction cost of $869,616. The general approach was to take a conservative estimate when confronted with various or vague cost estimates. Details in the cost estimate calculations are found in Appendix F. Two main cost scenarios were explored for this study. The first cost scenario explored costs of only the proposed package of EEMs that were analyzed in this study, while the second cost scenario determined the costs of a solar PV system A baseline LCC established the LCC of the baseline case, where no upfront costs were incurred. The calculated LCC of the b aseline

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61 scenario was $138,713. For the case of scenarios with a PV system, it was assumed the selected PV system generated all the buildings annual energy requirements. No federal or state tax credits were added to the cost calculations. The first cost scenario calculated the LCC of the proposed energy savings package without the addition of the PV system. Before the addition of a PV system, the additional cost of the proposed E EM package was 5.3 % of the total b uild ing cost, with a LCC of $103,172. Compared to the baseline, the proposed package saved $35,541 over the twenty year study period. The second cost scenario added the cost of a PV system that generated all the proposed small office buildings needed energy for the year. The cost of PV installation was assumed over a range of costs, ranging from $10/W to $2/W in $2/W increments. The PV systems that were discussed earlier were selected for cost analysis. Table 7 1 and Table 72 summarize the cost calculations.

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62 Table 7 1. Summary of proposed package LCC a nalysis Package Additional Cost % of Building Cost Annual Energy Savings LCC Simple Payback Baseline $ $ $ 138,713 Package w/o PV $ 45,690 5.3% $ 4,953 $ 103,172 9.22 Table 7 2. Summary of PV system LCC analysis (including proposed package costs) Package Additional Cost % of Building Cost Annual Energy Savings LCC Simple Payback Baseline $ $ $ 138,713 40 kW (10% efficient) ($10/W) $ 444,842 54% $ 8,206 $ 444,842 54.21 ($8/W) $ 364,842 42% $ 8,206 $ 364,842 44.46 ($6/W) $ 284,842 33% $ 8,206 $ 284,842 34.71 ($4/W) $ 204,842 24% $ 8,206 $ 204,842 24.96 ($2/W) $ 124,842 14% $ 8,206 $ 124,842 15.21 30 kW (15% effici ent) ( $10/W) $ 344,842 40% $ 8,206 $ 344,842 42.02 ($8/W) $ 284,842 33% $ 8,206 $ 284,842 34.71 ($6/W) $ 224,842 26% $ 8,206 $ 224,842 27.40 ($4/W) $ 164,842 19% $ 8,206 $ 164,842 20.09 ($2/W) $ 104,842 12% $ 8 ,206 $ 104,842 12.78 20 kW (20% efficient) ($10/W) $ 244,842 28% $ 8,206 $ 244,842 29.84 ($8/W) $ 204,842 24% $ 8,206 $ 204,842 24.96 ($6/W) $ 120,000 14% $ 8,206 $ 120,000 14.62 ($4/W) $ 80,000 9% $ 8,206 $ 80,000 9.75 ($2/W) $ 40,000 5% $ 8,206 $ 40,000 4.87

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63 CHAPTER 8 CONCLUSIONS Design and Energy Analysis The design and energy use analysis of a small office building located in the hot and humid climate of Gainesville, Florida was performed for this study. A baseline of building energy performance was established based on the Performance Rating Method established by Appendix G in ASHRAE Standard 90.1. To reduce energy consumption of the baseline office building, energy efficiency measures (EEMs) were applied to the baseline design and the resulting energy savings were determined from energy modeling analysis with eQuest utilizing the DOE 2 engine. With an energy savings target between 50% and 75% over the baseline energy savings gained by the proposed package of EEMs were 59% over the baseline small office building. The remaining annual energy needs of the proposed office building were met by the addition of a 40 kW rooftop PV system. D etermining which EEMs were implement ed was based on p ublished design guides as well as research papers on building energy saving methods. EEMs, however, were limited to currently market available products as well as building form No attempt was made to redesign the architecture of the building envelope. Although some measures may have been a better choice from an energy savings standpoint, many of these measures were still in the research stage and not as yet widely accepted by industry. Modeling EEMs was a simple matter of implementing the EEM into the model and analyzing its energy savings. Although each individual EEM had varying degrees of energy savings, any combination of EEMs may have saved an equal amount of energy. Analysis of EEMs was also limited by the energy modeling program itself. Availab le e nergy modeling programs were limited by their ability to model building technologies. Usually,

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64 the latest technologies would not be available in modeling software. Though, from experience, it seemed eQuest was gaining popularity over established proprietary software, such as Trane Trace or Carrier HAP, within the growing field of energy modeling due to its easy to use graphical interface and cost free availability to the public Life Cycle Cost Analysis After a proposed package of EEMs was established an economic analysis was performed to determine additional costs required by the chosen energy efficiency measures and life cycle cost (LCC). Two scenarios explored cost implications with and without a PV system. The proposed EEM package with a GSHP system had a LCC than the baseline and was considered cost effective. Addition of a PV system cost increased LCC dramatically. A few PV systems had an attractive LCC, but only when the cost of PV was at $2/W. However, with a high efficiency PV system, suc h as the 20 kW, 20% efficient PV system, PV system costs of $6/W and $4/W were cost effective. The addition of federal and state tax credits given to solar PV systems as well as GSHP systems made the LCC of the analyzed systems even more attractive. Exce ss electricity generated from the PV system was not considered, however, could be more favorable if the right economics were in place to sell excess electricity where the building was located. If energy reduction goals were met above and beyond the achiev ed 59% energy savings, the size of and, consequently, cost of the PV system would be reduced even further making the path to net zero more cost effective. Recommendations for Future Research The goal to achieve cost effective net zero energy buildings is hindered by cost itself. However, finding the optimal cost effective energy saving strategy for a particular location can be a daunting task. Research into automated optimal designs through energy modeling simulations can p rovide a deeper understanding o f the trade offs between EEMs. Automated

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65 optimization tools can evaluat e individual energy measures and determin e the marginal benefit and cost of each measure in various combinations of measures for any particular location. Automated optimization would require increased computing power, but would likely be a welcome design tool for the energy modeler. O ther potential EEMs are worth considering and some alr eady evaluated could be further refined. The new and refined measures have t he potential to achieve the goal of net zero in a more cost effective manner or to achieve even more onsite energy savings. Research into potential EEMs could include: Building form and orientation Determine the range of savings for different configurations including options for more constrained sites. Daylight harvesting Investigate most cost effective ways to provide toplighting and sidelighting. Window shading Consider advanced window shading measures for better control of cooling loads while supporting daylighting. Window area Investigate optimal window areas for the combined impact on heating, cooling and daylighting. HVAC controls HVAC control strategies that control heating and cooling setpoints based on occupancy Alternative radiant/convective systems Syste ms for office buildings include chilled ceiling panels, chilled beam, and radiant floors Determine if reasonable opportunities exist for smaller buildings to incorporate chillers and boilers.

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66 APPENDIX A SMALL OFFICE FLOORPLAN AND ROOM DESCRIPT IONS

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67 T able A 1. Small office building room descriptions Room Name Room Area ( ft 2 ) Room Number HVAC Zone Group Waiting/Reception 352 A 01 Lobby Area Office 282 A 02 Lobby Area Workroom 103 A 03 Lobby Area File Room 255 A 04 Conference Area Office 113 A 05 Conference Area Conference 354 A 06 Conference Area Conference 166 A 07 Conference Area Kitchenette 84 A 08 Conference Area HVAC 35 A -09 Conference Area Corridor 118 A -10 Conference Area Supplies 13 A 11 Lobby Area Men's Room 43 A 12 Lobby Area Wom en's Room 42 A 13 Lobby Area Men's Room 41 A 14 Lobby Area Women's Room 64 A 15 Lobby Area Team Area 754 A 16 Team Area 1 Team Area 754 A 17 Team Area 2 Team Area 754 A 18 Team Area 3 Partner Office 188 A 19 Private Offices Office 158 A 20 Private O ffices Partner Office 185 A 21 Private Offices Copy/Plotter 172 A 22 Private Offices Telecom 31 A 23 Private Offices Partner Office 185 A 24 Private Offices Partner Office 188 A 25 Private Offices Corridor 453 A 26 Private Offices Corridor 163 A 27 Conference Area HVAC 14 A 28 Private Offices Waiting/Reception 182 B 01 Suite B Conference 177 B 02 Suite B Office 131 B 03 Suite B Office 131 B 04 Suite B Office 179 B 05 Suite B Office 165 B 06 Suite B Copy Room 102 B 07 Suite B Toilet 102 B 08 Suite B HVAC 10 B 09 Suite B Corridor 78 B 10 Suite B Total 7,320 SF

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68 APPENDIX B BASELINE MODE INPUTS Table B 1. Building l oad s chedule s Schedule Type Day of Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Lighting Fraction WD 0.05 0.05 0.05 0.05 0.05 0. 1 0.1 0.3 0.9 0.9 0.9 0.9 0.8 0.9 0.9 Sat 0.05 0.05 0.05 0.05 0.05 0.05 0.1 0.1 0.3 0.3 0.3 0.3 0.15 0.15 0.15 Sun 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 CDD 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Equipment Fraction WD 0.05 0.05 0.05 0.05 0.05 0.1 0.1 0.3 0.9 0.9 0.9 0.9 0.8 0.9 0.9 Sat 0.05 0.05 0.05 0.05 0.05 0.05 0.1 0.1 0.3 0.3 0.3 0.3 0.15 0.15 0.15 Sun 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 CDD 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Occupancy Fraction WD 0 0 0 0 0 0 0.1 0.2 0.95 0.95 0.95 0.95 0.5 0.95 0.95 Sat 0 0 0 0 0 0 0.1 0.1 0.3 0.3 0.3 0.3 0.1 0.1 0.1 Sun 0 0 0 0 0 0 0.05 0. 05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 CDD 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Infiltration Fraction WD 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 Sat 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 Sun 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 C DD 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 HDD 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

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69 Table B 1. Continued Schedule Type Day of Week 16 17 18 19 20 21 22 23 24 Lighting Fraction WD 0.9 0.9 0.5 0.3 0.3 0.2 0.2 0.1 0.05 Sat 0.15 0.15 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Sun 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 CDD 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 Equipment Fraction WD 0.9 0.9 0.5 0.3 0.3 0.2 0.2 0.1 0.05 Sat 0.15 0.15 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Sun 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 CDD 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 Occupancy Fraction WD 0.95 0.95 0.3 0.1 0.1 0.1 0.1 0.05 0.05 Sat 0.1 0.1 0.05 0.05 0 0 0 0 0 Sun 0.05 0.05 0.05 0.05 0 0 0 0 0 CDD 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 Infiltration Fraction WD 0 0 0 0 0 0 0 1 1 Sat 0 0 0 1 1 1 1 1 1 Sun 1 1 1 1 1 1 1 1 1 CDD 1 1 1 1 1 1 1 1 1 HDD 1 1 1 1 1 1 1 1 1

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70 Table B 1. Continued Schedule Type Day of Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 DHW Fraction WD 0.05 0.05 0.05 0.05 0.05 0.08 0.07 0.19 0.35 0.38 0.39 0.47 0.57 0.54 0.34 Sat 0.05 0.05 0.05 0.05 0.05 0.08 0.07 0.11 0.15 0.21 0.19 0.23 0.2 0.19 0.15 Sun 0.04 0.04 0.04 0.04 0.04 0.07 0.04 0.04 0.04 0.04 0.04 0.06 0.06 0.09 0.0 6 CDD 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 HVAC On/Off WD 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 Sat 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 Sun 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Heating Temp WD 60 60 60 60 60 60 70 70 70 70 70 70 70 70 70 Sat 60 60 60 60 60 60 70 70 70 70 70 70 70 70 70 Sun 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 CDD 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 HDD 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 Cooling Temp WD 86 86 86 86 8 6 86 75 75 75 75 75 75 75 75 75 Sat 86 86 86 86 86 86 75 75 75 75 75 75 75 75 75 Sun 86 86 86 86 86 86 86 86 86 86 86 86 86 86 86 CDD 75 75 75 75 75 75 75 75 75 75 75 75 75 75 75 HDD 86 86 86 86 86 86 86 86 86 86 86 86 86 86 86

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71 Table B 1. Continued Schedule Type Day of Week 16 17 18 19 20 21 22 23 24 DHW Fraction WD 0.33 0.44 0.26 0.21 0.15 0.17 0.08 0.05 0.05 Sat 0.12 0.14 0.07 0.07 0.07 0.07 0.09 0.05 0.05 Sun 0.04 0.04 0.04 0.04 0.04 0.04 0.07 0.04 0.04 CDD 1 1 1 1 1 1 1 1 1 HDD 0 0 0 0 0 0 0 0 0 HVAC On/Off WD 1 1 1 1 1 1 1 0 0 Sat 1 1 1 0 0 0 0 0 0 Sun 0 0 0 0 0 0 0 0 0 Heating Temp WD 70 70 70 70 70 70 70 60 60 Sat 70 70 70 60 60 60 60 60 60 Sun 60 60 60 60 60 60 60 60 60 CDD 60 60 60 60 60 60 60 60 60 HDD 70 70 70 70 70 70 70 70 70 Cooling Temp WD 75 75 86 86 86 86 86 86 86 Sat 75 75 75 86 86 86 86 86 86 Sun 86 86 86 86 86 86 86 86 86 CDD 75 75 75 75 75 75 75 75 75 HDD 86 86 86 86 86 86 86 86 86

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72 Table B 2. Baseline model lighting power c alculations Room Name Room Number Room Use HVAC Zone Lighting Density (W/ft 2 ) Lighting Total Watts Waiting/Reception A 01 Reception Lobby Area 1.3 457.1 Office A 02 Office (Open Plan) Lobby Area 1.1 310.1 Workroom A 03 Office (Private) Lobby Area 1.1 113.0 File Room A -04 Office (Private) Conference Area 1.1 280.7 Office A 05 Office (Private) Conference Area 1.1 124.7 Conference A 06 Conference Conference Area 1.3 459.9 Conference A 07 Conference Conference Area 1.3 2 15.3 Kitchenette A -08 Breakroom Conference Area 1.3 109.6 HVAC A 09 Mech/Elec Room Conference Area 1.5 53.0 Corridor A -10 Office (Open Plan) Conference Area 0.5 59.2 Supplies A 11 Reception Lobby Area 0.3 3.9 Men's Room A 12 Restroom Lobby Area 0.9 38 .7 Women's Room A 13 Restroom Lobby Area 0.9 37.6 Men's Room A 14 Restroom Lobby Area 0.9 36.9 Women's Room A 15 Restroom Lobby Area 0.9 57.3 Team Area A -16 Office (Open Plan) Team Area 1 1.1 829.0 Team Area A 17 Office (Open Plan) Team Area 2 1.1 829 .0 Team Area A 18 Office (Open Plan) Team Area 3 1.1 829.0 Partner Office A 19 Office (Private) Private Office Area 1.1 207.2 Office A 20 Office (Private) Private Office Area 1.1 174.2 Partner Office A 21 Office (Private) Private Office Area 1.1 203.2 Copy/Plotter A -22 Copy Room Private Office Area 1.3 223.7 Telecom A 23 Mech/Elec Room Private Office Area 1.5 46.8 Partner Office A 24 Office (Private) Private Office Area 1.1 203.2 Partner Office A 25 Office (Private) Private Office Area 1.1 207.2 Co rridor A -26 Office (Open Plan) Private Office Area 0.5 226.5 Corridor A 27 Office (Open Plan) Conference Area 0.5 81.7 HVAC A -28 Mech/Elec Room Private Office Area 1.5 21.3 Waiting/Reception B 01 Reception Suite B 1.3 236.7 Conference B 02 Conference S uite B 1.3 230.6 Office B 03 Office (Private) Suite B 1.1 144.0 Office B 04 Office (Private) Suite B 1.1 144.0 Office B 05 Office (Private) Suite B 1.1 196.6 Office B-06 Office (Private) Suite B 1.1 181.0 Copy Room B 07 Copy Room Suite B 1.3 132.2 To ilet B 08 Restroom Suite B 0.9 91.5 HVAC B 09 Mech/Elec Room Suite B 1.5 15.4 Corridor B 10 Office (Open Plan) Suite B 0.9 70.6

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73 Table B 3. Baseline model plug load c alculations Room Name Room Number HVAC Zone Group Office Equipment Qty. Total W Waitin g/Reception A 01 Lobby Area Computers desktop 1 65 Lobby Area Monitors LCD 1 36 Lobby Area Multifunction 1 135 Lobby Area Fax machine 1 20 Office A 02 Lobby Area Computers desktop 2 130 Lobby Area Monitors LCD 2 72 Workroom A 03 Lobby Area None 0 File Room A 04 Conference Area None 0 Office A 05 Conference Area Computers desktop 1 65 Conference Area Monitors LCD 1 36 Conference A 06 Conference Area Computers desktop 1 65 Conference Area None 0 Conf erence Area Projector 1 185 Conference A 07 Conference Area None 0 Kitchenette A 08 Conference Area Water cooler 1 350 Conference Area Refrigerator 1 76 Conference Area Vending machine snack 1 275 Conference Area Microwave 1 400 C onference Area Coffee maker 0 0 HVAC A 09 Conference Area None 0 Corridor A 10 Conference Area None 0 Supplies A 11 Lobby Area None 0 Men's Room A 12 Lobby Area None 0 Women's Room A 13 Lobby Area None 0 Men's Room A 14 Lobby Area None 0 Women's Room A 15 Lobby Area None 0 Team Area A 16 Team Area 1 Computers desktop 7 455 Team Area 1 Monitors LCD 7 252 Team Area A 17 Team Area 2 Computers desktop 7 455 Team Area 2 Monitors LCD 7 252 Team Area A 18 Team Area 3 Compu ters desktop 7 455 Team Area 3 Monitors LCD 7 252 Partner Office A 19 Private Office Area Computers desktop 1 65 Private Office Area Monitors LCD 1 36 Office A 20 Private Office Area Computers desktop 1 65 Private Office Area Mon itors LCD 1 36 Partner Office A 21 Private Office Area Computers desktop 1 65 Private Office Area Monitors LCD 1 36 Copy/Plotter A 22 Private Office Area Copy machine (large) 1 1,100 Telecom A 23 Private Office Area Computers servers 1 65 Private Office Area Monitors LCD 1 36 Partner Office A 24 Private Office Area Computers desktop 1 65 Private Office Area Monitors LCD 1 36

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74 Table B 3. Continued Room Name Room Number HVAC Zone Group Office Equipment Qty. Total W Partner Office A 25 Private Office Area Computers desktop 1 65 Private Office Area Monitors LCD 1 36 Corridor A 26 Private Office Area None 0 Corridor A 27 Conference Area None 0 HVAC A 28 Private Office Area None 0 Waiting/Reception B 01 Suite B Computers desktop 1 65 Suite B Monitors LCD 1 36 Suite B Multifunction 1 135 Suite B Fax machine 1 20 Conference B 02 Suite B None 0 Office B 03 Suite B Computers desktop 1 65 Suite B Monitors LCD 1 36 Office B 04 Suite B Computers desktop 1 65 Suite B Monitors LCD 1 36 Office B 05 Suite B Computers desktop 1 65 Suite B Monitors LCD 1 36 Office B 06 Suite B Computers desktop 1 65 Suite B Monitors LCD 1 36 Copy Room B 07 Suite B Copy machine (l arge) 1 1,100 Toilet B 08 Suite B None 0 HVAC B 09 Suite B None 0 Corridor B 10 Suite B None 0 TableB 4. Baseline office equipment power u sage Office Equipment Inventory Peak Power (W) Computers servers 65 Computers desktop 65 Computers laptop 40 Monitors LCD 36 Laser printer desktop 110 Copy machine (large) 1100 Multifunction 135 Fax machine 20 Water cooler 350 Refrigerator 76 Vending machine snack 275 Coffee maker 1500 Microwave 400 Projector 185

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75 Table B 4. EIR cal culations for heating and c ooling Data from eQuest Supply Air Volume and Fan Efficiency System Gross Cooling Capacity Heating Capacity Supply Air Volume Baseline Fan Motor Brake Horsepower Baseline Supply Fan Power Supply Fan kW/CFM Btu/hr Btu/hr C FM hp kW kW/CFM Office 1 37,921 41,391 824 0.71 0.66 0.000806 Office 2 35,114 38,486 745 0.64 0.60 0.000811 Office 3 34,820 38,165 743 0.64 0.60 0.000811 Private Offices 68,083 95,351 1,469 1.27 1.15 0.000780 Conference Area 74,424 102,923 1,539 1.33 1.20 0.000778 Lobby 48,802 53,481 992 0.86 0.79 0.000797 Suite B 73,568 53,987 1,634 1.41 1.27 0.000776 Table B 4. Continued Supply Fan Power and Cooling EIR System Net Cooling Capacity Gross Cooling Capacity Total EER Total Input Power Cooling Power Cooling COP Cooling EIR Total EIR Btu/hr Btu/hr Btu/hr/W kW kW Office 1 35,655 37,921 10.70 3.3 2.7 4.16 0.240 0.319 Office 2 33,052 35,114 10.70 3.1 2.5 4.14 0.242 0.319 Office 3 32,764 34,820 10.70 3.1 2.5 4.15 0.241 0.319 Priva te Offices 64,173 68,083 9.90 6.5 5.3 3.74 0.268 0.345 Conference Area 70,337 74,424 9.90 7.1 5.9 3.69 0.271 0.345 Lobby 46,104 48,802 10.70 4.3 3.5 4.06 0.246 0.319 Suite B 69,242 73,568 9.90 7.0 5.7 3.76 0.266 0.345

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76 Table B 4. Continued Suppl y Fan Power and Heating EIR System Net Heating Capacity Heating Capacity Total EER Total Input Power Heating Power Heating COP Heating EIR Total EIR Btu/hr Btu/hr Btu/hr/W kW kW Office 1 39,125 41,391 11.00 3.6 2.9 4.19 0.239 0.310 Of fice 2 36,424 38,486 11.00 3.3 2.7 4.17 0.240 0.310 Office 3 36,109 38,165 11.00 3.3 2.7 4.17 0.240 0.310 Private Offices 91,441 95,351 7.50 12.2 11.0 2.53 0.395 0.455 Conference Area 98,836 102,923 7.50 13.2 12.0 2.52 0.397 0.455 Lobby 50,783 53,4 81 11.00 4.6 3.8 4.10 0.244 0.310 Suite B 49,661 53,987 11.00 4.5 3.2 4.87 0.205 0.310

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77 Table B 5. Minimum o utdoor air c alculations Room Name Room Area Az (ft2) Room Number Space Type Room Pop. Pz (per) People Outdoor Air Rate Rp (cfm/per) Area Outd oor Air Rate Ra (cfm/ft2) Pz*Rp (cfm) Az*Ra (cfm) Zone Air Distribution Effectiveness Ez Outdoor airflow to the space corrected for zone air distribution effectiveness Voz (Pz*Rp + Az*Ra)/Ez, cfm Waiting/ Reception 352 A 01 Reception areas 3 5.0 0.06 15 .0 21.10 1 36.10 Office 282 A 02 Office space 2 5.0 0.06 10.0 16.91 1 26.91 Workroom 103 A 03 Storage rooms 0 0.0 0.12 0.0 12.33 1 12.33 File Room 255 A 04 Storage rooms 0 0.0 0.12 0.0 30.62 1 30.62 Office 113 A 05 Office space 1 5.0 0.06 5.0 6.80 1 11 .80 Conference 354 A -06 Conference / meeting 12 5.0 0.06 60.0 21.23 1 81.23 Conference 166 A 07 Conference / meeting 6 5.0 0.06 30.0 9.94 1 39.94 Kitchenette 84 A 08 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 HVAC 35 A 09 Does not apply 0 0.0 0.00 0.0 0 .00 1 0.00 Corridor 118 A 10 Corridors 0 0.0 0.06 0.0 7.10 1 7.10 Supplies 13 A 11 Storage rooms 0 0.0 0.12 0.0 1.55 1 1.55 Men's Room 43 A 12 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 Women's Room 42 A 13 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 Men 's Room 41 A 14 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00

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78 Table B 5. Continued Room Name Room Area Az (ft2) Room Number Space Type Room Pop. Pz (per) People Outdoor Air Rate Rp (cfm/per) Area Outdoor Air Rate Ra (cfm/ft2) Pz*Rp (cfm) Az*Ra (cfm) Zone A ir Distribution Effectiveness Ez Outdoor airflow to the space corrected for zone air distribution effectiveness Voz (Pz*Rp + Az*Ra)/Ez, cfm Women's Room 64 A 15 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 Team Area 754 A 16 Office space 7 5.0 0.06 35.0 45 .22 1 80.22 Team Area 754 A 17 Office space 7 5.0 0.06 35.0 45.22 1 80.22 Team Area 754 A -18 Office space 7 5.0 0.06 35.0 45.22 1 80.22 Partner Office 188 A 19 Office space 1 5.0 0.06 5.0 11.30 1 16.30 Office 158 A 20 Office space 1 5.0 0.06 5.0 9.50 1 14.50 Partner Office 185 A 21 Office space 1 5.0 0.06 5.0 11.09 1 16.09 Copy/ Plotter 172 A 22 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 Telecom 31 A -23 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 Partner Office 185 A 24 Office space 1 5.0 0.06 5.0 11.0 9 1 16.09 Partner Office 188 A 25 Office space 1 5.0 0.06 5.0 11.30 1 16.30 Corridor 453 A 26 Corridors 0 0.0 0.06 0.0 27.18 1 27.18 Corridor 163 A -27 Corridors 0 0.0 0.06 0.0 9.80 1 9.80 HVAC 14 A 28 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00

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79 Table B 5. Continued Room Name Room Area Az (ft2) Room Number Space Type Room Pop. Pz (per) People Outdoor Air Rate Rp (cfm/per) Area Outdoor Air Rate Ra (cfm/ft2) Pz*Rp (cfm) Az*Ra (cfm) Zone Air Distribution Effectiveness Ez Outdoor airflow to the space corrected for zone air distribution effectiveness Voz (Pz*Rp + Az*Ra)/Ez, cfm Waiting/ Reception 182 B 01 Reception areas 5 5.0 0.06 27.3 10.92 1 38.23 Conference 177 B 02 Conference / meeting 9 5.0 0.06 44.3 10.64 1 54.99 Office 131 B 03 Office space 1 5. 0 0.06 3.3 7.85 1 11.12 Office 131 B-04 Office space 1 5.0 0.06 3.3 7.85 1 11.12 Office 179 B 05 Office space 1 5.0 0.06 4.5 10.72 1 15.19 Office 165 B 06 Office space 1 5.0 0.06 4.1 9.87 1 13.99 Copy Room 102 B 07 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 Toilet 102 B 08 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 HVAC 10 B 09 Does not apply 0 0.0 0.00 0.0 0.00 1 0.00 Corridor 78 B 10 Corridors 0 0.0 0.06 0.0 4.70 1 4.70

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80 APPENDIX C PROPOSED MODEL INPUT S Table C 1. Proposed model lighting c alculati ons Room Name Room Number Lighting Fixture W/Fixture # of Fixtures Total Watts Total Watts w/ Occupancy Sensor Waiting/ Reception A 01 (2) 48 in. T8 lamp, Electronic 64 5 320 288 Office A 02 (2) 48 in. T8 lamp, Electronic 64 4 256 230 Workroom A 03 (2) 48 in. T8 lamp, Electronic 64 2 128 115 File Room A -04 (2) 48 in. T8 lamp, Electronic 64 5 320 288 Office A 05 (2) 48 in. T8 lamp, Electronic 64 2 128 115 Conference A 06 (2) 48 in. T8 lamp, Electronic 64 6 384 346 Conference A 07 (2) 48 in. T8 lamp, E lectronic 64 2 128 115 Kitchenette A 08 (2) 48 in. T8 lamp, Electronic 64 2 128 115 HVAC A 09 None 0 0 0 0 Corridor A 10 (2) 48 in. T8 lamp, Electronic 64 1 64 58 Supplies A 11 (1) 48 in. T8 lamp, Electronic 32 0 0 0 Men's Room A 12 (1) 48 in. T8 lamp Electronic 32 1 32 29 Women's Room A 13 (1) 48 in. T8 lamp, Electronic 32 1 32 29 Men's Room A 14 (1) 48 in. T8 lamp, Electronic 32 1 32 29 Women's Room A 15 (1) 48 in. T8 lamp, Electronic 32 1 32 29 Team Area A 16 (2) 48 in. T8 lamp, Electronic 64 9 576 518 Team Area A 17 (2) 48 in. T8 lamp, Electronic 64 9 576 518 Team Area A 18 (2) 48 in. T8 lamp, Electronic 64 9 576 518 Partner Office A 19 (2) 48 in. T8 lamp, Electronic 64 4 256 230 Office A 20 (2) 48 in. T8 lamp, Electronic 64 4 256 230

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81 Ta ble C 1. Continued Room Name Room Number Lighting Fixture W/Fixture # of Fixtures Total Watts Total Watts w/ Occupancy Sensor Partner Office A 21 (2) 48 in. T8 lamp, Electronic 64 4 256 230 Copy/Plotter A 22 (2) 48 in. T8 lamp, Electronic 64 2 128 115 Telecom A -23 (1) 48 in. T8 lamp, Electronic 32 1 32 29 Partner Office A 24 (2) 48 in. T8 lamp, Electronic 64 4 256 230 Partner Office A 25 (2) 48 in. T8 lamp, Electronic 64 4 256 230 Corridor A 26 (2) 48 in. T8 lamp, Electronic 64 5 320 288 Corridor A 27 (2) 48 in. T8 lamp, Electronic 64 3 192 173 HVAC A 28 None 0 0 0 0 Waiting/ Reception B 01 (2) 48 in. T8 lamp, Electronic 64 3 192 173 Conference B 02 (2) 48 in. T8 lamp, Electronic 64 4 256 230 Office B 03 (2) 48 in. T8 lamp, Electronic 64 2 128 11 5 Office B-04 (2) 48 in. T8 lamp, Electronic 64 2 128 115 Office B 05 (2) 48 in. T8 lamp, Electronic 64 3 192 173 Office B 06 (2) 48 in. T8 lamp, Electronic 64 2 128 115 Copy Room B 07 (2) 48 in. T8 lamp, Electronic 64 2 128 115 Toilet B 08 (2) 48 in. T8 lamp, Electronic 64 1 64 58 HVAC B 09 None 0 0 0 0 Corridor B 10 (2) 48 in. T8 lamp, Electronic 64 1 64 58

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82 Table C 2. Proposed model plug load c alculations Room Name Room Number HVAC Zone Group Office Equipment Qty. Energy Star Total W Waiting/ Reception A -01 Lobby Area Computers laptop 1 27 Lobby Area Monitors LCD 1 28 Lobby Area Multifunction 1 68 Lobby Area Fax machine 1 10 Office A 02 Lobby Area Computers laptop 2 54 Lobby Area Monitors LCD 2 56 Office A 05 Confe rence Area Computers laptop 1 27 Conference Area Monitors LCD 1 28 Conference A 06 Conference Area Computers laptop 1 27 Conference Area Projector 1 185 Kitchenette A 08 Conference Area Water cooler 1 193 Conference Area Refrigerator 1 61 Conference Area Vending machine snack 1 129 Conference Area Microwave 1 400 Team Area A 16 Team Area 1 Computers laptop 7 188 Team Area 1 Monitors LCD 7 197 Team Area A 17 Team Area 2 Computers laptop 7 188 Team Area 2 M onitors LCD 7 197 Team Area A 18 Team Area 3 Computers laptop 7 188 Team Area 3 Monitors LCD 7 197 Partner Office A 19 Private Office Area Computers laptop 1 27 Private Office Area Monitors LCD 1 28 Office A 20 Private Office Area Co mputers laptop 1 27 Private Office Area Monitors LCD 1 28 Partner Office A 21 Private Office Area Computers laptop 1 27 Private Office Area Monitors LCD 1 28 Copy/ Plotter A 22 Private Office Area Copy machine (large) 1 1,023 Telecom A 23 Private Office Area Computers servers 1 44 Private Office Area Monitors LCD 1 28 Partner Office A 24 Private Office Area Computers laptop 1 27 Private Office Area Monitors LCD 1 28 Partner Office A 25 Private Office Area Computers laptop 1 27 Private Office Area Monitors LCD 1 28 Waiting/ Reception B-01 Suite B Computers laptop 1 27 Suite B Monitors LCD 1 28 Suite B Multifunction 1 68 Suite B Fax machine 1 10 Office B 03 Suite B Computers laptop 1 27 Suite B Monitors LCD 1 28 Office B 04 Suite B Computers laptop 1 27 Suite B Monitors LCD 1 28

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83 Table C 2. Continued Room Name Room Number HVAC Zone Group Office Equipment Qty. Energy Star Total W Office B 05 Suite B Computers laptop 1 27 Suite B Monitors LCD 1 28 Office B 06 Suite B Computers laptop 1 27 Suite B Monitors LCD 1 28 Copy Room B 07 Suite B Copy machine (large) 1 1,023

PAGE 84

84 APPENDIX D BASELINE ENERGY SIMU LATION OUTPUT

PAGE 85

85 APPENDIX E PROPOSED ENERGY SIMULAT ION OUTPUT

PAGE 86

86 APPENDIX F LIFE CYCLE COST CALC ULATIONS

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87 LIST OF REFERENCES A NSI/ASHRAE. 2004. ANSI/ASHRAE Standard 62.12004, Ventilation for Acceptable Indoor Air Quality, American Society of Heating, Refrigerating and Air Conditioning Engineers, Atlan ta, Georgia. ANSI/ASHRAE/IESNA. 2004a. ANSI/ASHRAE/IESNA Standard 90.12004, Energy Standard for Buildings Except Low Rise Residential Buildings. American Society of Heating, Refrigerating and AirConditioning Engineers, Atlanta, Georgia. ANSI/ASHRAE/IES NA. 2004b. Users Manual for ANSI/ASHRAE/IESNA Standard 90.12004, Energy Standard for Buildings Except Low Rise Residential Buildings. American Society of Heating, Refrigerating and AirConditioning Engineers, Atlanta, Georgia. ASHRAE. 2004. Advanced Ene rgy Design Guide for Small Office Building. American Society of Heating, Refrigerating and Air Conditioning Engineers, Atlanta, Georgia. ASHRAE. 2006. ASHRAE GreenGuide: The Design, Construction, and Operation of Sustainable Buildings American Society of Heating, Refrigerating and Air Conditioning Engineers, Atlanta, Georgia. ASHRAE. 2007. HVAC Applications Handbook American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., Atlanta, Georgia. ASHRAE. 2009. Handbook of Fundamentals American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., Atlanta, Georgia. Bose, et al. 1985. Design/Data Manual for ClosedLoop GroundCoupled Heat Pump Systems American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., Atlanta, Georgia. CBECS. 2003. Commercial Buildings Energy Consumption Survey 2003 Energy Information Administration of U.S. Department of Energy, Washington, D.C. Last accessed in May, 2010 at http://www.eia.doe.gov/emeu/cbecs/contents.htm l DOE. 2000. Technical Support Document: Energy Efficiency Standards For Consumer Products: Residential Water Heaters U.S. Department of Energy, Washington, D.C. DOE. 2008. Zero Energy Buildings Database U.S. Department of Energy. Washington, D.C. Last accessed May 2010 at http://zeb.buildinggreen.com/ EIA. 2009. Annual Energy Outlook 2009, Energy Information Administration of U.S. Department of Energy, Washington, D.C. Emmerich, S.J., et al. 2007. Simulation of the Impact of Commercial Building Envel ope Airtightness on Building Energy Utilization. ASHRAE Transactions Volume 113, Part 2.

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88 Energy Independence and Security Act of 2007 42 U.S.C. (2007) EPA. 2009. ENERGY STAR Products U.S. Environmental Protection Agency. Washingon, D.C. La st accessed in June 2010 at http://www.energystar.gov/index.cfm?fuseaction=find_a_product Fisk, W.J. 2000. Health and Productivity Gains from Better Indoor Environments and Their Implications for the U.S. Department of Energy Lawrence Berkeley National Laboratory. Berkeley, CA. Gowri, K., D.W. Winiarski, and R.E. Jarnagin. 2009. Infiltration Modeling Guidelines for Commercial Building Energy Analysis PNNL 18898, Pacific Northwest National Laboratory, Richland, WA. Griffith, B, N. Long, P. Torcellini R. Judkoff, D. Crawley, D. and J. Ryan. 2007. Assessment of th e Technical Potential for Achieving Net ZeroEnergy Buildings in the Commercial Sector TP550 41957, National Renewable Energy Laboratory, Golden, Colorado. Griffith, B, N. Long, P. Torcelli ni, R. Judkoff, D. Crawley, D. and J. Ryan. 2008. Methodology for Modeling Building Energy Performance across the Commercial Sector. TP55041956, National Renewable Energy Laboratory, Golden, Colorado. He erwage n, J. 2001. Do Green Buildings Enhance the W ell Being of Workers? Last accessed in May 2010 at http://www.edcmag.com/CDA/Archives/fb077b7338697010VgnVCM100000f932a8c0 Hughes, P. 2008. Geothermal (GroundSource) Heat Pumps: Market Status, Barriers to Adoption, and Actions to Overcome Barriers TM/ 2008/232. Oak Ridge National Laboratory, Oak Ridge, Tennessee. Jarnagin, R.E., B. Liu, D.W. Winiarski, M.F. McBride, L. Suharli, and D.Walden. 2006. Technica l Support Document: Development of the Advanced Energy Design Guide for Small Office Buildings. PNNL 16250, Pacific Northwest National Laboratory. Richland, Washington. Kats, G. 2003. The Costs and Financial Benefits of Green Buildings Last accessed in May 2010 at http://www.usgbc.org/ShowFile.aspx?DocumentID=1992 Kendall, M. M. Scholand. 2001. Energ y Savings Potential of Solid State Lighting in General Lighting Applications U.S. Department of Energy, Washington, D.C. Langdon, D. 2007. Cost of Green Revisited: Reexamining the Feasibility and Cost Impact of Sustainable Design in the Light of Increase d Market Adoption Last accessed in May 2010 at http://www.davislangdon.com/upload/images/publications/USA/The%20Cost%20of%20 Green%20Revisited.pdf

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89 RS Means. 2009. Building Cost Data. Kingston, Massachusetts. Torcellini, P., S. Pless, M. Deru, and D. Craw ley. 2006. Zero Energy Buildings: A Critical Look at the Definition CP 550 39833, National Renewable Energy Laboratory, Golden, Colorado. Torcellini, P., S. Pless, M. Deru, B. Griffith, N. Long, and R. Judkoff. 2006a Lessons Learned from Case Studies of Six HighPerformance Buildings TP550 37542. National Renewable Energy Laboratory, Golden, Colorado. Torcellini, P., M. Deru, B. Griffith, K. Benne, M. Halverson, D. Winiarski, and D.B. Crawley. 2008. DOE Commercial Building Benchmark Models CP 550 43291. National Renewable Energy Laboratory, Golden, Colorado. Wassmer, M., and M. J. Brandemuehl. 2006. Effect of Data Availability on Modeling of Residential Air Conditioners and Heat Pumps for Energy Calculations ASHRAE Transactions 111(1), pp. 214225.

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90 BIOGRAPHICAL SKETCH Thomas Vu was born and raised in Melbourne, Florida He graduated from Melbourne Central Catholic High School in 2003 and began his college career at the University of Florida. In 2008, Thomas received his Bachelor of Science degree in mechanical e ngineering and decided to continue his education at UF and pursue Master of Science degrees in mechanical engineering and management. Thomas has worked as an engineering intern with Reynolds, Smith, and Hills, Inc. and Affiliated Engineers, Inc, working on Heating, Ventilating, and Air Conditioning design projects, building energy audits, and building energy modeling. He plans to obtain his P rofessional E ngineering L i cense as well as Leadership in Energy and Environmental Design A ccredited P rofessional certification After graduate school, Thomas wants to work in the HVAC industry to design sustainable high performance buildings.