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Decision Matrices for HVAC Systems for Florida Public Schools

Permanent Link: http://ufdc.ufl.edu/UFE0041666/00001

Material Information

Title: Decision Matrices for HVAC Systems for Florida Public Schools
Physical Description: 1 online resource (84 p.)
Language: english
Creator: Mclaughlin, Kelly
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: costs, cycle, decision, florida, hvac, life, matrix, schools
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The purpose of this research was to develop a decision matrix that would aid the Florida Department of Education in the selection of the most appropriate and cost-effective HVAC system for Florida public schools. A decision matrix was developed that included the system selection criteria most pertinent to the needs of school facilities. This matrix contained both life cycle cost and design criteria. A general life cycle cost analysis was performed in order to determine the most cost effective HVAC system. Methods were developed to rate the design criteria. The results of these calculations were placed in the proposed decision matrix to compare the systems. From the research conducted it was found that a general life cycle cost analysis of HVAC systems was not possible to perform. The HVAC industry does not track system costs on a general basis. As such, the costs used in the life cycle cost calculations were for the HVAC units only. The proposed decision matrix effectively presented the HVAC unit performance in both the cost and design criteria categories. The rating scales developed allowed users to identify the HVAC system that would best fit their needs. The proposed decision matrix could also be adapted to meet the specific needs of individual school districts throughout the State of Florida.
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 Kelly Mclaughlin.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2010.
Local: Adviser: Oppenheim, Paul.
Local: Co-adviser: Kibert, Charles J.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041666:00001

Permanent Link: http://ufdc.ufl.edu/UFE0041666/00001

Material Information

Title: Decision Matrices for HVAC Systems for Florida Public Schools
Physical Description: 1 online resource (84 p.)
Language: english
Creator: Mclaughlin, Kelly
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: costs, cycle, decision, florida, hvac, life, matrix, schools
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The purpose of this research was to develop a decision matrix that would aid the Florida Department of Education in the selection of the most appropriate and cost-effective HVAC system for Florida public schools. A decision matrix was developed that included the system selection criteria most pertinent to the needs of school facilities. This matrix contained both life cycle cost and design criteria. A general life cycle cost analysis was performed in order to determine the most cost effective HVAC system. Methods were developed to rate the design criteria. The results of these calculations were placed in the proposed decision matrix to compare the systems. From the research conducted it was found that a general life cycle cost analysis of HVAC systems was not possible to perform. The HVAC industry does not track system costs on a general basis. As such, the costs used in the life cycle cost calculations were for the HVAC units only. The proposed decision matrix effectively presented the HVAC unit performance in both the cost and design criteria categories. The rating scales developed allowed users to identify the HVAC system that would best fit their needs. The proposed decision matrix could also be adapted to meet the specific needs of individual school districts throughout the State of Florida.
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 Kelly Mclaughlin.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2010.
Local: Adviser: Oppenheim, Paul.
Local: Co-adviser: Kibert, Charles J.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041666:00001


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1 DECISION MATRICES FOR HVAC SYSTEMS FOR FLORIDA PUBLIC SCHOOLS By KELLY JESSICA MCLAUGHLIN A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE O F MASTER OF SCIENCE IN BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2010

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2 2010 Kelly Jessica McLaughlin

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3 To my family for their unconditional love and support

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4 ACKNOWLEDGMENTS I would like to thank my family for their suppor t and encouragement. I would also like to thank Dr. Paul Oppenheim for his guidance throughout this study.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................. 4 LIST O F TABLES ............................................................................................................ 7 LIST OF ABBREVIATIONS ........................................................................................... 10 ABSTRACT ................................................................................................................... 11 CHAPTER 1 INTRODUCTION .................................................................................................... 13 Background ............................................................................................................. 13 Objective of the Study ............................................................................................. 13 Limitations ............................................................................................................... 14 2 LITERATURE REVIEW .......................................................................................... 15 HVAC System Selection Process ........................................................................... 15 Selecti on Matrix ...................................................................................................... 16 Life Cycle Cost Analysis ......................................................................................... 19 3 METHODOLOGY ................................................................................................... 25 Introd uction ............................................................................................................. 25 Selection of Decision Matrix Criteria ....................................................................... 25 Life Cycle Cost Criteria ..................................................................................... 26 Design Selection Criteria .................................................................................. 27 Organization of HVAC Systems .............................................................................. 28 Development of Decision Matrix ............................................................................. 29 Life Cycle Cost Analysis ......................................................................................... 31 First Costs ........................................................................................................ 33 Energy Costs .................................................................................................... 37 Maintenance Costs ........................................................................................... 39 Replacement Costs .......................................................................................... 40 Replacement of HVAC units ...................................................................... 40 Replacement of miscellaneous equipment ................................................ 40 Life Cycle Cost ................................................................................................. 41 Design Criteria Ana lysis .......................................................................................... 41 Required Space ................................................................................................ 41 Complexity ........................................................................................................ 42 Life of the Unit .................................................................................................. 42 Noise ................................................................................................................ 45

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6 Temperature Control ........................................................................................ 46 Humidity Control ............................................................................................... 47 4 DATA ...................................................................................................................... 48 Cost Criteria ............................................................................................................ 48 First Costs ........................................................................................................ 48 Energy Costs .................................................................................................... 50 Maintenance Costs ........................................................................................... 53 Replacement Costs .......................................................................................... 54 Life Cycle Cost ................................................................................................. 56 Design Criteria ........................................................................................................ 59 Required Space ................................................................................................ 59 Complexity ........................................................................................................ 59 Life of the Unit .................................................................................................. 64 Noise ................................................................................................................ 64 Tempera ture Control ........................................................................................ 65 5 RESULTS ............................................................................................................... 69 DX and Chiller Systems .......................................................................................... 69 Air Distr ibution Systems .......................................................................................... 69 6 CONCLUSIONS ..................................................................................................... 71 7 RECOMMENDATIONS ........................................................................................... 72 APPENDIX A INSTALLATION COSTS OF FLORIDA SCHOOLS ................................................ 73 B PRESENT VALUE CALCULATIONS ...................................................................... 75 Energy Costs .......................................................................................................... 75 Maintenance Costs ................................................................................................. 77 Replacement Costs ................................................................................................ 79 LIST OF REFERENCES ............................................................................................... 82 BIOGRAPHICAL SKETCH ............................................................................................ 84

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7 LIST OF TABLES Table page 2 1 Decision Matrix for the Comparison of HVAC Systems ...................................... 17 2 2 Decision matrix using both per formance and numerical rating ........................... 18 2 3 Deci sion Matrix with Weight Factors ................................................................... 19 2 4 System selection matrix utilizing both qualitative and quantitative rating methods .............................................................................................................. 21 3 1 HVAC systems included in study ........................................................................ 29 3 3 Life cycle cost parameters .................................................................................. 31 3 2 Example of the proposed decision matrix displaying the color coding and ranking of systems .............................................................................................. 32 4 1 First costs of DX and Chiller units based off of actual supplier quotes ............... 48 4 2 First Cost of Air Distribution devices based off of actual supplier quotes ........... 49 4 3 General quotes of the installation costs of DX systems ...................................... 50 4 4 Summary and ranking of the first cost per ton for DX and Chiller systems ......... 51 4 5 Summary and ranking of the first cost per unit for Air Distribution systems ........ 51 4 6 Calculation of energ y costs of DX units .............................................................. 52 4 7 Calculation of energy costs of Chiller systems ................................................... 52 4 8 Summary and ranking of energy costs for the DX and Chiller units .................... 54 4 9 Present value of the cost of maintenance over a 50 year building life ................ 54 4 10 Summary and ranking of u nit maintenance costs ............................................... 54 4 11 Calculation of periodic unit replacement costs ................................................... 57 4 12 Calculation of miscellaneous equipment cost s ................................................... 58 4 13 Summary and ranking of DX and Chiller replacement costs .............................. 58 4 14 Summary and ranking of Air Distribution replacement costs .............................. 58 4 19 Explanation of rating system for the required space criterion ............................. 59

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8 4 15 Summary and ranking of the life cycle costs for the DX and Chiller units ........... 60 4 16 Summary and ranking of the life cycle costs for the Air Distribution systems ..... 60 4 17 Space ch aracteristics for typical designs of DX and Chiller systems. ................. 61 4 18 Calculation of the amount of required space needed for DX and Chiller systems. ............................................................................................................. 62 4 20 Space characteristics of typical Air Distribution systems .................................... 63 4 21 Calculation of required space for Air Distribution systems. ................................. 63 4 22 Ranking of the complexity of the DX and Chiller systems .................................. 63 4 23 Ranking of the complexity of the Air Distribution systems .................................. 64 4 25 Potential sources of noise in classroom ............................................................. 65 4 24 Summary of sources examined in the determination of unit service life ............. 66 4 26 Rating of noise characteristics for HVAC systems .............................................. 67 4 27 Ranking of the Air Distribution systems ability to control temperature of the space .................................................................................................................. 68 5 1 Completed decision matrix for DX and Chiller systems ...................................... 70 5 2 Completed decision matrix for the Air Distribution systems ................................ 70 A 1 HVAC system component costs for two elementary schools in Pasco County Florida ................................................................................................................ 73 A 2 Total c osts for the installation of an air cooled chi ller system in Pasco County elementary schools ............................................................................................. 74 B 1 Summary of costs and rates used in the calculation of the total present value of unit energy costs ............................................................................................ 75 B 2 Calculation of total present value of unit energy cost ......................................... 75 B 3 Summary of costs and rates used in the calculation of the total present value of unit maintenance costs ................................................................................... 77 B 4 Calculation of the total present value of unit maintenance cost .......................... 77

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9 B 5 Summary of costs and rates used in the calc ulation of the total present value of miscellaneous unit replacement costs ............................................................ 79 B 6 Calculation of the total present value of miscellaneous unit replacement costs 79

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10 LIST OF ABBREVIATION S AHU Air Handling Unit ANSI American National Standards Institute ASHRAE American Society of Heating, Refrigerati n g and Air Conditioning Engineers DX Direct Expansion Systems CFM Cubic Feet per Minute EER Energy Efficiency Ratio EFLOH Equivalent Full Load operating hours HVAC Heating, ventilating and air conditioning LCC Life Cycle Cost LCCA Life Cycle Cost Analysis VAV Variable Air Volume

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11 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science in Building Construction DECISION MATRICES FOR HVAC SYSTEMS FOR FLORIDA PUBLIC SCHOOLS By Kelly Jessica McLaughlin May 2010 Chair: Paul Oppenheim Cochair: Charle s Kibert Major: Building Construction The purpose of t his research was to dev elop a decision matrix that would aid the Florida Department of Education in the selection of the most appropriate and cost effective HVAC system for Florida public schools A d ecision matrix was developed that included the system selection criteria most pertinent to the needs of school facilities. This matrix contained both life cycle cost and design criteria. A general life cycle cost analysis was performed in order to determin e the most cost effective HVAC system. Methods were developed to rate the design criteria. The results of these calculations were placed in the proposed decision matrix to compare the systems. From the research conducted it was found that a general life cy cle cost analysis of HVAC systems was not possible to perform. T he HVAC industry does not track system costs on a general basis. As such, the costs used in the life cycle cost calculations were for the HVAC units only. The proposed decision matrix effecti vely presented the HVAC unit performance in both the cost and design criteria categories The rating scales developed allowed users to identify the HVAC system that would best fit their needs. The proposed decision

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12 matrix could also be adapted to meet the speci fic needs of individual school districts throughout the State of Florida.

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13 CHAPTER 1 INTRODUCTION Background Heating Ventilating and Air Conditioning (HVAC) systems are very complex and require careful design considerations in order to provide a heal thy, safe, and comfortable environment for the buildings occupants. Each project has a unique set of criteria that should be considered during the design phase in order to select the most appropriate system for the building function. During the mechanica l design phase, such design criteria will be defined based upon the owners specific requirements and needs. Once defined, engineers will examine the performance capabilities of various HVAC systems in order to see if they meet these criteria. The systems that successfully meet the desired criteria are the ones that are considered for implementation in the project. Traditionally, the HVAC system with the least initial cost is the one selected for the project. However, this may not be the most cost effective option over the life of the system. Other costs such as maintenance, energy use, and replacement costs should be analyzed in order to get a true sense of the cost of the system over its entire useful life. Objective of the S tudy This study has two objecti ves. First, a decision matrix will be proposed that may be used to assist school board and project team members in the selection of HVAC systems for new construction projects in Florida public schools. The decision matrix will contain both design selection criteria and cost criteria. As design criteria and needs vary by county throughout the state, the matrix will assist users in determining the most appropriate and cost effective system for the given building in question. A scale will be

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14 developed to rate the performance levels of each of the criteria in the matrix. Only the systems that have the greatest potential to be implemented in educational facilities will be analyzed in this study. The second objective of this study is to complete the decision matr ix for the given systems in question. A general life cycle cost analysis will be performed on these systems. Methods of evaluating and rating the design criteria will either be developed or be based upon standard industry practices. Limitations The propose d selection matrix is not intended to provide a definitive selection for the mechanical system of an educational facility. Its intention is to provide an accurate and practical to ol to aid designers and school district personnel in narrowing the choices f or the selection of the most cost effective and appropriate HVAC system for their facility. As this is a general study, the recommendations produced within should not replace the detailed life cycle cost analysis recommendations performed by engineers for a specific facility.

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15 CHAPTER 2 LITERATURE REVIEW HVAC System Selection Process HVAC systems are responsible for maintaining the desired environmental conditions of a space. This includes the control of the temperature, humidity, air movement, and quality of the air in the conditioned space (A merican S ociety of H eating, R efrigerati n g and A ir Conditioning E ngineers (ASHRAE) 2008). There is no one right system for a building and often there will be multiple systems that meet the design requirements of a proj ect (Elovitz 2002). The selection of which HVAC system will be implemented in a building is a critical decision. The responsibility of making this decision falls upon the design engineer. They must select a system that will satisfy the building program and design intent of the client (ASHRAE 2008). In order to achieve this, the design engineer should make a family of decisions that are based upon the performance of a wide range of criteria (Elovitz 2002). Criteria can be classified as either gating criteria or comparative criteria. Gating criteria are those that may be answered with a yes or a no (Elovitz 2002). These are aspects that the system in consideration will either meet or not meet. If the system in consideration does not meet the gating criteri a, it cannot be considered for the project unless the owner changes their criteria (Elovitz 2002). Examples of gating criteria include system performance, capacity, and spatial requirements. There are also many requirements that cannot be answered with a s imple yes or no response. Such criteria is comparative and involves tradeoffs (Elovitz 2002). Comparative selection criteria include first costs, operating costs, reliability, flexibility, and maintainability.

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16 For a system selection to be successful, t he criteria taken into consideration should be reflective of the priorities and goals of the owner. These project specific parameters should be included in the system analysis along with the basic design constraints (ASH RAE 2008). The design engineer shoul d collaborate with the owner to identify and organize these criteria. With the desired design goals outlined, the design engineer must next determine the constraints on the system. System constraints may include the performance limitations, available capac ity, available space, and available infrastructure of a building (ASHRAE 2008). It should also include the constructability constraints of the system such as the construction schedule and the ability to phase the installat ion of the HVAC system (ASHRAE 200 8). Ultimately the goal of the HVAC system selection process is to narrow down the many choices of HVAC systems to those that will work and those that will not work for a given project in order to find the best system for the building (Elovitz 2002). Sele ction Matrix As a means of narrowing the choices of mechanical systems, the designer may utilize a selection matrix. This matrix should present the advantages and disadvantages of each of the systems considered for a particular project (Elovitz 2002). The use of such a tool also allows for owner participation in the selection of the HVAC system (Oppenheim 1992). It forces the decision makers to assess what is important to them for a successful outcome (Janis and Tao 2009). A grading system should be appli ed to the matrix in order to obtain an analytical analysis of the systems in question (ASHRAE 2008). The American Society of Heating, Refrigerating, and Air Conditioning Engineers or ASHRAE (2008) suggests two methods of analysis. First, systems may be rat ed on their criteria performance levels with descriptive words such as poor, fair, good, and

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17 excellent. Second, a numerical method may be used to rate the systems. This allows for a quantitative result where the system with the highest value is that which is selected. An advantage with the numerical rating method is that weighted multipliers may be factored into some of the criteria if not all of the criteria carry the same weighted values (ASHRAE 2008). As with potential systems, there are numerous ways of evaluating selection criteria during the design process. There is also no one right way of presenting the results of the selection study (Elovitz 2002). Oppenheim (1992) presents a simple decision matrix for the comparison of systems which can be seen i n Table 21. Table 21 Decision Matrix for the Comparison of HVAC Systems; Adapted from Oppenheim, P. (1992). A Decision Matrix for Selection of Climate Control Equipment. National Association of Industrial Technology, 8(4), 42 46. Decision parameters Examples of system options Central four pipe system Air source heat pump Water source heat pump PTAC Costs First cost Maintenance cost Energy cost Operating cost Life expectancy Operation Noise Partial operation Humidity control Varying loads Other Future needs Space requirements Structural imp act This matrix allows for the comparison of multiple systems based upon system costs, operation, and other design parameters. These parameters are grouped together for

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18 easy comparison amongst the systems in question. A specific grading system is not outlined for use with this matrix, however, a qualitative or quantitative rating method could be applied. Ottaviano (1993) uses both the performance and numerical rating methods in his proposed matrix seen in Table 22. He associates a performance level with a number. A 1 indicates that a system has a poor performance level for the given criteria. Acc ordingly a 2 represents fair performance, a 3 represents good performance, and a 4 represents excellent performance. Table 22. Decision matrix using both performance and numerical rating. The table occurs as is in the original reference without any data in it. Adapted from Ottaviano, V. B. (1993). National Mechanical Estimator The Fairmont Press, Lilburn, GA. System numbe r Rating factors 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Ratings 4 Excellent 3 Good 2 Fair 1 Poor

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19 Table 23 provides an example of how weighting factors may be applied to the decision matrix. Each of the criteria is assigned a weight based upon the perceived importance to the client (Janis and Tao 2009). The systems are then scored on a scale of one to ten for their criteria performance levels. These scores are multiplied by the weight factor in order to determine the weighted score. The weighted scores for the selection criteria are summed in order to determine the system with the highest score. A more complex selection matrix is presented by Elovitz (2002) in Table 24. This matrix uses a combinatio n of qualitative and quantitative rating methods. A key feature of this matrix is that summary information for some of the criteria is listed in the table. For example, the Floorspace design criteria which falls under Space Considerations lists the equipment that takes up floor space in the table. This form of selection matrix is an effective way of summarizing a lot of information for comparison. Life Cycle Cost Analysis Once potential mechanical systems have been narrowed to those that will satisfy the ow ners requirements, the systems will be analyzed in order to determine which would be the most economic option. There are two economic methods commonly used to evaluate system selection: simple payback period and life cycle cost analysis. The method of sim ple payback determines the time period it will take to recoup the initial cost of implementing a more efficient system through recurring savings in energy (Janis and Tao 2009). This payback period is determined by dividing the initial extra cost of the sys tem by the annual difference in operating cost. The system with the shortest payback period will be the one selected. However, this method does not take into account all of the associated costs of owning and operating an HVAC system.

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20 Table 23. Decision Matrix with Weight Factors. Adapted from Janis, R. R. and Tao, W. K. Y. ( 2009). Mechanical and Electrical Systems in Buildings. VAV reheat VAV/Dual duct Multizone Fan coils Score Weighted Score Weighted Score Weighted Score Weighted Criteria Weigh t Comfort 8 5 40 5 40 5 40 7 56 Flexibility 6 10 60 8 48 1 6 7 42 Initial c ost 3 10 30 6 18 4 12 6 18 Energy c onsumption 6 7 42 7 42 7 42 9 54 Ease of m aintenance 6 7 42 9 54 10 60 5 30 Longevity 6 9 54 9 54 9 54 5 30 Acoustics 5 8 4 0 8 40 8 40 5 25 Total score 308 296 254 255 % score (normalized) 100% 96% 82% 83% Grade A+ B C C

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21 Table 24. System s election matrix utilizing both qualitative and quantitative rating methods Adapted from: Elovitz, D. M. (2002). "Selecting the right HVAC system." ASHRAE Journal 44(1), 2430. Heat p ump VAV with fan b oxes Multi ple r ooftops Fan coils Central / I ncrements Comfort Considerations Control options Can be flexible Highly flexible Limited Limited Can be flexible Control ty pe On/Off Modulating On/Off Modulating On/Off Noise Noticeable Quiet Quiet Quiet Note 1 Ventilation Limited Very Good Good Limited Note 2 Overhead heat Yes Yes Yes Note 3 No Glass height Limited Limited Limited Note 3 Above unit only Filtration Low Go od Good Low Good/Low Effect of failure Total local Partial everywhere Total local Either note 4 Either note 5 Space considerations Floorspace Boiler, pumps, s torage tank, MUAU shaft Shafts, boiler if gas h eat Many s hafts MUAU s haft, pumps Shafts Plenum space Least Medium Medium Least Medium Furniture placement Fully flexible Fully flexible Fully flexible Note 6 Leas t flexible Maintenance access Above ceiling On roof On roof Note 7 In rooms Roofscape MUAU, cooling tower One or two l arge RTU s Many smal ler RTUS MUAU, maybe chiller Several RTU s First Costs System cost Depending on Job and Contractor Specifics, Any of These Systems Can be Competitive Cost to add zones Moderate Low Very High Low High Ability to increase capacity Expensive Inexpensive Ex pensive Inexpensive Expensive Smoke control Separate system Adaptable Separate system Separate system Adaptable

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22 Table 24 C ontinued Heat P ump VAV with fan boxes Multi ple rooftops Fan coils Central / Increments Operating c ost Energy c ost 1 = Highest and 5 = lowest c ost Gas 3 2 4 2 4 Electric 3 4 5 4 5 Maintenance c ost Moderate Low High Low High Free cooling Adaptable Inherent Available Adaptable Available Heat recovery Inherent Inherent None Adaptable None

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23 Other costs that occur over the lif e of the system, such as operating, maintenance, and replacement costs, are hard to financially ignore. A life cycle cost analysis (LCCA) should be performed in order to determine which is the most cost effective option over the life of the building. Such a method of analysis compares the cumulative costs incurred over the life of the system from implementation through operating, maintaining and eventually replacemen t (A merican Society of Heating, Refrigerati n g and Air Conditioning Engineers (A SHRAE ) 2007). The life cycle cost method is effective in evaluating the building design alternatives that satisfy a required level of performance but may have different initial and annual costs (Fuller and Peterson 1996). The life cycle cost for a building system is c alculated by discounting future costs back to a present value equivalent. Only those costs that are relevant and significant to the decision need to be included in the life cycle cost analysis. Costs are considered to be significant when they are large enough to affect the life cycle cost of a project alternative (Fuller and Peterson 1996). Once these significant costs have been identified, cost data must be obtained in order to compute the life cycle cost analysis. The initial first costs for a project are the easiest to obtain since they occur in the present (Fuller and Peterson 1996). First cost data may be obtained from suppliers and manufacturers or construction cost estimating guides. Replacement costs may be estimated by assuming the future costs are equivalent to the initial costs (Fuller and Peterson 1996). These future costs are then converted into a present value. The estimation of energy costs requires the calculation of the fuel used by the system. Computer simulations may be used to estimate a buildings annual energy usage. The annual energy costs are then obtained by multiplying energy usage and energy prices.

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24 The maintenance and repair costs of a system are more difficult to estimate than other system expenditures due to varying operating sch edules and standards (Fuller and Peterson 1996). It is therefore important to use engineering judgment in the estimation of these costs. Maintenance cost may occur consistently on an annual basis or they may change at some estimated rate per year (Fuller and Peterson 1996). They may be computed from cost estimating guides or obtained from direct quotes from contractors and vendors. Florida Statutes According to Section 1013.37(1)(e) of the Florida Statutes, a life cycle cost analysis shall be performed for new educational facility construction projects with a total air conditioning load of 360,000 BTUs per hour (30 tons) or greater ( Florida Department of Education ( FLDOE ) 2003). In this LCCA, at least three schemes of HVAC systems shall be analyzed. Of these three schemes, one is required to be a centr al system (FLDOE 2003). The Life Cycle Cost Guidelines for Materials and Building Systems for Floridas Public Educational Facilities report produced by the Florida Department of Education (1999) lists the pos sible HVAC system types that may be considered in the analysis. This report only describes the characteristics of potential HVAC systems and does not provide any costing information. The system type with the lowest life cycle cost will be the system that i s installed in the new facility (FLDOE 2003). However, if any system alternatives are within four percent of the lowest life cycle cost, the school district may make the final system selection from the systems that fall within that range (FLDOE 2003).

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25 CHAP TER 3 METHODOLOGY Introduction There are many different types of HVAC systems that may be utilized in the construction of Florida public educational facilities. The selection of the mechanical system to be used is a critical decision and requires the consi deration of many different aspects. The designer must work with the school district to select the most appropriate system that will fulfill both the owners requirements as well as meet all associated building codes. In order to do this, a wide variety of design criteria should be taken into account during the design process. An effective way of presenting this information for the comparison of different HVAC systems is through the use of a selection matrix. The first objective of this thesis was to develop a decision matrix that can be used as a tool to assist school board and project team members in the selection of HVAC systems for the construction of new public educational facilities in Florida. In order to provide an effective to ol, the characteristics of the S tate of Florida needed to be considered and understood. Florida is a large state that is comprised of varying sized counties. Accordingly, school districts are also various sizes. Some counties are located along the coast while others are located further inland. Some counties are rural, while other locations have large population centers. Finally, educational facilities vary in size throughout the state. Elementary and middle schools are a different size than high schools Selection of Decision Mat rix Criteria The first step in the process of developing a decision matrix was to determine which system selection criteria should be used. The criteria selected should reflect both

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26 cost and design parameters in order to provide an effective means for the selection of the most appropriate and cost effective HVAC system. The following are the criteria that were selected for use in the decision matrix. Life Cycle Cost Criteria The associated costs of a system over its useful life are key factors in the selection process. Florida Statutes require that a life cycle cost analysis be performed on at least three different HVAC system types as part of the selection process. As such, the associated costs that comprise the life cycle cost of a system should be inclu ded in the decision matrix. The major categories of the costs that occur over the life of an HVAC system are First Cost, Energy Cost, Maintenance Cost, and Replacement Cost. These cost criteria are defined as follows: First Cost. This is the initial capit al cost of materials and installation of an HVAC system. Energy Cost. These are the costs associated with running the HVAC equipment on a day to day basis. This includes the electricity cost to operate a system during regular and demand hours. Maintenanc e Cost. This is the cost associated with performing regular preventative maintenance on the system so that it will perform at its optimal level. Such tasks include changing filters and cleaning coils. Replacement Cost. This is the cost associated with repl acing any of the equipment associated with an HVAC system over the useful life of a building. It includes the costs to replace the unit at the end of its life as well as the costs to replace any miscellaneous equipment throughout the life of the unit.

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27 Life Cycle Cost. This is the cost of the system over its entire useful life. It includes the systems first cost, yearly energy and operating cost, yearly maintenance cost, and replacement costs. The annual costs were converted to a present value in order to compare system costs. Design Selection Criteria Costs are not the only criteria that need to be considered in the selection process. Project specific parameters dictated by the owners needs should also be considered. There are a wide variety of design crit eria that may be analyzed during the selection process. The needs of educational facilities were considered during the selection of these parameters. The following factors, denoted as O ther criteria, were determined to be most relevant project specific parameters for Florida educational facilities. Life of the Unit. This is the average useful life of an HVAC unit. The useful life of a unit will dictate how many times it needs to be replaced over the life of a building which can affect the life cycle cost of a system. Required Space. This is the space needed to house the HVAC system. This includes the footprint of the unit as well as any mechanical rooms needed to house any associated ductwork and piping in the system. The required space of the system needs to be accounted for in the design of the facility because some smaller building footprints might not be able to support a large system. Complexity of the System. This is the technological sophistication of a system. This should be considered during the design phase as some counties may not be able to support sophisticated systems. Location may limit the availability of qualified maintenance and service personnel needed to maintain the system.

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28 Noise. This reflects how much noise the system generates duri ng operation. The noise produced by a system is relevant to quality of the learning environment and will also dictate design requirements. Acceptable sound levels in classrooms is critical for a proper learning environment (ASHRAE 2007). The American Natio nal Standards Institute (ANSI) Standard S12.60.2002 requires a maximum background sound level of 35 dB in classrooms (Siebein and Lilkendey 2004). Temperature Control. This is the level of control the system has in maintaining the desired air temperature of the conditioned space. This can affect the comfort level experienced by the rooms occupants. Humidity Control. How well the system can control and regulate the humidity within the conditioned space. This parameter needs to be addressed in order to main tain a proper level of air quality in the conditioned space. Organization of HVAC Systems The next step in the process of developing a selection matrix was to determine which HVAC systems to analyze in the study. The 1999 edition of the Life Cycle Cost Gui delines report produced by the Florida Department of Education was used as a starting point in this process. Part 3 of this report outlines the systems that have been implemented in Florida public schools This list was analyzed and any outdated configurat ions were discarded as options for use in this study. Any systems that were similar in nature were combined. Systems not included in the 1999 report but with potential to be implemented in educational facilities were included in the study. A list of the sy stems that were analyzed in the study can be seen in Table 31. With the HVAC systems in consideration defined, they were then grouped into sections of similar system types to better allow for the comparison of the associated life

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29 cycle costs and decision cr iteria. Direct Expansion or DX s ystems were analyzed first. These types of systems are decentralized and are often suitable for smaller projects. This section was follow ed by Chiller s ystems. Chillers are centralized systems and are often used for larger facilit ies. Finally, Air Distribution s ystems were analyzed. These systems use various methods to distribute air throughout the conditioned space and can be used with DX and C hiller systems. Table 31 HVAC systems included in study System c lassificatio n Unit t ype DX s ystems Wall mounted unit Package rooftop Split systems Water loop heat pump Geothermal heat pump Chiller s ystems Air cooled chiller Water cooled chiller Air Distribution s ystems Constant volume Variable air volume (VAV) Fa n coil units Development of Decision Matrix With the decision criteria defined and the systems classified, the next step was to create a matrix that would effectively display the information. Features of the selection matrices presented in the literatur e review were combined to create a matrix that was appropriate for the intended application. The selection criteria categories of Costs and Other were clearly outlined for easy reference. A method of rating the performance of the selection criteria was developed in order to rate the HVAC systems in question. A combination of numerical ranking and color coding was used to compare the performance levels of the system selection criteria. The number scale was used to rank the performance of the unit types within each selection criteria category. For each criterion, the unit types were numerically

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30 ranked according to the nu mber of systems in each system classification. For this study, the DX and Chiller systems were combined into one system classification. These units are the primary sources of conditioned air. By grouping them into one system classification allowed these HVAC units to be compared against each other. The Air Distribution systems were ranked in a separate system classification. These systems are m ethods of distributing conditioned air and are therefore not directly comparable with the DX and Chiller systems. A ranking of 1 denoted the best option for a given criterion. For example, in the DX and Chiller system classification there were seven syst ems being analyzed. Each Cost and Other criterion was ranked on a scale from 1 to A ranking of 1 denoted the best unit type for the criteria in question. A tie within this scale indicated that a significant difference between systems could not b e discerned. Weight factors were not used in this scale as the owners requirements will vary. However, the owner may apply a weight factor to this scale for use in the selection of equipment if they desire. The color scale rated the units within each syst em classification over a range of performance levels This scale varied for each of the criteria in question and will be described in the Data Chapter. The color coding was used to categorize each criterion into three levels. Each level was represented by a different color: green, orange, or red. For the Cost criteria, low costs were represented by green, moderate costs were represented by orange, and high costs were represented by red. Each cost criterion had different cost ranges. Therefore, the color coding scale for each cost criterion was determined based on the range of the data collected. For the Other criteria the color green signified that a system exceeded average performance levels for the given

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31 criteria. Orange represented an adequate performa nce by the system for the given criteria. Finally, red indicated that a system performed below average performance levels. These levels applied on an overall basis. An example of both the numerical ranking and color coding can be seen in Table 32. Life Cy cle Cost Analysis The second objective of this thesis was to complete the decision matrix for the HVAC systems in question. A general life cycle cost analysis was performed in order to fill in the cost portion of the decision matrix. Data for this analysis was collected from a variety of sources. School districts, general contractors, mechanical contractors, and engineers were consulted for cost data. Once collected, any future costs were converted into a present value. Table 33 shows the life cycle cost p arameters that were used in the computati on of the present value of the system costs. Table 33. Life cycle cost parameters Life cycle cost parameter Value Building service life 50 years General inflation rate 2 .0 % Energy inflation rate 4 .0 % Non energy d iscount rate 2.7% Energy discount rate 3.0% The present value of future c osts were computed using Equation 31. For costs that occur on an annual basis, such as energy and maintenance costs, this equation was used to compute the present value of t he annual cost for each year over the life of the building. The present value of each year was then summed to get the total present value for such an annual cost. For costs that occur periodically throughout the life of the building, such as unit replaceme nt costs, this equation was used to compute the present

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32 Table 32. Example of the proposed decision matrix displaying the color coding and ranking of systems Costs Other Unit type First cost Energy c ost Maintenance cost Replacement cost L CC Required space Complexity Life of unit Noise Temperature control Humidity control System A 1 3 2 1 2 1 1 3 3 3 3 System B 2 2 1 2 1 2 3 2 2 2 2 System C 3 1 2 3 3 2 2 1 1 1 1

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33 value for the year at which the cost was incurred. If multiple replacements occur r ed over the life of the building, these were summed to get a total present value for the periodic costs. Equation 3 1 Where: P = Present cost F = Present value of f uture cost i = Inflation r ate d = Discount rate n = Number of periods Th e following are descriptions of how the cost data was collected and converted into a cost per ton for system comparison. Once the costs were in a similar units they could be ranked according to the method described previously. Any future costs were convert ed into a present value. First Costs Attempts were made to collect first cost data from manufacturers, engineers, RS Means, and contractors. However, data was not obtained from all of these sources. Major manufacturers of HVAC equipment do not produce i nformation on the total installation costs of mechanical systems. The Trane Company (1991) previously published the Systems Manual which gave general costing information for different types of systems in different types of building. A copy of this publicat ion was able to be obtained, however it was over 15 years old and therefore outdated. The engineers consulted during the study recommended using RS Means to obtain material and

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34 installation costs. RS Means CostWorks (2010) was consulted for data to be used as a comparison of quotes received from contractors. Local mechanical contractors were contacted in order to receive pricing quotes. It was found that these contractors did not maintain a database of approximate prices, such as cost per square foot or cos t per cost per ton, for HVAC systems. This is due to the uniqueness of each mechanical system. Given this situation, the best way to obtain first costs was found to be by reviewing actual pricing quotes on pieces of equipment from manufacturers. These manu facturer quotes only included the cost to furnish the equipment. Installation costs were not included in these prices. Many of the quotes reviewed contained multiple pieces of equipment, however only lump sum prices were listed. This made it difficult to extract the actual costs of the equipment. The manufacturer quotes that were able to be used to compute the cost per ton of equipment are considered to be proprietary information. As such, they cannot be printed in this study. In order to get costs, the tot al value of the equipment was divided by the tonnage of the system it was serving. This gave a cost per ton for the piece of equipment. It was not possible to obtain a large sample of quotes for each of the systems in question. Where multiple quotes were available, the costs were averaged. This average cost was used as the first cost for the material of the unit. However installation costs for the unit needed to be calculated. The daily labor output found in RS Means CostWorks (2010) was used in the comput ation of the installation cost of the unit. Equation 3 2 was used to calculate the total installation cost of the unit. It was assumed that the hourly

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35 labor rate for an installation crew was $75.00/hr. For an eight hour work day this equated to a $600/day labor rate. Equation 3 2 The total labor cost of the unit was divided by the approximate unit tonnage to get the labor cost per ton. The unit material cost per ton determined from the supplier quotes was added to the labor cost per ton t o get the total first cost per ton for the unit These costs were compared to the costs found in RS Means CostW orks (2010) in order to determine if this was a reliable source for costing information. It was found that the material costs of the units in RS Means were not comparable to the costs of the supplier quotes. For the systems where no supplier costing information was able to be obtained, the first costs for the systems were based off of general quotes obtained from one of the mechanical contractors that was contacted during the study. Their quotes included the costs to furnish and install the unit. For the DX Systems and Chiller Systems the first costs only included the cost per ton to furnish and install the HVAC unit itself. The costs of ductwork or means of distributing air were not included in these systems first costs. The first costs for the methods of distributing air were included in the Air Distribution System section. This was done since the methods of distributing air may be applied to any one of the HVAC units in question. For the Air Distribution systems, the costs were done on a cost per unit basis rather than a cost per ton basis. This was done since different quantities of VAV boxes and FanCoil units will be used for different system s. It was also assumed that the Constant Volume method of air distribution was the baseline cost for all air

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36 distribution systems. As such, its first cost was considered to be zero. Ductwork is needed to supply air to the conditioned space in all of the methods of air distribution. For similar sized systems the ductwork to supply the air should be relatively the same size. The only cost difference will come from the air terminal units. The first costs presented only included the cost to furnish and install the equipment. Tax, overhead, and markups were not included in these costs. Since school districts are public entities, they are eligible for the Direct Purchase Program. This program allows the school district to purchase the materials for the project tax free from suppliers. The first costs of the systems that were obtained did not need to be converted because they were already in present value form. Costs of systems installed in Florida public s chools An attempt was also made to collect the actual HVA C system costing information for schools that have been recently built in the State of Florida. However, costing information for only two elementary schools in Pasco County Florida was able to be obtained. These costs were the actual prices that were paid by the state for construction of the school. Both of the elementary schools had an air cooled chilled water system with Variable Air Volume (VAV) boxes in place. This allowed for the approximate comparison of prices for this type of system. The prices that were able to be obtained included: Cost to purchase the chillers Cost to purchase the air distribution system Total material costs (through the Direct Purchase Program) Total mechanical contractor costs Total building Costs The total square footage of the school and tonnage of the chillers were also obtained for the schools in question. With this data, the cost per ton for the chillers was

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37 able to be calculated. Both the total material costs and the total fees for the mechanical contractor were divided by the tonnage of the system to get an approximate cost per ton. The total material costs were compared to the total mechanical contractor costs to get an approximate percentage of the material costs to the costs for installation of the system as a whole. A percentage difference was also calculated between the total cost for the mechanical system (summation of the material and contractor costs) and the total building cost. Since the costing information for only a few schools was able to be obtained and it was for only one of the systems in question, this data was not able to be used in the life cycle cost analysis. The costing information for these schools may be found in Appendix A. Energy Costs Energy costs for the systems were computed by doing approximate hand calculations. More detailed energy calculations may be obtained for a system through the use of computerized energy models. However, such programs require the input of a design of a building. Since this is a general study and no set building design w as being used, an energy model was not used to calculate the energy consumption of the HVAC units. The computed annual energy costs were converted to a present value using Equation 3 1. Water consumption charges were not included in this study. The energy consumption costs for the HVAC units were computed by using the recommended system efficiency rate given by the U.S. Department of Energy s website These efficiency rates are greater than the base rates that are dictated by ASHRAE Standard 90.1 but they are not the most efficient options available on the market (USDOE 2008). For DX systems, the efficiency was given in terms of an energy efficiency ratio (EER). The EER was converted into kW per ton by Equation 3 3

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38 Equation 3 3 The amount of hours that the system operates during the year needed to be obtained to compute the energy costs. Systems do not always operate at their full load throughout the entire year. Full load operation is only needed during the time of the year where peak building cooling loads are experienced. Systems normally operate at partial load levels throughout the majority of a year. These partial operating loads may be converted into an equivalent number of hours that the system would have run if it only operated at its full load. This number of hours is known as the equivalent full load operating hours (EFLOH). The EFLOH can then be used to calculate system energy costs. The actual equivalent full load operating hours for a system will vary based on the overall design of the school and the schools cooling and heating demands. The EFLOH for a particular system design may be obtained by running energy modeling programs. The value obtained will be a constant for the particular school design and will be used to comp ute the energy costs for any systems that are considered for installation. For this study, it was assumed that the EFLOH was 2000 hours as there was no set school design. Assuming the equivalent full load operating hours allowed for the relative magnitude of unit electricity costs to be established. The cost of electricity used was $0.15/kWh. This is the average rate of electricity for Gainesville, Florida and includes demand charges. The annual energy costs of the systems were calculated using Equation 3 4 Equation 34

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39 Energy costs were only computed for the HVAC units themselves. All other associated equipment was neglected for this study. Equipment such as pumps, air handlers, or cooling towers will consume electricity. However, the number and size of such equipment will be dependent on the system design. Energy costs for the air distribution systems were not calculated for this study. The methods used to distribute air can affect the amount of energy used by the HVAC unit however, exac t costs are design dependent and would need to be calculated through the use of a computer energy model. In general, the method of VAV can reduce energy costs from 10% to 20% over constant volume systems (USDOE). This is because the VAV box varies the amount of air that is supplied to a space. This leads to reduced costs to operate the fans in the system. Maintenance Costs Maintenance costs were obtained by receiving general quotes from a mechanical contractor in the Gainesville area that performs regular maintenance services for local schools These quotes were reflective of the costs to perform regular preventative maintenance. Such maintenance includes changing filters, lubricating bearings and motors, and inspecting all equipment and controls. These quotes were based on the contractors experience and were reflective of an approximate cost without a system design. Maintenance costs will vary based on the quantity and type of equipment, the equipment location and access, system complexity, and whether th e units are located in a harsh env ironment (ASHRAE 2007). This annual cost was converted to a present value using Equation 3 1. Maintenance Costs were not available for the Air Distribution Systems category. According to the quotes received from the mechanical contractors,

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40 typical maintenance contracts do not include regular servicing of the devices employed to distribute air. Replacement Costs The replacement costs were divided into the costs to replace the HVAC unit at the end of its useful life and the costs to replace miscellaneous equipment over the life of the HVAC unit. These two costs were totaled in order to determine the total present value of the unit replacement costs. Replacement of HVAC u nits The cost to replace an HVAC unit would only include the price of the unit and the labor to install it. Thus, the replacement costs for the units were assumed to be the same price as the first costs of the units. These costs would occur at the end of the useful service life of the unit. The year(s) of repl acement was determined based upon the life of the unit which is discussed in the Design Criteria Analysis section. For Air Distribution Systems, it was assumed that the associated ductwork and grilles would not be replaced during the life of the building. However, the VAV boxes and FanCoil units would need to be replaced over the life of the building. These were the only costs associated with the replacement of the Air Distribution Systems. The replacement costs of HVAC units are periodic costs and were co nverted into a present value using Equation 3 1 Replacement of miscellaneous equipment The costs to replace miscellaneous system equipment reflects the costs to replace equipment that is needed in order for the HVAC system to work, but is not critical en ough to cause the unit to be replaced. These costs are difficult to predict. For this study it was assumed that the cost to replace miscellaneous equipment was 6% of

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41 the system first cost. This is an annual cost over the life of the unit except for the fir st year after installation. The contractor and/or manufacturer will normally provide the first years parts and labor warranty. Life Cycle Cost The life cycle cost was determined by summing the present worth values of the first costs, energy costs, mainte nance costs, and replacement costs. The HVAC unit types in the DX and Chiller system classification and the Air Distribution system classification were then ranked according to the scale described previously. Design Criteria Analysis The design criteria were evaluated by either developing simple rating methods or by using standard industry practices. The following are descriptions of how the design criteria were collected and calculated. Required Space The required space of the system was based upon the siz e and location of major system components. A rating method needed to be developed in order to allow for the ranking of the systems. The DX and Chiller systems were analyzed separately from the Air Distribution s ystems for this design criterion. First, typ ical design layouts for the systems were examined, and their space characteristics were summarized in a table. For the DX Systems and Chiller Systems, the summary table listed the typical size of the unit, any associated equipment, the placement of the uni t and associated equipment, required piping, required ductwork, and mechanical rooms needed. Approximate dimensions of HVAC units were found by looking at manufacturer specifications of typical unit sizes. This summary table was used to complete a rating table that was used to compute an average score for the

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42 requir ed space of the DX and Chiller s ystems. The systems were rated on the size of the unit, the piping in the system, the mechanical room space required, and the outdoor space required. These criter ia were rated on a scale of one to three with one being the least amount/space and three being the most. Exact descriptions of the rating criteria are given in the Data chapter. An average value for each system was taken and the systems were ranked accordi ng to these averages. The summary table for the Air Distribution s ystems listed any associated equipment, the approximate size of that equipment, the required piping, and the equipment placed in the ceiling space. A unit size was not associated with this rating since the air distribution methods may be applied to any one of the HVAC units. This summary table was used to complete a rating table that was similar to the one used for t he DX and Chiller systems. The Air D istribution systems were rated on the amount of piping needed and the amount of equipment located in the ceiling space. An average value for each system was taken and the systems were ranked according to these averages. Complexity The complexity of the system was based upon the number of major components that needed to be installed and how many points of maintenance the system has. The summary tables that were created in determining the required space of the systems were referred to in the rating of the systems. Each characteristic was rated on a scale of one to three and were then averaged in order to determine a ranking of the systems. Life of the Unit There is no exact science to predicting the useful life of an HVAC unit. Service life will be dependent upon a number of factors that are hard to accurately predict. Among

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43 these factors is how well the system is maintained throughout its life and whether the unit is located in a corrosive environment (ASHRAE 2007). The 2007 ASHRAE Applications Handbook provides a table of median service life for mechanical equipment. This table lists the estimated service life for various HVAC system components that was based upon a 1978 ASHRAE funded research project by Akalin. However, ASHRAE warns that these estimates may be outdated due to changes in technology, materials, manufacturing techniques, and maintenance practices (ASHRAE 2007). As such, ASHRAE funded a project to develop an internet database to collect HVAC equipment service life which was based on the findings of Abramson et al. (2005). From these findings, survival curves were able to be created giving the median service life for the HVAC equipment. These curves reflect the units still in service for a given age and the units that ar e replaced at each age (ASHRAE 2007). The median service life indi cates the highest age that the survival rate stays at or above 50% while the sample size is 30 or greater. At the time of this study, there was not enough data to create accurate survival curves for all of the equipment in consideration. The estimated ser vice life for HVAC equipment was analyzed in a variety of ways for this study. The findings of the methods tried during the study are summarized in Chapter 4. First, a literature review was conducted in order to determine the estimated service life recommended in HVAC design references. Through the literature review, it was found that service life was generally given in a range of years. Also, most of the available HVAC design references were over fifteen years old (Colen 1990; Ottaviano 1 993; A kalin 1978). As stated previously, these estimates may be outdated and not accurately reflect the mean service life of equipment.

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44 Next, the internet database created from Abramson et al.s (2005) findings was examined for potential use in the estimation o f median serv ice life (ASHRAE 2010 ). The database allows users to search for equipment through a variety of criteria. Among these criteria are system type, building type, and state. A search was conducted to determine if there was equipment service life information for schools from the State of Florida. This search returned zero matches. Another search was conducted to determine how many pieces of equipment from the State of Florida were available in the database. This search returned 1470 equipment matches. From there a search on the pieces of equipment in schools was conducted which returned 3,620. Individual equipment types were analyzed to determine the available data. It was found that the differences on the available data for each type of equipment varied significa ntly in total pieces of equipment and location. It was concluded that statistically accurate median service life data could not be extracted for the means of this study from this database because of these differences. The mechanical contractors that were asked to provide cost quotes were also asked to provide an estimate on equipment service life for the study. However such opinion based surveys produce age at replacement information (Hiller 2000). Replacement of units can be for a number of reasons including failure, reduced reliability, excessive maintenance costs, or changed system requirements (ASHRAE 2007). The age of replacement of units is different from the equipment service life (Hiller 2000). Finally, the Median Service Life tables found in Chapt er 36 of the 2007 ASHRAE Handbook HVAC Applications were analyzed. These tables listed the median service

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45 life of equipment from the ASHRA E funded research projects by A kalin (1978) and Abramson et al. (2005). The available median service life from Abram sons (2005) study was compared to the median service life given by A ka lin (1978) It was found that most of the differences were on the order of one to five years, with Abramson et al.s findings having the longer median service li fe (ASHRAE 2007). The result of Abramson et al.s (2005) findings was deemed to be the most accurate estimate of equipment service life for this study since the results were based upon survival curves. However, at the time of this study, there was not enough data available to cre ate survival curves for all the equipment in question. The median service life for the equipment that was available was used as the life of the unit for this study. All other unit lives were taken from the ASHRAE table. These median service life values wer e consistent with the other sources examined and are the most credible source until more data is collected from the internet database. Noise Noise generated by HVAC systems may be caused by a number of factors. Most of these factors are determined by the design of the HVAC system. The HVAC units generate noise during operation which may be transmitted to the space through the air, walls, windows, doors, ductwork or ceilings (Siebein and Lilkendey 2004). Noise may also be generated in the ductwork as air tr avels through it. There are a number or methods that may be employed to reduce the noise generated by HVAC systems, but they specifically pertain to the systems design. ANSI Standards mandate that the maximum background sound levels for classrooms be equal to 35 dB or less. The design professional must take measures to reduce the noise generated by HVAC system operation in order to meet the required background sound levels.

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46 Since the noise heard in the classrooms is dependent upon system design and this is a general study, the units were rated based on their potential to produce noise in the classroom. This was done by analyzing the system components that generate noise during operation and their relative location to the classroom. A summary table was crea ted to highlight the system noise characteristics. The summary table listed the equipment located within the classroom space, equipment near the classroom space, and any other potential sources of noise in the classroom. This summary table was then used in the rating of the systems potential to generate noise in the classroom. The systems were rated on the sources of noise in the classroom, near the classroom, and other potential noise. Each noise characteristic was rated from one to three with one being no noise, two being a potential noise source, and three being a noise source. An average value for each noise characteristic was taken and the systems were ranked according to these averages. Temperature Control The comfort level in the conditioned space d epends on the temperature and humidity of the supply air, the velocity of the supply air as it leaves air terminals, and the movement of air throughout the conditioned space. These are all factors that are attributed to the design of a system as a whole. T he individual HVAC units are responsible for conditioning the air to the required temperature and humidity specifications needed based on the cooling loads of the building. The units that are installed are selected based upon these specifications. The proc ess of regulating temperature falls more under the method used to distribute the air throughout the space. As such, only the Air Distribution systems were rated on their ability to control the temperature of the conditioned space. The required space design criteria was

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47 removed from the DX and Chiller system decision matrices since it is not applicable to the units themselves. The Air Distribution systems were ranked according to their ability to control the comfort level of multiple rooms throughout the conditioned space. This was dependent on the thermostat control type. Humidity Control Humidity control is related to the amount of ventilation that is provided for the conditioned space. ASHRAE Standards require that classrooms have a minimum of 15 cfm per person of ventilation (ASHRAE 2007). Ventilation is provided by supplying fresh outdoor air to the space in order to remove indoor air pollutants generated by the rooms occupants. Schools have a high occupant density which in turn results in large volumes of outdoor air having to be supplied to the conditioned space (Fischer and Bayer 2003). Florida has a very humid climate and this can put strain on the HVAC system to properly condition the large levels of required ventilation air. Conditioning large vol umes of ventilation air must be taken into account during the design on the HVAC system of a building. Some systems may experience part load humidity build up during operation. This occurs as the unit cycles on and off. The moisture that condenses on the coiling coil during operation may evaporate back into the air stream when the coiling coil is cycled off unless the condensate pan is correctly sloped and the condensate drains properly from the pan. The full latent capability of the unit is realized when the cooling coil reaches its design temperature. Part load build up of humidity is dependent upon the design of the system as a whole. For this general study, a method for rating the systems on their ability to remove humidity in the space was unable to b e created. As such, this design criterion was removed from the decision matrix for all of the systems in question.

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48 CHAPTER 4 DATA The following is the data that was collected during the study in order to complete the decision matrix presented in the previ ous chapter. Cost Criteria First Costs Table 41 lists the cost per ton for DX and Chiller units that was able to be obtained from looking at equipment quotes. This table also show s the computation of the installation costs of the units. These labor costs were based on the daily output given in RS Means. Equation 4 1 was used to calculate the total labor cost to install the unit. Equation 41 Table 41. First c osts of DX and Chiller units based off of actual supplier quotes Unit material c ost per ton Daily output L abor rate ($/day) Total unit labor cost Labor cost per ton Total first cost per ton of the unit Wall mounted unit $ 1,065.00 4 $ 600.00 $ 150.00 $ 150.00 $ 1,215.00 Split system $ 633.00 $ 838.00 $ 960.00 $ 810.33 0.5 $ 600.00 $ 1,200.00 $ 240.00 $ 1,050.33 Air cooled chillers $ 454.00 $ 431.00 $ 442.50 0.21 $ 600.00 $ 2,857.14 $ 19.05 $ 461.55 Wate r cooled chiller $ 495.00 0.13 $ 600.00 $ 4,615.38 $ 30.77 $ 525.77 It was assumed that the hourly labor rate for an installation crew was $75.00/hr. For an eight hour work day this eq uated to a $600/day labor rate. The total labor cost to install

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49 the unit was divided by the approximate unit tonnage to get the labor cost per ton. The material cost per ton determined from the supplier quotes was added to the labor cost per ton to get the total first cost per ton for the unit Table 42 shows the calculations of the first cost per unit of the Air Distribution devices The unit material costs were obtained by looking at equipment quotes from suppliers. The labor rate to install the units a nd the total unit first cost was calculated in the same manner as the DX and Chiller units. The first costs for these system types were done on a cost per unit basis rather than a cost per ton basis because different quantities of VAV boxes and FanCoil un its will be used for different systems. It was assumed that the Constant Volume method of air distribution was the baseline cost for all air distribution systems. As such, its first cost was considered to be zero. Ductwork is needed to supply air to the conditioned space in all of the methods of air distribution. For similar sized systems the ductwork to supply the air should be relatively the same size. The only cost difference will come from the air terminal units. 4 2. First c ost of Air Distribution dev ices based off of actual supplier quotes Material c ost per unit Daily o utput Labor r ate ($/day) Total labor c ost per unit Total unit first c ost VAV $ 630.00 $ 643.00 $ 746.00 $ 673.00 9.00 $ 600.00 $ 66.67 $ 739.67 Fancoil $ 1,119.00 $ 1,437.00 $ 1,278.00 7.00 $ 600.00 $ 85.71 $1,363.71

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50 Since not all of the first costs of the DX systems in the study were able to be obtained from actual supplier quotes, Table 4 3 shows the quotes that were obtained from a local mechanical contractor for a general estimate on the cost to furnish and install DX units. Table 43.General quotes of the installation cost s of DX systems Unit t y pe First cost of u nits (5 ton) First cost per t on DX Systems Wall m ounted u nit $5,000.00 $1,000.00 Enhanced Wall mounted u nit $7,400.00 $1,480.00 Package rooftop electric $5,800.00 $1,160.00 Package rooftop Gas $6,500.00 $1,300.00 Split systems $6,500.00 $1,300.00 Enhanced split system $7,800.00 $1,560.00 Water source heat pump $4,500.00 $900.00 Geothermal heat pump $6,200.00 $1,240.00 An enhanced unit is one that provides ventilation as well as conditioned air For this study, the cost of the basic unit was used. Table 44 gives a summary and ranking of the first cost per ton of the DX and Chiller systems that were used for this study. Table 45 gives a summary and ranking of the first cost per unit for the A ir Distribution systems. The first costs listed for these systems were rounded to the nearest ten dollars of the calculated costs. This was due to the accuracy that was able to be obtained from the data. Energy Costs Table 46 and Table 47 show the calculation of the unit energy cos ts over the life of the building for the DX and Chiller systems. These costs only reflect the energy usage of the units themselves. The energy usage of other associated equipment, such as air handlers, pumps, or cooling towers, have been neglected in the c alculations. These are only estimated energy costs to show the relative magnitude of energy savings from systems with a higher efficiency. Water consumption charges were not included in this

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51 study. The energy costs of the Air Distribution systems were not calculated for this study as they will be dependent upon the design of the school. Table 44. Summary and ranking of the first c ost per ton for DX and Chiller systems Unit t ype First c ost ($/ton) Rank DX s ystems Wall mounted unit $ 1,220.00 6 Pa ckage rooftop $ 1,160.00 5 Split system $ 1,050.00 4 Key Water loop heat pump $ 900.00 3 $0 to $600 Geothermal heat pump $ 1,240.00 6 $601 to $1000 Chiller systems Air cooled chiller $ 460.00 1 $1001 and up W ater cooled chiller $ 530.00 2 Table 45. Summary and ranking of the first cost per unit for Air Distribution systems Unit type First cost ($/unit) Rank Key Air Distribution systems Constant volume $ 1 $0 to $500 VAV box $ 790 .00 2 $501 to $1000 Fan coil unit $ 1,360 .00 3 $1001 and up The unit efficiency rates used in the calculations were taken from the U.S. Department of Energys website (USDOE ). These recommended rates are greater than the base rates that are dic tated by ASHRAE Standard 90.1 but they are not the most efficient options available on the market. For the DX systems, the efficiency was given in terms of an energy efficiency ratio (EER). The EER was converted into kW per ton by Equation 42. Equation 42

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52 Table 46. Calculation of energy costs of DX units Unit type EER kW/ton Cost per kWh Annual EFLOH operating hours kWh per ton per year Annual Energy Cost per ton Inflation r ate (%) Discount rate PV energy cost over 50 years DX systems Wall mounted unit 11 1.09 $0.15 2000 2182 $330 4% 2.7% $ 21,111 Package rooftop 11 1.09 $0.15 2000 2182 $330 4% 2.7% $ 21,111 Split systems 12 1.00 $0.15 2000 2000 $300 4% 2.7% $ 19,192 Water loop heat pump 12 1.00 $0.15 2000 2000 $300 4% 2.7% $ 19, 192 Geothermal heat pump 14.1 0.85 $0.15 2000 1702 $260 4% 2.7% $ 16,663 Table 47. Calculation of energy costs of Chiller systems Unit type kW/ton Cost per kWh Annual EFLOH operating hours kWh per ton per year Annual energy cost per ton In f l ation rate (%) Discount rate PV e nergy cost over 50 yrs Chiller systems Air cooled chiller 0.98 $0.15 2000 1960 $290 4% 2.7% $ 18,55 2 Water cooled chiller 0.49 $0.15 2000 980 $150 4% 2.7% $ 9, 596

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53 For this study, it was assumed that the units operated for 2 0 00 equivalent full load operating hours The cost of electricity used was $0.15/kWh and this included demand charges The annual energy costs of the unit s we re calculated using Equation 43 Equation 43 The annual energy costs listed for these systems were rounded to the nearest ten dollars of the calculated costs due to the accuracy of the available data. The present value of this annual cost was computed for each year over the life of the building. These present values were summed to get the total present value of the unit energy cost over the 50 year building life These calculations can be found in Appendix B. Table 48 gives a summary and ranking of the cost per ton for the HVAC units. Maintenance Costs Table 49 shows the calculation of the unit maintenance costs over the life of the building for the DX and Chiller systems. These costs were based off of general quotes from mechanical contractors to perform regular preventative maintenance on the units such as changing filters, lubricat ing bearings and motors, and inspecting all equipment and controls. The maintenance cost of the Air Distribution systems were not included in this study as normal maintenance contracts do not include regular servicing of the devices that distribute the conditioned air. The present value of this annual cost was computed for each year over the life of the building. These present values were summed to get the total present value of the unit maintenance cost over the 50 year building life. These calculations c an be found in Appendix B. Table 410 shows the ranking of maintenance costs for the units.

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54 Table 48 S ummary and ranking of energy costs for the DX and C hiller units Unit type Annual energy cost per ton Rank DX s ystems Wall mounted unit $ 330.00 5 Package rooftop $ 330.00 5 Key Split systems $ 300.00 4 $0 $150 Water loop heat pump $ 300.00 4 $151 $300 Geothermal heat pump $ 260.00 2 $301 or greater Chiller systems Air cooled chiller $ 290.00 3 Water cooled chiller $ 150.00 1 Table 410. Summary and ranking of unit maintenance costs Unit t ype Annual maintenance cost per ton ($/ton) Rank DX s ystems Wall mounted u nit $ 160 4 Package rooftop $ 160 4 Key Split systems $ 90 2 $0 $50 Water loop heat pump $ 120 3 $51 $150 Geothermal heat pump $ 120 3 $151 and up Chiller systems Air cooled chiller $ 9.30 1 Water cooled chiller $ 9.30 1 Replacement Costs Table 411 gives the calculation of the present value of the periodic replacement costs of the HVAC uni ts. These occur at the end of the service life of the HVAC unit. The replacement costs for the units were assumed to be the same price as the first costs of the units. The year(s) of replacement was determined based upon the life of the unit. For Air Distr ibution Systems, it was assumed that the associated ductwork and grilles would not be replaced during the life of the building. However, the VAV

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55 Table 49 Present value of the cost of maintenance over a 50 year building life Unit type Annual cost for 5 ton unit Cost per year ($/ton) Inflation rate (%) Discount rate (%) PV of maintenance costs over 50 years ($/ton) DX s ystems Wall mounted unit $ 800.00 $ 160 2% 2.7% $ 6, 799 Package rooftop $ 800.00 $ 160 2% 2.7 % $ 6, 799 Split systems $ 450.00 $ 90 2% 2.7% $ 3,824 Water loop heat pump $ 600.00 $ 120 2% 2.7% $ 5, 099 Geothermal heat pump $ 600.00 $ 120 2% 2.7% $ 5,099 Chiller sys tems Air cooled chiller $ $ 9.30 2% 2.7% $ 395 Water cooled chiller $ $ 9.30 2% 2.7% $ 395

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56 boxes and Fancoil units would need to be replaced over the life of the building. These were the only replacement costs associated with the Air Distribution Systems. Table 412 shows the calculations of the cost to replace miscellaneous unit equipment. For this study it was assumed that the cost to replace miscellaneous equipment was 6% of the system first cost. This is an annual cost over the life of the unit except for the first year after installation. The contractor and/or manufacturer will normally provide the first years parts and labor warranty. The present value of this annual cost was computed for each year over the life of the building. These present values were summed to get the total present value of the miscellaneous equipment replacement cost over the 50 year building life. These calculations can be found in Appendix B. Table 4 13 gives a summary of the total replacement c osts for the DX and Chiller units. Table 414 gives a summary of the total replacement costs for the Air Distribution systems. The total replacement costs were found by summing the present value of the periodi c unit replacement costs and the present value of the miscellaneous equipment costs. Life Cycle Cost Table 415 summarizes all of the associated costs for the DX and Chiller units over the life of the building. The life cycle costs of the unit include the first costs, energy costs, maintenance costs, replacement costs. These costs were summed to get the total life cycle cost for the unit. Table 416 summarizes all of the associated costs for the Air Distribution systems over the life of the building. The only life cycle costs associated with the Air Distribution systems were the first costs and the unit replacement costs.

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57 Table 41 1 Calculation of periodic unit replacement costs Unit Type Life of unit # of replacements over 50 years Replace at year Firs t c ost per ton PV of r eplacements ($/ton) DX s ystems Wall mounted unit 15 3 15, 30, 45 $ 1,220.00 $ 2,992 Package rooftop 15 3 15, 30, 45 $ 1,160.00 $ 2,844 Split systems 15 3 15, 30, 45 $ 1,050.00 $ 2,575 Water loop heat pump 24 2 24, 48 $ 900.00 $ 1,412 Geothermal heat pump 24 2 24, 48 $ 1,240.00 $ 540 Chiller systems Air cooled chiller 25 1 25 $ 4 60.00 $ 388 Water cooled chiller 25 1 25 $ 530.00 $ 447 The replacement costs for Air Distribution systems are given in cost per unit Air Distribution system Constant volume 50 0 $ $ VAV 20 2 20, 40 $ 790.00 $ 1,290 Fan coil units 20 2 20, 40 $ 1,360.00 $ 2,221

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58 Table 412. Calculation of miscellaneous equipment costs Unit type First c ost per ton Annual m isc r eplacement costs (6% of first cost) PV of misc. replacement c osts ($/ton) DX s ystems Wall mounted unit $ 1,220 $ 73 $ 3,037 Package rooftop $ 1,160 $ 70 $ 2,888 Split systems $ 1,050 $ 63 $ 2,614 Water loop heat pump $ 900 $ 54 $ 2,241 Geothermal heat pump $ 1,240 $ 74 $ 3,087 Chiller systems Air cooled chiller $ 460 $ 28 $ 1,14 5 Water cooled chiller $ 530 $ 32 $ 1,319 Table 413. Summary and ranking of DX and Chiller replacement costs Unit Type Total PV of replacement costs per ton Rank DX s ystems Wall mounted unit $ 6,029 6 Package rooftop $ 5,73 2 5 Split systems $ 5,189 4 Key Water loop heat pump $ 3,652 3 $0 to $2000 Geothermal heat pump $ 3,627 3 $2001 to $5,000 Chiller systems Air cooled chiller $ 1,53 3 1 $5,001 or greater Water cooled chiller $ 1,766 2 Table 414. Summary and ranking of Air Distribution replacement costs Unit t ype Total PV of replacement costs per unit Rank Key Air Distribution Constant volume $ 1 $0 to $500 VAV $ 1,290 2 $501 to $2,000 Fan coil units $ 2,221 3 $2,001 or greater

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59 Design Criteria Required Space The required space of the system was based upon the size and location of major system components. Table 417 gives a summary of the space requirements for typical DX and Chiller s ystems This summary table was used in the ratings of the required space of the DX and Chiller systems which can be seen in Table 418 Each space characteristic was rated on a scale of one to three with one requiring the least space. Table 419 lists the meaning of the rating level for each of the space characteristics. Table 419. Explanation of rating system for the required space criterion Rating Criteria 1 2 3 Size of the unit Small Medium Large Piping No piping Refrigerant piping Chilled water piping M echanical room space required No mechanical room Small mechanical room Large mechanical room Outdoor equipment space required Little or no outdoor space Moderate outdoor space Large outdoor space A mount of equipment in ceiling space Basic ductwork Typica l air terminal units Large air terminal units Table 420 gives a summary of the space requirements for typical Air Distribution Systems. This table was used in the rating of the required space of the Air Distribution Systems which can be seen in Table 421. The space characteristics of a system were r ated on a level of one to three with one requiring the least space. T he meaning of the rating level for e ach of the space characteristics can be seen in Table 419. Complexity Table 422 shows the calculati on of the ranking of the complexity of the DX and Chiller systems. Table 4 17 was used as a reference in the completion of this table.

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60 Table 415. Summary and ranking of the life cycle costs for the DX and Chiller units Unit type First cost PV energy c ost PV maintenance cost PV replacement cost Life cycle cost Rank D X systems Wall mounted unit $ 1,220 $ 21,111 $ 6,799 $ 6,029 $ 35,158 5 Package rooftop $ 1,160 $ 21,111 $ 6, 799 $ 5,732 $ 34,802 5 Key Split system $ 1,050 $ 19,192 $ 3,824 $ 5,189 $ 29,255 4 $0 to $25,000 Water loop heat pump $ 900 $ 19,192 $ 5,099 $ 3,652 $ 28,843 4 $25,001 to $30,000 Geothermal heat pump $ 1,240 $ 16,633 $ 5,099 $ 3,627 $ 26,599 3 $30,001 or greater Chiller systems Air cooled chiller $ 460 $ 18,552 $ 395 $ 1,533 $ 20,940 2 Water cooled chiller $ 530 $ 9,596 $ 395 $ 1,766 $ 12,287 1 Table 416. Summary and ranking of the life cycle costs for the Air Distribution systems Unit t ype First c ost NPV replacement c ost Life cycle c ost Rank Key Air Distribution systems Constant volume $ $ $ 1 $0 to $1,000 VAV box $ 790 $ 1,290 $ 2,080 2 $1,001 to $2,000 Fan coil unit $ 1,360 $ 2,221 $ 3,581 3 $2,001 or greater

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61 T ab le 4 17. Space characteristics for typical designs of DX and Chiller systems. Unit type Typical size of unit (H x W x D) A ssociated equipment Placement of unit / equipment Required piping Ductwork / ceiling space Mechanical room / closet needed DX systems Wall Mounted Unit (1 ton) 48" x 32" x 15" N/A Mounted on wall No piping No d uctwork No Package rooftop (20 ton) 55" x 133" x 91" N/A On roof No piping Typical No Split systems (5 ton) Condensing unit : 45" x 37" x 34" AHU: 58" x 24" x 21" Condensing unit and AHU Outside condensing unit and indoor AHU Refrigerant piping between condensing unit and AHU Typical Yes W ater Loop Heat Pump (5 ton) Condensing unit : 27" x 59" x 29" AHU: 58" x 24" x 21" Boiler, cooling tower p ump Unit, boiler, and pump in mechanical room / cooling tower outside Piping from unit to boiler and cooling tower Typical Yes Geothermal Heat Pump (5 ton) Condensing unit : 27" x 59" x 29" AHU: 58" x 24" x 21" Pump Unit and pump in mechanical room Piping from ground to unit Typical Yes Chiller systems Air cooled chiller (150 ton) 100" x 95" x 88" Pumps, AHUS Chiller and pumps in outside service ar ea / AHUs in mechanical rooms throughout building Chilled water piping to central AHUS Typical Yes Water cooled chiller (150 ton) 75" x 170" 34" Cooling tower pumps AHUS Chiller & pumps in central mechanical room / outside cooling tower / AHUs in mech anical rooms throughout building Chilled water piping to cooling tower and central AHUS Typical Yes

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62 Table 418. Calculation of the amount of required s pace needed for DX and Chiller s ystems. Unit type Size of the unit Piping required Mechanical room sp ace required Outdoor space required Average Rank DX system s Wall mounted unit 1 1 1 1 1.00 1 Package rooftop 2 1 1 2 1.50 2 Key Split systems 2 2 2 2 2.00 3 1.00 Water loop heat pump 2 3 2 2 2.25 4 1.00 to 2.50 Geothermal heat pump 2 3 2 1 2.00 3 2.50 to 3.00 Chiller systems Air cooled chiller 3 3 2 3 2.75 5 Water cooled chiller 3 3 3 3 3.00 6

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63 Table 420. Space characteristics of typical Air Distribution systems System Associated e quipment Size of e quipment (H x W x D) Required p iping Equipment in ceiling s pace Air Distribution systems Constant volume N/ A N/ A No piping Ductwork only V AV VAV boxes 13" x 34" x 10" (250 cfm) No piping VAV boxes and ductwork Fan coil Fan coil units 16" x 36"x 31" (1,000 cfm) Chilled water pipin g to each fan coil Fancoil units, piping and ductwork Table 421. Calculation of required space for Air Distribution systems. System t ype Piping Amount of equipment in ceiling s pace Average Rank Key Air Distribution systems Constant volume 1 1 1.00 1 1.00 VAV 1 2 1.50 2 1.00 to 2.50 Fan coil units 3 2 2.50 3 2.75 to 3.00 Table 422. Ranking of the complexity of the DX and Chiller systems Unit type Components to install Points of maintenance Average Rank DX systems Wall mounted unit 1 1 1 .00 1 Package rooftop 1 1 1.00 1 Key Split system 2 1 1.50 2 1.00 to 2.00 Water loop heat pump 3 3 3.00 4 2.00 to 3.00 Geothermal heat pump 2 2 2.00 3 3.00 Chiller system s Air cooled chiller 3 3 3.00 4 Water cooled chiller 3 3 3.00 4 1: Little to none 2: Average 3: Excessive

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64 Each system complexity characteristic was rated on a scale from one to three with one being the least complex. Table 423 shows the calculation of the ranking of the complexity of the Air Distribution system s. Table 420 was used as a reference in the completion of this table. Each system complexity characteristic was rated on a scale from one to three with one being the least complex. Table 423. Ranking of the complexity of the Air Distribution systems Un it type Components to install Points of maintenance Average Rank Air Distribution systems Constant volume 1 1 1.00 1 Key VAV 2 2 2.00 2 1.00 to 2.00 Fan coil units 3 2 2.50 3 2.00 to 3.00 1: Little to none 2: Average 3: Excessive 3.00 Life o f the Unit Table 424 summarizes the sources that were examined in order to determine the service life of units. The Air Distribution systems were rated separately from the DX and Chiller systems but still follow the same key. It was found that unit life r anged from 15 years to 30 years. Any units with a life of 15 years up to 20 years were considered to be poor. Units with a service life of 20 years up to 25 years were considered to have an average service life. Units with a service life of 25 years or greater were deemed to have an above average service life. Noise Table 425 summarizes the potential sources of noise heard in the classroom. This table was used in the rating of the noise characteristics of the HVAC systems which are calculated in Table 426 Each noise characteristic was rated on a scale of one to three.

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65 Table 425. Potential sources of noise in classroom Unit type Equipment in classroom Equipment near classroom Other sources of noise in classroom DX systems Wall mounted unit Fan Compres sor and condenser on outside wall of classroom Vibration of building structure Package rooftop None None Rooftop rumble Split system None AHU in mechanical closet ; condensing unit outside None Water loop heat pump None AHU in mechanical closet None Geothermal heat pump None AHU in mechanical closet None Chiller systems Air cooled chiller None AHU in central mechanical room / closet None Water cooled chiller None AHU in central mechanical room / closet None Air Distribution systems Constant volum e Ductwork above ceiling None Air moving through ductwork VAV VAV boxes above ceiling (no fan) Potential placement of VAV above corridor Air moving through ductwork Fan c oil Units Fancoil above ceiling or in mechanical closet Potential placement of f a n c oil above corridor Air moving through ductwork It should be advised that these rankings do not guarantee that a system will fall within the required 35 dB sound level. It only highlights the potential of the system to generate noise in the classroom. The design professional must take measures to reduce system generated noise in the specific design of the system. Temperature Control Temperature control was only able to be determined for the Air Distribution systems. Table 427 shows the ranking of thes e systems ability to control temperature in the conditioned space.

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66 Table 424. Summary of sources examined in the determination of unit service life Unit type From literature review Contractor's estimate From ASHRAE table (2007) From Abramson et al. (20 05) Service life used in s tudy Rank DX systems Wall mounted u nit 9 2 16+ 15 N/A 15 4 Package rooftop 10 to 15 1 12 2 15 15 N/A 15 4 Split systems 12 2 12 to 15 15 N/A 15 4 Water loop heat pump 10 to 15 1 12 2 16 to 18 19 >24 24 2 Key Geotherm al heat pump N/A 18 19 >24 24 2 25 or greater Chiller systems Air cooled chiller (centrifugal) 25 to 30 1 10 to 15 20 N/A 20 3 20 25 Water cooled chiller (centrifugal) 25 to 30 1 15 to 20 20 >25 25 1 15 20 Air Distribution systems were ranked sepa rately from the DX and Chiller systems Air Distribution systems Constant Volume (ductwork) N/A N/A 30 N/A 5 0 1 VAV box 16 2 N/A 20 N/A 20 2 Fan coil unit N/A N/A 20 N/A 20 2 1 Colen (1990) ; 2 Ottaviano (1993)

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67 Table 426. Rating of noise c haracteristics for HVAC systems Unit t ype Sources of noise in c lassroom Sources of n oise near c lassroom Other sources of noise in c lassroom Average Ranking DX s ystems Wall mounted unit 3 3 3 3.00 3 Package rooftop 1 1 2 1.33 1 Split system 1 3 1 1.67 2 Key Water loop heat pump 1 2 1 1.33 1 1.00 to 1.50 Geothermal heat pump 1 2 1 1.33 1 1.50 to 2.00 Chiller systems Air cooled chiller 1 2 1 1.33 1 2.00 to 3.00 Water cooled chiller 1 2 1 1.33 1 Air Distribution systems were rated separately from the DX and Chiller s ystems Air Distribut ion systems Constant volume 1 1 2 1.33 1 VAV 1 1 2 1.33 1 Fan coil units 2 2 2 2.00 2 1: No noise from equipment 2: Possible source of n oise 3: Source of n oise

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68 Table 427. Ranking of t he Air Distribution systems ability to control temperature of the space Unit t ype Control t ype Rank Air Distribution systems Constant v olume On/Off 2 VAV Modulating 1 Fan coil units Modulating 1 The constant volume air method is considered to be t he standard method of air distribution. It delivers air to the space by cycling the HVAC unit on or off as needed. Both the VAV and Fan Coil methods of air distribution use modulating controls to regulate the temperature of the conditioned space. This allows for better control of the temperature of the space.

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69 CHAPTER 5 RESULTS The following are the completed decision matrices based on the calculations in the previous chapter. DX and Chiller Systems Table 51 gives that completed decision matrix for the DX a nd Chiller systems. This table is a summary of all the color and numerical rankings for both the cost and design criteria. The values obtained for the costs of these systems in this general study did not have a large variation. However, three different ra nges in costs were seen. These ranges are represented by the color scale. Due to the accuracy of the costs that were able to be obtained during this study, the color scale is the more accurate of the two scales used in the matrix. It allows the user to qui ckly identify which range of costs the system falls within. The numerical ranking of the matrix would be more effective for use with a specific building design versus a general study such as this one. Air Distribution Systems Table 52 gives the completed decision matrix for the Air Distribution systems. This table is a summary of all the color and numerical rankings for both the cost and design criteria. The variation in costs was not as large for these s ystems as with the DX and Chiller systems. However, the color scale again allows the user to quickly identify which range of costs the system falls within.

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70 Table 51. Completed decision matrix for DX and Chiller s ystems Costs Other Unit t ype First c ost Energy c ost Maintenance c ost Replacement c ost LCC Required s pace Complexity Life of u nit Noise Wall mounted unit 6 5 4 6 5 1 1 4 3 Package rooftop 5 5 4 5 5 2 1 4 1 Split system 4 4 2 4 4 3 2 4 2 Water loop heat pump 3 4 3 3 4 4 4 2 1 Geothermal heat pump 6 2 3 3 3 3 3 2 1 Air cooled chiller 1 3 1 1 2 5 4 3 1 Water cooled chiller 2 1 1 2 1 6 4 1 1 Table 52. Completed decision matrix for the Air Distribution systems Costs Other Unit type First cost Replacement cost L CC Required space Complexity Life of unit Noise Temperature control Constant volume 1 1 1 1 1 1 1 2 VAV 2 2 2 2 2 2 1 1 Fan coil units 3 3 3 3 3 2 2 1

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71 CHAPTER 6 CONCLUSIONS From the research conducted it was found that a general life cycle cost analysis of HVAC systems was not possible to perform. Because each system is unique to the design of a building, only the approximate costs for the HVAC units were able to be obtained for this study. Even then costs varied based upon the size and placement of the unit. Exact cost data was found to be difficult to obtain as the HVAC indust ry does not track general cost information. Pricing is done for a specific system according to its design specifications. The decision matrix created proved to be a valuable tool in the selection of an HVAC system for Florida public schools. It effectively presented the HVAC unit performance in both the cost and design criteria categories so that the units may be compared The color scale allows the user to quickly identify the units that fall within the desired performance levels. T he numerical scale allow s the user to determine the best choice within these performance levels. However, the numerical ranking would be more effective for use with a specific building design versus a general study such as this one. The proposed decision matrix could be adapted t o meet the specific needs of individual counties in Florida

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72 CHAPTER 7 RECOMMENDATIONS This study was based on a broad scope. For future studies it would be effective to narrow the scope to individual counties. Obtaining the costs of HVAC systems that are constructed in a particular county would provide a more accurate analysis of the costs for a specific region. The matrix developed in this study could be further developed or changed to accurately reflect the specific needs of the school district being an alyzed. One of the difficulties of this study was finding accurate cost data for individual system components and systems as a whole. Further research could focus on collecting a larger source of quotes of HVAC units. This would provide a more accurate es timate of the cost per ton of a unit. The first costs of entire HVAC systems could also be analyzed. A life cycle cost analysis of an entire HVAC system would more accurately reflect the costs that a school district would incur. Median service life of HVA C systems could also be analyzed. The median service life used in this study was based off of ASHRAEs recommendations. However, this service life was calculated using the time of replacement for units all over the United States. The replacement of units i n other climatic regions could be different than those for the State of Florida. A database could be created to track the year at which equipment is installed in schools and the year when it is replaced. The creation of such a database would better help the state estimate life cycle costs

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73 APPENDIX A INSTALLATION COSTS OF FLORIDA SCHOOLS Table A 1 lists the costs of the major HVAC equipment that was put installed in two schools in Pasco County, Florida. Both schools used the same HVAC system design of an air cooled chiller with VAV units for air distribution. The materials for these systems were purchased through the Direct Purchase Program. This allows the State to purchase materials tax free. Table A 2 gives a summary of the total costs of the HVAC syste ms that were installed in the schools. It calculates the cost per ton of the materials and the installed cost per ton. It also shows the percentage of material costs to the total mechanical system cost and the percentage of the mechanical system costs to t he total school cost. Table A 1. HVAC system component costs for two elementary schools in Pasco County Florida System component costs Cost Tons Cost per ton Watergrass Elementary (LEED Gold Certified) 2A air cooled chillers $ 136,027.00 300 $ 453. 42 AHU, VAVs, blower coils $ 71,922.42 2 DX mini splits $ 11,355.00 Ductwork $ 5,789.34 Total air distribution $ 96,387.00 Gulf Trace Elementary (LEED Silver Certified ) 2 Air cooled chillers $ 129,115. 24 300 $ 430.38 AHU, VAVs, blower coils $ 72,340.40 Ductwork $ 4,920.00 Total air distribution $ 80,590.00

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74 Table A 2. Total c osts for the installation of an air cooled chiller system in Pasco County elementary schools Total costs Cost per ton Watergrass Elementary Total material cost $ 486,521.04 $ 1,621.74 Total mechanical contractor amount $ 1,191,478.96 $ 3,971.60 Total cos t for HVAC system $ 1,678,000.00 $ 5,593.33 Total construction co st of school $ 11,322,720.00 Percentage of material cost to total mechanical cost 41% Percentage of mechanical system cost to total construction cost 15% Gulf Trace Elementary Total material cost $ 357,997.16 $ 1,193.32 Total mechanical contractor amount $ 1,131,202.84 $ 3,770.68 Total cos t for HVAC system $ 1,489,200.00 $ 4,964.00 Total construction cost of school $ 11,820,540.91 Percentage of material cost to total mechanical cost 32% P ercentage of mechanical cost to total construction cost 13%

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75 APPENDIX B PRESENT VALUE CALCUL ATIONS Energy Costs Table B 1 gives a summary of the annual unit energy costs that were used in the calculation of the total present value of the energy cost. It also gives the inflation rate and the discount rate. Table B 2 shows the calculation of the total present value of the annual energy costs for the HVAC units over the 50 year building life. Table B 1. Summary of costs and rates used in the calculation of the total present value of unit energy costs Unit HVAC unit Annual energy cost 1.0 Wall mounted unit $ 330 2.0 Package rooftop $ 330 3.0 Split systems $ 300 4.0 Water loop heat pump $ 300 5.0 Geothermal heat pu mp $ 260 6.0 Air cooled chiller $ 290 7.0 Water cooled chiller $ 150 Inflation rate 4.0% Discount rate 3.0% Table B 2 Calculation of total present v alue of unit energy cost Year 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0 $ 330 $ 330 $ 300 $ 300 $ 260 $ 290 $ 150 1 $ 333 $ 333 $ 303 $ 303 $ 263 $ 293 $ 151 2 $ 336 $ 336 $ 306 $ 306 $ 265 $ 296 $ 153 3 $ 340 $ 340 $ 309 $ 309 $ 268 $ 299 $ 154 4 $ 343 $ 343 $ 312 $ 312 $ 270 $ 30 1 $ 156 5 $ 346 $ 346 $ 315 $ 315 $ 273 $ 304 $ 157 6 $ 350 $ 350 $ 318 $ 318 $ 276 $ 307 $ 159 7 $ 353 $ 353 $ 321 $ 32 1 $ 278 $ 310 $ 160 8 $ 357 $ 357 $ 324 $ 324 $ 281 $ 313 $ 162 9 $ 360 $ 360 $ 327 $ 327 $ 284 $ 316 $ 164 10 $ 363 $ 3 63 $ 330 $ 330 $ 286 $ 319 $ 165 11 $ 367 $ 367 $ 334 $ 334 $ 289 $ 323 $ 167 12 $ 371 $ 371 $ 337 $ 337 $ 292 $ 326 $ 16 8

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76 Table B 2. Continued Year 1.0 2.0 3.0 4.0 5.0 6.0 7.0 13 $ 374 $ 374 $ 340 $ 340 $ 295 $ 329 $ 170 14 $ 378 $ 378 $ 343 $ 343 $ 298 $ 332 $ 172 15 $ 381 $ 381 $ 347 $ 347 $ 301 $ 335 $ 173 16 $ 385 $ 385 $ 350 $ 350 $ 303 $ 338 $ 175 17 $ 389 $ 389 $ 354 $ 354 $ 306 $ 342 $ 177 18 $ 393 $ 393 $ 357 $ 357 $ 309 $ 345 $ 178 19 $ 396 $ 396 $ 360 $ 360 $ 312 $ 348 $ 180 20 $ 400 $ 400 $ 364 $ 364 $ 315 $ 352 $ 182 21 $ 404 $ 404 $ 367 $ 367 $ 318 $ 355 $ 184 22 $ 408 $ 408 $ 371 $ 371 $ 322 $ 359 $ 186 23 $ 412 $ 412 $ 375 $ 375 $ 325 $ 362 $ 187 24 $ 416 $ 416 $ 378 $ 378 $ 328 $ 366 $ 189 25 $ 420 $ 420 $ 382 $ 382 $ 331 $ 369 $ 191 26 $ 424 $ 424 $ 386 $ 386 $ 334 $ 373 $ 193 27 $ 428 $ 428 $ 389 $ 389 $ 337 $ 376 $ 195 28 $ 433 $ 433 $ 393 $ 393 $ 341 $ 380 $ 197 29 $ 437 $ 437 $ 397 $ 397 $ 344 $ 384 $ 199 30 $ 441 $ 441 $ 401 $ 401 $ 347 $ 388 $ 200 31 $ 445 $ 445 $ 405 $ 405 $ 351 $ 391 $ 202 32 $ 450 $ 450 $ 409 $ 409 $ 354 $ 395 $ 204 33 $ 454 $ 454 $ 413 $ 413 $ 358 $ 399 $ 206 34 $ 458 $ 458 $ 417 $ 417 $ 361 $ 403 $ 208 35 $ 463 $ 463 $ 421 $ 421 $ 365 $ 407 $ 210 36 $ 467 $ 467 $ 425 $ 425 $ 368 $ 411 $ 212 37 $ 472 $ 472 $ 429 $ 42 9 $ 372 $ 415 $ 214 38 $ 476 $ 476 $ 433 $ 433 $ 375 $ 419 $ 217 39 $ 481 $ 481 $ 437 $ 437 $ 379 $ 423 $ 219 40 $ 486 $ 486 $ 442 $ 442 $ 383 $ 427 $ 221 41 $ 490 $ 490 $ 446 $ 446 $ 386 $ 431 $ 223 42 $ 495 $ 495 $ 450 $ 450 $ 390 $ 435 $ 225 43 $ 500 $ 500 $ 455 $ 455 $ 394 $ 439 $ 227 44 $ 505 $ 505 $ 459 $ 459 $ 398 $ 444 $ 229 45 $ 510 $ 510 $ 463 $ 463 $ 402 $ 448 $ 232 46 $ 515 $ 515 $ 468 $ 468 $ 406 $ 452 $ 234 47 $ 520 $ 520 $ 472 $ 472 $ 409 $ 457 $ 236 48 $ 525 $ 525 $ 477 $ 477 $ 413 $ 461 $ 239 49 $ 530 $ 530 $ 482 $ 482 $ 417 $ 466 $ 241 Total PV $ 21, 111 $ 21,111 $ 19,192 $ 19,192 $ 16,633 $ 18,552 $ 9,596

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77 Maintenance Costs Table B 3 gives a summary of the annual unit maintenance costs and that were used in the calculation of the total present value of cost. Table B 4 shows the calculatio n of the tot al present value of the annual maintenance costs for the HVAC units over the 50 year building life. Table B 3. Summary of costs and rates used in the calculation of the total present value of unit maintenance costs Unit HVAC unit Annual mainten ance cost per ton 1.0 Wall mounted unit $ 160 2.0 Package rooftop $ 160 3.0 Split systems $ 90 4.0 Water loop heat pump $ 120 5.0 Geothermal heat pump $ 120 6.0 Air cooled chiller $ 9.30 7.0 Water cooled chiller $ 9.30 Inflation rate 2.00% Discount rate 2.70% Table B 4. Calculation of the total present value of unit maintenance cost Year 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0 $ 160 $ 160 $ 90 $ 120 $ 120 $ 9 $ 9 1 $ 159 $ 159 $ 89 $ 119 $ 119 $ 9 $ 9 2 $ 158 $ 158 $ 89 $ 118 $ 118 $ 9 $ 9 3 $ 157 $ 157 $ 88 $ 118 $ 118 $ 9 $ 9 4 $ 156 $ 156 $ 88 $ 117 $ 117 $ 9 $ 9 5 $ 155 $ 155 $ 87 $ 116 $ 116 $ 9 $ 9 6 $ 154 $ 154 $ 86 $ 115 $ 115 $ 9 $ 9 7 $ 153 $ 153 $ 86 $ 114 $ 114 $ 9 $ 9 8 $ 151 $ 151 $ 85 $ 114 $ 114 $ 9 $ 9 9 $ 150 $ 150 $ 85 $ 113 $ 113 $ 9 $ 9 10 $ 149 $ 149 $ 84 $ 112 $ 112 $ 9 $ 9 11 $ 148 $ 148 $ 83 $ 111 $ 111 $ 9 $ 9 12 $ 147 $ 147 $ 83 $ 111 $ 111 $ 9 $ 9 13 $ 146 $ 146 $ 82 $ 110 $ 110 $ 9 $ 9

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78 Table B 4. Continued Year 1.0 2.0 3.0 4.0 5.0 6.0 7.0 14 $ 145 $ 145 $ 82 $ 109 $ 109 $ 8 $ 8 15 $ 144 $ 144 $ 81 $ 108 $ 108 $ 8 $ 8 16 $ 143 $ 143 $ 81 $ 108 $ 108 $ 8 $ 8 17 $ 142 $ 142 $ 80 $ 107 $ 107 $ 8 $ 8 18 $ 141 $ 141 $ 80 $ 106 $ 106 $ 8 $ 8 19 $ 141 $ 141 $ 79 $ 105 $ 105 $ 8 $ 8 20 $ 140 $ 140 $ 78 $ 105 $ 105 $ 8 $ 8 21 $ 139 $ 139 $ 78 $ 104 $ 104 $ 8 $ 8 22 $ 138 $ 138 $ 77 $ 103 $ 103 $ 8 $ 8 23 $ 137 $ 137 $ 77 $ 103 $ 103 $ 8 $ 8 24 $ 136 $ 136 $ 76 $ 102 $ 102 $ 8 $ 8 25 $ 135 $ 135 $ 76 $ 101 $ 101 $ 8 $ 8 26 $ 134 $ 134 $ 75 $ 100 $ 100 $ 8 $ 8 27 $ 133 $ 133 $ 75 $ 100 $ 100 $ 8 $ 8 28 $ 132 $ 132 $ 74 $ 99 $ 99 $ 8 $ 8 29 $ 131 $ 131 $ 74 $ 98 $ 98 $ 8 $ 8 30 $ 130 $ 130 $ 73 $ 98 $ 98 $ 8 $ 8 31 $ 129 $ 129 $ 73 $ 97 $ 97 $ 8 $ 8 32 $ 129 $ 129 $ 72 $ 96 $ 96 $ 7 $ 7 33 $ 128 $ 128 $ 72 $ 96 $ 96 $ 7 $ 7 34 $ 127 $ 127 $ 71 $ 95 $ 95 $ 7 $ 7 35 $ 126 $ 126 $ 71 $ 94 $ 94 $ 7 $ 7 36 $ 125 $ 125 $ 70 $ 94 $ 94 $ 7 $ 7 37 $ 124 $ 124 $ 70 $ 93 $ 93 $ 7 $ 7 38 $ 123 $ 123 $ 69 $ 93 $ 93 $ 7 $ 7 39 $ 123 $ 123 $ 69 $ 92 $ 92 $ 7 $ 7 40 $ 122 $ 122 $ 68 $ 91 $ 91 $ 7 $ 7 41 $ 121 $ 121 $ 68 $ 91 $ 91 $ 7 $ 7 42 $ 120 $ 120 $ 68 $ 90 $ 90 $ 7 $ 7 43 $ 119 $ 119 $ 67 $ 89 $ 89 $ 7 $ 7 44 $ 118 $ 118 $ 67 $ 89 $ 89 $ 7 $ 7 45 $ 118 $ 118 $ 66 $ 88 $ 88 $ 7 $ 7 46 $ 117 $ 117 $ 66 $ 88 $ 88 $ 7 $ 7 47 $ 116 $ 116 $ 65 $ 87 $ 87 $ 7 $ 7 48 $ 115 $ 115 $ 65 $ 86 $ 86 $ 7 $ 7 49 $ 114 $ 114 $ 64 $ 86 $ 86 $ 7 $ 7 Total PV $ 6,799 $ 6,799 $ 3,824 $ 5,099 $ 5,099 $ 395 $ 395

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79 Replacement Co sts Table B 5 gives a summary of the annual costs to replace miscellaneous unit equipment. It also gives the inflation and discount rates that were used in the calculation of the total present value of these cost s. Table B 5. Summary of costs and rates us ed in the calculation of the total present value of miscellaneous unit replacement costs Unit HVAC unit Annual misc ellaneous replacement cost 1.0 Wall mounted unit $ 73 2.0 Package rooftop $ 70 3.0 Split systems $ 63 4.0 Water loop heat pump $ 54 5.0 Geothermal heat pump $ 74 6.0 Air cooled chiller $ 28 7.0 Water cooled chiller $ 32 Inflation rate 2.00% Discount rate 2.70% Tabl e B 6 shows the calculation of the total present value of the miscellaneous equipment replacement costs for the HVAC units over the 50 year building life. The replac ement cost for the first year after installation (year zero) has been neglected in these ca lculations as the manufacturer or mechanical contractor will provide a one year warranty on the parts and labor of any replacements. Table B 6. Calculation of the total present value of miscellaneous unit replacement cost s Year 1.0 2.0 3.0 4.0 5.0 6.0 7.0 1 $ 73 $ 69 $ 63 $ 54 $ 74 $ 27 $ 32 2 $ 72 $ 69 $ 62 $ 53 $ 73 $ 27 $ 31 3 $ 72 $ 68 $ 62 $ 53 $ 73 $ 27 $ 31 4 $ 71 $ 68 $ 61 $ 53 $ 72 $ 27 $ 31 5 $ 71 $ 67 $ 61 $ 52 $ 72 $ 27 $ 31 6 $ 70 $ 67 $ 60 $ 52 $ 71 $ 26 $ 31

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80 Table B 6. Continued Year 1.0 2.0 3.0 4.0 5.0 6.0 7.0 7 $ 70 $ 66 $ 60 $ 51 $ 71 $ 26 $ 30 8 $ 69 $ 66 $ 60 $ 51 $ 70 $ 26 $ 30 9 $ 69 $ 65 $ 59 $ 51 $ 70 $ 26 $ 30 10 $ 68 $ 65 $ 59 $ 50 $ 69 $ 26 $ 30 11 $ 68 $ 65 $ 58 $ 50 $ 69 $ 26 $ 29 12 $ 67 $ 64 $ 58 $ 50 $ 69 $ 25 $ 29 13 $ 67 $ 64 $ 58 $ 49 $ 68 $ 25 $ 29 14 $ 67 $ 63 $ 57 $ 49 $ 68 $ 25 $ 29 15 $ 66 $ 63 $ 57 $ 49 $ 67 $ 25 $ 29 16 $ 66 $ 62 $ 56 $ 48 $ 67 $ 25 $ 29 17 $ 65 $ 62 $ 56 $ 48 $ 66 $ 25 $ 28 18 $ 65 $ 62 $ 56 $ 48 $ 66 $ 24 $ 28 19 $ 64 $ 61 $ 55 $ 47 $ 65 $ 24 $ 28 20 $ 64 $ 61 $ 55 $ 47 $ 65 $ 24 $ 28 21 $ 63 $ 60 $ 55 $ 47 $ 64 $ 24 $ 28 22 $ 63 $ 60 $ 54 $ 46 $ 64 $ 24 $ 27 23 $ 63 $ 59 $ 54 $ 46 $ 64 $ 24 $ 27 24 $ 62 $ 59 $ 53 $ 46 $ 63 $ 23 $ 27 25 $ 62 $ 59 $ 53 $ 46 $ 63 $ 23 $ 27 26 $ 61 $ 58 $ 53 $ 45 $ 62 $ 23 $ 27 27 $ 61 $ 58 $ 52 $ 45 $ 62 $ 23 $ 26 28 $ 60 $ 57 $ 52 $ 45 $ 61 $ 23 $ 26 29 $ 60 $ 57 $ 52 $ 44 $ 61 $ 23 $ 26 30 $ 60 $ 57 $ 51 $ 44 $ 61 $ 22 $ 26 31 $ 59 $ 56 $ 51 $ 44 $ 60 $ 22 $ 26 32 $ 59 $ 56 $ 51 $ 43 $ 60 $ 22 $ 26 33 $ 58 $ 56 $ 50 $ 43 $ 59 $ 22 $ 25 34 $ 58 $ 55 $ 50 $ 43 $ 59 $ 22 $ 25 35 $ 58 $ 55 $ 50 $ 43 $ 59 $ 22 $ 25 36 $ 57 $ 54 $ 49 $ 42 $ 58 $ 22 $ 25 37 $ 57 $ 54 $ 49 $ 42 $ 58 $ 21 $ 25 38 $ 56 $ 54 $ 49 $ 42 $ 57 $ 21 $ 25 39 $ 56 $ 53 $ 48 $ 41 $ 57 $ 21 $ 24 40 $ 56 $ 53 $ 48 $ 41 $ 57 $ 21 $ 24 41 $ 55 $ 53 $ 48 $ 41 $ 56 $ 21 $ 24 42 $ 55 $ 52 $ 47 $ 41 $ 56 $ 21 $ 24 43 $ 55 $ 52 $ 47 $ 40 $ 55 $ 21 $ 24 44 $ 54 $ 52 $ 47 $ 40 $ 55 $ 20 $ 24 45 $ 54 $ 51 $ 46 $ 40 $ 55 $ 20 $ 23

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81 Table B 6. Continued Year 1.0 2.0 3.0 4.0 5.0 6.0 7.0 46 $ 53 $ 51 $ 46 $ 39 $ 54 $ 20 $ 23 47 $ 53 $ 50 $ 46 $ 39 $ 54 $ 20 $ 23 48 $ 53 $ 50 $ 45 $ 39 $ 54 $ 20 $ 23 49 $ 52 $ 50 $ 45 $ 39 $ 53 $ 20 $ 23 Total PV $ 3,037 $ 2,888 $ 2,614 $ 2,241 $ 3,087 $ 1,145 $ 1,319

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82 LIST OF REFERENCES Abramson, B., Herman, D., and Wong, L. (2005). Interactive Webbased owning and operating cost database (TRP 1237) ASHRAE Research Project, Final Report. Akalin, M.T. (1978). Equipment life and maintenance cost survey (RP 186). ASHRAE Transactions 84(2), 94 106. American Society of Heating, Refrigerating and Air Conditions Engineers (2010). ASHRAE: HVAC Maintenance Cost Database., < http://xp20.ashrae.org/publicdatabase/maintenance.asp > (Feb. 27, 2010). American Society of Heating,Refrigerating and Air Conditioning Engineers and Knovel. (2008). 2008 ASHRAE handbook [electronic resource] : heating, ventilating, and air conditioning systems and equipment. ASHRAE, Atlanta, Ga. American Society of Heating,Refrigerating and Air Conditioning Engineers, and Knovel. (2007). 2007 ASHRAE handbook [electronic resource] : heating, ventilating, and ai r conditioning applications. ASHRAE, Atlanta, Georgia. Colen, H. R. (1990). HVAC systems evaluation. R.S. Means Company, Kingston, MA. Elovitz, D. M. (2002). "Selecting the right HVAC system." ASHRAE J., 44(1), 2430. Fischer, J. C., and Bayer, C. W. (2 003). "Report Card on Humidity Control." ASHRAE J., 45(5), 302, 34, 36 9. Florida Department of Education (2003). Instructions for Life Cycle Cost Analysis of School HVAC Systems < http://www.fldoe.org/edfacil/pdf/lcca.pdf > (Feb. 27, 2010) Florida Depar tment of Education (1999). Life Cycle Cost Guidelines for Materials and Building Systems for Floridas Public Educational Facilities Fuller, S. K., and Peterson, S. R. (1996). "Life Cycle Costing Manual for the Federal Energy Management Program." U.S. Go vernment Printing Office, Washington, DC Hiller, C. C. (2000). "Determining equipment service life." ASHRAE J., 42(8), 4854. Janis, R. R., and Tao, W. K. Y. (2009). "Mechanical and Electrical Systems in Buildings." Prentice Hall, Upper Saddle River, NJ 15 16. Oppenheim, P. (1992). "A Decision Matrix for Selection of Climate Control Equipment." National Association of Industrial Technology, 8(4), 42 46. Ottaviano, V. B. (1993). National Mechanical Estimator The Fairmont Press, Lilburn, GA.

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83 RS Means ( 2010). CostWorks., < http://www.meanscostworks.com/ > (Feb. 27 2010). Siebein, G. W., and Lilkendey, R. M. (2004). "Acoustical Case Studies of HVAC Systems in Schools." ASHRAE J., 46(5), 356, 38 9, 41 2, 44, 467. The Trane Company (1991). Systems Manual US Department of Energy (2009). Purchasing Specifications f or Energy Efficient Products., < http://www1.eere.energy.gov/femp/technologies/eep_purchasingspecs.html > ( Feb. 27 2010).

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84 BIOGRAPHICAL SKETCH Kelly McLaughlin was born and raised in West Palm Beach, Florida. She is the daughter of Jack and Nadean McLaughlin and has a younger brother Stephen. She attended the University of Florida where she obtained her Bachel or of Science in Mechanical Engineering in 2008. She then pursued a Master of Science in Building Construction. Upon graduation Kelly plans to work for Walt Disney World as a construction project manager.