LS j'VoHj'o If. ECONOMIC POTENTIAL OF ENERGY CONSERVATION IN A FIVE STAR HOTEL By . ABDUL MAJEED MUZATHIK BSc.Eng. (Hons.) THE UNIVERSITY OF MORATUWA, SRI LANKA. Thesis submitted to the Department of Mechanical Engineering of the University of Moratuwa in partial fulfillment of the requirements for the Degree of Master of Engineering in Energy Technology. University of M o r a t u w a 79623 DEPARTMENT OF MECHANICAL ENGINEERING FACULTY OF ENGINEERING UNIVERSITY OF MORATUWA SRI LANKA October 2003 1 ^ 6 < 2 3 7 9 6 2 3 DECLARATION I hereby declare that to the best of my knowledge, this submission is my own work and it contains neither direct material previously published nor written by another person or material, which to substantial extent, has been accepted for the award of any other academic qualification of a university or other institute of higher learning except where acknowledgment is made in the text. October 2003 i ABSTRACT Economic potential of energy conservation in a five star hotel was established. The selected site was the Hotel Lanka Oberoi, Colombo. The electrical energy demand and the thermal energy demand of the hotel were assessed using the results of an energy audit carried out in the Hotel by the Energy Conservation Fund (ECF). It was found that there are several energy conservation opportunities (ECOs) for the Hotel. Economic analysis was carried out for the six ECOs of VAV Systems, Low-e Glass Systems, Daylighting Control Systems, Energy Efficient Lighting Systems, Indoor Temperature Set Up and Thermal Energy Storage Systems. It showed that all the six ECOs are feasible with favorable economic parameters. Nevertheless there are merits and demerits among each of these ECOs and these were discussed with reference to each ECOs. Among the ECOs, VAV Systems and Energy Efficient Lighting Systems have the most favorable economic parameters with a payback period of 0.6 years and 0.2 years respectively. II TABLE OF CONTENTS ITEM PAGE DECLARATION I ABSTRACT II TABLE OF CONTENTS III LIST OF TABLES VIII LIST OF FIGURES XI ABBREVIATIONS XIII ACKNOWLEDGEMENT XIV 1.0 RESEARCH PROBLEM BEING ANALYZED 1.1 Background 1 1.2 Energy Use in Sri-Lanka 3 1.3 Energy used in buildings and Industries 6 1.4 Introduction to Energy Conservation 7 1.5 Research Problem at the Scene 11 1.6 Objective of the Study 12 1.7 Rational and Justification 13 2.0 LITERATURE SURVEY ON BUILDING ENERGY EFFICIENCY AND CONSERVATION 2.1 Energy Audits 14 2.1.1 Walk - Through Audits 14 2.1.2 Utility Cost Analysis 14 2.1.3 Standard Energy Audits 16 2.1.4 Detailed Energy Audits 16 in 2.1.5 General Procedure for a Detailed Energy Audit 17 2.1.5.1 Building and Utility Data Analysis 18 2.1.5.2 Walk-through Survey 19 2.1.5.3 Baseline for Building Energy Use 19 2.1.5.4 Evaluation of Energy Savings Measures 20 2.1.6 Common Energy Conservation Measures 23 2.1.6.1 Building Envelope 23 2.1.6.2 Electrical Systems 26 2.1.6.3 HVAC Systems 31 2.1.6.4 Energy Management Controls 3 5 2.1.6.5 Indoor Water Management 36 2.1.6.6 New Technologies 37 2.2 Energy Analysis Tools 43 2.2.1 Introduction 43 2.2.2 Ratio-Based Methods 45 2.2.2.1 Types of Ratios 47 2.2.3 Inverse Modeling Methods 49 2.2.3.1 Steady-State Inverse Models 50 2.2.3.2 Dynamic model 52 2.2.4 Forward modeling methods 53 2.2.4.1 Steady-state methods 53 2.2.4.2 Degree Day Methods 53 2.2.4.3 Bin Methods 54 2.2.5 Dynamic methods (Computer Simulation) 55 2.3 Method for Estimating Energy Savings 59 2.3.1 General Procedure 60 2.3.2 Energy Savings Estimation Models 62 2.3.2.1 Simplified Engineering Methods 62 2.3.2.2 Regression Analysis Models 62 IV 2.3.2.3 Dynamic Models 65 2.3.2.4 Computer Simulation Models 66 2.4 Economic Evaluation Methods to Select Alternatives 69 2.4.1 Net Present Worth 69 2.4.2 Rate of return 70 2.4.3 Benefit-Cost Ratio 71 2.4.4 Payback Period 71 2.4.5 Internal Rate of Return 72 2.4.6 Life-Cycle Cost Analysis Method 73 2.4.7 General Procedure for Economic Evaluation 74 ENERGY SITUATION OF THE HOTEL LANKA OBEROI 3.1 Introduction 77 3.2 Construction Details 78 3.3 Electrical System 81 3.4 Thermal System 82 3.5 Air Conditioning System 82 3.6 Existing Energy Balance 82 3.6.1 Annual Energy Balance Year 2000 84 3.6.2 Annual Energy Balance year 2001 85 3.7 Electricity Demand profile 87 3.8 Tariff System 88 3.9 Lighting 90 3.10 Pumping Stations 91 3.11 Laundry Equipment 91 3.12 Kitchen/Bakery Equipment 91 < 4.0 ENERGY AND ECONOMIC ANALYSIS OF CONSERVATION OPTIONS IN THE HOTEL - USING DOE2 4.1 Methodology 92 4.2 Simulation Model 92 4.3 The Flowchart of Visual DOE 95 4.4 Input Information for Visual DOE 96 4.5 Weather Input Data 97 4.6 Economic Parameters 98 4.7 Simplifications 99 4.8 Calibration 99 4.9 Calibration Result 101 4.10 Energy Conservation Opportunities 103 4.10.1 CAV Systems Replaced by VAV Systems 104 4.10.2 Clear Glass Replaced by Low-e Glass Systems 105 4.10.3 Daylighting Control Systems 105 4.10.4 Energy Efficient Lighting Systems 105 4.10.5 Indoor Temperature Set Up 106 4.10.6 Thermal Energy Storage (TES) Systems 106 4.11 Analysis of Selected ECOs by Visual DOE 107 4.12 Economic Analysis of ECOs 111 4.12.1 Investment Cost Estimation 111 4.12.2 Payback-Period Calculation 112 4.12.3 Calculation for Cost of Conserved Energy 113 4.12.4 IRR Calculation 114 RESULTS AND DISCUSSION 117 CONCLUSIONS 124 VI « 7.0 REFERENCES: 127 APPENDIX APPENDIX A: Data related to Hotel Lanka Oberoi 130 APPENDIX B Input Information for Visual DOE 135 APPENDIX C Detail Calculations 140 APPENDIX D Visual DOE Outputs 150 APPENDIX E Sample Visual DOE Printed Results 163 VII LIST OF TABLE CHAPTER 1 Table 1.1: Energy consumption by region Table 1.2: Energy consumption by energy sources for commercial source attributed to commercial and residential buildings in Sri Lanka. Table 1.3: Energy Intensity by Principal Buildings Activity in kWh/m . CHAPTER 2 Table 2.1: Energy Audit Summaries for Residential & Commercial Buildings Table 2.2: Typical efficiencies of Motors Table 2.3: Usage characteristics of water-using fixtures Table 2.4: Energy Ratio (Energy Intensity) by Principal building activity in kWh/m2 CHAPTER 3 Table 3.1: Building Construction Materials Table 3.2: Energy Sources for year 2000 and 2001. Table 3.3: Unit cost comparison of the energy source. Table 3.4: The Electrical Tariff System. Table 3.5: Maximum and Minimum kWh of Transformers Table 3.6: Lamp Population of the Hotel. VIII CHAPTER 4 Table 4.1: Monthly Electricity Usage (kWh) by Visual DOE Table 4.2: Electrical Use Summary for Base-Case and Six ECOs Table 4.3: Cumulative Electrical Saving (kWh) of ECOs, Compared with Base- Case, negative savings represent increases Table 4.4: Annual Electrical Energy Savings Compared with Base-Case Table 4.5: Investment cost summary of ECOs. Table4.6: Economic Analysis Summary of six ECOs APPENDIX A Table Al: Chiller Details. Table A2: Cooling Tower Details. Table A3: Water Consumption for year 2000 and 2001. Table A4: Conversion Factor Table A5: Occupancy Percentage for year 2000 and 2001. Table A6: Condenser Water Pumps. Table A7: Chilled Water Pumps. Table A8: Chilled Water Booster Pumps. APPENDIX D Electrical End-use Totals (kWh) Incremental Electrical Savings (kWh) Cumulative Electrical Savings (kWh) Energy Cost Summary ($/y) Total Energy Costs ($/y) Incremental Energy Savings ($/y) Cumulative Energy Savings ($/y) Monthly Electrical Usage (kWh) Monthly Electrical Power (kW) LIST OF FIGURES CHAPTER 1 Figure 1.1: Energy Supply by Source (2000) Figure 1.2: Electricity Consumption by Sectors. Figure 1.3: Per Capita Energy Consumption / Population Growth Ratio in Sri Lanka CHAPTER 2 Figure 2.1: Basic approach of a typical forward energy analysis model Figure 2.2: Basic approach of a typical inverse energy analysis model Figure 2.3: Flow chart of complete building model Figure 2.4: Daily variation of building energy consumption Figure 2.5: Typical calibration procedure for building energy simulation models CHAPTER 3 Figure 3.1: A typical floor of stage I Figure 3.2: A typical floor of stage II & III Figure 3.3: A typical floor of front office Figure 3.4: A typical floor of the hotel Figure 3.5: Energy share by source 2000 Figure 3.6: Energy cost share by source 2000 Figure 3.7: Energy share by source 2001 Figure 3.8: Energy cost share by source 2001 Figure 3.9: Comparison of unit cost by source. Figure3.10: Electricity Demand Profile. XI CHAPTER4 Figure 4.1: Building zoning configuration for Visual DOE computer simulation Figure 4.2 (a): Average monthly dry & wet bulb temperature data for Colombo Figure 4.2 (b): Average monthly solar radiation for Colombo Figure 4.3: Perspective view of Visual DOE model for the Hotel Lanka Oberoi Figure 4.4: Plan view of Visual DOE model for the Hotel Lanka Oberoi Figure 4.5: Calibration results of the monthly electricity predictions of Visual DOE model with actual billing electrical energy consumption in year 2000 for Hotel Lanka Oberoi Figure 4.6: Percentage of electricity end-uses based on the calibrated Visual DOE model of Hotel Lanka Oberoi APPENDIX D Visual DOE Outputs Electrical energy comparison between billing history and ECOs Perspective views of Visual DOE model for the Hotel Lanka Oberoi XII ABBREVIATIONS (Used in the thesis) AC Air Conditioning AHU Air Handling Unit ASD Adjustable Speed Drives ASHRAE American Society of Heating, Refrigerating & Air Conditioning Engineers BCR Benefit Cost Ratio CAV Constant Air Volume CCE Cost of Conserved Energy CEB Ceylon Electricity Board CFL Compact Fluorescent Light COV Coefficient of Variance CRF Capital Recovery Factor CV Constant Volume DPB Discounted Payback Period ECO Energy Conservation Opportunity EMCS Energy Management and Control System FCU Fan Coil Unit FL Fluorescent Light GJ Giga Joules HP Hose Power HVAC Heating, Ventilating and Air Conditioning IAQ Indoor Air Quality IL Incandescent Light IRR Internal Rate of Return LCC Life Cycle Cost MBE Mean Bias Error M&V Measurement and Verification N A Not Applicable NNs Neutral Networks NPV Net Present Value NPW Net Present Worth O&M Operation and Maintenance ROR Rate of Return RT Refrigerant Ton SIR Saving to Investment Ratio SPB Simple Payback Period SPPW Single Payment Present Worth TES Thermal Energy Storage USPW Uniform Series Present Worth VAV Variable Air Volume V B D D Variable Base Degree Days V S D Variable Speed Drives XIII ACKNOWLEDGEMENT I would be very much grateful to Mr. A. Gunasekara, Chief Engineer, Hotel Lanka Oberoi; Colombo for permitting the selection of the hotel for this study. I wish to express my deepest gratitude to Chief Engineer and all the supporting staff of the Hotel Lanka Oberoi, for their fullest support in collecting all the data in the hotel, related to my project. I wish to thank Mr. H. Wickaramasighe, Director and Mr. Wimal Nadeera, Project Engineer, Energy Conservation Fund, for supporting to collect information on energy audit of hotel and power generation of Sri Lanka. I would like to thank Prof. P D C Wijayatunga, Dean and the staff of the faculty of Information Technology, University of Moratuwa, Sri Lanka for permitting to use their computer facility to analyze the energy audit result of the hotel. This research project was carried out under the supervision of Dr. R A Attalage, Head, Department of Mechanical Engineering and Prof. P D C Wijayatunga, Dean, Faculty of Information Technology, University of Moratuwa, Sri Lanka. I am indebted to them, for the valuable guidance, kind-hearted co-operation and encouragement extended throughout the study. I am very thankful to Dr. A G T Sugathapala, M.Eng/PGD Course Coordinator, Energy Technology and Dr. K K C K Perera, Senior Lecturer, Department of Mechanical Engineering, University of Moratuwa, Sri Lanka for giving me the opportunity to do this research. In addition to the above I wish to thank my lecturers who helped me in providing valuable suggestions, recommendations and technical information to make this effort a success. xrv My M Eng would not have been materialized if the financial assistance by the Asian Development Bank through the Ministry of Science and Technology. I gratefully acknowledge the grant offered to me for my post-graduate program. Finally, I would appreciate everybody, who helped me in numerous ways in different stages of the project, which was of utmost importance in bringing out this effort a success. xv