Energy Measurement & Audit

1 Energy Measurement & Audit Reference Manual Authors Mr Steven Kang Ms Teng Seer Ping Dr Md Raisul Islam Ms May Pwint 2 Preface I have been struck again and again by how important Measurement is to improving the human condition. Bill Gates Sciences and achievements have a common foundation: Measurement . What is the right direction, how far do we have to go, how long will we take, how much Energy will we require. As engineers, these are questions we constantly ask as we strive to advance our craft. When we ask the right questions, develop new solutions and measure their effectiveness, we will continue to progress. This manual is intended to broaden your knowledge in the practice and discipline of Energy Audit and analysis of mechanical systems in commercial and industrial facilities.

2 The manual is divided into eight main chapters: 1. The Need for Energy Measurement and Analysis (EM&A) 2. Introduction to Different Levels of Energy Measurement and Analysis (EM&A) 3. Overview of Measurement Instruments 4. Measurement and Analysis of Chilled water system 5. Measurement and Analysis of AHUs, FCUs and Mechanical Ventilation Systems 6. Lighting Systems 7. Industrial Systems 8. Data Plotting and Analysis Assignments 9. Safety Considerations I believe they will provide a good foundation for Energy Managers to evaluate Energy efficiency of facilities, as well as develop and implement Energy efficiency measures and verify their effectiveness. Some of the material in this manual (listed below) has been obtained with kind permission from Spring Singapore, Building Construction Authority of Singapore and Air Movement and Control Association: 1.

3 SS591-2013: Code of practice for long term Measurement of central chilled water system Energy efficiency. 2. SS530-2014: Code of practice for Energy efficiency standard for building services and equipment 3 3. SS553-2009: Code of practice for air-conditioning and mechanical ventilation in buildings 4. Green Mark for Non-Residential Buildings (New and Existing) 5. AMCA Publication 203: Field performance Measurement of Fan Systems I would like to extend my sincere gratitude to my fellow authors, Ms Teng Seer Ping, Ms May Pwint and Dr Md Raisul Islam, all of whom have contributed tremendously to the development of this manual. Much credit also goes to the editing and proof reading work done by Ms April Khor and the dedicated team from National Environment Agency, The Institution of Engineers, Singapore and Building Construction Authority.

4 Without them, this manual would certainly not have been possible. 4 Table of Contents 1 The Need for Energy Measurement and Analysis (EM&A) _____ 9 The Opportunity Cost of Poor EM&A _____ 10 What Is Good EM&A and How It Helps To Improve Energy Efficiency_____ 13 Key Standards Regarding EM&A _____ 15 SS591-2013: Code of practice for long term Measurement of central chilled water system Energy efficiency_____ 16 SS530-2014 Code of practice for Energy efficiency standard for building services and equipment _ 22 Minimum Efficiency For Chillers _____ 22 SS553-2016 Code of practice for air-conditioning and mechanical ventilation in buildings _____ 25 BCA Green Mark for New Non-Residential Building GM NRB.

5 2015 _____ 30 BCA Green Mark for Existing Non-Residential Building v _____ 32 Minimum Air-conditioning Plant Operating System Efficiency _____ 32 2 Introduction to Different Levels of Energy Measurement and Analysis (EM&A) _____ 34 Level I Audit _____ 35 Level II Audit _____ 37 Level III Audit _____ 40 3 Overview of Measurement Instruments _____ 41 Power Meter _____ 42 Operating Principles and Accuracy Range _____ 43 Current Transformer _____ 43 Integrated Power Meter _____ 47 Determination of True Root Mean Square (RMS) Power _____ 48 Calibration of Power Meter _____ 51 Temperature Sensor _____ 52 Operating Principles and Accuracy Range _____ 54 Thermocouple _____ 54 Resistance Temperature Detectors (RTDs) _____ 58 Thermistors _____ 63 Calibration of Temperature Sensor _____ 69 The International Temperature Scale (ITS-90) _____ 69 Platinum Resistance Thermometer (PRT)

6 _____ 71 5 Calibration Equipment _____ 72 Typical Set-up for Temperature Sensor Calibration _____ 73 Water Flow Meter _____ 74 Operating Principles and Accuracy _____ 76 Electromagnetic Flow Meter _____ 76 Ultrasonic Flow Meter _____ 80 Vortex Flow Meter _____ 84 Orifice Flow Meter _____ 86 Coriolis Flow Meter _____ 88 Calibration of Flow Meter _____ 91 Air Flow Meter _____ 93 Operating Principles and Accuracy _____ 93 Calibration of Air Flow Meter _____ 94 Primary Standard Flow Measurement _____ 94 Secondary Standard Flow Measurement _____ 95 Pressure Meter _____ 96 Operating Principles and Accuracy _____ 97 Calibration of Pressure Meter _____ 100 Primary Pressure Standards_____ 100 Secondary Pressure Standards _____ 102 Lux Meter _____ 103 Operating Principles and Accuracy _____ 103 Calibration of Lux Meter _____ 104 4 Measurement and Analysis of Chilled Water System _____ 105 Level I to Level III Scope of Work _____ 106 Level I Assessment Preliminary or Walk-through _____ 106 Level II Assessment Standard _____ 107 Level III Assessment Comprehensive or Detailed _____ 107 Checklist for Assessment of Chilled Water System _____ 108 Types of Instruments and Accuracy _____ 110 Data Collection _____ 113 Useful Metrics _____ 113 Types of Data to be Collected_____ 114 Duration and

7 Frequency of Data Collection _____ 115 6 Data Analysis _____ 115 Data Arrangements _____ 115 Graphical Representation _____ 116 Heat Balance Validation _____ 121 Benchmarking _____ 123 Codes and Standards _____ 123 Case Studies _____ 125 Good Practices _____ 125 Common Pitfalls _____ 125 5 Measurement and Analysis of AHUs, FCUs and Mechanical Ventilation Systems ___ 126 Level I Audit For AHUs / FCUs and Ventilation Fans _____ 127 Level II Audit of AHUs / FCUs and Ventilation Fans _____ 130 Examples of Level III Audit for AHUs, FCUs and Ventilation Fans _____ 134 Instruments _____ 135 Data To be Measured _____ 143 Data Analysis _____ 145 Benchmarking To Standards and Best Practices _____ 150 Good Practices and Common Pitfalls _____ 152 6 Lighting Systems _____ 157 Definitions _____ 157 Scope of Work for Level I to 3 Audits _____ 159 Instruments _____ 160 Data to be Collected _____ 161 Data Analysis _____ 161 Best Practices _____ 162 Case Study _____ 163 7 Industrial Systems _____ 165 Steam and Hot Water Systems _____ 165 7 Boiler Systems _____ 165 Boiler Basic Operations _____ 166 Boiler Draught _____ 167 Enthalpy of Water and Steam _____ 168 Energy Balance and

8 Measurement of Boiler Efficiency _____ 172 Calculation of Blowdown Rate _____ 173 Measurement of Recoverable Energy from Blowdown_____ 174 Measurement of Power of Auxiliary Equipment _____ 176 Measurement of Condensate Recovery Rate _____ 177 Measurement of Radiation and Convection Losses _____ 178 Measurement of Excess Air for Combustion _____ 179 Measurement of Recoverable Energy from Flue Gas _____ 179 Measuring Sensors for Boiler Systems _____ 181 Accuracy of Sensors _____ 182 Heat Pump Systems _____ 183 Measurement of Heat Pump performance _____ 184 Measuring Sensors for Heat Pump Systems _____ 187 Compressed Air Systems _____ 187 Types of Compressor_____ 188 Measurement of Specific Power and FAD _____ 188 Measurement of Utilisation Factor _____ 191 Measurement of Air Leaks _____ 192 Measurement of Temperature and Pressure for Energy Savings _____ 193 Measurement of Dryness of Compressed Air _____ 196 Measuring Sensors for Compressed Air Systems _____ 197 8 Data Plotting and Analysis Assignments _____ 198 Formulae _____ 199 Cooling Load (RT) _____ 200 Frequency of Cooling Load Occurrence _____ 203 Plant Efficiency (KW/RT) _____ 207 Efficiency (KW/RT) vs Cooling Load (RT)

9 _____ 208 Heat Balance Percentage _____ 210 Summary of performance Table _____ 211 8 9 Safety Considerations _____ 214 Risk Control Options_____ 214 Risk Matrix _____ 215 Risk Assessment _____ 217 2016 The Institution of Engineers, Singapore and National Environment Agency. All rights reserved. No part of this manual may be reproduced, distributed, transcribed, stored in a retrieval system, translated into any language or computer language or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the copyright owner. The copyright owners give no warranties and make no representations about the contents of this manual and specifically disclaim any implied warranties or merchantability or fitness for any purpose.

10 The copyright owners reserve the right to revise this manual and to make changes from time to time in its contents without notifying any person of such revisions or changes. 9 1 The Need for Energy Measurement and Analysis (EM&A) Introduction As Singapore is renewable- Energy constrained and imports virtually all of our Energy , our primary strategy to reduce our carbon footprint and Energy cost, and improve our Energy resilience is to improve our Energy efficiency. One of the fundamental actions required to improve Energy efficiency is to measure and verify how efficiently Energy is being used. The data from accurate Measurement will provide the knowledge to hone Energy efficiency skills and also provide data to develop a reliable financial business case that can motivate management to invest with confidence.