Energy Audits: A Workbook for Energy Management in Buildings -- Contents -- Preface -- Acknowledgements -- Dimensions and Units -- List of Figures -- List of Tables -- 1 Energy and the Environment -- 1.1 Introduction -- 1.2 Forms of energy -- 1.2.1 Mechanical energy -- 1.2.2 Electrical energy -- 1.2.3 Chemical energy -- 1.2.4 Nuclear energy -- 1.2.5 Thermal energy -- 1.3 Energy conversion -- 1.4 The burning question -- 1.4.1 Combustion of coal -- 1.4.2 Combustion of oil -- 1.4.3 Combustion of natural gas -- 1.5 Environmental impact from fossil fuels -- 1.6 Energy worldwide -- 1.7 Energy and the future -- 1.7.1 The dream scenario -- 1.7.2 The renewable scenario -- 1.8 Worked examples -- 1.9 Tutorial problems -- 1.10 Case Study: Future energy for the world -- 2 Energy Audits for Buildings -- 2.1 The need for an energy audit -- 2.2 The energy benchmarking method -- 2.2.1 Benchmarking step by step -- 2.2.2 How savings can be achieved -- 2.3 The degree-days concept -- 2.3.1 Regression of degree-day and energy consumption data -- 2.4 Energy Performance Certificates -- 2.5 Worked examples -- 2.6 Tutorial problems -- 3 Building Fabric's Heat Loss -- 3.1 Modes of heat transfer -- 3.2 Fourier's law of thermal conduction -- 3.2.1 Conduction through a planar wall -- 3.2.2 Radial conduction through a pipe wall -- 3.3 Heat transfer by convection -- 3.3.1 Convective heat transfer: experimental correlations -- 3.3.2 Free convection -- 3.3.3 Forced convection -- 3.4 Heat transfer through a composite wall separating two fluids -- 3.5 Heat exchange through a tube with convection on both sides -- 3.6 A composite tube with fluid on the inner and outer surfaces -- 3.7 Heat transfer by radiation -- 3.8 Building fabric's heat load calculations -- 3.9 Energy efficiency and the environment -- 3.9.1 Space heating -- 3.9.2 Insulation standards.

3.9.3 The economics of heating -- 3.10 Worked examples -- 3.11 Tutorial problems -- 4 Ventilation -- 4.1 Aims of ventilation -- 4.2 Air quality -- 4.2.1 Minimum fresh air requirements -- 4.2.2 Composition of respired air -- 4.3 Ventilation methods -- 4.3.1 Natural ventilation -- 4.3.2 Mechanical or forced ventilation -- 4.4 Ventilation flow calculations -- 4.4.1 Volume flow calculations -- 4.4.2 Ventilation heat load calculations -- 4.4.3 Ventilation calculations based on CO2 build-up -- 4.5 Fans -- 4.5.1 Fan laws -- 4.5.2 Selection of fans -- 4.5.3 Calculation of ventilation fan duty -- 4.5.4 Pressure drop calculation -- 4.5.5 Energy efficiency in ventilation systems -- 4.6 Worked examples -- 4.7 Tutorial problems -- 4.8 Case Study: The National Trust's ventilation system -- 5 Heat Gains in Buildings -- 5.1 Introduction -- 5.2 Lighting -- 5.2.1 Lighting criteria -- 5.2.2 Lighting terminology -- 5.2.3 Measurement of light intensity -- 5.2.4 Types of lamp -- 5.3 Energy-saving measures for lighting -- 5.4 Casual heat gains from appliances -- 5.5 Occupants' heat gains -- 5.6 Worked examples -- 5.7 Tutorial problems -- 5.8 Case Study: Calculation of heating load for a building - options -- 6 Thermal Comfort -- 6.1 Thermal comfort in human beings -- 6.2 Energy balance of the human body -- 6.3 Latent heat losses -- 6.3.1 Heat loss by diffusion -- 6.3.2 Heat loss by evaporation -- 6.3.3 Heat loss by respiration -- 6.4 Sensible heat losses -- 6.4.1 Heat loss by conduction -- 6.4.2 Heat loss by convection -- 6.4.3 Heat loss by radiation -- 6.5 Estimation of thermal comfort -- 6.5.1 Determination of comfort temperature, PMV and PPD -- 6.6 Worked examples -- 6.7 Tutorial problems -- 7 Refrigeration, Heat Pumps and the Environment -- 7.1 Introduction -- 7.2 History of refrigeration -- 7.3 Refrigeration choice and environmental impact -- 7.3.1 TEWI calculation.

7.4 Refrigeration system components -- 7.4.1 The compressor unit -- 7.4.2 The expansion valve -- 7.4.3 The condenser -- 7.4.4 The evaporator -- 7.5 Heat pump and refrigeration cycles -- 7.5.1 The heat engine -- 7.5.2 Reversed heat engine (heat pump/refrigerator) -- 7.5.3 Carnot refrigeration cycle -- 7.5.4 Simple refrigeration cycle -- 7.5.5 Practical refrigeration cycle -- 7.5.6 Irreversibilities in the refrigeration cycle -- 7.5.7 Multi-stage compression -- 7.5.8 Multipurpose refrigeration systems with a single compressor -- 7.6 Worked examples -- 7.7 Tutorial problems -- 7.8 Case Study: Star Refrigeration Ltd - heat pumps in a chocolate factory. May 2010, UK -- 8 Design of Heat Exchangers -- 8.1 Types of heat exchanger -- 8.1.1 Double-pipe heat exchangers -- 8.1.2 Shell-and-tube heat exchangers -- 8.1.3 Cross-flow heat exchangers -- 8.2 Overall heat transfer coefficient -- 8.3 Analysis of heat exchangers -- 8.3.1 The logarithmic mean temperature difference method -- 8.3.2 The F-method for analysis of heat exchangers -- 8.3.3 The effectiveness-NTU method for analysis of heat exchangers -- 8.4 Optimisation of heat transfer surfaces (fins) -- 8.4.1 Fin types -- 8.4.2 Theory of fins -- 8.5 Worked examples -- 8.6 Tutorial problems -- 9 Instrumentation for Energy Management -- 9.1 Introduction -- 9.2 Temperature measurement -- 9.2.1 Expansion thermometers -- 9.2.2 Electrical resistance thermometers -- 9.2.3 Thermocouples -- 9.2.4 Change-of-state thermometers -- 9.2.5 Optical pyrometers -- 9.2.6 Infrared temperature sensors -- 9.2.7 Selection guides for temperature measurement -- 9.3 Humidity measurement -- 9.3.1 Wet and dry bulb hygrometer -- 9.3.2 Liquid-in-steel hygrometers -- 9.3.3 Electrical resistance hygrometer -- 9.3.4 Hair hygrometer -- 9.3.5 Thermal conductivity hygrometer -- 9.3.6 Capacitive humidity sensors -- 9.4 Pressure measurement.

9.4.1 Barometers -- 9.4.2 Bourdon pressure gauge -- 9.4.3 Pressure transducers -- 9.4.4 Manometers -- 9.5 Flow measurement -- 9.5.1 Flow measurement by collection -- 9.5.2 Flow measurement by rotameter -- 9.5.3 Flow measurement by turbine flow meter -- 9.5.4 Flow measurement by differential pressure flow meter -- 9.5.5 Velocity and flow measured by anemometers -- 9.6 Electrical measurements -- 9.6.1 Energy in electrical circuits -- 9.6.2 Ohm's law -- 9.6.3 Electrical power -- 9.6.4 Alternating current power -- 9.6.5 Electrical measurements -- 9.7 Worked examples -- 9.8 Tutorial problems -- 10 Renewable Energy Technology -- 10.1 Introduction -- 10.2 Solar energy -- 10.2.1 Solar declination -- 10.2.2 Solar altitude angle and azimuth angle -- 10.2.3 Solar time and angles -- 10.2.4 Solar radiation -- 10.2.5 Incidence angle -- 10.2.6 Fixed aperture -- 10.2.7 Solar tracking -- 10.2.8 The aperture intensity -- 10.2.9 Energy conversion efficiency -- 10.2.10 Installation of photovoltaic modules -- 10.2.11 Technology status -- 10.2.12 PV system components -- 10.3 Wind energy -- 10.3.1 Ideal wind power calculation -- 10.3.2 Theory of wind turbines -- 10.3.3 Wind turbine components -- 10.3.4 Types of wind turbine -- 10.4 Biomass -- 10.4.1 Sources of biomass -- 10.4.2 Combustion equation for biomass -- 10.5 Hydraulic turbines -- 10.5.1 Theory of hydraulic turbines -- 10.5.2 Fluid power -- 10.5.3 Classification of hydraulic turbines -- 10.5.4 Design and selection of hydraulic turbines -- 10.5.5 Relationship between specific speed and type of hydraulic turbine -- 10.6 Worked examples -- 10.7 Tutorial problems -- Appendix: Case Study: Energy audit for a school -- Index.