2020 ASHRAE Handbook -- HVAC Systems and Equipment (ASHRAE Handbook of Heating, Ventilating and Air-Conditioning Systems and Equipment SI)

2020 ASHRAE Handbook: HVAC Systems and Equipment --- MAIN MENU --- Home Dedicated To The Advancement Of The Profession And Its Allied Industries DISCLAIMER SI Table of Contents CONTRIBUTORS ASHRAE TECHNICAL COMMITTEES, TASK GROUPS, AND TECHNICAL RESOURCE GROUPS ASHRAE Research: Improving the Quality of Life Preface CHAPTERS --- CHAPTER 01: HVAC SYSTEM ANALYSIS AND SELECTION --- 1. Selecting a System Additional Goals Equipment and System Constraints Constructability Constraints Narrowing the Choices 2. HVAC Systems and Equipment Centralized System Characteristics Air Distribution Systems 3. Space Requirements Equipment Rooms Fan Rooms Horizontal Distribution Vertical Shafts Rooftop Equipment Equipment Access 4. Air Distribution Air Terminal Units 8. Maintenance Management 9. Building System Commissioning References Bibliography Tables Table 1 Sample HVAC System Analysis and Selection Matrix (0 to 10 Score) Figures Fig. 1 Process Flow Diagram --- CHAPTER 02: DECENTRALIZED COOLING AND HEATING --- 1. System Characteristics Advantages Disadvantages 2. Design Considerations Air-Side Economizer Advantages Disadvantages Water-Side Economizer Advantages Disadvantages 3. Window-Mounted and Through-the- Wall Room HVAC Units Advantages Disadvantages Design Considerations 4. Water-Source Heat Pump Systems Advantages Disadvantages Design Considerations 5. Multiple-Unit Systems Advantages Disadvantages Design Considerations 6. Residential and Light Commercial Split Systems Advantages Disadvantages Design Considerations 7. Commercial Self-Contained (Floor- by-Floor) Systems Advantages Disadvantages Design Considerations 8. Commercial Outdoor Packaged Systems Advantages Disadvantages Design Considerations 9. Single-Zone VAV Systems Advantages Disadvantages Design Considerations 10. Automatic Controls and Building Management Systems 11. Maintenance Management 12. Building System Commissioning Bibliography Figures Fig. 1 Multiple-Unit Systems: Single-Zone Unitary HVAC Equipment for Interior and Packaged Terminal Air Conditioners (PTACs) for Perimeter Fig. 2 Vertical Self-Contained Unit Fig. 3 Dedicated Outdoor-Air-Conditioning Unit Fig. 4 Commercial Self-Contained Unit with Discharge Plenum --- CHAPTER 03: CENTRAL COOLING AND HEATING PLANTS --- 1. System Characteristics Advantages Disadvantages 2. Design Considerations Cooling and Heating Loads Security System Flow Design Energy Recovery and Thermal Storage 3. Equipment Primary Refrigeration Equipment Ancillary Refrigeration Equipment Primary Heating Equipment Ancillary Heating Equipment 4. Distribution Systems 5. Sound, Vibration, Seismic, and Wind Considerations Sound and Vibration Seismic and Wind Issues 6. Space Considerations Location of Central Plant and Equipment Central Plant Security 7. Automatic Controls and Building Management Systems Instrumentation 8. Maintenance Management Systems 9. Building System Commissioning 10. System Replacements and Expansions References Bibliography Figures Fig. 1 Primary Variable-Flow System Fig. 2 Primary (Limited) Variable-Flow System Using Distribution Pressure Control Fig. 3 Primary/Secondary Pumping Chilled-Water System Fig. 4 Primary/Secondary Pumping Hot-Water System --- CHAPTER 04: AIR HANDLING AND DISTRIBUTION --- Advantages of All-Air Systems Disadvantages of All-Air Systems Heating and Cooling Calculations Zoning Space Heating Air Temperature Versus Air Quantity Space Pressure Other Considerations First, Operating, and Maintenance Costs Energy in Air Handling 1. AIR-HANDLING UNITS 1.1 Air-Handling Unit Psychrometric Processes Cooling Heating Humidification Dehumidification Air Mixing or Blending 1.2 Air-Handling Unit Components Return Air Fan Relief Air Fan Automatic Dampers Relief Openings Return Air Dampers Outdoor Air Intakes Economizers Mixing Plenums Static Air Mixers Filter Section Preheat Coil Cooling Coil Reheat Coil Humidifiers Dehumidifiers Energy Recovery Devices Sound Control Devices Supply Air Fan Miscellaneous Components 1.3 Air Distribution Ductwork Design Primary Equipment Air-Handling Equipment Central Mechanical Equipment Rooms (MERs) Decentralized MERs Fans 2. AIR-HANDLING SYSTEMS 2.1 Single-Duct Systems Constant Volume Variable Air Volume (VAV) 2.2 Dual-Duct Systems Constant Volume Variable Air Volume 2.3 Multizone Systems 2.4 Special Systems Primary/Secondary Dedicated Outdoor Air Underfloor Air Distribution Wetted Duct/Supersaturated Compressed-Air and Water Spray Low-Temperature Smoke Control 2.5 Air Terminal Units Constant-Volume Reheat Variable Air Volume Terminal Humidifiers Terminal Filters 2.6 Air Distribution System Controls 2.7 Automatic Controls and Building Management Systems 2.8 Maintenance Management System 2.9 Building System Commissioning References Bibliography Figures Fig. 1 Typical Air-Handling Unit Configurations Fig. 2 Direct-Expansion or Chilled-Water Cooling and Dehumidification Fig. 3 Direct Spray of Water in Airstream Cooling Fig. 4 Supersaturated Evaporative Cooling Fig. 5 Steam, Hot-Water, and Electric Heating, and Direct and Indirect Gas- and Oil-Fired Heat Exchangers Fig. 6 Direct Spray Humidification Fig. 7 Steam Injection Humidification Fig. 8 Chemical Dehumidification Fig. 9 Constant-Volume System with Reheat Fig. 10 Variable-Air-Volume System with Reheat and Induction and Fan-Powered Devices Fig. 11 Single-Fan, Dual-Duct System Fig. 12 Dual-Fan, Dual-Duct System Fig. 13 Multizone System Fig. 14 Primary/Secondary System Fig. 15 Underfloor Air Distribution Fig. 16 Supersaturated/Wetted Coil --- CHAPTER 05: IN-ROOM TERMINAL SYSTEMS --- 1. System Characteristics Advantages Disadvantages Heating and Cooling Calculations Space Heating Central (Primary-Air) Ventilation Systems Central Plant Sizing Building Pressurization First, Operating, and Maintenance Costs Energy Life-Cycle Costs 2. System Components and Configurations Components Configurations 3. Secondary-Water Distribution 4. Piping Arrangements Four-Pipe Distribution Two-Pipe Distribution Three-Pipe Distribution Condenser Water Systems with Heat Pump Terminal Units 5. Fan-Coil Unit and Unit Ventilator Systems Types and Location Ventilation Air Requirements Selection Wiring Condensate Capacity Control Maintenance 6. Variable-Refrigerant-Flow (VRF) Units 7. Chilled-Beam Systems Types and Location Ventilation Air Requirements Selection Wiring Condensate Capacity Control Maintenance Other Concerns 8. Radiant-Panel Heating Systems Types and Location Ventilation Air Requirements Selection Wiring Capacity Control Maintenance 9. Radiant-Floor Heating Systems Types and Location Ventilation Air Requirements Selection Wiring Capacity Control Maintenance 10. Induction Unit Systems 11. Supplemental Heating Units 12. Primary-Air Systems 13. Performance Under Varying Load 14. Changeover Temperature 15. Two-Pipe Systems with Central Ventilation Critical Design Elements Changeover Temperature Considerations Nonchangeover Design Zoning Room Control Evaluation Electric Heat for Two-Pipe Systems 16. Four-Pipe Systems Zoning Room Control Evaluation 17. Automatic Controls and Building Management Systems 18. Maintenance Management Systems and Building System Commissioning References Bibliography Figures Fig. 1 Typical Fan-Coil Unit Fig. 2 Passive and Active Chilled-Beam Operation Fig. 3 Primary-Air System Fig. 4 Solar Radiation Variations with Seasons Fig. 5 Capacity Ranges of In-Room Terminal Operating on Two-Pipe System Fig. 6 Primary-Air Temperature Versus Outdoor Air Temperature Fig. 7 Psychrometric Chart, Two-Pipe System, Off-Season Cooling Fig. 8 Typical Changeover System Temperature Variation Fig. 9 Typical Nonchangeover System Variations Fig. 10 Fan-Coil Unit Control --- CHAPTER 06: RADIANT HEATING AND COOLING --- 1. PRINCIPLES OF RADIANT SYSTEMS 1.1 Heat Transfer Heat Transfer by Thermal Radiation Heat Transfer by Natural Convection Combined Heat Flux (Thermal Radiation and Natural Convection) 1.2 Factors Affecting Heat Transfer Panel Thermal Resistance Effect of Floor Coverings Panel Heat Losses or Gains Panel Performance 1.3 Panel Design Special Cases Examples 2. General Design Considerations 2.1 Hybrid Systems 3. RADIANT HEATING AND COOLING SYSTEMS 3.1 Hydronic Ceiling Panels 3.2 Embedded Systems with Tubing in Ceilings, Walls, or Floors Hydronic Wall Panels Hydronic Floor Panels 3.3 Electrically Heated Radiant Systems Electric Ceiling Panels Electric Wall Heating Electric Floor Heating 4. DESIGN PROCEDURE Sensible Cooling Sensible Heating Other Steps Common for Sensible Heating and Cooling 4.1 Controls Sensible Cooling Controls Heating Slab Controls References Bibliography Tables Table 1 Thermal Resistance of Ceiling Panels Table 2 Thermal Conductivity of Typical Tube Material Table 3 Thermal Resistance of Floor Coverings Table 4 Characteristics of Typical Electric Panels Figures Fig. 1 Radiation Heat Flux at Heated Ceiling, Floor, or Wall Panel Surfaces Fig. 2 Heat Removed by Radiation at Cooled Ceiling or Wall Panel Surface Fig. 3 Natural-Convection Heat Transfer at Floor, Ceiling, and Wall Panel Surfaces Fig. 4 Empirical Data for Heat Removal by Ceiling Cooling Panels from Natural Convection Fig. 5 Relation of Inside Surface Temperature to Overall Heat Transfer Coefficient Fig. 6 Inside Surface Temperature Correction for Exposed Wall at Dry-Bulb Air Temperatures Other Than 21°C Fig. 7 Cooled Ceiling Panel Performance in Uniform Environment with No Infiltration and No Internal Heat Sources Fig. 8 Downward and Edgewise Heat Loss Coefficient for Concrete Floor Slabs on Grade Fig. 9 Design Graph for Sensible Heating and Cooling with Floor and Ceiling Panels Fig. 10 Design Graph for Heating with Aluminum Ceiling and Wall Panels Fig. 11 Typical Residential Hybrid HVAC System Fig. 12 Metal Ceiling Panels Attached to Pipe Laterals Fig. 13 Metal Ceiling Panels Bonded to Copper Tubing Fig. 14 Extruded Aluminum Panels with Integral Copper Tube Fig. 15 Permitted Design Ceiling Surface Temperatures at Various Ceiling Heights Fig. 16 Coils in Structural Concrete Slab Fig. 17 Coils in Plaster Above Lath Fig. 18 Coils in Plaster Below Lath Fig. 19 Coils in Floor Slab on Grade Fig. 20 Embedded Tube in Thin Slab Fig. 21 Tube in Subfloor Fig. 22 Tube Under Subfloor Fig. 23 Electric Heating Panels Fig. 24 Electric Heating for Wet Plaster Ceiling Fig. 25 Electric Heating Cable in Concrete Slab Fig. 26 Primary/Secondary Water Distribution System with Mixing Control Fig. 27 Split Panel Piping Arrangement for Two-Pipe and Four-Pipe Systems --- CHAPTER 07: COMBINED HEAT AND POWER SYSTEMS --- 1. Terminology 2. CHP System Concepts 2.1 Custom-Engineered Systems 2.2 Packaged and Modular Systems 2.3 Load Profiling and Prime Mover Selection 2.4 Peak Load Shaving 2.5 Continuous-Duty Standby 2.6 Power Plant Incremental Heat Rate 3. Performance Parameters 3.1 Heating Value 3.2 CHP Electric Effectiveness Power and Heating Systems 3.3 Fuel Energy Savings 4. Fuel-to-Power Components 4.1 Reciprocating Engines Types Performance Characteristics Fuels and Fuel Systems Combustion Air Lubricating Systems Starting Systems Cooling Systems Exhaust Systems Emissions Instruments and Controls Noise and Vibration Installation Ventilation Requirements Operation and Maintenance 4.2 Combustion Turbines Types Advantages Disadvantages Gas Turbine Cycle Components 4.3 Performance Characteristics Fuels and Fuel Systems Combustion Air Lubricating Systems Starting Systems Exhaust Systems Emissions Instruments and Controls Noise and Vibration Operation and Maintenance 4.4 Fuel Cells Types 5. Thermal-to-Power Components 5.1 Steam Turbines Types Performance Characteristics Fuel Systems Lubricating Oil Systems Power Systems Exhaust Systems Instruments and Controls Operation and Maintenance 5.2 Organic Rankine Cycles 5.3 Expansion Engines/Turbines 5.4 Stirling Engines Types Performance Characteristics Fuel Systems Power Systems Exhaust Systems Coolant Systems Operation and Maintenance 6. Thermal-to-Thermal Components 6.1 Thermal Output Characteristics Reciprocating Engines Combustion Turbines 6.2 Heat Recovery Reciprocating Engines Combustion Turbines Steam Turbines 6.3 Thermally Activated Technologies Heat-Activated Chillers Desiccant Dehumidification Hot Water and Steam Heat Recovery Thermal Energy Storage Technologies 7. Electrical Generators and Components 7.1 Generators 8. System Design 8.1 CHP Electricity-Generating Systems Thermal Loads Prime Mover Selection Air Systems Hydronic Systems Service Water Heating District Heating and Cooling Utility Interfacing Power Quality Output Energy Streams 8.2 CHP Shaft-Driven HVAC and Refrigeration Systems Engine-Driven Systems Combustion-Turbine-Driven Systems Steam-Turbine-Driven Systems 9. Codes and Installation 9.1 General Installation Parameters 9.2 Utility Interconnection 9.3 Air Permits 9.4 Building, Zoning, and Fire Codes Zoning Building Code/Structural Design Mechanical/Plumbing Code Fire Code Electrical Connection 10. Economic Evaluation CHP Application Assessment Types and Scope of CHP Studies CHP System Modeling Techniques CHP Feasibility Study for New Facilities Tools and Software for Feasibility Study 10.1 Load Profiles and Load Duration Curves Load Duration Curve Analysis Two-Dimensional Load Duration Curve Analysis by Simulations References Bibliography Tables Table 1 Applications and Markets for DG/CHP Systems Table 2 Values of  for Conventional Thermal Generation Technologies Table 3 Summary of Results from Examples 1 to 5 Table 4 Summary of Results Assuming 33% Efficient Combustion Turbine Table 5 Typical  Values Table 6 Summary of Fuel Energy Savings for 25% Power Generator in Examples 1 to 5 Table 7 Summary of Fuel Energy Savings for 33% Power Generator in Examples 1 to 5 Table 8 Reciprocating Engine Types by Speed (Available MW Ratings) Table 9 Line Regulator Pressures Table 10 Ventilation Air for Engine Equipment Rooms Table 11 Exhaust Pipe Diameter Table 12 Recommended Engine Maintenance Table 13 Overview of Fuel Cell Characteristics Table 14 Theoretical Steam Rates For Turbines at Common Conditions, kgkWh Table 15 NEMA Classification of Speed Governors Table 16 Temperatures Normally Required for Various Heating Applications Table 17 Full-Load Exhaust Mass Flows andTemperatures for Various Engines Table 18 Generator Control Functions Table 19 Coefficient of Performance (COP) of Engine-Driven Chillers Table 20 Typical Efficiency of Engine-Driven Refrigeration Equipment (Ammonia Screw Compressor) Figures Fig. 1 CHP Cycles Fig. 2 Dual-Service Applications Fig. 3 Conventional Boiler for Example 1 Fig. 4 Power-Only Generator for Example 1 Fig. 5 Performance Parameters for Combined Systemfor Example 2 Fig. 6 CHP Power and Heating Energy Boundary Diagram for Example 2 Fig. 7 Performance Parameters for Example 3 Fig. 8 CHP Power and Direct Heating Energy Boundary Diagram for Example 3 Fig. 9 Performance Parameters for Example 4 Fig. 10 CHP Power and HRSG Heating Without Duct Burner Energy Boundary Diagram for Example 4 Fig. 11 Cofiring Performance Parameters for Example 5 Fig. 12 CHP Power and HRSG Heating with Duct Burner Energy Boundary Diagram for Example 5 Fig. 13 Electric Effectiveness E Versus Overall Efficiency O Fig. 14 Efficiency (HHV) of Spark Ignition Engines Fig. 15 Heat Rate (HHV) of Spark Ignition Engines Fig. 16 Thermal-to-Electric Ratio of Spark Ignition Engines (Jacket and Exhaust Energy) Fig. 17 Part-Load Heat Rate (HHV) of 1430, 425, and 85 kW Gas Engines Fig. 18 Part-Load Thermal-to-Electric Ratio of 1430, 425, and 85 kW Gas Engines Fig. 19 Typical Reciprocating Engine Exhaust Noise Curves Fig. 20 Typical Attenuation Curves for Engine Silencers Fig. 21 Temperature-Entropy Diagram for Brayton Cycle Fig. 22 Simple-Cycle Single-Shaft Turbine Fig. 23 Simple-Cycle Dual-Shaft Turbines Fig. 24 Turbine Engine Performance Characteristics Fig. 25 Gas Turbine Refrigeration System Using Exhaust Heat Fig. 26 CHP System Boundary Fig. 27 PAFC Fig. 28 SOFC Fig. 29 MCFC Fig. 30 PEMFC Fig. 31 AFC Fig. 32 Basic Types of Axial Flow Turbines Fig. 33 Isentropic Versus Actual Turbine Process Fig. 34 Efficiency of Typical Multistage Turbines Fig. 35 Effect of Inlet Pressure and Superheat on Condensing Turbine Fig. 36 Effect of Exhaust Pressure on Noncondensing Turbine Fig. 37 Single-Stage Noncondensing Turbine Efficiency Fig. 38 Effect of Extraction Rate on Condensing Turbine Fig. 39 Oil Relay Governor Fig. 40 Part-Load Turbine Performance Showing Effect of Auxiliary Valves Fig. 41 Multivalve Oil Relay Governor Fig. 42 Cutaway Core of a Kinematic Stirling Engine Fig. 43 Cutaway Core of a Free-Piston Stirling Engine Fig. 44 Heat Balance for Naturally Aspirated Engine Fig. 45 Heat Balance for Turbocharged Engine Fig. 46 Hot-Water Heat Recovery Fig. 47 Hot-Water Engine Cooling with Steam Heat Recovery (Forced Recirculation) Fig. 48 Engine Cooling with Gravity Circulation and Steam Heat Recovery Fig. 49 Lubricant and Aftercooler System Fig. 50 Exhaust Heat Recovery with Steam Separator Fig. 51 Effect of Soot on Energy Recovery from Flue Gas Recovery Unit on Diesel Engine Fig. 52 Automatic Boiler System with Overriding Exhaust Temperature Control Fig. 53 Combined Exhaust and Jacket Water Heat Recovery System Fig. 54 Effect of Lowering Exhaust Temperature below 150°C Fig. 55 Back-Pressure Turbine Fig. 56 Integration of Back-Pressure Turbine with Facility Fig. 57 Condensing Automatic Extraction Turbine Fig. 58 Automatic Extraction Turbine CHP System Fig. 59 Performance Map of Automatic Extraction Turbine Fig. 60 Hybrid Heat Recovery Absorption Chiller-Heater Fig. 61 Typical Generator Efficiency Fig. 62 Typical Heat Recovery Cycle for Gas Turbine Fig. 63 Performance Curve for Typical 350 kW, Gas-Engine-Driven, Reciprocating Chiller Fig. 64 Typical Gas Turbine Refrigeration Cycle Fig. 65 Condensing Turbine-Driven Centrifugal Compressor Fig. 66 Combination Centrifugal-Absorption System Fig. 67 Hypothetical Steam Load Profile Fig. 68 Load Duration Curve Fig. 69 Load Duration Curve with Multiple Generators Fig. 70 Hypothetical Peaking Generator Fig. 71 Example of Two-Dimensional Load Duration Curve --- CHAPTER 08: COMBUSTION TURBINE INLET COOLING --- 1. Advantages Economic Benefits Environmental Benefits 2. Disadvantages 3. Definition and Theory 4. System Types Evaporative Systems Chiller Systems LNG Vaporization Systems Hybrid Systems 5. Calculation of Power Capacity Enhancement and Economics References Bibliography Tables Table 1 Typical Combined-Cycle, Simple-Cycle, and Steam Turbine Systems Figures Fig. 1 Effect of Ambient Temperature on CT Output Fig. 2 Effect of Ambient Temperature on CT Heat Rate Fig. 3 Effects of Ambient Temperature on Thermal Energy, Mass Flow Rate and Temperature of CT Exhaust Gases Fig. 4 Typical Hourly Power Demand Profile Fig. 5 Example of Daily System Load and Electric Energy Pricing Profiles Fig. 6 Schematic Flow Diagram of Typical Combustion Turbine System Fig. 7 Psychrometric Chart Showing Direct and Indirect Inlet Air Cooling Processes Fig. 8 Typical Wetted Media Fig. 9 Water Fog Created for Fogging System Fig. 10 Cooling Coil Used for Indirect Cooling Chiller Systems Fig. 11 Examples of Effect of CTIC Technology and Ambient Condition on Capacity Enhancement Potential Fig. 12 Example of Effects of CTIC Technology and Ambient Condition on Unitized Capital Cost of Capacity Enhancement --- CHAPTER 09: APPLIED HEAT PUMP AND HEAT RECOVERY SYSTEMS --- 1. TERMINOLOGY 2. APPLIED HEAT PUMP SYSTEMS 2.1 Heat Pump Cycles 2.2 Heat Sources and Sinks Air Water Ground Solar Energy 2.3 Types of Heat Pumps 2.4 Heat Pump Components Compressors Heat Transfer Components Refrigeration Components Controls Supplemental Heating 2.5 Industrial Process Heat Pumps Closed-Cycle Systems Open-Cycle and Semi-Open-Cycle Heat Pump Systems Heat Recovery Design Principles 3. APPLIED HEAT RECOVERY SYSTEMS 3.1 Waste Heat Recovery General Considerations Applications of Waste Heat Recovery Alternative Heat Sources Locating the Heat Recovery Heat Pump Specific Considerations of Condenser-Side Recovery Specific Considerations of Evaporator-Side Recovery Special Considerations of Double-Bundle Heat Recovery Selecting a Compressor Type Pumping Considerations HRHP Selection Example 3.2 Water-Loop Heat Pump Systems Description Design Considerations Controls Advantages of a WLHP System Limitations of a WLHP System 3.3 Balanced Heat Recovery Systems Definition Heat Redistribution Heat Balance Concept Heat Balance Studies General Applications Multiple Buildings 3.4 Heat Pumps in District Heating and Cooling Systems References Bibliography Tables Table 1 Heat Pump Sources and Sinks Figures Fig. 1 Closed Vapor Compression Cycle Fig. 2 Mechanical Vapor Recompression Cycle with Heat Exchanger Fig. 3 Open Vapor Recompression Cycle Fig. 4 Heat-Driven Rankine Cycle Fig. 5 Heat Pump Types Fig. 6 Comparison of Parallel and Staged Operation for Air-Source Heat Pumps Fig. 7 Suction Line Separator for Protection Against Liquid Floodback Fig. 8 Liquid Subcooling Coil in Ventilation Air Supply to Increase Heating Effect and Heating COP Fig. 9 Typical Increase in Heating Capacity Resulting from Using Liquid Subcooling Coil Fig. 10 Dehumidification Heat Pump Fig. 11 Air-to-Water Heat Pump Fig. 12 Cooling Tower Heat Recovery Heat Pump Fig. 13 Effluent Heat Recovery Heat Pump Fig. 14 Refrigeration Heat Recovery Heat Pump Fig. 15 Condensing Ammonia Heat Pump Fig. 16 Closed-Cycle Vapor Compression System Fig. 17 Recompression of Boiler-Generated Process Steam Fig. 18 Single-Effect Heat Pump Evaporator Fig. 19 Multiple-Effect Heat Pump Evaporator Fig. 20 Distillation Heat Pump System Fig. 21 Heat Recovery Heat Pump System in a Rendering Plant Fig. 22 Semi-Open-Cycle Heat Pump in a Textile Plant Fig. 23 Possible Heat Recovery Heat Pump Locations Fig. 24 Primary/Secondary, Equal Loading Fig. 25 Variable Primary Flow Example Fig. 26 HRHP Application Flowchart Fig. 27 Heat Balance Chart Fig. 28 Selection of Simultaneous Heating and Cooling HRHP Fig. 29 Operating Areas for Simultaneous HRHP Fig. 30 Heat Recovery System Using Water-to-Air Heat Pumps in a Closed Loop Fig. 31 Closed-Loop Heat Pump System with Thermal Storage and Optional Solar-Assist Collectors Fig. 32 Secondary Heat Recovery from WLHP System Fig. 33 Cooling Tower with Heat Exchanger Fig. 34 Major Load Components Fig. 35 Composite Plot of Loads in Figure 34 Fig. 36 Non-Heat-Recovery System --- CHAPTER 10: SMALL FORCED-AIR HEATING AND COOLING SYSTEMS --- 1. Components Heating and Cooling Units Ducts Accessory Equipment Controls 2. Common System Problems 3. System Design Estimating Heating and Cooling Loads Locating Outlets, Returns, Ducts, and Equipment Selecting Heating and Cooling Equipment Determining Airflow Requirements Finalize Duct Design and Size Selecting Supply and Return Grilles and Registers 4. Detailed Duct Design Detailing the Duct Configuration Detailing the Distribution Design Duct Design Recommendations Zone Control for Small Systems Duct Sizing for Zone Damper Systems Box Plenum Systems Using Flexible Duct Embedded Loop Ducts 5. Small Commercial Systems Air Distribution in Small Commercial Buildings Controlling Airflow in New Buildings 6. Testing for Duct Efficiency Data Inputs Data Output Standards References Bibliography Tables Table 1 General Characteristics of Supply Outlets Table 2 Recommended Division of Duct Pressure Loss Figures Fig. 1 Heating and Cooling Components Fig. 2 Sample Floor Plans for Locating Ductwork in Second Floor of (A) Two-Story House and (B) Townhouse Fig. 3 Sample Floor Plans for One-Story House with (A) Dropped Ceilings, (B) Ducts in Conditioned Spaces, and(C) Right-Sized Air Distribution in Conditioned Spaces Fig. 4 (A) Ducts in Unconditioned Spaces and (B) Standard Air Distribution System in Unconditioned Spaces Fig. 5 Entrance Fittings to Eliminate Unstable Airflow in Box Plenum Fig. 6 Dimensions for Efficient Box Plenum --- CHAPTER 11: STEAM SYSTEMS --- 1. Advantages 2. Fundamentals 3. Effects of Water , Air , and Gases 4. Heat Transfer 5. Basic Steam System Design 6. Steam Source Boilers Heat Recovery and Waste Heat Boilers Heat Exchangers 7. Boiler Connections Supply Piping Return Piping 8. Design Steam Pressure 9. Piping Supply Piping Design Considerations Terminal Equipment Piping Design Considerations Return Piping Design Considerations 10. Condensate Removal from Temperature-Regulated Equipment 11. Steam Traps Thermostatic Traps Mechanical Traps Kinetic Traps 12. Pressure-Reducing Valves Installation Valve Size Selection 13. Terminal Equipment Selection Natural Convection Units Forced-Convection Units 14. Convection Steam Heating One-Pipe Steam Heating Systems Two-Pipe Steam Heating Systems 15. Steam Distribution 16. Temperature Control 17. Heat Recovery Flash Steam Direct Heat Recovery 18. Combined Steam and Water Systems 19. Commissioning References Bibliography Tables Table 1 Properties of Saturated Steam Table 2 Pressure Differential Temperature Control Figures Fig. 1 Exhaust Heat Boiler Fig. 2 Typical Boiler Connections Fig. 3 Boiler with Gravity Return Fig. 4 Method of Dripping Steam Mains Fig. 5 Trap Discharging to Overhead Return Fig. 6 Trapping Strainers Fig. 7 Trapping Multiple Coils Fig. 8 Recommended Steam Trap Piping Fig. 9 Trapping Temperature-Regulated Coils Fig. 10 Steam Traps Fig. 11 Pressure-Reducing Valve Connections: Single-Stage Fig. 12 Two-Stage Pressure-Reducing Valve Fig. 13 One-Third/Two-Thirds Pressure-Reducing Valve Station Fig. 14 One-Pipe System Fig. 15 Two-Pipe System Fig. 16 Inlet Orifice Fig. 17 Orifice Capacities for Different Pressure Differentials Fig. 18 Flash Steam Fig. 19 Vertical Flash Tank Fig. 20 Flash Tank Diameters --- CHAPTER 12: DISTRICT HEATING AND COOLING --- Applicability Components Environmental Benefits 1. SYSTEM MASTER PLANNING 1.1 Economic Considerations Consumer Economics Producer Economics District Energy Economic Comparison 2. CENTRAL PLANT 2.1 Heating and Cooling Production Heating Medium Steam and Hot Water Generation Chilled-Water Generation Thermal Storage Auxiliaries 2.2 Chilled-Water Distribution Design Considerations Constant Flow Variable Flow Chilled-Water System Design Guidelines 3. DISTRIBUTION SYSTEM 3.1 Hydraulic Considerations Objectives of Hydraulic Design Water Hammer Pressure Losses Pipe Sizing Network Calculations Condensate Drainage and Return in Steam Systems 3.2 Thermal Considerations Thermal Design Conditions Thermal Properties of Pipe Insulation and Soil 3.3 Methods of Heat Transfer Analysis Calculation of Undisturbed Soil Temperatures Convective Heat Transfer at Ground Surface Uninsulated Buried Pipe Insulated Buried Pipe Buried Pipe in Conduit with Air Space Buried Pipe with Composite Insulation Two Pipes Buried in Common Conduit with Air Space Two Buried Pipes or Conduits Pipes in Buried Trenches or Tunnels Pipes in Shallow Trenches Buried Pipes with Other Geometries Pipes in Air Economical Thickness for Pipe Insulation 3.4 Expansion Provisions Pipe Supports, Guides, and Anchors 3.5 Distribution System Construction Tables Table 1 Summary of Economic Analysis Factors Table 2 Annual Utility Consumption Summary for Central Plant Alternatives Table 3 Estimates of Annual Maintenance and Utility Costsand Commercial Tower Costs Table 4 LLC Example of District Cooling Evaluation Table 5 Chiller Technology Table 6 Summary Table of Chiller Characteristics Table 7 Comparison of Commonly Used Insulations in Underground Piping Systems Table 8 Effect of Moisture on Underground Piping System Insulations Table 9 Soil Thermal Conductivities Table 10 Effect of Interior Insulation Thickness on Exterior Insulation Temperature (Example 6) Table 11 Effects of Soil Thermal Conductivity and Burial Depth on Exterior Insulation Temperature (Example 6) Table 12 Relative Merits of Piping Materials Commonly Used for District Cooling Distribution Systems Table 13 Relative Merits of Direct and Indirect Consumer Interconnection Table 14 Conversion Suitability of Heating System by Type Table 15 Measuring Points and Derivative Parametersfor Remote Monitoring and Control of Indirect Table 16 Flowmeter Characteristics Figures Fig. 1 Major Components of District Heating System Fig. 2 Master Planning Pyramid Fig. 3 Breakdown of Life-Cycle Cost by Components for Example 1 Fig. 4 Layout for Hot-Water/Chilled-Water Plant Fig. 5 Constant-Flow Primary Distribution with Secondary Pumping Fig. 6 Variable-Flow Primary/Secondary Systems Fig. 7 Uninsulated Buried Pipe Fig. 8 Insulated Buried Pipe with Air Space Fig. 9 Two Pipes Buried in Common Conduit with Air Space Fig. 10 Two Buried Pipes or Conduits Fig. 11 Pipes in Buried Trenches or Tunnels Fig. 12 Slide and Guide Detail Fig. 13 Relative Costs for Piping Alone, Uninsulated Fig. 14 Walk-Through Tunnel Fig. 15 Concrete Surface Trench Fig. 16 Deep-Bury Small Tunnel (Boxed Conduit) Fig. 17 Poured Insulation System Fig. 18 Field-Installed, Direct-Buried Rigid Closed-CellInsulation System Fig. 19 Conduit System Components Fig. 20 Corrosion Rate in Aggressive Environment Similar to Mild Steel Casings in Soil Fig. 21 Conduit System with Annular Air Space and Single Carrier Pipe Fig. 22 Conduit System with Two Carrier Pipes and Annular Air Space Fig. 23 Conduit System with Single Carrier Pipe and No Air Space (WSL) Fig. 24 Conduit Casing Temperature Versus Soil Thermal Conductivity Fig. 25 Direct Connection of Building System to District Chilled Water with Building Pumps Fig. 26 Direct Connection of Building System to District Chilled Water Without Building Pumps Fig. 27 Direct Connection of Building System to District Hot Water Fig. 28 Indirect Connection of Building System to District Chilled Water Fig. 29 Basic Cascading Indirect Heating-System Schematic Fig. 30 District/Building Interconnection with Heat Recovery Steam System Fig. 31 District/Building Interconnection with Heat Exchange Steam System Fig. 32 Plate Heat-Exchanger Performance with Constant Flow on Customer Side and Customer-Sid