ASHRAE Book GeothermalHeatingCooling 2014
$67.92
Geothermal Heating and Cooling: Design of Ground-Source Heat Pump Systems
| Published By | Publication Date | Number of Pages |
| ASHRAE | 2014 |
Geothermal Heating and Cooling is a complete revision of Ground-Source Heat Pumps: Design of Geothermal Systems for Commercial and Institutional Buildings, which is recognized as the primary reference for nonresidential ground-source heat pump (GSHP) installations. This new work takes advantage of the many lessons learned since the time of the original publication, when GSHPs were primarily residential applications. Many improvements have evolved, and performance data, both positive and negative, is now available to guide the development of best practices. This essential guide for HVAC design engineers, design-build contractors, GSHP subcontractors, and energy/construction managers also provides building owners and architects with insights into characteristics of quality engineering firms and the information that should be provided by design firms competing for GSHP projects. This revision draws on new ASHRAE and industry research in critical areas, as well as measured data from long-term installations and optimized installation practices used by high-production GSHP contractors. Nearly all chapters and appendices were completely rewritten, and they include coverage of closed-loop ground (ground-coupled), groundwater, and surface-water systems plus GSHP equipment and piping. Additional information on site characterization has been added, including a new hydrogeological chapter. Another new chapter contains results of recent field studies, energy and demand characteristics, and updated information to optimize GSHP system cost. While other publications deal primarily with ground-coupled heat pumps, this text includes detailed coverage of groundwater, surface-water, and GSHP costs. Tables, graphs, and equations are provided in both Inch-Pound (I-P) and International System (SI) units. As a bonus, supplemental Microsoft® Excel® macro-enabled spreadsheets for a variety of GSHP calculations accompany the text. Keywords: ground-source heat pumps, geothermal heat pumps, ground-coupled heat pumps, groundwater heat pumps, surface-water heat pumps, water-source heat pumps, pond-loop heat pumps, lake-water heat pumps
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 1 | Supporting Files Online Cover |
| 8 | TOC |
| 12 | Preface |
| 14 | Acknowledgments |
| 16 | Acronyms |
| 20 | Chapter 1 – Introduction to Ground-Source Heat Pumps 1.1 Overview, Nomenclature, and GSHP Types |
| 21 | Figure 1.1 Primary GSHP Equipment Options |
| 22 | 1.2 Ground-Coupled Heat Pumps Figure 1.2 Closed-Loop Ground-Coupled Heat Pump with Three Ground-Loop Options |
| 23 | 1.3 Groundwater Heat Pumps |
| 24 | Figure 1.3 Open-Loop Groundwater Heat Pump with Isolation Heat Exchanger 1.4 Surface-Water Heat Pumps |
| 25 | Figure 1.4 Closed-Loop Surface-Water Heat Pump with Two Lake Coil Options |
| 26 | 1.5 Exterior and Building Loop Piping Options 1.6 Field Study Results |
| 27 | Figure 1.5 Three Options for Closed-Loop Heat Pump Vertical Ground-Loop Circuits |
| 28 | Figure 1.6 Unitary-Loop GCHP with Each Heat Pump Connected to Individual Loops Figure 1.7 One-Pipe Loop GCHP with Reverse-Return Header Ground Loop |
| 29 | Figure 1.8 Common (Subcentral) Loop GCHP with Close Header Ground Loop Figure 1.9 Central Loop GCHP with Modified Reverse-Return Header Ground Loop |
| 30 | Figure 1.10 Central-Loop GWHP with Plate-Frame Isolation Heat Exchanger Figure 1.11 Central-Loop SWHP with Reverse-Return Header Lake Coils |
| 31 | 1.7 Preliminary Assessment, Design Steps, and Deliverables |
| 34 | 1.8 References |
| 36 | Chapter 2 – Equipment for Ground-Source Applications 2.1 Heat Pump Types |
| 37 | Figure 2.1 Vertical Water-to-Air Heat Pump for Ground-Source Applications Figure 2.2 Convenience Store Application with Heating and Cooling Requirements |
| 38 | Figure 2.3 Accessible Water-to-Air Heat Pump Equipment Room Installation |
| 39 | Figure 2.4 Water-to-Air Heat Pump on Mezzanine above School Hallway Figure 2.5 Water-to-Air Heat Pump with Internal Pump |
| 40 | Figure 2.6 Horizontal Water-to-Air Heat Pump in Gymnasium Figure 2.7 Classroom Water-to-Air Heat Pump with Internal Energy Recovery Unit |
| 41 | Figure 2.8 Water-to-Air Heat Pump Classroom Console Unit Figure 2.9 Bank of Eight Water-to-Water Heat Pumps |
| 42 | Figure 2.10 Classroom Unit (left) and with Panel Removed (right) |
| 43 | Figure 2.11 Technician Solution to Servicing Heat Pump with Limited Access Figure 2.12 Difficult-to-Service Heat Pump Location |
| 44 | Figure 2.13 Controls for Multiple-Capacity Water-to-Air Heat Pump 2.2 Water-Source Heat Pump Standards |
| 45 | Table 2.1 AHRI/ASHRAE ISO Standard 13256-1 Rating Conditions for Water-to-Air Heat Pumps (ASHRAE 2012a) Table 2.2 AHRI/ASHRAE ISO Standard 13256-2 Rating Conditions for Water-to-Water Heat Pumps (ASHRAE 2012b) |
| 46 | 2.3 Performance of Water-Source Heat Pumps |
| 48 | Table 2.3a Rated Capacity and Efficiency Values for Water-to-Air Heat Pumps—I-P Table 2.3b Rated Capacity and Efficiency Values for Water-to-Air Heat Pumps—SI |
| 49 | Table 2.4 Rated Capacity and Efficiency Values for Water-to-Water Heat Pumps |
| 50 | Table 2.5 Cooling Capacity and Input Power Correction Factors (CFs) for EATs* Table 2.6 Heating Capacity and Input Power Correction Factors (CFs) for EATs Table 2.7 Capacity and Input Power Correction Factors (CFs) for Airflow Rate |
| 51 | Figure 2.14 Cooling Capacity and Input Power Correction Factors for Liquid Flow Rate |
| 52 | Figure 2.15 Heating Capacity and Input Power Correction Factors for Liquid Flow Rate |
| 54 | Example 2.1— Heat Pump Performance Correction, Cooling Mode (I-P) |
| 55 | Example 2.2— Heat Pump Performance Correction, Heating Mode (SI) |
| 57 | 2.4 GSHP System Performance |
| 58 | Figure 2.16 Ten-Heat-Pump Common Loop—One of Twenty in Example |
| 59 | Figure 2.17 HVACsystemEff.xlsx Output—System Cooling Efficiency for Common-Loop GCHP System with 200 Heat Pumps |
| 60 | Figure 2.18 Chilled-Water VAV Vertical Ground-Loop System Figure 2.19 HVACsystemEff.xlsx Output—Component Specifications and System Efficiencies for Chilled-Water VAV GSHP |
| 61 | 2.5 Suggested GSHP Specifications 2.6 Outdoor Air and GSHPs Table 2.8 Recommended Minimum Allowable Heat Pump Efficiencies— Efficiency Values Based on Ratings According to AHRI/ASHRAE ISO Standards 13256-1 and 13256-2 (ASHRAE 2012a, 2012b) |
| 62 | Figure 2.20 Multizone Ventilation Air Delivery |
| 63 | Figure 2.21 DOAS for Ventilation Air Delivery |
| 64 | Table 2.9 Minimum Ventilation Rates in Breathing Zone—Abbreviated (Complete listing found in Table 6.2.2.1 of ASHRAE Standard 62.1-2013) |
| 66 | Table 2.10 Outdoor Indoor-Air Intake Flow Rates for 10-Zone Office—DOAS and Multizone |
| 67 | Figure 2.22 Energy Recovery Unit: An Effective GSHP Loop Reduction Device |
| 68 | Figure 2.23 Zone Ventilation Air Delivery Options and Issues with Unitary Heat Pumps 2.7 References |
| 70 | Chapter 3 – Fundamentals of Vertical Ground Heat Exchanger Design 3.1 Overview |
| 71 | 3.2 Equations for Required Ground Heat Exchanger Length |
| 73 | Figure 3.1 Schematic and Thermal Network for U-Tube Ground Heat Exchanger |
| 77 | Figure 3.2 Measured Increase in Average Loop Temperature Above Initial Ground Temperature 3.3 Borehole Thermal Resistance |
| 78 | Figure 3.3 Ground Heat Exchanger Moisture Migration and Evaporative Cooling Mechanisms Figure 3.4 Typical U-tube Installations for Unconsolidated and Consolidated Formations |
| 79 | Figure 3.5 Bore Resistance Shape Factors for U-Tube Locations in Vertical Boreholes |
| 81 | Table 3.1 Thermal Resistances of Bores with U-Tubes for Various Conditions |
| 82 | Table 3.2a Properties of Grouts, Fills, and Pipe Materials (Allan 1996; GPI 2014)—I-P |
| 83 | Table 3.2b Properties of Borehole Grouts and Fills (Allan 1996; GPI 2014)—SI |
| 85 | Table 3.3 Reynolds Numbers in DR 11 HDPE Pipe for Various Pipe Diameters and Flow Rates Example 3.1— Calculation of Bore THermal Resistance |
| 86 | 3.4 Ground Thermal Resistance and Basic Heat Exchanger Design |
| 87 | Figure 3.6 Fourier/G-Factor Graph for Ground Thermal Resistance (Ingersoll et al. 1954) |
| 88 | Figure 3.7 Short-Circuit Factor (Fsc) for Standard and Shallow Bore U-Tube Applications (Kavanaugh 1984) Example 3.2— Vertical Ground Heat Exchanger Design—I-P |
| 90 | Example 3.3— Vertical Ground Heat Exchanger Design—SI |
| 92 | 3.5 GCHP Site Assessment: Ground Thermal Properties |
| 93 | Table 3.4 Thermal Conductivity (k) and Diffusivity (a) of Sand and Clay Soils— Values Indicate Ranges Predicted by Five Independent Methods (Farouki 1982) |
| 94 | Table 3.5 Ranges of Thermal Properties of Rocks at 77°F (25°C) (Toulokian et al. 1981; Robertson 1988; Carmichael 1989) |
| 95 | Figure 3.8 Groundwater Temperature (°F) Profiles for One State (Chandler 1987) 3.6 GCHP Site Evaluation: Thermal Property Tests |
| 96 | Figure 3.9 Approximate Groundwater Temperatures (°F) in the USA (Collins 1925) Figure 3.10 Formation Thermal Properties Test Apparatus (ASHRAE 2011) |
| 99 | Figure 3.11 Average Loop Temperature Data for 300 ft (91 m) Test Bore Figure 3.12 Average Loop Temperature Data vs Natural Log of Time—Hours 8 to 44 |
| 100 | Example 3.4— Estimation of Thermal Diffusivity 3.7 Long-Term Ground Temperature Change |
| 103 | Figure 3.13 Chart and Equation for Determining I(X) (Ingersoll et al. 1954) Example 3.5— Temperature Penalty Calculation |
| 104 | Figure 3.14 Representative Earth Cylinders for Heat Storage |
| 107 | Table 3.6 Twenty-Year Temperature Change for 10 x 10* Vertical Bore Ground Heat Exchanger for Moisture Recharge Estimates, EFLH Ratio, and Building Loads |
| 108 | 3.8 Comments on the Design of Vertical Ground Heat Exchangers 3.9 References |
| 110 | Chapter 4 – Applied Ground-Coupled Heat Pump System Design 4.1 System Design Overview |
| 112 | Figure 4.1 Eight-Zone Office Building in St. Louis, Missouri 4.2 Applied Design Procedure for Vertical GCHPs (Steps 1–10) |
| 114 | Table 4.1 Results of Initial Cooling Load and Heat Loss Calculation for Example Building |
| 115 | Table 4.2 Results of Revised Cooling Load and Heat Loss Calculation for Example Building |
| 116 | Table 4.3 Results of Monthly Part-Load Factor (PLF) Calculation for Example Building (Occupied 5 Days/Week) Table 4.4 Comparison of Total Heat Losses to Net Heat Losses for Example Building |
| 118 | Table 4.5 Equivalent Full-Load Cooling and Heating Hours (Carlson 2001) |
| 121 | Figure 4.2 Capacity Correction for Fan Heat Based on 400 cfm/ton (54 L/s·kW) for Unitary Heat Pumps with Permanent Split Capacitor and Electrically Commutated Motors and Forward- and Backward-Curved Blades Figure 4.3 Fan Power Addition Based on 400 cfm/ton (54 L/s·kW) for Unitary Heat Pumps with Permanent Split Capacitor and Electronically Commutated Motors and Forward- and Backward-Curved Blades |
| 123 | Table 4.6 Heat Pump Performance Corrected for Air Temperatures, Fan Power, and Pump Power |
| 124 | Table 4.7 Zone Cooling and Heating Requirements with Heat Pumps and Specifications |
| 126 | Figure 4.4 Initial Design for Ground-Loop Circuit Arrangement |
| 129 | 4.3 Evaluate Alternative Designs (Step 11) |
| 130 | Figure 4.5 Final Design for Common Ground-Loop Circuit Arrangement |
| 131 | Figure 4.6 Unitary-Loop System |
| 132 | Figure 4.7 One-Pipe Loop System |
| 133 | Figure 4.8 Central Ground Loop, Building Loop, and Pumps |
| 136 | Figure 4.9 Hybrid Fluid Cooler—GSHP System |
| 139 | Figure 4.10 Hybrid System with Boiler Connected to Ground Loop |
| 140 | Table 4.8 Impact of Design Alternatives Original Design: System EER = 13.9, COP = 4.0, ELT(clg) = 86°F (30°C), ELT(htg) = 50°F (10°C), 19 vertical bores at 4800 ft (1460 m) total, 1 in. (32 mm) nominal HDPE U-tubes, 20 ft (6 m) bore separation, two ground-loop circuits (10 bore and 9 b… 4.4 Performance Verification and Necessary Documents |
| 141 | 4.5 References |
| 144 | Chapter 5 – Surface-Water Heat Pumps 5.1 Introduction |
| 145 | Figure 5.1 Closed-Loop Surface-Water Heat Pump System with HDPE and Plate SWHEs |
| 146 | Figure 5.2 Open-Loop System for Cooling-Only or Modest Heating Applications |
| 147 | 5.2 Heat Transfer in Reservoirs Figure 5.3 Reservoir Heat Transfer Modes |
| 149 | Example 5.1— Determining Surface-Water Evaporation and Heat Transfer Rates |
| 151 | 5.3 Thermal Patterns in Reservoirs and Streams |
| 152 | Figure 5.4 Reservoir Depth vs Temperature for Four Seasons |
| 154 | Figure 5.5 Temperature Profiles for a Deep Lake in North Alabama (Peirce 1964) Figure 5.6 River Temperature Profiles in Central Alabama (Peirce 1964) |
| 155 | Figure 5.7 Shallow Lake Temperature Profiles in Central Alabama (Peirce 1964) |
| 156 | Figure 5.8 Deep Lake Temperatures in Temperate Climate (Hattemer and Kavanaugh 2005) |
| 157 | Figure 5.9 High-Flow Reservoir Temperatures in Tennessee (Hattemer and Kavanaugh 2005) Figure 5.10 Deep Lake Temperatures in Minnesota (Hattemer and Kavanaugh 2005) |
| 158 | 5.4 Fundamentals of Closed-Loop Surface-Water Heat Exchangers Figure 5.11 Shallow Lake Temperatures in Minnesota (Hattemer and Kavanaugh 2005) |
| 159 | Figure 5.12 Thermal Resistance per Unit Length for Single SWHE Coil |
| 162 | Table 5.1 Thermal Properties of HDPE Pipe (PPI 2014) |
| 163 | 5.5 Closed-Loop Surface-Water Heat Exchangers |
| 164 | Table 5.2 Properties of Water (Holman 1986) Table 5.3 Approximate Fouling Factors* for SWHE Coils |
| 165 | Table 5.4 Cooling-Mode Resistances of Clean SWHEs with Turbulent Flow (Hansen 2011) |
| 166 | Figure 5.13 Slinky Coil Test Arrangement (Hattemer, 2005) Figure 5.14 Test Arrangement of Bundled Coils with Spacers |
| 167 | Figure 5.15 Suggested Cold-Reservoir SWHE Location |
| 168 | Figure 5.16 Cooling-Mode Design Lengths for HDPE SWHEs (I-P Units) Figure 5.17 Cooling-Mode Design Lengths for HDPE SWHEs (SI Units) |
| 169 | Figure 5.18 Heating-Mode Design Lengths for HDPE SWHEs (I-P Units) Figure 5.19 Heating-Mode Design Lengths for HDPE SWHEs (SI Units) |
| 170 | Example 5.2— Cooling-Mode SWHE Design |
| 172 | Figure 5.20 Manufacturer’s Cooling-Mode Design Results for Flat-Plate SWHEs (AWEB 2014) |
| 173 | 5.6 Circuits and Layout of Surface-Water Heat Exchangers Figure 5.21 Manufacturer’s Heating-Mode Design Results for Flat-Plate SWHEs (AWEB 2014) |
| 174 | Figure 5.22 HDPE Bundle Coil SWHEs with Spacers Figure 5.23 Slinky Coil SWHEs Delivered to Site in Shipping Bundles |
| 175 | Figure 5.24 Slinky Coil SWHEs Being Floated In Place Figure 5.25 Nominal 50 ton (175 kW) Flat-Plate SWHE (AWEB 2014) |
| 176 | Figure 5.26 Flat-Plate SWHE with Deflector for River Application (AWEB 2014) Figure 5.27 Nominal 24 ton (84 kW) SWHE Installed Before Lake is Filled (AWEB 2014) |
| 177 | Table 5.5a Head Losses and Reynolds Numbers for SWHE Coils with Antifreeze Solutions at 32°F (CRC 1970; Dow 1990) Example 5.3— SWHE Circuit Design with Heating Mode Dominant |
| 178 | Table 5.5b Head Losses and Reynolds Numbers for SWHE Coils with Antifreeze Solutions at 0°C (CRC 1970; Dow 1990) |
| 179 | Example 5.4— SWHE Circuit Design with Cooling Mode Critical Figure 5.28 SWHP System: 20 Ton (70 kW) Cooling Load and 10 Ton (35 kW) Heat Loss |
| 180 | Figure 5.29 E-PipeAlator14.xlsm Head Loss Results for SWHP System with 20 Ton (70 kW) Cooling Requirement |
| 181 | Figure 5.30 E-PipeAlator14.xlsm Head Loss Results for SWHP System with 10 Ton (35 kW) Heat Loss 5.7 Open-Loop Surface-Water Heat Pump Systems |
| 182 | Figure 5.31 Open-Loop Surface-Water Cooling System (with Heating for 42°F+ [6°C+] Lakes |
| 183 | 5.8 Direct Cooling and Precooling with Surface-Water Systems |
| 184 | Figure 5.32 Air Coil Arrangement for Surface-Water or Groundwater Direct Cooling Systems |
| 185 | Figure 5.33 Schematic Arrangement of Direct/Precooling Water Coil and Heat Pump Figure 5.34 Total and Sensible Capacities of Four-Row Chilled-Water Coil |
| 186 | Example 5.5— Air Coil Design for Reservoir Free Cooling |
| 188 | 5.9 Heat Transfer in GSHP Headers |
| 189 | Table 5.6 Coefficients for Reservoir and Ground Header Heat Transfer |
| 190 | Figure 5.35 Ground Temperature Variation from Local Mean for Damp, Medium-Density Soil Example 5.6— Calculation of Reservoir and Ground Header Temperature Rise |
| 191 | Example 5.7— Short-Circuit Heat Transfer in Horizontal Headers |
| 192 | 5.10 Environmental Impact of Surface-Water Heat Pumps |
| 193 | Figure 5.36 Comparative Reservoir Heat Rates for a SWHP and a Mid-Size Boat Motor |
| 195 | 5.11 Recommendations for the Design of Surface-Water Heat Pumps |
| 196 | 5.12 References |
| 198 | Chapter 6 – Piping and Pumps for Closed-Loop Ground-Source Heat Pumps 6.1 Overview of GCHP and SWHP Piping Systems and Pumps |
| 199 | Figure 6.1 HDPE U-Tube Loop Field and Surface-Water Loop Installations |
| 200 | Figure 6.2 Equipment-Room Polypropylene Piping Figure 6.3 Reverse-Return Ground-Loop Circuit with Reduced Header Sections |
| 201 | 6.2 Impact of Pump Power Figure 6.4 Why Some GSHPs Use More Energy than Advertised |
| 202 | Figure 6.5 System EER and COP Results for 5 Ton (18 kW) Heat Pump with Two Pumps Example 6.1— Unitary Loop System Design |
| 203 | Table 6.1 Head Loss Calculation for Original Design: Two 385 W Pumps Required Figure 6.6 System EER and COP Results for 5 Ton (18 kW) Heat Pump with One Smaller Pump |
| 204 | Table 6.2 GSHP System Pump Power Benchmarks 6.3 Impact of Pump Energy |
| 205 | Table 6.3 Energy Consumption and Cost for Example St. Louis Office* |
| 206 | Figure 6.7 Load Profiles for St. Louis Office Building Figure 6.8 Three Pump and Piping Options for Cost Comparison |
| 207 | Table 6.4 On-Off, Constant-Speed, and Variable-Speed Pump Energy/Cost—Optimized Pump Size Table 6.5 On-Off, Constant-Speed, and Variable-Speed Pump Energy/Cost—50% Larger Pump |
| 208 | 6.4 Piping Fundamentals |
| 209 | 6.5 Pipe Materials, Dimensions, and Loss Characteristics |
| 211 | Table 6.6 Dimensions for Iron, HDPE, Copper, and PEX Pipe and Tubing—I-P Table 6.7 Dimensions for Schedule and Standard Dimension Ratio Pipe—SI |
| 213 | Table 6.8 DR 11 HDPE Head Loss—Feet of Water/100 Linear Feet at 60°F*—I-P Table 6.9 DR 11 HDPE Pressure Loss—kPa/100 Linear Metres at 20°C*—SI |
| 214 | Table 6.10 Maximum Flow Rates for Optimum Head/Pressure Losses in GSHP Systems |
| 215 | Table 6.11 Equivalent Lengths (Leqv) for HDPE Pipe Fittings |
| 216 | Table 6.12 Equivalent Lengths (Leqv) for Iron and Copper Pipe Fittings (Kavanaugh 2006) Table 6.13 Typical Flow Coefficients (Cv) for Valves and Fittings (Cv = Flow in gpm for Dp = 1.0 psi, Dh = 2.31 ft of water) |
| 217 | 6.6 Pump Fundamentals |
| 218 | Figure 6.9 Common Pump Types Uses for Closed-Loop GSHP Applications |
| 219 | Table 6.14 Minimum Motor Full-Load Efficiencies (NEMA 2009) and Part-Load Multipliers Example 6.2— Calculation of Pump Motor Electrical Input Power |
| 220 | Figure 6.10 Pump Curves: Flow vs Head, Efficiency, and Power for Three Impeller Diameters 6.7 Closed-Loop Water Distribution System Design Procedure |
| 222 | Figure 6.11 Layout of Example Pipe Network with Flow Rates for Each Section |
| 224 | Table 6.15 Head Loss Summary Table for GSHP Closed-Loop Piping Network Example—I-P |
| 226 | Figure 6.12 Pump Curve for Large Impeller, Showing System Curve and Operating Point |
| 227 | 6.8 Pump Control and Heat Pump Connections Figure 6.13 Unitary-Loop Heat Pump Connections and Pump Control |
| 229 | Figure 6.14 Heat Pump Connections with Check Valve for Common Loop |
| 230 | Figure 6.15 One-Pipe Loop Heat Pump Connections and Control Method Figure 6.16 One-Pipe System Heat Pump, Circulator Pump, and Hose Connections |
| 231 | Figure 6.17 Main Pumps for One-Pipe GCHP System Figure 6.18 Central-Loop Heat Pump Connections and VSD Control Option |
| 232 | Figure 6.19 Single-Story Southeast Texas High School |
| 233 | 6.9 Ground-Loop Piping Circuits Figure 6.20 Unitary Ground-Loop Header |
| 234 | Figure 6.21 Modified Reverse-Return Ground-Loop Header |
| 235 | Figure 6.22 Ready-to-Ship Headers with Sidewall Take-Offs Fabricated in Controlled Conditions Figure 6.23 Close Headers for Ground Loops Beneath Pavement (Parking Lots) |
| 236 | Figure 6.24 Standard Reverse-Return Ground-Loop Header with Below-Grade Circuit Valves |
| 237 | Figure 6.25 Two Equipment-Room Ground-Loop Circuit Manifolds |
| 238 | Figure 6.26 Below-Grade Valve Vault with 20 Circuits and 200 U-Tubes |
| 239 | Figure 6.27 Rig to Straighten (“Tame”) Coiled HDPE |
| 240 | Figure 6.28 Purge Pump for 10 to 25 ton (35 to 90 kW) Circuits Figure 6.29 Portable Truck-Mount Purge Pump for 10 to 25 ton (35 to 90 kW) Circuits |
| 241 | Figure 6.30 Debris Removed with Purge Pump on 300 ton (1050 kW) Ground Loop Figure 6.31 Skid-Mounted Purge Pump for Flushing Ground Loops without Circuits |
| 242 | 6.10 Summary of Piping and Pump Design Guidelines |
| 243 | 6.11 References |
| 244 | Chapter 7 – Hydrology, Water Wells, and Site Evaluation 7.1 Groundwater Hydrology |
| 245 | Figure 7.1 Aquifer Types—Confined (Water Table) and Unconfined (Artesian) |
| 246 | Table 7.1 Mean Permeability Values |
| 247 | Figure 7.2 Transmissivity, Permeability, and Hydraulic Gradient |
| 248 | Figure 7.3 Method for Determination of Groundwater Flow Direction |
| 249 | 7.2 Water Well Terminology Figure 7.4 Production-Well Terminology |
| 250 | Figure 7.5 Confined and Unconfined Well Responses to Pumping |
| 251 | Figure 7.6 Injection-Well Terminology |
| 252 | 7.3 Common Water Well Completion Variations |
| 253 | Figure 7.7 Open-Hole Well Completion |
| 254 | Figure 7.8 Naturally Developed Well Completion |
| 255 | Figure 7.9 Gravel Pack Well Completion 7.4 Selected Topics in Water Well Construction and Design |
| 256 | Table 7.2 Water Well Specification Subheadings |
| 257 | Table 7.3 Well Casing Diameter Guidelines |
| 258 | Figure 7.10 Sieve Analysis Results Example 7.1— Screen Slot Size Selection |
| 260 | Example 7.2— Predicting Injection Pressure Requirements |
| 262 | 7.5 Site Evaluation for GWHP Systems |
| 264 | Table 7.4 Site Evaluation Issues |
| 265 | Figure 7.11a Water Well Completion Report Example #1 |
| 266 | Figure 7.11b Lith-Log Portion of Water Well Completion Report Example #1 |
| 267 | Figure 7.12 Water Well Completion Report Example #2 |
| 271 | Figure 7.13 Well Flow Test with Water Flow Measurement via Orifice Plate and Ultrasonic Flowmeter |
| 272 | Figure 7.14 Flow Test Water Level Measurement Techniques: Downhole Pressure Transducer Connected to Data Logger (Upper Left), Manual Water Level Measurement with Electric Sounder (Center), and Gate Valve for Water Flow Control Table 7.5 Well Test Data Example |
| 274 | Table 7.6 Minimum Water Quality Analysis Components |
| 276 | Table 7.7 Interpretation of the Ryznar Stability Index (Carrier Corp 1965) Table 7.8 Interpretation of the Langlier Saturation Index (Carrier Corp 1965) |
| 277 | Example 7.3— Evaluating Scaling PotentiaL |
| 279 | Table 7.9 Hardness Classification |
| 280 | 7.6 References |
| 282 | Chapter 8 – Groundwater Heat Pump System Design 8.1 Introduction |
| 283 | Figure 8.1 GWHP and GCHP Relative Ground-Loop Costs (Rafferty 2008) |
| 284 | Table 8.1 Approximate Heat Pump EWTs for GWHP Systems |
| 286 | Figure 8.2 GWHP System Design Variants |
| 287 | 8.2 General Design Approach Figure 8.3 Heat Pump Performance vs Groundwater Flow |
| 288 | Figure 8.4 Well Pumping Power Requirement Figure 8.5 System Power Requirement vs Groundwater Flow |
| 290 | Figure 8.6 Example Optimum Groundwater Flow Rates, (a) I-P and (b) SI |
| 291 | Figure 8.7 System Performance Evaluation Steps |
| 293 | 8.3 Production/Injection Well Separation |
| 294 | Table 8.2 Minimum Production/Injection Well Spacing Example 8.1— Well Spacing |
| 295 | 8.4 Building Loop Pumping for GWHP 8.5 Well Pumps |
| 296 | Figure 8.8 Submersible Well Pump Assembly |
| 297 | Figure 8.9 Submersible Pump Cooling Shroud |
| 298 | Figure 8.10 Well Pump Curve Example 8.2— PUMP selection |
| 302 | Figure 8.11 Injection Line Pressure vs Injection-Well Pressure |
| 303 | Table 8.3 Motor Efficiency—Submersible and Conventional Motors Table 8.4 Well Pump Efficiency (Nominal 3600 rpm) |
| 304 | Table 8.5 Example Well Pump Head Values—Configuration 2 Table 8.6 Example Well Pumping Values—Configuration 3 |
| 305 | Table 8.7 Pumping Values—Injection Pressure Control with Configuration 4 |
| 306 | Table 8.8 Constant-Speed Submersible Motor Cycling Data (Franklin 2007) |
| 307 | Example 8.3— Setpoint Selection |
| 308 | Table 8.9 Dual Setpoint Well Pump Control Temperature Range Requirements Table 8.10 Submersible Motor Variable-Frequency Drive Cautions (Franklin 2007) |
| 310 | 8.6 Heat Exchangers Figure 8.12 Plate Heat Exchanger |
| 311 | Figure 8.13 Plate Heat Exchanger Serving 115 ton (405 kW) School System |
| 312 | Table 8.11 Impact of Heat Exchanger Approach |
| 313 | Table 8.12 Stainless Steel Chloride Thresholds |
| 314 | Figure 8.14 Alternative Heat Exchanger Configurations |
| 315 | 8.7 System Design Example |
| 316 | Table 8.13 Design Example Well Information Table 8.14 Design Example Well Flow Test Information |
| 317 | Table 8.15 Design Example Water Chemistry |
| 322 | Table 8.16 Design Example Cooling-Mode Performance |
| 324 | Figure 8.15 Design Example—Cooling Mode Values |
| 326 | Table 8.17 Design Example Heating-Mode Performance |
| 329 | Figure 8.16 Suggested Instrumentation and Monitoring for a GWHP System Table 8.18 Strainer Screen Mesh Data |
| 330 | 8.8 GWHP Economics |
| 331 | Figure 8.17 Open-Loop Component Costs—212 ton (746 kW) System |
| 332 | Table 8.19 Heat Exchanger Costs |
| 333 | Table 8.20 Summary of Costs Included in Figures 8.18 to 8.20 |
| 334 | Figure 8.18 GWHP and GCHP Ground-Loop Costs—150 ft (46 m) Wells Figure 8.19 GWHP and GCHP Ground-Loop Costs—300 ft (90 m) Wells |
| 335 | Figure 8.20 GWHP and GCHP Ground-Loop Costs—700 ft (213 m) Wells |
| 337 | 8.9 References |
| 340 | Chapter 9 – GSHP Performance and Installation Cost 9.1 Field Study Performance Results |
| 341 | Figure 9.1 ENERGY STAR Ratings and Years of GSHP Operation for Commercial Buildings |
| 342 | Figure 9.2 ENERGY STAR Ratings of Central-Loop GSHPs with Central Pumps |
| 343 | Figure 9.3 ENERGY STAR Ratings of One-Pipe, Unitary, and Common-Loop GSHPs |
| 344 | Figure 9.4 ENERGY STAR Rating vs Bore Length Normalized to 63°F (17°C) Ground Temperature |
| 345 | Figure 9.5 ENERGY STAR Rating vs Installed Ventilation Air Equipment Capacity |
| 346 | Figure 9.6 ENERGY STAR Rating and HVAC Control Type |
| 347 | Figure 9.7 Measured Energy Consumption by Cooling System Type and EMCS Figure 9.8 Annual Site Energy Consumption and ENERGY STAR Ratings for GSHP Buildings |
| 348 | Figure 9.9 Hot-Day Loop Temperatures and VSD Speeds for 85,000 ft2 (7900 m2) Georgia School |
| 349 | Figure 9.10 Hot-Day Loop Temperatures for 78,000 ft2 (7200 m2) Florida Apartment Complex |
| 350 | Figure 9.11 Hot-Day Loop Temperatures for 37,000 ft2 (3400 m2) Northwest Tennessee Office Figure 9.12 Cold-Day Loop Temperatures for 37,400 ft2 (3450 m2) Elementary School |
| 351 | Figure 9.13 Maximum Average Ground Loop to Ground Approach Temperatures vs GSHP Age |
| 352 | 9.2 Prediction of the Performance of GSHP Design Options |
| 353 | Figure 9.14 Actual and Predicted Energy Use of 78,600 ft2 (7550 m2) Office Building |
| 354 | Table 9.1 Equipment Schedule for LEED Platinum GSHP Office Building |
| 355 | Figure 9.15 System Cooling Efficiency of Chilled-Water VAV GSHP with UFAD |
| 356 | Figure 9.16 Late-Winter Temperatures for Office Building with VAV UFAD GSHP Table 9.2 GSHP Equipment Schedule for Example 10,000 ft2 (929 m2) Office Building |
| 357 | Figure 9.17 System Cooling Efficiency for Unitary GSHP in Example Building 9.3 Field Study Installation Cost Results |
| 358 | Figure 9.18 System Heating Efficiency for Unitary GSHP in Example Building |
| 359 | Figure 9.19 GSHP System and Ground-Loop Cost Based on Building Floor Area |
| 360 | Figure 9.20 GSHP System and Ground-Loop Cost Based on Cooling Capacity Figure 9.21 Ground-Loop Cost Based on Vertical Bore Length |
| 361 | Figure 9.22 Previous GSHP System and Loop Cost Studies (Caneta Research 1995; Zimmerman 2000) |
| 362 | Table 9.3 Specification and Cost Details for Illinois Elementary School One-Pipe Loop GSHPs |
| 363 | Table 9.4 Itemized Component Retrofit Costs for Illinois Elementary School, 55,150 ft2 (5125 m2) with One-Pipe GSHP Table 9.5 Specification and Cost Details for Central Texas Unitary-Loop GSHPs |
| 364 | Table 9.6 Cost Details for ASHRAE RP-863 Study (Caneta 1995) |
| 365 | Table 9.7 Itemized Cost per Unit Floor Area for EPRI/TVA Study (Zimmerman 2000) |
| 366 | 9.4 Estimation of the Cost of GSHP Design Options |
| 367 | Table 9.8 HVAC Equipment Installation Costs (Material, Labor, and Profit) (RSMeans 2014) |
| 368 | Table 9.9 Heat Pump Online Catalog Prices (IWA 2014) Example 9.1— GSHP Equipment Cost |
| 369 | Table 9.10 GSHP Equipment Cost: Common-Loop Heat Pump vs Chilled-Water VAV |
| 370 | Table 9.11 Interior Pipe and Fitting Installation Costs (Material, Labor, and Profit) (RSMeans 2014) |
| 371 | Table 9.12 Ground-Loop Header Installation Costs (Material, Labor, and Profit) (RSMeans 2014) Figure 9.23 Underground Valve Vault Costs (TCI 2011) |
| 372 | Example 9.2— To Vault or Not to Vault |
| 373 | Table 9.13 Costs of Ground-Loop Manifold and Valves in Vault vs Equipment Room |
| 374 | Figure 9.24 Vertical Ground-Loop Cost Calculator with Grout Conductivity Comparison |
| 375 | 9.5 Characteristics of Quality GSHPs |
| 377 | 9.6 References |
| 378 | Appendix A – Conversion Factors |
| 379 | Figure A.1 HVAC and GSHP Units Converter (UnitsConverter.xlsx) |
| 380 | Appendix B – Standards and Recommendations for GSHP Components and Procedures |
| 382 | Appendix C – Pressure Ratings and Collapse Depths for Thermoplastic Pipe C.1 High-Density Polyethylene Pipe Pressure Ratings C.2 Fiberglass-Core Polypropylene Pipe Pressure Ratings C.3 HDPE Pipe Collapse Depths |
| 383 | Table C.1 Pressure Ratings for HDPE PE 4710 Pipe Table C.2 Pressure Ratings for HDPE PE 3406/3408 Pipe |
| 384 | Table C.3 Pressure Ratings* for Fiber-Core Polypropylene Pipe Table C.4 Apparent HDPE Elastic Modulus at 73.4°F (23°C) (PPI 2011) |
| 385 | Example C.1— Calculation of Pipe Buckling Depth |
| 386 | C.4 References |
| 388 | Appendix D – Vertical-Loop Installation Equipment and Procedures D.1 Vertical-Loop Drilling Methods |
| 389 | Figure D.1 Small Rotary Drilling Rig for Vertical-Loop Installation D.2 Vertical-Loop Installation D.3 Vertical-Loop Backfill and Grouting |
| 390 | Figure D.2 Completed U-Tube Heat Exchangers Figure D.3 “Lazy Susan” Cart for Handling U-Tube Coils at Construction Site |
| 391 | Figure D.4 Backfill/Grouting the Borehole Annulus Figure D.5 Grout Mixer and Pump |
| 392 | Table D.1 Grout Volumes Required to Fill U-Tube Bores (0% Waste) D.4 References |
| 394 | Appendix E – Example of Field Study Results E.1 County Water Agency Operations and Maintenance Office |
| 395 | Figure E.1 Ground-Loop Headers Figure E.2 Three Primary Pumps |
| 396 | Figure E.3 Office Building Ground-Loop Temperatures on a Warm Day |
| 398 | Appendix F – Properties of Antifreeze Solutions Table F.1 Properties of Antifreeze Solutions |
| 400 | Appendix G – Volumes of Liquids in Pipe Table G.1a Gallons of Liquid per 100 Linear Feet of Pipe |
| 401 | Table G.1b Litres of Liquid per 100 Linear Metres of Pipe |
| 402 | Appendix H – High-Density Polyethylene and Polypropylene Pipe Fusion Methods |
| 403 | Figure H.1 Socket Fusion Procedure |
| 404 | Figure H.2 HDPE Butt Fusion Procedure |
| 405 | Figure H.3 Electrofusion Procedure |
| 406 | Appendix I – Determination and Impact of Ground Coil Flow Imbalance I.1 Flow Imbalance in Closed-Loop GSHPs |
| 407 | Figure I.1 Flow Imbalance and Heat Transfer Impact Example I.2 References |
| 408 | Appendix J – Grain Size Classification Table J.1 Gran Size Classification |
| 410 | Appendix K – Well Drilling Methods K.1 Cable Tool Drilling |
| 411 | Figure K.1 Cable Tool Drilling Rig K.2 Conventional Rotary Drilling |
| 412 | Figure K.2 Rotary Drilling Rig |
| 413 | Figure K.3 Rotary Drilling Rig—Top Drive |
| 414 | Figure K.4 Rotary Drilling Rig—Mud System K.3 Air Rotary Drilling |
| 415 | Figure K.5 Air Rotary Drilling Rig—Side View |
| 416 | Figure K.6 Air Rotary Rig—Rear View K.4 Air Hammer Drilling |
| 417 | Table K.1 Drilling Method Performance Comparison (Adapted from Driscoll 1986) K.5 Drilling Method Effectiveness K.6 Reference |
| 418 | Appendix L – Well Flow Test and Water Chemistry Analysis Specification |
| 422 | Appendix M – Example Well Chemical and Biological Analysis Results M.1 Example |
| 424 | M.2 Reference |
| 426 | Appendix N – Well Problems and Strategies to Avoid Them N.1 Understanding Well Problems |
| 429 | N.2 References |
| 430 | Appendix O – Heat Exchanger Temperature Prediction Spreadsheet O.1 Spreadsheet tool |
| 431 | Figure O.1 Heat Exchanger Temperature Prediction Spreadsheet Input Section Figure O.2 Heat Exchanger Temperature Prediction Spreadsheet Output Section |
| 432 | Table O.1 Equations in Heat Exchanger Temperature Prediction Spreadsheet |
| 433 | O.2 Reference |
