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Question 1. Which heat‑transfer mode is the primary mechanism for energy exchange between a ground‑source heat pump’s refrigerant and the circulating fluid in the ground heat exchanger? A) Conduction B) Convection C) Radiation D) Phase change Answer: A Explanation: Heat moves from the refrigerant to the fluid (or vice‑versa) through the pipe wall by conduction; convection occurs in the fluid but the inter‑material transfer is conductive. Question 2. In a vapor‑compression cycle used in geothermal heat pumps, the component that removes heat from the refrigerant after compression is the: A) Evaporator B) Condenser C) Expansion valve D) Compressor Answer: B Explanation: After compression, the high‑pressure refrigerant releases heat to the secondary fluid in the condenser (the heat‑rejection side of the cycle). Question 3. Which of the following best distinguishes a ground‑source heat pump (GSHP) from a conventional air‑source heat pump? A) GSHP uses a refrigerant loop that never contacts the ground. B) GSHP extracts heat from the earth where temperature is relatively constant. C) GSHP requires no circulating pump.
D) GSHP can only provide cooling, not heating. Answer: B Explanation: GSHPs exploit the stable underground temperature, unlike air‑source units that depend on ambient air conditions. Question 4. A closed‑loop vertical borehole heat exchanger (BHE) typically consists of: A) A single pipe with flowing water only. B) Two concentric polyethylene pipes with a heat‑transfer fluid circulating. C) An open well that pumps groundwater directly through the heat pump. D) A pond‑filled pipe network. Answer: B Explanation: Vertical BHEs usually use a U‑tube (inner and outer pipe) to create a closed fluid circuit. Question 5. Which configuration is an example of an open‑loop geothermal system? A) Horizontal slinky loops buried in a field. B) A vertical borehole with a closed‑loop U‑tube. C) A well that pumps groundwater to the heat pump and then discharges it to a recharge well. D) A pond loop with a heat‑exchange coil submerged. Answer: C Explanation: Open‑loop systems draw water from a well, circulate it through the heat pump, and return it to a recharge source.
D) Ambient air temperature Answer: B Explanation: TRT yields the effective thermal conductivity of the ground and the borehole thermal resistance, both essential for sizing. Question 9. Which of the following is NOT a typical consideration when reviewing a plot plan for geothermal installation? A) Location of existing septic tanks B) Proximity to underground utilities C) Height of nearby telephone poles D) Property easements Answer: C Explanation: Telephone pole height is irrelevant to subsurface loop installation, whereas the other items affect placement and safety. Question 10. According to ACCA Manual J, the peak heating load for a residence is primarily determined by: A) The size of the garage. B) The building envelope’s U‑values and infiltration rate. C) The number of occupants. D) The color of exterior paint. Answer: B Explanation: Manual J calculates heating load based on heat loss through walls, windows, roof, and infiltration.
Question 11. Which software feature is most useful for integrating hourly building loads with ground loop design? A) 3‑D rendering of the house exterior. B) Hourly temperature and load profiling. C) Automatic generation of construction drawings. D) Real‑time weather forecasting. Answer: B Explanation: Hourly load profiles allow accurate matching of loop capacity to varying heating/cooling demands. Question 12. Unbalanced heating and cooling loads in a geothermal system can cause: A) Immediate system shutdown. B) Long‑term drift of ground temperature, reducing efficiency. C) Increase in refrigerant pressure beyond safe limits. D) No effect; the ground temperature remains constant. Answer: B Explanation: If heating exceeds cooling over time, the surrounding ground can warm, lowering the system’s coefficient of performance. Question 13. In borehole design, increasing the spacing between adjacent boreholes generally: A) Increases borehole thermal resistance. B) Decreases thermal interference, improving overall system performance. C) Reduces the total number of boreholes needed.
Question 16. For a closed‑loop system using HDPE pipe, the preferred method of joining pipe sections is: A) Solvent welding B) Butt fusion C) Threaded fittings D) Soldering Answer: B Explanation: Butt fusion creates a continuous, leak‑free HDPE joint suitable for geothermal loops. Question 17. When selecting an antifreeze solution for the loop fluid, a key design consideration is: A) The solution’s color. B) Its freezing point depression relative to the lowest expected loop temperature. C) The brand name of the glycol. D) The solution’s taste. Answer: B Explanation: The antifreeze must prevent freezing at the lowest loop temperature while maintaining acceptable viscosity for pump performance. Question 18. The head loss in a ground loop is primarily a function of: A) The length of the loop and flow velocity. B) The depth of the borehole only. C) The type of refrigerant used in the heat pump. D) The number of occupants in the building.
Answer: A Explanation: Pressure drop (head loss) increases with longer pipe runs and higher fluid velocities. Question 19. A water‑to‑water geothermal heat pump with a COP of 4.5 indicates: A) The system delivers 4.5 kW of heating for every 1 kW of electrical input. B) The system uses 4.5 kW of electricity to produce 1 kW of heat. C) The system can only operate in cooling mode. D) The system’s efficiency is below that of a standard electric resistance heater. Answer: A Explanation: COP (Coefficient of Performance) is the ratio of heating output to electrical input; a COP of 4.5 means 4.5 kW heat per 1 kW electricity. Question 20. When integrating a desuperheater for domestic hot water (DHW) with a geothermal heat pump, the desuperheater extracts heat from: A) The refrigerant’s superheated vapor after the compressor. B) The outdoor ambient air. C) The ground loop fluid before it enters the heat pump. D) The building’s return water loop. Answer: A Explanation: A desuperheater captures waste heat from the refrigerant’s superheated vapor, improving DHW efficiency.
Answer: B Explanation: Entrapped air lowers flow, creates noise, and can damage pumps; purging removes it. Question 24. Which of the following is a common failure mode in a geothermal loop that can be diagnosed by an unexpected high pressure drop? A) Refrigerant leak in the heat pump. B) Blockage or debris accumulation in the ground loop. C) Incorrect thermostat programming. D) Oversized heat pump capacity. Answer: B Explanation: A blockage or debris reduces pipe cross‑section, causing increased pressure drop. Question 25. A life‑cycle cost (LCC) analysis compares geothermal to conventional HVAC primarily by evaluating: A) Initial equipment cost only. B) Energy consumption, maintenance, and replacement costs over the system’s service life. C) The number of patents held by the manufacturer. D) The color of the heat pump unit. Answer: B Explanation: LCC accounts for all costs over the system’s lifespan, not just upfront expense. Question 26. Which federal incentive, as of the latest code, provides a tax credit for residential geothermal heat pump installations?
A) Section 179 deduction B) Investment Tax Credit (ITC) C) Energy Star rebate D. None; geothermal systems are not eligible for federal tax credits. Answer: B Explanation: The Residential Energy Efficient Property Credit (ITC) offers a percentage credit for qualifying geothermal installations. Question 27. The IGSHPA C‑448 standard primarily addresses: A. Electrical wiring methods for heat pumps. B. Design and installation of ground‑source heat pump systems. C. Fire safety in HVAC rooms. D. Noise control for outdoor condensers. Answer: B Explanation: C‑448 is the industry standard for designing and installing GSHP systems. Question 28. When drilling a vertical borehole, the purpose of installing a casing is to: A. Increase the borehole’s thermal conductivity. B. Prevent collapse of the borehole and protect groundwater from contamination. C. Reduce the length of the borehole needed. D. Serve as the primary heat‑transfer element. Answer: B Explanation: Casing stabilizes the borehole and isolates the ground loop from the surrounding formation.
D. Variation in refrigerant charge. Answer: B Explanation: Thermal drift is the cumulative effect of excess heat injection or extraction on the surrounding ground temperature. Question 32. Which measurement is most directly used to determine the effective thermal conductivity of the soil during a TRT? A. Temperature rise of the circulating fluid over time. B. Ambient air temperature fluctuations. C. Electrical resistivity of the soil. D. Soil moisture content measured with a hygrometer. Answer: A Explanation: The rate at which the fluid temperature rises (or falls) under constant power input reveals the soil’s effective thermal conductivity. Question 33. A common environmental concern associated with grout used in borehole installation is: A. Excessive heat generation during curing. B. Potential leaching of chemicals into groundwater if not properly sealed. C. High acoustic emissions during injection. D. Grout causing magnetic interference with nearby electronics. Answer: B Explanation: Certain grout materials can release chemicals; proper selection and placement mitigate groundwater contamination.
Question 34. When sizing a heat pump for a commercial building, the term “design temperature” typically refers to: A. The average outdoor temperature over a year. B. The outdoor temperature at which the system must meet peak heating or cooling loads. C. The temperature of the refrigerant at the compressor inlet. D. The temperature of the building’s interior air. Answer: B Explanation: Design temperatures are extreme outdoor conditions used to size equipment for peak loads. Question 35. In a water‑to‑air geothermal heat pump, the term “EER” (Energy Efficiency Ratio) is defined as: A. Heating output divided by electrical input. B. Cooling output (BTU/h) divided by electrical input (W). C. The ratio of refrigerant pressure to ambient pressure. D. The number of hours the system can run on battery backup. Answer: B Explanation: EER measures cooling efficiency; it is the cooling capacity in BTU/h per watt of electricity. Question 36. Which of the following pump selection criteria is most critical for ensuring adequate flow in a long horizontal loop field? A. Pump’s motor brand. B. Pump’s head rating relative to calculated pressure drop.
Question 39. The primary reason for installing a backflow preventer on an open‑loop geothermal well is to: A. Increase the system’s COP. B. Prevent contaminated water from entering the municipal water supply. C. Reduce the acoustic noise of the pump. D. Allow the pump to run at higher speeds. Answer: B Explanation: Backflow preventers protect public water sources from potential contamination when the system discharges water. Question 40. In a geothermal loop, the term “hydraulic balancing” refers to: A. Matching the heat pump’s refrigerant charge to the loop size. B. Adjusting flow rates so each loop segment receives the designed fluid velocity. C. Equalizing the temperature of the fluid entering and leaving the heat pump. D. Synchronizing the pump’s speed with the building’s thermostat. Answer: B Explanation: Hydraulic balancing ensures uniform flow distribution across all loop sections for optimal heat transfer. Question 41. Which of the following pipe materials is most commonly used for closed‑loop geothermal systems due to its flexibility and resistance to corrosion? A. Copper B. PVC C. HDPE (high‑density polyethylene) D. Galvanized steel
Answer: C Explanation: HDPE is flexible, chemically inert, and suitable for long buried runs in geothermal loops. Question 42. The “thermal conductivity” of a material is expressed in units of: A. W/(m·K) B. J/(kg·K) C. Pa·s D. kWh/m³ Answer: A Explanation: Thermal conductivity quantifies heat flow per unit length per temperature gradient, expressed in watts per meter‑kelvin. Question 43. When performing a pumping test on an open‑loop well, the key parameter to determine is: A. The well’s static water level. B. The well’s hydraulic conductivity (K) and sustainable yield. C. The color of the groundwater. D. The borehole diameter only. Answer: B Explanation: Pumping tests assess how much water can be sustainably extracted and the aquifer’s hydraulic properties. Question 44. A geothermal designer must consider “load diversity” because:
Answer: B Explanation: TEN is the pipe infrastructure that transports thermal energy among participants in a district system. Question 47. Which calculation is essential for determining the required pipe diameter in a geothermal loop to keep the fluid velocity within acceptable limits? A. Reynolds number for turbulent flow. B. Darcy‑Weisbach equation for pressure drop. C. Bernoulli’s principle for static pressure. D. Fourier’s law for heat conduction. Answer: B Explanation: The Darcy‑Weisbach equation relates flow rate, pipe size, fluid properties, and pressure loss, guiding pipe sizing. Question 48. A key advantage of using a pond or lake loop over a vertical borehole is: A. Higher thermal conductivity of water compared to soil. B. No need for any pumping equipment. C. Elimination of refrigerant use. D. Ability to operate without any heat pump. Answer: A Explanation: Water has higher thermal conductivity, allowing efficient heat exchange with a relatively short loop in a pond or lake.
Question 49. Which of the following is a primary reason for performing a “soil borings and sampling” before installing a geothermal system? A. To determine the color of the soil for aesthetic purposes. B. To assess soil stratigraphy, moisture, and thermal properties for accurate GHX design. C. To measure the soil’s magnetic field strength. D. To locate underground wildlife habitats. Answer: B Explanation: Soil borings provide data on layers, moisture, and thermal conductivity essential for loop sizing. Question 50. In the context of geothermal system commissioning, “baseline performance testing” typically includes measuring: A. The building’s occupancy schedule. B. Flow rate, inlet/outlet temperatures, and electrical power consumption at defined load conditions. C. The color of the heat pump’s exterior paint. D. The number of LEDs in the control panel. Answer: B Explanation: Baseline testing records key operational parameters to verify that the system meets design expectations. Question 51. Which of the following is NOT a typical method for mitigating thermal interference between adjacent boreholes? A. Increasing borehole spacing. B. Using higher‑conductivity grout. C. Installing boreholes at shallower depths.
