IGSHPA Certified Residential Geothermal Designer (CRD) — Questions and Answers

Question 1: What is the purpose of a pressure test performed on a closed-loop geothermal ground loop before system startup?

To measure the static ground pressure at loop depth
To verify loop integrity by detecting leaks before backfilling or system connection (Correct answer)
To calibrate the heat pump refrigerant circuit
To determine soil permeability for loop sizing

Correct answer: To verify loop integrity by detecting leaks before backfilling or system connection

Pressure testing the loop prior to backfill and connection confirms there are no leaks in the piping that would cause fluid loss and system failure.

Question 2: Which monitoring system capability allows a geothermal contractor to diagnose operational faults and review performance data without an on-site visit?

Manual weekly inspection logs completed by the homeowner
Standard analog thermostat with a paper log attached for homeowner use
Web-connected smart thermostat or building automation system with geothermal-compatible remote access (Correct answer)
Pneumatic control system with local gauge readouts

Correct answer: Web-connected smart thermostat or building automation system with geothermal-compatible remote access

Web-connected smart thermostats and cloud-enabled building automation systems transmit real-time performance data and fault codes, enabling remote diagnostics and proactive maintenance.

Question 3: What is the PRIMARY reason for regulatory compliance in the Certified Residential Geothermal Designer profession?

To justify higher service fees
To create additional paperwork
To avoid penalties and fines only
To protect public safety, ensure quality, and maintain professional integrity (Correct answer)

Correct answer: To protect public safety, ensure quality, and maintain professional integrity

Regulatory compliance protects public safety, ensures quality, and maintains professional integrity.

Question 4: When two or more geothermal heat pumps serve a single residence, which control strategy best equalizes wear and extends equipment life?

Always run the same unit as the lead and use the second only as emergency backup
Alternate units on a fixed 24-hour time-of-day schedule
Run all units simultaneously at all times regardless of load
Lead-lag sequencing with automatic runtime hour balancing between units (Correct answer)

Correct answer: Lead-lag sequencing with automatic runtime hour balancing between units

Lead-lag control with runtime equalization automatically rotates which unit leads, ensuring both accumulate similar operating hours and neither experiences disproportionate wear.

Question 5: A designer is evaluating a pond loop for a residential system. What minimum pond volume (in acre-feet) per ton of system capacity is generally recommended?

10 acre-ft per ton
5 acre-ft per ton
1.5 acre-ft per ton (Correct answer)
0.25 acre-ft per ton

Correct answer: 1.5 acre-ft per ton

Approximately 1.5 acre-feet of pond volume per ton of heating/cooling capacity is the commonly cited minimum to provide adequate thermal mass and recovery.

Question 6: What is the BEST way for a Certified Residential Geothermal Designer professional to stay current with regulatory changes?

Check regulations only during renewal
Monitor regulatory bodies, attend CE, and participate in professional associations (Correct answer)
Depend on colleagues to share updates
Rely solely on employer notifications

Correct answer: Monitor regulatory bodies, attend CE, and participate in professional associations

Staying current requires monitoring agencies, attending CE, and participating in professional associations.

Question 7: Why is maintenance important in Installation Standards & Environmental Compliance?

To keep systems running efficiently (Correct answer)
To shorten system lifespan.
To increase energy bills.
To ignore leaks.

Correct answer: To keep systems running efficiently

Regular maintenance is vital for ensuring the continuous efficient operation of geothermal systems, which is a key aspect of both installation standards and environmental compliance. It helps prevent performance degradation, extends the system's lifespan, and ensures it continues to meet its designed energy efficiency targets. This minimizes its environmental footprint and operational costs.

Question 8: A residential geothermal designer is comparing two loop configurations with different installed costs. Which analysis method should be used to determine which provides better long-term value?

Flipping a coin since both configurations provide the same energy output
Choosing the configuration with the highest installed cost to ensure quality
Lifecycle cost analysis comparing total costs including installation, operation, and maintenance over the project life (Correct answer)
Selecting the configuration with the lowest installed cost regardless of operating costs

Correct answer: Lifecycle cost analysis comparing total costs including installation, operation, and maintenance over the project life

Lifecycle cost analysis is the proper tool for comparing alternatives because a higher upfront cost can yield lower total cost through reduced energy consumption.

Question 9: Which factor is critical in Ground Loop & Heat Pump Configuration?

Random equipment selection.
Skipping insulation.
Accurate load calculation (Correct answer)
Ignoring building size.

Correct answer: Accurate load calculation

Accurate load calculation is critical because it precisely determines a building's heating and cooling requirements. This ensures the geothermal heat pump and ground loop are correctly sized, preventing inefficiencies from oversizing or undersizing, and guaranteeing optimal system performance and comfort.

Question 10: Which window property most directly affects the cooling load from solar radiation?

Center-of-glass R-value
U-factor
Visible Light Transmittance (VLT)
Solar Heat Gain Coefficient (SHGC) (Correct answer)

Correct answer: Solar Heat Gain Coefficient (SHGC)

SHGC measures the fraction of incident solar radiation admitted through a window, making it the primary factor for solar-driven cooling loads.

Question 11: When assessment results for a Certified Residential Geothermal Designer evaluation are inconclusive, the BEST practice is to:

Delay reporting until results are favorable
Discard the results and start over
Conduct additional assessment using alternative methods (Correct answer)
Report the results as definitive anyway

Correct answer: Conduct additional assessment using alternative methods

Inconclusive results require additional assessment using alternative methods for triangulation.

Question 12: Which regulatory requirement is UNIVERSAL across all Certified Residential Geothermal Designer practice settings?

Using specific proprietary software
Maintaining current certification and continuing education (Correct answer)
Limiting services to local jurisdictions
Working exclusively during business hours

Correct answer: Maintaining current certification and continuing education

Maintaining current certification and continuing education is a universal regulatory requirement.

Question 13: In a residential geothermal installation, why is it important to verify that the circuit breaker size matches the unit's Maximum Overcurrent Protection (MOP) rating on the nameplate?

Correct breaker sizing ensures adequate short circuit and overload protection without nuisance tripping (Correct answer)
The MOP rating determines the minimum wire gauge only
Oversized breakers save energy by reducing voltage drops
Breaker size affects the COP rating of the heat pump

Correct answer: Correct breaker sizing ensures adequate short circuit and overload protection without nuisance tripping

Installing a breaker at or below the nameplate MOP rating ensures proper overcurrent protection that safely interrupts faults while allowing normal starting current without nuisance trips.

Question 14: What type of wiring installation is required for geothermal ground loop electrical connections that transition from underground to inside the building?

THHN conductors run in open air above the ground surface only
Standard residential NM-B cable run along the foundation
Direct burial-rated cable or appropriate conductors in listed conduit (Correct answer)
Low-voltage thermostat wire rated for 24V

Correct answer: Direct burial-rated cable or appropriate conductors in listed conduit

Underground electrical connections to flow center pumps must use UF-B (underground feeder) direct burial cable or THWN/THWN-2 conductors in listed conduit rated for wet locations.

Question 15: What voltage supply is most commonly used for residential geothermal heat pump compressors in the United States?

277V single-phase
480V three-phase
208/230V single-phase (Correct answer)
120V single-phase

Correct answer: 208/230V single-phase

Residential geothermal heat pumps in the US are designed for 208/230V single-phase power, which is the standard service voltage available in most homes.

Question 16: When documenting assessment findings in CRD practice, which approach is MOST appropriate?

Include only positive findings
Record objective findings, measurements, and observations factually (Correct answer)
Use jargon only experts understand
Summarize verbally without written documentation

Correct answer: Record objective findings, measurements, and observations factually

Assessment documentation must be objective, factual, and comprehensive.

Question 17: What is 'thermal short-circuiting' in a vertical borehole and how is it mitigated?

Heat transfer between the supply and return pipes within the same bore; mitigated by using thermally enhanced grout and proper pipe spacing (Correct answer)
Fluid bypassing the heat pump; fixed by adding a check valve
Ground water infiltration into the borehole; fixed by casing
Electrical short in the pump motor; fixed by grounding

Correct answer: Heat transfer between the supply and return pipes within the same bore; mitigated by using thermally enhanced grout and proper pipe spacing

Thermal short-circuiting occurs when heat from the warmer pipe leg transfers directly to the cooler leg inside the bore, reducing efficiency; proper grout and U-tube spacing reduce it.

Question 18: Which documentation practice BEST demonstrates regulatory compliance for CRD certified professionals?

Filing documents only when audited
Relying on memory for routine procedures
Maintaining organized, dated, and signed records of all activities (Correct answer)
Keeping informal handwritten notes

Correct answer: Maintaining organized, dated, and signed records of all activities

Organized, dated, and signed records demonstrate systematic regulatory compliance.

Question 19: Which financial instrument specifically designed for energy efficiency upgrades allows homeowners to finance geothermal installations through their property tax assessment?

Property Assessed Clean Energy (PACE) financing (Correct answer)
A USDA farm operating loan
A standard home equity line of credit (HELOC)
A manufacturer's deferred payment plan

Correct answer: Property Assessed Clean Energy (PACE) financing

PACE financing attaches repayment to the property tax bill rather than the individual, making it accessible to homeowners who lack equity for a HELOC.

Question 20: Which type of thermostat is most recommended for geothermal heat pump systems to prevent unnecessary auxiliary heat activation?

Single-stage manual thermostat
Two-stage thermostat with intelligent recovery (Correct answer)
Standard programmable thermostat without staging
Outdoor temperature-only reset thermostat

Correct answer: Two-stage thermostat with intelligent recovery

Two-stage thermostats with intelligent recovery gradually bring the space to setpoint using only the heat pump, avoiding premature activation of auxiliary resistance heat.

Question 21: In a geothermal heat pump system, what does an auxiliary heat 'lockout' control primarily accomplish?

Prevents the system from operating during utility demand response events
Locks out the ground loop pump when loop temperatures are too high
Prevents the heat pump from running when outdoor temperatures exceed 65°F
Prevents backup resistance heat from activating when the heat pump can adequately handle the load (Correct answer)

Correct answer: Prevents backup resistance heat from activating when the heat pump can adequately handle the load

An auxiliary heat lockout control inhibits backup resistance elements from energizing whenever the heat pump is capable of maintaining comfort, preserving system efficiency.

Question 22: In a variable-speed geothermal heat pump, what sensor signal most commonly modulates compressor speed?

Loop entering water temperature (Correct answer)
Outdoor air temperature
Supply air static pressure
Refrigerant discharge superheat

Correct answer: Loop entering water temperature

The entering water temperature (EWT) from the ground loop is the primary control signal that tells the variable-speed compressor how hard to work.

Question 23: What is the purpose of a pre-construction site assessment in residential geothermal project management?

To identify site constraints such as setbacks, utility conflicts, soil conditions, and access for drilling equipment (Correct answer)
To size the electrical panel for the home's appliances
To determine the homeowner's credit score for financing
To select interior paint colors for the mechanical room

Correct answer: To identify site constraints such as setbacks, utility conflicts, soil conditions, and access for drilling equipment

A pre-construction site assessment identifies physical constraints that affect loop placement, equipment access, and overall project feasibility before signing contracts.

Question 24: How frequently should ongoing assessments be conducted in Certified Residential Geothermal Designer practice?

Once annually regardless of circumstances
Only when required by external auditors
At regular intervals and as conditions change (Correct answer)
Only when problems are reported

Correct answer: At regular intervals and as conditions change

Ongoing assessments should follow established protocols and also respond to changing conditions.

Question 25: For geothermal system sizing, the peak cooling load is most influenced by:

Solar heat gain through windows and roof (Correct answer)
Duct leakage into unconditioned spaces
Thermostat setpoint differential
Ground loop entering water temperature in winter

Correct answer: Solar heat gain through windows and roof

Solar heat gain through glazing and roofing materials is typically the dominant driver of residential peak cooling loads in summer.

Question 26: A geothermal heat pump system has a COP of 4.0 in heating mode. If it delivers 48,000 BTU/hr of heat, how much electrical power does it consume?

4,000 W
12,000 W
3,500 W
3,517 W (Correct answer)

Correct answer: 3,517 W

Power = Output/COP = 48,000 BTU/hr ÷ 4.0 = 12,000 BTU/hr input; converting: 12,000 / 3.412 ≈ 3,517 W.

Question 27: Which factor is critical in Installation Standards & Environmental Compliance?

Accurate load calculation (Correct answer)
Random equipment selection.
Skipping insulation.
Ignoring building size.

Correct answer: Accurate load calculation

Accurate load calculation is fundamental to both proper installation and environmental compliance because it dictates the correct sizing of the geothermal system. An accurately sized system operates efficiently, reducing energy consumption and environmental impact. Conversely, an improperly sized system can lead to inefficiencies, increased energy use, and potential compliance issues.

Question 28: What is a common tool used in Residential Energy Efficiency & Load Calculations?

Manual L.
Manual X.
Manual Z.
Manual J and Manual S (Correct answer)

Correct answer: Manual J and Manual S

Manual J and Manual S are common tools used in Residential Energy Efficiency & Load Calculations. ACCA Manual J is the industry standard for calculating a building's heating and cooling loads, while Manual S is used for properly selecting and sizing HVAC equipment based on those load calculations. Together, they ensure optimal system design and performance.

Question 29: Which loop configuration is most appropriate for a residential site with limited land area but access to deep drilling?

Horizontal slinky loops
Pond/lake loops
Vertical closed-loop boreholes (Correct answer)
Surface water open-loop

Correct answer: Vertical closed-loop boreholes

Vertical closed-loop boreholes require a small surface footprint because heat exchange length is achieved by drilling deep rather than spreading horizontally.

Question 30: What documentation is typically required by a lender when a homeowner finances a geothermal system through a green energy loan program?

Manufacturer's sales brochures without contractor quotes
Only a verbal agreement with the installer
Proof of homeowner's existing HVAC brand preference
A signed contractor proposal, permit documentation, and evidence of system qualification such as ENERGY STAR certification (Correct answer)

Correct answer: A signed contractor proposal, permit documentation, and evidence of system qualification such as ENERGY STAR certification

Green energy lenders require contractor proposals, permits, and certification evidence to confirm the system qualifies for the program's favorable terms.

Question 31: In the IGSHPA design method, what does the 'run fraction' (PLF) account for?

Fraction of time the heat pump operates at full load during the design month (Correct answer)
Proportion of glycol to water in the heat transfer fluid
Percentage of loop buried below frost line
Ratio of horizontal to vertical loop length

Correct answer: Fraction of time the heat pump operates at full load during the design month

The part-load factor (PLF or run fraction) reflects that the heat pump cycles on and off, allowing the ground some thermal recovery between runs.

Question 32: How does the Net Present Value (NPV) method improve on simple payback when evaluating a geothermal investment?

NPV accounts for the time value of money by discounting future energy savings to their present-day worth (Correct answer)
NPV measures only the installation cost without considering savings
NPV and simple payback produce identical results in all scenarios
NPV ignores future savings and uses only first-year costs

Correct answer: NPV accounts for the time value of money by discounting future energy savings to their present-day worth

NPV discounts future cash flows at an assumed rate of return, providing a more accurate picture of true economic value than simple payback alone.

Question 33: What is the BEST way for a Certified Residential Geothermal Designer professional to stay current with regulatory changes?

Depend on colleagues to share updates
Check regulations only during renewal
Rely solely on employer notifications
Monitor regulatory bodies, attend CE, and participate in professional associations (Correct answer)

Correct answer: Monitor regulatory bodies, attend CE, and participate in professional associations

Staying current requires monitoring agencies, attending CE, and participating in professional associations.

Question 34: Which loop configuration is typically used when ground space is limited?

Open loop.
Vertical loop (Correct answer)
Pond loop.
Horizontal loop.

Correct answer: Vertical loop

A vertical loop configuration is typically used when ground space is limited because it involves drilling boreholes deep into the earth, allowing the pipes to extend vertically rather than horizontally across a large area. This design minimizes the surface footprint required for the ground heat exchanger while still providing effective heat transfer.

Question 35: What is the purpose of a flow center in a geothermal ground loop system?

To distribute conditioned air evenly through the duct system
To house the circulating pumps and provide a service/purging point for the ground loop (Correct answer)
To control refrigerant flow rate inside the heat pump
To monitor and log electrical power consumption of the system

Correct answer: To house the circulating pumps and provide a service/purging point for the ground loop

A flow center contains the ground loop circulating pumps, isolation valves, and purge ports, providing a single service location for the hydronic ground loop.

Question 36: When a CRD professional identifies a potential regulatory violation, the CORRECT first step is to:

Address it only if directly affected
Document the violation and report through proper channels (Correct answer)
Discuss it casually with coworkers
Wait to see if it resolves on its own

Correct answer: Document the violation and report through proper channels

Proper documentation and reporting through established channels ensures accountability.

Question 37: What is the primary function of a desuperheater in a residential geothermal heat pump system?

Remove excess heat from the compressor housing
Reduce electrical consumption during utility peak demand periods
Pre-heat domestic hot water using waste heat from the refrigerant cycle (Correct answer)
Regulate entering water temperature in the ground loop

Correct answer: Pre-heat domestic hot water using waste heat from the refrigerant cycle

A desuperheater captures high-temperature waste heat from the refrigerant before it reaches the condenser and uses it to pre-heat domestic hot water at no additional energy cost.

Question 38: In a hybrid geothermal system, a supplemental cooling tower is added primarily to:

Provide backup heating when the heat pump is in defrost mode
Pre-cool outdoor air before it enters the heat pump
Supply condenser water to a conventional chiller as a backup
Reject excess heat during cooling-dominated operation to reduce ground temperature rise (Correct answer)

Correct answer: Reject excess heat during cooling-dominated operation to reduce ground temperature rise

A cooling tower dissipates excess heat rejection in cooling-dominated climates, preventing long-term ground warming that would degrade heat pump COP over years.

Question 39: What is a common range for simple payback periods for residential geothermal heat pump installations in the US after applying federal tax credits?

30 to 50 years making them economically unattractive
Exactly 7 years for all installations
5 to 15 years depending on local energy prices, load, and installation cost (Correct answer)
Less than 1 year in all US climates

Correct answer: 5 to 15 years depending on local energy prices, load, and installation cost

After applying the 30% federal tax credit, most US residential geothermal installations see payback periods ranging from roughly 5 to 15 years depending on local conditions.

Question 40: What is the primary benefit of adding a buffer tank (or hydraulic separator) to a hydronic geothermal heat pump system?

It filters sediment and contaminants from the loop fluid
It adds thermal mass to prevent short cycling of the heat pump compressor (Correct answer)
It balances electrical load across the three phases of service
It stores excess ground loop antifreeze for seasonal use

Correct answer: It adds thermal mass to prevent short cycling of the heat pump compressor

A buffer tank provides thermal mass between the heat pump and the distribution system, ensuring the compressor runs for adequate minimum on-times and preventing short cycling.

Question 41: Which factor most significantly affects the simple payback period of a residential geothermal heat pump compared to a high-efficiency gas furnace and central AC system?

The brand of the thermostat used
The local cost of electricity versus natural gas and the heating/cooling load of the home (Correct answer)
The number of bedrooms in the home
The color of the heat pump cabinet

Correct answer: The local cost of electricity versus natural gas and the heating/cooling load of the home

Payback period is driven primarily by the energy cost differential between the geothermal system and the fossil fuel alternative it replaces.

Question 42: When a CRD professional identifies a potential regulatory violation, the CORRECT first step is to:

Address it only if directly affected
Wait to see if it resolves on its own
Discuss it casually with coworkers
Document the violation and report through proper channels (Correct answer)

Correct answer: Document the violation and report through proper channels

Proper documentation and reporting through established channels ensures accountability.

Question 43: Which of the following best describes 'degree-days' as used in energy consumption estimation?

Number of days per year when heating is required
Cumulative sum of daily mean temperature deviations from a base temperature (65°F) (Correct answer)
Monthly average outdoor temperature minus indoor setpoint
Total hours per year below freezing

Correct answer: Cumulative sum of daily mean temperature deviations from a base temperature (65°F)

Heating degree-days (HDD) sum the daily differences between 65°F and the average outdoor temperature, providing a seasonal measure of heating energy demand.

Question 44: What is the primary reason a designer would choose a slinky horizontal ground loop over a straight horizontal loop?

More heat exchange surface area per linear trench foot (Correct answer)
Better freeze protection in cold climates
Easier pressure testing after installation
Lower pumping energy due to reduced pipe length

Correct answer: More heat exchange surface area per linear trench foot

Slinky coils pack more pipe into each trench foot, increasing heat exchange area when land area is limited.

Question 45: What is the purpose of a pressure/temperature (P/T) port on a ground loop header?

To measure entering and leaving water conditions without draining the system (Correct answer)
To add antifreeze solution to the loop
To connect the loop to the domestic hot water desuperheater
To release excess loop pressure during thermal expansion

Correct answer: To measure entering and leaving water conditions without draining the system

P/T ports allow technicians to insert probes and read pressure and temperature data for diagnostics without breaking the sealed loop.

Question 46: When managing a residential geothermal project with multiple subcontractors (driller, plumber, electrician), what scheduling dependency is critical to sequence correctly?

All trades must work simultaneously on the first day only
The plumber must complete all work before drilling begins
The electrician must complete all wiring before any drilling begins
Drilling and loop installation must be complete before the plumber connects the loop to the heat pump, which must be set before the electrician wires it (Correct answer)

Correct answer: Drilling and loop installation must be complete before the plumber connects the loop to the heat pump, which must be set before the electrician wires it

The geothermal loop must be in the ground and connected before the heat pump can be powered and tested, establishing a strict sequential dependency.

Question 47: What is a common antifreeze used in closed-loop geothermal systems?

Ethylene glycol
Propylene glycol (Correct answer)
Mineral oil.
Water only.

Correct answer: Propylene glycol

Propylene glycol is a common antifreeze used in closed-loop geothermal systems because it lowers the freezing point of the circulating fluid, preventing damage to the pipes in cold conditions. It is preferred over ethylene glycol due to its lower toxicity, making it a safer and more environmentally friendly option for residential applications.

Question 48: A building has 2,400 sq ft of wall area with an overall U-factor of 0.065 BTU/hr·ft²·°F and a DTD of 65°F. What is the wall heat loss?

6,760 BTU/hr
15,600 BTU/hr
23,920 BTU/hr
10,140 BTU/hr (Correct answer)

Correct answer: 10,140 BTU/hr

Heat loss = U × Area × DTD = 0.065 × 2,400 × 65 = 10,140 BTU/hr.

Question 49: What is a common tool used in Installation Standards & Environmental Compliance?

Manual Z.
Manual X.
Manual L.
Manual J and Manual S (Correct answer)

Correct answer: Manual J and Manual S

Manual J and Manual S are industry-standard methodologies for calculating building heating/cooling loads and properly sizing HVAC equipment, respectively. Adhering to these manuals ensures that geothermal systems are designed to meet specific building requirements efficiently. This is a key aspect of both installation standards and environmental compliance for optimal performance and energy savings.

Question 50: What distinguishes a Certified Residential Geothermal Designer certified professional from a non-certified practitioner?

There is no meaningful difference
Certified professionals only work in larger organizations
Certification validates competency through standardized assessment against benchmarks (Correct answer)
Certified professionals always have more experience

Correct answer: Certification validates competency through standardized assessment against benchmarks

Certification provides objective validation of competency through standardized assessment.

IGSHPA Certified Residential Geothermal Designer (CRD)

The CRD certification, administered by IGSHPA, validates expertise in designing residential ground source heat pump systems, covering system design principles, load calculations, ground heat exchanger design, installation standards, controls, and economic analysis. The open-book exam requires a minimum 80% passing score.

Questions

120 min

Time Limit

80%

To Pass

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These practice questions were written with AI tools. They are not real exam questions. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy

Sources & references

Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy

igshpa.org — Renewal, fees, eligibility, score validity · verified Oct 2026
csagroup.org — Test delivery, exam format, passing score, renewal, retake policy, score release, time limit, score validity · verified Oct 2026