CRD Cheat Sheet 2026

The 30 highest-yield CRD facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. When preparing a geothermal project proposal for a homeowner, what energy cost escalation assumption is commonly used in long-term savings projections? → An annual energy cost escalation rate of 2–5% reflecting historical utility price trends
2. When assessment results for a Certified Residential Geothermal Designer evaluation are inconclusive, the BEST practice is to: → Conduct additional assessment using alternative methods
3. What environmental factors affect Residential Energy Efficiency & Load Calculations? → Soil type and temperature
4. A geothermal designer notes that a home has a high window-to-wall ratio on the south facade. How should this affect load calculation? → Increase both heating and cooling loads due to greater conductive and solar gain area
5. What is a common tool used in Ground Loop & Heat Pump Configuration? → Manual J and Manual S
6. What is the standard control voltage used in residential geothermal heat pump low-voltage wiring between the thermostat and air handler? → 24V AC
7. Why is soil thermal conductivity important in geothermal design? → It impacts the system's heating and cooling efficiency
8. In hot-humid climates, latent loads typically represent what approximate percentage of total cooling load? → 30–50%
9. What is the PRIMARY purpose of obtaining CRD certification in Certified Residential Geothermal Designer? → To demonstrate verified competency and adherence to professional standards
10. What distinguishes a Certified Residential Geothermal Designer certified professional from a non-certified practitioner? → Certification validates competency through standardized assessment against benchmarks
11. How frequently should ongoing assessments be conducted in Certified Residential Geothermal Designer practice? → At regular intervals and as conditions change
12. In Certified Residential Geothermal Designer, what is the PRIMARY purpose of conducting an initial assessment? → To establish a baseline and identify needs for appropriate action
13. The US federal residential clean energy tax credit currently allows homeowners to deduct what percentage of qualifying geothermal heat pump installation costs? → 30% of the total installed cost with no cap through 2032 under the Inflation Reduction Act
14. For geothermal system sizing, the peak cooling load is most influenced by: → Solar heat gain through windows and roof
15. What is the role of the heat pump in Ground Loop & Heat Pump Configuration? → To transfer heat efficiently
16. What is the function of the expansion valve in a geothermal heat pump? → Regulates refrigerant flow and pressure
17. What is the MOST effective way for new CRD professionals to build competency? → Combining formal education, mentored practice, and ongoing professional development
18. Which instrument is used to measure ground loop flow rate during commissioning of a closed-loop geothermal system? → Flow center with integrated flow meter or a clamp-on ultrasonic flow meter
19. How do environmental compliance regulations impact Installation Standards & Environmental Compliance? → They ensure sustainable practices
20. Which grout characteristic is most important for optimizing vertical bore thermal performance? → High thermal conductivity
21. Why is maintenance important in Installation Standards & Environmental Compliance? → To keep systems running efficiently
22. What is a common tool used in Installation Standards & Environmental Compliance? → Manual J and Manual S
23. Which foundational principle is MOST important for success in Certified Residential Geothermal Designer? → Commitment to continuous learning, ethical practice, and quality outcomes
24. What is the MOST important factor when selecting assessment tools for CRD certification work? → Validity, reliability, and appropriateness for the specific context
25. How do environmental compliance regulations impact Ground Loop & Heat Pump Configuration? → They ensure sustainable practices
26. What is the main goal of Ground Loop & Heat Pump Configuration? → To optimize system performance and efficiency
27. What is the main goal of Residential Energy Efficiency & Load Calculations? → To optimize system performance and efficiency
28. During a thermal response test (TRT), what two key ground parameters are determined? → Ground thermal conductivity and borehole thermal resistance
29. 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
30. Which factor is critical when sizing a geothermal system? → Load calculation