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. What is a common tool used in Ground Loop & Heat Pump Configuration? → Manual J and Manual S
5. What is the standard control voltage used in residential geothermal heat pump low-voltage wiring between the thermostat and air handler? → 24V AC
6. Why is soil thermal conductivity important in geothermal design? → It impacts the system's heating and cooling efficiency
7. What is the PRIMARY purpose of obtaining CRD certification in Certified Residential Geothermal Designer? → To demonstrate verified competency and adherence to professional standards
8. What distinguishes a Certified Residential Geothermal Designer certified professional from a non-certified practitioner? → Certification validates competency through standardized assessment against benchmarks
9. How frequently should ongoing assessments be conducted in Certified Residential Geothermal Designer practice? → At regular intervals and as conditions change
10. 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
11. 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
12. What is the role of the heat pump in Ground Loop & Heat Pump Configuration? → To transfer heat efficiently
13. What is the function of the expansion valve in a geothermal heat pump? → Regulates refrigerant flow and pressure
14. What is the MOST effective way for new CRD professionals to build competency? → Combining formal education, mentored practice, and ongoing professional development
15. 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
16. How do environmental compliance regulations impact Installation Standards & Environmental Compliance? → They ensure sustainable practices
17. Why is maintenance important in Installation Standards & Environmental Compliance? → To keep systems running efficiently
18. What is a common tool used in Installation Standards & Environmental Compliance? → Manual J and Manual S
19. Which foundational principle is MOST important for success in Certified Residential Geothermal Designer? → Commitment to continuous learning, ethical practice, and quality outcomes
20. What is the MOST important factor when selecting assessment tools for CRD certification work? → Validity, reliability, and appropriateness for the specific context
21. How do environmental compliance regulations impact Ground Loop & Heat Pump Configuration? → They ensure sustainable practices
22. What is the main goal of Ground Loop & Heat Pump Configuration? → To optimize system performance and efficiency
23. What is the main goal of Residential Energy Efficiency & Load Calculations? → To optimize system performance and efficiency
24. Which factor is critical when sizing a geothermal system? → Load calculation
25. What is the MOST effective way for new CRD professionals to build competency? → Combining formal education, mentored practice, and ongoing professional development
26. What is a common tool used in Residential Energy Efficiency & Load Calculations? → Manual J and Manual S
27. In CRD practice, what happens when regulations are updated? → Professionals must update knowledge and practices to meet new requirements
28. When two or more geothermal heat pumps serve a single residence, which control strategy best equalizes wear and extends equipment life? → Lead-lag sequencing with automatic runtime hour balancing between units
29. Which foundational principle is MOST important for success in Certified Residential Geothermal Designer? → Commitment to continuous learning, ethical practice, and quality outcomes
30. What is the MOST important factor when selecting assessment tools for CRD certification work? → Validity, reliability, and appropriateness for the specific context