CRD Study Guide 2026
Everything you need to pass the CRD exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 CRD Exam Format at a Glance
📚 CRD Topics to Study (37)
✍️ Sample CRD Questions & Answers
1. Which HDPE pipe fusion method is most commonly specified for residential geothermal ground loop connections at header manifolds?
Socket fusion is the preferred method for joining smaller-diameter HDPE pipes (typically 3/4" to 2") used at geothermal header manifolds in residential installations.
2. In a closed-loop geothermal system, what is the primary purpose of the expansion tank?
The expansion tank accommodates the volumetric expansion and contraction of the loop fluid as its temperature changes, preventing dangerous pressure spikes.
3. Which window property most directly affects the cooling load from solar radiation?
SHGC measures the fraction of incident solar radiation admitted through a window, making it the primary factor for solar-driven cooling loads.
4. Which document is typically completed and left with the homeowner after geothermal system commissioning?
A commissioning report documenting all measured parameters provides the homeowner and future technicians with a performance baseline for the system.
5. In residential load calculations, infiltration is typically measured using which unit?
Infiltration in residential buildings is expressed as ACH (air changes per hour), representing how many times the home's air volume is replaced by outdoor air.
6. A Thermal Response Test (TRT) is performed on a pilot borehole. What is the primary output used by the designer?
A TRT measures the temperature rise of circulating fluid under a constant heat injection rate to back-calculate the ground's effective thermal conductivity and borehole resistance.