- Identity and Status: What This Cheat Sheet Covers
- The Nine Preparation Headings at a Glance
- Concepts You Must Be Able to Explain Cold
- Load Calculations and Heat Pump and Pipe Design
- Economics of Design: The Last Heading
- Renewal Facts for Active Holders
- One-Table Summary
- Mapping the Headings to a Review Calendar
- Frequently Asked Questions
- CRD here means Certified Residential Geothermal Designer, issued by the International Ground Source Heat Pump Association (IGSHPA).
- IGSHPA treats CRD as a legacy credential; new-candidate availability is on verification hold, not open enrollment.
- Nine historical preparation headings run from GSHP benefits through load calculations to the economics of design.
- Active holders renew at $75 per year (members) or $225 per year (non-members), with CEU documentation.
Identity and Status: What This Cheat Sheet Covers
This page is a one-sheet review of the Certified Residential Geothermal Designer credential from IGSHPA. It is a designer-level credential for ground source heat pump (GSHP) work in homes, and it is a different thing from any other certification that happens to share the three letters. If you landed here looking for something else, check the What Does CRD Stand For? explainer before going further.
The most important fact on the sheet is not technical. IGSHPA's January 2026 white paper on sunsetting legacy training courses and certifications names CRD as a legacy credential. The paper reports that normal legacy training was replaced by the end of 2025. Active holders may keep renewing indefinitely, provided they meet continuing education requirements and never let the certification lapse. Taking the GRSD examination is a separate, optional upgrade path. It does not automatically rename or replace CRD.
The Nine Preparation Headings at a Glance
The curriculum scope comes from IGSHPA's historical event listing for the CRD course delivered online with HRAI in February 2025. That listing presented nine topic headings without weights. Two cautions apply. These are preparation headings, not an official weighted exam blueprint, and no heading can be called the highest-weighted. And the listing ties certification to passing the corresponding examination, but this research did not verify a current legacy-exam question count, time limit, passing mark or initial exam fee. Anyone quoting those numbers for CRD is guessing or borrowing from another credential. The full breakdown lives in CRD Exam Domains 2026: Complete Guide to All 9 Content Areas.
- Ground Source Heat Pump Benefits
- System Components
- Heat Pump Types
- Design Process
- Energy Requirements
- Load Calculations
- Parameters that affect different types of heat pump performance, site, geology and soil conditions
- Heat pump and pipe design
- Economics of design
Notice the arc. The sequence moves from "why GSHP" to "what is in the system" to "how do you size and lay it out" to "does it pay back." A residential designer needs all four layers, and the credential's scope reflects that.
Concepts You Must Be Able to Explain Cold
Benefits, Components and Heat Pump Types
Ground Source Heat Pump Benefits
Be ready to explain, in plain language, why a homeowner would choose a ground loop over conventional equipment and where the advantage comes from.
- The ground as a thermal source and sink with relatively stable temperatures compared with outdoor air
- Efficiency gains from exchanging heat with the earth rather than fighting extreme air temperatures
- Heating, cooling and potential domestic hot water services from one system
- Honest limits: higher first cost and site dependence
System Components
A designer must treat the system as three connected parts rather than one box.
- The ground heat exchanger (the buried loop)
- The heat pump unit itself
- The distribution system that delivers heating and cooling inside the home
- Circulation, flow and the interfaces between these parts
Heat Pump Types
Know the major configurations and when each fits a residential job.
- Water-to-air versus water-to-water equipment and what each serves
- Closed-loop versus open-loop thinking at a conceptual level
- How equipment type connects to the distribution system you are designing for
Design Process and Energy Requirements
The Design Process heading is about sequence and discipline: gather site and building information, establish loads, select equipment, size the ground exchanger, and check the result against economics. Candidates tend to stumble when they memorize steps without understanding dependencies. A load error upstream propagates into equipment selection and loop length downstream. The Energy Requirements heading ties building demand to what the system must deliver over a season, not just at a peak moment. Practice articulating the difference between an instantaneous peak and a seasonal energy picture, because the two drive different decisions.
Load Calculations and Heat Pump and Pipe Design
Load Calculations
Load calculation is the foundation heading. Everything that follows, from equipment capacity to loop length, rests on a defensible building load. Expect to be comfortable with the logic of heating and cooling loads for a residence: envelope losses and gains, infiltration and ventilation, internal gains, and how design conditions are chosen. The practical lesson is that oversizing is not a safe default. It raises installed cost, can hurt comfort and part-load behavior, and in a ground-coupled system it inflates the buried loop you have to pay for.
Site, Geology and Soil Conditions
The seventh heading is the one that separates GSHP design from ordinary mechanical design. Ground thermal behavior depends on the site. Soil and rock type, moisture, groundwater presence and available land all shape how much heat a loop can exchange. A designer who treats the ground as a uniform constant will mis-size loops. Be able to explain, qualitatively, why two lots in the same neighborhood might need different loop designs, and which site facts you would want before committing to a layout.
Heat Pump and Pipe Design
Heat pump and pipe design
This is where load, equipment and site converge into a buildable design.
- Matching equipment capacity to the calculated load, heating and cooling both
- Sizing the ground exchanger to balance what the building demands against what the ground can supply
- Hydraulic thinking: flow, pressure drop and circulation in the loop piping
- Loop configuration choices and how site constraints push you toward one layout or another
Key Takeaway
Treat load, site and loop design as one chain. When practicing, always ask which upstream assumption a given answer depends on. If you cannot name it, you do not yet own the concept.
Economics of Design: The Last Heading
The ninth heading closes the loop between engineering and the customer's decision. A residential designer is also a salesperson of sorts, and the homeowner will ask whether the system pays for itself. Be prepared to discuss first cost versus operating cost, how loop and drilling or excavation costs weigh on the budget, and how to compare a GSHP against conventional alternatives on a lifecycle basis. Do not memorize payback figures from marketing material. Learn the method, because the numbers change with energy prices, incentives and local installation costs. If you are weighing the career side of this, Is the CRD Certification Worth It? Complete ROI Analysis 2026 applies the same lifecycle thinking to the credential itself.
Renewal Facts for Active Holders
For existing holders, renewal is where the money and the risk live. IGSHPA's renewal policy (fee policy effective January 1, 2024) offers one-, two- or three-year renewal terms. The listed rates are $75 per year for members and $225 per year for non-members. These are renewal charges, not initial exam fees, and nobody should quote them as the cost to become certified.
- CEU documentation: required for processing a renewal.
- CEU scale: IGSHPA describes eight CEU points per three-year cycle. These are points, not eight classroom hours.
- Membership coverage: the membership term must cover the discounted certification-renewal term.
- Individual membership: $125 per year for currently employed professionals. Separate individual membership is unnecessary if you are covered by an eligible business, community or utility membership.
- Lapse risk: IGSHPA's FAQ says lapsed legacy credentials cannot be reinstated.
One-Table Summary
| Item | What the Verified Facts Say |
|---|---|
| Credential | Certified Residential Geothermal Designer (CRD) |
| Issuer | International Ground Source Heat Pump Association (IGSHPA) |
| Status | Legacy credential; active holders may renew indefinitely if they do not lapse |
| New candidates | Verification hold; legacy courses considered case by case for utility, state or provincial programs |
| Upgrade path | GRSD examination, optional and separate; not an automatic rename |
| Curriculum scope | Nine historical, unweighted preparation headings |
| Renewal terms | One, two or three years |
| Renewal rate | $75 per year (member); $225 per year (non-member) |
| CEUs | Eight CEU points per three-year cycle; documentation required |
| Individual membership | $125 per year, currently employed professionals |
| Lapsed credential | Cannot be reinstated |
| Exam format details | Current legacy question count, time limit, passing mark and initial fee not verified |
That last row is deliberate. Several sites publish confident exam specifics for this credential. None could be tied to an IGSHPA source during research, so this cheat sheet leaves them blank rather than guess. See CRD Passing Score 2026 and CRD Pass Rate 2026: What the Data Shows for how to think about missing numbers responsibly.
Mapping the Headings to a Review Calendar
If you are refreshing knowledge for a legacy program requirement or a transition conversation, a sequenced pass through the headings works better than random review. Order matters because later headings depend on earlier ones.
Foundations: Benefits, Components, Types
- Explain GSHP benefits and honest limits out loud
- Sketch the three-part system and label each interface
- Compare heat pump types by what they serve
Process and Energy, then Loads
- Write the design sequence with inputs and outputs per step
- Contrast peak demand with seasonal energy
- Work load calculation logic until envelope, infiltration and gains feel routine
Site Conditions, Heat Pump and Pipe Design
- List the site facts you would gather before sizing a loop
- Walk one residence from load to equipment to loop concept
- Review hydraulic basics for loop piping
Economics and Integration
- Practice a lifecycle cost comparison against a conventional system
- Revisit weak headings, then take mixed practice questions on the main practice test site
Sequencing by dependency is the only study method worth mentioning here, because the headings genuinely build on each other. For a broader look at the material and its difficulty, read How Hard Is the CRD Exam? Complete Difficulty Guide 2026.
Frequently Asked Questions
Not on the strength of anything verified. IGSHPA offers legacy courses case by case, and only when a utility, state or provincial program requires them. New-candidate availability remains on verification hold until a specific current offering is confirmed with the issuer. A past HRAI schedule listing is not proof of open enrollment.
No. IGSHPA describes the GRSD examination as a separate, optional upgrade path. It is not an automatic renaming or replacement of the CRD, so existing holders can keep renewing the CRD on its own terms.
Current renewal products are priced at $75 per year for members and $225 per year for non-members, available in one-, two- or three-year terms. CEU documentation is required for processing. These are renewal charges, not initial exam fees. Details are in the CRD certification cost breakdown.
IGSHPA's FAQ states that lapsed legacy credentials cannot be reinstated. That makes timely renewal the single most protective action an active holder can take.
No verified source supports an answer. The nine headings come from a historical, unweighted listing and are not a current weighted blueprint. Prepare all of them, with extra attention to load calculations and site conditions because the later design headings depend on them.