CGD (Certified GeoExchange Designer) renewal and exam help guide

CGD Status: Legacy Renewal-Only

AEE lists the Certified GeoExchange Designer program as a legacy certification and states that it is no longer accepting new applications. That changes how this service page should be used. New candidates should not treat CGD as an open application path. Current CGD certificants can focus on renewal, and current CGDIT holders can review whether they are eligible to upgrade to CGD under AEE's renewal-only status.

The original CGD program recognized professionals with experience, competence, proficiency, and ethical fitness in geothermal heat pump design and related disciplines. AEE's objectives included raising professional standards, improving commercial geothermal heat pump design practice, identifying professionals with acceptable knowledge through examination and standards of conduct, and awarding special recognition to qualified geothermal design professionals.

Renewal and Upgrade Path

For active CGD holders, the practical task is maintaining the credential rather than preparing as a first-time applicant. The CGD handbook describes a three-year certification maintenance cycle requiring professional credits and a recertification form. It also explains that a CGD holder who does not maintain credits can lose active status until reinstatement requirements are met.

For CGDIT holders, the handbook describes an in-training route where candidates who passed the exam but did not yet meet full experience requirements could later submit the completed CGD application and supporting documentation. AEE's current legacy page narrows that into renewal-only status for current CGDIT upgrades, so candidates should verify directly with AEE before assuming a new exam or application is available.

Historical Eligibility Requirements

The CGD handbook lists several historical prerequisite routes. These include a four-year mechanical engineering graduate, Registered Architect, or Certified Energy Manager with three years of verified commercial geothermal heat pump system project design experience; another four-year technical or non-technical degree with five years; a two-year technical degree with eight years; ten or more years of verified experience; or a valid Professional Engineer license with a minimum of three geothermal commercial projects.

The handbook also required a minimum of three completed commercial geothermal projects. Feasibility studies and incomplete projects were not accepted. Two of the three projects needed to be at least 100 tons, and the smallest accepted project size was 50 tons. That project-documentation requirement is important for any CGDIT upgrade review because the board needs enough detail to evaluate real design experience.

Historical Exam Format and Topics

The CGD handbook describes the examination as administered by AEE through remote proctoring. It was an open-book written exam, and all questions were mandatory. Question formats included multiple choice and true/false, with electronic grading. Candidates needed a 70% pass rate on the examination to meet the exam requirement.

These topics show the credential's practical focus: commercial geothermal heat pump design, not general HVAC vocabulary. Strong preparation meant being able to connect codes, project economics, loop-field decisions, piping design, soil behavior, installation constraints, diagnostics, and environmental concerns into defensible design decisions.

Documentation Checklist

If you are maintaining CGD status or exploring a CGDIT upgrade, start with documentation. Gather your AEE account information, certificate status, renewal deadline, professional development records, employment history, project summaries, training records, and any correspondence from AEE about legacy renewal-only eligibility. Do not rely on older third-party pages that still describe CGD as a normal new-applicant exam.

For project summaries, be specific. The handbook expects completed commercial geothermal heat pump design experience, and vague project descriptions can slow review. Record project size, system type, loop approach, role, design responsibilities, codes or standards used, software or calculations performed, and final project status. If your route depends on PE, RA, CEM, or degree status, keep that evidence in the same packet.

Readiness Guidance

Because AEE is no longer accepting new CGD applications, the main readiness question is administrative: are you renewing an active credential, upgrading from a current CGDIT, or mistakenly preparing for a closed new-candidate path? Answer that before spending time on study materials. A direct AEE confirmation is the cleanest way to avoid building a plan around outdated assumptions.

If you do need to review the historical exam scope for an upgrade or reinstatement discussion, build around commercial geothermal fundamentals. Revisit loop sizing, soil conductivity, piping systems, grout and installation choices, economic analysis, design software outputs, troubleshooting, environmental impact, and code constraints. Treat open-book materials as a design reference system, not a substitute for experience.