ACG CxA Exam 2025 | 100+ Questions | HVAC Commissioning, Retro-Cx, System Phases

This document provides a complete and updated collection of over 100 exam-style questions and verified answers for the ACG Commissioning Authority (CxA) Exam for the 2025/2026 academic year. It follows the official ACG guidelines and includes clear references to commissioning procedures, methodologies, and roles of team members involved in HVAC system commissioning for new construction, renovations, and existing facilities. Content is organized according to commissioning phases: Pre-design, Design, Construction, Acceptance, and Post-Acceptance. It thoroughly explains key processes in Comprehensive Commissioning, Construction HVAC Commissioning, and Retro/Re-Commissioning, aligned with ACG Chapters 5, 6, and 7. Topics include the scope and methodology of commissioning, functional performance testing (FPT), documentation standards, team structure (Plan & Spec vs. Design-Build), and CxA responsibilities. Additional focus is given to retro-commissioning in older buildings and commissioning considerations during renovations. This study guide is ideal for: Engineering students in HVAC, MEP, or Building Systems courses Construction management and project management students Professionals preparing for the ACG Certified Commissioning Authority (CxA) exam Facility managers or building engineers involved in energy efficiency and system performance verification With its structured, high-yield Q&A format, the document offers an efficient way to master commissioning concepts and pass the CxA certification exam confidently. Keywords: HVAC commissioning, commissioning authority, CxA exam prep, functional performance testing, construction phase, retro-commissioning, building systems, project phases, TAB agency, O&M training, system verification, building renovations, plan and spec, ACG guideline