313A Red Seal — Refrigeration & AC Mechanic

About the 313A Red Seal Exam — Refrigeration & AC Mechanic

The 313A Refrigeration and Air Conditioning Mechanic Red Seal exam is the interprovincial exam for technicians who install, maintain and service commercial and industrial refrigeration systems, HVAC equipment and process cooling. Job Bank projects a strong risk of labour shortage for refrigeration and air conditioning mechanics nationally over 2024–2033.

The exam consists of 125 multiple-choice questions and requires a minimum score of 70%. The new version, aligned to the 2024 Red Seal Occupational Standard (RSOS), has been active in British Columbia since June 22, 2026, and Alberta's counselling sheet dated August 5, 2026 shows the same new breakdown (checked September 2026). Exam time is 4 hours.

Official 313A Exam Breakdown (2024 standard)

On the new 313A exam, aligned to the 2024 Red Seal Occupational Standard, the 125 questions are spread across the Major Work Activities like this:

• A — Performs common occupational skills — 10 questions
• B — Performs routine trade activities — 20 questions
• C — Plans installation — 16 questions
• D — Performs installation — 26 questions
• E — Performs commissioning — 22 questions
• F — Performs maintenance and service — 31 questions

Every question is four-option multiple choice with one correct answer, the writing time is four hours and the pass mark is 70%. Sources: SkilledTradesBC Red Seal exam breakdown (new exam active as of June 22, 2026) and the Alberta Apprenticeship and Industry Training counselling sheet dated August 5, 2026 (checked September 2026). The red-seal.ca exam information page shows the split of the exam based on the previous standard (13/19/18/26/21/28), which red-seal.ca labels the occupational standard for current exams. Before you book, confirm with your apprenticeship authority which version you will write.

What this question bank covers

These are the topic areas in this practice bank and what each one covers. The real 313A exam has 125 questions and a four-hour writing time. How those questions are distributed across the official blocks is published by Red Seal — see the 313A exam information page.

• Refrigeration Theory & Cycle Analysis — Vapour-compression cycle (evaporation, compression, condensation, expansion), P-H diagrams (Mollier charts), subcooling and superheat calculations, COP and system efficiency. Practise reading a P-H diagram and diagnosing system performance from it.
• Refrigerants & Environmental Regulations — Refrigerant properties (R-404A, R-410A, R-134a, R-744 CO₂, R-290 propane, low-GWP alternatives), HCFC phase-out schedules, Environment and Climate Change Canada (ECCC) regulations, refrigerant recovery and handling, and leak detection methods.
• Compressors — Reciprocating, scroll, screw, and centrifugal compressor operation, capacity control, valve diagnostics, oil management, and failure analysis. Suction and discharge pressure relationships.
• Electrical Controls & Automation — Ladder logic, sequencing controls, solid-state relays, VFDs for compressors and fans, DDC/BAS system integration, pressure and temperature controllers, and safety control circuit testing.
• Condensers, Evaporators & Heat Transfer — Air-cooled and water-cooled condensers, cooling tower operation, evaporative condensers, direct-expansion and flooded evaporator circuits, defrost methods (electric, hot gas, off-cycle).
• Piping, System Installation & Safety — CSA B52 Mechanical Refrigeration Code, pipe sizing, pressure testing, nitrogen purging, refrigerant charge verification, and machine room requirements.

Exam Strategy for 313A

Master the P-H diagram. Practice plotting a complete cycle, identifying subcooling and superheat zones, and diagnosing abnormal conditions (high discharge temp, liquid slugging, flash gas in the liquid line).

Know the current refrigerants. Understand the low-GWP refrigerants (R-32, R-454B, R-744): flammability classification (R-32 and R-454B are A2L), pressure behaviour, and oil compatibility.

Study electrical controls. Practice reading ladder logic diagrams, VFD parameters, and DDC setpoints.

How to Use This Practice Tool

This tool includes 115 questions grouped by this site's own topic areas (not one-to-one with the official Major Work Activities), with full answer explanations. Filter by topic to drill refrigeration cycle calculations, refrigerant properties, or any area where your scores are low. Use Mock Exam Mode to practice under timed conditions.

Related reading: How to Pass the 313A Red Seal Exam | 313A Salary Guide | 313A Career Guide