313A Exam Structure: Refrigeration and Air Conditioning
Explore the current 313A Red Seal question allocation, Ontario exam timing and passing grade, with original study exercises and clear distinctions from 313D and gas exams.
Ontario's 313A Refrigeration and Air Conditioning Systems Mechanic trade connects to the Red Seal Refrigeration and Air Conditioning Mechanic exam. Its scope includes residential, commercial, industrial and institutional systems. Skilled Trades Ontario: 313A trade information.
The currently published Red Seal outline contains 125 questions. They use four-choice multiple-choice questions with one correct response. Official refrigeration and air conditioning exam information.
Official information checked September 13, 2026. The study worksheets below are original preparation activities, not exam questions or equipment-service instructions.
Confirm that you are preparing for 313A
313D is the separate Ontario trade titled Residential Air Conditioning Systems Mechanic. Use its own exam resources when that is your target. STO: Residential Air Conditioning Systems Mechanic.
Similarly, this 313A outline does not describe TSSA G2 or G3 gas-technician exams. Do not transfer its question count or topic allocation to a gas certification pathway.
Write the exact trade title at the top of your notes. That small step helps you reject a study package whose title says only “HVAC exam” without identifying the intended qualification.
The current question allocation
The following table uses shortened activity labels from the published exam breakdown.
Major work activity | Questions out of 125 |
|---|---|
A — Shared occupational skills | 13 |
B — Routine trade work | 19 |
C — Installation planning | 18 |
D — Installation work | 26 |
E — Commissioning | 21 |
F — Maintenance and servicing | 28 |
Total | 125 |
The question-style ranges are 20–30% knowledge/recall, 50–60% procedural/application and 10–20% critical thinking. Red Seal 313A-equivalent exam outline.
As of the check date, the Red Seal trade landing page links a newer occupational standard but says exams based on it remain under development. This article uses the published information linked for current exams. Follow that distinction when choosing reference documents.
Use the system life cycle as a study organizer
A learner with extensive service experience may feel confident with a fault description but less comfortable with planning documentation. Another learner may remember installation topics yet struggle to explain what evidence supports a service conclusion.
Create four pages in your own notebook: planning, installation, commissioning, and maintenance/service. Use them to sort a few topics from your training materials. Keep a separate page for shared and routine skills so those parts of the outline remain visible.
For each topic, make three entries:
What information does a classroom problem supply?
What decision or result does it request?
Where can you verify the reasoning in your training references?
For example, a planning exercise might supply a drawing and a set of stated requirements. Your study task is to explain which information matters before attempting a calculation. You are rehearsing how to read a problem, not creating an installation specification.
Repeat the exercise with a commissioning record or a maintenance history from an authorized learning resource. Notice how the requested decision changes even when some components have familiar names.
An original evidence-sorting exercise
Imagine a fictional classroom worksheet containing one pressure reading and a short statement that a system is “not performing as expected.” The worksheet omits the equipment identity, measurement conditions and relevant reference information.
Can you justify a specific component replacement from that description?
Answer: no. The educational task is to identify the missing information, rather than invent a diagnosis. Write two columns: “provided” and “still needed.” Put only facts actually stated in the first column.
Next, compare this exercise with a complete practice question. A complete question may supply enough assumptions to support one answer. Explain how those assumptions narrow the possibilities. Avoid importing details from a different piece of equipment you remember from work.
Use the CodeSafe learning resources to rebuild concepts that make the reasoning difficult, then return to the relevant 313A preparation material.
Rehearse the pace you will need
STO's June 2026 guide specifies four hours and a 70% passing grade. It identifies paper or electronic delivery according to your exam confirmation. Ontario exam preparation guide.
For 125 questions, 240 minutes averages 1.92 minutes per question, or about 1 minute 55 seconds. A proportional 25-question practice segment takes 48 minutes including checking.
One rehearsal option is 40 minutes for the segment and eight for review. Record unanswered items and uncertain answers separately. A correct guess and a fully explained answer deserve different follow-up in your notebook.
Prepare the appointment as well as the topics
STO handles Ontario certifying-exam scheduling. Follow the eligibility and Authorization to Test process, and raise accommodation needs before booking. STO exam scheduling.
Keep your confirmation details with your study calendar. During your next study-plan session, choose a topic you can partly explain, complete one evidence-sorting exercise, and finish by writing what you will check next.