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Oklahoma HVACR Journeyman Limited — Practice Exam

What This Practice Exam Covers

The Oklahoma HVACR Journeyman Limited licensing exam is 60 questions answered in 180 minutes. A passing score is 70%, meaning you must answer at least 42 questions correctly. The exam spans six topic areas drawn from electrical controls, natural gas, air distribution, refrigeration, heating systems, and safety.

Two practice options are available here:

• Free practice exam: 10 questions per attempt, pulled from a limited pool. You can retake it as many times as you like at no cost — it is a useful first look at question style and format before you commit to serious prep.
• Full practice exam (paid): Mirrors the real exam exactly — 60 questions, 180-minute timer, same topic weighting. Questions are drawn from a pool of 330+ items based on the official exam blueprint, so every attempt produces a unique set. No two attempts will be identical, giving you genuine repeated-practice value.

Start with the free exam to get your bearings, then use the full exam for realistic timed rehearsal.

What You'll Be Tested On

Electrical Knowledge and Controls — 15 items

The heaviest topic on the exam. Expect calculations: Ohm's law (V = IR), Watt's law (P = IE), and — critically — Minimum Circuit Ampacity (MCA) and Maximum Overcurrent Protection (MOCP) using NEC formulas. You must know how to read both pictorial and ladder diagrams to trace current paths and identify component states.

Motor questions cover split-phase, shaded-pole, permanent split capacitor (PSC), capacitor-start induction-run (CSIR), and capacitor-start capacitor-run (CSCR) motors — their construction, starting torque, and capacitor roles (Chapter 15, Section 15.2.1). You also need the four motor starting relay types: current relays, potential relays, solid-state relays, and PTC relays (Chapter 16, Section 16.3.5), including which conditions each relay responds to.

Pressure and temperature motor controls (Chapter 16, Section 16.3.4) require you to distinguish cut-in vs. cut-out set points, range, and differential — and to know whether adjusting the range screw or differential screw moves one set point or both. Motor protection — fuses, circuit breakers, bimetal overloads, and thermistor overloads — rounds out this section (Chapter 16, Sections 16.4.1–16.4.3).

Natural Gas — 9 items

Questions test allowable piping materials (steel, copper, CSST, PE) and fittings under the 2021 International Fuel Gas Code. Sizing questions reference the longest-length, branch-length, and hybrid pressure methods — you must know when each applies and how to read capacity tables (IFGC 2021, pages 4-1 and 4-2).

Pressure requirements, testing procedures, and leak-check methods are tested directly — know the pressure differential for low-pressure systems and what constitutes an acceptable test (IFGC 2021, pages 4-45, Sections 406.4.1 and 406.4.2). Combustion air calculations — confined vs. unconfined spaces, indoor air openings, outdoor air methods — appear alongside venting category selection (Categories I–IV, Type B, single-wall, direct-vent) for matching appliance type to vent type (IFGC 2021, pages 5-1 to 5-2).

Air Distribution Systems — 10 items

Know the five system configurations: radial, extended plenum, reducing trunk, perimeter loop, and SDHV. Duct sizing per ACCA Manual D requires understanding friction rate, equivalent length, and target velocity ranges — residential supply trunks typically run 600–900 FPM.

Register, diffuser, and grille selection questions focus on throw, spread, and placement relative to the conditioned space. Damper questions cover butterfly, multiple-blade, split, fire, and smoke dampers — including automatic control and installation requirements (IMC 2021, Section 603.18 and 603.18.1). Duct insulation and vapor retarder requirements appear under IMC 2021, Section 604.3. Airflow measurement tools — flow hoods, manometers, pitot tubes, blower door, and duct blaster — are tested both on what they measure and how they are used.

Refrigeration and Air Conditioning Systems — 13 items

The second-heaviest topic. The compression refrigeration cycle must be understood component by component, with refrigerant state (pressure, temperature, phase) at each point. Refrigerant classification — ASHRAE safety groups, GWP, ODP, flammability — and EPA/Clean Air Act obligations for handling, recovery, and venting prohibition are tested.

Metering device behavior is a high-yield area: capillary tubes (fixed restriction), TXVs (superheat-sensing), AXVs, EEVs, and fixed-orifice devices — know what each controls and how it responds to load changes. Recovery, recycling, and reclaiming are distinct procedures with specific equipment requirements. Compressor types (reciprocating, scroll, rotary, screw) and their protective components (high-pressure cutout, low-pressure cutout, motor overload) are covered in Modern Refrigeration and Air Conditioning, Chapter 18.

Heating Systems — 10 items

Gas-fired systems require knowledge of burner types, ignition systems (standing pilot, HSI, intermittent pilot), and combustion safety controls. Oil-fired systems test burner components, fuel delivery (nozzle sizing, pump pressure), and combustion efficiency testing using a stack thermometer and CO₂/O₂ analysis (Modern Refrigeration and Air Conditioning, Oil-Fired Heating Systems, page 1183).

Hydronic systems test boilers, circulating pumps, expansion tanks (plain vs. bladder type), zone valves, and terminal units. Heat pump questions focus on reversing valve operation — which port connects where in heating vs. cooling mode — and how metering device selection differs for heat pump applications. Electric resistance heating covers duct heaters, baseboard units, and radiant panels. Hydronic design configurations — series loop, one-pipe, two-pipe, zoned, and radiant — each carry distinct balancing and flow characteristics.

Safety — 3 items

Three questions, but they are straightforward points to lock in. Know LOTO procedures step by step (HVACR Textbook, Chapter 2, Section 2.2.1), the P.A.S.S. sequence for fire extinguisher use (Chapter 2, Section 2.2.2), refrigerant cylinder handling rules (Chapter 2, Section 2.2.4), GHS labeling elements and SDS sections (Chapter 2, Section 2.2.6), and respiratory protection selection (Chapter 2, Section 2.3.4). PPE questions may ask which specific protection — gloves, goggles, face shield — applies to a given task.

Worked Sample Questions

Question 1 — Electrical Knowledge and Controls

An A/C condensing unit has Compressor FLA 28A, Fan 3A, MOCP 50A. What is the calculated MCA?
A. 31A | B. 38A | C. 40A | D. 43A

Correct answer: B — 38A

MCA is calculated as 125% of the largest motor's FLA plus the FLA of all other loads:

(28 × 1.25) + 3 = 35 + 3 = 38A

The 1.25 multiplier applies to the largest motor (the compressor). The fan FLA is added at 100%. The MOCP value of 50A is a separate rating and is not used in the MCA formula. Mixing these two values is the most common error on this question type.

Question 2 — Refrigeration and Air Conditioning Systems

A rooftop unit on a 90°F day has normal suction but high head pressure. Coil is clean, charge verified. What is the cause?
A. Low airflow | B. Dirty filter | C. Non-condensables | D. TXV malfunction

Correct answer: C — Non-condensables

Non-condensable gases (air, nitrogen) in the refrigerant circuit collect in the condenser and raise head pressure without affecting suction pressure. Low airflow or a dirty filter would also raise head pressure, but these are ruled out by the question stem (coil clean, charge verified). TXV malfunction would typically affect suction pressure. When you see high head + normal suction on a verified, clean system, non-condensables are the textbook answer.

Question 3 — Air Distribution Systems

A trunk carries 1,200 CFM. What is typical velocity per Manual D?
A. 400–600 FPM | B. 600–900 FPM | C. 1,000–1,400 FPM | D. 1,600–2,000 FPM

Correct answer: B — 600–900 FPM

ACCA Manual D targets residential supply trunks in the 600–900 FPM range, with approximately 900 FPM as a practical upper limit to control noise. Velocities in range C or D are appropriate for commercial systems or small high-velocity ductwork — not standard residential trunk sizing. Candidates who confuse residential and commercial velocity targets consistently miss this question.

How to Read Your Score

The passing threshold is 70% — 42 correct out of 60 questions. On the full practice exam, treat your first score as a diagnostic snapshot, not a final verdict. A first attempt tells you where your knowledge is solid and where it has gaps; it does not predict your exam day performance on its own.

Use the topic breakdown your score report provides. If you score below 70% overall, check whether the shortfall is concentrated — a weak score in Electrical (15 items) or Refrigeration (13 items) will drag your total much more than weakness in Safety (3 items). Prioritize high-item topics first.

Be honest with yourself about scores near the cutoff. Passing practice at 72% with unfamiliar questions still ahead is not a comfortable margin — a few hard refrigerant calculation questions or an unfamiliar venting category question can close that gap quickly. Aim for consistent 80%+ across multiple full attempts before exam day. Because the full practice pool contains 330+ questions, retaking the exam gives you genuine new exposure rather than memorized answers.

Where Candidates Lose Points

MCA/MOCP calculation errors are the single biggest electrical point-loser. Candidates apply the 1.25 multiplier to the wrong motor, or confuse MCA with MOCP. Write the formula before picking up your pencil.

Pressure control differential vs. range confusion catches candidates who have not worked with actual pressure controls. Know that adjusting the range screw shifts both cut-in and cut-out, while the differential screw changes only the gap between them (Chapter 16, Section 16.3.4).

Gas piping sizing method selection — longest-length vs. branch-length — trips candidates who apply the wrong table to the scenario. Read whether the question specifies a single appliance or a multi-branch system.

Venting category misidentification is a consistent natural gas error. Candidates assign Type B vent to a Category IV condensing appliance, or allow single-wall vent where it is not permitted. Know the four appliance categories and their permitted vent types cold (IFGC 2021, pages 5-1 to 5-2).

Non-condensables vs. overcharge on refrigeration diagnostics: both raise head pressure, but overcharge also raises suction pressure. Missing that distinction costs points on scenario-style refrigeration questions.

Time management on the electrical and refrigeration sections — combined, they are 28 of 60 questions. Candidates who spend too long on calculation questions run short on the heating and air distribution sections, which have straightforward questions they could have answered quickly.

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