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Oklahoma HVACR Journeyman Unlimited — Practice Exam

What This Practice Exam Covers

The Oklahoma HVACR Journeyman Unlimited licensing exam consists of 70 questions with a 180-minute time limit. You need a 70% score (49 correct) to pass. The exam spans six technical topic areas, from electrical fundamentals and refrigeration systems to gas codes and safety protocols.

Two practice options are available here:

• Free practice exam: 10 questions per attempt, drawn from a limited pool. You can retake it as many times as you like — useful for getting comfortable with the question format and pacing before committing to serious prep.
• Full practice exam (paid): Mirrors the real exam exactly — 70 questions, 180-minute timer, six topic areas weighted as they appear on the official exam. Questions are drawn from a pool of 326+ items, so each attempt delivers a unique mix. No two sessions are identical, which means repeated attempts keep building your knowledge rather than training you on memorized answers.

Start with the free exam to get your bearings, then use the full exam for focused preparation.

What You'll Be Tested On

Electrical Knowledge and Controls — 15 items

The heaviest electrical content on this exam. Expect to read and interpret both pictorial and ladder wiring diagrams — you must trace circuits under real service conditions, not just identify component symbols. Ohm's law and Watt's law questions require actual calculation: voltage, current, resistance, and power from partial information. You must know how series, parallel, and series-parallel circuits behave differently — total resistance, current paths, and voltage drops.

Motor questions are detailed. You need to distinguish split-phase, shaded-pole, PSC, capacitor-start induction-run, and capacitor-start capacitor-run motor types (Chapter 15, Section 15.2.1 covers each separately). Starting relays are tested individually: current relays, potential relays, solid-state relays, and PTC relays each have distinct operating principles you must know (Chapter 16, Section 16.3.5). Motor protection — fuses, circuit breakers, and bimetal overloads — appears alongside NEC 440.22 overcurrent protection calculations.

Natural Gas — 10 items

Gas piping material selection matters here: steel, copper, CSST, and polyethylene each have code-specific applications under the International Fuel Gas Code 2021. Sizing methods — longest length, branch length, and hybrid pressure — require you to use capacity tables correctly (IFGC 2021, Page 4-2, Section 402.4.1 and Section 402.4.3). Pressure testing and leak-check procedures are tested, including test duration and acceptable pressure drop limits (IFGC 2021, Page 4-45, Sections 406.4.1 and 406.4.2).

Combustion air requirements — indoor, outdoor, and combined methods — are code-specific (IFGC 2021, Pages 3-6 through 3-8). Venting system types (Type B, single-wall, chimney, direct-vent) require you to know application limits and sizing rules (IFGC 2021, Section 503 series). Gas furnace components — gas valves, burners, ignition systems (hot surface, spark, pilot), and safety controls — round out this section.

Air Distribution Systems — 16 items

Tied with Refrigeration as the heaviest single topic. Duct system configurations — radial, extended plenum, reducing trunk, perimeter loop, and SDHV — must be distinguished by design purpose and application. Construction materials include metallic, fiberglass ductboard, and flexible duct, each with specific joining and sealing requirements (IMC 2021, Page 6-4, Section 603.2 and Section 603.4.1).

Duct sizing follows ACCA Manual D principles: friction rate selection, aspect ratio limits, and equivalent length calculations. Register, diffuser, and grille selection affects throw and room air distribution — placement questions appear. Duct leakage testing using blower door and duct blaster equipment is tested, as are mastic and metal tape sealing methods (IMC 2021, Page 6-6, Sections 603.18 and 603.18.1). Ventilation calculations including air changes per hour appear here.

Refrigeration and Air Conditioning Systems — 16 items

The full compression refrigeration cycle — from evaporator through compressor, condenser, and metering device — must be understood in operating sequence. Compressor types (reciprocating, rotary, scroll, screw, centrifugal) have distinct mechanical characteristics tested separately (Modern Refrigeration and Air Conditioning, Chapter 18).

Metering devices — capillary tube, TXV, AXV, EEV, and fixed orifice — differ in how they respond to load changes; you must know which is which. Refrigerant classification, ODP and GWP values, and Clean Air Act Section 608 requirements for handling regulated substances appear explicitly. Charging procedure questions test your ability to calculate and interpret superheat and subcooling values. Evacuation target levels and recovery equipment requirements are also tested.

Heating Systems — 10 items

Gas-fired systems overlap with the Natural Gas topic but focus here on combustion efficiency, heat exchanger operation, and furnace sequencing. Oil-fired systems require knowledge of fuel oil grades, oil burner components, and combustion analysis (Modern Refrigeration and Air Conditioning, Oil-Fired Heating Systems, Page 1183). Hydronic systems — boilers, circulating pumps, expansion tanks, and terminal units — are tested as complete systems.

Electric heating covers resistance elements, electric furnaces, duct heaters, and baseboard units. Heat loss calculations using R-values, U-values, and design temperatures are applied math questions — not conceptual.

Safety — 3 items

Three questions, but missing any one of them hurts. Lockout/tagout procedures, fire extinguisher selection using the P.A.S.S. method and fire class identification, refrigerant cylinder handling and pressure hazards (HVACR Textbook, Chapter 2, Section 2.2.4), SDS and GHS labeling elements (Chapter 2, Section 2.2.6), and respirator selection — air-purifying vs. supplied-air — (Chapter 2, Section 2.3.4) are all fair game.

Worked Sample Questions

Question 1 — Air Distribution Systems

An air handler is delivering 1,200 CFM through a 16" round duct. What is the approximate air velocity?

• A. 500 FPM
• B. 650 FPM
• C. 800 FPM
• D. 1,000 FPM

Correct Answer: C — 800 FPM

A 16" round duct has a radius of 8 inches (0.667 ft). Area = π × r² = 3.1416 × 0.444 ≈ 1.396 sq ft. Velocity = CFM ÷ Area = 1,200 ÷ 1.396 ≈ 860 FPM. Among the options, 800 FPM is the closest. The exam tests this calculation repeatedly — memorize that a 16" duct is approximately 1.4 sq ft of area and you can solve it in seconds.

Question 2 — Refrigeration and Air Conditioning Systems

When evacuating an HVAC system, the target vacuum should reach:

• A. 250 microns
• B. 500 microns
• C. 1,000 microns
• D. 2,000 microns

Correct Answer: B — 500 microns

Industry-standard deep vacuum target before refrigerant charging is 500 microns. Pulling below 500 microns confirms that non-condensables and moisture have been removed adequately. A reading that rises quickly after the vacuum pump is isolated indicates a leak or remaining moisture — the system is not ready for charge. Know this number cold.

Question 3 — Electrical Knowledge and Controls

An A/C unit has a compressor rated at 20A and a condenser fan rated at 3A. What is the maximum OCPD per NEC 440.22?

• A. 40A
• B. 45A
• C. 50A
• D. 60A

Correct Answer: A — 40A

NEC 440.22 sets the maximum overcurrent protection for motor-compressor circuits. The calculation: (20 + 3) × 175% = 23 × 1.75 = 40.25A. Because this is a maximum, you must select the largest standard OCPD size that does not exceed 40.25A — which is 40A. Choosing 45A or 50A violates the code's intent even though those are standard sizes. The exam tests whether you know the multiplier and the rounding direction.

How to Read Your Score

The passing threshold is 70% — 49 correct out of 70 questions. On your first full practice attempt, treat your score as a diagnostic, not a verdict. A first-attempt score in the 55–65% range is common for working technicians who know the trade but haven't studied code-specific details. It tells you where to focus, not whether you'll pass.

Use a topic-by-topic breakdown after each attempt. If you're scoring 80%+ on Refrigeration but 50% on Natural Gas, those IFGC code sections need dedicated review time — not another session on refrigerant properties you already know. Air Distribution Systems and Electrical each carry 15–16 items, so a weak score in either area alone can pull you below passing.

Scoring 68–72% on practice should not be taken as exam-ready. That margin is narrow enough that test-day nerves, unfamiliar phrasing, or one bad calculation can push you below the line. Aim to hit 78–80% consistently on full practice exams before scheduling. Because the 326+ question pool means each attempt is genuinely different, repeated attempts reflect real knowledge, not pattern memorization.

Where Candidates Lose Points

Unit errors kill electrical calculations. Candidates convert inches to feet incorrectly in duct area problems, or mix up watts and kilowatts in Watt's law questions. Write out your units at every step.

Wrong multiplier on NEC 440.22. Many candidates use 225% or 150% instead of 175%, or apply the correct multiplier but then round up to the next standard OCPD size — which is exactly wrong. The rule is maximum, meaning round down.

Gas piping sizing table selection. The IFGC provides separate capacity tables for different pressure ranges and pipe materials. Picking the steel-pipe table for a CSST run, or using the wrong pressure column, produces a wrong pipe size even with correct math.

Skipping combustion air calculation steps. The combined indoor/outdoor combustion air method has sequential requirements — candidates who memorize one method apply it universally and miss questions on the other.

Refrigerant handling procedure sequencing. Recovery, evacuation, and charging each have specific equipment requirements and sequence steps. Questions that describe a partially completed procedure and ask "what's next" catch candidates who know the steps but not the order.

Running out of time on the heavy sections. With 70 questions in 180 minutes, you have about 2.5 minutes per question. Air Distribution (16 items) and Refrigeration (16 items) together account for nearly half the exam. Candidates who spend 5+ minutes on complex duct sizing problems leave themselves no buffer for Safety and Heating questions they could answer quickly.

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