Oklahoma HVACR Journeyman Unlimited

Oklahoma HVACR Journeyman Unlimited Exam: Complete 2026 Study Guide

Picture this: you've put in years learning the trade, working alongside experienced technicians, getting your hands dirty with refrigerant lines, ductwork, gas piping, and control boards. Now one exam stands between you and your Oklahoma HVACR Journeyman Unlimited license — the credential that opens doors to higher pay, better jobs, and the ability to work independently. This guide breaks down exactly what's on the exam, what to study, and how to prepare without wasting time. Start by taking our free practice exam to see where you stand right now.

Oklahoma HVACR Journeyman Unlimited Exam Overview

The Oklahoma HVACR Journeyman Unlimited exam consists of 70 scored questions, and you have 180 minutes to complete it. That works out to about 2.5 minutes per question — plenty of time if you're well-prepared, but tight if you're second-guessing yourself on unfamiliar material.

To pass, you need to answer at least 49 of 70 questions correctly — a 70% passing score. The exam is computer-based and multiple-choice, with four answer options per question.

The test covers six topic areas, weighted by item count:

• Air Distribution Systems — 16 items
• Refrigeration and Air Conditioning Systems — 16 items
• Electrical Knowledge and Controls — 15 items
• Natural Gas — 10 items
• Heating Systems — 10 items
• Safety — 3 items

Air distribution and refrigeration each carry the most weight, so those two areas deserve serious attention. That said, the Safety section is small but straightforward — don't leave easy points on the table.

Exam Topics: What You Need to Know

Air Distribution Systems (16 items)

This is the largest topic area. Expect questions on duct system configurations — radial, extended plenum, reducing trunk, perimeter loop, and SDHV systems. You'll also need to know duct materials (metal, fiberglass, flexible, ductboard), ACCA Manual D sizing principles, aspect ratio, and friction rate. Register, diffuser, and damper placement matters here, and so does duct sealing — mastic vs. metal tape, blower door testing, and duct blaster procedures.

Refrigeration and Air Conditioning Systems (16 items)

Know the compression refrigeration cycle cold. Compressor types (reciprocating, rotary, scroll, screw, centrifugal), metering devices (TXV, EEV, capillary tube, fixed orifice), evaporator and condenser construction, and defrost methods all appear on the exam. Refrigerant classification, ODP, GWP, and Clean Air Act compliance are fair game as well.

Electrical Knowledge and Controls (15 items)

This section tests your ability to read ladder and pictorial wiring diagrams, apply Ohm's law and Watt's law, and understand series, parallel, and series-parallel circuits. Single-phase and three-phase AC motors, starting methods, and relay types (current, potential, solid-state, PTC) round out this category.

Natural Gas (10 items)

You need to know approved piping materials (steel, copper, CSST, polyethylene), sizing methods (longest length, branch length, hybrid pressure), capacity tables, and pressure testing procedures. Combustion air requirements and venting systems — Type B, single-wall, chimney, direct-vent — are also covered.

Heating Systems (10 items)

This section spans gas-fired, oil-fired, hydronic, electric, and forced-air systems. Understand combustion, ignition systems, oil burner operation, boiler components, expansion tanks, and electric resistance heating elements.

Safety (3 items)

A small section but not a throwaway. LOTO procedures, fire extinguisher use (P.A.S.S. method and fire classes), refrigerant cylinder handling, PPE selection, and SDS/GHS labeling are all testable.

Sample Exam Questions

Here are five representative questions from the exam. Work through them — but we're not giving away the answers here. Try our free practice exam to check your reasoning.

Question 1 — Air Distribution Systems

When fuel-burning appliances such as furnaces and water heaters operate in a building, what effect do they tend to have on building air pressure?

A) They equalize indoor and outdoor pressures through the flue
B) They have no effect on building air pressure
C) They create a positive pressure by heating the air
D) They create a negative pressure by consuming indoor air for combustion and exhausting it outside

This question tests your understanding of combustion air dynamics — a concept that connects gas appliance operation to building pressure and venting system design.

Question 2 — Natural Gas

When using the branch length method for sizing gas piping, how is the initial piping segment from the meter sized?

A) Using only the length of the branch serving the highest-demand appliance
B) Using the distance from the meter to the furthest removed appliance
C) Using a standard 100-foot length for all segments
D) Using the actual length of each individual segment independently

Gas piping sizing questions require you to understand the distinctions between sizing methods — getting the method wrong on a real job means undersized pipe and starved appliances.

Question 3 — Air Distribution Systems

As a journeyman installing ductwork in a residential basement, you need to route branch ducts to diffuser openings. What is the common method for constructing return air branch ducts in a basement?

A) Using round spiral ductwork hung below the joists
B) Using the joists and floorboards as three sides of the duct (panned joist space)
C) Running flexible ductwork through the ceiling cavity above the joists
D) Installing ductboard between the floor joists

Field experience helps here, but you need to know the terminology and the logic behind why certain construction methods are used in specific applications.

Question 4 — Electrical Knowledge and Controls

A heating system has a cut-in temperature of 68°F and a cut-out temperature of 74°F. What is the system's differential?

A) 68°F
B) 74°F
C) 6°F
D) 3°F

Straightforward math — but only if you know what "differential" means in a controls context. These quick-calculation questions reward candidates who know their definitions.

Question 5 — Refrigeration and Air Conditioning Systems

As a journeyman HVACR technician, you need to braze a new filter-drier into a refrigerant line. Before applying heat, what gas should you flow through the inside of the tubing at low pressure (1–2 psi) to prevent oxide formation on the interior surfaces?

A) Refrigerant
B) Oxygen
C) Compressed air
D) Nitrogen

This is a practical technique question — the kind where real field experience and textbook knowledge converge. If you know why each option is right or wrong, you're in good shape.

What Types of Questions to Expect (By Topic)

Our practice question bank covers all six exam topics with 326 questions total. Here's what each topic area tests and how many practice questions we've built for it:

• Air Distribution Systems — 82 practice questions: Duct system design, material selection, Manual D sizing, aspect ratio, friction rate, register and diffuser placement, duct sealing methods, and leakage testing procedures.
• Refrigeration and Air Conditioning Systems — 73 practice questions: The full refrigeration cycle, compressor types and applications, metering device selection and operation, defrost systems, refrigerant properties, ODP/GWP, and environmental regulations.
• Electrical Knowledge and Controls — 57 practice questions: Diagram reading (ladder and pictorial), Ohm's law and Watt's law calculations, circuit types, motor starting methods, and relay types.
• Heating Systems — 53 practice questions: Gas combustion and ignition, oil burner operation and efficiency testing, hydronic system components, electric heating elements, and heat exchanger operation.
• Natural Gas — 46 practice questions: Pipe material selection, sizing method distinctions, capacity table use, pressure testing, combustion air calculations, and vent sizing.
• Safety — 15 practice questions: LOTO procedures, fire extinguisher classes and the P.A.S.S. method, refrigerant cylinder handling, PPE selection, and SDS/GHS label interpretation.

Study Materials for the Oklahoma HVACR Journeyman Exam

Using the right references makes a measurable difference. Here's what to have on hand:

International Mechanical Code 2024 (2018 edition accepted through December 13, 2026) — The IMC governs duct construction, equipment installation, and ventilation requirements. Air distribution questions often trace back to IMC provisions, so familiarity with this code is essential.

International Fuel Gas Code 2024 (2018 edition accepted through December 13, 2026) — The IFGC is your primary reference for gas piping materials, sizing methods, pressure testing, combustion air, and venting systems. If natural gas is a weak spot, this code is where you drill down.

Modern Refrigeration and Air Conditioning, 20th Edition — This is the industry-standard textbook for refrigeration theory and practice. Compressor types, refrigerant properties, the refrigeration cycle, metering devices — it's all here, explained clearly with diagrams.

Mathematics for Plumbers and Pipefitters, 8th Edition — Don't overlook the math side of the exam. Gas piping calculations, circuit math, and friction rate problems all require solid arithmetic. This book builds the foundation.

Work through relevant sections of each resource alongside your practice exams. Don't just read — apply the concepts to problems.

Study Tips for the Oklahoma HVACR Journeyman Unlimited Exam

Start with your weakest topic, not your strongest. It's tempting to review what you already know. Resist it. Spend the most time in the areas where you're dropping points.

Prioritize by exam weight. Air distribution and refrigeration each make up nearly a quarter of the exam. Master those first, then work through electrical, gas, and heating.

Use the practice exam strategically. Our free practice exam gives you 10 questions per attempt — a good way to get comfortable with the question style. When you're ready to simulate the real thing, the full practice exam matches the actual exam format: 70 questions, 180 minutes, broken down by topic so you can see exactly where you're strong and where you're not. Every attempt pulls from a large question pool, so you won't see the same exam twice.

Review incorrect answers thoroughly. Don't just note that you got something wrong — understand why the right answer is right and why the others aren't.

Time yourself. With 180 minutes for 70 questions, you have room to think. Practice under timed conditions so pacing feels natural on exam day.

Flag and move on. If a question has you stuck, mark it and come back. Don't burn five minutes on one item.

Frequently Asked Questions

How many questions are on the Oklahoma HVACR Journeyman Unlimited exam?
The exam has 70 scored questions. You have 180 minutes to complete it.

What is the passing score?
You need to answer 49 out of 70 questions correctly — a 70% passing score.

Which topics are most heavily weighted?
Air Distribution Systems and Refrigeration and Air Conditioning Systems each carry 16 exam items, making them the two largest topic areas. Electrical Knowledge and Controls follows at 15 items. Focus your preparation there first.

What study materials do I need?
The core references are the IMC 2024 (2018 edition accepted through December 13, 2026), the IFGC 2024 (2018 edition accepted through December 13, 2026), Modern Refrigeration and Air Conditioning, and Mathematics for Plumbers and Pipefitters. Pair those with targeted practice questions.

Is there a free way to practice before committing to a full study plan?
Yes. Our free practice exam gives you 10 questions per attempt with no account required. It's a solid first step to gauge your current knowledge level before deciding how much prep work you need.

Ready to Get Your Oklahoma HVACR Journeyman License?

The Oklahoma HVACR Journeyman Unlimited exam is thorough, but it's absolutely passable with focused preparation. You know this trade. The exam is testing whether your knowledge is organized and exam-ready — and that's something you can fix with the right study plan.

Start today: take the free practice exam, identify your gaps, grab the recommended references, and build from there. When you're ready to go deeper, upgrade to the full practice exam for a realistic simulation with detailed topic-by-topic feedback. Your license is closer than you think.