Idaho HVAC Journeyman Exam

Idaho HVAC Journeyman Exam: Complete Prep Guide for 2026

You know the trade. You've pulled the wire, hung the ductwork, brazed the line sets. The Idaho HVAC Journeyman Exam asks something different: can you find the rule in the code book and read it right, under time pressure. That's a skill you build on purpose.

This guide lays out what the exam covers, how the items are spread across the 2018 IMC and 2018 IFGC, what the questions look like, and how to study so you walk in ready.

Idaho HVAC Journeyman Exam Overview

The exam is delivered by PSI. It is an open-book exam built on the 2018 International Mechanical Code and the 2018 International Fuel Gas Code. Open book does not mean easy. It means you have to practice finding specific numbers, specific tables and specific exceptions fast — the kind of detail nobody carries in their head.

Check the licensing agency website for the application side, the official bulletin for the exam rules, and exam registration when you're ready to book a seat.

Here are the exam's core facts:

On exam day

• You must present one current, government-issued photo and signature ID (such as a driver's license, state ID card, passport, military ID, or alien registration card) to be admitted.
• Arrive 15 minutes before your appointment time.
• Candidates must bring their own approved references, may not write in them during the exam, and may not have additional papers or temporary markers, which will be confiscated.
• Pre-exam highlighting, underlining, and permanent indexing are permitted, but temporary markers such as Post-its are prohibited and no writing is allowed during the exam.
• Only approved items may be brought into the exam room; all other personal belongings, including electronics, writing devices, bags, food and drinks, must be placed in secure storage.

References you may bring

• International Mechanical Code (IMC), ISBN-13: 9781609837433 (2018)
• International Fuel Gas Code (IFGC), ISBN-13: 9781609837419 (2018)

Scheduling, changes and retakes

• You may schedule online through PSI's registration website or by calling PSI at 855-340-3713.
• You may cancel and reschedule without forfeiting your fee if PSI receives your cancellation notice 2 days before the scheduled examination date, done by website or by phone (not voicemail or email).
• If you miss your appointment, arrive after the examination start time, cancel late, or lack proper ID, your registration is invalid and you forfeit your examination fee.
• Your score is shown on screen at the end of the exam and a score report is provided, with a diagnostic report of strengths and weaknesses if you fail.
• If you do not pass, you may retake the exam as many times as needed, paying an examination fee for each attempt.

Source: Examination Scheduling Procedures / Examination Guide (Idaho PSI Candidate Bulletin), Effective 7/9/2026. Check the bulletin before test day: fees and rules can change.

Exam Topics and Content Breakdown

The exam has 100 questions. Roughly two-thirds come from the IMC and one-third from the IFGC. Here is the breakdown, heaviest first.

IMC Chapter 3 (9 items, 9%). The biggest single block. Expect attic passageway limits — length, height, and width, including the exception that lets you go longer. Expect prohibited combustion air sources and when a furnace in a closet is allowed. Expect the minimum clearance above the floor for appliances in private garages and carports, and the minimum indoor temperature a space-heating system must be able to hold, measured at a stated height above the floor.

IMC Chapter 5 — Exhaust Systems (9 items, 9%). Dryer exhaust: maximum duct length, the equivalent-length deductions in Table 504.8.4.1, and the required open area at the terminal. Also covered: screen and louver opening sizes at outdoor exhaust terminations, minimum separation from exhaust outlets carrying flammable vapors to operable openings, and air changes per hour for limited spraying spaces.

IFGC Chapter 5 — Chimneys and Vents (8 items, 8%). Vent termination height above the highest connected draft hood or flue collar. Minimum sheet steel thickness for single-wall metal pipe. Test pressure and duration for plastic vent pipe inside a dwelling. Direct-vent terminal clearances from Table 503.8 by input rating. Aggregate input limits for unvented appliances before venting is required.

IMC Chapter 2 — Definitions (7 items, 7%). Definitions carry real weight. Know refrigerant flammability classes, how the code handles terms not defined in the IMC, and how to treat terms not defined anywhere in the I-Codes.

IFGC Chapter 4 — Gas Piping Installation (7 items, 7%). Adding an appliance to an existing system and what happens when capacity falls short. Labeling intervals for exposed non-steel gas piping. LP storage system standards. Whether separate consumers' piping may be interconnected downstream of the meters.

IFGC Chapter 3 — General Regulations (6 items, 6%). Combustion air by the standard indoor method, cubic feet per 1,000 Btu/h. Free area per Btu/h for the two-permanent-openings method with horizontal ducts. Minimum internal diameter for condensate drain lines. Input limits for an unvented room heater in a bathroom.

Five-item topics. IMC Chapter 4 (ventilation): minimum openable area for natural ventilation, intake separation from contaminant sources, pool-area recirculation limits. IMC Chapter 11 (refrigeration): open-flame devices in refrigerant rooms, refrigerant change notification thresholds, piping height over passageways, relief device termination heights. IMC Chapter 12 (hydronics): hydrostatic test pressure and duration, thermal breaks at heated slabs, clearance for hot pipe, flame spread and smoke-developed indexes for pipe insulation. IFGC Chapter 6 (specific appliances): unit heater clearances, unvented room heater input limits, direct-fired industrial air heater ventilation rates. IFGC Chapter 7 (hydrogen): purging sequence, exposed joints during testing, hydrostatic test pressure, system definition.

Four-item topics. IMC Chapter 1 (administration): general versus specific requirements, permit exemptions, application abandonment, the three required inspections. IMC Chapter 6 (duct systems): corridor return air exception, fastening round duct, crimp joint lap and direction, smoke detector thresholds. IMC Chapter 8 (chimneys and vents): mechanical draft termination clearances, vent height above flue collar, single-wall connector horizontal length, connector clearances. IMC Chapter 13 (fuel oil): valves on return piping, relief valves on pump discharge, solder melting point, nonmetallic pipe location.

Three-item topics. IMC Chapter 9 (specific appliances), IMC Chapter 10 (boilers and pressure vessels), IFGC Chapter 1 (administration), IFGC Chapter 2 (definitions).

One-item topic. IMC Chapter 14 (solar thermal) — one item, but it can still be the difference. Storage tank R-value, drain-back slope, and heat transfer fluid flash point all show up in practice.

Sample Questions from the Idaho HVAC Journeyman Course

Three practice questions. No answers here — work them with your code books open, then test yourself on more questions in the free practice exam, which gives you 10 questions.

1. When designing a smoke control system using the pressurization method, what is the maximum allowable leakage area ratio (A/Aw) for interior exit stairways, ramps, and exit passageways through smoke barriers?

A. 0.00150
B. 0.00100
C. 0.00050
D. 0.00035

Tests a lookup in the IMC smoke control provisions. Pure book work — you either find the ratio or you don't.

2. Where a vent insulation shield passes through attic space, the shield must terminate not less than how many inches above the insulation materials?

A. 6 inches
B. 2 inches
C. 1 inch
D. 4 inches

Tests an IFGC venting detail that's easy to blow past on the job site and easy to find in the book if you know where to look.

3. Properly charged 5-ton system struggles at 100°F outdoor. Cause?

A. Oversized compressor
B. Undersized TXV
C. Partially fouled condenser
D. Indoor blower speed fault

Tests field diagnosis when the charge is ruled out.

What Types of Questions to Expect

Three shapes show up on the Idaho HVAC journeyman practice test.

Straight lookups. "What is the minimum clearance above the floor for appliances located in private garages and carports?" One number, one code section. These are the fastest points available.

Scenario questions. You get a job situation — a 25-foot attic passageway that's 5 feet high and 24 inches wide — and you have to decide whether it complies and say why. These punish partial knowledge. You need the base rule and the exception, because a wrong answer can be built out of the exception applied badly.

Calculation questions. Duct velocity from CFM and diameter. MCA from compressor FLA and fan amps. Equivalent length deductions subtracted from a maximum dryer duct run. Know the formulas cold.

You'll also see true/false items, and some questions hinge on a single qualifier — "not less than," "not more than," "except." Read those words twice.

Essential Study Materials for Your Idaho HVAC License

Get the right books and set them up before you study, not the week of the exam.

• 2018 International Mechanical Code (IMC) — required. Most of the exam lives in this book. Get the 2018 edition, not a newer one.
• 2018 International Fuel Gas Code (IFGC) — required. Gas piping, venting, combustion air, hydrogen systems. Roughly a third of the exam.
• Redi-Tag Permanent White Tabs — 375 laser-printable divider tabs for building your own index. Tab every chapter and every table you keep returning to. They don't tear or curl.
• Sharpie Highlighters — 12 assorted colors with narrow chisel tips. Color-code by chapter or by type of rule: clearances one color, test pressures another.

The exam is open book, so practice finding rules quickly. Let the highlighter ink dry before you go over it again.

Study Tips for Idaho HVAC Journeyman Success

Weight your study time by item count. IMC Chapter 3 and IMC Chapter 5 together are the largest chunk of the exam. IFGC Chapter 5 is close behind. Spend your hours there. Don't burn a whole evening on solar thermal.

Build the index before you study, not after. Tab your chapters. Tab the tables by name. Then use those tabs every single time you look something up during practice. By exam day you should know where each rule lives without thinking.

Practice the lookup, not the memorization. Open book changes the game. You're not memorizing every clearance — you're training the path from question wording to the right page. When you miss a practice question, write down where the answer lived, not just what it was.

Learn the exceptions. Some scenario questions turn on an exception. When you highlight a rule, highlight its exception in a different color right next to it.

Watch your pace. You have 4 hours for 100 questions, which works out to about 2 minutes 24 seconds per question. Straight lookups should take well under that so you bank time for the scenarios and calculations. If a question stalls you, mark it and move. Come back with your leftover time.

Take a full-length run. An Idaho HVAC journeyman practice test at full length, timed, with your actual tabbed books, tells you more than a week of reading. Our practice exam gives you 100 questions.

Know the pass mark and aim well above it. You need a minimum score of 70. Build margin so a couple of surprises don't sink you.

Take the Next Step Toward Your Idaho HVAC License

The Journeyman HVAC exam rewards preparation you can actually do: get the two code books, tab them, and put in reps looking things up under a clock.

Start with the free practice exam to find your weak chapters. From there, our Idaho HVAC journeyman course walks the full outline with explanations and code citations, so you learn the rule and where it lives.

Register when you're ready at PSI, and check dopl.idaho.gov for the licensing steps that follow the exam.