HVAC / Mechanical Contractor License Exam Guide (2026)

The HVAC and mechanical contractor exam covers four overlapping bodies of code and reference material: the International Mechanical Code (IMC) for duct, ventilation, and combustion appliances; the International Fuel Gas Code (IFGC) for gas piping and venting; ASHRAE 62.1 and 62.2 for ventilation rates; and the IECC for envelope, equipment efficiency, and commissioning. Some states (notably Florida, Texas, and Louisiana) also test refrigeration cycle theory and EPA Section 608 refrigerant handling. Plan your study around the code your state has adopted.

~80 questionstypical exam length
4 hourstime limit (varies by state)
70% to passtypical scaled score

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HVAC licensing - state, municipal, and EPA layers

About 30 states license HVAC or mechanical contractors at the state level. Several large states (Texas, Florida, North Carolina) have classified subdivisions - Class A vs. Class B by tonnage, RMP vs. journeyman, and so on. The remaining states rely on city or county licensing. On top of that, every HVAC technician who handles refrigerant must hold a federal EPA Section 608 certification - separate from the state contractor license. Pick your state below for the exact tier structure, tonnage thresholds, and supervising-mechanic requirements.

Approved code books and references

Every HVAC / mechanical contractor exam is open-book with state-approved references. The primary reference is the International Mechanical Code (IMC) plus the IFGC and ASHRAE 62; supplementary references vary by state.

IMC (International Mechanical Code) - duct sizing, ventilation, combustion air, chimneys
IFGC (International Fuel Gas Code) - fuel gas piping, appliance venting, combustion-air supply
ASHRAE 62.1 / 62.2 - ventilation rate procedure for commercial and residential buildings
IECC - envelope, equipment efficiency, ductwork insulation, and commissioning
OSHA 1926 - fall protection on rooftop equipment and crane lifts for AHUs

Confirm the exact editions in your state's current candidate information bulletin - states usually lag the newest code cycle by one or two editions. Our code-book tabbing guide walks through how to set up tabs so you can hit a section in under 30 seconds under exam pressure.

What the HVAC / Mechanical contractor exam tests

Load calculations and Manual J / N. Block load vs. room-by-room calculations, sensible and latent split, internal gain assumptions. About 10-15 percent of the exam relies on you being able to read a load calc and verify equipment selection.
Duct sizing and static pressure. Friction-rate method, equivalent length penalties for fittings, CFM-per-square-foot delivery, and static pressure budgeting through filters, coils, and registers.
Combustion air and venting. Category I through IV appliance venting, makeup-air sizing, draft-hood vs. direct-vent rules, and combined venting per the IFGC.
Refrigeration cycle and refrigerant handling. Superheat, subcooling, charging methods, leak detection, and EPA Section 608 record-keeping. R-410A phasedown and R-32 / R-454B transition rules are now exam-relevant.
Ventilation rates (ASHRAE 62.1 and 62.2). Rate procedure inputs (zone outdoor airflow, occupant density, area component), system ventilation efficiency, and 62.2 mechanical-ventilation rates for dwellings.
Hydronics and boilers. Pump sizing, system head curves, expansion-tank sizing, low-water cutoffs, and ASME boiler-room ventilation.
IECC envelope and equipment efficiency. Climate-zone tables, ductwork insulation R-values, equipment minimum efficiencies, commissioning, and economizer requirements.
Indoor air quality and humidity. Dehumidification load, makeup-air sizing for kitchen and lab exhaust, and IAQ contaminant control. Florida and Gulf Coast exams emphasize this category.

HVAC / Mechanical contractor exam study plan

Build a Category I-IV vent chart you can sketch from memory. Examiners love venting category questions and they are easy points if you know the rules cold.
Memorize the 7 ASHRAE 62.1 building-type ventilation rates you are most likely to design. Look up the rest in the table.
Practice one full Manual J residential calc by hand before you take any timed exam - if you cannot do it on paper, you will not recognize the wrong answers under time pressure.
Take a topic-focused drill on combustion air and another on refrigerant handling. These two areas catch more first-time test-takers than any other.
Two weeks before test day, take a full-length timed exam and review every miss with a code reference. Re-take in the last week only if you scored under 75%.

See our 30-day crunch plan for a compressed version, or our full exam prep guide for the extended one.

Pick your state for HVAC / mechanical contractor licensing details

Each state has its own HVAC / mechanical contractor license tiers, fees, experience requirements, and reciprocity agreements. Pick your state below for the exact licensing board, application checklist, accepted code editions, and state-specific topics that go beyond the national code references covered on this page.

New England

Cold winters, nor'easters, and historic preservation challenges define construction in these states.

Mid-Atlantic

Dense urban development, historic buildings, and freeze-thaw cycles present unique challenges.

Southeast

Hurricane exposure, humidity, and termite risks dominate construction concerns. Several states accept NASCLA.

Gulf Coast

Hurricane-resistant construction, flood zones, and strict wind codes are essential knowledge.

Midwest & Great Lakes

Extreme temperature swings, heavy snow loads, and tornado risks influence building practices.

Great Plains

Severe weather, tornadoes, and wide temperature ranges define construction in these states.

Mountain West

High altitude, heavy snow, wildfires, and seismic activity create unique building challenges.

Southwest

Extreme heat, flash floods, expansive soils, and desert construction techniques are emphasized.

West Coast

Seismic design, wildfires, and some of the nation's strictest building codes apply.

Alaska & Hawaii

Extreme climates - arctic cold or tropical conditions - require specialized construction knowledge.

All 51 state licensing guides →

HVAC / Mechanical practice questions and timed exams

Our timed practice exams use the same style, difficulty curve, and code references you will see on test day. Each attempt gives you an instant score, detailed rationales with code-section citations, and a weak-topic map so you know exactly where to focus next.

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HVAC / Mechanical contractor exam FAQ

Do I need an EPA Section 608 card to take the HVAC contractor exam?

No - EPA 608 is a separate federal certification for refrigerant handling. You can take the state HVAC contractor exam without it, but you cannot purchase or recover refrigerant in the field until you hold the appropriate 608 certification (Type I, II, III, or Universal).

How many questions are on the HVAC / mechanical contractor exam?

Most state HVAC exams run 70 to 100 multiple-choice questions over 3.5 to 4 hours, with a 70 percent passing score. Some states (Florida, Louisiana) split the exam into mechanical and business modules taken on different days.

Is the HVAC contractor exam open-book?

Yes. The IMC, IFGC, IECC, ASHRAE 62.1 / 62.2, and OSHA 1926 are typically allowed - all tabbed and highlighted only.

What is the difference between an HVAC and a mechanical contractor license?

In most states the two terms are interchangeable. A few states (notably Texas) split them: a Mechanical license covers air-conditioning, refrigeration, hydronics, and boilers; an HVAC license is a narrower scope without high-tonnage commercial refrigeration. Check the classification list in your state.

How much field experience do I need to qualify?

Most states require 4 to 6 years of documented HVAC work experience, with at least 2 years at the journeyman or supervisor level. Some states accept a vocational degree in HVAC for up to half the experience requirement.