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Louisiana HVAC, Refrigeration & Duct Work Licensing Exam — Practice Test Guide

What This Practice Exam Covers

The Louisiana Heat, Air Conditioning, Ventilation, Duct Work, and Refrigeration licensing exam is 50 questions answered in 130 minutes. You need a 70% (35 correct) to pass. Questions span 8 technical topic areas, weighted by item count, and draw from electrical theory, refrigerant regulations, load calculations, piping, combustion, venting, and duct standards.

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 — it costs nothing and is a fast way to get a feel for question style, difficulty, and pacing before you commit to serious study.
• Full practice exam (paid): 50 questions, 130-minute timer, drawn from a pool of 348+ questions. Every attempt produces a different set, so repeated attempts genuinely test different material. This mirrors the real exam experience and gives you the topic-by-topic score breakdown you need to study efficiently.

Start with the free exam to calibrate, then use the full exam for targeted preparation.

What You'll Be Tested On

Electrical Knowledge, Motors, and Controls — 7 items

This is one of the heaviest sections. Expect calculation questions requiring Ohm's Law (V = IR) and Watt's Law (P = IE), plus series and parallel circuit analysis. Motor questions focus on single-phase types — split-phase, CSIR, CSCR, PSC, and shaded-pole — and you must know how each starts and what differentiates it. Three-phase motor wiring (wye vs. delta), connection methods, and full-load current values also appear. Capacitor questions test both function and field testing: you need to know how a start capacitor differs from a run capacitor and how to verify each with a meter. Control components — thermostats, pressure controls, current relays, potential relays, PTC relays, and solid-state relays — appear in both identification and troubleshooting contexts. Source material for this section includes Modern Refrigeration and Air Conditioning Chapters 15–17 and the Ohm's Law reference.

Piping — Refrigeration, Hydronic, Steam, Process — 7 items

Questions cover ACR copper tubing types (Type K, L, and M), support spacing, and routing restrictions. You must know the difference between soldering, brazing, flaring, and swaged connections, and when each is appropriate. Hydronic piping questions address IMC standards for materials, fittings, and joint types — including series loop, one-pipe, two-pipe, and radiant configurations. Boiler and pressure vessel questions test safety relief valve requirements and clearances. Refrigerant system classification (high-probability vs. low-probability) and allowable refrigerant quantities also fall here. Citations include IMC Chapter 12, Sections 1206.8, 1208.1, 1209.1, and 1209.5.1, as well as the Copper Tube Dimensions sections covering Types K, L, and M.

Heating and Cooling Principles, Theory, and Equipment — 8 items

The largest topic. You must understand every stage of the vapor-compression refrigeration cycle — evaporation, condensation, compression, and metering — and be able to diagnose abnormal conditions from pressure and temperature readings. Heat transfer questions distinguish conduction, convection, and radiation, and require you to separate sensible from latent heat loads. Compressor type questions (reciprocating, rotary, scroll, screw, centrifugal) test mechanical differences and application ranges. Metering devices — capillary tubes, TXV, AXV, and EEV — are tested on control method (fixed vs. modulating) and response to system conditions. Gas-fired heating questions cover combustion principles, burner types, ignition systems, and AFUE ratings. Primary references are Modern Refrigeration and Air Conditioning Chapters 8 and related sections.

Refrigerants and Refrigeration — 8 items

Tied for the largest topic. Refrigerant classification (CFC, HCFC, HFC, HFO, HC, and blends) appears alongside ODP and GWP values and the regulatory framework — Montreal Protocol and Clean Air Act Section 608. EPA certification types (Type I, II, III, Universal) and their scope are directly tested. You must know the refrigerant numbering system, cylinder color codes, and how to read pressure-temperature charts. Recovery procedures — passive vs. active, and required evacuation levels by system pressure classification — are high-frequency questions. Superheat and subcooling calculations are required for checking refrigerant charge.

Fuel and LP Gas — 5 items

Allowable piping materials (steel, copper, CSST, polyethylene) and their installation requirements under the IFGC are tested, along with pipe sizing using capacity tables for both natural gas and LP. LP gas properties, storage requirements, and two-stage pressure regulation are covered. Combustion air calculations for gas-fired appliances and ignition system types (standing pilot, intermittent pilot, direct-spark, hot-surface) round out this section. Key citations include International Fuel Gas Code 2021, pages 3-3 through 3-7, 4-39 through 4-48, and Appendix D.

Combustion Air, Chimneys, Flues and Vents — 5 items

You must match appliance categories (Category I–IV) to the correct venting system type (Type B, BW, L). Termination height and clearance requirements, vent connector slope, material, and sizing using code tables for single and multiple appliances are all tested. Draft hood and mechanical draft system questions also appear. Relevant citations include International Mechanical Code Sections 801.6, 801.7, 801.12, 801.16.1, 801.18.1, 802.5, 802.6, 803.10.5, 804.3.4, 805.2, and 805.4, and IMC Table 803.9(1).

Ducts, Ventilation and Exhaust — 5 items

Rectangular duct wall gauge, reinforcement schedules, and pressure classification appear alongside round, oval, and flexible duct construction standards. Duct sealing and leakage class requirements, airtightness testing, and hanger/support systems are tested. Ventilation rate questions require knowledge of outdoor air requirements by occupancy. Exhaust system questions address discharge location, independent exhaust systems, and hazardous exhaust handling. Citations include IMC Chapter 10, Sections 1006.4 and 1006.6, and IMC Chapter 11, Sections 1108.3.1, 1108.3.3, and 1109.2.7.

Load Calculations — 5 items

Design condition questions use heating and cooling temperature differences (HTD, CTD) and grains difference for latent loads. Fenestration questions require applying HTM values, U-values, and shading corrections. Opaque panel loads use CLTD methods. Infiltration loads are estimated via the ACH method or component leakage approach. Duct load questions address heat loss factors, sensible/latent gain factors, and the effect of duct leakage and insulation. IMC Chapter 13, Sections 13.1 and 13.2.1, support this section.

Worked Sample Questions

Sample 1 — Heating and Cooling Principles

Question: Low suction pressure and high superheat in cooling mode indicates:

• A. Overcharge
• B. Undersized metering device
• C. Low indoor airflow
• D. Low refrigerant charge

Correct Answer: D — Low refrigerant charge

When refrigerant charge is low, there is less liquid entering the evaporator. The evaporator becomes "starved," meaning the small amount of refrigerant that does enter boils off very quickly and continues absorbing heat as a superheated vapor for the remainder of the coil. This produces two simultaneous readings: suction pressure drops below normal (less refrigerant mass in the low side), and superheat rises above normal (vapor is heated far past saturation). An overcharge would produce the opposite — high suction pressure and low superheat. Low airflow reduces the heat available to the evaporator, which typically lowers suction pressure but also lowers superheat, not raises it.

Sample 2 — Refrigerants and Refrigeration

Question: What is the required evacuation level for recovery of R-410A in high-pressure systems?

• A. 0 psig
• B. 10" Hg vacuum
• C. 15" Hg vacuum
• D. 20" Hg vacuum

Correct Answer: A — 0 psig

Under EPA Section 608 regulations, high-pressure appliances (which include R-410A systems) with a charge under 200 pounds must be evacuated to 0 psig before the refrigerant is considered recovered. This is a lower vacuum requirement than what applies to low-pressure appliances such as centrifugal chillers using R-11 or R-113, which require a deep vacuum because their operating pressures are below atmospheric. Knowing which refrigerant falls into which pressure classification — and the corresponding required recovery level — is a direct exam question type.

Sample 3 — Electrical Knowledge, Motors, and Controls

Question: Compressor FLA is 22A and LRA is 5.5 × FLA. What is LRA?

• A. 110A
• B. 120A
• C. 125A
• D. 130A

Correct Answer: B — 120A

Locked Rotor Amperage (LRA) is the current a motor draws the instant it starts, before the rotor begins turning. Multiply FLA by the given LRA multiplier: 22 × 5.5 = 121A. Among the answer options, 120A is the closest value. On the real exam, multi-step electrical calculations like this one are common — work the arithmetic carefully and select the nearest available option rather than expecting an exact match.

How to Read Your Score

The passing threshold is 70%, meaning 35 out of 50 correct on the real exam. On your first practice attempt, treat your score as a diagnostic, not a verdict. Most candidates find their first score reflects gaps in specific topic areas rather than a general lack of knowledge.

A score below 60% on a first attempt is normal and means you have clear areas to target — use the topic-by-topic breakdown to identify which of the eight areas are pulling you down. A score in the 60–69% range means you are close but not consistently solid. Scoring near 70% on practice is not the same as being ready to pass the real exam: the real test draws from a broader question pool, and exam-day pressure affects performance. Aim for consistent 80%+ scores across multiple full practice attempts before scheduling.

Because the full exam draws from 348+ questions, each retake surfaces new material. Use that variation deliberately: if you score 90% on refrigerants but 55% on load calculations, shift your study hours accordingly rather than reviewing what you already know.

Where Candidates Lose Points

Unit errors in electrical calculations. Ohm's Law and Watt's Law questions mix volts, amps, ohms, watts, and kilowatts. Confusing kW with W — or forgetting to convert — produces wrong answers that look almost right.

Wrong evacuation level for the wrong refrigerant. The EPA 608 recovery requirements differ by system pressure classification. Candidates who memorize one number and apply it universally lose these points. Know which refrigerants are high-pressure vs. low-pressure.

Misidentifying single-phase motor types. The exam distinguishes split-phase, CSIR, CSCR, PSC, and shaded-pole motors by starting method and capacitor configuration. Confusing CSIR (start capacitor only) with CSCR (start and run capacitors) is a common error. Reference Modern Refrigeration and Air Conditioning, Chapter 15, Section 15.2.1 for each motor type.

Skipping steps in load calculations. HTM, CLTD, and infiltration questions require multiple inputs applied in sequence. Candidates who jump to an answer after one step consistently choose the trap option.

Venting category mismatches. Applying Type B vent to a Category III or IV appliance — or confusing vent connector slope direction — costs points in the Combustion Air, Chimneys, Flues and Vents section. The IMC table citations are specific; know which table governs single vs. multiple appliance venting.

Running out of time on calculation-heavy sections. Electrical and load calculation questions take longer than definition questions. Budget time accordingly across the 130 minutes.

Exam Quick Facts