Louisiana Heat, Air Conditioning, Ventilation, Duct Work and Refrigeration

Louisiana HVAC Contractor Exam: What You Need to Know to Pass

Getting your Louisiana HVAC contractor license opens doors to more jobs, higher bids, and the ability to run your own shop. But first, you have to pass the Louisiana Heat, Air Conditioning, Ventilation, Duct Work and Refrigeration exam — and it covers a lot of ground. This article breaks down exactly what's on the test, what books to bring, and how to study smart so you're not guessing on exam day. You can also try our free practice exam right now to see where you stand.

Louisiana HVAC and Refrigeration Exam Overview

The Louisiana heat air conditioning ventilation refrigeration exam is administered by PSI on behalf of the state licensing website. Here's the basic structure:

• Questions: 50 scored questions
• Time limit: 130 minutes
• Passing score: 70% — that's 35 correct answers out of 50
• Format: Open book (approved references only)

At roughly two and a half minutes per question, you have enough time to look things up — if your books are tabbed and you know where to go. This is not a memorization marathon. It rewards preparation and organization. Check the official exam bulletin for the most current details, and register through the exam registration page.

Topics Covered on the Louisiana HVAC Contractor Exam

The LSLBC HVAC license test covers eight topic areas. Here they are ranked by how many questions appear on the real exam — study accordingly.

Heating and Cooling Principles, Theory, and Equipment (8 questions)
The refrigeration cycle, compressor types, metering devices, heat exchangers, and defrost methods. This is the core of the trade.

Refrigerants and Refrigeration (8 questions)
Refrigerant classification, ODP and GWP, EPA Section 608 rules, cylinder color codes, and recovery procedures. Know this cold — you'll see it without opening a book.

Electrical Knowledge, Motors, and Controls (7 questions)
Ohm's Law, Watt's Law, series and parallel circuits, single-phase and three-phase motors, capacitors, and fuse sizing. Ugly's Electrical References is your friend here.

Piping — Refrigeration, Hydronic, Steam, Process (7 questions)
ACR tubing, brazing and flaring techniques, hydronic fittings, boiler connections, and safety valves.

Fuel and LP Gas (5 questions)
Gas pipe materials and sizing, LP gas properties, combustion air requirements, and furnace ignition systems. Straight code lookups from the IFGC.

Combustion Air, Chimneys, Flues and Vents (5 questions)
Vent categories, termination heights, vent connector sizing, and mechanical draft systems.

Ducts, Ventilation and Exhaust (5 questions)
Duct construction standards, sealing requirements, hangers, and ventilation rates by occupancy.

Load Calculations (5 questions)
Design temperatures, heat transfer through walls and windows, infiltration, and duct system loads using Manual J methods.

Sample Questions from the Louisiana HVAC and Refrigeration Exam

Here are five sample questions that reflect the style and difficulty of what you'll see. Try them yourself — answers are not listed here. Take our free practice exam to check your knowledge.

Question 1 — Electrical Knowledge, Motors, and Controls (Easy)

You are troubleshooting a commercial air handler that has three resistive heating elements wired in series with values of 30 ohms, 45 ohms, and 25 ohms. What is the total resistance of this circuit?

• A) 75 ohms
• B) 33.3 ohms
• C) 25 ohms
• D) 100 ohms

This tests your ability to apply basic Ohm's Law to a series circuit — something you should be able to work out with a calculator and no reference book.

Question 2 — Electrical Knowledge, Motors, and Controls (Medium)

For a three-phase AC polyphase squirrel-cage motor (other than Design B energy-efficient), what is the maximum rating of a dual-element time-delay fuse expressed as a percent of full-load current?

• A) 150%
• B) 300%
• C) 175%
• D) 250%

This is a code-table question. Know where to find motor protection sizing in your references.

Question 3 — Load Calculations (Easy)

A material's thermal conductivity (K-value) measures the amount of heat that will pass through one square foot of the material at what thickness, in one hour, when there is a 1°F temperature difference between the two sides?

• A) Any measured thickness
• B) One-half inch thick
• C) One foot thick
• D) One inch thick

A definitions question from Manual J load calculation fundamentals.

Question 4 — Load Calculations (Medium)

According to the mixed-air diagram, what is the total mixed airflow leaving the plenum, and does it agree with the sum of the entering streams?

• A) 3,000 CFM, matching only the return-air stream
• B) 4,000 CFM, which equals 3,000 + 1,000 CFM entering
• C) 5,000 CFM, more than the sum of the entering streams
• D) 2,000 CFM, the difference of the two streams

Tests your ability to read an airflow diagram and apply mass-balance principles.

Question 5 — Heating and Cooling Principles, Theory, and Equipment (Medium)

Demand defrost typically initiates based on:

• A) Outdoor temp only
• B) Time clock
• C) Coil temp and compressor run time
• D) Thermostat demand

Covers defrost control strategies — one of the equipment operation concepts you need to know from Modern Refrigeration.

What Types of Questions to Expect

Here's what the Louisiana mechanical contractor practice exam questions actually test, by topic.

Electrical Knowledge, Motors, and Controls
Expect series/parallel circuit math, Ohm's and Watt's Law calculations, motor starting method identification (split-phase, PSC, CSIR, CSCR, shaded-pole), three-phase motor connections and full-load current values, and capacitor testing and replacement.

Piping — Refrigeration, Hydronic, Steam, Process
Questions on ACR tubing types and supports, brazing and flaring procedures, hydronic fittings and joint types per IMC Chapter 12, system configurations (series loop, two-pipe, radiant), and boiler safety valve requirements.

Heating and Cooling Principles, Theory, and Equipment
The refrigeration cycle step by step, heat transfer modes, compressor type identification, metering device operation (TXV, EEV, capillary tube), and heat exchanger and defrost system questions.

Refrigerants and Refrigeration
Refrigerant numbering, CFC/HCFC/HFC/HFO classification, ODP and GWP values, EPA Section 608 certification types, cylinder color codes, pressure-temperature chart reading, and active vs. passive recovery methods.

Fuel and LP Gas
Gas pipe material selection, pipe sizing table lookups, LP gas storage and two-stage regulation, combustion air calculations, and ignition system types (hot-surface, direct-spark, intermittent pilot).

Combustion Air, Chimneys, Flues and Vents
Appliance venting categories (I through IV), vent termination clearances, vent connector slope and material requirements, single and multi-appliance vent sizing tables, and draft control devices.

Ducts, Ventilation and Exhaust
Rectangular duct gauge and reinforcement schedules, flexible and round duct standards, sealing class requirements, duct hanger spacing, and outdoor air requirements by occupancy type.

Load Calculations
Design temperature and HTD/CTD values, fenestration load calculations using HTM values and U-factors, opaque wall and ceiling loads with CLTD, ACH-based infiltration, and duct loss/gain factors.

Total across all topics: 557 practice questions.

Required Study Materials

This exam is open book — but only specific approved references are allowed in the testing room. Buy them, tab them, and know them before exam day.

• Modern Refrigeration and Air Conditioning — Your primary reference for the refrigeration cycle, compressors, metering devices, refrigerants, and recovery procedures. The two heaviest topics on the exam (Heating and Cooling Principles plus Refrigerants) both come from here.

• International Mechanical Code 2021 — Covers duct construction, ventilation rates, hydronic piping, and venting. Tab it by chapter.

• International Fuel Gas Code 2021 — Go-to for gas pipe sizing tables, combustion air, and venting requirements. The pipe sizing section alone covers multiple exam questions.

• HVAC Duct Construction Standards, Metal and Flexible (3rd) — Required for duct gauge, reinforcement schedules, and sealing class questions.

• Manual J - Residential Load Calculation (8th) — Required for the five load calculation questions. Work through a full example before the exam.

• Ugly's Electrical References 2020 — Compact and fast to use. Fuse sizing tables, motor data, and circuit formulas in one small book.

You are responsible for bringing your own copies to the testing center.

Study Tips for the Louisiana HVAC and Refrigeration Exam

Tab your books before you walk in. The open-book format only helps if you can find answers fast. Tab the IMC by chapter, and mark the pipe sizing tables, combustion air section, and venting section in the IFGC.

Focus first on the heaviest topics. Heating and Cooling Principles (8 questions) and Refrigerants and Refrigeration (8 questions) are 32% of your score combined. Get those right and you're halfway to passing before you touch anything else.

Know the refrigeration cycle and refrigerant basics without the book. Questions on the compression cycle, refrigerant classifications, and EPA Section 608 rules move faster when you're not flipping pages.

Work two or three full Manual J examples. Load Calculations (5 questions) has specific steps. Running through a heat loss and heat gain problem once or twice makes the exam questions much more familiar.

Don't skip the motor math. Series and parallel resistance, Ohm's Law, and fuse sizing percentages for motors are straightforward if you practice. Keep Ugly's tabbed at the motor tables.

Manage your time. 130 minutes for 50 questions is about 2.5 minutes each. If a code-lookup question is taking too long, mark it and come back.

Ready to Start Preparing?

The Louisiana HVAC contractor exam is manageable — 50 questions, open book, and a 70% passing score. That's 35 correct answers. Get your books, tab them properly, and put in the work on the refrigeration cycle, refrigerant rules, and motor calculations.

Start with our free practice exam to see how you score right now — no account needed, no payment required. When you're ready to go deeper, the full practice exam mirrors the real test with the same topic breakdown, time limit, and a large question pool so you're never seeing the same exam twice. Good luck.