In Louisiana, heating and air-conditioning contractors are licensed by the State Licensing Board for Contractors under subclassification 6.1 of Mechanical: Heat, Air Conditioning, Ventilation, Duct Work and Refrigeration. It is a classification on a commercial license, it applies once a job reaches $10,000, residential jobs included, and it has its own trade exam at PSI, shorter than the full Mechanical Work exam and open book. This guide covers when you need it, how it differs from Mechanical, and what PSI's content outline says about the exam.
The Contractors Licensing Law counts air conditioning, refrigeration, heating and ventilation as mechanical work, for residential, commercial and industrial applications alike, and requires a license once the project value, labor and materials together, is $10,000 or more (La. R.S. 37:2150.1(13)). The Board's license-types page lists mechanical projects over $10,000 under the commercial license, and its classification list describes subclassification 6.1 as the installation, maintenance or repair of air conditioning, ventilation, refrigeration, coolers, freezers and ice rinks, marked “Trade Exam”. So a residential change-out at that value is licensed work, even though the license itself is a commercial one.
6.1 is a subclassification of Mechanical, major classification 6. A Mechanical licensee may do all 6.1 work, because a major classification covers its subclassifications (LAC 46:XXIX §301), but not the other way round: Mechanical also covers plumbing, gas and process piping, boilers and pressure vessels, and other systems that 6.1's published scope does not name. The exams differ to match. The 6.1 exam is 50 questions in 130 minutes; Mechanical Work is 100 questions in 240 minutes, and more than a third of it is plumbing code. If you only do heating, cooling, ventilation, ductwork and refrigeration, 6.1 is the narrower path; if you bid wider mechanical work, look at Mechanical.
PSI's Louisiana outline sets the format: 50 questions, 130 minutes, and a minimum passing score of 35 correct, which is 70 percent. The questions fall into eight content areas: Heating and Cooling Principles, Theory and Equipment 8; Refrigerants and Refrigeration 8; Electrical Knowledge, Motors and Controls 7; Piping (refrigeration, hydronic, steam and process) 7; Fuel and LP Gas 5; Combustion Air, Chimneys, Flues and Vents 5; Ducts, Ventilation and Exhaust 5; and Load Calculations 5. PSI's fee is $140, and a retake costs another $140.
It is open book. The references allowed in the room are the 2021 International Mechanical Code and 2021 International Fuel Gas Code; ACCA Manual J for residential load calculations (2016 reprint); Modern Refrigeration and Air Conditioning (20th or 21st edition); SMACNA's HVAC Duct Construction Standards, Metal and Flexible (2005); and Ugly's Electrical References (2014, 2017 or 2020 edition). Note the code editions: this exam uses the 2021 IMC and IFGC, while the Mechanical Work exam uses the 2018 editions, and for code questions each exam is based only on the edition it lists. PSI's bulletin also allows any brand of duct calculator in the room, such as those from ACCA, Trane, Bell & Gossett or a Datalyzer slide chart.
You schedule after the Board approves your qualifying party and PSI emails the eligibility notice, which lasts one year. PSI's March 2026 bulletin sets the room rules: bring your own references, highlighted, annotated and permanently tabbed in advance but not written in during the exam; no loose papers, so printed material must be bound; and only a silent, non-programmable calculator without an alphabet keyboard, no scientific calculators. Cancel at least two days ahead or lose the fee. If you fail, the Board's rule makes you wait 30 days before retaking (LAC 46:XXIX §111). The exam comes on top of the Business and Law requirement, which every applicant's qualifying party completes online in the LSLBC portal.
The LSLBC license is for the contracting business. Handling refrigerant is regulated separately by the federal government: anyone who could reasonably be expected to open the refrigerant circuit of an appliance during maintenance, service, repair or disposal must pass an EPA-approved Section 608 technician certification exam, Type I for small appliances, Type II for medium-, high- and very-high-pressure appliances, Type III for low-pressure appliances (40 CFR 82.161). You and your technicians need that regardless of the state license, and our free EPA 608 practice covers Core and all three types.
With 130 minutes for 50 questions you have about two and a half minutes per question. Tab the IMC chapters on equipment, ducts, exhaust and refrigeration and the IFGC chapters on pipe sizing, combustion air and venting, and practice using your duct calculator and Manual J under time. The electrical area is 7 questions, and the reference list includes Ugly's Electrical References, not the NEC, so get comfortable with Ugly's motor and wiring tables. LICENA's Louisiana HVAC and Refrigeration bank follows the eight outline areas, with a written explanation on every answer.
Practice the Louisiana HVAC exam LICENA's Louisiana HVAC and Refrigeration (6.1) bank follows PSI's eight content areas, with a written explanation on every answer in English, Spanish and Russian. The sample is free, no sign-up.
Try the free practice test → Free EPA 608 practice test