Texas Environmental Air Class B Contractor Book Package

Prepare for the Texas Environmental Air Class B Contractor examination with a comprehensive collection of Texas licensing references, current mechanical and fuel-gas codes, HVAC technical books, duct-sizing resources, load-calculation manuals, and equipment-selection materials. This book package is designed for contractors preparing for the Texas Environmental Air Class B examination administered for the Texas Department of Licensing and Regulation.

The Texas Environmental Air Conditioning endorsement covers the treatment of air to control temperature, humidity, cleanliness, ventilation, and circulation for human comfort. A Class B license allows a contractor to perform work within the Environmental Air endorsement on individual systems, products, or equipment of up to 25 tons of cooling capacity or 1.5 million Btu per hour of heating output.

The Environmental Air Class B examination combines HVAC theory, installation requirements, system design, air distribution, refrigeration, controls, combustion air, piping, safety, service, testing, ventilation, venting, and Texas licensing requirements. Because the examination is open book, candidates also need to know how to move efficiently between mechanical codes, fuel-gas requirements, Texas laws and rules, technical HVAC references, and residential design manuals.

Beginning September 1, 2026, Texas updated the adopted mechanical and fuel-gas codes to the 2024 editions. This package includes the 2024 Uniform Mechanical Code, 2024 International Mechanical Code, and 2024 International Fuel Gas Code, supporting preparation with the current code editions used for Texas Air Conditioning and Refrigeration requirements.

The package also includes resources for residential load calculations, duct-system design, and equipment selection. These references help candidates prepare for questions involving airflow, system capacity, duct sizing, sensible and latent loads, equipment selection, and other practical HVAC design concepts.

Exam Details

The Texas Environmental Air Class B examination is one of the contractor examinations offered for the Texas Air Conditioning and Refrigeration Contractors program. The examination is administered through PSI for the Texas Department of Licensing and Regulation.

• Exam: Texas Environmental Air Class B
• Licensing Agency: Texas Department of Licensing and Regulation
• Testing Provider: PSI
• Scored Questions: 100
• Time for Scored Questions: 170 minutes
• Non-Scored Questions: 5
• Additional Time for Non-Scored Questions: 10 minutes
• Passing Score: 70%
• Exam Type: Open book
• License Class: Class B
• Endorsement: Environmental Air Conditioning

The current Environmental Air Class B examination covers a broad group of HVAC topics. Major technical areas include:

• Air Distribution: 15 questions
• Basic Refrigeration Components: 5 questions
• Combustion Air: 5 questions
• Controls: 5 questions
• Equipment Requirements and Design: 12 questions
• HVACR Systems: 9 questions
• Piping: 5 questions
• Refrigeration Principles: 5 questions
• Safety: 5 questions
• Service: 10 questions
• Testing: 10 questions

Air Distribution is the largest individual technical category, followed by Equipment Requirements and Design, Service, Testing, and HVACR Systems. Candidates should build a balanced study plan because the examination evaluates both system knowledge and practical contractor-level application.

Open Book Test

The Texas Environmental Air Class B Contractor examination is an open book test.

Candidates may bring approved references identified for the examination. Open-book testing makes advance organization important because candidates must locate information efficiently while working within the testing time limit.

Approved reference books may generally be highlighted, underlined, and contain notes made before the examination. Permanent index tabs may be used when they meet testing-center requirements. Temporary tabs, removable notes, and loose additional papers are not permitted.

Candidates are not permitted to add notes, highlighting, underlining, or indexing to their books during the examination session. Preparing and organizing approved references before test day can therefore be an important part of exam preparation.

The examination includes both reference-based and knowledge-based questions. Candidates should not expect every technical question to be solved by searching a code book. Refrigeration principles, troubleshooting, airflow, controls, equipment operation, testing procedures, and system design also require practical trade knowledge.

For current Texas code preparation, candidates should become familiar with the 2024 International Mechanical Code, 2024 International Fuel Gas Code, and 2024 Uniform Mechanical Code.

Licensing Steps

Texas Air Conditioning and Refrigeration Contractor licensing is administered through TDLR. The license class and endorsement selected by the applicant determine both the permitted work and the contractor examination.

1. Meet the age requirement. Applicants must be at least 18 years old.
2. Meet the applicable experience requirement. The standard experience pathway requires at least 48 months of practical air-conditioning and refrigeration experience under qualifying supervision during the preceding 72 months.
3. Use an alternate qualifying pathway when applicable. Texas provides additional experience pathways for applicants who meet specific technician-certification or other qualifying experience requirements.
4. Select Class B Environmental Air Conditioning. The class establishes equipment-capacity limits, while the Environmental Air endorsement establishes the type of HVAC work authorized.
5. Submit the contractor application to TDLR. TDLR reviews applicant eligibility before authorizing examination registration.
6. Receive examination eligibility. Approved applicants receive instructions for scheduling the required examination through PSI.
7. Prepare with the current approved references. Study Texas law, contractor rules, HVAC codes, technical references, and design manuals applicable to Environmental Air Class B.
8. Take the Environmental Air Class B examination. Complete the scored and non-scored examination portions within the allotted testing time.
9. Achieve the required passing score. The current passing score is 70%.
10. Complete remaining licensing requirements. Follow TDLR procedures, including applicable insurance and licensing documentation requirements, before the contractor license is issued.

State Requirements

A Texas Class B Environmental Air Conditioning license authorizes contracting work involving environmental air-conditioning systems within the Class B capacity limits.

The Class B license permits work on individual cooling systems with a capacity of 25 tons or less and individual heating systems with an output of 1.5 million Btu per hour or less.

Environmental Air Conditioning refers to treating air for human comfort by controlling temperature, humidity, cleanliness, ventilation, and circulation. This includes common residential and qualifying commercial heating and air-conditioning applications within the Class B capacity limits.

A building or complex may contain multiple HVAC units whose combined capacity exceeds the Class B limits, provided each complete individual unit remains within the applicable Class B limitation.

Texas requires applicants to satisfy practical-experience requirements before qualifying for a contractor license. The standard pathway requires at least 48 months of practical experience during the preceding 72 months under qualifying supervision.

The contractor examination is only one part of the licensing process. Candidates must also complete the applicable TDLR application, experience documentation, insurance, and licensing requirements.

Reference Books

• Texas Air Conditioning and Refrigeration Contractors License Law, Texas Occupations Code, Chapter 1302
  Covers the statutory framework for Texas air-conditioning and refrigeration contractor licensing, including license classes, endorsements, contractor responsibilities, enforcement, and regulatory authority.
• Texas Air Conditioning and Refrigeration Contractors License Rules, Texas Administrative Code, Chapter 75
  Contains the administrative rules governing the Texas Air Conditioning and Refrigeration Contractors program and supports preparation for state law and licensing questions.
• OSHA 29 CFR 1904
  Covers federal requirements related to recording and reporting occupational injuries and illnesses and supports contractor safety and compliance study.
• Uniform Mechanical Code, 2024
  Covers mechanical-system installation, ventilation, combustion air, duct systems, HVAC equipment, refrigeration, exhaust, and related mechanical requirements.
• International Mechanical Code, 2024
  Provides mechanical-code requirements covering heating, cooling, ventilation, duct systems, equipment installation, exhaust, refrigeration systems, and related HVAC work.
• International Fuel Gas Code, 2024
  Covers gas piping, combustion air, fuel-burning appliance installation, venting, gas-system testing, and fuel-gas safety requirements.
• Modern Refrigeration and Air Conditioning, 22nd Edition
  A comprehensive technical HVAC reference covering refrigeration principles, components, electrical controls, heating and cooling systems, service procedures, troubleshooting, and equipment operation.
• Ductulator
  A practical duct-sizing resource used to evaluate airflow, duct dimensions, velocity, friction rate, and other air-distribution relationships.
• Manual D, 2016, 3rd Edition
  A residential duct-system design reference that supports study of airflow, static pressure, friction rate, duct sizing, fittings, and distribution-system design.
• Manual J - Residential Load Calcs, Reprinted 2016, Eighth Full Edition
  A residential heating and cooling load-calculation reference used to evaluate building heat gain and heat loss for HVAC system design.
• Manual S - Residential Equipment Selection
  A residential equipment-selection reference used to match heating and cooling equipment performance to calculated building loads.

Exam Room Approved Books

• Texas Air Conditioning and Refrigeration Contractors License Law, Texas Occupations Code, Chapter 1302
  An approved Texas law reference for Air Conditioning and Refrigeration contractor examination preparation.
• Texas Air Conditioning and Refrigeration Contractors License Rules, Texas Administrative Code, Chapter 75
  An approved rules reference covering Texas contractor licensing and regulatory requirements.
• OSHA 29 CFR 1904
  The OSHA recordkeeping and reporting reference included in the contractor examination reference materials.
• Uniform Mechanical Code, 2024
  The 2024 edition is part of the updated Texas mechanical-code framework effective September 1, 2026.
• International Mechanical Code, 2024
  The 2024 edition is part of the current Texas Air Conditioning and Refrigeration code framework.
• International Fuel Gas Code, 2024
  The 2024 edition provides current fuel-gas provisions used for Texas HVAC contractor preparation.
• Modern Refrigeration and Air Conditioning, 22nd Edition
  A technical examination reference covering HVAC fundamentals, refrigeration, service, controls, and system operation.
• ADI Duct Size Calculator
  A duct-sizing calculator used for air-distribution calculations and airflow-related exam preparation.
• Manual D - Residential Duct Systems
  The approved examination reference list identifies the applicable Manual D edition for Environmental Air Class A and Class B examinations.
• Manual J - Residential Load Calculation
  Used for residential heating and cooling load calculations and system-design questions.
• Manual S - Residential Equipment Selection
  Used for residential HVAC equipment-selection procedures and matching equipment performance to calculated loads.

Candidates should use the exact editions identified in the current examination bulletin when selecting books for the exam room. The books included in this package should be used according to their intended study and testing purpose.

Test Information and Study Materials

Air Distribution: Air Distribution is the largest current technical category with approximately 15 questions. Study airflow, duct sizing, friction loss, velocity, static pressure, registers, grilles, return-air systems, supply systems, and practical duct design.

Equipment Requirements and Design: Approximately 12 questions involve equipment requirements and design. Review equipment capacity, load calculations, installation requirements, clearances, system selection, and proper application of residential design procedures.

Service: Approximately 10 questions address service-related knowledge. Candidates should understand common HVAC faults, system operation, refrigerant conditions, electrical troubleshooting, airflow problems, and service procedures.

Testing: Approximately 10 questions involve system testing. Review electrical measurements, refrigerant pressures and temperatures, superheat, subcooling, airflow measurement, combustion testing, and gas-system testing principles.

HVACR Systems: Approximately nine questions cover complete system operation and equipment interaction. Study heating systems, cooling systems, heat pumps, furnaces, air handlers, refrigeration circuits, and system components.

Basic Refrigeration Components: Understand compressors, evaporators, condensers, metering devices, filter-driers, accumulators, receivers, and other common refrigeration components.

Refrigeration Principles: Review pressure-temperature relationships, heat transfer, sensible heat, latent heat, refrigerant states, superheat, subcooling, and the basic refrigeration cycle.

Controls: Study thermostats, relays, contactors, pressure controls, safety controls, transformers, control voltage, and equipment sequencing.

Combustion Air: Review requirements for supplying combustion, ventilation, and dilution air to fuel-burning appliances and learn how enclosure conditions affect combustion-air requirements.

Fuel Gas and Venting: Use the International Fuel Gas Code and applicable mechanical-code provisions to review appliance venting, vent connectors, gas piping, shutoff valves, regulators, pressure testing, combustion air, and installation safety.

Manual J: Practice residential heating and cooling load calculations, including heat gain and heat loss considerations that influence system sizing.

Manual D: Review residential duct design, available static pressure, friction rate, equivalent length, airflow, fittings, and duct sizing.

Manual S: Study residential equipment-selection procedures and the relationship between calculated loads and manufacturer performance data.

Texas Laws and Rules: Become familiar with Chapter 1302 of the Texas Occupations Code and Chapter 75 of the Texas Administrative Code, including license classes, endorsements, contractor responsibilities, and regulatory requirements.

Reference Navigation: The number of books makes organization especially important. Practice identifying the type of question first so you can move directly to the mechanical code, fuel-gas code, Texas law, technical textbook, or ACCA design manual most likely to contain the answer.

How 1 Exam Prep Helps You Reach Your Goal

1 Exam Prep helps Texas Environmental Air Class B candidates organize a broad group of HVAC references into a structured study process. Candidates can focus on high-value topics while learning how the individual books relate to different areas of the examination.

Trade-focused review can reinforce air distribution, refrigeration principles, HVAC systems, combustion air, controls, piping, equipment requirements, service, testing, ventilation, and fuel-gas concepts.

Reference-navigation practice is especially valuable for an open-book examination with multiple code books and technical manuals. Candidates can practice determining whether a question belongs in the IMC, UMC, IFGC, Texas law and rules, Modern Refrigeration and Air Conditioning, Manual J, Manual D, or Manual S.

The design manuals add another important layer of preparation. Manual J supports residential load calculations, Manual D supports duct design, and Manual S supports equipment selection. Used together, they help candidates understand the relationship between building loads, equipment capacity, and air distribution.

1 Exam Prep also helps candidates connect practical field experience with the formal code, design, and regulatory knowledge expected of a licensed contractor. Experienced HVAC professionals may already know how equipment behaves in the field but still benefit from structured review of Texas licensing requirements, code references, system calculations, and formal design procedures.

The goal is to support organized preparation through technical review, code navigation, practical calculations, contractor-law study, and familiarity with the approved reference materials. Preparation is designed to build confidence and exam readiness without guaranteeing a passing score or licensing outcome.

Frequently Asked Questions

Is the Texas Environmental Air Class B exam open book?

Yes. The Texas Environmental Air Class B examination is an open book test.

How many questions are on the exam?

The current examination contains 100 scored questions plus 5 non-scored questions.

How much time is allowed?

The scored portion allows 170 minutes, with an additional 10 minutes for the non-scored questions.

What score is required to pass?

The current passing score is 70%.

Who administers the examination?

The examination is administered through PSI for the Texas Department of Licensing and Regulation.

What can a Texas Class B Environmental Air contractor work on?

A Class B Environmental Air contractor may work on qualifying individual cooling systems of 25 tons or less and heating systems of 1.5 million Btu per hour or less.

What does Environmental Air Conditioning mean?

Environmental Air Conditioning covers treatment of air to control temperature, humidity, cleanliness, ventilation, and circulation for human comfort.

What mechanical codes apply beginning September 1, 2026?

Texas updated its adopted references to include the 2024 International Mechanical Code, 2024 International Fuel Gas Code, and 2024 Uniform Mechanical Code.

Which exam subject has the most questions?

Air Distribution is the largest current technical category, with approximately 15 questions.

Why is Manual J important?

Manual J supports residential heating and cooling load calculations and helps candidates understand how building loads affect HVAC system sizing.

Why is Manual D important?

Manual D addresses residential duct-system design, including airflow, static pressure, friction rate, duct sizing, and distribution-system performance.

Why is Manual S important?

Manual S addresses residential equipment selection and helps match equipment performance to the heating and cooling loads determined during system design.

Can approved books be highlighted and tabbed?

Approved references may be highlighted, underlined, contain notes made before the examination, and use permitted permanent indexing. Temporary removable tabs and loose additional papers are not allowed.

Can I write in my books during the exam?

No. Candidates may not add writing, highlighting, underlining, or indexing to examination references during the testing session.

What should I focus on during final preparation?

Focus on air distribution, equipment requirements and design, service, testing, HVACR systems, refrigeration fundamentals, combustion air, controls, fuel-gas requirements, load calculations, duct design, equipment selection, and Texas licensing laws and rules.