Connecticut Limited Warm Air, Air Conditioning and Refrigeration System Contractor (D-1) Highlighted & Tabbed Book Package

Prepare for the Connecticut Limited Warm Air, Air Conditioning and Refrigeration System Contractor (D-1) examination with a complete collection of highlighted and permanently tabbed trade references. This package is designed for contractor candidates who want an organized way to study warm-air heating, air conditioning, refrigeration, fuel gas, ductwork, load calculations, ventilation, controls, safety, and related mechanical subjects.

The Connecticut D-1 trade examination requires more than practical HVAC experience. Candidates must also be able to locate code provisions, formulas, sizing information, definitions, technical tables, installation requirements, and equipment information within a limited testing period. Studying with the correct references and becoming familiar with their organization can make open-book preparation more efficient.

This package includes the International Mechanical Code, 2021; Manual J - Residential Load Calculations, reprinted 2016, Eighth Full Edition; Manual N - Commercial Load Calculation for Small Commercial Buildings, 5th Edition; NFPA 54 - National Fuel Gas Code Handbook, 2012; Code of Federal Regulations - 29 CFR Part 1926 (OSHA); Modern Refrigeration and Air Conditioning, 22nd Edition; a Ductulator; HVAC Duct Construction Standards, Metal and Flexible, 2005, 3rd Edition; and NFPA 58 - Liquefied Petroleum Gas Code, 2014.

Every included book is highlighted and permanently tabbed before delivery. Important chapters, definitions, formulas, code provisions, load-calculation sections, ductwork topics, fuel-gas subjects, refrigeration material, safety requirements, technical tables, and frequently reviewed sections are marked to create an organized starting point for study.

The included highlighting can help draw attention to useful provisions and technical material, while the permanent tabs create a practical navigation system for major subjects. Candidates should still review each marked section carefully and become familiar with the relationship between the tabs, the indexes, and the surrounding content.

Highlighted and tabbed references are most useful when they are used throughout preparation. Candidates should practice identifying the subject of a question, selecting the most likely reference, locating the correct chapter or table, and reading the complete supporting section before choosing an answer.

The D-1 examination is open book, but the testing period is limited. Candidates who wait until exam day to open the references may have difficulty locating information quickly. Repeated navigation practice can help reduce unnecessary searching and support better time management.

This product is a highlighted and tabbed book package. It does not include online course access, book rental, Application Service, a refundable deposit, the Connecticut contractor Business and Law book, business formation, or EIN filing.

Please allow up to 15 business days for tabbed and highlighted book package orders.

What You Get

Exam Details

The Connecticut Limited Warm Air, Air Conditioning and Refrigeration System Contractor (D-1) trade examination contains 70 questions. Candidates are allowed three hours to complete the examination, and a minimum score of 70 percent is required to pass.

The D-1 examination content outline includes the following categories:

• Insulation: 1 question
• Hangers and Supports: 2 questions
• Sound, Vibration and Seismic Control: 1 question
• Heating and Cooling Principles: 5 questions
• Refrigerants and Refrigeration: 8 questions
• Testing, Adjusting and Balancing: 2 questions
• Controls: 5 questions
• Machine Room: 1 question
• Air-Conditioning and Heat-Pump Equipment: 5 questions
• Furnaces and Heaters: 4 questions
• Chimneys, Flues and Vents: 2 questions
• Combustion Air: 2 questions
• Fuel Gas Systems: 10 questions
• Ducts: 6 questions
• Chillers: 3 questions
• Ventilation and Exhaust: 3 questions
• Safety: 4 questions
• Load Calculations: 6 questions

Fuel-gas systems are the largest examination category, accounting for 10 of the 70 questions. Candidates should understand fuel-gas piping, pressure, regulators, appliance connections, testing, combustion air, venting, sizing procedures, and related safety requirements.

Refrigerants and refrigeration account for eight questions. Preparation should include the refrigeration cycle, refrigerants, compressors, condensers, evaporators, metering devices, pressure-temperature relationships, charging principles, system operation, maintenance, and troubleshooting.

Ducts and load calculations each account for six questions. Candidates should review duct sizing, airflow, friction rate, velocity, fittings, sealing, reinforcement, residential load calculations, small-commercial load calculations, heat gain, heat loss, and equipment-sizing considerations.

Heating and cooling principles, controls, and air-conditioning and heat-pump equipment each account for five questions. Candidates should understand heat transfer, system operation, thermostats, relays, operating controls, safety controls, heat pumps, furnaces, and cooling equipment.

With three hours available for 70 questions, candidates have an average of approximately two minutes and thirty-four seconds per question. This time includes reading the question, identifying the topic, selecting the appropriate reference, locating the information, and choosing an answer.

Connecticut contractor candidates may also be required to pass the separate Business and Law examination. The business examination uses its own approved reference, which is not included in this highlighted and tabbed trade book package.

Open Book Test

The Connecticut D-1 trade examination is an open-book test. Candidates may bring approved references into the testing center under the applicable examination rules.

The references included in this package support the D-1 trade examination and may be used to prepare for code, load-calculation, fuel-gas, refrigeration, ductwork, equipment, ventilation, and safety questions.

Approved references may be highlighted, underlined, annotated, and indexed before the examination. Permanent tabs may be used to identify chapters, definitions, formulas, tables, fuel-gas topics, refrigeration sections, ductwork requirements, safety provisions, and load-calculation material.

Temporary tabs, removable notes, loose papers, and inserted pages are not permitted. Candidates may not write in the references during the examination, and examination questions or answers may not be recorded inside the books.

All included books arrive highlighted and permanently tabbed. Candidates should review every tab before exam day and become familiar with the marked sections. Prepared references provide the greatest value when the candidate understands what each tab identifies and how to use the index and surrounding material.

A practical open-book strategy begins with identifying the main subject. Mechanical-code questions may lead to the International Mechanical Code. Residential load-calculation questions may require Manual J, while qualifying small-commercial load calculations may require Manual N.

Natural-gas questions may lead to NFPA 54, while LP gas questions may require NFPA 58. Safety questions may require OSHA 29 CFR Part 1926. Duct-sizing questions may involve the Ductulator, and duct-construction questions may require HVAC Duct Construction Standards.

Technical questions involving refrigeration, air conditioning, heating, heat pumps, controls, equipment, operation, maintenance, and troubleshooting may be supported by Modern Refrigeration and Air Conditioning.

Candidates should use the permanent tabs together with the table of contents, index, chapter headings, diagrams, and technical tables. Reading the complete supporting section is essential because exceptions, notes, table headings, and surrounding provisions may affect the correct answer.

Licensing Steps

1. Review the D-1 license scope. Confirm that the Connecticut Limited Warm Air, Air Conditioning and Refrigeration System Contractor classification matches the services you intend to provide.
2. Document the qualifying pathway. Gather records showing the applicable education, on-the-job training, license history, and qualifying contractor-level experience.
3. Complete the contractor application. Submit the applicable D-1 application and supporting documentation to the Connecticut Department of Consumer Protection.
4. Receive examination eligibility. Connecticut reviews the applicant’s qualifications and determines whether the candidate may proceed to testing.
5. Prepare for the D-1 trade examination. Study the highlighted and tabbed references and review the published examination outline.
6. Prepare for Business and Law. Obtain the separate Connecticut contractor business reference and prepare for the applicable Business and Law examination.
7. Schedule the examinations. Follow the testing provider’s registration and scheduling procedures after eligibility is granted.
8. Complete the required examinations. Pass the D-1 trade examination and the applicable Connecticut contractor Business and Law examination.
9. Complete license-issuance requirements. Submit passing results and any remaining documents or licensing fees required by Connecticut.

Passing the examinations does not automatically issue the D-1 license. Applicants must complete Connecticut’s qualification, application, examination, documentation, and license-issuance requirements.

State Requirements

The Connecticut D-1 credential is a limited contractor license associated with warm-air heating, air-conditioning, and refrigeration systems. The classification covers qualifying installation, repair, replacement, maintenance, and alteration work involving these systems, including necessary piping used to convey heating or cooling media and associated pumping equipment.

Applicants must qualify through an accepted Connecticut licensing pathway and provide the applicable documentation. Connecticut may review classroom education, supervised on-the-job training, occupational license history, contractor experience, and other supporting records.

The D-1 contractor license is issued to an individual. A business entity and the occupational contractor license serve different purposes. The individual license identifies the person authorized to contract for and oversee regulated D-1 work.

Connecticut contractor candidates must complete the applicable trade examination and the contractor Business and Law examination. Passing both examinations does not automatically issue the license because all application, qualification, documentation, and license-issuance requirements must also be satisfied.

The D-1 classification is limited to its authorized scope. It does not automatically authorize unrelated electrical, plumbing, sheet-metal, unlimited heating, or other regulated work outside the classification. Additional credentials may be required when a project includes work beyond the D-1 scope.

Applicants should review the applicable Connecticut license scope before applying. Selecting the correct classification helps ensure that the credential matches the type of contracting work the applicant plans to perform.

Reference Books

• International Mechanical Code, 2021
  This mechanical code covers equipment installation, refrigeration machinery rooms, ventilation, combustion air, ducts, chimneys, vents, piping, and related requirements. The included copy is highlighted and permanently tabbed.
• Manual J - Residential Load Calculations, reprinted 2016, Eighth Full Edition
  This reference supports residential heating and cooling load-calculation preparation, including heat gain, heat loss, building characteristics, and equipment-sizing inputs. The included copy is highlighted and permanently tabbed.
• Manual N - Commercial Load Calculation for Small Commercial Buildings, 5th Edition
  This reference supports heating and cooling load calculations for qualifying small-commercial buildings. The included copy is highlighted and permanently tabbed.
• NFPA 54 - National Fuel Gas Code Handbook, 2012
  This reference covers fuel-gas piping, sizing, appliance installation, pressure regulation, combustion air, venting, testing, and safety requirements. The included copy is highlighted and permanently tabbed.
• Code of Federal Regulations - 29 CFR Part 1926 (OSHA)
  This safety reference supports preparation involving personal protective equipment, fall protection, ladders, scaffolds, excavation, electrical hazards, and construction-site responsibilities. The included copy is highlighted and permanently tabbed.
• Modern Refrigeration and Air Conditioning, 22nd Edition
  This technical reference covers refrigeration, air conditioning, heating, heat pumps, controls, equipment, system operation, maintenance, and troubleshooting. The included copy is highlighted and permanently tabbed.
• Ductulator
  This duct-sizing tool supports preparation involving airflow, velocity, friction rate, and distribution-system calculations.
• HVAC Duct Construction Standards, Metal and Flexible, 2005, 3rd Edition
  This reference covers duct materials, reinforcement, fittings, sealing, supports, fabrication, and construction requirements. The included copy is highlighted and permanently tabbed.
• NFPA 58 - Liquefied Petroleum Gas Code, 2014
  This standard covers LP gas containers, storage, regulators, piping, installation, equipment, separation requirements, and related safety provisions. The included copy is highlighted and permanently tabbed.

Exam Room Approved Books

The following highlighted and tabbed references and tools are included for D-1 trade examination preparation and applicable exam-room use:

• International Mechanical Code, 2021
  Use this reference for mechanical equipment, refrigeration machinery rooms, ventilation, ducts, combustion air, piping, chimneys, and venting requirements.
• Manual J - Residential Load Calculations, Eighth Full Edition
  Use this reference for residential heating and cooling load-calculation questions.
• Manual N - Commercial Load Calculation for Small Commercial Buildings, 5th Edition
  Use this reference for qualifying small-commercial load-calculation questions.
• NFPA 54 - National Fuel Gas Code Handbook, 2012
  Use this reference for fuel-gas piping, sizing, appliance installation, regulators, combustion air, venting, and testing.
• Code of Federal Regulations - 29 CFR Part 1926 (OSHA)
  Use this reference for construction-safety questions.
• Modern Refrigeration and Air Conditioning, 22nd Edition
  Use this reference for refrigeration, heating, air conditioning, heat pumps, controls, equipment, maintenance, and troubleshooting.
• Ductulator
  Use this tool for duct-sizing, airflow, velocity, and friction-rate calculations.
• HVAC Duct Construction Standards, Metal and Flexible, 2005, 3rd Edition
  Use this reference for duct construction, reinforcement, sealing, fittings, and support requirements.
• NFPA 58 - Liquefied Petroleum Gas Code, 2014
  Use this standard for LP gas containers, regulators, piping, storage, equipment, and safety requirements.

Candidates are responsible for bringing their approved materials to the testing center. The examination location does not provide each candidate with a complete personal reference set.

All books included in this package are highlighted and permanently tabbed. Candidates should inspect the references before exam day and make sure the tabs, highlighting, and annotations comply with the applicable testing rules.

Test Information and Study Materials

A productive D-1 study plan should begin with fuel-gas systems, refrigeration, load calculations, and ducts because these subjects represent a substantial portion of the examination.

Practice fuel-gas piping and sizing with NFPA 54, including the applicable sizing method and table navigation. Review LP gas containers, storage, regulators, piping, equipment, and safety provisions in NFPA 58.

Use Manual J and Manual N to review load-calculation concepts. Candidates should understand heat gain, heat loss, design conditions, building characteristics, equipment-sizing inputs, and the differences between residential and qualifying small-commercial calculations.

Use the Ductulator and HVAC Duct Construction Standards to review airflow, friction, velocity, duct sizing, materials, reinforcement, fittings, sealing, and supports.

Review the refrigeration cycle, refrigerants, compressors, condensers, evaporators, metering devices, pressure-temperature relationships, controls, heat pumps, chillers, furnaces, and troubleshooting in Modern Refrigeration and Air Conditioning.

Use the International Mechanical Code for formal installation and mechanical-system requirements. Use OSHA 29 CFR Part 1926 for construction-safety preparation involving personal protective equipment, ladders, scaffolds, fall protection, excavation, and workplace hazards.

Timed reference practice should include identifying the likely book before starting the search. Use the permanent tabs to reach a major section, then use the index, chapter headings, formulas, tables, and diagrams to locate the precise supporting information.

Review missed practice questions carefully. Locate the supporting code provision, formula, or technical explanation, identify why the original answer was incorrect, and study related material that may appear in another form on the examination.

How 1 Exam Prep Helps You Reach Your Goal

1 Exam Prep helps Connecticut D-1 contractor candidates begin their preparation with an organized collection of highlighted and tabbed examination references. The package brings together mechanical, fuel-gas, safety, load-calculation, ductwork, refrigeration, heating, and air-conditioning resources in one coordinated set.

Trade-focused review helps candidates connect each examination subject with the appropriate reference. Mechanical questions can be researched in the International Mechanical Code, load calculations can be matched with Manual J or Manual N, and fuel-gas questions can be directed to NFPA 54 or NFPA 58.

Practice-oriented preparation helps candidates build confidence with calculations, technical tables, code provisions, and equipment questions. Missed questions can be researched in the included references to reinforce both subject knowledge and navigation skills.

The highlighted and tabbed books provide a practical study framework. Highlighting draws attention to useful material, while permanent tabs help candidates move between major chapters, formulas, definitions, tables, and technical subjects.

Reference-navigation practice can support better time management during the three-hour examination. Candidates can learn how to select the correct book, locate effective index terms, interpret tables, and review complete provisions before choosing an answer.

No highlighted and tabbed book package can guarantee examination eligibility, a passing score, application approval, or contractor license issuance. Consistent study, qualifying experience, reference familiarity, technical understanding, and effective time management remain important parts of the Connecticut D-1 licensing process.

FAQ Section

What books are included in this package?

The package includes the International Mechanical Code, Manual J, Manual N, NFPA 54, OSHA 29 CFR Part 1926, Modern Refrigeration and Air Conditioning, HVAC Duct Construction Standards, NFPA 58, and a Ductulator.

Are the included books highlighted and tabbed?

Yes. Every included book is highlighted and permanently tabbed before delivery.

How long should I allow for the order?

Please allow up to 15 business days for tabbed and highlighted book package orders.

Is the Connecticut D-1 examination open book?

Yes. Candidates may bring approved references and permitted tools into the testing center under the applicable examination rules.

How many questions are on the D-1 examination?

The D-1 trade examination contains 70 questions. Candidates have three hours to complete the test and must earn a minimum score of 70 percent.

What is the largest D-1 examination category?

Fuel-gas systems are the largest category, accounting for 10 questions. Refrigerants and refrigeration follow with eight questions.

Is a Ductulator included?

Yes. A Ductulator is included for duct-sizing, airflow, velocity, and friction-rate preparation.

Does this package include the Business and Law book?

No. The Connecticut contractor Business and Law reference is not included in this highlighted and tabbed D-1 trade book package.

Does this package include online course access?

No. This product is a highlighted and tabbed book package and does not include online course access.

Is this a rental package?

No. This product is not identified as a rental package and does not include a refundable book deposit.

Does this package include Application Service?

No. Application Service is not included with this highlighted and tabbed book package.

Does purchasing this package guarantee a D-1 license?

No. Applicants must meet Connecticut’s qualification requirements, receive examination eligibility, pass the required examinations, complete the licensing process, and receive state approval.