Connecticut Limited Heating Cooling Journeyperson (D-4) - Books & Courses Rental Package

Prepare for the Connecticut Limited Heating Cooling Journeyperson (D-4) examination with a convenient rental package that combines the approved exam-room references with structured online course access. This package is designed for refrigeration and cooling professionals who want an organized way to review the trade subjects, practice using the required references, and prepare for Connecticut’s open-book journeyperson examination.

The D-4 examination covers refrigeration systems used in food storage, air conditioning, and special-process applications. Candidates are expected to understand refrigeration principles, refrigerants, piping and tubing, system components, controls, valves, electrical wiring, testing, inspection, maintenance, troubleshooting, and workplace safety.

This rental package includes the International Mechanical Code, 2021; Code of Federal Regulations – 29 CFR Part 1926 covering OSHA construction requirements; and Modern Refrigeration and Air Conditioning, 22nd Edition. These references support the major technical and safety areas included in the D-4 examination outline.

All rental books included with the package are highlighted and tabbed before delivery. The prepared highlighting draws attention to useful code provisions, technical explanations, safety requirements, definitions, tables, diagrams, and commonly reviewed subjects. Permanent tabs help candidates move between major chapters and examination topics more efficiently.

The included course provides an organized structure for studying refrigeration, controls, piping, system components, maintenance, and safety. Candidates can work through the material by subject while practicing with the same highlighted and tabbed books they plan to bring into the examination center.

The rental cost is $840, plus a $250 refundable book deposit, for a total package price of $1,090. The deposit is refundable when the rental books are returned within the rental period in similar condition.

Please allow up to 15 business days for Book & Course Rental Package orders.

Exam Details

The Connecticut Limited Heating-Cooling Journeyperson (D-4) examination contains 40 questions. Candidates are allowed 1½ hours to complete the test, and a minimum score of 70 percent is required to pass.

The published D-4 examination outline includes the following subject areas:

• Refrigeration and Refrigerants: 12 questions
• Piping and Tubing: 5 questions
• Components: 7 questions
• Controls, Valves, and Wiring: 7 questions
• Tests, Inspection, and Maintenance: 5 questions
• Safety: 4 questions

Refrigeration and refrigerants form the largest examination category. Candidates should understand the basic refrigeration cycle, heat transfer, changes of state, pressure-temperature relationships, refrigerant conditions, and the movement of refrigerant through the major parts of a cooling system.

The components category may include compressors, condensers, evaporators, metering devices, receivers, accumulators, filter-driers, heat exchangers, motors, fans, and other refrigeration equipment. Candidates should understand the purpose of each component and how a change in one part of the system can affect overall operation.

Controls, valves, and wiring account for seven questions. Preparation may include thermostats, pressure controls, temperature controls, relays, contactors, capacitors, motors, overload devices, protective controls, solenoid valves, service valves, wiring diagrams, and common equipment operating sequences.

Piping and tubing questions may address materials, fittings, joining methods, supports, insulation, routing, pressure considerations, and refrigeration piping practices. Candidates should understand how piping arrangements can affect refrigerant movement, oil return, system capacity, and equipment performance.

Tests, inspection, and maintenance topics may include leak testing, evacuation, charging, pressure readings, temperature measurements, preventive maintenance, equipment inspection, system diagnosis, and troubleshooting. Safety questions may involve OSHA construction requirements and accepted practices for working around tools, ladders, electrical equipment, refrigerants, and jobsite hazards.

With 90 minutes available for 40 questions, candidates have an average of slightly more than two minutes per question. This time includes reading the question, identifying the subject, choosing the appropriate reference, locating the relevant information, and selecting an answer.

Open Book Test

The Connecticut D-4 Limited Heating-Cooling Journeyperson examination is an open-book test. Candidates may bring the approved references included in this rental package into the examination center under the applicable testing rules.

The International Mechanical Code supports code-based refrigeration and mechanical-system questions. OSHA 29 CFR Part 1926 supports construction-safety questions. Modern Refrigeration and Air Conditioning supports technical questions involving refrigeration principles, refrigerants, system components, piping, controls, valves, wiring, inspection, maintenance, and troubleshooting.

Approved references may be highlighted, underlined, annotated, and indexed before the examination session. Permanent tabs are permitted. Temporary tabs, removable notes, and loose papers are not allowed.

Candidates may not write in the books during the examination. Questions and answers may not be written inside the references, and additional sheets may not be attached to or inserted into the approved materials.

All books in this rental package arrive highlighted and tabbed. Candidates should review the preparation system before exam day, locate the sections identified by each tab, and practice using the index when a subject is not directly marked.

A silent, nonprinting, non-programmable calculator may be used in the examination center. Candidates should become familiar with an acceptable calculator before the test and practice any refrigeration, electrical, or trade calculations that may be part of their preparation.

An open-book examination still requires technical knowledge and preparation. Searching randomly through unfamiliar references can consume valuable time. Candidates should practice identifying the likely source before opening a book. A mechanical-code question may lead to the International Mechanical Code, a safety question may require OSHA, and a refrigeration or equipment question may be found in Modern Refrigeration and Air Conditioning.

Licensing Steps

1. Review the D-4 classification. Confirm that the Connecticut Limited Heating-Cooling Journeyperson credential matches the refrigeration and cooling work you intend to perform.
2. Complete the required training pathway. Applicants must meet Connecticut’s applicable apprenticeship, experience, education, or equivalent-training requirements.
3. Prepare the journeyperson application. Complete the applicable Connecticut Department of Consumer Protection application and gather the required supporting documents.
4. Submit qualification records. Provide apprenticeship records, employment verification, classroom documentation, or other evidence required for the applicant’s licensing pathway.
5. Receive examination eligibility. The Department of Consumer Protection reviews the application and determines whether the candidate is approved to take the D-4 examination.
6. Schedule the examination. Follow the testing provider’s registration and scheduling procedures after eligibility is granted.
7. Study with the rental package. Use the highlighted and tabbed references with the included online course to prepare for each examination category.
8. Take the D-4 examination. Complete the 40-question test within the 1½-hour time limit.
9. Complete license issuance requirements. Follow Connecticut’s instructions after passing the examination and submit any remaining documents or licensing fees.
10. Return the rental books. Return all books within the rental period in similar condition to qualify for the refundable $250 deposit.

Passing the examination does not automatically issue the license. Candidates must complete the state application process, satisfy the applicable experience and training requirements, pass the examination, and receive approval for license issuance.

State Requirements

The Connecticut D-4 credential is a Limited Heating-Cooling Journeyperson license associated with refrigeration systems used in food storage, air conditioning, and special-process applications. The license holder may perform work within the established D-4 scope while employed by a properly licensed contractor.

The authorized work may include installation, repair, replacement, maintenance, and alteration of qualifying refrigeration and cooling systems. Candidates should review the official Connecticut scope of work before applying to confirm that the D-4 classification covers their intended employment duties.

The D-4 classification does not provide independent contracting authority. A licensed D-4 journeyperson must work under the employment of a contractor who holds the appropriate Connecticut credential for the work being performed.

Applicants must satisfy the Connecticut Department of Consumer Protection’s applicable training, apprenticeship, experience, education, and examination requirements. Supporting records may be required to document classroom instruction, supervised work, apprenticeship completion, or equivalent qualifications.

Applicants who completed training or gained experience outside Connecticut should follow the state’s procedures for equivalent experience or an equivalent out-of-state license. The Department of Consumer Protection determines whether the submitted qualifications meet Connecticut’s requirements.

Connecticut offers several heating, cooling, refrigeration, fuel gas, piping, and sheet metal license classifications. Candidates should choose the credential that accurately reflects the work they intend to perform rather than relying only on similarities between license titles.

Reference Books

• Included Rental Book: International Mechanical Code, 2021
  This approved exam-room code addresses mechanical and refrigeration systems, refrigerant piping, equipment installation, machinery rooms, ventilation, system safety, testing, and related mechanical requirements. The rental copy is highlighted and tabbed to support organized study and faster reference navigation.
• Included Rental Book: Code of Federal Regulations – 29 CFR Part 1926 (OSHA)
  This approved federal construction-safety reference covers personal protective equipment, electrical hazards, ladders, scaffolds, fall protection, hand and power tools, material handling, excavation, and general jobsite practices. The rental copy is highlighted and tabbed for focused safety review.
• Included Rental Book: Modern Refrigeration and Air Conditioning, 22nd Edition
  This comprehensive technical reference covers refrigeration principles, refrigerants, compressors, condensers, evaporators, metering devices, piping, valves, electrical controls, installation, testing, maintenance, service, and troubleshooting. The rental copy is highlighted and tabbed.

Exam Room Approved Books

The following highlighted and tabbed rental references are included for use during the Connecticut D-4 examination:

• International Mechanical Code, 2021
  Use this reference for refrigeration-system code provisions, refrigerant piping, machinery rooms, ventilation, equipment installation, testing, and mechanical safety requirements.
• Code of Federal Regulations – 29 CFR Part 1926 (OSHA)
  Use this reference for construction-safety questions involving protective equipment, electrical hazards, ladders, fall protection, tools, material handling, and jobsite procedures.
• Modern Refrigeration and Air Conditioning, 22nd Edition
  Use this reference for refrigeration principles, refrigerants, system components, piping, tubing, controls, valves, wiring, inspection, maintenance, and troubleshooting.

Candidates are responsible for bringing their approved references to the examination center. The testing center does not provide every candidate with a personal set of books.

The included highlighting and tabbing provide an organized starting point. Candidates should study with the rental books throughout the course-access period so the location of major subjects, tables, diagrams, and technical explanations becomes familiar.

Test Information and Study Materials

A productive D-4 study plan should begin with refrigeration and refrigerants because this category contains 12 of the 40 examination questions. Review the refrigeration cycle, heat transfer, refrigerant states, pressure-temperature relationships, and normal equipment operating conditions.

Continue with system components. Learn how compressors, condensers, evaporators, metering devices, receivers, accumulators, filter-driers, motors, and fans contribute to system operation. Consider how equipment failures can affect pressure, temperature, airflow, capacity, and refrigerant movement.

Controls, valves, and wiring should receive focused attention. Practice recognizing electrical symbols, reading basic wiring diagrams, identifying control functions, and understanding how temperature, pressure, and protective controls affect the operating sequence.

Use the International Mechanical Code to review refrigeration-system requirements, refrigerant piping, equipment installation, machinery rooms, ventilation, testing, and mechanical safety. Pay attention to definitions, exceptions, notes, and table headings.

Use OSHA 29 CFR Part 1926 for safety preparation. Focus on personal protective equipment, electrical hazards, ladders, fall protection, hand and power tools, material handling, and safe construction-site practices.

Use Modern Refrigeration and Air Conditioning to reinforce refrigeration principles, refrigerants, components, piping, controls, electrical systems, charging, evacuation, leak testing, inspection, maintenance, and troubleshooting.

The package includes 6 months of course access. Candidates can use the course to create a study schedule, review technical topics, complete practice-oriented preparation, and build familiarity with the highlighted and tabbed references.

Timed practice can help candidates improve their exam strategy. Read each question carefully, identify the subject, select the most likely reference, use the permanent tabs or index, and review the complete supporting material before choosing an answer.

How 1 Exam Prep Helps You Reach Your Goal

1 Exam Prep helps Connecticut D-4 candidates prepare with an organized combination of highlighted rental books and online course access. The package brings the approved references together so candidates can focus on technical review, practice, and open-book navigation.

Every rental book is highlighted and tabbed to support more efficient study. Candidates can use the prepared references to identify major chapters, locate technical explanations, review safety requirements, and practice finding information under timed conditions.

Trade-focused preparation supports the primary D-4 subjects, including refrigeration, refrigerants, piping, tubing, components, controls, valves, wiring, testing, inspection, maintenance, and workplace safety.

The six-month course structure helps candidates divide the examination material into manageable study areas. Practice-oriented review can reveal weaker topics and provide a clearer direction for additional preparation.

Reference-navigation guidance helps candidates learn which book applies to each subject. Developing a repeatable process for choosing a reference, using an index, and reading the complete supporting passage can improve organization during the open-book exam.

No exam-preparation package can guarantee a passing score, application approval, or license issuance. Candidates remain responsible for meeting Connecticut’s qualification requirements, completing the application process, preparing for the examination, and satisfying all licensing requirements.

FAQ Section

What is included in the Books & Courses Rental Package?

The package includes three highlighted and tabbed rental books and 6 months of course access for the Connecticut D-4 journeyperson examination.

What is the total package price?

The rental cost is $840, plus a refundable $250 book deposit. The total package price is $1,090.

How does the refundable deposit work?

The $250 deposit is refundable when all rental books are returned within the rental period in similar condition.

Are the rental books highlighted and tabbed?

Yes. All three books included with the package are highlighted and tabbed before delivery.

How long should I allow for the order?

Please allow up to 15 business days for Book & Course Rental Package orders.

How long is the course available?

The package includes 6 months of course access.

Is the Connecticut D-4 examination open book?

Yes. The D-4 examination is open book, and candidates may bring the approved references into the examination center under the applicable testing rules.

How many questions are on the D-4 examination?

The examination contains 40 questions. Candidates have 1½ hours to complete the test and must earn a minimum score of 70 percent.

What is the largest examination category?

Refrigeration and refrigerants are the largest category, accounting for 12 questions. Components and controls, valves, and wiring each account for seven questions.

Does the D-4 license allow independent contracting?

No. The D-4 credential is a journeyperson license. The license holder must perform authorized work while employed by a properly licensed contractor.

Does purchasing this package guarantee a license?

No. Applicants must meet Connecticut’s qualification requirements, pass the examination, complete the licensing process, and receive approval from the appropriate state authority.