Prepare for the Washington DC Master Refrigeration & Air Conditioning Mechanical Limited examination with a focused book package designed around the mechanical-code and HVACR subjects covered on the current District of Columbia exam. This package includes the 2012 International Mechanical Code and Modern Refrigeration and Air Conditioning, 22nd Edition for study of refrigeration theory, air-conditioning systems, piping, equipment, airflow, controls, refrigerants, safety, maintenance, and repair.
The District of Columbia regulates refrigeration and air-conditioning mechanics through the Board of Industrial Trades. The limited master credential applies to qualifying refrigeration and air-conditioning work involving equipment below the District's limited-license horsepower threshold.
The current PSI examination is identified as 322 Washington DC Master Refrigeration and Air Conditioning Mechanic Limited. It covers refrigeration and air-conditioning theory, system types, terminology, piping, compressors, condensers, evaporators, chillers, cooling towers, heat pumps, appliances, conditioned-air systems, ductwork, electrical fundamentals, controls, refrigerants, operating procedures, safety, maintenance, and repairs.
The 2012 International Mechanical Code provides the mechanical-code foundation for preparation. It includes requirements affecting refrigeration systems, mechanical appliances, ventilation, duct systems, combustion air, piping, condensate disposal, equipment installation, and other mechanical-system requirements.
Modern Refrigeration and Air Conditioning, 22nd Edition supports the technical side of preparation with detailed HVACR material covering refrigeration cycles, system components, heat transfer, electrical controls, refrigerants, service procedures, troubleshooting, air-conditioning systems, and equipment operation.
The Washington DC Master Refrigeration and Air Conditioning Mechanic Limited examination is an open-book test. Candidates should prepare not only by learning HVACR concepts but also by practicing efficient reference navigation so they can locate applicable mechanical-code requirements within the available testing time.
The current examination is identified as 322 Washington DC Master Refrigeration and Air Conditioning Mechanic Limited.
The examination contains 70 multiple-choice questions and provides candidates with a 3-hour time limit.
The current examination content outline is:
Refrigerant and Condensate Piping is the largest individual category at 18%. Theory, System Types, Terminology, and General Requirements represent 16%. Major HVACR equipment and Conditioned Air/Duct Systems each account for another 15%.
The exam therefore requires broad knowledge rather than concentration on one single subject. Candidates should understand refrigeration theory and equipment operation while also being able to work with mechanical-code provisions affecting piping, ducts, ventilation, combustion air, appliances, and refrigeration systems.
With 180 minutes available for 70 questions, candidates have an average of approximately 2.6 minutes per question. Efficient reference navigation and familiarity with common HVACR calculations can help candidates manage the exam effectively.
The Washington DC Master Refrigeration and Air Conditioning Mechanic Limited examination is an open book test.
The current PSI examination bulletin identifies the 2012 International Mechanical Code as an approved reference. It also lists Modern Refrigeration and Air Conditioning, 2004 among the approved exam-room references for examination 322.
The Modern Refrigeration and Air Conditioning, 22nd Edition included in this package is intended as a comprehensive HVACR study resource. Candidates should use the specific edition listed by PSI when selecting books to bring into the examination room.
The 2012 International Mechanical Code is particularly important for questions involving refrigeration piping, mechanical equipment, ductwork, ventilation, combustion air, condensate, appliances, equipment clearances, and other installation requirements.
Open-book testing requires familiarity rather than simple access to the books. Candidates should practice determining whether a question calls for a mechanical-code lookup or technical HVACR knowledge before beginning a search.
For example, a question about the operation of a compressor may rely primarily on refrigeration theory, while a question involving refrigeration-system installation, piping, equipment location, or ventilation may require the International Mechanical Code.
Reference books are subject to PSI examination-center rules and inspection. Candidates should organize their approved references before exam day and practice using them during timed study sessions.
The District of Columbia Board of Industrial Trades regulates refrigeration and air-conditioning mechanics and contractors. Candidates seeking a Master Refrigeration and Air Conditioning Mechanic Limited credential must satisfy the experience, certification, examination, and application requirements that apply to the limited master category.
The individual Master Refrigeration and Air Conditioning Mechanic Limited credential should be distinguished from a Refrigeration and Air Conditioning Contractor Limited license. A contractor credential is a separate business-related license with its own requirements.
Washington DC is a federal district rather than a state, but refrigeration and air-conditioning work is regulated through the District of Columbia Board of Industrial Trades.
District law distinguishes between regular and limited master refrigeration and air-conditioning mechanics. A Master Mechanic Limited applicant must establish at least five consecutive years of qualifying experience immediately preceding the application.
The experience must involve installing, maintaining, repairing, and replacing refrigeration and air-conditioning equipment systems less than 25 compressor horsepower or the equivalent tons of refrigeration in the aggregate.
The qualifying experience must be verified in writing by a master mechanic. This verification establishes that the applicant has performed the type and duration of HVACR work required for the limited master credential.
District law also requires a Master Mechanic Limited applicant to have proof of chlorofluorocarbon certification. Current District licensing instructions identify CFC certification as an applicable requirement for master refrigeration and air-conditioning applicants.
The District's current refrigeration licensing instructions describe limited mechanical work as work performed on equipment at or below 25 compressor horsepower. Candidates should understand this limited classification when choosing between the limited and regular master licensing pathways.
The Board of Industrial Trades requires refrigeration applicants to submit applicable documentation such as CFC certification and employment verification. General application requirements also include a passport-style photograph, government-issued identification, and payment information for applicable fees.
Washington DC Refrigeration and Air Conditioning licenses currently expire on September 30 of even-numbered years. Renewal is handled separately from the initial licensing and examination process.
The individual master mechanic credential is not the same as a Refrigeration and Air Conditioning Contractor Limited license. Businesses performing contracting work must separately satisfy the District's contractor requirements.
Current District trade-contractor requirements include proof of business registration or a Certificate of Good Standing, a designated DC-licensed master tradesperson, and the applicable refrigeration and air-conditioning bond.
Washington DC currently identifies a $5,000 company bond and a $5,000 designated master bond for refrigeration and air-conditioning contracting. Those contractor requirements are separate from the individual examination and master mechanic licensing requirements.
Modern Refrigeration and Air Conditioning, 22nd Edition is included in this package for study and technical review. Candidates should follow PSI's current approved-reference listing when selecting the edition they bring to the testing center.
Theory, System Types, Terminology, and General Requirements account for 16% of the examination. Candidates should review refrigeration cycles, heat transfer, pressure-temperature relationships, sensible and latent heat, superheat, subcooling, system classifications, HVACR terminology, and general mechanical principles.
Understanding how the refrigeration cycle works provides a foundation for many other examination topics. Candidates should understand what happens to refrigerant as it moves through the compressor, condenser, metering device, and evaporator.
Refrigerant and Condensate Piping represents 18%, making it the largest examination category. Review refrigerant pipe materials, routing, sizing concepts, supports, insulation, joints, equipment connections, condensate drains, traps, and mechanical-code provisions affecting piping installations.
Candidates should understand both the technical reason for proper refrigerant piping and the mechanical-code requirements governing installation. Incorrect piping can affect oil return, refrigerant movement, equipment performance, and condensate disposal.
Evaporators, Compressors, Condensers, Chillers, Cooling Towers, Heat Pumps, Heating and AC Appliances account for 15%. Review component operation, equipment relationships, installation considerations, heat-transfer principles, and common service conditions.
Study compressor operation and common compressor types, evaporator heat absorption, condenser heat rejection, heat-pump operation, and the role each component plays in the refrigeration cycle.
Conditioned Air, Supply, Return, Makeup, Combustion Air, Air Ducts, Dampers, and Insulation also represent 15%. Candidates should understand supply and return air, ventilation, makeup air, combustion air, duct materials, duct installation, dampers, insulation, and airflow principles.
Mechanical-code navigation is particularly useful in this area because many duct, ventilation, and combustion-air questions are tied directly to code requirements.
Electrical Fundamentals and Controls represent 9%. Review voltage, current, resistance, motors, transformers, relays, contactors, capacitors, thermostats, switches, control circuits, safety controls, and HVACR wiring diagrams.
Candidates should be comfortable tracing a basic control circuit and recognizing how an electrical component affects system operation. A failed control device can create symptoms that resemble a refrigeration or airflow problem.
Refrigerants account for 10%. Review refrigerant properties, pressure-temperature relationships, refrigerant states, charging principles, recovery concepts, safety, and system performance.
Technical refrigerant knowledge connects directly with compressor, evaporator, and condenser operation. Candidates should understand how changes in pressure, temperature, superheat, subcooling, and charge affect system performance.
Operating Procedures, including Safety represent 9%. Review startup and shutdown procedures, evacuation, charging, leak testing, recovery, pressure hazards, electrical safety, safe tool use, and appropriate personal protective equipment.
Maintenance and Repairs account for 8%. Candidates should understand preventive maintenance, troubleshooting methods, airflow issues, refrigerant problems, electrical faults, component failures, coil condition, filter condition, and general HVACR service procedures.
A practical troubleshooting approach can make technical questions easier. Begin with the reported symptom, identify possible causes, determine what measurements or observations would confirm those causes, and then select the appropriate corrective action.
For example, inadequate cooling may result from restricted airflow, improper refrigerant charge, dirty coils, compressor problems, failed controls, duct leakage, or a metering-device issue. Candidates should learn how system readings and symptoms help distinguish among those possibilities.
Because the examination is limited to three hours, candidates should practice working through questions under timed conditions. Try to answer straightforward technical questions efficiently and reserve longer reference searches for code-specific or calculation-based problems.
When reviewing missed practice questions, determine whether the error involved theory, an incorrect code section, misunderstanding a component, improper troubleshooting logic, a refrigerant concept, or an electrical-control issue. Studying the reason behind an incorrect answer is generally more valuable than simply memorizing the correct choice.
1 Exam Prep supports Washington DC Master Refrigeration & Air Conditioning Mechanical Limited candidates through organized study guidance, HVACR-focused review, practice-oriented preparation, mechanical-code navigation, calculation practice, and troubleshooting-focused study.
The 2012 International Mechanical Code provides the mechanical-code foundation for exam preparation. Working directly with this code helps candidates become familiar with requirements involving refrigeration systems, piping, ventilation, ducts, appliances, combustion air, condensate disposal, and mechanical equipment.
Modern Refrigeration and Air Conditioning, 22nd Edition provides technical study material covering refrigeration theory, system components, electrical fundamentals, controls, refrigerants, heat pumps, air-conditioning systems, maintenance, troubleshooting, and service procedures.
A structured study approach can prioritize preparation according to the official exam weighting. Refrigerant and Condensate Piping deserves significant attention at 18%, followed by Theory and General Requirements at 16%, equipment at 15%, and conditioned-air and duct subjects at 15%.
Refrigerants, Electrical Fundamentals and Controls, Operating Procedures and Safety, and Maintenance and Repairs should also remain part of a complete preparation schedule.
1 Exam Prep focuses on helping candidates strengthen HVACR knowledge, improve reference-navigation skills, develop troubleshooting ability, and build an organized study routine without guaranteeing a particular examination score or licensing outcome.
The current examination contains 70 multiple-choice questions.
Candidates receive a 3-hour time limit.
Yes. The current examination is an open book test.
The current PSI examination bulletin identifies the 2012 International Mechanical Code as an approved reference.
Yes. This package includes Modern Refrigeration and Air Conditioning, 22nd Edition as a comprehensive HVACR study resource.
The current PSI bulletin specifically identifies Modern Refrigeration and Air Conditioning, 2004 as an approved exam-room reference for examination 322. The 22nd Edition included in this package is intended for study and technical review.
Refrigerant and Condensate Piping is the largest category at 18%.
District licensing information identifies limited work as refrigeration and air-conditioning work performed on equipment at or below 25 compressor horsepower.
District law requires at least five consecutive years of qualifying refrigeration and air-conditioning experience immediately before application, verified in writing by a master mechanic.
Yes. District law requires proof of chlorofluorocarbon certification for a Master Refrigeration and Air Conditioning Mechanic Limited applicant.
Yes. Electrical Fundamentals and Controls represent 9% of the current examination outline.
Yes. Conditioned air, supply and return air, makeup air, combustion air, ducts, dampers, and insulation represent 15% of the examination.
Licensing is regulated through the District of Columbia Board of Industrial Trades.
The Washington DC Master Refrigeration and Air Conditioning Mechanic Limited examination is administered through PSI.
These licenses currently expire on September 30 of even-numbered years.
No. The individual Master Refrigeration and Air Conditioning Mechanic Limited credential and the Refrigeration and Air Conditioning Contractor Limited credential are separate. A business performing contracting work must satisfy the District's applicable contractor requirements.
Focus on refrigerant and condensate piping, refrigeration theory, major HVACR equipment, duct systems, airflow, electrical fundamentals, controls, refrigerants, operating procedures, safety, maintenance, troubleshooting, and efficient navigation of the 2012 International Mechanical Code.
This package combines the 2012 International Mechanical Code with Modern Refrigeration and Air Conditioning, 22nd Edition to support mechanical-code study and comprehensive HVACR preparation. Together, the books provide a strong foundation for piping, refrigeration theory, equipment, air distribution, controls, refrigerants, safety, maintenance, troubleshooting, and open-book exam preparation.
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