LOUISIANA HVAC CONTRACTOR EXAM PRACTICE QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALE 2027 Q&A| INSTANT
DOWNLOAD PDF.– QUESTIONS AND ANSWERS | VERIFIED AND WELL DETAILED
ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
Refrigeration Cycle Fundamentals and Components
HVAC System Installation, Maintenance, and Repair
Ductwork Design, Installation, and Air Distribution
Fuel Gas Piping and Combustion Appliance Venting
Refrigerant Handling, Recovery, and Environmental Compliance
Mechanical Code Compliance and Regulatory Requirements
Electrical Systems for HVAC Equipment
Load Calculations and System Sizing
Safety Procedures and Professional Standards
Introduction
The Louisiana HVAC Contractor Examination assesses the knowledge and
competency required for licensure in the heating, air conditioning, ventilation, duct
work, and refrigeration trade. Candidates must demonstrate understanding of
mechanical codes, refrigerant handling regulations, system design principles, and
safe installation practices. The examination employs multiple-choice and scenario-
based questions that evaluate both theoretical comprehension and practical
decision-making ability. Success requires application of real-world knowledge to
solve installation, maintenance, and compliance challenges encountered in
professional practice. This assessment emphasizes critical thinking and adherence to
established standards governing mechanical work in Louisiana.
SECTION ONE: QUESTIONS 1–50
,1. Which component in a vapor-compression refrigeration system is responsible
for raising the pressure and temperature of refrigerant vapor?
A. Evaporator
B. Compressor
C. Condenser
D. Expansion valve
🟢 Correct Answer: B. Compressor
🔴 Rationale: The compressor draws low-pressure vapor from the evaporator and
compresses it into high-pressure, high-temperature vapor for delivery to the
condenser, enabling heat rejection.
2. A technician measures a suction line temperature of 55°F and a saturation
temperature of 40°F. What is the system superheat?
A. 15°F
B. 40°F
C. 55°F
D. 95°F
🟢 Correct Answer: A. 15°F
🔴 Rationale: Superheat is calculated by subtracting the saturation temperature
from the actual vapor line temperature. 55°F minus 40°F equals 15°F of superheat.
3. What is the primary purpose of a thermostatic expansion valve in an air
conditioning system?
A. To compress refrigerant vapor
B. To regulate refrigerant flow based on superheat
C. To reject heat to the outdoor air
D. To store excess liquid refrigerant
,🟢 Correct Answer: B. To regulate refrigerant flow based on superheat
🔴 Rationale: The TXV modulates refrigerant flow into the evaporator to maintain
a specific superheat setpoint, ensuring optimal coil performance and preventing
liquid floodback.
4. A residential HVAC system is short cycling during mild weather. Which of the
following is the most likely cause?
A. Low refrigerant charge
B. Oversized equipment
C. Dirty evaporator coil
D. Restricted liquid line filter drier
🟢 Correct Answer: B. Oversized equipment
🔴 Rationale: Oversized equipment satisfies the thermostat setpoint too quickly,
causing frequent cycling during periods of low load. Correct sizing using Manual J
prevents this condition.
5. According to the Louisiana Mechanical Code, which refrigerant classification
is permitted for high-probability systems used for human comfort?
A. Group B1 only
B. Group A1 or A2L
C. Group B2 or B3
D. Any flammable refrigerant
🟢 Correct Answer: B. Group A1 or A2L
🔴 Rationale: The Louisiana Mechanical Code amendment permits Group A1 or
A2L refrigerants for high-probability human comfort systems, while prohibiting
Group B1, B2, and B3 refrigerants in such applications .
, 6. A technician is recovering refrigerant from a system containing 60 pounds of
R-410A. What is the required evacuation level using recovery equipment
certified after November 15, 1993?
A. 0 inches Hg vacuum
B. 4 inches Hg vacuum
C. 10 inches Hg vacuum
D. 15 inches Hg vacuum
🟢 Correct Answer: C. 10 inches Hg vacuum
🔴 Rationale: EPA Section 608 regulations require recovery equipment certified
after November 15, 1993 to achieve 10 inches of mercury vacuum for high-
pressure appliances containing less than 200 pounds of refrigerant .
7. What is the primary function of a condensate drain trap on an air
conditioning system?
A. To increase airflow through the evaporator
B. To prevent air from being drawn through the drain line
C. To filter contaminants from condensate water
D. To regulate refrigerant pressure
🟢 Correct Answer: B. To prevent air from being drawn through the drain line
🔴 Rationale: The trap creates a water seal that prevents unconditioned air from
being pulled through the drain pan and into the supply air stream, maintaining
system efficiency.
8. A gas furnace is installed in a confined space using indoor air for combustion.
What is the minimum required volume per 1,000 BTU/hr of total input?
A. 25 cubic feet
B. 50 cubic feet
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALE 2027 Q&A| INSTANT
DOWNLOAD PDF.– QUESTIONS AND ANSWERS | VERIFIED AND WELL DETAILED
ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
Refrigeration Cycle Fundamentals and Components
HVAC System Installation, Maintenance, and Repair
Ductwork Design, Installation, and Air Distribution
Fuel Gas Piping and Combustion Appliance Venting
Refrigerant Handling, Recovery, and Environmental Compliance
Mechanical Code Compliance and Regulatory Requirements
Electrical Systems for HVAC Equipment
Load Calculations and System Sizing
Safety Procedures and Professional Standards
Introduction
The Louisiana HVAC Contractor Examination assesses the knowledge and
competency required for licensure in the heating, air conditioning, ventilation, duct
work, and refrigeration trade. Candidates must demonstrate understanding of
mechanical codes, refrigerant handling regulations, system design principles, and
safe installation practices. The examination employs multiple-choice and scenario-
based questions that evaluate both theoretical comprehension and practical
decision-making ability. Success requires application of real-world knowledge to
solve installation, maintenance, and compliance challenges encountered in
professional practice. This assessment emphasizes critical thinking and adherence to
established standards governing mechanical work in Louisiana.
SECTION ONE: QUESTIONS 1–50
,1. Which component in a vapor-compression refrigeration system is responsible
for raising the pressure and temperature of refrigerant vapor?
A. Evaporator
B. Compressor
C. Condenser
D. Expansion valve
🟢 Correct Answer: B. Compressor
🔴 Rationale: The compressor draws low-pressure vapor from the evaporator and
compresses it into high-pressure, high-temperature vapor for delivery to the
condenser, enabling heat rejection.
2. A technician measures a suction line temperature of 55°F and a saturation
temperature of 40°F. What is the system superheat?
A. 15°F
B. 40°F
C. 55°F
D. 95°F
🟢 Correct Answer: A. 15°F
🔴 Rationale: Superheat is calculated by subtracting the saturation temperature
from the actual vapor line temperature. 55°F minus 40°F equals 15°F of superheat.
3. What is the primary purpose of a thermostatic expansion valve in an air
conditioning system?
A. To compress refrigerant vapor
B. To regulate refrigerant flow based on superheat
C. To reject heat to the outdoor air
D. To store excess liquid refrigerant
,🟢 Correct Answer: B. To regulate refrigerant flow based on superheat
🔴 Rationale: The TXV modulates refrigerant flow into the evaporator to maintain
a specific superheat setpoint, ensuring optimal coil performance and preventing
liquid floodback.
4. A residential HVAC system is short cycling during mild weather. Which of the
following is the most likely cause?
A. Low refrigerant charge
B. Oversized equipment
C. Dirty evaporator coil
D. Restricted liquid line filter drier
🟢 Correct Answer: B. Oversized equipment
🔴 Rationale: Oversized equipment satisfies the thermostat setpoint too quickly,
causing frequent cycling during periods of low load. Correct sizing using Manual J
prevents this condition.
5. According to the Louisiana Mechanical Code, which refrigerant classification
is permitted for high-probability systems used for human comfort?
A. Group B1 only
B. Group A1 or A2L
C. Group B2 or B3
D. Any flammable refrigerant
🟢 Correct Answer: B. Group A1 or A2L
🔴 Rationale: The Louisiana Mechanical Code amendment permits Group A1 or
A2L refrigerants for high-probability human comfort systems, while prohibiting
Group B1, B2, and B3 refrigerants in such applications .
, 6. A technician is recovering refrigerant from a system containing 60 pounds of
R-410A. What is the required evacuation level using recovery equipment
certified after November 15, 1993?
A. 0 inches Hg vacuum
B. 4 inches Hg vacuum
C. 10 inches Hg vacuum
D. 15 inches Hg vacuum
🟢 Correct Answer: C. 10 inches Hg vacuum
🔴 Rationale: EPA Section 608 regulations require recovery equipment certified
after November 15, 1993 to achieve 10 inches of mercury vacuum for high-
pressure appliances containing less than 200 pounds of refrigerant .
7. What is the primary function of a condensate drain trap on an air
conditioning system?
A. To increase airflow through the evaporator
B. To prevent air from being drawn through the drain line
C. To filter contaminants from condensate water
D. To regulate refrigerant pressure
🟢 Correct Answer: B. To prevent air from being drawn through the drain line
🔴 Rationale: The trap creates a water seal that prevents unconditioned air from
being pulled through the drain pan and into the supply air stream, maintaining
system efficiency.
8. A gas furnace is installed in a confined space using indoor air for combustion.
What is the minimum required volume per 1,000 BTU/hr of total input?
A. 25 cubic feet
B. 50 cubic feet
