Kentucky HVAC Master Contractor Exam
Newest 2025-2026 Update Questions
Fast Reviwed From Actual Exams 100
Questions And 100% Verified Answers
With Convenient Explanations Grade A+
Q&A | Instant Download Pdf
1. A residential system has excessive humidity during cooling operation. Which
condition is MOST likely the cause?
A. Oversized condenser fan
B. Oversized cooling equipment
C. Low refrigerant charge
D. Excessive duct insulation
Answer: B
Rationale: Oversized equipment short cycles, reducing latent heat removal
and increasing indoor humidity.
2. What is the primary purpose of a thermostat in an HVAC system?
A. Measure refrigerant pressure
B. Control electrical resistance
C. Maintain set temperature by cycling equipment
D. Regulate airflow velocity
Answer: C
Rationale: A thermostat maintains desired temperature by controlling
system operation cycles.
3. Which refrigerant is commonly used in modern residential air conditioning
systems?
, A. R-22
B. R-410A
C. Ammonia
D. R-12
Answer: B
Rationale: R-410A is widely used in newer systems due to environmental
regulations.
4. What tool is used to measure superheat in a refrigeration system?
A. Psychrometer
B. Manifold gauge set
C. Clamp ammeter
D. Infrared thermometer
Answer: B
Rationale: Manifold gauges are used to measure pressures needed for
superheat calculation.
5. Which component removes moisture from refrigerant vapor leaving the
evaporator?
A. Compressor
B. Condenser
C. Expansion valve
D. Evaporator coil
Answer: B
Rationale: The condenser rejects heat and begins refrigerant
condensation.
6. A split system short cycles frequently. Which is a likely cause?
A. Dirty air filter
B. Oversized system
C. Low voltage supply
D. High refrigerant subcooling
Answer: B
, Rationale: Oversized systems reach set temperature too quickly, causing
short cycling.
7. What is the function of a metering device?
A. Increase refrigerant pressure
B. Control refrigerant flow into evaporator
C. Remove heat from air
D. Compress refrigerant gas
Answer: B
Rationale: Metering devices regulate refrigerant flow into the evaporator.
8. Which code governs mechanical systems in most Kentucky jurisdictions?
A. NEC
B. IMC
C. NFPA 70B
D. OSHA 1926
Answer: B
Rationale: The International Mechanical Code is widely adopted for HVAC
systems.
9. What happens when airflow over an evaporator coil is reduced?
A. Superheat decreases
B. Coil temperature rises
C. Refrigerant pressure increases
D. Compressor amps decrease significantly
Answer: B
Rationale: Reduced airflow causes less heat absorption, raising coil
temperature.
10.Which gas is commonly used for leak detection in HVAC systems?
A. Oxygen
B. Nitrogen
C. Carbon monoxide
D. Argon
Newest 2025-2026 Update Questions
Fast Reviwed From Actual Exams 100
Questions And 100% Verified Answers
With Convenient Explanations Grade A+
Q&A | Instant Download Pdf
1. A residential system has excessive humidity during cooling operation. Which
condition is MOST likely the cause?
A. Oversized condenser fan
B. Oversized cooling equipment
C. Low refrigerant charge
D. Excessive duct insulation
Answer: B
Rationale: Oversized equipment short cycles, reducing latent heat removal
and increasing indoor humidity.
2. What is the primary purpose of a thermostat in an HVAC system?
A. Measure refrigerant pressure
B. Control electrical resistance
C. Maintain set temperature by cycling equipment
D. Regulate airflow velocity
Answer: C
Rationale: A thermostat maintains desired temperature by controlling
system operation cycles.
3. Which refrigerant is commonly used in modern residential air conditioning
systems?
, A. R-22
B. R-410A
C. Ammonia
D. R-12
Answer: B
Rationale: R-410A is widely used in newer systems due to environmental
regulations.
4. What tool is used to measure superheat in a refrigeration system?
A. Psychrometer
B. Manifold gauge set
C. Clamp ammeter
D. Infrared thermometer
Answer: B
Rationale: Manifold gauges are used to measure pressures needed for
superheat calculation.
5. Which component removes moisture from refrigerant vapor leaving the
evaporator?
A. Compressor
B. Condenser
C. Expansion valve
D. Evaporator coil
Answer: B
Rationale: The condenser rejects heat and begins refrigerant
condensation.
6. A split system short cycles frequently. Which is a likely cause?
A. Dirty air filter
B. Oversized system
C. Low voltage supply
D. High refrigerant subcooling
Answer: B
, Rationale: Oversized systems reach set temperature too quickly, causing
short cycling.
7. What is the function of a metering device?
A. Increase refrigerant pressure
B. Control refrigerant flow into evaporator
C. Remove heat from air
D. Compress refrigerant gas
Answer: B
Rationale: Metering devices regulate refrigerant flow into the evaporator.
8. Which code governs mechanical systems in most Kentucky jurisdictions?
A. NEC
B. IMC
C. NFPA 70B
D. OSHA 1926
Answer: B
Rationale: The International Mechanical Code is widely adopted for HVAC
systems.
9. What happens when airflow over an evaporator coil is reduced?
A. Superheat decreases
B. Coil temperature rises
C. Refrigerant pressure increases
D. Compressor amps decrease significantly
Answer: B
Rationale: Reduced airflow causes less heat absorption, raising coil
temperature.
10.Which gas is commonly used for leak detection in HVAC systems?
A. Oxygen
B. Nitrogen
C. Carbon monoxide
D. Argon
