Delaware Refrigeration Contractor
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary function of a refrigeration system?
A. Increase air pressure
B. Transfer heat from a low-temperature area to a high-temperature area
C. Generate cold air
D. Eliminate humidity completely
Correct Answer: B
Rationale: The fundamental purpose of a refrigeration system is not to
create cold but to remove heat from a controlled space and reject it
elsewhere. This heat transfer process follows thermodynamic principles
using refrigerant circulation.
2. Which component starts the refrigeration cycle?
A. Condenser
B. Expansion valve
C. Compressor
D. Evaporator
Correct Answer: C
Rationale: The compressor is considered the heart of the system because it
circulates refrigerant by raising its pressure and temperature, initiating
the refrigeration cycle.
3. What happens to refrigerant pressure in the condenser?
A. It decreases
B. It remains constant
C. It increases sharply
, D. It is converted to vacuum
Correct Answer: A
Rationale: In the condenser, high-pressure vapor rejects heat and changes
into a liquid, resulting in a drop in pressure while maintaining high
pressure relative to the evaporator side.
4. Which refrigerant condition enters the evaporator?
A. High-pressure liquid
B. Low-pressure liquid
C. High-pressure vapor
D. Low-pressure mixture
Correct Answer: D
Rationale: The evaporator receives a low-pressure mixture of liquid and
vapor after expansion, allowing it to absorb heat efficiently from the
conditioned space.
5. What is the purpose of the expansion valve?
A. Compress refrigerant
B. Increase refrigerant temperature
C. Meter refrigerant flow and reduce pressure
D. Store refrigerant
Correct Answer: C
Rationale: The expansion device controls refrigerant flow into the
evaporator and reduces pressure, allowing rapid cooling and phase
change.
6. What is superheat?
A. Liquid refrigerant below boiling point
B. Temperature below saturation
C. Vapor refrigerant heated above boiling point
D. Pressure above normal range
Correct Answer: C
Rationale: Superheat refers to vapor refrigerant heated beyond its boiling
, point after complete evaporation, ensuring no liquid enters the
compressor.
7. What is subcooling?
A. Cooling vapor below saturation
B. Cooling liquid below its condensing temperature
C. Increasing pressure in evaporator
D. Heating refrigerant gas
Correct Answer: B
Rationale: Subcooling is the process of cooling liquid refrigerant below its
condensation temperature to ensure efficient expansion and prevent flash
gas formation.
8. Which refrigerant safety classification indicates higher toxicity and
flammability risk?
A. A1
B. B2
C. A3
D. A2L
Correct Answer: C
Rationale: A3 refrigerants are highly flammable with low toxicity,
requiring strict handling and safety measures under modern HVAC codes.
9. What tool is used to measure system pressures?
A. Thermometer
B. Manifold gauge set
C. Anemometer
D. Psychrometer
Correct Answer: B
Rationale: A manifold gauge set measures both high and low side
pressures, essential for diagnosing refrigeration system performance.
10.What is the purpose of a receiver in a refrigeration system?
A. Compress refrigerant
B. Store liquid refrigerant
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary function of a refrigeration system?
A. Increase air pressure
B. Transfer heat from a low-temperature area to a high-temperature area
C. Generate cold air
D. Eliminate humidity completely
Correct Answer: B
Rationale: The fundamental purpose of a refrigeration system is not to
create cold but to remove heat from a controlled space and reject it
elsewhere. This heat transfer process follows thermodynamic principles
using refrigerant circulation.
2. Which component starts the refrigeration cycle?
A. Condenser
B. Expansion valve
C. Compressor
D. Evaporator
Correct Answer: C
Rationale: The compressor is considered the heart of the system because it
circulates refrigerant by raising its pressure and temperature, initiating
the refrigeration cycle.
3. What happens to refrigerant pressure in the condenser?
A. It decreases
B. It remains constant
C. It increases sharply
, D. It is converted to vacuum
Correct Answer: A
Rationale: In the condenser, high-pressure vapor rejects heat and changes
into a liquid, resulting in a drop in pressure while maintaining high
pressure relative to the evaporator side.
4. Which refrigerant condition enters the evaporator?
A. High-pressure liquid
B. Low-pressure liquid
C. High-pressure vapor
D. Low-pressure mixture
Correct Answer: D
Rationale: The evaporator receives a low-pressure mixture of liquid and
vapor after expansion, allowing it to absorb heat efficiently from the
conditioned space.
5. What is the purpose of the expansion valve?
A. Compress refrigerant
B. Increase refrigerant temperature
C. Meter refrigerant flow and reduce pressure
D. Store refrigerant
Correct Answer: C
Rationale: The expansion device controls refrigerant flow into the
evaporator and reduces pressure, allowing rapid cooling and phase
change.
6. What is superheat?
A. Liquid refrigerant below boiling point
B. Temperature below saturation
C. Vapor refrigerant heated above boiling point
D. Pressure above normal range
Correct Answer: C
Rationale: Superheat refers to vapor refrigerant heated beyond its boiling
, point after complete evaporation, ensuring no liquid enters the
compressor.
7. What is subcooling?
A. Cooling vapor below saturation
B. Cooling liquid below its condensing temperature
C. Increasing pressure in evaporator
D. Heating refrigerant gas
Correct Answer: B
Rationale: Subcooling is the process of cooling liquid refrigerant below its
condensation temperature to ensure efficient expansion and prevent flash
gas formation.
8. Which refrigerant safety classification indicates higher toxicity and
flammability risk?
A. A1
B. B2
C. A3
D. A2L
Correct Answer: C
Rationale: A3 refrigerants are highly flammable with low toxicity,
requiring strict handling and safety measures under modern HVAC codes.
9. What tool is used to measure system pressures?
A. Thermometer
B. Manifold gauge set
C. Anemometer
D. Psychrometer
Correct Answer: B
Rationale: A manifold gauge set measures both high and low side
pressures, essential for diagnosing refrigeration system performance.
10.What is the purpose of a receiver in a refrigeration system?
A. Compress refrigerant
B. Store liquid refrigerant
