NYC Health + Hospitals Refrigeration
Engineer Examination Practice Exam
2026 | 100 Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. What is the primary purpose of a refrigeration compressor?
A. To remove moisture from the evaporator
B. To circulate refrigerant and raise its pressure and temperature
C. To reduce condenser pressure
D. To regulate airflow
Answer: To circulate refrigerant and raise its pressure and temperature
Rationale: The compressor draws low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature vapor for
delivery to the condenser.
2. Which component removes heat from the conditioned space in a
refrigeration system?
A. Condenser
B. Compressor
,C. Evaporator
D. Receiver
Answer: Evaporator
Rationale: The evaporator absorbs heat from the space, product, or process
being cooled as refrigerant changes from liquid to vapor.
3. What is the primary function of a condenser?
A. Absorb heat from the refrigerated space
B. Reject heat from the refrigerant to the surroundings
C. Increase refrigerant flow through the evaporator
D. Reduce suction pressure
Answer: Reject heat from the refrigerant to the surroundings
Rationale: The condenser removes heat from the high-pressure refrigerant
vapor and condenses it into a liquid.
4. What is the purpose of an expansion valve?
A. Increase compressor speed
B. Raise refrigerant pressure
C. Meter refrigerant into the evaporator and reduce its pressure
D. Remove non-condensable gases
Answer: Meter refrigerant into the evaporator and reduce its pressure
Rationale: The expansion valve controls refrigerant flow while producing the
pressure drop required for evaporation at a lower temperature.
5. What does superheat represent?
A. Heat contained in liquid refrigerant below saturation
B. Temperature of vapor above its saturation temperature
C. Temperature difference between condenser and ambient
D. Pressure difference between discharge and suction
,Answer: Temperature of vapor above its saturation temperature
Rationale: Superheat is the difference between actual vapor temperature and
the saturation temperature at the corresponding pressure.
6. What does subcooling indicate?
A. Liquid temperature below its saturation temperature
B. Vapor temperature above saturation
C. Compressor overheating
D. Evaporator flooding
Answer: Liquid temperature below its saturation temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled below its
condensing saturation temperature, helping ensure solid liquid reaches the
metering device.
7. Which condition can result from excessive refrigerant charge?
A. Low head pressure
B. High condenser pressure
C. Extremely low suction pressure only
D. Loss of compressor lubrication immediately
Answer: High condenser pressure
Rationale: An overcharged system can contain excessive liquid refrigerant in the
condenser and receiver, reducing available condensing area and increasing head
pressure.
8. What is a common cause of low suction pressure?
A. Excessive evaporator airflow
B. Restricted refrigerant flow
C. Excessive refrigerant charge
D. High indoor load
, Answer: Restricted refrigerant flow
Rationale: A restricted filter-drier, metering device, or liquid line can starve the
evaporator and cause low suction pressure.
9. What is the purpose of a filter-drier?
A. Increase compressor capacity
B. Remove moisture and contaminants from refrigerant
C. Raise evaporator temperature
D. Control condenser fans
Answer: Remove moisture and contaminants from refrigerant
Rationale: Filter-driers protect the refrigeration system by trapping debris and
absorbing moisture that can cause corrosion, ice formation, and chemical
reactions.
10.Why is moisture dangerous in a refrigeration system?
A. It increases airflow
B. It can freeze at the expansion device and form acids
C. It improves compressor efficiency
D. It increases evaporator capacity
Answer: It can freeze at the expansion device and form acids
Rationale: Moisture can freeze at restrictions and may react with refrigerant or
oil to produce corrosive compounds.
11.What instrument is commonly used to measure refrigerant pressure?
A. Hygrometer
B. Manifold gauge set
C. Megohmmeter
D. Tachometer
Answer: Manifold gauge set
Engineer Examination Practice Exam
2026 | 100 Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. What is the primary purpose of a refrigeration compressor?
A. To remove moisture from the evaporator
B. To circulate refrigerant and raise its pressure and temperature
C. To reduce condenser pressure
D. To regulate airflow
Answer: To circulate refrigerant and raise its pressure and temperature
Rationale: The compressor draws low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature vapor for
delivery to the condenser.
2. Which component removes heat from the conditioned space in a
refrigeration system?
A. Condenser
B. Compressor
,C. Evaporator
D. Receiver
Answer: Evaporator
Rationale: The evaporator absorbs heat from the space, product, or process
being cooled as refrigerant changes from liquid to vapor.
3. What is the primary function of a condenser?
A. Absorb heat from the refrigerated space
B. Reject heat from the refrigerant to the surroundings
C. Increase refrigerant flow through the evaporator
D. Reduce suction pressure
Answer: Reject heat from the refrigerant to the surroundings
Rationale: The condenser removes heat from the high-pressure refrigerant
vapor and condenses it into a liquid.
4. What is the purpose of an expansion valve?
A. Increase compressor speed
B. Raise refrigerant pressure
C. Meter refrigerant into the evaporator and reduce its pressure
D. Remove non-condensable gases
Answer: Meter refrigerant into the evaporator and reduce its pressure
Rationale: The expansion valve controls refrigerant flow while producing the
pressure drop required for evaporation at a lower temperature.
5. What does superheat represent?
A. Heat contained in liquid refrigerant below saturation
B. Temperature of vapor above its saturation temperature
C. Temperature difference between condenser and ambient
D. Pressure difference between discharge and suction
,Answer: Temperature of vapor above its saturation temperature
Rationale: Superheat is the difference between actual vapor temperature and
the saturation temperature at the corresponding pressure.
6. What does subcooling indicate?
A. Liquid temperature below its saturation temperature
B. Vapor temperature above saturation
C. Compressor overheating
D. Evaporator flooding
Answer: Liquid temperature below its saturation temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled below its
condensing saturation temperature, helping ensure solid liquid reaches the
metering device.
7. Which condition can result from excessive refrigerant charge?
A. Low head pressure
B. High condenser pressure
C. Extremely low suction pressure only
D. Loss of compressor lubrication immediately
Answer: High condenser pressure
Rationale: An overcharged system can contain excessive liquid refrigerant in the
condenser and receiver, reducing available condensing area and increasing head
pressure.
8. What is a common cause of low suction pressure?
A. Excessive evaporator airflow
B. Restricted refrigerant flow
C. Excessive refrigerant charge
D. High indoor load
, Answer: Restricted refrigerant flow
Rationale: A restricted filter-drier, metering device, or liquid line can starve the
evaporator and cause low suction pressure.
9. What is the purpose of a filter-drier?
A. Increase compressor capacity
B. Remove moisture and contaminants from refrigerant
C. Raise evaporator temperature
D. Control condenser fans
Answer: Remove moisture and contaminants from refrigerant
Rationale: Filter-driers protect the refrigeration system by trapping debris and
absorbing moisture that can cause corrosion, ice formation, and chemical
reactions.
10.Why is moisture dangerous in a refrigeration system?
A. It increases airflow
B. It can freeze at the expansion device and form acids
C. It improves compressor efficiency
D. It increases evaporator capacity
Answer: It can freeze at the expansion device and form acids
Rationale: Moisture can freeze at restrictions and may react with refrigerant or
oil to produce corrosive compounds.
11.What instrument is commonly used to measure refrigerant pressure?
A. Hygrometer
B. Manifold gauge set
C. Megohmmeter
D. Tachometer
Answer: Manifold gauge set
