Practice Questions And Correct Answers

FDNY Q01 Certificate of Qualification for Refrigerating System Operating Engineer Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of a refrigerating system?
• To generate electricity
• To cool and remove heat from a space
• To increase air pressure
• To heat a building
• To cool and remove heat from a space

Rationale: Refrigerating systems are designed to remove heat from a

controlled space, thereby lowering its temperature.

• Which of the following is the most common refrigerant used in

modern systems?

• Ammonia (NH3) 1 / 4

B. R-22

• R-134a
• Water
• R-134a

Rationale: R-134a is widely used in commercial refrigeration due to

its lower ozone depletion potential and efficiency.

• What is the function of the evaporator in a refrigeration cycle?
• To compress refrigerant
• To absorb heat from the space to be cooled
• To condense refrigerant
• To regulate pressure
• To absorb heat from the space to be cooled

Rationale: The evaporator allows the refrigerant to absorb heat from

the surroundings, which lowers the temperature of the space.

• Which component increases the pressure and temperature of the

refrigerant vapor?

• Condenser
• Evaporator
• Compressor
• Expansion valve
• Compressor

Rationale: The compressor raises both the pressure and temperature

of the refrigerant so it can release heat in the condenser. 2 / 4

• What is the purpose of the condenser?
• To absorb heat
• To release heat from the refrigerant to the surroundings
• To expand refrigerant
• To reduce pressure
• To release heat from the refrigerant to the surroundings

Rationale: The condenser cools the high-pressure refrigerant vapor,

turning it into liquid while releasing heat to the environment.

• What does a thermostatic expansion valve do?
• Controls the flow of refrigerant into the evaporator
• Compresses refrigerant
• Pumps water through the system
• Measures temperature only
• Controls the flow of refrigerant into the evaporator

Rationale: The thermostatic expansion valve regulates refrigerant

flow to maintain proper superheat at the evaporator outlet.

7. Superheat in a refrigeration system refers to:

• Refrigerant temperature above its boiling point
• Refrigerant pressure in the condenser
• Temperature of the cooling coil
• Heat removed from the space
• Refrigerant temperature above its boiling point 3 / 4

Rationale: Superheat is the temperature of vapor above its

saturation point, ensuring that no liquid enters the compressor.

8. Subcooling refers to:

• Refrigerant temperature below its condensation point
• Evaporator coil temperature
• Heat absorbed by the refrigerant
• Compressor discharge temperature
• Refrigerant temperature below its condensation point

Rationale: Subcooling ensures the refrigerant entering the expansion

device is fully liquid for efficient operation.

• Which refrigerant is classified as anhydrous ammonia?

A. R-22

B. R-717

• R-134a

D. R-404A

B. R-717

Rationale: R-717 is the chemical designation for ammonia, commonly

used in industrial refrigeration.

• What is the main hazard of ammonia-based refrigeration

systems?

• Toxicity and flammability
• Low efficiency
• High cost
• / 4