CHILLER OPERATOR CERTIFICATION EXAM NEWEST
ACTUAL EXAM COMPLETE 100 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+||BRAND NEW
VERSION!!
1. What is the primary function of a chiller in an HVAC system?
A. Increase indoor humidity
✓B. Remove heat from a liquid
C. Produce steam for heating
D. Filter air
Rationale: The main function of a chiller is to remove heat from water or another
liquid to provide cooling for the building.
2. Which type of chiller uses a refrigerant to absorb heat directly from water or
process fluid?
✓A. Vapor-compression chiller
B. Absorption chiller
C. Evaporative chiller
D. Centrifugal chiller
Rationale: Vapor-compression chillers use refrigerant to absorb heat and transfer
it to the condenser.
3. What component of a chiller compresses the refrigerant vapor to a high
pressure?
A. Evaporator
B. Expansion valve
✓C. Compressor
D. Condenser
Rationale: The compressor increases the pressure of the refrigerant vapor to
prepare it for condensation.
,4. In a centrifugal chiller, what is the role of the impeller?
✓A. Increase the velocity of refrigerant
B. Reduce refrigerant temperature
C. Control refrigerant expansion
D. Pump chilled water
Rationale: The impeller in a centrifugal chiller accelerates the refrigerant vapor,
which is then converted into pressure energy.
5. What is the function of the expansion valve in a chiller?
A. Increase refrigerant pressure
B. Compress refrigerant
✓C. Reduce refrigerant pressure and temperature
D. Heat the refrigerant
Rationale: The expansion valve reduces the pressure of the refrigerant, which
lowers its temperature before entering the evaporator.
6. Which type of chiller typically uses lithium bromide as a working fluid?
A. Vapor-compression chiller
✓B. Absorption chiller
C. Centrifugal chiller
D. Scroll chiller
Rationale: Absorption chillers often use a lithium bromide solution as the
absorbent to remove heat.
7. What is the common cause of high head pressure in a chiller system?
A. Low refrigerant charge
B. Evaporator fouling
✓C. Condenser fouling
D. Expansion valve malfunction
Rationale: Fouled condensers reduce heat rejection, increasing the head pressure.
8. Which type of maintenance is most important to prevent fouling in
evaporator and condenser tubes?
A. Electrical inspection
, ✓B. Water treatment
C. Oil change
D. Insulation check
Rationale: Proper water treatment prevents scale, corrosion, and biological
growth that can foul heat exchanger tubes.
9. What does the term “chilled water ΔT” refer to?
A. Difference between outdoor and indoor temperature
B. Difference between supply and outdoor air temperature
✓C. Temperature difference between chilled water supply and return
D. Temperature drop across the condenser
Rationale: ΔT measures the difference in temperature between the water leaving
the chiller and returning to it, indicating system efficiency.
10. Which of the following can indicate refrigerant leakage in a chiller system?
A. Low condenser pressure
B. High chilled water flow
✓C. Low suction pressure
D. High evaporator temperature
Rationale: Low suction pressure often indicates a refrigerant leak or insufficient
charge.
11. What is the main purpose of a chiller’s condenser?
A. Absorb heat from the process
B. Reduce water flow
✓C. Reject heat from the refrigerant to the environment
D. Increase refrigerant suction pressure
Rationale: The condenser transfers heat from the high-pressure refrigerant to a
cooling medium (air or water).
12. In a screw chiller, what is the main characteristic of the compressor?
A. Uses centrifugal force to move refrigerant
B. Is reciprocating in design
✓C. Uses male and female rotors to compress refrigerant
ACTUAL EXAM COMPLETE 100 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+||BRAND NEW
VERSION!!
1. What is the primary function of a chiller in an HVAC system?
A. Increase indoor humidity
✓B. Remove heat from a liquid
C. Produce steam for heating
D. Filter air
Rationale: The main function of a chiller is to remove heat from water or another
liquid to provide cooling for the building.
2. Which type of chiller uses a refrigerant to absorb heat directly from water or
process fluid?
✓A. Vapor-compression chiller
B. Absorption chiller
C. Evaporative chiller
D. Centrifugal chiller
Rationale: Vapor-compression chillers use refrigerant to absorb heat and transfer
it to the condenser.
3. What component of a chiller compresses the refrigerant vapor to a high
pressure?
A. Evaporator
B. Expansion valve
✓C. Compressor
D. Condenser
Rationale: The compressor increases the pressure of the refrigerant vapor to
prepare it for condensation.
,4. In a centrifugal chiller, what is the role of the impeller?
✓A. Increase the velocity of refrigerant
B. Reduce refrigerant temperature
C. Control refrigerant expansion
D. Pump chilled water
Rationale: The impeller in a centrifugal chiller accelerates the refrigerant vapor,
which is then converted into pressure energy.
5. What is the function of the expansion valve in a chiller?
A. Increase refrigerant pressure
B. Compress refrigerant
✓C. Reduce refrigerant pressure and temperature
D. Heat the refrigerant
Rationale: The expansion valve reduces the pressure of the refrigerant, which
lowers its temperature before entering the evaporator.
6. Which type of chiller typically uses lithium bromide as a working fluid?
A. Vapor-compression chiller
✓B. Absorption chiller
C. Centrifugal chiller
D. Scroll chiller
Rationale: Absorption chillers often use a lithium bromide solution as the
absorbent to remove heat.
7. What is the common cause of high head pressure in a chiller system?
A. Low refrigerant charge
B. Evaporator fouling
✓C. Condenser fouling
D. Expansion valve malfunction
Rationale: Fouled condensers reduce heat rejection, increasing the head pressure.
8. Which type of maintenance is most important to prevent fouling in
evaporator and condenser tubes?
A. Electrical inspection
, ✓B. Water treatment
C. Oil change
D. Insulation check
Rationale: Proper water treatment prevents scale, corrosion, and biological
growth that can foul heat exchanger tubes.
9. What does the term “chilled water ΔT” refer to?
A. Difference between outdoor and indoor temperature
B. Difference between supply and outdoor air temperature
✓C. Temperature difference between chilled water supply and return
D. Temperature drop across the condenser
Rationale: ΔT measures the difference in temperature between the water leaving
the chiller and returning to it, indicating system efficiency.
10. Which of the following can indicate refrigerant leakage in a chiller system?
A. Low condenser pressure
B. High chilled water flow
✓C. Low suction pressure
D. High evaporator temperature
Rationale: Low suction pressure often indicates a refrigerant leak or insufficient
charge.
11. What is the main purpose of a chiller’s condenser?
A. Absorb heat from the process
B. Reduce water flow
✓C. Reject heat from the refrigerant to the environment
D. Increase refrigerant suction pressure
Rationale: The condenser transfers heat from the high-pressure refrigerant to a
cooling medium (air or water).
12. In a screw chiller, what is the main characteristic of the compressor?
A. Uses centrifugal force to move refrigerant
B. Is reciprocating in design
✓C. Uses male and female rotors to compress refrigerant
