Ontario Refrigeration Operator Class B Exam (TSSA) 2027
(Technical Standards and Safety Authority Technical Standards and
Safety Authority)
1. What is the primary purpose of a refrigeration system?
A. To generate heat
B. To remove heat from a space
C. To compress air
D. To increase humidity
Answer: B
Rationale: Refrigeration systems are designed to transfer heat
from one area to another, effectively removing heat from a
controlled space.
2. Which refrigerant property is most important for safety in
occupied spaces?
A. High toxicity
B. Low boiling point
C. Low toxicity
D. High pressure
Answer: C
, Rationale: Refrigerants used in occupied spaces must have low
toxicity to reduce health risks in case of leaks.
3. What is the function of the compressor in a refrigeration system?
A. To absorb heat
B. To expand refrigerant
C. To circulate refrigerant and raise pressure
D. To store refrigerant
Answer: C
Rationale: The compressor circulates refrigerant through the
system and increases its pressure and temperature.
4. What happens to refrigerant in the evaporator?
A. It condenses and releases heat
B. It absorbs heat and evaporates
C. It is compressed
D. It is filtered
Answer: B
Rationale: In the evaporator, refrigerant absorbs heat from the
environment and changes from liquid to vapor.
,5. Which component removes heat from the refrigerant to the
outside air?
A. Compressor
B. Expansion valve
C. Condenser
D. Evaporator
Answer: C
Rationale: The condenser releases heat from the refrigerant to the
surrounding environment.
6. What is the role of the expansion valve?
A. Compress refrigerant
B. Increase refrigerant temperature
C. Reduce refrigerant pressure
D. Store refrigerant
Answer: C
Rationale: The expansion valve reduces pressure, allowing
refrigerant to cool before entering the evaporator.
7. Which refrigerant state has the highest pressure in the system?
A. Low-pressure vapor
, B. High-pressure liquid
C. Low-pressure liquid
D. Superheated vapor at evaporator outlet
Answer: B
Rationale: After compression and condensation, refrigerant exists
as a high-pressure liquid.
8. What is superheat?
A. Liquid refrigerant below freezing
B. Vapor heated above saturation temperature
C. Heat added to condenser
D. Pressure drop in system
Answer: B
Rationale: Superheat refers to vapor that has been heated above
its boiling point after complete evaporation.
9. What is subcooling?
A. Cooling vapor below saturation
B. Cooling liquid below its condensing temperature
C. Heating refrigerant gas
D. Compressing liquid refrigerant
(Technical Standards and Safety Authority Technical Standards and
Safety Authority)
1. What is the primary purpose of a refrigeration system?
A. To generate heat
B. To remove heat from a space
C. To compress air
D. To increase humidity
Answer: B
Rationale: Refrigeration systems are designed to transfer heat
from one area to another, effectively removing heat from a
controlled space.
2. Which refrigerant property is most important for safety in
occupied spaces?
A. High toxicity
B. Low boiling point
C. Low toxicity
D. High pressure
Answer: C
, Rationale: Refrigerants used in occupied spaces must have low
toxicity to reduce health risks in case of leaks.
3. What is the function of the compressor in a refrigeration system?
A. To absorb heat
B. To expand refrigerant
C. To circulate refrigerant and raise pressure
D. To store refrigerant
Answer: C
Rationale: The compressor circulates refrigerant through the
system and increases its pressure and temperature.
4. What happens to refrigerant in the evaporator?
A. It condenses and releases heat
B. It absorbs heat and evaporates
C. It is compressed
D. It is filtered
Answer: B
Rationale: In the evaporator, refrigerant absorbs heat from the
environment and changes from liquid to vapor.
,5. Which component removes heat from the refrigerant to the
outside air?
A. Compressor
B. Expansion valve
C. Condenser
D. Evaporator
Answer: C
Rationale: The condenser releases heat from the refrigerant to the
surrounding environment.
6. What is the role of the expansion valve?
A. Compress refrigerant
B. Increase refrigerant temperature
C. Reduce refrigerant pressure
D. Store refrigerant
Answer: C
Rationale: The expansion valve reduces pressure, allowing
refrigerant to cool before entering the evaporator.
7. Which refrigerant state has the highest pressure in the system?
A. Low-pressure vapor
, B. High-pressure liquid
C. Low-pressure liquid
D. Superheated vapor at evaporator outlet
Answer: B
Rationale: After compression and condensation, refrigerant exists
as a high-pressure liquid.
8. What is superheat?
A. Liquid refrigerant below freezing
B. Vapor heated above saturation temperature
C. Heat added to condenser
D. Pressure drop in system
Answer: B
Rationale: Superheat refers to vapor that has been heated above
its boiling point after complete evaporation.
9. What is subcooling?
A. Cooling vapor below saturation
B. Cooling liquid below its condensing temperature
C. Heating refrigerant gas
D. Compressing liquid refrigerant
