Ontario Refrigeration Operator Class B Exam (TSSA)
Questions And Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. Describe the changes that occur to the refrigerant as it passes through the
expansion valve.
The refrigerant experiences a drop in pressure and temperature,
transitioning to a low-pressure liquid state.
The refrigerant increases in pressure and temperature, becoming a
high-pressure gas.
The refrigerant remains in a gaseous state with no change in pressure.
The refrigerant condenses into a solid form due to temperature
decrease.
2. In a scenario where electrical power is limited, which refrigeration system
would be more suitable for a remote location, and why?
Both systems are equally suitable regardless of power availability.
Absorption system, because it operates solely on electrical power.
Compression system, because it is more efficient in cooling.
Absorption system, because it requires less electrical power and
can utilize alternative heat sources.
3. The state of the refrigerant as it enters and exits a condenser is as follows:
High pressure gas in, high pressure liquid out
Low temperature liquid in, higher pressure gas out
High pressure gas in, low pressure liquid out
Superheated gas in, high temperature liquid out
,4. What type of refrigeration system is commonly associated with lithium
bromide?
Thermoelectric systems
Absorption refrigeration systems
Vapor-compression systems
Mechanical refrigeration systems
5. Dry bulb temperature is:
The heat required to raise the temperature of unit mass of gas and its
accompanying vapor one degree at constant pressure
None of the above
The steady state temperature reached by a small amount of liquid
evaporating in to a large amount of unsaturated vapor gas mixture
The temperature of vapor free gas mixture as ordinarily determined
by immersion of thermometer in a mixture
6. ____ is commonly used as the refrigerant in a lithium bromide absorption
system
Freon
Air
Water
Carbon dioxide
Ammonia
7. How would Dalton's law of partial pressures affect the design of a
refrigeration system using a mixture of refrigerants?
, The design must account for the combined pressures of the
refrigerant mixture to ensure optimal performance and efficiency.
The design should ignore the individual pressures of the gases to
simplify calculations.
The system should only use one type of refrigerant to avoid
complications.
The design can operate effectively without considering temperature
variations.
8. Relative humidity is
Not the same for different temperatures
Not affected when air is passed over a cooling coil
The percentage of moisture in the air compared to the amount it
could hold at the same pressure and temperature
A point where air will not hold any more moisture than 60%
9. Describe the role of water in lithium bromide absorption systems and how it
contributes to the refrigeration cycle.
Water acts as the refrigerant that absorbs heat during the
evaporation process, facilitating cooling.
Water is the primary energy source for the compressor in the system.
Water is used to increase humidity in the system.
Water is used as a coolant in the condenser only, not in the
evaporation process.
10. Describe the main difference in energy consumption between compression
and absorption refrigeration systems.
, Compression systems generally require more electrical power than
absorption systems, which utilize heat energy.
Compression systems use heat energy, while absorption systems use
electrical power.
Both systems consume equal amounts of electrical power.
Absorption systems require more electrical power due to their
reliance on heat.
11. In an ammonia absorption system, where is cooling water circulated?
1. the generator
2. the absorber
3. the evaporator
4. the condenser
1, 2
3, 4
1, 3
2, 4
1, 4
12. In a lithium bromide absorption system, if the water supply is compromised,
what would be the immediate effect on the system's performance?
The compressor would work harder to compensate for the lack of
water.
The system would switch to a different refrigerant automatically.
The system would operate more efficiently due to less water usage.
The cooling efficiency would decrease significantly due to
inadequate heat absorption.
Questions And Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. Describe the changes that occur to the refrigerant as it passes through the
expansion valve.
The refrigerant experiences a drop in pressure and temperature,
transitioning to a low-pressure liquid state.
The refrigerant increases in pressure and temperature, becoming a
high-pressure gas.
The refrigerant remains in a gaseous state with no change in pressure.
The refrigerant condenses into a solid form due to temperature
decrease.
2. In a scenario where electrical power is limited, which refrigeration system
would be more suitable for a remote location, and why?
Both systems are equally suitable regardless of power availability.
Absorption system, because it operates solely on electrical power.
Compression system, because it is more efficient in cooling.
Absorption system, because it requires less electrical power and
can utilize alternative heat sources.
3. The state of the refrigerant as it enters and exits a condenser is as follows:
High pressure gas in, high pressure liquid out
Low temperature liquid in, higher pressure gas out
High pressure gas in, low pressure liquid out
Superheated gas in, high temperature liquid out
,4. What type of refrigeration system is commonly associated with lithium
bromide?
Thermoelectric systems
Absorption refrigeration systems
Vapor-compression systems
Mechanical refrigeration systems
5. Dry bulb temperature is:
The heat required to raise the temperature of unit mass of gas and its
accompanying vapor one degree at constant pressure
None of the above
The steady state temperature reached by a small amount of liquid
evaporating in to a large amount of unsaturated vapor gas mixture
The temperature of vapor free gas mixture as ordinarily determined
by immersion of thermometer in a mixture
6. ____ is commonly used as the refrigerant in a lithium bromide absorption
system
Freon
Air
Water
Carbon dioxide
Ammonia
7. How would Dalton's law of partial pressures affect the design of a
refrigeration system using a mixture of refrigerants?
, The design must account for the combined pressures of the
refrigerant mixture to ensure optimal performance and efficiency.
The design should ignore the individual pressures of the gases to
simplify calculations.
The system should only use one type of refrigerant to avoid
complications.
The design can operate effectively without considering temperature
variations.
8. Relative humidity is
Not the same for different temperatures
Not affected when air is passed over a cooling coil
The percentage of moisture in the air compared to the amount it
could hold at the same pressure and temperature
A point where air will not hold any more moisture than 60%
9. Describe the role of water in lithium bromide absorption systems and how it
contributes to the refrigeration cycle.
Water acts as the refrigerant that absorbs heat during the
evaporation process, facilitating cooling.
Water is the primary energy source for the compressor in the system.
Water is used to increase humidity in the system.
Water is used as a coolant in the condenser only, not in the
evaporation process.
10. Describe the main difference in energy consumption between compression
and absorption refrigeration systems.
, Compression systems generally require more electrical power than
absorption systems, which utilize heat energy.
Compression systems use heat energy, while absorption systems use
electrical power.
Both systems consume equal amounts of electrical power.
Absorption systems require more electrical power due to their
reliance on heat.
11. In an ammonia absorption system, where is cooling water circulated?
1. the generator
2. the absorber
3. the evaporator
4. the condenser
1, 2
3, 4
1, 3
2, 4
1, 4
12. In a lithium bromide absorption system, if the water supply is compromised,
what would be the immediate effect on the system's performance?
The compressor would work harder to compensate for the lack of
water.
The system would switch to a different refrigerant automatically.
The system would operate more efficiently due to less water usage.
The cooling efficiency would decrease significantly due to
inadequate heat absorption.
