Refrigeration System Quiz

A refrigeration system compressor operates at 1,600 RPM with a displacement of 0.75 cubic feet per minute (CFM) per 100 RPM. What is its total displacement per minute?

• 10 CFM

• 12 CFM

• 15 CFM

• All of the above

A refrigeration system has a condenser pressure reading of 230 psig and a suction pressure reading of 60 psig using R-22. Assuming approximate absolute pressures of 265 psi and 80 psi respectively, what is the compression ratio?

• 3.1:1

• 2.5:1

• 4.0:1

• 5.0:1

During routine maintenance, you find that the liquid line filter-drier is saturated with moisture. What is the most immediate risk?

• Corrosion and acid formation

• Reduced refrigerant flow

• Increased subcooling

• All of the above

A system delivers 48,000 BTU/hr of cooling capacity with a power input of 4.0 kW. What is its Energy Efficiency Ratio (EER)?

• 10.0

• 11.5

• 12.0

• All of the above

If an evaporator coil becomes iced over, which of the following could be contributing factors?

• Restricted airflow

• Low refrigerant charge

• Faulty TXV operation

• All of the above

During a diagnostic, a technician suspects that non-condensable gases are affecting performance. What is a likely indicator?

• Elevated head pressure

• Excessive subcooling

• Low compressor amperage

• All of the above

A TXV is set to provide a superheat of 8°F at an evaporator outlet temperature of 40°F. If the measured suction line temperature is 48°F, is the TXV operating correctly?

• Yes, because 48°F - 40°F = 8°F

• No, because the superheat should be higher

• No, because the superheat should be lower

• All of the above

What is the correct operation indicator for a 12°F superheat with proper load?

• Indicates a fault

• Indicates correct operation

• Indicates high pressure

• Indicates low pressure

Calculate the temperature difference if the box temperature is 36°F and the TD is 8°F.

• 44°F

• 28°F

• 30°F

• 26°F

What is the least likely cause of an oversized compressor?

• Restricted airflow

• All of the above

• Incorrect sizing

• Faulty installation