Refrigeration System Quiz

A refrigeration system using R-404A has an evaporator pressure of 35 psig. What is the approximate evaporator saturation temperature?

• -10°F

• -5°F

• 0°F

• All of the above

A compressor is running at 1,800 RPM with a bore of 2.75 inches, a stroke of 4 inches, and has 4 cylinders. What is the total displacement per minute?

• 107,800 in³/min

• 85,500 in³/min

• 97,000 in³/min

• All of the above

A refrigeration system with a capillary tube shows high superheat and low suction pressure. What could be the cause?

• System undercharge

• Capillary tube restriction

• Low ambient temperature

• All of the above

A compressor draws 7.2 kW and has a cooling capacity of 20,500 BTU/hr. What is the coefficient of performance (COP)?

• 2.1

• 2.8

• 3.5

• All of the above

What is the function of a crankcase heater in a compressor?

• To increase the compressor's efficiency

• To prevent refrigerant migration

• To cool the compressor

• To reduce noise

A refrigeration system has a discharge pressure of 275 psig and a suction pressure of 60 psig. What is the approximate compression ratio?

• 4.1:1

• 4.8:1

• 5.2:1

• All of the above

A heat pump in heating mode has a condenser pressure of 340 psig using R-410A. What is the approximate condenser saturation temperature?

• 90°F

• 100°F

• 110°F

• All of the above

A walk-in freezer using R-404A has a 15°F evaporator TD. If the box temperature is -10°F, what is the target evaporator temperature?

• -30°F

• -25°F

• -15°F

• All of the above

What is the primary function of a TXV (Thermostatic Expansion Valve)?

• To regulate refrigerant flow based on superheat

• To maintain constant evaporator pressure

• To prevent compressor short cycling

• All of the above

A refrigeration system has high head pressure and high suction pressure. What could be the likely cause?

• Compressor valve damage

• Refrigerant overcharge

• Insufficient airflow

• All of the above