Refrigeration Systems Certification
Practice Exam (2026 Updated)||
questions and answers with
rationales/graded A+/2026
update/100% correct /instant
download
Total Questions: 82
Passing Score: 70% (58 correct)
Time Allowed: 120 minutes
Format: Multiple Choice – Highlighted answers are correct.
Section 1: Refrigeration Cycle & Components (Questions 1–20)
1. What is the state of refrigerant at the outlet of the evaporator in a standard
vapor-compression cycle?
A) High-pressure liquid
B) Low-pressure superheated vapor
C) High-pressure superheated vapor
D) Low-pressure subcooled liquid
Rationale: The evaporator absorbs heat, boiling the refrigerant into a vapor; slight
superheat ensures no liquid returns to compressor.
2. Which component separates high-pressure and low-pressure sides of the system?
A) Evaporator
B) Compressor and expansion device
C) Condenser only
D) Receiver
,Rationale: The compressor creates the pressure difference by drawing low-
pressure vapor and discharging high-pressure vapor; the expansion device drops
pressure.
3. Subcooling occurs in which part of the system?
A) Evaporator
B) Suction line
C) Condenser (or liquid line after condenser)
D) Compressor discharge line
Rationale: Subcooling is the cooling of liquid refrigerant below its condensing
temperature, typically in the lower portion of the condenser.
4. The primary purpose of an accumulator is to:
A) Store excess refrigerant
B) Prevent liquid slugging in the compressor
C) Filter debris
D) Increase subcooling
Rationale: Accumulator traps liquid refrigerant and allows only vapor to return to
compressor, preventing damage.
5. In a capillary tube system, the refrigerant flow rate is controlled by:
A) Evaporator pressure
B) Tube length and internal diameter
C) Solenoid valve
D) Thermostatic expansion valve
Rationale: Capillary tubes are fixed-orifice devices; length and diameter
determine pressure drop and flow.
6. The TEV sensing bulb should be mounted on the:
A) Liquid line before the evaporator
B) Discharge line
C) Suction line near evaporator outlet
D) Condenser outlet
Rationale: The bulb senses suction superheat to modulate valve opening.
7. What is the typical superheat target for a medium-temperature refrigeration
system?
A) 0–2°F
, B) 5–12°F
C) 20–30°F
D) 40–50°F
Rationale: 5–12°F ensures no liquid returns to compressor while maintaining
efficiency.
8. Which refrigerant has the lowest GWP among common HFO blends?
A) R-134a
B) R-1234yf
C) R-404A
D) R-410A
Rationale: R-1234yf has GWP < 1; R-404A ~ 3922, R-134a ~ 1430.
9. A compressor that uses a scroll mechanism is typically more efficient and
quieter than:
A) Rotary
B) Reciprocating
C) Centrifugal
D) Screw
Rationale: Scroll compressors have fewer moving parts and lower vibration than
reciprocating.
10. The condenser fan cycles on a low-ambient control to:
A) Increase subcooling
B) Maintain minimum head pressure
C) Reduce superheat
D) Increase evaporator temperature
Rationale: In cold weather, reduced condenser airflow prevents head pressure
from dropping too low.
11. Refrigerant migration to the compressor crankcase during off-cycle is
prevented by:
A) Liquid line solenoid valve
B) Crankcase heater
C) Filter-drier
D) Sight glass
Practice Exam (2026 Updated)||
questions and answers with
rationales/graded A+/2026
update/100% correct /instant
download
Total Questions: 82
Passing Score: 70% (58 correct)
Time Allowed: 120 minutes
Format: Multiple Choice – Highlighted answers are correct.
Section 1: Refrigeration Cycle & Components (Questions 1–20)
1. What is the state of refrigerant at the outlet of the evaporator in a standard
vapor-compression cycle?
A) High-pressure liquid
B) Low-pressure superheated vapor
C) High-pressure superheated vapor
D) Low-pressure subcooled liquid
Rationale: The evaporator absorbs heat, boiling the refrigerant into a vapor; slight
superheat ensures no liquid returns to compressor.
2. Which component separates high-pressure and low-pressure sides of the system?
A) Evaporator
B) Compressor and expansion device
C) Condenser only
D) Receiver
,Rationale: The compressor creates the pressure difference by drawing low-
pressure vapor and discharging high-pressure vapor; the expansion device drops
pressure.
3. Subcooling occurs in which part of the system?
A) Evaporator
B) Suction line
C) Condenser (or liquid line after condenser)
D) Compressor discharge line
Rationale: Subcooling is the cooling of liquid refrigerant below its condensing
temperature, typically in the lower portion of the condenser.
4. The primary purpose of an accumulator is to:
A) Store excess refrigerant
B) Prevent liquid slugging in the compressor
C) Filter debris
D) Increase subcooling
Rationale: Accumulator traps liquid refrigerant and allows only vapor to return to
compressor, preventing damage.
5. In a capillary tube system, the refrigerant flow rate is controlled by:
A) Evaporator pressure
B) Tube length and internal diameter
C) Solenoid valve
D) Thermostatic expansion valve
Rationale: Capillary tubes are fixed-orifice devices; length and diameter
determine pressure drop and flow.
6. The TEV sensing bulb should be mounted on the:
A) Liquid line before the evaporator
B) Discharge line
C) Suction line near evaporator outlet
D) Condenser outlet
Rationale: The bulb senses suction superheat to modulate valve opening.
7. What is the typical superheat target for a medium-temperature refrigeration
system?
A) 0–2°F
, B) 5–12°F
C) 20–30°F
D) 40–50°F
Rationale: 5–12°F ensures no liquid returns to compressor while maintaining
efficiency.
8. Which refrigerant has the lowest GWP among common HFO blends?
A) R-134a
B) R-1234yf
C) R-404A
D) R-410A
Rationale: R-1234yf has GWP < 1; R-404A ~ 3922, R-134a ~ 1430.
9. A compressor that uses a scroll mechanism is typically more efficient and
quieter than:
A) Rotary
B) Reciprocating
C) Centrifugal
D) Screw
Rationale: Scroll compressors have fewer moving parts and lower vibration than
reciprocating.
10. The condenser fan cycles on a low-ambient control to:
A) Increase subcooling
B) Maintain minimum head pressure
C) Reduce superheat
D) Increase evaporator temperature
Rationale: In cold weather, reduced condenser airflow prevents head pressure
from dropping too low.
11. Refrigerant migration to the compressor crankcase during off-cycle is
prevented by:
A) Liquid line solenoid valve
B) Crankcase heater
C) Filter-drier
D) Sight glass
