Delaware Air-Conditioning Contractor
Examination Practice Exam 2026 | 100+
Questions & Answers with Detailed
Rationales | Complete Delaware Air-
Conditioning Contractor Licensing Exam
Prep, Study Guide, Test Review &
Qualification Preparation
1. What is the primary purpose of a refrigeration cycle in an air-conditioning
system?
A. To generate electricity
B. To transfer heat from one location to another
C. To increase indoor humidity
D. To produce combustion gases
Answer: To transfer heat from one location to another
Rationale: The refrigeration cycle removes heat from the conditioned space and
rejects that heat to another location, normally outdoors.
2. Which component raises the pressure and temperature of refrigerant
vapor?
A. Evaporator
, B. Condenser
C. Compressor
D. Expansion valve
Answer: Compressor
Rationale: The compressor takes low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature vapor.
3. What is the primary function of the evaporator coil?
A. Reject heat outdoors
B. Absorb heat from indoor air
C. Compress refrigerant
D. Store liquid refrigerant
Answer: Absorb heat from indoor air
Rationale: Refrigerant evaporates inside the evaporator coil while absorbing
heat from the air passing over the coil.
4. What is the primary function of the condenser coil?
A. Absorb indoor heat
B. Reduce electrical voltage
C. Reject heat from the refrigerant
D. Increase airflow
Answer: Reject heat from the refrigerant
Rationale: The condenser removes heat from the refrigerant and transfers it to
the outdoor environment.
5. Which device meters refrigerant into the evaporator?
A. Compressor
B. Thermostat
C. Expansion device
D. Condenser fan
Answer: Expansion device
,Rationale: A metering device such as a thermostatic expansion valve or
electronic expansion valve controls refrigerant flow into the evaporator.
6. What happens to refrigerant pressure as it passes through a typical
expansion device?
A. It increases substantially
B. It remains unchanged
C. It decreases substantially
D. It becomes atmospheric pressure
Answer: It decreases substantially
Rationale: The expansion device creates a pressure drop that allows the
refrigerant to enter the evaporator at a lower pressure and temperature.
7. Which refrigerant condition normally enters a compressor in a properly
operating system?
A. High-pressure liquid
B. Low-pressure vapor
C. High-pressure liquid-vapor mixture
D. Atmospheric air
Answer: Low-pressure vapor
Rationale: Compressors are designed to compress vapor. Liquid entering the
compressor can cause severe mechanical damage.
8. What is superheat?
A. Temperature of liquid below saturation temperature
B. Temperature of vapor above its saturation temperature
C. Condenser temperature below ambient
D. Pressure below atmospheric pressure
Answer: Temperature of vapor above its saturation temperature
Rationale: Superheat represents how much a vapor's actual temperature
exceeds its saturation temperature at a given pressure.
, 9. What is subcooling?
A. Cooling a liquid below its saturation temperature
B. Heating vapor above saturation
C. Heating liquid above saturation
D. Cooling the compressor below room temperature
Answer: Cooling a liquid below its saturation temperature
Rationale: Subcooling is the temperature difference between the refrigerant's
saturation temperature and the actual temperature of the liquid refrigerant.
10.What instrument is commonly used to measure refrigerant pressure?
A. Manifold gauge set
B. Megohmmeter
C. Thermocouple only
D. Ammeter
Answer: Manifold gauge set
Rationale: Refrigeration manifold gauges are used to measure system pressures
and assist with charging, evacuation, and troubleshooting.
11.What is the purpose of a vacuum pump during system evacuation?
A. Add refrigerant
B. Remove air and moisture
C. Increase condenser pressure
D. Add compressor oil
Answer: Remove air and moisture
Rationale: Proper evacuation removes non-condensable gases and moisture
before refrigerant is introduced into the system.
12.Why is moisture undesirable in a refrigeration system?
A. It improves compressor lubrication
B. It can form acids and cause corrosion
Examination Practice Exam 2026 | 100+
Questions & Answers with Detailed
Rationales | Complete Delaware Air-
Conditioning Contractor Licensing Exam
Prep, Study Guide, Test Review &
Qualification Preparation
1. What is the primary purpose of a refrigeration cycle in an air-conditioning
system?
A. To generate electricity
B. To transfer heat from one location to another
C. To increase indoor humidity
D. To produce combustion gases
Answer: To transfer heat from one location to another
Rationale: The refrigeration cycle removes heat from the conditioned space and
rejects that heat to another location, normally outdoors.
2. Which component raises the pressure and temperature of refrigerant
vapor?
A. Evaporator
, B. Condenser
C. Compressor
D. Expansion valve
Answer: Compressor
Rationale: The compressor takes low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature vapor.
3. What is the primary function of the evaporator coil?
A. Reject heat outdoors
B. Absorb heat from indoor air
C. Compress refrigerant
D. Store liquid refrigerant
Answer: Absorb heat from indoor air
Rationale: Refrigerant evaporates inside the evaporator coil while absorbing
heat from the air passing over the coil.
4. What is the primary function of the condenser coil?
A. Absorb indoor heat
B. Reduce electrical voltage
C. Reject heat from the refrigerant
D. Increase airflow
Answer: Reject heat from the refrigerant
Rationale: The condenser removes heat from the refrigerant and transfers it to
the outdoor environment.
5. Which device meters refrigerant into the evaporator?
A. Compressor
B. Thermostat
C. Expansion device
D. Condenser fan
Answer: Expansion device
,Rationale: A metering device such as a thermostatic expansion valve or
electronic expansion valve controls refrigerant flow into the evaporator.
6. What happens to refrigerant pressure as it passes through a typical
expansion device?
A. It increases substantially
B. It remains unchanged
C. It decreases substantially
D. It becomes atmospheric pressure
Answer: It decreases substantially
Rationale: The expansion device creates a pressure drop that allows the
refrigerant to enter the evaporator at a lower pressure and temperature.
7. Which refrigerant condition normally enters a compressor in a properly
operating system?
A. High-pressure liquid
B. Low-pressure vapor
C. High-pressure liquid-vapor mixture
D. Atmospheric air
Answer: Low-pressure vapor
Rationale: Compressors are designed to compress vapor. Liquid entering the
compressor can cause severe mechanical damage.
8. What is superheat?
A. Temperature of liquid below saturation temperature
B. Temperature of vapor above its saturation temperature
C. Condenser temperature below ambient
D. Pressure below atmospheric pressure
Answer: Temperature of vapor above its saturation temperature
Rationale: Superheat represents how much a vapor's actual temperature
exceeds its saturation temperature at a given pressure.
, 9. What is subcooling?
A. Cooling a liquid below its saturation temperature
B. Heating vapor above saturation
C. Heating liquid above saturation
D. Cooling the compressor below room temperature
Answer: Cooling a liquid below its saturation temperature
Rationale: Subcooling is the temperature difference between the refrigerant's
saturation temperature and the actual temperature of the liquid refrigerant.
10.What instrument is commonly used to measure refrigerant pressure?
A. Manifold gauge set
B. Megohmmeter
C. Thermocouple only
D. Ammeter
Answer: Manifold gauge set
Rationale: Refrigeration manifold gauges are used to measure system pressures
and assist with charging, evacuation, and troubleshooting.
11.What is the purpose of a vacuum pump during system evacuation?
A. Add refrigerant
B. Remove air and moisture
C. Increase condenser pressure
D. Add compressor oil
Answer: Remove air and moisture
Rationale: Proper evacuation removes non-condensable gases and moisture
before refrigerant is introduced into the system.
12.Why is moisture undesirable in a refrigeration system?
A. It improves compressor lubrication
B. It can form acids and cause corrosion
