Delaware HVACR Apprenticeship-
Bypass Examination Practice Exam 2026
| 100+ Questions & Answers with
Detailed Rationales | Complete
Delaware HVACR Apprenticeship-
Bypass Exam Prep, Study Guide, Test
Review & Qualification Preparation
1. What is the primary purpose of a refrigeration compressor?
A. Remove moisture from the evaporator
B. Circulate refrigerant and raise its pressure and temperature
C. Reduce condenser pressure
D. Meter refrigerant into the condenser
Answer: B. Circulate refrigerant and raise its pressure and temperature
Rationale: The compressor draws low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature vapor
before sending it to the condenser.
2. Which component removes heat from the conditioned space?
,A. Condenser
B. Compressor
C. Evaporator
D. Receiver
Answer: C. Evaporator
Rationale: The evaporator absorbs heat from the air, water, or product being
cooled as refrigerant evaporates inside the coil.
3. What is the normal flow sequence in a basic vapor-compression
refrigeration system?
A. Compressor → evaporator → condenser → expansion device
B. Compressor → condenser → expansion device → evaporator
C. Condenser → compressor → evaporator → expansion device
D. Evaporator → condenser → compressor → expansion device
Answer: B. Compressor → condenser → expansion device → evaporator
Rationale: Refrigerant leaves the compressor, condenses in the condenser, is
metered through the expansion device, and evaporates in the evaporator before
returning to the compressor.
4. What does a thermostatic expansion valve primarily control?
A. Compressor voltage
B. Condenser airflow
C. Refrigerant flow into the evaporator
D. Condenser fan speed only
Answer: C. Refrigerant flow into the evaporator
Rationale: A TXV meters refrigerant according to evaporator load and is
designed to maintain an appropriate superheat at the evaporator outlet.
5. What is superheat?
,A. Liquid temperature below saturation temperature
B. Vapor temperature above its saturation temperature
C. Condensing temperature below outdoor temperature
D. Pressure below atmospheric pressure
Answer: B. Vapor temperature above its saturation temperature
Rationale: Superheat is the number of degrees a vapor is heated above its
saturation temperature at a particular pressure.
6. What is subcooling?
A. Cooling a vapor below its boiling point
B. Cooling a liquid below its saturation temperature
C. Heating liquid refrigerant above saturation
D. Heating suction vapor
Answer: B. Cooling a liquid below its saturation temperature
Rationale: Subcooling is the temperature difference between the refrigerant's
saturation temperature and its actual liquid temperature.
7. What is the purpose of a condenser?
A. Absorb indoor heat
B. Meter refrigerant
C. Reject heat from the refrigerant
D. Increase evaporator pressure
Answer: C. Reject heat from the refrigerant
Rationale: The condenser removes heat from the high-pressure refrigerant
vapor, causing it to condense into a liquid.
8. What condition normally exists at the outlet of a properly operating
evaporator?
, A. High-pressure liquid
B. Low-pressure superheated vapor
C. High-pressure liquid-vapor mixture
D. High-pressure vapor
Answer: B. Low-pressure superheated vapor
Rationale: Refrigerant should normally leave the evaporator as a vapor with
sufficient superheat to protect the compressor from liquid refrigerant.
9. Which device is commonly used to protect a compressor from excessive
discharge pressure?
A. Low-pressure switch
B. High-pressure switch
C. Thermostat
D. Float switch
Answer: B. High-pressure switch
Rationale: A high-pressure safety control can shut down the compressor when
discharge or condensing pressure becomes dangerously high.
10.What is the primary function of a filter-drier?
A. Increase compressor capacity
B. Remove moisture and contaminants from the refrigerant circuit
C. Increase suction pressure
D. Control room temperature
Answer: B. Remove moisture and contaminants from the refrigerant circuit
Rationale: A filter-drier captures contaminants and absorbs moisture that could
damage components or cause system problems.
11.What happens to refrigerant pressure as it passes through a typical fixed
expansion device?
Bypass Examination Practice Exam 2026
| 100+ Questions & Answers with
Detailed Rationales | Complete
Delaware HVACR Apprenticeship-
Bypass Exam Prep, Study Guide, Test
Review & Qualification Preparation
1. What is the primary purpose of a refrigeration compressor?
A. Remove moisture from the evaporator
B. Circulate refrigerant and raise its pressure and temperature
C. Reduce condenser pressure
D. Meter refrigerant into the condenser
Answer: B. Circulate refrigerant and raise its pressure and temperature
Rationale: The compressor draws low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature vapor
before sending it to the condenser.
2. Which component removes heat from the conditioned space?
,A. Condenser
B. Compressor
C. Evaporator
D. Receiver
Answer: C. Evaporator
Rationale: The evaporator absorbs heat from the air, water, or product being
cooled as refrigerant evaporates inside the coil.
3. What is the normal flow sequence in a basic vapor-compression
refrigeration system?
A. Compressor → evaporator → condenser → expansion device
B. Compressor → condenser → expansion device → evaporator
C. Condenser → compressor → evaporator → expansion device
D. Evaporator → condenser → compressor → expansion device
Answer: B. Compressor → condenser → expansion device → evaporator
Rationale: Refrigerant leaves the compressor, condenses in the condenser, is
metered through the expansion device, and evaporates in the evaporator before
returning to the compressor.
4. What does a thermostatic expansion valve primarily control?
A. Compressor voltage
B. Condenser airflow
C. Refrigerant flow into the evaporator
D. Condenser fan speed only
Answer: C. Refrigerant flow into the evaporator
Rationale: A TXV meters refrigerant according to evaporator load and is
designed to maintain an appropriate superheat at the evaporator outlet.
5. What is superheat?
,A. Liquid temperature below saturation temperature
B. Vapor temperature above its saturation temperature
C. Condensing temperature below outdoor temperature
D. Pressure below atmospheric pressure
Answer: B. Vapor temperature above its saturation temperature
Rationale: Superheat is the number of degrees a vapor is heated above its
saturation temperature at a particular pressure.
6. What is subcooling?
A. Cooling a vapor below its boiling point
B. Cooling a liquid below its saturation temperature
C. Heating liquid refrigerant above saturation
D. Heating suction vapor
Answer: B. Cooling a liquid below its saturation temperature
Rationale: Subcooling is the temperature difference between the refrigerant's
saturation temperature and its actual liquid temperature.
7. What is the purpose of a condenser?
A. Absorb indoor heat
B. Meter refrigerant
C. Reject heat from the refrigerant
D. Increase evaporator pressure
Answer: C. Reject heat from the refrigerant
Rationale: The condenser removes heat from the high-pressure refrigerant
vapor, causing it to condense into a liquid.
8. What condition normally exists at the outlet of a properly operating
evaporator?
, A. High-pressure liquid
B. Low-pressure superheated vapor
C. High-pressure liquid-vapor mixture
D. High-pressure vapor
Answer: B. Low-pressure superheated vapor
Rationale: Refrigerant should normally leave the evaporator as a vapor with
sufficient superheat to protect the compressor from liquid refrigerant.
9. Which device is commonly used to protect a compressor from excessive
discharge pressure?
A. Low-pressure switch
B. High-pressure switch
C. Thermostat
D. Float switch
Answer: B. High-pressure switch
Rationale: A high-pressure safety control can shut down the compressor when
discharge or condensing pressure becomes dangerously high.
10.What is the primary function of a filter-drier?
A. Increase compressor capacity
B. Remove moisture and contaminants from the refrigerant circuit
C. Increase suction pressure
D. Control room temperature
Answer: B. Remove moisture and contaminants from the refrigerant circuit
Rationale: A filter-drier captures contaminants and absorbs moisture that could
damage components or cause system problems.
11.What happens to refrigerant pressure as it passes through a typical fixed
expansion device?
