Automotive HVAC Systems Certification
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
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1. What is the primary function of the compressor in an automotive air-
conditioning system?
A. To remove moisture from the cabin air
B. To circulate refrigerant and raise its pressure
C. To cool the condenser
D. To regulate blower-motor speed
Answer: B. To circulate refrigerant and raise its pressure
Rationale: The compressor is the primary refrigerant-flow device. It draws
low-pressure refrigerant vapor from the evaporator, compresses it, and
delivers high-pressure vapor to the condenser.
, 2. Which component changes high-pressure refrigerant vapor into a
high-pressure liquid?
A. Evaporator
B. Accumulator
C. Condenser
D. Expansion valve
Answer: C. Condenser
Rationale: The condenser rejects heat from the refrigerant to the outside
air, causing the high-pressure vapor to condense into a high-pressure
liquid.
3. What is the primary purpose of the evaporator in an automotive HVAC
system?
A. To absorb heat from the passenger compartment
B. To increase refrigerant pressure
C. To remove oil from refrigerant
D. To cool the compressor
Answer: A. To absorb heat from the passenger compartment
Rationale: Low-pressure refrigerant entering the evaporator absorbs heat
from air passing across the evaporator core, thereby cooling and
dehumidifying the passenger compartment.
, 4. Which refrigerant condition normally exists at the compressor inlet
during proper operation?
A. High-pressure liquid
B. Low-pressure vapor
C. High-pressure vapor
D. Low-pressure liquid
Answer: B. Low-pressure vapor
Rationale: The compressor should receive refrigerant primarily as a low-
pressure vapor. Liquid entering the compressor can cause severe
mechanical damage, a condition commonly called liquid slugging.
5. What is the main purpose of an expansion valve?
A. Increase compressor speed
B. Raise refrigerant pressure
C. Meter refrigerant into the evaporator and reduce its pressure
D. Remove contaminants from the condenser
Answer: C. Meter refrigerant into the evaporator and reduce its pressure
Rationale: The expansion valve controls refrigerant flow into the
evaporator while producing a pressure drop that allows the refrigerant to
evaporate at a lower temperature.
, 6. Which component is commonly used with a fixed-orifice-tube system
to prevent liquid refrigerant from reaching the compressor?
A. Accumulator
B. Receiver-drier
C. Condenser
D. Heater core
Answer: A. Accumulator
Rationale: An accumulator is installed on the evaporator outlet side of
many fixed-orifice systems. It separates liquid refrigerant from vapor and
helps prevent liquid from entering the compressor.
7. Which component is commonly located on the high-pressure side of a
thermostatic expansion-valve system?
A. Accumulator
B. Receiver-drier
C. Blower resistor
D. Evaporator temperature sensor
Answer: B. Receiver-drier
Rationale: Receiver-driers store excess liquid refrigerant, remove moisture
with desiccant, and help filter contaminants before refrigerant reaches the
expansion valve.
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. What is the primary function of the compressor in an automotive air-
conditioning system?
A. To remove moisture from the cabin air
B. To circulate refrigerant and raise its pressure
C. To cool the condenser
D. To regulate blower-motor speed
Answer: B. To circulate refrigerant and raise its pressure
Rationale: The compressor is the primary refrigerant-flow device. It draws
low-pressure refrigerant vapor from the evaporator, compresses it, and
delivers high-pressure vapor to the condenser.
, 2. Which component changes high-pressure refrigerant vapor into a
high-pressure liquid?
A. Evaporator
B. Accumulator
C. Condenser
D. Expansion valve
Answer: C. Condenser
Rationale: The condenser rejects heat from the refrigerant to the outside
air, causing the high-pressure vapor to condense into a high-pressure
liquid.
3. What is the primary purpose of the evaporator in an automotive HVAC
system?
A. To absorb heat from the passenger compartment
B. To increase refrigerant pressure
C. To remove oil from refrigerant
D. To cool the compressor
Answer: A. To absorb heat from the passenger compartment
Rationale: Low-pressure refrigerant entering the evaporator absorbs heat
from air passing across the evaporator core, thereby cooling and
dehumidifying the passenger compartment.
, 4. Which refrigerant condition normally exists at the compressor inlet
during proper operation?
A. High-pressure liquid
B. Low-pressure vapor
C. High-pressure vapor
D. Low-pressure liquid
Answer: B. Low-pressure vapor
Rationale: The compressor should receive refrigerant primarily as a low-
pressure vapor. Liquid entering the compressor can cause severe
mechanical damage, a condition commonly called liquid slugging.
5. What is the main purpose of an expansion valve?
A. Increase compressor speed
B. Raise refrigerant pressure
C. Meter refrigerant into the evaporator and reduce its pressure
D. Remove contaminants from the condenser
Answer: C. Meter refrigerant into the evaporator and reduce its pressure
Rationale: The expansion valve controls refrigerant flow into the
evaporator while producing a pressure drop that allows the refrigerant to
evaporate at a lower temperature.
, 6. Which component is commonly used with a fixed-orifice-tube system
to prevent liquid refrigerant from reaching the compressor?
A. Accumulator
B. Receiver-drier
C. Condenser
D. Heater core
Answer: A. Accumulator
Rationale: An accumulator is installed on the evaporator outlet side of
many fixed-orifice systems. It separates liquid refrigerant from vapor and
helps prevent liquid from entering the compressor.
7. Which component is commonly located on the high-pressure side of a
thermostatic expansion-valve system?
A. Accumulator
B. Receiver-drier
C. Blower resistor
D. Evaporator temperature sensor
Answer: B. Receiver-drier
Rationale: Receiver-driers store excess liquid refrigerant, remove moisture
with desiccant, and help filter contaminants before refrigerant reaches the
expansion valve.
