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ASE A7 Heating & Air Conditioning
Questions with Answers Detailed
Rationales & Comprehensive Licensing
Prep
______________________________________________________________
1. What is the primary function of the automotive air-conditioning
compressor?
A. Remove moisture from the refrigerant
B. Circulate and compress refrigerant through the system
C. Cool the engine coolant
D. Control cabin air temperature directly
Answer: B. Circulate and compress refrigerant through the system
Rationale: The compressor raises refrigerant pressure and circulates refrigerant
through the A/C system, allowing heat to be transferred from the passenger
compartment to the outside air.
2. Which component removes heat from the refrigerant and changes it from a
vapor to a liquid?
A. Evaporator
B. Accumulator
C. Condenser
D. Expansion valve
Answer: C. Condenser
,Rationale: The condenser releases heat from the high-pressure refrigerant vapor
and causes it to condense into a high-pressure liquid.
3. What happens to refrigerant as it passes through a properly functioning
evaporator?
A. It absorbs heat from cabin air
B. It becomes a high-pressure liquid
C. It releases heat to outside air
D. It becomes engine coolant
Answer: A. It absorbs heat from cabin air
Rationale: Low-pressure refrigerant in the evaporator absorbs heat from air
passing through the evaporator, cooling the passenger compartment.
4. Which component meters refrigerant into the evaporator?
A. Condenser
B. Compressor clutch
C. Metering device
D. Receiver-drier
Answer: C. Metering device
Rationale: An expansion valve, orifice tube, or similar metering device controls
refrigerant flow into the evaporator and creates the pressure drop needed for
evaporation.
5. What is the purpose of a receiver-drier?
A. Store engine coolant
B. Remove moisture and filter contaminants from refrigerant
C. Increase compressor speed
D. Cool the condenser
Answer: B. Remove moisture and filter contaminants from refrigerant
,Rationale: A receiver-drier stores liquid refrigerant, filters debris, and uses
desiccant to absorb moisture from the refrigerant system.
6. In a system using an orifice tube, which component commonly stores
excess refrigerant and prevents liquid refrigerant from entering the
compressor?
A. Accumulator
B. Condenser
C. Expansion valve
D. Heater core
Answer: A. Accumulator
Rationale: The accumulator is installed on the evaporator outlet in many fixed-
orifice systems and separates liquid refrigerant from vapor before refrigerant
reaches the compressor.
7. What is the primary purpose of the A/C pressure switch or pressure sensor?
A. Control engine oil pressure
B. Monitor refrigerant pressure and protect or control system operation
C. Measure cabin humidity only
D. Regulate coolant flow through the heater core
Answer: B. Monitor refrigerant pressure and protect or control system
operation
Rationale: Pressure sensors and switches can prevent compressor operation at
dangerously low or high pressures and may also provide input for condenser-fan
and HVAC controls.
8. What condition can result from an undercharged A/C system?
A. Low evaporator temperature with excessive cooling
B. Reduced cooling performance
C. Excessively high refrigerant level
D. Increased compressor lubrication
, Answer: B. Reduced cooling performance
Rationale: Insufficient refrigerant reduces the amount of refrigerant available to
absorb heat, often resulting in poor cooling and abnormal system pressures.
9. What is a common result of an overcharged A/C system?
A. Excessively high discharge pressure
B. No refrigerant circulation
C. Extremely low condenser pressure
D. Increased evaporator airflow
Answer: A. Excessively high discharge pressure
Rationale: Excess refrigerant can reduce condenser space for vapor
condensation and cause high-side pressure to rise, especially under high
ambient temperatures.
10.What is the main purpose of refrigerant oil?
A. Lubricate moving A/C components
B. Increase engine coolant pressure
C. Clean the cabin air filter
D. Prevent tire wear
Answer: A. Lubricate moving A/C components
Rationale: Refrigerant oil circulates with the refrigerant and lubricates the
compressor and other components requiring lubrication.
11.Why should the correct type of refrigerant oil be used?
A. All refrigerant oils are interchangeable
B. Incorrect oil can damage components or affect system performance
C. Oil type affects tire pressure
D. Oil is used only to cool the condenser
Answer: B. Incorrect oil can damage components or affect system performance
ASE A7 Heating & Air Conditioning
Questions with Answers Detailed
Rationales & Comprehensive Licensing
Prep
______________________________________________________________
1. What is the primary function of the automotive air-conditioning
compressor?
A. Remove moisture from the refrigerant
B. Circulate and compress refrigerant through the system
C. Cool the engine coolant
D. Control cabin air temperature directly
Answer: B. Circulate and compress refrigerant through the system
Rationale: The compressor raises refrigerant pressure and circulates refrigerant
through the A/C system, allowing heat to be transferred from the passenger
compartment to the outside air.
2. Which component removes heat from the refrigerant and changes it from a
vapor to a liquid?
A. Evaporator
B. Accumulator
C. Condenser
D. Expansion valve
Answer: C. Condenser
,Rationale: The condenser releases heat from the high-pressure refrigerant vapor
and causes it to condense into a high-pressure liquid.
3. What happens to refrigerant as it passes through a properly functioning
evaporator?
A. It absorbs heat from cabin air
B. It becomes a high-pressure liquid
C. It releases heat to outside air
D. It becomes engine coolant
Answer: A. It absorbs heat from cabin air
Rationale: Low-pressure refrigerant in the evaporator absorbs heat from air
passing through the evaporator, cooling the passenger compartment.
4. Which component meters refrigerant into the evaporator?
A. Condenser
B. Compressor clutch
C. Metering device
D. Receiver-drier
Answer: C. Metering device
Rationale: An expansion valve, orifice tube, or similar metering device controls
refrigerant flow into the evaporator and creates the pressure drop needed for
evaporation.
5. What is the purpose of a receiver-drier?
A. Store engine coolant
B. Remove moisture and filter contaminants from refrigerant
C. Increase compressor speed
D. Cool the condenser
Answer: B. Remove moisture and filter contaminants from refrigerant
,Rationale: A receiver-drier stores liquid refrigerant, filters debris, and uses
desiccant to absorb moisture from the refrigerant system.
6. In a system using an orifice tube, which component commonly stores
excess refrigerant and prevents liquid refrigerant from entering the
compressor?
A. Accumulator
B. Condenser
C. Expansion valve
D. Heater core
Answer: A. Accumulator
Rationale: The accumulator is installed on the evaporator outlet in many fixed-
orifice systems and separates liquid refrigerant from vapor before refrigerant
reaches the compressor.
7. What is the primary purpose of the A/C pressure switch or pressure sensor?
A. Control engine oil pressure
B. Monitor refrigerant pressure and protect or control system operation
C. Measure cabin humidity only
D. Regulate coolant flow through the heater core
Answer: B. Monitor refrigerant pressure and protect or control system
operation
Rationale: Pressure sensors and switches can prevent compressor operation at
dangerously low or high pressures and may also provide input for condenser-fan
and HVAC controls.
8. What condition can result from an undercharged A/C system?
A. Low evaporator temperature with excessive cooling
B. Reduced cooling performance
C. Excessively high refrigerant level
D. Increased compressor lubrication
, Answer: B. Reduced cooling performance
Rationale: Insufficient refrigerant reduces the amount of refrigerant available to
absorb heat, often resulting in poor cooling and abnormal system pressures.
9. What is a common result of an overcharged A/C system?
A. Excessively high discharge pressure
B. No refrigerant circulation
C. Extremely low condenser pressure
D. Increased evaporator airflow
Answer: A. Excessively high discharge pressure
Rationale: Excess refrigerant can reduce condenser space for vapor
condensation and cause high-side pressure to rise, especially under high
ambient temperatures.
10.What is the main purpose of refrigerant oil?
A. Lubricate moving A/C components
B. Increase engine coolant pressure
C. Clean the cabin air filter
D. Prevent tire wear
Answer: A. Lubricate moving A/C components
Rationale: Refrigerant oil circulates with the refrigerant and lubricates the
compressor and other components requiring lubrication.
11.Why should the correct type of refrigerant oil be used?
A. All refrigerant oils are interchangeable
B. Incorrect oil can damage components or affect system performance
C. Oil type affects tire pressure
D. Oil is used only to cool the condenser
Answer: B. Incorrect oil can damage components or affect system performance
