South Carolina Residential HVAC Contractor
Examination (Technical Exam) Questions and
Correct Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a residential HVAC system?
A. To increase electrical consumption
B. To provide only ventilation
C. To control indoor temperature, humidity, air movement, and air
quality
D. To eliminate the need for insulation
Answer: C. To control indoor temperature, humidity, air movement,
and air quality
Rationale: A properly designed HVAC system provides thermal comfort
while also supporting appropriate ventilation, humidity control, and
indoor air quality. Although temperature control is a major function,
residential HVAC systems perform several related functions.
, 2. Which component of a split air-conditioning system is normally
installed outdoors?
A. Evaporator coil
B. Air handler
C. Condenser coil
D. Supply-air register
Answer: C. Condenser coil
Rationale: In a conventional split system, the outdoor condensing unit
contains the compressor and condenser coil. The indoor section
generally contains the evaporator coil and blower.
3. What happens to refrigerant in the evaporator during normal
cooling operation?
A. It rejects heat and condenses
B. It absorbs heat and evaporates
C. It freezes completely
D. It becomes a solid
Answer: B. It absorbs heat and evaporates
Rationale: The evaporator is the heat-absorbing portion of the
refrigeration cycle. Refrigerant entering the evaporator at low pressure
,absorbs heat from indoor air and changes from a liquid or liquid-vapor
mixture into vapor.
4. What is the primary function of the compressor?
A. To remove dust from return air
B. To circulate refrigerant and raise its pressure and temperature
C. To reduce duct friction
D. To control room humidity directly
Answer: B. To circulate refrigerant and raise its pressure and
temperature
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor. This allows the refrigerant to reject heat in the
condenser.
5. Which device reduces refrigerant pressure before the refrigerant
enters the evaporator?
A. Compressor
B. Condenser fan
C. Metering device
D. Accumulator
Answer: C. Metering device
, Rationale: The metering device creates a pressure drop between the
high-pressure liquid side and the low-pressure evaporator side.
Common examples include thermostatic expansion valves and fixed
orifice devices.
6. What is the purpose of the condenser coil?
A. To absorb heat from the conditioned space
B. To reject heat from the refrigerant to the surrounding environment
C. To increase indoor humidity
D. To filter return air
Answer: B. To reject heat from the refrigerant to the surrounding
environment
Rationale: High-pressure refrigerant vapor enters the condenser and
releases heat to outdoor air. As heat is removed, the refrigerant
changes from vapor to liquid.
7. What does superheat describe in a refrigeration system?
A. Liquid refrigerant below its saturation temperature
B. Vapor refrigerant above its saturation temperature
C. Condenser pressure below atmospheric pressure
D. Air temperature below freezing
Answer: B. Vapor refrigerant above its saturation temperature
Examination (Technical Exam) Questions and
Correct Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a residential HVAC system?
A. To increase electrical consumption
B. To provide only ventilation
C. To control indoor temperature, humidity, air movement, and air
quality
D. To eliminate the need for insulation
Answer: C. To control indoor temperature, humidity, air movement,
and air quality
Rationale: A properly designed HVAC system provides thermal comfort
while also supporting appropriate ventilation, humidity control, and
indoor air quality. Although temperature control is a major function,
residential HVAC systems perform several related functions.
, 2. Which component of a split air-conditioning system is normally
installed outdoors?
A. Evaporator coil
B. Air handler
C. Condenser coil
D. Supply-air register
Answer: C. Condenser coil
Rationale: In a conventional split system, the outdoor condensing unit
contains the compressor and condenser coil. The indoor section
generally contains the evaporator coil and blower.
3. What happens to refrigerant in the evaporator during normal
cooling operation?
A. It rejects heat and condenses
B. It absorbs heat and evaporates
C. It freezes completely
D. It becomes a solid
Answer: B. It absorbs heat and evaporates
Rationale: The evaporator is the heat-absorbing portion of the
refrigeration cycle. Refrigerant entering the evaporator at low pressure
,absorbs heat from indoor air and changes from a liquid or liquid-vapor
mixture into vapor.
4. What is the primary function of the compressor?
A. To remove dust from return air
B. To circulate refrigerant and raise its pressure and temperature
C. To reduce duct friction
D. To control room humidity directly
Answer: B. To circulate refrigerant and raise its pressure and
temperature
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor. This allows the refrigerant to reject heat in the
condenser.
5. Which device reduces refrigerant pressure before the refrigerant
enters the evaporator?
A. Compressor
B. Condenser fan
C. Metering device
D. Accumulator
Answer: C. Metering device
, Rationale: The metering device creates a pressure drop between the
high-pressure liquid side and the low-pressure evaporator side.
Common examples include thermostatic expansion valves and fixed
orifice devices.
6. What is the purpose of the condenser coil?
A. To absorb heat from the conditioned space
B. To reject heat from the refrigerant to the surrounding environment
C. To increase indoor humidity
D. To filter return air
Answer: B. To reject heat from the refrigerant to the surrounding
environment
Rationale: High-pressure refrigerant vapor enters the condenser and
releases heat to outdoor air. As heat is removed, the refrigerant
changes from vapor to liquid.
7. What does superheat describe in a refrigeration system?
A. Liquid refrigerant below its saturation temperature
B. Vapor refrigerant above its saturation temperature
C. Condenser pressure below atmospheric pressure
D. Air temperature below freezing
Answer: B. Vapor refrigerant above its saturation temperature
