HVAC Master Exam Questions and Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which of the following refrigerants is considered the most
environmentally friendly according to current regulations?
A. R-22
B. R-410A
C. R-134a
D. R-32
R-32 has a lower global warming potential (GWP) compared to
R-410A and R-134a, making it more environmentally friendly
while maintaining efficiency.
2. The primary function of a heat exchanger in an HVAC system is to:
A. Filter air
B. Transfer heat between mediums
C. Increase air pressure
D. Reduce humidity
Heat exchangers allow thermal energy to move between two
, mediums (air, water, refrigerant) without mixing them, which is
essential for heating and cooling efficiency.
3. What is the purpose of a metering device in a refrigeration cycle?
A. Increase refrigerant temperature
B. Maintain air quality
C. Regulate refrigerant flow into the evaporator
D. Remove moisture from the system
Metering devices, such as expansion valves or orifice tubes,
control the flow of refrigerant entering the evaporator to ensure
proper heat absorption and system efficiency.
4. In an air conditioning system, the evaporator coil is located:
A. Outside the building
B. Inside the air handler or indoor unit
C. At the condenser
D. In the duct return
The evaporator coil absorbs heat from indoor air, so it is always
installed inside the air handler or indoor unit where air passes
over it.
5. Which type of compressor is most commonly used in residential
air conditioning systems?
A. Screw
, B. Centrifugal
C. Reciprocating
D. Scroll
Reciprocating compressors are widely used in residential systems
due to their reliability, cost-effectiveness, and ability to handle
variable loads.
6. Superheat is defined as:
A. The temperature of the condenser above ambient
B. The temperature of refrigerant vapor above its boiling point at
a given pressure
C. The temperature of air leaving the evaporator
D. The difference between outdoor and indoor temperature
Superheat ensures that only vapor enters the compressor,
preventing liquid slugging, which could damage the system.
7. Subcooling in an HVAC system indicates:
A. Evaporator coil temperature
B. Refrigerant liquid temperature below its condensing
temperature
C. Outdoor temperature
D. Compressor suction pressure
Subcooling is used to verify that the refrigerant has fully
, condensed before entering the expansion device, ensuring
optimal system efficiency.
8. The primary purpose of a condenser in a refrigeration cycle is to:
A. Absorb heat from the indoor air
B. Increase refrigerant superheat
C. Reject heat from the refrigerant to the outside
D. Control humidity levels
The condenser transfers heat from the refrigerant to the outdoor
air (or water in water-cooled systems), converting vapor back to
liquid.
9. A split-system air conditioner separates which components?
A. Thermostat and condenser
B. Evaporator and thermostat
C. Condenser and evaporator coil
D. Compressor and blower motor
In split systems, the evaporator coil is located indoors, while the
condenser and compressor are located outdoors, providing
efficiency and noise reduction.
10. What is the typical pressure relationship in a vapor-
compression refrigeration cycle?
A. Suction pressure > discharge pressure
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which of the following refrigerants is considered the most
environmentally friendly according to current regulations?
A. R-22
B. R-410A
C. R-134a
D. R-32
R-32 has a lower global warming potential (GWP) compared to
R-410A and R-134a, making it more environmentally friendly
while maintaining efficiency.
2. The primary function of a heat exchanger in an HVAC system is to:
A. Filter air
B. Transfer heat between mediums
C. Increase air pressure
D. Reduce humidity
Heat exchangers allow thermal energy to move between two
, mediums (air, water, refrigerant) without mixing them, which is
essential for heating and cooling efficiency.
3. What is the purpose of a metering device in a refrigeration cycle?
A. Increase refrigerant temperature
B. Maintain air quality
C. Regulate refrigerant flow into the evaporator
D. Remove moisture from the system
Metering devices, such as expansion valves or orifice tubes,
control the flow of refrigerant entering the evaporator to ensure
proper heat absorption and system efficiency.
4. In an air conditioning system, the evaporator coil is located:
A. Outside the building
B. Inside the air handler or indoor unit
C. At the condenser
D. In the duct return
The evaporator coil absorbs heat from indoor air, so it is always
installed inside the air handler or indoor unit where air passes
over it.
5. Which type of compressor is most commonly used in residential
air conditioning systems?
A. Screw
, B. Centrifugal
C. Reciprocating
D. Scroll
Reciprocating compressors are widely used in residential systems
due to their reliability, cost-effectiveness, and ability to handle
variable loads.
6. Superheat is defined as:
A. The temperature of the condenser above ambient
B. The temperature of refrigerant vapor above its boiling point at
a given pressure
C. The temperature of air leaving the evaporator
D. The difference between outdoor and indoor temperature
Superheat ensures that only vapor enters the compressor,
preventing liquid slugging, which could damage the system.
7. Subcooling in an HVAC system indicates:
A. Evaporator coil temperature
B. Refrigerant liquid temperature below its condensing
temperature
C. Outdoor temperature
D. Compressor suction pressure
Subcooling is used to verify that the refrigerant has fully
, condensed before entering the expansion device, ensuring
optimal system efficiency.
8. The primary purpose of a condenser in a refrigeration cycle is to:
A. Absorb heat from the indoor air
B. Increase refrigerant superheat
C. Reject heat from the refrigerant to the outside
D. Control humidity levels
The condenser transfers heat from the refrigerant to the outdoor
air (or water in water-cooled systems), converting vapor back to
liquid.
9. A split-system air conditioner separates which components?
A. Thermostat and condenser
B. Evaporator and thermostat
C. Condenser and evaporator coil
D. Compressor and blower motor
In split systems, the evaporator coil is located indoors, while the
condenser and compressor are located outdoors, providing
efficiency and noise reduction.
10. What is the typical pressure relationship in a vapor-
compression refrigeration cycle?
A. Suction pressure > discharge pressure
