PE HVAC & Refrigeration Systems Practice Exam Questions,
Correct Answers, and Detailed Explanations for
Students||Already Graded A+
1. The purpose of a cooling tower in an HVAC system is to:
A) Increase water temperature
B) Reject heat to the atmosphere
C) Compress refrigerant
D) Filter air
Answer: B) Reject heat to the atmosphere
Rationale: Cooling towers remove heat from water-cooled systems by
transferring heat to the ambient air.
2. In a vapor-compression refrigeration cycle, the component that raises the
pressure of the refrigerant is the:
A) Evaporator
B) Condenser
C) Compressor
D) Expansion valve
Answer: C) Compressor
Rationale: The compressor increases the pressure and temperature of the
refrigerant vapor before it enters the condenser.
3. Which refrigerant is considered environmentally safe and has zero ozone
depletion potential (ODP)?
A) R-22
B) R-134a
C) R-410A
D) R-12
Answer: C) R-410A
Rationale: R-410A is a hydrofluorocarbon (HFC) refrigerant with no ozone
depletion potential, unlike older CFCs.
,4. The primary function of an expansion valve is to:
A) Heat the refrigerant
B) Increase pressure
C) Reduce refrigerant pressure and control flow
D) Condense the refrigerant
Answer: C) Reduce refrigerant pressure and control flow
Rationale: Expansion valves meter refrigerant into the evaporator at the
correct pressure for proper heat absorption.
5. Sensible heat is:
A) Heat associated with phase change
B) Heat that changes temperature without changing state
C) Heat absorbed during melting
D) Heat released during condensation
Answer: B) Heat that changes temperature without changing state
Rationale: Sensible heat affects the temperature of a substance but does not
cause a phase change.
6. Latent heat is:
A) Heat associated with temperature change
B) Heat absorbed or released during a phase change
C) Heat lost through radiation
D) Heat stored in building materials
Answer: B) Heat absorbed or released during a phase change
Rationale: Latent heat is the energy required to change the phase of a
substance without changing its temperature.
7. Which air distribution device provides diffused air throughout a space?
A) Grille
B) Diffuser
, C) Register
D) Louver
Answer: B) Diffuser
Rationale: Diffusers spread air evenly into a room to maintain comfort and
minimize drafts.
8. The Coefficient of Performance (COP) of a heat pump is defined as:
A) Heat output / Electrical input
B) Electrical input / Heat output
C) Cooling load / Heat rejected
D) Heating load / Cooling load
Answer: A) Heat output / Electrical input
Rationale: COP measures the efficiency of a heat pump; higher COP indicates
better performance.
9. In an HVAC system, a “fan coil unit” is primarily used to:
A) Cool refrigerant
B) Transfer heat between water and air
C) Compress air
D) Filter pollutants
Answer: B) Transfer heat between water and air
Rationale: Fan coil units use water from a central plant to heat or cool air in a
room.
10. Which type of chiller uses absorption rather than mechanical
compression?
A) Centrifugal chiller
B) Scroll chiller
C) Absorption chiller
D) Screw chiller
Correct Answers, and Detailed Explanations for
Students||Already Graded A+
1. The purpose of a cooling tower in an HVAC system is to:
A) Increase water temperature
B) Reject heat to the atmosphere
C) Compress refrigerant
D) Filter air
Answer: B) Reject heat to the atmosphere
Rationale: Cooling towers remove heat from water-cooled systems by
transferring heat to the ambient air.
2. In a vapor-compression refrigeration cycle, the component that raises the
pressure of the refrigerant is the:
A) Evaporator
B) Condenser
C) Compressor
D) Expansion valve
Answer: C) Compressor
Rationale: The compressor increases the pressure and temperature of the
refrigerant vapor before it enters the condenser.
3. Which refrigerant is considered environmentally safe and has zero ozone
depletion potential (ODP)?
A) R-22
B) R-134a
C) R-410A
D) R-12
Answer: C) R-410A
Rationale: R-410A is a hydrofluorocarbon (HFC) refrigerant with no ozone
depletion potential, unlike older CFCs.
,4. The primary function of an expansion valve is to:
A) Heat the refrigerant
B) Increase pressure
C) Reduce refrigerant pressure and control flow
D) Condense the refrigerant
Answer: C) Reduce refrigerant pressure and control flow
Rationale: Expansion valves meter refrigerant into the evaporator at the
correct pressure for proper heat absorption.
5. Sensible heat is:
A) Heat associated with phase change
B) Heat that changes temperature without changing state
C) Heat absorbed during melting
D) Heat released during condensation
Answer: B) Heat that changes temperature without changing state
Rationale: Sensible heat affects the temperature of a substance but does not
cause a phase change.
6. Latent heat is:
A) Heat associated with temperature change
B) Heat absorbed or released during a phase change
C) Heat lost through radiation
D) Heat stored in building materials
Answer: B) Heat absorbed or released during a phase change
Rationale: Latent heat is the energy required to change the phase of a
substance without changing its temperature.
7. Which air distribution device provides diffused air throughout a space?
A) Grille
B) Diffuser
, C) Register
D) Louver
Answer: B) Diffuser
Rationale: Diffusers spread air evenly into a room to maintain comfort and
minimize drafts.
8. The Coefficient of Performance (COP) of a heat pump is defined as:
A) Heat output / Electrical input
B) Electrical input / Heat output
C) Cooling load / Heat rejected
D) Heating load / Cooling load
Answer: A) Heat output / Electrical input
Rationale: COP measures the efficiency of a heat pump; higher COP indicates
better performance.
9. In an HVAC system, a “fan coil unit” is primarily used to:
A) Cool refrigerant
B) Transfer heat between water and air
C) Compress air
D) Filter pollutants
Answer: B) Transfer heat between water and air
Rationale: Fan coil units use water from a central plant to heat or cool air in a
room.
10. Which type of chiller uses absorption rather than mechanical
compression?
A) Centrifugal chiller
B) Scroll chiller
C) Absorption chiller
D) Screw chiller
