Certification Practice Exam Questions

HVAC Excellence Master Specialist Certification Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which component in an HVAC system is responsible for transferring

heat from one medium to another?

• Compressor
• Evaporator Coil
• Expansion Valve
• Blower Motor

The evaporator coil absorbs heat from the air inside the space and transfers it to the refrigerant, enabling cooling.

• What type of expansion device maintains a constant superheat in a

refrigeration system?

• Capillary Tube 1 / 4

• Thermostatic Expansion Valve (TXV)
• Fixed Orifice
• Check Valve

A TXV adjusts refrigerant flow based on superheat, optimizing evaporator performance.

• Which refrigerant is considered to have zero ozone depletion potential

and is commonly used in modern systems?

A) R-22

B) R-410A

• R-134a

D) R-12

R-134a is an HFC refrigerant with zero ozone depletion potential, making it environmentally safer.

• What is the primary function of a compressor in a refrigeration

system?

• Absorb heat
• Increase refrigerant pressure and temperature
• Meter refrigerant
• Remove moisture

The compressor pressurizes refrigerant vapor, raising its temperature for heat rejection in the condenser.

• Which type of motor is typically used for HVAC blower fans due to its

efficiency and variable speed capability? 2 / 4

• Single-phase induction motor
• Shaded-pole motor
• ECM (Electronically Commutated Motor)
• Split-phase motor

ECMs provide high efficiency and variable speed control, improving system performance and energy savings.

• What is the recommended superheat for a standard residential air

conditioning system at the evaporator outlet?

A) 0–5°F

B) 5–10°F

C) 10–15°F

D) 20–25°F

A superheat of 10–15°F ensures the evaporator is fully utilized without risking liquid refrigerant entering the compressor.

• What is the main purpose of a condenser in a refrigeration system?
• Evaporate refrigerant
• Reject heat from the refrigerant to the environment
• Increase refrigerant pressure only
• Filter contaminants

The condenser releases heat absorbed in the evaporator to the outside air or water, condensing the refrigerant to a liquid.

• Which component prevents liquid refrigerant from returning to the

compressor? 3 / 4

• Filter Drier
• Expansion Valve
• Suction Line Accumulator
• Condenser Coil

The suction line accumulator captures excess liquid refrigerant, protecting the compressor from damage.

9. In a heat pump system, the reversing valve allows:

• Compressor protection
• Refrigerant metering
• Switching between heating and cooling modes
• Air filtration

The reversing valve changes refrigerant flow direction, enabling the heat pump to heat or cool a space.

• What is the primary cause of icing on an evaporator coil?
• Low indoor airflow
• Low refrigerant charge
• Both A and B
• High condenser pressure

Low airflow or insufficient refrigerant can cause the coil temperature to drop below freezing, forming ice.

• Which tool is commonly used to measure HVAC system

superheat and subcooling?

• Thermometer
• / 4