Certification Practice Exam Questions And

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

• What is the primary purpose of a metering device in a refrigeration

system?

• Increase refrigerant pressure
• Regulate refrigerant flow into the evaporator
• Remove moisture from refrigerant
• Compress refrigerant

Rationale: The metering device controls the flow of refrigerant into the

evaporator to maintain proper system operation and prevent flooding.

• Which type of compressor is commonly used in residential air

conditioning systems?

• Reciprocating
• Screw 1 / 4

• Scroll
• Centrifugal

Rationale: Scroll compressors are widely used in residential systems due to

their efficiency, reliability, and quiet operation.

• What is the purpose of superheat in a refrigeration system?
• Prevent compressor overheating
• Increase refrigerant pressure
• Ensure all liquid refrigerant has vaporized before entering the

compressor

• Reduce condenser load

Rationale: Superheat guarantees that only vapor enters the compressor,

preventing liquid slugging and potential damage.

• Which refrigerant is classified as an HFC?

A. R-22

B. R-410A

C. R-12

D. R-502

Rationale: R-410A is a hydrofluorocarbon (HFC) refrigerant, used as a

replacement for R-22 in modern systems.

• What does the term "subcooling" refer to?
• Refrigerant temperature above boiling point
• Refrigerant temperature below condensing point 2 / 4

• Evaporator fan speed
• Expansion valve setting

Rationale: Subcooling measures how much the refrigerant is cooled below its

condensation temperature to ensure maximum system efficiency.

• A three-phase motor runs at 1800 RPM. What is the likely number of

poles if the supply frequency is 60 Hz?

• 2
• 4
• 6
• 8

Rationale: Motor speed (RPM) = 120 × frequency ÷ poles. 120 × 60 ÷ 6 =

1200 RPM; using synchronous formulas, 1800 RPM corresponds to a 4-pole

motor. Correction: 1800 RPM = 120 × 60 ÷ 4, so correct answer is 4 poles.

• What safety device prevents excessive pressure in a refrigeration

system?

• Expansion valve
• Thermostat
• High-pressure switch
• Evaporator coil

Rationale: A high-pressure switch opens to shut down the system if pressure

exceeds safe limits. 3 / 4

• Which gas is used in combustion analyzers to measure incomplete

combustion?

• Oxygen
• Nitrogen
• Carbon monoxide
• Carbon dioxide

Rationale: Carbon monoxide levels indicate incomplete combustion and

potential safety hazards.

• What type of heat exchanger is typically used in air handlers?
• Shell and tube
• Finned-tube
• Plate
• Spiral

Rationale: Finned-tube heat exchangers efficiently transfer heat between air

and fluid in air handlers.

• A system has 25°F of superheat. The suction line temperature is

40°F. What is the evaporator saturation temperature?

A. 55°F

B. 15°F

C. 40°F - 25°F = 15°F

• 65°F
• / 4