[HRC40] Hawaii Refrigeration Contractor C 40
Certification Exam Preparation
**Question 1.** Which law explains the inverse relationship between pressure and volume of a
refrigerant at constant temperature?
A) Charles’s Law
B) Boyle’s Law
C) Dalton’s Law
D) Gay‑Lussac’s Law
Answer: B
Explanation: Boyle’s Law states that for a fixed amount of gas at constant temperature, pressure
and volume are inversely proportional (P × V = constant).
**Question 2.** In a refrigeration system, what type of heat transfer occurs when the
refrigerant vaporizes in the evaporator?
A) Sensible heat
B) Latent heat
C) Conduction heat
D) Radiant heat
Answer: B
Explanation: Vaporization absorbs latent heat from the refrigerated space, providing the cooling
effect without a temperature change of the refrigerant.
**Question 3.** Which component controls the flow of refrigerant into the evaporator based
on superheat?
A) Capillary tube
B) Thermostatic Expansion Valve (TXV)
C) Automatic Expansion Valve (AEV)
D) Receiver
Answer: B
, [HRC40] Hawaii Refrigeration Contractor C 40
Certification Exam Preparation
Explanation: A TXV meters refrigerant to maintain a set superheat, ensuring proper evaporation
and preventing liquid floodback to the compressor.
**Question 4.** What is the primary purpose of an accumulator in a low‑side system?
A) Increase refrigerant pressure
B) Remove oil from the suction line
C) Capture excess liquid refrigerant
D) Provide additional cooling capacity
Answer: C
Explanation: An accumulator collects and vaporizes any liquid refrigerant that may travel back
toward the compressor, protecting it from liquid slugging.
**Question 5.** Which refrigerant safety classification indicates a “low toxicity, low
flammability” fluid?
A) A1
B) A2L
C) B2
D) C3
Answer: B
Explanation: ASHRAE safety class A2L denotes refrigerants with low toxicity (A) and low
flammability (2L).
**Question 6.** When reading a pressure‑temperature (P‑T) chart for R‑410A, what does the
curve represent?
A) Enthalpy vs. temperature
B) Saturation pressure at various temperatures
C) Superheat values
, [HRC40] Hawaii Refrigeration Contractor C 40
Certification Exam Preparation
D) Subcooling limits
Answer: B
Explanation: The P‑T chart plots saturation pressure for corresponding saturation temperatures,
allowing determination of refrigerant state.
**Question 7.** In a walk‑in cooler, the most effective way to reduce heat gain through the
door is to use:
A) A thicker metal door
B) A double‑glazed door with low‑emissivity coating
C) A solid wood door
D) A single‑pane glass door
Answer: B
Explanation: Double‑glazed doors with low‑E coating provide high insulation values, minimizing
conductive and radiant heat transfer.
**Question 8.** Which type of condenser is most common in Hawaiian commercial
refrigeration due to limited water availability?
A) Water‑cooled condenser
B) Air‑cooled condenser
C) Evaporative condenser
D) Hybrid condenser
Answer: B
Explanation: Air‑cooled condensers avoid the need for a water source, making them suitable for
islands where water resources are limited.
**Question 9.** The purpose of a defrost timer in a mechanically‑controlled defrost system is
to:
, [HRC40] Hawaii Refrigeration Contractor C 40
Certification Exam Preparation
A) Measure the temperature of the evaporator coil
B) Initiate defrost cycles at preset intervals
C) Regulate compressor speed
D) Control suction line pressure
Answer: B
Explanation: A defrost timer starts a defrost cycle after a set operating time, ensuring periodic
removal of ice buildup.
**Question 10.** Which instrument is used to measure superheat in a refrigeration system?
A) Psychrometer
B) Manifold gauge set with temperature probe
C) Anemometer
D) Multimeter
Answer: B
Explanation: A manifold gauge set with a temperature probe measures suction pressure and
temperature, allowing calculation of superheat.
**Question 11.** According to EPA Section 608, which type of refrigerant requires certification
for recovery, recycling, and reclamation?
A) Non‑ozone‑depleting refrigerants only
B) All refrigerants, including exempt small‑quantity devices
C) Only CFCs and HCFCs
D) Only HFCs above 50 lb
Answer: B
Explanation: Section 608 mandates certification for handling all refrigerants, regardless of ozone
depletion potential, except for certain exempt containers.
Certification Exam Preparation
**Question 1.** Which law explains the inverse relationship between pressure and volume of a
refrigerant at constant temperature?
A) Charles’s Law
B) Boyle’s Law
C) Dalton’s Law
D) Gay‑Lussac’s Law
Answer: B
Explanation: Boyle’s Law states that for a fixed amount of gas at constant temperature, pressure
and volume are inversely proportional (P × V = constant).
**Question 2.** In a refrigeration system, what type of heat transfer occurs when the
refrigerant vaporizes in the evaporator?
A) Sensible heat
B) Latent heat
C) Conduction heat
D) Radiant heat
Answer: B
Explanation: Vaporization absorbs latent heat from the refrigerated space, providing the cooling
effect without a temperature change of the refrigerant.
**Question 3.** Which component controls the flow of refrigerant into the evaporator based
on superheat?
A) Capillary tube
B) Thermostatic Expansion Valve (TXV)
C) Automatic Expansion Valve (AEV)
D) Receiver
Answer: B
, [HRC40] Hawaii Refrigeration Contractor C 40
Certification Exam Preparation
Explanation: A TXV meters refrigerant to maintain a set superheat, ensuring proper evaporation
and preventing liquid floodback to the compressor.
**Question 4.** What is the primary purpose of an accumulator in a low‑side system?
A) Increase refrigerant pressure
B) Remove oil from the suction line
C) Capture excess liquid refrigerant
D) Provide additional cooling capacity
Answer: C
Explanation: An accumulator collects and vaporizes any liquid refrigerant that may travel back
toward the compressor, protecting it from liquid slugging.
**Question 5.** Which refrigerant safety classification indicates a “low toxicity, low
flammability” fluid?
A) A1
B) A2L
C) B2
D) C3
Answer: B
Explanation: ASHRAE safety class A2L denotes refrigerants with low toxicity (A) and low
flammability (2L).
**Question 6.** When reading a pressure‑temperature (P‑T) chart for R‑410A, what does the
curve represent?
A) Enthalpy vs. temperature
B) Saturation pressure at various temperatures
C) Superheat values
, [HRC40] Hawaii Refrigeration Contractor C 40
Certification Exam Preparation
D) Subcooling limits
Answer: B
Explanation: The P‑T chart plots saturation pressure for corresponding saturation temperatures,
allowing determination of refrigerant state.
**Question 7.** In a walk‑in cooler, the most effective way to reduce heat gain through the
door is to use:
A) A thicker metal door
B) A double‑glazed door with low‑emissivity coating
C) A solid wood door
D) A single‑pane glass door
Answer: B
Explanation: Double‑glazed doors with low‑E coating provide high insulation values, minimizing
conductive and radiant heat transfer.
**Question 8.** Which type of condenser is most common in Hawaiian commercial
refrigeration due to limited water availability?
A) Water‑cooled condenser
B) Air‑cooled condenser
C) Evaporative condenser
D) Hybrid condenser
Answer: B
Explanation: Air‑cooled condensers avoid the need for a water source, making them suitable for
islands where water resources are limited.
**Question 9.** The purpose of a defrost timer in a mechanically‑controlled defrost system is
to:
, [HRC40] Hawaii Refrigeration Contractor C 40
Certification Exam Preparation
A) Measure the temperature of the evaporator coil
B) Initiate defrost cycles at preset intervals
C) Regulate compressor speed
D) Control suction line pressure
Answer: B
Explanation: A defrost timer starts a defrost cycle after a set operating time, ensuring periodic
removal of ice buildup.
**Question 10.** Which instrument is used to measure superheat in a refrigeration system?
A) Psychrometer
B) Manifold gauge set with temperature probe
C) Anemometer
D) Multimeter
Answer: B
Explanation: A manifold gauge set with a temperature probe measures suction pressure and
temperature, allowing calculation of superheat.
**Question 11.** According to EPA Section 608, which type of refrigerant requires certification
for recovery, recycling, and reclamation?
A) Non‑ozone‑depleting refrigerants only
B) All refrigerants, including exempt small‑quantity devices
C) Only CFCs and HCFCs
D) Only HFCs above 50 lb
Answer: B
Explanation: Section 608 mandates certification for handling all refrigerants, regardless of ozone
depletion potential, except for certain exempt containers.
