Arizona HVAC Contractor Exam Verified
Questions, Correct Answers, and Detailed
Explanations for Science Students||Already
Graded A+
1. Which refrigerant is considered an ozone-depleting substance
under current EPA regulations?
A. R-410A
B. R-22
C. R-134a
D. R-32
R-22 is a hydrochlorofluorocarbon (HCFC) that contributes to ozone
depletion. Its production has been phased out in many countries.
2. What is the minimum clearance required around a furnace for
proper service access?
A. 6 inches
B. 12 inches
C. 18 inches
D. 30 inches
Most codes, including the Arizona Mechanical Code, require at least
30 inches of clearance for safe access.
3. What device prevents backflow of water into a potable water
supply in HVAC systems?
A. Pressure relief valve
B. Expansion tank
C. Backflow preventer
D. Check valve
A backflow preventer is specifically designed to stop contaminated
water from flowing back into clean water lines.
4. Which type of duct material is most commonly used for
residential forced-air HVAC systems?
,A. PVC
B. Copper
C. Galvanized steel
D. Aluminum tubing
Galvanized steel is durable, resistant to corrosion, and widely used in
residential ductwork.
5. In Arizona, HVAC contractors must be licensed by which state
agency?
A. Arizona Department of Health Services
B. Arizona Utilities Commission
C. Arizona Registrar of Contractors (ROC)
D. Arizona Building Authority
The ROC regulates licensing for contractors, including HVAC
professionals.
6. What is the primary purpose of a furnace limit switch?
A. To control airflow
B. To detect gas leaks
C. To prevent overheating of the furnace
D. To ignite the burners
The limit switch shuts down the furnace if temperatures exceed safe
levels, preventing fire or equipment damage.
7. Which type of expansion valve is commonly used in modern
residential AC systems?
A. Float valve
B. Capillary tube
C. Thermostatic expansion valve (TXV)
D. Manual needle valve
TXVs control the flow of refrigerant to the evaporator based on
temperature, improving efficiency.
8. What is the standard electrical voltage for most residential HVAC
systems in the U.S.?
, A. 120/208 V
B. 120/240 V
C. 240/480 V
D. 277/480 V
Residential HVAC systems typically operate on 120/240 V single-
phase power.
9. What is the purpose of a condensate pump in an air conditioning
system?
A. Increase refrigerant flow
B. Remove heat from coils
C. Pump water from the condensate pan to a drain
D. Regulate airflow
The condensate pump prevents water from accumulating in the pan
and causing water damage.
10. What is the minimum SEER rating for new central air
conditioners in Arizona as of current regulations?
A. 10
B. 12
C. 13
D. 14
New units installed in Arizona must meet at least 14 SEER for energy
efficiency compliance.
11. Which gas is commonly used to test for refrigerant leaks?
A. Oxygen
B. Nitrogen
C. Nitrogen with trace gas (like helium or HFC tracer)
D. Carbon dioxide
Nitrogen with a trace gas is used to pressurize systems and detect
leaks safely.
12. What is the function of a reversing valve in a heat pump
system?
Questions, Correct Answers, and Detailed
Explanations for Science Students||Already
Graded A+
1. Which refrigerant is considered an ozone-depleting substance
under current EPA regulations?
A. R-410A
B. R-22
C. R-134a
D. R-32
R-22 is a hydrochlorofluorocarbon (HCFC) that contributes to ozone
depletion. Its production has been phased out in many countries.
2. What is the minimum clearance required around a furnace for
proper service access?
A. 6 inches
B. 12 inches
C. 18 inches
D. 30 inches
Most codes, including the Arizona Mechanical Code, require at least
30 inches of clearance for safe access.
3. What device prevents backflow of water into a potable water
supply in HVAC systems?
A. Pressure relief valve
B. Expansion tank
C. Backflow preventer
D. Check valve
A backflow preventer is specifically designed to stop contaminated
water from flowing back into clean water lines.
4. Which type of duct material is most commonly used for
residential forced-air HVAC systems?
,A. PVC
B. Copper
C. Galvanized steel
D. Aluminum tubing
Galvanized steel is durable, resistant to corrosion, and widely used in
residential ductwork.
5. In Arizona, HVAC contractors must be licensed by which state
agency?
A. Arizona Department of Health Services
B. Arizona Utilities Commission
C. Arizona Registrar of Contractors (ROC)
D. Arizona Building Authority
The ROC regulates licensing for contractors, including HVAC
professionals.
6. What is the primary purpose of a furnace limit switch?
A. To control airflow
B. To detect gas leaks
C. To prevent overheating of the furnace
D. To ignite the burners
The limit switch shuts down the furnace if temperatures exceed safe
levels, preventing fire or equipment damage.
7. Which type of expansion valve is commonly used in modern
residential AC systems?
A. Float valve
B. Capillary tube
C. Thermostatic expansion valve (TXV)
D. Manual needle valve
TXVs control the flow of refrigerant to the evaporator based on
temperature, improving efficiency.
8. What is the standard electrical voltage for most residential HVAC
systems in the U.S.?
, A. 120/208 V
B. 120/240 V
C. 240/480 V
D. 277/480 V
Residential HVAC systems typically operate on 120/240 V single-
phase power.
9. What is the purpose of a condensate pump in an air conditioning
system?
A. Increase refrigerant flow
B. Remove heat from coils
C. Pump water from the condensate pan to a drain
D. Regulate airflow
The condensate pump prevents water from accumulating in the pan
and causing water damage.
10. What is the minimum SEER rating for new central air
conditioners in Arizona as of current regulations?
A. 10
B. 12
C. 13
D. 14
New units installed in Arizona must meet at least 14 SEER for energy
efficiency compliance.
11. Which gas is commonly used to test for refrigerant leaks?
A. Oxygen
B. Nitrogen
C. Nitrogen with trace gas (like helium or HFC tracer)
D. Carbon dioxide
Nitrogen with a trace gas is used to pressurize systems and detect
leaks safely.
12. What is the function of a reversing valve in a heat pump
system?
