ALABAMA HVAC CONTRACTOR LICENSING
EXAM 100 QUESTIONS WITH CORRECT
ANSWERS AND RATIONALES LATEST 2025-2026
UPDATE
1. Which of the following codes governs HVAC installation in
Alabama?
A) NFPA 70
B) International Mechanical Code (IMC)
C) Alabama Building Code
D) All of the above
Answer: D) All of the above
Rationale: HVAC contractors in Alabama must follow the Alabama
Building Code, which incorporates the IMC, and NFPA 70 for electrical
safety.
2. The minimum refrigerant charge for a system is determined by:
A) Manufacturer’s specifications
B) IMC guidelines
C) Contractor’s experience
D) Local climate
,Answer: A) Manufacturer’s specifications
Rationale: Refrigerant charge must follow the manufacturer’s data plate
to ensure system efficiency and avoid damage.
3. Which type of refrigerant is most commonly used in modern
residential systems?
A) R-22
B) R-410A
C) R-134a
D) Ammonia
Answer: B) R-410A
Rationale: R-410A has replaced R-22 in most new systems due to
environmental regulations banning R-22 production.
4. In Alabama, a licensed HVAC contractor must maintain:
A) Insurance
B) Bonding
C) Continuing education
D) All of the above
Answer: D) All of the above
Rationale: Contractors must have liability insurance, surety bonding,
and complete continuing education for license renewal.
5. The primary purpose of a condensate drain is to:
A) Remove excess refrigerant
B) Drain water from the evaporator coil
,C) Equalize pressure
D) Vent gases
Answer: B) Drain water from the evaporator coil
Rationale: During cooling, water condenses on the coil; the drain line
removes this moisture to prevent water damage.
6. What is the maximum temperature a residential gas furnace flue
should reach at the vent?
A) 150°F
B) 250°F
C) 350°F
D) 450°F
Answer: D) 450°F
Rationale: Most residential gas furnace vents are designed to operate
safely below 450°F to prevent fire hazards.
7. Which electrical wiring is commonly used in residential HVAC
systems in Alabama?
A) THHN
B) NM-B (Romex)
C) MC Cable
D) All of the above
Answer: D) All of the above
Rationale: THHN is used in conduit, NM-B for dry walls, and MC
cable in commercial applications; all may appear in HVAC installations.
, 8. What is the minimum clearance for combustion air intake near a
gas furnace?
A) 6 inches
B) 12 inches
C) 24 inches
D) 36 inches
Answer: B) 12 inches
Rationale: The IMC requires at least 12 inches clearance to ensure safe
air supply for combustion.
9. SEER stands for:
A) Standard Energy Efficiency Rating
B) Seasonal Energy Efficiency Ratio
C) System Efficiency Electrical Rating
D) Safety Energy Electrical Ratio
Answer: B) Seasonal Energy Efficiency Ratio
Rationale: SEER measures cooling efficiency of HVAC systems over a
season; higher SEER = more efficiency.
10. When installing a duct system, the minimum insulation in
Alabama for residential supply ducts in unconditioned spaces is:
A) R-4
B) R-6
C) R-8
D) R-10
EXAM 100 QUESTIONS WITH CORRECT
ANSWERS AND RATIONALES LATEST 2025-2026
UPDATE
1. Which of the following codes governs HVAC installation in
Alabama?
A) NFPA 70
B) International Mechanical Code (IMC)
C) Alabama Building Code
D) All of the above
Answer: D) All of the above
Rationale: HVAC contractors in Alabama must follow the Alabama
Building Code, which incorporates the IMC, and NFPA 70 for electrical
safety.
2. The minimum refrigerant charge for a system is determined by:
A) Manufacturer’s specifications
B) IMC guidelines
C) Contractor’s experience
D) Local climate
,Answer: A) Manufacturer’s specifications
Rationale: Refrigerant charge must follow the manufacturer’s data plate
to ensure system efficiency and avoid damage.
3. Which type of refrigerant is most commonly used in modern
residential systems?
A) R-22
B) R-410A
C) R-134a
D) Ammonia
Answer: B) R-410A
Rationale: R-410A has replaced R-22 in most new systems due to
environmental regulations banning R-22 production.
4. In Alabama, a licensed HVAC contractor must maintain:
A) Insurance
B) Bonding
C) Continuing education
D) All of the above
Answer: D) All of the above
Rationale: Contractors must have liability insurance, surety bonding,
and complete continuing education for license renewal.
5. The primary purpose of a condensate drain is to:
A) Remove excess refrigerant
B) Drain water from the evaporator coil
,C) Equalize pressure
D) Vent gases
Answer: B) Drain water from the evaporator coil
Rationale: During cooling, water condenses on the coil; the drain line
removes this moisture to prevent water damage.
6. What is the maximum temperature a residential gas furnace flue
should reach at the vent?
A) 150°F
B) 250°F
C) 350°F
D) 450°F
Answer: D) 450°F
Rationale: Most residential gas furnace vents are designed to operate
safely below 450°F to prevent fire hazards.
7. Which electrical wiring is commonly used in residential HVAC
systems in Alabama?
A) THHN
B) NM-B (Romex)
C) MC Cable
D) All of the above
Answer: D) All of the above
Rationale: THHN is used in conduit, NM-B for dry walls, and MC
cable in commercial applications; all may appear in HVAC installations.
, 8. What is the minimum clearance for combustion air intake near a
gas furnace?
A) 6 inches
B) 12 inches
C) 24 inches
D) 36 inches
Answer: B) 12 inches
Rationale: The IMC requires at least 12 inches clearance to ensure safe
air supply for combustion.
9. SEER stands for:
A) Standard Energy Efficiency Rating
B) Seasonal Energy Efficiency Ratio
C) System Efficiency Electrical Rating
D) Safety Energy Electrical Ratio
Answer: B) Seasonal Energy Efficiency Ratio
Rationale: SEER measures cooling efficiency of HVAC systems over a
season; higher SEER = more efficiency.
10. When installing a duct system, the minimum insulation in
Alabama for residential supply ducts in unconditioned spaces is:
A) R-4
B) R-6
C) R-8
D) R-10
