Page 1 of 128
HVAC CONTRACTOR EXAM UPDATE WITH
HIGHLY PREDICTED, CORRECT ANSWERS
AND MULTIPLE QUESTIONS |A+ GRADED|
1. According to IMC 2018, what is the minimum clearance from
a condensing unit to an operable window?
A) 1 foot
B) 3 feet
C) 6 feet
D) 10 feet
Answer: B) 3 feet
Rationale: IMC Section 1106.3 requires 3 ft to prevent exhaust
air re-entering the window and for service access.
2. A gas furnace installed in a garage must be elevated at
least ___ above the floor.
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A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Answer: C) 18 inches
Rationale: IFC/IMC require 18″ to avoid ignition of gasoline
vapors, which are heavier than air.
3. Which NFPA standard covers installation of air conditioning
and ventilating systems in one- and two-family dwellings?
A) NFPA 54
B) NFPA 70
C) NFPA 90B
D) NFPA 99
Answer: C) NFPA 90B
Rationale: NFPA 90B is for residential; NFPA 90A is for
commercial.
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4. The maximum allowable refrigerant leak rate per year for
an industrial process refrigeration system with 500 lbs charge
is:
A) 15%
B) 30%
C) 35%
D) 50%
Answer: C) 35%
Rationale: EPA 608 – industrial process refrigeration: 35% if >
500 lbs.
5. Scenario: You are servicing a rooftop unit. The electrical
disconnect is within sight but 60 feet away. OSHA requires
lockout/tagout if:
A) The distance is over 50 feet
B) The worker cannot see the energy isolation device
C) The unit has capacitors
D) Always required regardless
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Answer: B) The worker cannot see the energy isolation device
Rationale: OSHA 1910.147 – if not in sight and under control,
LOTO required.
6. What is the minimum combustion air opening size for a
100,000 BTU furnace in a confined space with two openings?
A) 50 sq in
B) 100 sq in
C) 150 sq in
D) 200 sq in
Answer: B) 100 sq in
Rationale: 1 sq in per 1,000 BTU for horizontal ducts; 1 per
1,000 for two openings.
7. According to the IMC, a condensate drain line must have a
trap if connected to a:
A) Condensate pump
B) Sanitary sewer
HVAC CONTRACTOR EXAM UPDATE WITH
HIGHLY PREDICTED, CORRECT ANSWERS
AND MULTIPLE QUESTIONS |A+ GRADED|
1. According to IMC 2018, what is the minimum clearance from
a condensing unit to an operable window?
A) 1 foot
B) 3 feet
C) 6 feet
D) 10 feet
Answer: B) 3 feet
Rationale: IMC Section 1106.3 requires 3 ft to prevent exhaust
air re-entering the window and for service access.
2. A gas furnace installed in a garage must be elevated at
least ___ above the floor.
,Page 2 of 128
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Answer: C) 18 inches
Rationale: IFC/IMC require 18″ to avoid ignition of gasoline
vapors, which are heavier than air.
3. Which NFPA standard covers installation of air conditioning
and ventilating systems in one- and two-family dwellings?
A) NFPA 54
B) NFPA 70
C) NFPA 90B
D) NFPA 99
Answer: C) NFPA 90B
Rationale: NFPA 90B is for residential; NFPA 90A is for
commercial.
,Page 3 of 128
4. The maximum allowable refrigerant leak rate per year for
an industrial process refrigeration system with 500 lbs charge
is:
A) 15%
B) 30%
C) 35%
D) 50%
Answer: C) 35%
Rationale: EPA 608 – industrial process refrigeration: 35% if >
500 lbs.
5. Scenario: You are servicing a rooftop unit. The electrical
disconnect is within sight but 60 feet away. OSHA requires
lockout/tagout if:
A) The distance is over 50 feet
B) The worker cannot see the energy isolation device
C) The unit has capacitors
D) Always required regardless
, Page 4 of 128
Answer: B) The worker cannot see the energy isolation device
Rationale: OSHA 1910.147 – if not in sight and under control,
LOTO required.
6. What is the minimum combustion air opening size for a
100,000 BTU furnace in a confined space with two openings?
A) 50 sq in
B) 100 sq in
C) 150 sq in
D) 200 sq in
Answer: B) 100 sq in
Rationale: 1 sq in per 1,000 BTU for horizontal ducts; 1 per
1,000 for two openings.
7. According to the IMC, a condensate drain line must have a
trap if connected to a:
A) Condensate pump
B) Sanitary sewer
