LATEST Residential Mechanical Inspector
(M1) CERTIFICATION EXAM OFFERED BY
INTERNATIONAL CODE COUNCIL (ICC) |
Q&A WITH RATIONALES
1. A gas-fired furnace is installed in an attic. The attic
access opening must have a minimum clear opening
of:
A) 20 inches by 24 inches
B) 22 inches by 30 inches
C) 24 inches by 36 inches
D) 30 inches by 30 inches
Correct answer: B
Rationale: IRC M1305.1.3 requires attic access
openings for equipment to be at least 22 inches by 30
inches.
2. A 40,000 Btu/hr gas furnace is located in a
basement. The basement volume is 1,200 cubic feet.
The house has an additional 8,000 cubic feet of
conditioned space. Is the basement considered an
unconfined space?
,A) Yes, total volume is 9,200 cubic feet, which
exceeds 50 cubic feet per 1,000 Btu/hr
B) No, only the basement volume is considered,
which is insufficient
C) Yes, if the basement has a door to the upper floors
D) No, the furnace requires a dedicated combustion
air duct
Correct answer: A
Rationale: The total volume of all communicating
spaces is used to determine if the space is
unconfined. 40,000 Btu/hr requires 2,000 cubic feet
(50 × 40). 9,200 cubic feet is well above that.
3. A 50,000 Btu/hr furnace is installed in a closet. The
closet has two combustion air openings, one within
12 inches of the ceiling and one within 12 inches of
the floor. Each opening must have a minimum free
area of:
A) 50 sq in
B) 100 sq in
C) 150 sq in
D) 200 sq in
Correct answer: A
,Rationale: For combustion air from inside the
building, each opening must have a free area of at
least 1 sq in per 1,000 Btu/hr of total input. 50,000
Btu/hr requires 50 sq in per opening.
4. A gas water heater is installed in a garage. The
water heater must be elevated so that the pilot light
or burner is at least how many inches above the
garage floor?
A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
Correct answer: B
Rationale: IRC M1305.1.3.2 requires ignition sources
in garages to be at least 18 inches above the floor.
5. A 100,000 Btu/hr gas furnace is installed in a
mechanical room. The room is 10 feet by 10 feet with
an 8-foot ceiling. Is this an unconfined space?
A) Yes, the volume is 800 cubic feet, which is less
than 50 cubic feet per 1,000 Btu/hr (5,000 cubic feet
required)
, B) No, the volume is insufficient; additional
combustion air must be provided
C) Yes, if the room has a louvered door
D) No, the furnace requires a dedicated outdoor air
supply
Correct answer: B
Rationale: 100,000 Btu/hr requires 5,000 cubic feet
for unconfined space. 800 cubic feet is far less.
Combustion air openings are required.
6. A gas furnace is installed in a crawl space. The
crawl space must have a minimum access opening
of:
A) 18 inches by 24 inches
B) 22 inches by 30 inches
C) 24 inches by 36 inches
D) 30 inches by 30 inches
Correct answer: A
Rationale: IRC M1305.1.4 requires crawl space
access openings for equipment to be at least 18
inches by 24 inches.
(M1) CERTIFICATION EXAM OFFERED BY
INTERNATIONAL CODE COUNCIL (ICC) |
Q&A WITH RATIONALES
1. A gas-fired furnace is installed in an attic. The attic
access opening must have a minimum clear opening
of:
A) 20 inches by 24 inches
B) 22 inches by 30 inches
C) 24 inches by 36 inches
D) 30 inches by 30 inches
Correct answer: B
Rationale: IRC M1305.1.3 requires attic access
openings for equipment to be at least 22 inches by 30
inches.
2. A 40,000 Btu/hr gas furnace is located in a
basement. The basement volume is 1,200 cubic feet.
The house has an additional 8,000 cubic feet of
conditioned space. Is the basement considered an
unconfined space?
,A) Yes, total volume is 9,200 cubic feet, which
exceeds 50 cubic feet per 1,000 Btu/hr
B) No, only the basement volume is considered,
which is insufficient
C) Yes, if the basement has a door to the upper floors
D) No, the furnace requires a dedicated combustion
air duct
Correct answer: A
Rationale: The total volume of all communicating
spaces is used to determine if the space is
unconfined. 40,000 Btu/hr requires 2,000 cubic feet
(50 × 40). 9,200 cubic feet is well above that.
3. A 50,000 Btu/hr furnace is installed in a closet. The
closet has two combustion air openings, one within
12 inches of the ceiling and one within 12 inches of
the floor. Each opening must have a minimum free
area of:
A) 50 sq in
B) 100 sq in
C) 150 sq in
D) 200 sq in
Correct answer: A
,Rationale: For combustion air from inside the
building, each opening must have a free area of at
least 1 sq in per 1,000 Btu/hr of total input. 50,000
Btu/hr requires 50 sq in per opening.
4. A gas water heater is installed in a garage. The
water heater must be elevated so that the pilot light
or burner is at least how many inches above the
garage floor?
A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
Correct answer: B
Rationale: IRC M1305.1.3.2 requires ignition sources
in garages to be at least 18 inches above the floor.
5. A 100,000 Btu/hr gas furnace is installed in a
mechanical room. The room is 10 feet by 10 feet with
an 8-foot ceiling. Is this an unconfined space?
A) Yes, the volume is 800 cubic feet, which is less
than 50 cubic feet per 1,000 Btu/hr (5,000 cubic feet
required)
, B) No, the volume is insufficient; additional
combustion air must be provided
C) Yes, if the room has a louvered door
D) No, the furnace requires a dedicated outdoor air
supply
Correct answer: B
Rationale: 100,000 Btu/hr requires 5,000 cubic feet
for unconfined space. 800 cubic feet is far less.
Combustion air openings are required.
6. A gas furnace is installed in a crawl space. The
crawl space must have a minimum access opening
of:
A) 18 inches by 24 inches
B) 22 inches by 30 inches
C) 24 inches by 36 inches
D) 30 inches by 30 inches
Correct answer: A
Rationale: IRC M1305.1.4 requires crawl space
access openings for equipment to be at least 18
inches by 24 inches.
