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Idaho Mechanical Plans Examiner
Examination Advanced 100-Question
Practice Exam 2026 | Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. During review of a commercial mechanical plan, the examiner finds that a
listed furnace is installed in a closet containing a return-air grille. The closet is
also used for storage of combustible materials. What is the primary plan-review
concern?
A. The furnace must be converted to electric heat
B. The return grille must be increased regardless of equipment size
C. The equipment installation must comply with required clearances,
combustion-air provisions, and restrictions on hazardous or combustible storage
D. The furnace must be located outdoors
Answer: C. The equipment installation must comply with required clearances,
combustion-air provisions, and restrictions on hazardous or combustible storage
Rationale: Plans examiners should evaluate the complete equipment
installation, including manufacturer clearances, combustion air, access, and the
potential hazards created by storage around fuel-burning equipment.
,2. A mechanical room contains a gas-fired appliance requiring combustion air
from indoors. Which factor is most important when determining whether
indoor combustion air is adequate?
A. The room's ceiling height only
B. The number of electrical receptacles
C. The available room volume and the aggregate input rating of fuel-burning
appliances
D. The number of supply-air diffusers
Answer: C. The available room volume and the aggregate input rating of fuel-
burning appliances
Rationale: Combustion-air methods are generally based on appliance input and
available space or specifically designed openings/ducts. The examiner must
verify that the selected method is permitted and properly sized.
3. A designer proposes a Type I commercial kitchen hood over cooking
equipment producing grease-laden vapors. What additional system must
normally be coordinated with the hood?
A. Residential dryer exhaust
B. A dedicated exhaust and makeup-air strategy appropriate for the hood
system
C. A bathroom exhaust fan only
D. A gravity furnace
Answer: B. A dedicated exhaust and makeup-air strategy appropriate for the
hood system
Rationale: Commercial cooking exhaust systems must be coordinated with
makeup air, hood construction, duct routing, fire protection, and building
pressure.
4. A duct passes through a rated fire-resistance-rated wall. Which plan-review
issue is most critical?
,A. Duct color
B. Duct insulation appearance
C. The required fire/smoke damper, shaft, penetration protection, or other
approved protection based on the assembly and duct function
D. The manufacturer's logo on the duct
Answer: C. The required fire/smoke damper, shaft, penetration protection, or
other approved protection based on the assembly and duct function
Rationale: Penetrations through rated assemblies must preserve the required
protection. Damper requirements depend on the rating, wall type, duct system,
and applicable code provisions.
5. A mechanical plan shows an outdoor-air intake immediately adjacent to a
plumbing vent termination. What should the examiner evaluate?
A. Only the diameter of the vent
B. Required separation between outdoor-air intakes and sources of
contamination
C. Whether the vent is painted
D. Whether the intake is located below the roof ridge
Answer: B. Required separation between outdoor-air intakes and sources of
contamination
Rationale: Outdoor-air intakes must be located to minimize contamination from
exhausts, vents, combustion products, and other pollutant sources.
6. A supply-air duct is shown penetrating a fire-resistance-rated corridor wall.
The plans do not identify a damper. What is the best plan-review response?
A. Approve because all ducts are automatically fire rated
B. Require the duct to be removed
C. Require the designer to demonstrate compliance with the applicable damper
or alternative protection requirements
D. Require the duct to be made from copper
, Answer: C. Require the designer to demonstrate compliance with the applicable
damper or alternative protection requirements
Rationale: A plans examiner should identify the missing protection and require
sufficient documentation to establish compliance rather than automatically
prescribing an inappropriate construction method.
7. A designer sizes a hydronic pump solely from the boiler manufacturer's
maximum flow rate. What additional information is necessary to properly
evaluate pump selection?
A. Paint color of the piping
B. Required system flow and total dynamic head, including piping and
component pressure losses
C. Number of thermostats
D. Ceiling finish
Answer: B. Required system flow and total dynamic head, including piping and
component pressure losses
Rationale: Pump selection depends on both flow and head. Pipe length, fittings,
valves, coils, boilers, heat exchangers, and other components contribute to
system resistance.
8. A mechanical plan identifies a relief valve but provides no discharge piping
information. What should the examiner verify?
A. The valve is painted red
B. The relief discharge arrangement complies with applicable safety and
discharge requirements
C. The valve is connected to the thermostat
D. The relief valve is installed on the return duct
Answer: B. The relief discharge arrangement complies with applicable safety
and discharge requirements
Idaho Mechanical Plans Examiner
Examination Advanced 100-Question
Practice Exam 2026 | Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. During review of a commercial mechanical plan, the examiner finds that a
listed furnace is installed in a closet containing a return-air grille. The closet is
also used for storage of combustible materials. What is the primary plan-review
concern?
A. The furnace must be converted to electric heat
B. The return grille must be increased regardless of equipment size
C. The equipment installation must comply with required clearances,
combustion-air provisions, and restrictions on hazardous or combustible storage
D. The furnace must be located outdoors
Answer: C. The equipment installation must comply with required clearances,
combustion-air provisions, and restrictions on hazardous or combustible storage
Rationale: Plans examiners should evaluate the complete equipment
installation, including manufacturer clearances, combustion air, access, and the
potential hazards created by storage around fuel-burning equipment.
,2. A mechanical room contains a gas-fired appliance requiring combustion air
from indoors. Which factor is most important when determining whether
indoor combustion air is adequate?
A. The room's ceiling height only
B. The number of electrical receptacles
C. The available room volume and the aggregate input rating of fuel-burning
appliances
D. The number of supply-air diffusers
Answer: C. The available room volume and the aggregate input rating of fuel-
burning appliances
Rationale: Combustion-air methods are generally based on appliance input and
available space or specifically designed openings/ducts. The examiner must
verify that the selected method is permitted and properly sized.
3. A designer proposes a Type I commercial kitchen hood over cooking
equipment producing grease-laden vapors. What additional system must
normally be coordinated with the hood?
A. Residential dryer exhaust
B. A dedicated exhaust and makeup-air strategy appropriate for the hood
system
C. A bathroom exhaust fan only
D. A gravity furnace
Answer: B. A dedicated exhaust and makeup-air strategy appropriate for the
hood system
Rationale: Commercial cooking exhaust systems must be coordinated with
makeup air, hood construction, duct routing, fire protection, and building
pressure.
4. A duct passes through a rated fire-resistance-rated wall. Which plan-review
issue is most critical?
,A. Duct color
B. Duct insulation appearance
C. The required fire/smoke damper, shaft, penetration protection, or other
approved protection based on the assembly and duct function
D. The manufacturer's logo on the duct
Answer: C. The required fire/smoke damper, shaft, penetration protection, or
other approved protection based on the assembly and duct function
Rationale: Penetrations through rated assemblies must preserve the required
protection. Damper requirements depend on the rating, wall type, duct system,
and applicable code provisions.
5. A mechanical plan shows an outdoor-air intake immediately adjacent to a
plumbing vent termination. What should the examiner evaluate?
A. Only the diameter of the vent
B. Required separation between outdoor-air intakes and sources of
contamination
C. Whether the vent is painted
D. Whether the intake is located below the roof ridge
Answer: B. Required separation between outdoor-air intakes and sources of
contamination
Rationale: Outdoor-air intakes must be located to minimize contamination from
exhausts, vents, combustion products, and other pollutant sources.
6. A supply-air duct is shown penetrating a fire-resistance-rated corridor wall.
The plans do not identify a damper. What is the best plan-review response?
A. Approve because all ducts are automatically fire rated
B. Require the duct to be removed
C. Require the designer to demonstrate compliance with the applicable damper
or alternative protection requirements
D. Require the duct to be made from copper
, Answer: C. Require the designer to demonstrate compliance with the applicable
damper or alternative protection requirements
Rationale: A plans examiner should identify the missing protection and require
sufficient documentation to establish compliance rather than automatically
prescribing an inappropriate construction method.
7. A designer sizes a hydronic pump solely from the boiler manufacturer's
maximum flow rate. What additional information is necessary to properly
evaluate pump selection?
A. Paint color of the piping
B. Required system flow and total dynamic head, including piping and
component pressure losses
C. Number of thermostats
D. Ceiling finish
Answer: B. Required system flow and total dynamic head, including piping and
component pressure losses
Rationale: Pump selection depends on both flow and head. Pipe length, fittings,
valves, coils, boilers, heat exchangers, and other components contribute to
system resistance.
8. A mechanical plan identifies a relief valve but provides no discharge piping
information. What should the examiner verify?
A. The valve is painted red
B. The relief discharge arrangement complies with applicable safety and
discharge requirements
C. The valve is connected to the thermostat
D. The relief valve is installed on the return duct
Answer: B. The relief discharge arrangement complies with applicable safety
and discharge requirements
