Page 1 of 152
Master Mechanical – G29-N Contractor Exam
QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES
Master Mechanical – G29-N Contractor Exam
10 MOST-TESTED EXAM COVERAGE AREAS
10 MOST-TESTED EXAM COVERAGE AREAS
1. General Mechanical Code Requirements and Administration — Scope, definitions, permits,
inspections, approved materials, equipment installation, manufacturer's instructions,
accessibility, identification, clearances, protection, and general code requirements.
2. Appliances and Mechanical Equipment — Furnaces, boilers, water heaters, cooling equipment,
rooftop equipment, appliances, installation locations, clearances, service access, supports,
protection, controls, and equipment connections.
3. Combustion Air and Ventilation — Required combustion air, openings, indoor and outdoor air
methods, mechanical combustion-air systems, confined spaces, communicating spaces, and
preventing unsafe combustion.
4. Chimneys, Vents and Exhaust Systems — Vent connectors, chimneys, Type B vents, appliance
venting, draft, termination, clearances, material requirements, condensate, and protection
against unsafe vent operation.
5. Duct Systems and Air Distribution — Supply and return ducts, materials, joints, supports,
dampers, insulation, plenums, fire and smoke protection, duct penetrations, flexible ducts, and
air distribution.
6. Heating, Ventilation and Air-Conditioning Systems — Heating and cooling equipment, air-
handling units, refrigeration-related equipment, condensate disposal, evaporative cooling,
ventilation systems, filters, outdoor air, and system installation.
7. Fuel-Gas Systems and Piping — Natural gas and LP-gas piping, pipe sizing, pressure, regulators,
shutoff valves, appliance connections, testing, leak protection, gas vents, combustion
requirements, and gas-fired equipment.
8. Boilers, Hydronic and Steam Systems — Boilers, hot-water systems, steam systems, piping,
pumps, expansion tanks, safety controls, pressure relief, temperature controls, circulation, and
system protection.
9. Refrigeration and Cooling Systems — Refrigerants, compressors, condensers, evaporators,
piping, pressure controls, refrigerant safety, equipment rooms, leak considerations, recovery
requirements, and service practices.
10. Safety, Energy Efficiency, Installation Practice and Troubleshooting — Electrical/mechanical
safety, lockout/tagout, emergency controls, energy conservation, equipment efficiency,
maintenance access, system diagnosis, and code-compliant corrective work.
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Question 1
A mechanical contractor begins installing new commercial equipment before obtaining the required
permit from the authority having jurisdiction. What is the main problem?
A. The equipment is too large
B. The work may violate permit requirements
C. The equipment needs more insulation
D. The contractor must replace the ductwork
Answer: B
Rationale: Required mechanical work generally must be properly permitted before installation begins,
subject to applicable exceptions.
Question 2
A technician installs mechanical equipment using a method that conflicts with the manufacturer's listed
installation instructions. Which requirement should receive careful attention?
A. The manufacturer's installation instructions
B. The contractor's preferred method
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C. The building owner's preference
D. The equipment sales receipt
Answer: A
Rationale: Listed equipment should be installed according to its listing and manufacturer's installation
instructions where required by code.
Question 3
A furnace is installed inside a small enclosed room with limited openings for outside air. What condition
should the contractor evaluate first?
A. Paint color
B. Combustion-air requirements
C. Floor covering
D. Thermostat location only
Answer: B
Rationale: Fuel-burning equipment needs adequate combustion air for safe and complete combustion.
Question 4
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A mechanical room contains a fuel-burning appliance and has very limited volume. Why is room volume
important when checking combustion air?
A. Room volume can affect the available combustion air
B. Room volume determines the thermostat voltage
C. Room volume controls refrigerant pressure
D. Room volume determines pipe insulation thickness
Answer: A
Rationale: The available room volume can affect whether additional combustion-air openings are
required.
Question 5
A contractor installs a gas-fired appliance without providing the required accessible gas shutoff valve.
What is the primary concern?
A. The appliance will cool too quickly
B. The appliance cannot be safely isolated
C. The duct system becomes oversized
D. The thermostat becomes inaccurate
Master Mechanical – G29-N Contractor Exam
QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES
Master Mechanical – G29-N Contractor Exam
10 MOST-TESTED EXAM COVERAGE AREAS
10 MOST-TESTED EXAM COVERAGE AREAS
1. General Mechanical Code Requirements and Administration — Scope, definitions, permits,
inspections, approved materials, equipment installation, manufacturer's instructions,
accessibility, identification, clearances, protection, and general code requirements.
2. Appliances and Mechanical Equipment — Furnaces, boilers, water heaters, cooling equipment,
rooftop equipment, appliances, installation locations, clearances, service access, supports,
protection, controls, and equipment connections.
3. Combustion Air and Ventilation — Required combustion air, openings, indoor and outdoor air
methods, mechanical combustion-air systems, confined spaces, communicating spaces, and
preventing unsafe combustion.
4. Chimneys, Vents and Exhaust Systems — Vent connectors, chimneys, Type B vents, appliance
venting, draft, termination, clearances, material requirements, condensate, and protection
against unsafe vent operation.
5. Duct Systems and Air Distribution — Supply and return ducts, materials, joints, supports,
dampers, insulation, plenums, fire and smoke protection, duct penetrations, flexible ducts, and
air distribution.
6. Heating, Ventilation and Air-Conditioning Systems — Heating and cooling equipment, air-
handling units, refrigeration-related equipment, condensate disposal, evaporative cooling,
ventilation systems, filters, outdoor air, and system installation.
7. Fuel-Gas Systems and Piping — Natural gas and LP-gas piping, pipe sizing, pressure, regulators,
shutoff valves, appliance connections, testing, leak protection, gas vents, combustion
requirements, and gas-fired equipment.
8. Boilers, Hydronic and Steam Systems — Boilers, hot-water systems, steam systems, piping,
pumps, expansion tanks, safety controls, pressure relief, temperature controls, circulation, and
system protection.
9. Refrigeration and Cooling Systems — Refrigerants, compressors, condensers, evaporators,
piping, pressure controls, refrigerant safety, equipment rooms, leak considerations, recovery
requirements, and service practices.
10. Safety, Energy Efficiency, Installation Practice and Troubleshooting — Electrical/mechanical
safety, lockout/tagout, emergency controls, energy conservation, equipment efficiency,
maintenance access, system diagnosis, and code-compliant corrective work.
, Page 2 of 152
Question 1
A mechanical contractor begins installing new commercial equipment before obtaining the required
permit from the authority having jurisdiction. What is the main problem?
A. The equipment is too large
B. The work may violate permit requirements
C. The equipment needs more insulation
D. The contractor must replace the ductwork
Answer: B
Rationale: Required mechanical work generally must be properly permitted before installation begins,
subject to applicable exceptions.
Question 2
A technician installs mechanical equipment using a method that conflicts with the manufacturer's listed
installation instructions. Which requirement should receive careful attention?
A. The manufacturer's installation instructions
B. The contractor's preferred method
, Page 3 of 152
C. The building owner's preference
D. The equipment sales receipt
Answer: A
Rationale: Listed equipment should be installed according to its listing and manufacturer's installation
instructions where required by code.
Question 3
A furnace is installed inside a small enclosed room with limited openings for outside air. What condition
should the contractor evaluate first?
A. Paint color
B. Combustion-air requirements
C. Floor covering
D. Thermostat location only
Answer: B
Rationale: Fuel-burning equipment needs adequate combustion air for safe and complete combustion.
Question 4
, Page 4 of 152
A mechanical room contains a fuel-burning appliance and has very limited volume. Why is room volume
important when checking combustion air?
A. Room volume can affect the available combustion air
B. Room volume determines the thermostat voltage
C. Room volume controls refrigerant pressure
D. Room volume determines pipe insulation thickness
Answer: A
Rationale: The available room volume can affect whether additional combustion-air openings are
required.
Question 5
A contractor installs a gas-fired appliance without providing the required accessible gas shutoff valve.
What is the primary concern?
A. The appliance will cool too quickly
B. The appliance cannot be safely isolated
C. The duct system becomes oversized
D. The thermostat becomes inaccurate
