Idaho Air Conditioning Contractor
Qualification Advanced 100-Question
Practice Exam 2026 | Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. Which Idaho-adopted code is the primary code for mechanical installation
requirements for most commercial air-conditioning systems?
A. 2018 International Plumbing Code
B. 2018 International Mechanical Code
C. 2021 International Mechanical Code
D. 2018 National Electrical Code only
Answer: 2018 International Mechanical Code
Rationale: Idaho DOPL identifies the 2018 International Mechanical Code as one
of the current codes adopted for HVAC work. The mechanical code governs
many installation requirements for air-conditioning and mechanical systems.
2. An Idaho HVAC contractor performs work outside the scope permitted by the
contractor certificate. What is the principal licensing concern?
A. The work is automatically accepted if inspected
B. The work is permitted if the customer approves it
,C. The contractor may be subject to enforcement for performing work outside the
authorized scope
D. Only the equipment manufacturer can object
Answer: The contractor may be subject to enforcement for performing work
outside the authorized scope
Rationale: Idaho HVAC rules provide for civil penalties for performing HVAC
work without the required certificate or performing work outside the scope of a
specialty certificate.
3. What is the primary purpose of a Manual J residential load calculation?
A. Determine refrigerant type
B. Determine electrical conductor size
C. Determine heating and cooling loads
D. Determine duct leakage classification
Answer: Determine heating and cooling loads
Rationale: A load calculation estimates the building's heating and cooling
requirements and is used to properly size HVAC equipment rather than selecting
equipment solely from square footage.
4. A residential air conditioner has a calculated cooling load of 36,000 Btu/h.
Which nominal capacity is closest?
A. 1 ton
B. 2 tons
C. 3 tons
D. 5 tons
Answer: 3 tons
Rationale: One refrigeration ton is nominally 12,000 Btu/h. Therefore, 36,000 ÷
12,000 = 3 tons.
,5. A system is significantly oversized for the calculated cooling load. What is a
common consequence?
A. Longer continuous run times
B. Improved dehumidification under all conditions
C. Short cycling and reduced humidity control
D. Elimination of duct pressure losses
Answer: Short cycling and reduced humidity control
Rationale: Oversized equipment can satisfy sensible load rapidly and shut off
before adequately removing latent moisture, resulting in poor comfort and
potentially increased cycling.
6. What does sensible heat represent in an air-conditioning load?
A. Heat associated with moisture removal only
B. Heat that changes temperature without changing moisture content
C. Heat produced exclusively by compressors
D. Heat transferred only by radiation
Answer: Heat that changes temperature without changing moisture content
Rationale: Sensible heat changes dry-bulb temperature. Latent heat is
associated with moisture changes such as condensation or evaporation.
7. What is latent cooling primarily associated with?
A. Reduction of air temperature only
B. Removal of moisture from air
C. Compressor motor cooling
D. Refrigerant pressure increase
Answer: Removal of moisture from air
Rationale: When moist air is cooled below its dew point, water vapor condenses
on the evaporator coil. The associated energy removal is latent cooling.
, 8. What happens to refrigerant pressure when a typical vapor-compression
compressor raises refrigerant vapor from the suction side to the discharge side?
A. It decreases substantially
B. It remains exactly constant
C. It increases substantially
D. It becomes atmospheric
Answer: It increases substantially
Rationale: The compressor raises the pressure and temperature of the
refrigerant vapor so it can reject heat in the condenser.
9. What is the primary function of an evaporator coil in an air-conditioning
system?
A. Reject heat to outdoor air
B. Absorb heat from the conditioned space or air stream
C. Increase refrigerant pressure
D. Store liquid refrigerant permanently
Answer: Absorb heat from the conditioned space or air stream
Rationale: The evaporator is the low-side heat exchanger where refrigerant
absorbs heat while changing state from liquid or liquid-vapor mixture toward
vapor.
10. What is the primary function of the condenser?
A. Absorb indoor heat
B. Reject heat from the refrigerant to the surrounding medium
C. Lower compressor discharge pressure
D. Meter refrigerant into the evaporator
Answer: Reject heat from the refrigerant to the surrounding medium
Qualification Advanced 100-Question
Practice Exam 2026 | Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. Which Idaho-adopted code is the primary code for mechanical installation
requirements for most commercial air-conditioning systems?
A. 2018 International Plumbing Code
B. 2018 International Mechanical Code
C. 2021 International Mechanical Code
D. 2018 National Electrical Code only
Answer: 2018 International Mechanical Code
Rationale: Idaho DOPL identifies the 2018 International Mechanical Code as one
of the current codes adopted for HVAC work. The mechanical code governs
many installation requirements for air-conditioning and mechanical systems.
2. An Idaho HVAC contractor performs work outside the scope permitted by the
contractor certificate. What is the principal licensing concern?
A. The work is automatically accepted if inspected
B. The work is permitted if the customer approves it
,C. The contractor may be subject to enforcement for performing work outside the
authorized scope
D. Only the equipment manufacturer can object
Answer: The contractor may be subject to enforcement for performing work
outside the authorized scope
Rationale: Idaho HVAC rules provide for civil penalties for performing HVAC
work without the required certificate or performing work outside the scope of a
specialty certificate.
3. What is the primary purpose of a Manual J residential load calculation?
A. Determine refrigerant type
B. Determine electrical conductor size
C. Determine heating and cooling loads
D. Determine duct leakage classification
Answer: Determine heating and cooling loads
Rationale: A load calculation estimates the building's heating and cooling
requirements and is used to properly size HVAC equipment rather than selecting
equipment solely from square footage.
4. A residential air conditioner has a calculated cooling load of 36,000 Btu/h.
Which nominal capacity is closest?
A. 1 ton
B. 2 tons
C. 3 tons
D. 5 tons
Answer: 3 tons
Rationale: One refrigeration ton is nominally 12,000 Btu/h. Therefore, 36,000 ÷
12,000 = 3 tons.
,5. A system is significantly oversized for the calculated cooling load. What is a
common consequence?
A. Longer continuous run times
B. Improved dehumidification under all conditions
C. Short cycling and reduced humidity control
D. Elimination of duct pressure losses
Answer: Short cycling and reduced humidity control
Rationale: Oversized equipment can satisfy sensible load rapidly and shut off
before adequately removing latent moisture, resulting in poor comfort and
potentially increased cycling.
6. What does sensible heat represent in an air-conditioning load?
A. Heat associated with moisture removal only
B. Heat that changes temperature without changing moisture content
C. Heat produced exclusively by compressors
D. Heat transferred only by radiation
Answer: Heat that changes temperature without changing moisture content
Rationale: Sensible heat changes dry-bulb temperature. Latent heat is
associated with moisture changes such as condensation or evaporation.
7. What is latent cooling primarily associated with?
A. Reduction of air temperature only
B. Removal of moisture from air
C. Compressor motor cooling
D. Refrigerant pressure increase
Answer: Removal of moisture from air
Rationale: When moist air is cooled below its dew point, water vapor condenses
on the evaporator coil. The associated energy removal is latent cooling.
, 8. What happens to refrigerant pressure when a typical vapor-compression
compressor raises refrigerant vapor from the suction side to the discharge side?
A. It decreases substantially
B. It remains exactly constant
C. It increases substantially
D. It becomes atmospheric
Answer: It increases substantially
Rationale: The compressor raises the pressure and temperature of the
refrigerant vapor so it can reject heat in the condenser.
9. What is the primary function of an evaporator coil in an air-conditioning
system?
A. Reject heat to outdoor air
B. Absorb heat from the conditioned space or air stream
C. Increase refrigerant pressure
D. Store liquid refrigerant permanently
Answer: Absorb heat from the conditioned space or air stream
Rationale: The evaporator is the low-side heat exchanger where refrigerant
absorbs heat while changing state from liquid or liquid-vapor mixture toward
vapor.
10. What is the primary function of the condenser?
A. Absorb indoor heat
B. Reject heat from the refrigerant to the surrounding medium
C. Lower compressor discharge pressure
D. Meter refrigerant into the evaporator
Answer: Reject heat from the refrigerant to the surrounding medium
