Louisiana 640-LA Second Class Stationary Air
Conditioning Exam
Complete Practice Exam (100+ Questions)
Which of the following best describes "sensible heat" in an air conditioning context?
A) The heat required to change water to vapor
B) The heat associated with a change in temperature of a substance without a phase change
C) The heat associated with moisture in the air
D) The heat required to cool the refrigerant below saturation temperature
Correct Answer: B
Explanation: Sensible heat changes the temperature of a substance. Latent heat changes the
state (phase).
2. In the context of air conditioning, "latent heat" refers to:
A) Heat that directly raises the temperature of a substance
B) Heat required to induce a phase change without a temperature change
C) Additional heat from solar radiation
D) Heat lost through uninsulated ducts
Correct Answer: B
Explanation: Latent heat is the energy absorbed or released during a phase change (e.g., liquid to vapor)
at a constant temperature.
3. According to basic thermodynamic principles, heat naturally flows:
A) From cold objects to warmer objects
B) From warm objects to colder objects
C) Randomly in all directions
D) Only if driven by a compressor
Correct Answer: B
Explanation: The second law of thermodynamics states that heat flows from a region of higher
temperature to a region of lower temperature.
,4. The term "BTU" stands for:
A) British Thermal Unit
B) Boiler Temperature Unit
C) Basic Temperature Utility
D) Burn Time Unit
Correct Answer: A
Explanation: One BTU is the amount of heat needed to raise the temperature of one pound of water by
1°F.
5. In HVAC terminology, "ASHRAE" stands for:
A) American Society of Heating, Refrigerating and Air-Conditioning Engineers
B) Association of Systemic Heating and Refrigeration Engineers
C) American Service for Heat and Refrigeration Evaluation
D) Accredited Society of Home Air Regulation Experts
Correct Answer: A
Explanation: ASHRAE is the global standards-setting organization for HVAC/R.
6. The psychrometric chart is primarily used to analyze:
A) Electrical conductivity of refrigerants
B) Relationship between air temperature, moisture, and enthalpy
C) Efficiency of compressors in varying pressures
D) Fan performance curves
Correct Answer: B
Explanation: The psychrometric chart plots the properties of air, including dry-bulb temperature, wet-
bulb temperature, humidity, and enthalpy.
7. The primary goal of an air conditioning system is to:
A) Provide mechanical ventilation only
B) Control temperature, humidity, and indoor air quality
C) Refrigerate food products in large warehouses
D) Increase ambient noise for better acoustics
Correct Answer: B
, Explanation: Air conditioning is defined as the process of treating air to control its temperature,
humidity, cleanliness, and distribution.
8. Which of the following codes commonly governs HVAC installations in Louisiana?
A) International Mechanical Code (IMC)
B) Uniform Building Code (UBC)
C) National Electrical Code (NEC) – (While used, the question asks specifically for HVAC)
D) Federal Exhaust Standards (FES)
Correct Answer: A
Explanation: The International Mechanical Code (IMC) is widely adopted in Louisiana for HVAC
installations.
9. When referring to air conditioning loads, which of the following is considered an internal load?
A) Solar heat gain through windows
B) Heat gain from occupants and appliances
C) Heat loss through exterior walls
D) Infiltration from outside air
Correct Answer: B
Explanation: Internal loads are generated inside the conditioned space, such as people, lights, and
equipment.
10. In Louisiana, local amendments to the IMC may require additional considerations for:
A) Seismic anchoring
B) Flood protection and elevated equipment platforms
C) High-altitude condenser sizing
D) Sub-zero pipe insulation
Correct Answer: B
Explanation: Due to the high risk of flooding in New Orleans and Louisiana, mechanical equipment often
requires flood-proofing or elevation.
Section 2: Compressors and Types of Systems
Conditioning Exam
Complete Practice Exam (100+ Questions)
Which of the following best describes "sensible heat" in an air conditioning context?
A) The heat required to change water to vapor
B) The heat associated with a change in temperature of a substance without a phase change
C) The heat associated with moisture in the air
D) The heat required to cool the refrigerant below saturation temperature
Correct Answer: B
Explanation: Sensible heat changes the temperature of a substance. Latent heat changes the
state (phase).
2. In the context of air conditioning, "latent heat" refers to:
A) Heat that directly raises the temperature of a substance
B) Heat required to induce a phase change without a temperature change
C) Additional heat from solar radiation
D) Heat lost through uninsulated ducts
Correct Answer: B
Explanation: Latent heat is the energy absorbed or released during a phase change (e.g., liquid to vapor)
at a constant temperature.
3. According to basic thermodynamic principles, heat naturally flows:
A) From cold objects to warmer objects
B) From warm objects to colder objects
C) Randomly in all directions
D) Only if driven by a compressor
Correct Answer: B
Explanation: The second law of thermodynamics states that heat flows from a region of higher
temperature to a region of lower temperature.
,4. The term "BTU" stands for:
A) British Thermal Unit
B) Boiler Temperature Unit
C) Basic Temperature Utility
D) Burn Time Unit
Correct Answer: A
Explanation: One BTU is the amount of heat needed to raise the temperature of one pound of water by
1°F.
5. In HVAC terminology, "ASHRAE" stands for:
A) American Society of Heating, Refrigerating and Air-Conditioning Engineers
B) Association of Systemic Heating and Refrigeration Engineers
C) American Service for Heat and Refrigeration Evaluation
D) Accredited Society of Home Air Regulation Experts
Correct Answer: A
Explanation: ASHRAE is the global standards-setting organization for HVAC/R.
6. The psychrometric chart is primarily used to analyze:
A) Electrical conductivity of refrigerants
B) Relationship between air temperature, moisture, and enthalpy
C) Efficiency of compressors in varying pressures
D) Fan performance curves
Correct Answer: B
Explanation: The psychrometric chart plots the properties of air, including dry-bulb temperature, wet-
bulb temperature, humidity, and enthalpy.
7. The primary goal of an air conditioning system is to:
A) Provide mechanical ventilation only
B) Control temperature, humidity, and indoor air quality
C) Refrigerate food products in large warehouses
D) Increase ambient noise for better acoustics
Correct Answer: B
, Explanation: Air conditioning is defined as the process of treating air to control its temperature,
humidity, cleanliness, and distribution.
8. Which of the following codes commonly governs HVAC installations in Louisiana?
A) International Mechanical Code (IMC)
B) Uniform Building Code (UBC)
C) National Electrical Code (NEC) – (While used, the question asks specifically for HVAC)
D) Federal Exhaust Standards (FES)
Correct Answer: A
Explanation: The International Mechanical Code (IMC) is widely adopted in Louisiana for HVAC
installations.
9. When referring to air conditioning loads, which of the following is considered an internal load?
A) Solar heat gain through windows
B) Heat gain from occupants and appliances
C) Heat loss through exterior walls
D) Infiltration from outside air
Correct Answer: B
Explanation: Internal loads are generated inside the conditioned space, such as people, lights, and
equipment.
10. In Louisiana, local amendments to the IMC may require additional considerations for:
A) Seismic anchoring
B) Flood protection and elevated equipment platforms
C) High-altitude condenser sizing
D) Sub-zero pipe insulation
Correct Answer: B
Explanation: Due to the high risk of flooding in New Orleans and Louisiana, mechanical equipment often
requires flood-proofing or elevation.
Section 2: Compressors and Types of Systems
