Tennessee HVAC Contractor Exam
(CMC-C) Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. A Tennessee HVAC contractor installing a commercial rooftop unit
must ensure compliance with which code primarily governing
mechanical systems installation?
A. National Electrical Code (NEC)
B. International Plumbing Code (IPC)
C. International Mechanical Code (IMC)
D. International Residential Code (IRC)
Answer: C
The International Mechanical Code (IMC) governs the installation,
maintenance, and inspection of HVAC systems in commercial
applications, making it the primary code for such installations.
,2. When calculating heating load using Manual J principles, which factor
has the greatest influence on heat loss?
A. Interior paint color
B. Insulation R-value
C. Flooring material
D. Ceiling fan speed
Answer: B
The insulation R-value significantly impacts heat loss by determining
how well a building resists heat flow, making it a primary factor in
load calculations.
3. What is the minimum required clearance for most gas-fired furnaces
from combustible materials unless otherwise specified?
A. 0 inches
B. 1 inch
C. 6 inches
D. 12 inches
Answer: C
Most gas furnaces require at least 6 inches of clearance from
combustibles to prevent fire hazards, though manufacturer
instructions may vary.
4. Which device is used to measure refrigerant pressure in an HVAC
system?
A. Hygrometer
B. Manometer
C. Thermocouple
D. Psychrometer
Answer: B
A manometer measures pressure in a system, including refrigerant
pressures, making it essential for HVAC diagnostics.
5. In a vapor-compression refrigeration cycle, what component increases
the pressure of refrigerant vapor?
A. Evaporator
B. Condenser
C. Compressor
D. Expansion valve
, Answer: C
The compressor raises the pressure and temperature of refrigerant
vapor, enabling heat rejection in the condenser.
6. Which refrigerant has been phased out due to ozone depletion
potential?
A. R-410A
B. R-134a
C. R-22
D. R-32
Answer: C
R-22 has been phased out because it contributes to ozone depletion,
in accordance with environmental regulations.
7. What is the primary purpose of a condenser in an HVAC system?
A. Absorb heat from indoor air
B. Reject heat to the outdoors
C. Increase refrigerant velocity
D. Reduce airflow resistance
Answer: B
The condenser releases absorbed heat from the refrigerant to the
outdoor environment, completing the heat transfer cycle.
8. Which law explains the relationship between pressure, volume, and
temperature of a gas?
A. Ohm’s Law
B. Boyle’s Law
C. Charles’s Law
D. Combined Gas Law
Answer: D
The Combined Gas Law incorporates pressure, volume, and
temperature relationships, making it fundamental in HVAC
thermodynamics.
9. What type of duct system is most efficient in minimizing air leakage?
A. Flexible duct
B. Fiberboard duct
C. Sheet metal duct
D. Open return plenum
(CMC-C) Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A Tennessee HVAC contractor installing a commercial rooftop unit
must ensure compliance with which code primarily governing
mechanical systems installation?
A. National Electrical Code (NEC)
B. International Plumbing Code (IPC)
C. International Mechanical Code (IMC)
D. International Residential Code (IRC)
Answer: C
The International Mechanical Code (IMC) governs the installation,
maintenance, and inspection of HVAC systems in commercial
applications, making it the primary code for such installations.
,2. When calculating heating load using Manual J principles, which factor
has the greatest influence on heat loss?
A. Interior paint color
B. Insulation R-value
C. Flooring material
D. Ceiling fan speed
Answer: B
The insulation R-value significantly impacts heat loss by determining
how well a building resists heat flow, making it a primary factor in
load calculations.
3. What is the minimum required clearance for most gas-fired furnaces
from combustible materials unless otherwise specified?
A. 0 inches
B. 1 inch
C. 6 inches
D. 12 inches
Answer: C
Most gas furnaces require at least 6 inches of clearance from
combustibles to prevent fire hazards, though manufacturer
instructions may vary.
4. Which device is used to measure refrigerant pressure in an HVAC
system?
A. Hygrometer
B. Manometer
C. Thermocouple
D. Psychrometer
Answer: B
A manometer measures pressure in a system, including refrigerant
pressures, making it essential for HVAC diagnostics.
5. In a vapor-compression refrigeration cycle, what component increases
the pressure of refrigerant vapor?
A. Evaporator
B. Condenser
C. Compressor
D. Expansion valve
, Answer: C
The compressor raises the pressure and temperature of refrigerant
vapor, enabling heat rejection in the condenser.
6. Which refrigerant has been phased out due to ozone depletion
potential?
A. R-410A
B. R-134a
C. R-22
D. R-32
Answer: C
R-22 has been phased out because it contributes to ozone depletion,
in accordance with environmental regulations.
7. What is the primary purpose of a condenser in an HVAC system?
A. Absorb heat from indoor air
B. Reject heat to the outdoors
C. Increase refrigerant velocity
D. Reduce airflow resistance
Answer: B
The condenser releases absorbed heat from the refrigerant to the
outdoor environment, completing the heat transfer cycle.
8. Which law explains the relationship between pressure, volume, and
temperature of a gas?
A. Ohm’s Law
B. Boyle’s Law
C. Charles’s Law
D. Combined Gas Law
Answer: D
The Combined Gas Law incorporates pressure, volume, and
temperature relationships, making it fundamental in HVAC
thermodynamics.
9. What type of duct system is most efficient in minimizing air leakage?
A. Flexible duct
B. Fiberboard duct
C. Sheet metal duct
D. Open return plenum
