Ohio HVAC Contractor Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. Which type of refrigerant has zero ozone depletion potential and is
commonly used in residential HVAC systems?
A. R-22
B. R-410A
C. R-134a
D. R-12
Rationale: R-410A is a hydrofluorocarbon (HFC) refrigerant with no
ozone depletion potential, replacing older R-22 systems.
2. What is the purpose of a heat exchanger in a furnace?
A. To filter the air
B. To compress refrigerant
C. To transfer heat from combustion gases to air
, D. To regulate airflow
Rationale: The heat exchanger transfers heat from combustion gases
to the air without mixing gases and air.
3. A typical split system air conditioner has how many main
components?
A. 1
B. 2
C. 4
D. 3
Rationale: A split system consists of the compressor, condenser,
expansion device, and evaporator.
4. What does SEER stand for in HVAC terminology?
A. Seasonal Energy Efficiency Ratio
B. Standard Energy Efficiency Rating
C. Seasonal Energy Efficiency Ratio
D. System Energy Efficiency Rate
Rationale: SEER measures the cooling efficiency of an air conditioner
over an entire cooling season.
5. Which type of thermostat allows for programming daily temperature
settings?
A. Mechanical thermostat
B. Digital programmable thermostat
C. Mercury switch thermostat
, D. Non-programmable thermostat
Rationale: Digital programmable thermostats allow setting different
temperatures for specific times of the day, improving energy
efficiency.
6. What is the primary purpose of a condensate drain in an air
conditioning system?
A. To remove refrigerant
B. To prevent ice formation
C. To remove moisture collected from the evaporator coil
D. To cool the compressor
Rationale: The condensate drain removes water formed from
condensation on the evaporator coil.
7. Which type of duct system is more energy-efficient for a residential
HVAC system?
A. Flexible duct
B. Sheet metal duct
C. Fabric duct
D. Open ceiling system
Rationale: Sheet metal ducts have less leakage and maintain airflow
more efficiently than flexible ducts.
8. A furnace that uses a blower to distribute heat is known as:
A. Radiant furnace
B. Steam furnace
, C. Forced-air furnace
D. Gravity furnace
Rationale: Forced-air furnaces use a blower to move heated air
through ducts.
9. What safety device prevents overheating in a gas furnace?
A. Pressure relief valve
B. Limit switch
C. Thermocouple
D. Expansion valve
Rationale: The limit switch shuts off the furnace if the temperature
exceeds safe levels.
10. When installing HVAC equipment in a crawl space, what is a
common requirement?
A. Use of flexible gas piping only
B. Adequate ventilation and moisture control
C. No insulation needed
D. Use of electric heat only
Rationale: Crawl spaces must be ventilated and moisture controlled
to prevent corrosion, mold, and equipment failure.
11. The primary purpose of refrigerant in an AC system is to:
A. Lubricate the compressor
B. Heat the air
C. Absorb and release heat during the refrigeration cycle
Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. Which type of refrigerant has zero ozone depletion potential and is
commonly used in residential HVAC systems?
A. R-22
B. R-410A
C. R-134a
D. R-12
Rationale: R-410A is a hydrofluorocarbon (HFC) refrigerant with no
ozone depletion potential, replacing older R-22 systems.
2. What is the purpose of a heat exchanger in a furnace?
A. To filter the air
B. To compress refrigerant
C. To transfer heat from combustion gases to air
, D. To regulate airflow
Rationale: The heat exchanger transfers heat from combustion gases
to the air without mixing gases and air.
3. A typical split system air conditioner has how many main
components?
A. 1
B. 2
C. 4
D. 3
Rationale: A split system consists of the compressor, condenser,
expansion device, and evaporator.
4. What does SEER stand for in HVAC terminology?
A. Seasonal Energy Efficiency Ratio
B. Standard Energy Efficiency Rating
C. Seasonal Energy Efficiency Ratio
D. System Energy Efficiency Rate
Rationale: SEER measures the cooling efficiency of an air conditioner
over an entire cooling season.
5. Which type of thermostat allows for programming daily temperature
settings?
A. Mechanical thermostat
B. Digital programmable thermostat
C. Mercury switch thermostat
, D. Non-programmable thermostat
Rationale: Digital programmable thermostats allow setting different
temperatures for specific times of the day, improving energy
efficiency.
6. What is the primary purpose of a condensate drain in an air
conditioning system?
A. To remove refrigerant
B. To prevent ice formation
C. To remove moisture collected from the evaporator coil
D. To cool the compressor
Rationale: The condensate drain removes water formed from
condensation on the evaporator coil.
7. Which type of duct system is more energy-efficient for a residential
HVAC system?
A. Flexible duct
B. Sheet metal duct
C. Fabric duct
D. Open ceiling system
Rationale: Sheet metal ducts have less leakage and maintain airflow
more efficiently than flexible ducts.
8. A furnace that uses a blower to distribute heat is known as:
A. Radiant furnace
B. Steam furnace
, C. Forced-air furnace
D. Gravity furnace
Rationale: Forced-air furnaces use a blower to move heated air
through ducts.
9. What safety device prevents overheating in a gas furnace?
A. Pressure relief valve
B. Limit switch
C. Thermocouple
D. Expansion valve
Rationale: The limit switch shuts off the furnace if the temperature
exceeds safe levels.
10. When installing HVAC equipment in a crawl space, what is a
common requirement?
A. Use of flexible gas piping only
B. Adequate ventilation and moisture control
C. No insulation needed
D. Use of electric heat only
Rationale: Crawl spaces must be ventilated and moisture controlled
to prevent corrosion, mold, and equipment failure.
11. The primary purpose of refrigerant in an AC system is to:
A. Lubricate the compressor
B. Heat the air
C. Absorb and release heat during the refrigeration cycle
