CO HVAC Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A| Instant Download Pdf
1. What is the primary purpose of an HVAC system?
A. To generate electricity
B. To provide heating, ventilation, and air conditioning
C. To filter water
D. To reduce noise pollution
B. To provide heating, ventilation, and air conditioning
Rationale: The primary purpose of HVAC systems is to maintain
indoor air quality and comfort through heating, cooling, and
ventilation.
2. Which refrigerant has been commonly used in older residential air
conditioning systems?
A. R-134a
B. R-410A
C. R-22
D. R-32
C. R-22
Rationale: R-22 (Freon) was widely used but is being phased out due
to ozone depletion concerns.
3. What is the standard air conditioning temperature range for comfort in
residential buildings?
A. 50–60°F
B. 68–78°F
C. 80–90°F
D. 60–65°F
B. 68–78°F
, Rationale: This range provides thermal comfort for most people
indoors.
4. What is the function of a condenser in an HVAC system?
A. To absorb heat from the indoor air
B. To compress refrigerant
C. To release heat from refrigerant to the outside
D. To circulate water in heating systems
C. To release heat from refrigerant to the outside
Rationale: The condenser allows the refrigerant to release heat
absorbed from indoor spaces.
5. Which device regulates the flow of refrigerant into the evaporator coil?
A. Expansion valve
B. Compressor
C. Condenser fan
D. Thermostat
A. Expansion valve
Rationale: The expansion valve controls refrigerant flow,
maintaining optimal cooling efficiency.
6. What is the main purpose of a thermostat in HVAC systems?
A. To filter air
B. To measure humidity
C. To regulate temperature automatically
D. To compress refrigerant
C. To regulate temperature automatically
Rationale: Thermostats sense temperature and control HVAC
operation to maintain desired comfort levels.
7. Which type of HVAC system uses ductless air handlers for heating and
cooling individual rooms?
A. Split system
B. Packaged system
C. Ductless mini-split system
D. Chiller system
C. Ductless mini-split system
Rationale: Mini-split systems provide independent room temperature
control without ductwork.
8. What is the function of the evaporator coil in an air conditioning
system?
, A. To release heat to the outdoors
B. To absorb heat from indoor air
C. To circulate refrigerant through the compressor
D. To measure air pressure
B. To absorb heat from indoor air
Rationale: The evaporator coil absorbs heat from the indoor air,
cooling the space.
9. What type of maintenance should be performed regularly to ensure
HVAC efficiency?
A. Replace circuit breakers
B. Clean or replace air filters
C. Paint exterior unit
D. Replace refrigerant daily
B. Clean or replace air filters
Rationale: Dirty filters reduce airflow and efficiency, leading to
higher energy consumption and wear on equipment.
10. What does SEER stand for in HVAC systems?
A. Seasonal Energy Efficiency Ratio
B. Standard Electrical Energy Rating
C. Seasonal Environmental Efficiency Ratio
D. System Energy Electrical Ratio
A. Seasonal Energy Efficiency Ratio
Rationale: SEER measures the cooling efficiency of air conditioners
over a typical cooling season.
11. Which gas is used in modern high-efficiency residential air
conditioners?
A. R-22
B. R-134a
C. R-410A
D. R-12
C. R-410A
Rationale: R-410A is widely used due to its ozone-safe properties and
efficiency.
12. What is the primary function of a blower in an HVAC system?
A. To heat water
B. To move air through ducts and vents
C. To compress refrigerant
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A| Instant Download Pdf
1. What is the primary purpose of an HVAC system?
A. To generate electricity
B. To provide heating, ventilation, and air conditioning
C. To filter water
D. To reduce noise pollution
B. To provide heating, ventilation, and air conditioning
Rationale: The primary purpose of HVAC systems is to maintain
indoor air quality and comfort through heating, cooling, and
ventilation.
2. Which refrigerant has been commonly used in older residential air
conditioning systems?
A. R-134a
B. R-410A
C. R-22
D. R-32
C. R-22
Rationale: R-22 (Freon) was widely used but is being phased out due
to ozone depletion concerns.
3. What is the standard air conditioning temperature range for comfort in
residential buildings?
A. 50–60°F
B. 68–78°F
C. 80–90°F
D. 60–65°F
B. 68–78°F
, Rationale: This range provides thermal comfort for most people
indoors.
4. What is the function of a condenser in an HVAC system?
A. To absorb heat from the indoor air
B. To compress refrigerant
C. To release heat from refrigerant to the outside
D. To circulate water in heating systems
C. To release heat from refrigerant to the outside
Rationale: The condenser allows the refrigerant to release heat
absorbed from indoor spaces.
5. Which device regulates the flow of refrigerant into the evaporator coil?
A. Expansion valve
B. Compressor
C. Condenser fan
D. Thermostat
A. Expansion valve
Rationale: The expansion valve controls refrigerant flow,
maintaining optimal cooling efficiency.
6. What is the main purpose of a thermostat in HVAC systems?
A. To filter air
B. To measure humidity
C. To regulate temperature automatically
D. To compress refrigerant
C. To regulate temperature automatically
Rationale: Thermostats sense temperature and control HVAC
operation to maintain desired comfort levels.
7. Which type of HVAC system uses ductless air handlers for heating and
cooling individual rooms?
A. Split system
B. Packaged system
C. Ductless mini-split system
D. Chiller system
C. Ductless mini-split system
Rationale: Mini-split systems provide independent room temperature
control without ductwork.
8. What is the function of the evaporator coil in an air conditioning
system?
, A. To release heat to the outdoors
B. To absorb heat from indoor air
C. To circulate refrigerant through the compressor
D. To measure air pressure
B. To absorb heat from indoor air
Rationale: The evaporator coil absorbs heat from the indoor air,
cooling the space.
9. What type of maintenance should be performed regularly to ensure
HVAC efficiency?
A. Replace circuit breakers
B. Clean or replace air filters
C. Paint exterior unit
D. Replace refrigerant daily
B. Clean or replace air filters
Rationale: Dirty filters reduce airflow and efficiency, leading to
higher energy consumption and wear on equipment.
10. What does SEER stand for in HVAC systems?
A. Seasonal Energy Efficiency Ratio
B. Standard Electrical Energy Rating
C. Seasonal Environmental Efficiency Ratio
D. System Energy Electrical Ratio
A. Seasonal Energy Efficiency Ratio
Rationale: SEER measures the cooling efficiency of air conditioners
over a typical cooling season.
11. Which gas is used in modern high-efficiency residential air
conditioners?
A. R-22
B. R-134a
C. R-410A
D. R-12
C. R-410A
Rationale: R-410A is widely used due to its ozone-safe properties and
efficiency.
12. What is the primary function of a blower in an HVAC system?
A. To heat water
B. To move air through ducts and vents
C. To compress refrigerant
