California HVAC Contractor Exam Questions
And Correct Answers (Verified Answers) Plus
Rationales 2025/2026 Q&A | Instant
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1. What is the primary function of a TXV (Thermostatic Expansion Valve) in an
HVAC system?
A. Increase airflow
B. Control humidity
C. Regulate refrigerant flow into the evaporator
D. Boost compressor pressure
The TXV regulates the amount of refrigerant entering the evaporator based on
temperature and load to ensure efficient heat absorption.
2. In a refrigeration cycle, where does the refrigerant absorb heat?
A. Compressor
B. Evaporator
C. Condenser
D. Expansion valve
The evaporator coil is where the refrigerant absorbs heat from the surrounding air
or medium.
,3. What must an HVAC contractor do before recovering refrigerant from a
system?
A. Install a new compressor
B. Verify refrigerant type and use EPA-approved recovery equipment
C. Bypass the filter drier
D. Open all service valves
Federal law requires identifying refrigerant and using proper recovery equipment
to prevent venting.
4. The airflow in a residential duct system is typically measured in what unit?
A. PSI
B. BTU/hr
C. CFM
D. Amperes
Cubic feet per minute (CFM) measures the volume of air moving through ducts.
5. What is the minimum SEER rating for a new central air conditioning unit
installed in California as of 2023?
A. 10
B. 12
C. 15
D. 18
,The minimum SEER (Seasonal Energy Efficiency Ratio) standard was raised to 15 in
California for improved energy efficiency.
6. What safety component is installed in gas furnaces to detect a flame?
A. Pilot switch
B. Fan relay
C. Flame sensor
D. Gas regulator
The flame sensor detects whether a flame is present to prevent unburned gas from
accumulating.
7. How far must a condensing unit be installed from a property line per
California Mechanical Code?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
A minimum clearance of 18 inches is required for access and airflow according to
code.
8. What does Manual J calculate?
A. Air duct sizing
B. Heating and cooling load
C. Ventilation rate
, D. Electrical load
Manual J determines the heating and cooling requirements for a building based on
climate, insulation, and square footage.
9. What gas is most commonly used in modern residential HVAC systems?
A. R-22
B. R-410A
C. Ammonia
D. R-12
R-410A replaced R-22 in residential systems due to environmental regulations.
10. A high head pressure in an air conditioning system usually indicates:
A. A dirty evaporator
B. A dirty condenser or overcharge
C. A leaking metering device
D. Low ambient temperature
Restricted airflow or overcharging the system causes high head pressure,
especially at the condenser.
11. What type of test checks for leaks in a newly installed refrigerant line set?
A. Voltage test
B. Nitrogen pressure test
C. Vacuum hold test
D. Continuity test
And Correct Answers (Verified Answers) Plus
Rationales 2025/2026 Q&A | Instant
Download Pdf
1. What is the primary function of a TXV (Thermostatic Expansion Valve) in an
HVAC system?
A. Increase airflow
B. Control humidity
C. Regulate refrigerant flow into the evaporator
D. Boost compressor pressure
The TXV regulates the amount of refrigerant entering the evaporator based on
temperature and load to ensure efficient heat absorption.
2. In a refrigeration cycle, where does the refrigerant absorb heat?
A. Compressor
B. Evaporator
C. Condenser
D. Expansion valve
The evaporator coil is where the refrigerant absorbs heat from the surrounding air
or medium.
,3. What must an HVAC contractor do before recovering refrigerant from a
system?
A. Install a new compressor
B. Verify refrigerant type and use EPA-approved recovery equipment
C. Bypass the filter drier
D. Open all service valves
Federal law requires identifying refrigerant and using proper recovery equipment
to prevent venting.
4. The airflow in a residential duct system is typically measured in what unit?
A. PSI
B. BTU/hr
C. CFM
D. Amperes
Cubic feet per minute (CFM) measures the volume of air moving through ducts.
5. What is the minimum SEER rating for a new central air conditioning unit
installed in California as of 2023?
A. 10
B. 12
C. 15
D. 18
,The minimum SEER (Seasonal Energy Efficiency Ratio) standard was raised to 15 in
California for improved energy efficiency.
6. What safety component is installed in gas furnaces to detect a flame?
A. Pilot switch
B. Fan relay
C. Flame sensor
D. Gas regulator
The flame sensor detects whether a flame is present to prevent unburned gas from
accumulating.
7. How far must a condensing unit be installed from a property line per
California Mechanical Code?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
A minimum clearance of 18 inches is required for access and airflow according to
code.
8. What does Manual J calculate?
A. Air duct sizing
B. Heating and cooling load
C. Ventilation rate
, D. Electrical load
Manual J determines the heating and cooling requirements for a building based on
climate, insulation, and square footage.
9. What gas is most commonly used in modern residential HVAC systems?
A. R-22
B. R-410A
C. Ammonia
D. R-12
R-410A replaced R-22 in residential systems due to environmental regulations.
10. A high head pressure in an air conditioning system usually indicates:
A. A dirty evaporator
B. A dirty condenser or overcharge
C. A leaking metering device
D. Low ambient temperature
Restricted airflow or overcharging the system causes high head pressure,
especially at the condenser.
11. What type of test checks for leaks in a newly installed refrigerant line set?
A. Voltage test
B. Nitrogen pressure test
C. Vacuum hold test
D. Continuity test
