CA D-62 Air & Water Balancing Contractor
Exam Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary scope of a California D-62 Air and Water
Balancing Contractor?
A. Installing residential plumbing fixtures
B. Installing electrical distribution systems
C. Providing specified airflow in existing heating and cooling systems
and/or specified water flow in water piping systems
D. Installing structural steel systems
Answer: C. Providing specified airflow in existing heating and cooling
systems and/or specified water flow in water piping systems
Rationale: The D-62 classification covers work and devices associated
with achieving specified airflows in existing heating and cooling systems
and specified water flows in water piping systems. This makes
,measurement, adjustment, and verification of system performance
central to the classification.
2. Which measurement is most directly associated with determining
airflow through a duct?
A. Voltage
B. Cubic feet per minute
C. Ohms
D. Gallons per minute
Answer: B. Cubic feet per minute
Rationale: Cubic feet per minute (CFM) is the standard volumetric
airflow unit commonly used when balancing HVAC air systems. Voltage
and ohms relate to electrical measurements, while gallons per minute is
used for liquid flow.
3. Which instrument is commonly used to measure air velocity at a
grille or diffuser?
A. Anemometer
B. Megohmmeter
C. Clamp meter
D. Hydrometer
Answer: A. Anemometer
,Rationale: An anemometer measures air velocity. When used
appropriately at a diffuser, grille, or duct opening, velocity readings can
be used with area measurements to estimate airflow.
4. A pitot-tube traverse is primarily used to determine what?
A. Electrical resistance
B. Duct airflow
C. Pipe-wall thickness
D. Water temperature
Answer: B. Duct airflow
Rationale: A pitot-tube traverse measures velocity pressure at multiple
points across a duct. The resulting velocity-pressure data can be used to
calculate average velocity and airflow.
5. What is the basic relationship between airflow, velocity, and duct
area?
A. CFM = velocity × area
B. CFM = velocity ÷ area
C. CFM = area ÷ velocity
D. CFM = velocity + area
Answer: A. CFM = velocity × area
, Rationale: Volumetric airflow is calculated by multiplying average air
velocity by the cross-sectional area through which the air moves.
Consistent units must be used for the calculation.
6. What is the primary purpose of balancing an air distribution
system?
A. To increase electrical voltage
B. To distribute airflow according to design requirements
C. To eliminate all duct fittings
D. To replace the HVAC control system
Answer: B. To distribute airflow according to design requirements
Rationale: Air balancing adjusts the system so that rooms, zones,
terminals, and branches receive airflow consistent with the intended
design or approved balancing requirements. Proper distribution
supports comfort, ventilation, and system performance.
7. Which device is commonly adjusted to regulate airflow in a duct
branch?
A. Circuit breaker
B. Balancing damper
C. Water heater thermostat
D. Electrical transformer
Exam Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary scope of a California D-62 Air and Water
Balancing Contractor?
A. Installing residential plumbing fixtures
B. Installing electrical distribution systems
C. Providing specified airflow in existing heating and cooling systems
and/or specified water flow in water piping systems
D. Installing structural steel systems
Answer: C. Providing specified airflow in existing heating and cooling
systems and/or specified water flow in water piping systems
Rationale: The D-62 classification covers work and devices associated
with achieving specified airflows in existing heating and cooling systems
and specified water flows in water piping systems. This makes
,measurement, adjustment, and verification of system performance
central to the classification.
2. Which measurement is most directly associated with determining
airflow through a duct?
A. Voltage
B. Cubic feet per minute
C. Ohms
D. Gallons per minute
Answer: B. Cubic feet per minute
Rationale: Cubic feet per minute (CFM) is the standard volumetric
airflow unit commonly used when balancing HVAC air systems. Voltage
and ohms relate to electrical measurements, while gallons per minute is
used for liquid flow.
3. Which instrument is commonly used to measure air velocity at a
grille or diffuser?
A. Anemometer
B. Megohmmeter
C. Clamp meter
D. Hydrometer
Answer: A. Anemometer
,Rationale: An anemometer measures air velocity. When used
appropriately at a diffuser, grille, or duct opening, velocity readings can
be used with area measurements to estimate airflow.
4. A pitot-tube traverse is primarily used to determine what?
A. Electrical resistance
B. Duct airflow
C. Pipe-wall thickness
D. Water temperature
Answer: B. Duct airflow
Rationale: A pitot-tube traverse measures velocity pressure at multiple
points across a duct. The resulting velocity-pressure data can be used to
calculate average velocity and airflow.
5. What is the basic relationship between airflow, velocity, and duct
area?
A. CFM = velocity × area
B. CFM = velocity ÷ area
C. CFM = area ÷ velocity
D. CFM = velocity + area
Answer: A. CFM = velocity × area
, Rationale: Volumetric airflow is calculated by multiplying average air
velocity by the cross-sectional area through which the air moves.
Consistent units must be used for the calculation.
6. What is the primary purpose of balancing an air distribution
system?
A. To increase electrical voltage
B. To distribute airflow according to design requirements
C. To eliminate all duct fittings
D. To replace the HVAC control system
Answer: B. To distribute airflow according to design requirements
Rationale: Air balancing adjusts the system so that rooms, zones,
terminals, and branches receive airflow consistent with the intended
design or approved balancing requirements. Proper distribution
supports comfort, ventilation, and system performance.
7. Which device is commonly adjusted to regulate airflow in a duct
branch?
A. Circuit breaker
B. Balancing damper
C. Water heater thermostat
D. Electrical transformer
