NATE AIR DISTRIBUTION INDUSTRY COMPETENCY
EXAM
Cross breaking sheet metal duct will:
a. Weaken the duct and prevent contamination.
b. Stiffen the duct and reduce noise.
c. Increase the cost of the duct and prevent joint splitting.
d. Improve the appearance of the duct and prevent zinc cracking. - Answers- B
Which of the following is one of the most common disadvantages of using flex duct in
comparison to sheet metal duct?
a. Less pressure drop.
b. More fittings required.
c. More pressure drop.
d. Increased installation time. - Answers- C
Which instrument is used to check the velocity of air through a coil or of air coming out
of a duct outlet?
a. Pyrometer.
b. Velometer.
c. Hygrometer.
d. Refractometer. - Answers- B
In a 12"x12" ID duct the air velocity is measured at 800fpm, what is the airflow?
a. 144 CFM.
b. 400 CFM.
c. 800 CFM.
d. 1600 CFM. - Answers- C
A correct statement about balancing the air distribution in a forced air heating system is
that this procedure:
a. Is best accomplished with room registers.
b. Would not involve adjustment of the fan speed.
c. Cannot be accomplished by proper duct design.
d. Maintains the same temperature in every room in the home. - Answers- D
To accurately measure velocity pressure with a pitot tube, the point of the pitot tube
should point:
, a. Into the air stream.
b. Downstream.
c. At a 45-degree angle to the air stream.
d. At a 90-degree angle to the air stream. - Answers- A
A supply duct in an unconditioned space has a significant leak, but the return duct is
properly sealed. this leak will cause:
a. Negative pressure in the unconditioned space.
b. No pressure change in the conditioned space.
c. Negative pressure in the conditioned space.
d. Positive pressure in the conditioned space. - Answers- C
Which instrument can be used to check the velocity of air through a register?
a. Pyrometer.
b. Anemometer.
c. Hygrometer.
d. Tachometer. - Answers- B
Velocity pressure is computed by subtracting the static pressure from the:
a. Absolute pressure.
b. Gauge pressure.
c. Total pressure.
d. Differential pressure. - Answers- C
The tool most commonly used to cut circles in sheet metal is the:
a. Notcher.
b. Aviation snip.
c. Bulldog snip.
d. Crimper. - Answers- B
The purpose of using a flexible duct connector between the air handler and the sheet
metal duct is to:
a. Simplify the installation of a central air handler and ductwork system.
b. Eliminate the transmission of vibrations from the air handler to ductwork.
c. Provide a convenient site for obtaining temperature and static pressure readings.
d. Provide a leak proof connection. - Answers- B
What instrument is used to measure static pressure drop across a cooling coil?
a. Inclined manometer.
EXAM
Cross breaking sheet metal duct will:
a. Weaken the duct and prevent contamination.
b. Stiffen the duct and reduce noise.
c. Increase the cost of the duct and prevent joint splitting.
d. Improve the appearance of the duct and prevent zinc cracking. - Answers- B
Which of the following is one of the most common disadvantages of using flex duct in
comparison to sheet metal duct?
a. Less pressure drop.
b. More fittings required.
c. More pressure drop.
d. Increased installation time. - Answers- C
Which instrument is used to check the velocity of air through a coil or of air coming out
of a duct outlet?
a. Pyrometer.
b. Velometer.
c. Hygrometer.
d. Refractometer. - Answers- B
In a 12"x12" ID duct the air velocity is measured at 800fpm, what is the airflow?
a. 144 CFM.
b. 400 CFM.
c. 800 CFM.
d. 1600 CFM. - Answers- C
A correct statement about balancing the air distribution in a forced air heating system is
that this procedure:
a. Is best accomplished with room registers.
b. Would not involve adjustment of the fan speed.
c. Cannot be accomplished by proper duct design.
d. Maintains the same temperature in every room in the home. - Answers- D
To accurately measure velocity pressure with a pitot tube, the point of the pitot tube
should point:
, a. Into the air stream.
b. Downstream.
c. At a 45-degree angle to the air stream.
d. At a 90-degree angle to the air stream. - Answers- A
A supply duct in an unconditioned space has a significant leak, but the return duct is
properly sealed. this leak will cause:
a. Negative pressure in the unconditioned space.
b. No pressure change in the conditioned space.
c. Negative pressure in the conditioned space.
d. Positive pressure in the conditioned space. - Answers- C
Which instrument can be used to check the velocity of air through a register?
a. Pyrometer.
b. Anemometer.
c. Hygrometer.
d. Tachometer. - Answers- B
Velocity pressure is computed by subtracting the static pressure from the:
a. Absolute pressure.
b. Gauge pressure.
c. Total pressure.
d. Differential pressure. - Answers- C
The tool most commonly used to cut circles in sheet metal is the:
a. Notcher.
b. Aviation snip.
c. Bulldog snip.
d. Crimper. - Answers- B
The purpose of using a flexible duct connector between the air handler and the sheet
metal duct is to:
a. Simplify the installation of a central air handler and ductwork system.
b. Eliminate the transmission of vibrations from the air handler to ductwork.
c. Provide a convenient site for obtaining temperature and static pressure readings.
d. Provide a leak proof connection. - Answers- B
What instrument is used to measure static pressure drop across a cooling coil?
a. Inclined manometer.
