CDC 3E151 - HVAC/R JOURNEYMAN VOLUME 2 EXAM QUESTIONS
AND ANSWERS WITH COMPLETE 100% VERIFIED SOLUTIONS
(201) What affect will dust on fan blades have on heat transfer?
It will reduce heat transfer
(201) Where do you view the rotation and discharge of a centrifugal fan?
On the drive side
(201) Why are vanes used in the vane axial fan?
To straighten out the spiraling motion of the air
(201) What will allow a sheave to be used on different diameter shafts?
Bushings
(201) Where will the classic V-belts ( A through E ) be used?
Medium horsepower applications
(201) If you have four belts and one is bad, how many should you replace?
4
(202) In a single-duct unit, why is the manual damper left in its initial position?
To maintain a constant airflow through the box
(202) Which design(s) do multiple-path systems use?
Separate cold- and warm-air duct distribution systems or separate supply duct to each
zone
(202) Why are multi-path, multi-zone systems limited to smaller areas?
Because of the multiple runs of single-zone ducts
, (202) If a cooling demand is reduced in a building, what will the supply dampers
do?
Begin to close
(202) What is one reason for the use of terminal reheat?
Allow zone or space control for areas of unequal loading
(202) What makes an independent variable air volume (VAV) system truly
independent?
They can control the maximum and minimum cfm that can be supplied from the box
(203) How do you prevent carryover into the ductwork while using atomizing
sprays?
Using an eliminator or filter
(203) When is the use of a return air system generally essential?
On larger systems
(203) What is the result of a dirty or clogged filter?
Resistance to flow and reduced efficiency
(203) What causes the adjacent blades on an opposed-blade damper to move in
opposite directions?
A linkage
(204) What does carbon monoxide combine with no interfere with the oxygen
supply?
Hemoglobin
(204) What will affect a person's sensitivity to an odor?
Temperature and humidity
AND ANSWERS WITH COMPLETE 100% VERIFIED SOLUTIONS
(201) What affect will dust on fan blades have on heat transfer?
It will reduce heat transfer
(201) Where do you view the rotation and discharge of a centrifugal fan?
On the drive side
(201) Why are vanes used in the vane axial fan?
To straighten out the spiraling motion of the air
(201) What will allow a sheave to be used on different diameter shafts?
Bushings
(201) Where will the classic V-belts ( A through E ) be used?
Medium horsepower applications
(201) If you have four belts and one is bad, how many should you replace?
4
(202) In a single-duct unit, why is the manual damper left in its initial position?
To maintain a constant airflow through the box
(202) Which design(s) do multiple-path systems use?
Separate cold- and warm-air duct distribution systems or separate supply duct to each
zone
(202) Why are multi-path, multi-zone systems limited to smaller areas?
Because of the multiple runs of single-zone ducts
, (202) If a cooling demand is reduced in a building, what will the supply dampers
do?
Begin to close
(202) What is one reason for the use of terminal reheat?
Allow zone or space control for areas of unequal loading
(202) What makes an independent variable air volume (VAV) system truly
independent?
They can control the maximum and minimum cfm that can be supplied from the box
(203) How do you prevent carryover into the ductwork while using atomizing
sprays?
Using an eliminator or filter
(203) When is the use of a return air system generally essential?
On larger systems
(203) What is the result of a dirty or clogged filter?
Resistance to flow and reduced efficiency
(203) What causes the adjacent blades on an opposed-blade damper to move in
opposite directions?
A linkage
(204) What does carbon monoxide combine with no interfere with the oxygen
supply?
Hemoglobin
(204) What will affect a person's sensitivity to an odor?
Temperature and humidity
