Mechanical Air Movement and Control Flashcards
How do we measure the volume of air passing through?
Cubic feet per minute (CFM)
What does SP stand for
Fan static pressure
K-Wheel blade
Blades cannot be adjusted.
A-Wheel blade
Blades can be adjusted when fan is not operating.
C-Wheel blade
Blades can be adjusted while fan is running
The three types of Axial Flow Fans are:
-Propeller fans
-Tubeaxial fans.
-Vaneaxial fans.
Which fan is the most used, can be found in industrial, commercia, institutional and residential applications and is often used indoors as an exhaust fan for general ventilation. (Axial Flow Fans)
Propeller Fan
Which type of fan can handle large volume of air at a low static pressure, usually have little to no ductwork, and are mounted directly onto the wall? (Axial Flow Fans)
Propeller fans
Which type of fans can be considered heavy duty propeller fans and are generally arranged for direct duct connection. (Axial Flow Fans)
Tubeaxial fans.
All axial fans discharge air in a spiral motion, which produces high duct system losses due to excessive turbulence. (T/F) (Axial Flow Fans)
True
Which type of fans is the most efficient and should be used whenever possible. (Axial Flow Fans)
Vaneaxial fans.
Whats the main difference between the tubeaxial and vaneaxial fan. (Axial Flow Fans)
The Vaneaxial fan has guide vanes behind the wheel to improve efficiency by straightening the airflow.
In centrifugal fans, the air leaves the impeller in a direction at right angles to the fan axis (T/F)
True
Centrifugal fans can be sub-grouped or classified by their fan (wheel) Blade types (T/F)
True
What are the 6 sub-group of centrifugal fans
- Centrifugal fans with airfoil blades.
- Centrifugal fans with Backward-Curved blades.
- Centrifugal fans with Backward-Inclined Blades.
- Centrifugal fans with Radial tip Blades.
- Centrifugal fans with Forward-curved blades.
- Centrifugal fans with Radial Blades.
What are the 4 types of blades configuration. (Centrifugal fans)
- Curved Blades.
- Inclined Blades.
- Airfoil Blades.
- Radial Blades.
What are centrifugal fans with forward curved blades best suited for ?
Application with higher airflow volumes volumes and pressures.
Airflow can be varied to match air distribution system requirements by making simple adjustments to the fan drive or control devices.
Forward curved fans are common in wheel diameters up to. (Centrifugal fans)
24â
Most up-flow residential heating equipment uses a centrifugal fan in what positional configuration.
CCWUBD
Counter-clockwise up blast discharge.
A 1000 cfm of air is to be moved through a duct system with a total pressure of 0.4âwc. Which type of fan is best suited.
Forward Curved Blade Centrifugal Fan
