Centrifugal FanTypes
The major types of centrifugal fan are: radial, forward curved and backward curved .
Radial fans are industrial workhorses because of their high static pressures (up to 1400 mmWC ) and ability to handle
heavily contaminated air streams. Because of their simple design,radial fans are well suited for high temperatures and medium blade tip speeds.
Forward-curved fans are used in clean environments and operate at lower temperatures.They are well suited for low tip speed and high-airflow work - they are best suited for moving
large volumes of air against relatively low pressures.
Backward-inclined fans are more efficient than forward-curved fans. Backward-inclined fans reach their peak power consumption and then power demand drops off well within their useable airflow range. Backward-inclined fans are known as "non-overloading" because changes in static pressure do not overload the motor.
Axial Flow Fan Types
The major types of axial flow fans are: tube axial, vane axial and propeller
Tubeaxial fans have a wheel inside a cylindrical housing, with close clearance between blade and housing to improve airflow efficiency. The wheel turn faster than propeller fans,
enabling operation under high-pressures 250 – 400 mm WC. The efficiency is up to 65%.
Vaneaxial fans are similar to tubeaxials, but with addition of guide vanes that improve efficiency by directing and straightening the flow. As a result, they have a higher static pressure with less dependence on the duct static pressure. Such fans are used generally for pressures upto 500 mmWC. Vaneaxials are typically the most energy-efficient fans available and should beused whenever possible.
Propeller fans usually run at low speeds and moderate temperatures. They experience a large change in airflow with small changes in static pressure. They handle large volumes of air at low pressure or free delivery. Propeller fans are often used indoors as exhaust fans. Outdoor applications include air-cooled condensers and cooling towers. Efficiency is low – approximately
50% or less.
The major types of centrifugal fan are: radial, forward curved and backward curved .
Radial fans are industrial workhorses because of their high static pressures (up to 1400 mmWC ) and ability to handle
heavily contaminated air streams. Because of their simple design,radial fans are well suited for high temperatures and medium blade tip speeds.
Forward-curved fans are used in clean environments and operate at lower temperatures.They are well suited for low tip speed and high-airflow work - they are best suited for moving
large volumes of air against relatively low pressures.
Backward-inclined fans are more efficient than forward-curved fans. Backward-inclined fans reach their peak power consumption and then power demand drops off well within their useable airflow range. Backward-inclined fans are known as "non-overloading" because changes in static pressure do not overload the motor.
Axial Flow Fan Types
The major types of axial flow fans are: tube axial, vane axial and propeller
Tubeaxial fans have a wheel inside a cylindrical housing, with close clearance between blade and housing to improve airflow efficiency. The wheel turn faster than propeller fans,
enabling operation under high-pressures 250 – 400 mm WC. The efficiency is up to 65%.
Vaneaxial fans are similar to tubeaxials, but with addition of guide vanes that improve efficiency by directing and straightening the flow. As a result, they have a higher static pressure with less dependence on the duct static pressure. Such fans are used generally for pressures upto 500 mmWC. Vaneaxials are typically the most energy-efficient fans available and should beused whenever possible.
Propeller fans usually run at low speeds and moderate temperatures. They experience a large change in airflow with small changes in static pressure. They handle large volumes of air at low pressure or free delivery. Propeller fans are often used indoors as exhaust fans. Outdoor applications include air-cooled condensers and cooling towers. Efficiency is low – approximately
50% or less.
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