Bathroom Exhaust fans Did you know that electric fans can do more than just cool? Fans circulate the air and keep it in motion, maintaining a fresh breeze that cools as well as keeping humidity levels in check. Fans also add ventilation and prevent the inhalation of dangerous gases and fumes. Choosing the Right Type of Fan The only tricky thing about purchasing a fan is finding which style you need.
A diagram of a centrifugal fan, with top view to show airflow.
Often called a "squirrel cage" because of its general similarity in appearance to exercise wheels for pet rodents or "scroll fan", the centrifugal fan has a moving component called an Types of fans that consists of a central shaft about which a set of blades form a spiralor ribs, are positioned.
Centrifugal fans blow air at right angles to the intake of the fan, and spin the air outwards to the outlet by deflection and centrifugal force. The impeller rotates, causing air to enter the fan near the shaft and move perpendicularly from the shaft to the opening in the scroll-shaped fan casing.
A centrifugal fan produces more pressure for a given air volume, and is used where this is desirable such as in leaf blowersblowdryersair mattress inflators, inflatable structuresclimate controland various industrial purposes.
They are typically quieter than comparable axial fans.
Cross-flow fan[ edit ] Cross-section of cross-flow fan, from the patent. The rotation is clock-wise. The stream guide F is usually not present in modern implementations. Cross-flow fan The cross-flow or tangential fan, sometimes known as a tubular fan, was patented in by Paul Mortier,  and is used extensively in the HVAC industry.
The fan is usually long in relation to the diameter, so the flow approximately remains two-dimensional away from the ends. The CFF uses an impeller with forward curved blades, placed in a housing consisting of a rear wall and vortex wall.
Unlike radial machines, the main flow moves transversely across the impeller, passing the blading twice. The flow within a cross-flow fan may be broken up into three distinct regions: Both the vortex and paddling regions are dissipative, and as a result, only a portion of the impeller imparts usable work on the flow.
The cross-flow fan, or transverse fan, is thus a two-stage partial admission machine. The popularity of the crossflow fan in the HVAC industry comes from its compactness, shape, quiet operation, and ability to provide high pressure coefficient.
Effectively a rectangular fan in terms of inlet and outlet geometry, the diameter readily scales to fit the available space, and the length is adjustable to meet flow rate requirements for the particular application.
Common household tower fans are also cross-flow fans. Much of the early work focused on developing the cross-flow fan for both high and low-flow-rate conditions, and resulted in numerous patents.
One interesting phenomenon particular to the cross-flow fan is that, as the blades rotate, the local air incidence angle changes. The result is that in certain positions the blades act as compressors pressure increasewhile at other azimuthal locations the blades act as turbines pressure decrease. Since the flow both enters and exits the impeller radially, the crossflow fan is well suited for aircraft applications.
Due to the 2D nature of the flow, the fan readily integrates into a wing for use in both thrust production and boundary-layer control.
A configuration that utilizes a crossflow fan is located at the wing leading edge is the fanwing. This design creates lift by deflecting the wake downward due to the rotational direction of the fan, causing large Magnus force, similar to a spinning leading-edge cylinder.
Another configuration utilizing a crossflow fan for thrust and flow control is the propulsive wing. In this design, the crossflow fan is placed near the trailing edge of a thick wing, and draws the air off the wing's suction top surface.
By doing this, the propulsive wing is nearly stall-free, even at extremely high angles of attack, producing very high lift.
The external links section provides links to these concepts. A cross flow fan, is a centrifugal fan in which the air flows through the fan, rather than through an inlet.
The rotor of a cross flow fan is covered to create a pressure differential. When used in household fans, cross flow fans have smaller opening on one side and a larger opening on the other. Cross flow fans have openings of different sizes on the front and rear sides.
The resultant pressure difference allows air to flow straight through the fan, even though the fan blades counter the flow of air on one side of the rotation. Cross flow fans give airflow along the entire width of the fan, however, they are noiser than ordinary centrifugal fans presumedly because the fan blades fight the flow of air on one side of the rotation unlike normal squirrel cage fans.
Cross flow fans are often used in air conditionersautomobile ventilation systems, and for cooling in medium-sized equipment such as photocopiers. The action of a fan or blower causes pressures slightly above atmospheric, which are called plenums.
Bladeless Indirect viscous-shear fan[ edit ] This section may be too technical for most readers to understand. Please help improve it to make it understandable to non-expertswithout removing the technical details.Choosing the Right Type of Fan The only tricky thing about purchasing a fan is finding which style you need.
Electric fans come in a range of styles and sizes, but most fans used in home or commercial settings utilize the same basic technology, with axial fans being the most common.
Centrifugal (radial) fans; Mixed flow fans; Cross flow fans; The pressure head of different types of fans with equal periphery speed of the wheel are compared in the capacity diagram below: Centrifugal fans with forwarded blades are suited for application with higher air flow volumes and pressures.
Apr 05, · I love meeting all my fans but sometimes you cuties can be a bit crazy (just like mama unicorn!). Check out part two of types of fans! Thanks for watching and don't forget to keep smiling =D!
Style-wise, most industrial fans utilize the same technology as standard portable models, and they also come in a range of different styles. However, what makes an industrial fan different from any other portable electric fan is the fact that it's usually larger and can support higher CFMs without the vibrations of a smaller household fan.
This type of fan is used in a wide variety of applications, ranging from small cooling fans for electronics to the giant fans used in wind tunnels.
Axial flow fans are applied in . Energy Star-rated ceiling fans are available in standard and low profile options like other fans, but these types of fans can save you a lot of money in the long run and are exceptionally better for the environment than other comparable units.