Electric fans are manufactured to produce a high volume and low pressure air flow. Generally, a plastic or metal fan blade will rotate in a circular motion when exposed to an air stream from the motor. There are several main types of fans used for moving air. The most commonly used fans are axial, radial and tangential.
A brief description of these fan types is as such:
Axial electric fan: is used in a wide variety of household applications. A Standard axial electric fan has a diameter of 300-400 mm or 1800 - 2000 mm. Several examples of an axial electric fan include:
- Table fan
- Ceiling fan
- Mechanical Engine Cooling fan
- Variable Pitch Fan
Radial electric fan: causes air to enter the fan at the shaft and move vertically away from the shaft to the opening in the scroll-shaped fan casing to produce air. A radial electric fan is noisier than an axial electric fan. Several examples of a radial electric fan includes:
- Leaf blower
- Blowdryers
- Air mattress inflators
- Climate control
Tangential electric fan: is used vigorously in the HVAC industry. The tangential electric fan uses an impeller with a forward curved propellers, placed in a casing consisting of a rear wall and a vortex wall.
Electric Fan Inspection and Quality Control Standards
The following are some key points which are considered for quality control and inspection of electric fans:
IEC 60335-1
The IEC 60335-1 standard deals with the safety of electrical appliances for household purposes. The rated voltage cannot exceed more than 250 volts for a single-phase appliance.
IEC 60335-2-80
The IEC 60335-2-80 Standard is used for the safety of the electric fan appliance intended for use in shops, light industry and on farms.
CE Marking
A CE marking is required to be visible on the electric fan household product to sell products in Europe, as well in order to provide evidence that the product conforms to the European Standards.
RoHS
The Restriction of the use of certain Hazardous Substances (RoHS) in electrical and electronic equipment fans must be compliant with the RoHs in order to comply with International Standards.
ASTM D4167 - 97
The ASTM D4167 - 97 Standard Specification for Fiber-Reinforced Plastic Fans and Blowers is used to comply with the minimum requirements for the manufacturing of both radial and axial fans and provides specific testing for determining safe operating speeds.
