The mechanical fan debuted in the 1500s as the canvas c […]
The mechanical fan debuted in the 1500s as the canvas covered the so-called "double-buckle" frame hanging from the ceiling. To create the cooling effect, a rope is attached to the frame and the servant pulls the fan back and forth. Belt fans powered by factory water tankers were manufactured in the 19th century. After the introduction of electric fans, fans open to the public. Fans enhance the home's decor as they are functional and stylish, and are equipped with brass blades and cages.
The EC blower utilizes the power from the motor to generate a volumetric flow of air at a given pressure and is often considered a low pressure air pump. The propeller converts the torque (rotational force) from the motor (usually a permanent split capacitor AC induction motor or brushless DC motor) to increase the static pressure on the fan rotor and increase the kinetic energy of the air particles.
EC blower is divided into propeller, pipe shaft and blade shaft type, each type has different characteristics. Propeller fans consist only of motors and propellers and are therefore the simplest. The tube shaft is similar to a propeller, but has a venturi around the propeller to reduce vortexing. Vane axial fans are equipped with vanes behind the propeller in the airflow to smooth the eddy currents.
Flow and pressure characteristics are the main differences between fans and blowers. Although the fan delivers air in the entire direction parallel to the axis of the fan blade, the fan delivers air in a direction perpendicular to the axis of the fan. As a result, the fan can be configured to provide high flow, operating at low pressure while the blower delivers relatively low flow at high pressure. Centrifugal blowers can be squirrel-cage type with forward bend or backward bend.
Another major difference is the mechanism that limits the flow of air. In a blower, it has the opposite effect on the same motor that drives the fan blades. For example, when the motor is driving a squirrel cage blower, the load on the motor is reduced. When the system is blocked, the blower accelerates. On the other hand, as the airflow system is clogged with fan blades, the motor load increases and the fan slows down.