One is the size of the blade.
The second is the speed of the blade.
Usually, the electric fan with small blades rotates fast, while the ceiling fan with large blades rotates slowly. In terms of power, with high-power motor, the fan has a large air volume and consumes a lot of electricity. Such as industrial exhaust fans, have a large air volume.
The maximum speed is the maximum speed that can be achieved under certain conditions. Such as the spindle speed of the motor in the hard disk, that is, the maximum speed that the hard disk can reach under normal working voltage. Rotational speed is one of the important parameters to mark the grade of hard disk and one of the key factors to determine the internal transmission rate of hard disk, which directly affects the speed of hard disk to a great extent.
Extended data:
When the electric fan is working (assuming that there is no heat transfer between indoor and outdoor), the indoor temperature will not decrease, but will increase.
When the electric fan is working, because there is current passing through the coil of the electric fan and the wires are resistive, it will inevitably generate heat and release heat, so the temperature will rise. When the electric fan works, the indoor air will flow, so it can promote the rapid evaporation of sweat. Combined with "evaporation needs to absorb a lot of heat", people will feel cool.
After the electric fan is used for a long time, it is easy to get a lot of dust under the fan blades. This is because when the electric fan is working, the blades are charged with static electricity due to friction with air, and charged objects can attract light and small objects, thus absorbing the fine dust floating indoors.
Baidu encyclopedia-rotational speed
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