Inverter ventilation fan and two-speed ventilation fan

Ventilation fans in each use case, in accordance with the requirements of the customer to design and manufacture the equipment, not the needs of customers, this is the most reasonable and most correct way.
Inverter ventilation fans are generally used for the high power requirements of the fan. Can prevent the motor starts high transient current impact on the user grid inverter motor, but also can achieve the purpose of energy saving, according to the frequency of use of unreasonable period of time the fan barrier requirements by changing the frequency to control the air volume air pressure requirements.
Two-speed ventilation fan is commonly used in special occasions, such as the exhaust fan fire usually use low-grade speed for ordinary exhaust the air supply in the event of a fire, you need to use the high speed high wind to fire smoke gas discharge. The two-speed fan is installed in a two-speed motor, the motor is usually by changing the motor winding stages, or one motor is a plurality of windings to achieve the purpose of the shift. Exhaust fan fire one machine to achieve the purpose of common two-speed the ordinary electricity connected low speed, fire electricity access high speed. Two-speed motors are generally 2/4, 4/6, 6/8 several series ratio, choose two-speed fan series based on high-speed, low-speed wind than to elect the right and two-speed motor.