The horsepower required for any fan or blower varies directly as the  _______ of the speed, provided that the area of the discharge orifice remains unchanged.

Capacitor motors that are connected directly to fans or blowers are usually arranged to operate at one speed.

Total pressure of a fan is the rise of pressure from fan outlet to fan inlet

Power input of a fan is expressed in horsepower and is measured as horsepower delivered to the fan shaft

Which of the following motor is very efficient and is used in direct drive applications:

Wall fans are predominantly of the _______ type, since they operate against little or no resistance.

Hood exhaust fans involving ductwork are predominantly ______ , and are used especially in handling hot or corrosive fumes.

Which of the type of fans are somewhat lighter and require considerably less space.

______ efficiency of a fan is the mechanical efficiency multiplied by the ratio of static pressure to total pressure

In large industrial installations (mechanical draft fans required), which of the following motors are used for attaining different speeds:

Which of the following factors are considered for selection of motors: (multiple answer question)

Velocity pressure is the backward force of air within a duct.