IPE definitions Flashcards
FANS AND BLOWERS
The work done in moving a given volume (or weight) of air at a given speed.
Air horsepower
A fan used to force air under pressure, that is, the
resistance to gas flow is imposed primarily upon the
discharge.
Blower
The work done by an electric motor in driving the fan, measured as horsepower delivered to the fan shaft.
Brake horsepower
The physical volume of air moved by a fan per minute expressed as fan outlet conditions.
Cubic feet per minute (cfm)
The actual weight of air in pounds per cubic foot (0.075 at 70°F and 29.92 inches mercury barometric pressure).
Density
A fan used to withdraw air under suction, that is, the resistance to gas flow is imposed primarily upon the inlet.
Exhauster
A machine used to apply power to a gas in order to cause movement of a gas.
Fan
The ratio of air horsepower to brake horsepower of a fan.
Mechanical efficiency
The speed at which a fan or motor turns.
Revolutions per minute (RPM)
Air at 70°F and 29.92 inches mercury barometric pressure weighing 0.075 lbs. per cubic foot.
Standard air
The mechanical efficiency multiplied by the ratio of static.
pressure to the total pressure.
Static efficiency
The static pressure of a fan is the total pressure diminished by the fan velocity pressure. It is usually measured in inches (millimeters) of water.
Static pressure
The sum of the static pressure and the velocity pressure. Total pressure represents the rise of pressure from fan inlet to fan outlet.
Total pressure
Velocity pressure results only when air is in motion, and it is measured in inches (millimeters) of water.
Velocity pressure
