- VENTILATION - Moving air from one area to another.
- CIRCULATION - The moving of air within a given area.
- CFM - The volume of air moved by a fan expressed in cubic feet per minute.
- SP / STATIC PRESSURE - The resistance to flow in any air moving system, expressed in inches of water column (IN. W.G.). Fans aerated in CFM at various static pressures.
- HP / HORSEPOWER - The most common measurement of mechanical power of a motor.
- BHP - The horsepower required to drive the fan at a given RPM and Performance Point.
- VELOCITY - The speed, expressed in FPM (feet per minute), of air moving through a given area such as a duct, face area of a hood, air intake opening or cross section of a room or booth, or from an air circulator.
- AIR CHANGES - The time required for a complete air change in given space. Normally expressed in minutes per change.