| Airflow: |
The ability of air to move and flow in a predesigned direction by forced air or negative air pressure. |
| Axial Fans: |
Tubular airflow fans that support flexible ducting. The fan consists of propeller-like blades rotating perpendicular to the flow of the general air stream. Axial fans are usually exhaust fans often containing contaminated air that must be directed to an outside source, but axial fans properly used can be directed to pressurize atmospheres in buildings or zones. |
| Balancing by Static Pressure: |
Measurement and design of local exhaust system ducts, by selecting the duct diameters that generate static pressure to distribute airflow without dampers. |
| CFM (Cubic Feet per Minute): |
The volume of airflow calculated over one minute (60 seconds). Along with lift, the measurement of cfm is one major method of determining vacuum efficiency. |
| Comfort Ventilation: |
The desirable range of airflow, temperature, humidity and odor in a building that allows for the comfort of the building occupants. Also called the comfort zone. |
| Entrainment Velocity: |
a) The ability of water, gas, vapour, mist and solid particles to absorb and impact into other materials. b) The gas flow velocity in air, which tends to keep particles suspended and cause deposited particles to become airborne. Mitigation Note: Typically this applies to airflow in ducts carrying airborne particles and other contaminates. Entrainment velocity effects is a concern for water damage mitigation contractors who use 1,000 CFM or greater air movers which transport large amounts of wet-humidified air throughout a building. See Acceleration Velocity, Air Movement, Dynamic Pressure, Turbidity Air Currents |
| Laminar Air Flow: |
Streamlined airflow in which the entire body of air within a designated space moves with uniform velocity in one direction along parallel flow lines. |
| Retard: |
Any action, chemical or engineering control, that slows or reduces a peril in progress, such as cleanup of a water damage, dehumidification, airflow, or a chemical such as a disinfectant, in controlling microorganisms. |