Chemistry Safety Cabinet
Airfoil – Shaped or streamlined member at hood entrance designed to enhance movement of air into the hood.
Air volume – Rate of airflow, normally expressed in cubic feet per minute (CFM).
ASHRAE – American Society of Heating, Refrigerating, and Air Conditioning Engineers.
Auxiliary air – Supply or makeup air delivered external to the chamber of a fume hood to reduce air consumption.
Baffle – Panels located across back of hood interior, which control pattern of air moving through the hood.
Blower – Air moving device (or fan) consisting of motor, impeller, and scroll.
Bypass – Compensating opening that helps maintain constant volume exhaust from fume hood, regardless of sash position.
Canopy hood – Ceiling or wall suspended ventilating device for non critical use with heat, water vapour, odors, etc.
CMF – Cubic Feet per Minute, a unit of measurement of air volume.
Combination Sash – Horizontal panels in a vertical rising frame; see sash.
Constant Volume – Type of fume hood exhaust system that exhausts the same volume of air, regardless of sash position.
Containment – Extent to which fumes are confined within the hood compartment.
Damper – Device installed in duct to control air volume.
Demonstration hood – Fume hood with glass panels on two or three sides to improve visibility for demonstrating experiments in a classroom setting.
Exhaust volume / parameters – Quantity of air exhausted by the fume hood; quantity of air required to maintain desired face velocity, expressed in cubic feet per minute (CFM).
Face velocity – Speed of air moving into the fume hood through the face opening (through the sash), measured in feet per minute (FPM).
FPM – Feet Per Minute; measurement of air velocity.
Liner – Fume hood interior sides, back, and top, including baffle.
Lintel – Portion of fume hood front located above access opening.
Louvers – Slit-like openings in the lintel that allow bypass air to enter the hood when the sash is closed.
NFPA – National Fire Protection Association.
Negative Pressure – Pressure lower than one atmosphere.
Positive Pressure – Pressure higher than one atmosphere.
Restricted Bypass Fume Hood – Fume hood operating type, designed with limited bypass area; commonly used in conjunction with Variable Air Volume (VAV) exhaust system and restricted sash opening designs.
Sash – Sliding glass panel set in the fume hood face that provides access to the hood interior.
Service Fitting / Plumbing – Water faucets and gas valves mounted on or fastened to the fume hood.
Static Pressure – Air pressure, or resistance, in fume hood or duct, expressed in inches of water.
U.L. 1805 – Underwriters Laboratories certification that verifies conformance to electrical, mechanical., and airflow standards.
Variable Air Volume (VAV) – Type of fume hood exhaust system that typically maintains constant fume hood face velocity by adjusting blower motor speed or a balance damper in response to changes in sash position.
Velocity – Speed of air, measured in Feet Per Minute (FPM).
Velocity Pressure – Force per square inch applied by moving air.
Volume – Quantity of air, usually measured in Cubic Feet per Minute (CFM).
Work surface – Top material; area in fume hood where apparatus rests and where work takes place.
