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.