LABORATORY FUME HOODS

Fume Hood Design Guidelines
*  Ductless hoods are not to be used for protection against volatile chemical or radioactive materials.
*  Filters are typically not installed within hood exhaust systems.
*  Hood fans are placed external to the building whenever possible.
*  Fume hood stacks will extend sixteen feet above any accessible working surfaces within 50 feet of the stack.
*  Exhaust capacity of the system is designed for 120 fpm face velocity at 18 inch sash height for each hood.
*  Fume hood exhaust is adjusted to 100 fpm average face velocity at 18 inch sash height for each hood.
Vertical sashes are preferred over horizontal sliding sashes.
Proper location of equipment and apparatus
*  Location of equipment and apparatus affects the airflow patterns with the hood.
*  Locate equipment as deep into the hood as practical and at least six to eight inches beyond the plane of the sash.
*  Elevate equipment 2 or 3 inches above the work surface to provide flow beneath equipment.
*  As a rule of thumb, no more than 50% of the work surface should be covered by equipment, apparatus or other bulky obstructions.
*  Power cords and cables should be run through plastic port openings and plugged in outside of the hood enclosure.
*  The vertical sash should be lowered as much as possible.
*  Raise sash to full open position for set-up purposes only.
*  Close horizontal panels on combination sashes before opening the sash vertically.
Always close the sash when not working in the hood.

What to check before using a fume hood

*  Check the hood inspection label to ensure that the hood has been tested within the last 12 months and operation was satisfactory at the time of the tests.

*  Check the alcove light switch.  It needs to be on otherwise the hood will be energy saving mode.  The flow is reduced to 50 fpm.

*  Check the hoods integrity and verify exhaust flow or face velocity.  The standard is 100 fpm +/- 10 fpm.

*  Do not place your head beyond the plane of the sash.


Rapid arm movements near the hood opening should be avoided.

1 comment:

  1. Thanks for sharing such nice blog. A fume hood is a kind of limited ventilation tool that is planned to restrict revelation to dangerous or poisonous vapors, fumes or dusts. A fume hood is characteristically a big part of tool enclosing five sides of a working area, the base of which is most generally placed at a standing work elevation.

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