flinnsci.com SAFETY SUPPLIES & EQUIPMENT FUME HOOD ACCESSORIES
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Velometer (Vaneometer®)
SE4055, etc.
Hood Efficiency Label
SE5017
Fume Hood Accessories
Velometer
The efficient operation of your school’s fume hood is essential to the well-being of
you and your students. Used to check fume-hood efficiency, a velometer measures
air velocity with readings expressed as linear feet of air per minute.
To check hood efficiency, measure the air velocity at the “face” of the hood opening,
ideally at multiple locations across the face. A hood should provide air movement
of at least 100 linear feet of air per minute.
Easy to use, the unit must be level during use, so a bubble level is built in. The unit
is calibrated from 0 to 400 feet per minute. Accuracy is ±10%, full scale.
The carrying case is available to protect the instrument during storage.
Catalog No. Description Price/Each
SE4055 Velometer (Vaneometer®) $100.00
Hood Efficiency Label
Labels should be affixed to the posts of your
hood so that you and your students know where
the hood sash should be placed to offer the highest level of protection. Adhesive
backing; 21/2" x 1".
Catalog No. Description Price/Each
SE5017 Hood Efficiency Label $ .65
Fume Hood Considerations
HOOD SAFETY
1. Do not assume that a fume hood is operating efficiently just because you hear the
motor running. Check the hood using a velometer or a smoke generator.
2. Label your fume hood side post(s) to indicate which sash position (opening) offers
the greatest protection.
3. Position the adjustable hood baffles (if furnished) to provide the most efficient air
movement.
4. Do not use a fume hood as a storage area for chemicals or other materials.
5. Work as far under the hood as is practical and comfortable, but at least six inches
inside the hood area as a minimum.
6. To the extent possible, use the fume hood sash as a face shield. Avoid working with
the hood sash wide open.
HOOD LOCATION
1. Room drafts dramatically affect hood efficiency. Never locate a hood near
or across from a window,
door or air outlet/inlet.
2. Hoods should never be placed in heavy traffic areas.
3. Room air flow patterns will affect a fume hood, and these patterns should
be considered before permanently locating a hood.
4. Hood exhaust should be independent of other building exhaust stacks, and
the exhaust exit should be located well away from any school air inlet.
5. If multiple hoods are part of a single exhaust system, that exhaust system
must be designed so each and every hood can be operated with no influence
on others in the system.
Smoke Generators
A great and inexpensive way to monitor air movement in your fume hood or to test
the laboratory ventilation system. Once ignited, these military-type smoke generators
will allow you to safely determine if your room ventilation system operates properly
or if your fume hood efficiently moves air. Smoke generators also enable you to trace
air movement from the inside to the outside of a building. The white/gray smoke
generated is a result of a chemical reaction, so there will be no messy residue in
your lab or on your clothing. If your budget does not allow a velometer to check your
fume hood, then at least consider using a smoke generator to be sure that your hood
efficiently moves air. Two sizes of generators are available. The 30-second type will
generate approximately 4,000 ft3 of smoke. This size should be adequate to test air
movements within the laboratory or fume hood. The 3-minute generator will provide
almost 40,000 ft3 of smoke. This generator would be your choice if you wish to trace
the exhaust path from your hood or exhaust to a remote, outdoor roof stack. Sold in
packages of two generators.
Catalog No. Description
Size
(Diameter x Length) Price/Pkg. of 2
SE5010 Smoke Generator, 30-second 11/2" x 11/2" $16.35
SE5011 Smoke Generator, 3-minute 11/2" x 6" 34.30
Smoke Generators
SE5010, etc.
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