This fume hood works permanently with a small air flow (low speed-PV) which is not sufficient to work with the fume hood open.
You must therefore press the button to increase the air flow (high speed-GV)
Attention! After 4 hours the fume hood automatically switches to low speed
The PV/GV switch is usually located next to one of the laboratory doors. It is indicated with the sign
The flow indicator is usually located at the top of the fume hood
When you turn on the fume hood, you should check that the needle is moving in the green area of the display.
Be careful not to confuse the needle (with the orange tip) with the black position indicator, a stationary pointer.
In this type of fume hood, when you decrease the height of the sash, the amount of air remains the same, but you greatly increase the velocity of air entering the fume hood.
By reducing the opening by 10 cm for example, the containment performance is greatly improved.
Remember that anything that impedes the flow of air will reduce the efficiency of the fume hood.
The green or blue QCSL 3 (Qualified for Chemical Safety Level 3) logo indicates that the containment performance has been validated for a working height of 50 cm (green) or 40 cm (blue).
All questions about the qualification of fume hoods
If you work with the sash above this height, the protection level is no longer guaranteed.
A fume hood is an open device that does not fully protect you.
Ask [email protected] if you have special activities and for any questions on user protection using fume hoods.
We introduced the qualification concept at the end of 2021.
All 900 fume hoods on the Campus will be qualified every 5 years and by 2024 they will all have been checked once. This is in addition to all the maintenance work that ensures that the fume hoods are functioning at their best according to the Swiss standard.
If you have any doubts about the level of protection provided by your fume hood in relation to your activities, contact [email protected]. For breakdowns and defects, you must contact the Alarm and Engagement Center (CAE) 34000