Marsh Life Science has Variable Air Volume (VAV) Hoods. This means that as the fume hood sash is lifted, an air velocity sensor within the fume hood detects the change in air velocity and the air control valves modulate so the air velocity maintains 100 feet per minute (fpm) at the face of the fume hood.
Each fume hood also has a face velocity sensor with an alarm to monitor the velocity of air passing through the fume hood. This alarm sounds when a face velocity of less than 100 fpm is detected. Please do not "mute" or tape over your fume hood alarm. If the alarm sounds consistently, please notify Physical Plant to have the hood repaired.
Some air velocity alarms are also interlocked with the room's light switch. In these spaces, an alarm will signal if the sash is left open and the room lights are turned off. Always close the fume hood sash and shut off the lab lights when leaving the lab.