Integration with environmental room controls is required, and the system can become out of balance without proper maintenance. In addition, sudden use fluctuations of several hoods at once (as is often the case with classroom lessons) can result in an uncomfortable room environment for a short period of time. This occurs when the building  system must suddenly supply large amounts of make-up air into the room. If it does not have enough time to properly condition the air, the room climate may temporarily shift into uncomfortable zones, particularly if the outside air is extremely cold, hot, or humid.

Inhalation is a major route of entry of chemicals into the body. Chemical fumes and vapours can directly enter our bloodstream and small particles can lodge in the alveolar region of our lungs. A properly designed and operated fume-hood reduces exposure to hazardous fumes, vapours, gases and dusts. A fume-hood confines hazardous airborne material by diluting it with a large amount of air, drawing it through an exhaust system and then expelling the air in vents locate on the roof of building 18. Proper use of the fume-hood sash can also shield the worker from an uncontrolled reaction. Fume hoods are inspected and tested annually to assess performance standards but it is up to you to use a fume-hood safely.

Fume-hoods draw air out of the rooms they are installed in. There needs to be an adequate volume of air available or the fume-hood will not be able to draw a sufficient volume of air to function properly. Where the room is small or there are a large number of fume-hoods an additional supply of air, other than the normal room ventilation, may be required. This additional air is known as the make-up air. If the make-up air supply is not adequate or the make-up air is switched off then the fume-hoods may not be able to achieve the required face velocity. This can cause fumes to escape in to the laboratory.

Automated sash closure systems detect the presence of laboratory technicians in front of the fume hood with an infrared occupancy sensor. When no occupancy is detected for a predefined period of time, the sash automatically lowers, thus reducing exhaust and make-up air using the capabilities inherent to the variable air volume system. The proposed measure aims to reduce the overall airflow through fume hoods that will result in energy savings associated with fans, cooling, and heating of the space.

The proposed measure does not include revisions to minimum face velocity requirements; rather, it saves energy by reducing area of sash opening while maintaining constant face velocity defined by health and safety standards and facility protocols. The measure is prescriptive and thus can be displaced by alternative energy savings measures through a performance approach.

Automated sash closure systems detect the presence of laboratory technicians in front of the fume hood with an infrared occupancy sensor. When no occupancy is detected for a predefined period of time, the sash automatically lowers, thus reducing exhaust and make-up air using the capabilities inherent to the variable air volume system. The proposed measure aims to reduce the overall airflow through fume hoods that will result in energy savings associated with fans, cooling, and heating of the space. The proposed measure does not include revisions to minimum face velocity requirements; rather, it saves energy by reducing area of sash opening while maintaining constant face velocity defined by health and safety standards and facility protocols.