Green Campus Initiative
Green Campus Initiative is an Environmental Health and Safety program to help reduce the energy footprint of the University as well as to improve safety and sustainability on campus. We are gathering preliminary data to assess the needs of the University. Our 2012 Shut the Sash initiative reduced energy costs in the labs by approximately 43%.
- Marjorie Markopoulos, Biological and Chemical Safety Officer 937-775-2797
- Greg Merkle, Environmental Health and Safety Specialist 937-775-2217
Shut The Sash
Shut the Sash
What is it:
- Many universities have programs to lower chemical fume hood (CFH) sash heights for sustainability and safety improvements. Wright State University joined the effort in 2012. The "Shut the Sash" team took measurements on air flow, sash heights, and baseline energy costs. With this information we were able to predict and to achieve significant energy cost reductions while promoting safe lab practices.
Who was involved:
- 10 Buildings
- 5 Departments
- 61 Constant Air Volume fume hoods
- 118 Variable Air Volume fume hoods
What was measured:
- Sash Heights
- Face Velocity (Air Flow)
- Use Data (Is the fume hood in use or not?)
What Are The Benefits
|Type||Savings %||Estimated Cumulative Annual Savings $|
VAV vs. CAV
The two types of chemical fume hoods at Wright State are variable air volume (VAV) and constant air volume (CAV).
A "variable air volume" or VAV fume hood will maintain the speed (foot per minute) of the air into the fume hood regardless of sash height, but its air volume (cfm) will vary. The more open the sash, the more volume of air is needed. Since most of the air is conditioned, it must also be heated or cooled. Some studies have shown that up to 60% energy savings are possible. A true VAV system ties the fume hood exhaust with the room's air supply and exhaust.
A "constant air volume" or CAV does not adjust its air volume. The energy use and air volume (cfm) remain constant. The hood should be set up to have 80-120 fpm at 18" sash height. A lowered sash is the safest position for fume hood operations. A shut sash protects the laboratory worker from mishaps within the hood and possible hood failures.
A single CFH operating 24 hours per day uses about as much energy as 3 single family homes.
Shut the Sash
- If you have a spill in a fume hood;
- If room ventilation goes down;
- If you leave your fume hood unattended;
- If an alarm sounds on the fume hood;
- If the air flow is flowing into the lab instead of into the fume hood.
Best Fume Hood Practices
- Use a fume hood for all chemical experiments if possible.
- Do not use the fume hood for chemical storage.
- Do not lean into the fume hood.
- When in use, keep the sash opening to a maximum of 18"
- Maintain 80-120 fpm face velocity during operation
- Always work in the hood with the sash opened only as much as possible.