Blade Dampers vs. Venturi Valves

The Armstrong Atlantic State University (AASU) Science Center in Savannah, Georgia is a 126,000 square foot building that has 36 laboratories, classrooms and offices.

As a VE (value engineering) option after the bid, blade dampers were used to control airflow in the labs in lieu of venturi valves.

After construction wrapped up in 2001, the building’s VAV (variable air volume) exhaust and HVAC equipment became an immediate problem for the occupants. The ambient noise level in the laboratories was 72 dBa, and the system was anything but VAV. The 78 fume hoods in the Science Center ran at 100% all of the time and instead of running at 8 Air-Changes per Hour (occupied) and 4 ACH (unoccupied), the labs were operating at 10 ACH around the clock. The building accounted for 40% of the campus energy usage!

The combination of noisy classrooms and financial strain finally lead AASU to make a change in 2006. They started with a single pilot room. Thermal sensors on the fume hoods were replaced with cable sash sensors and digital fume hood monitors equipped with emergency purge buttons were added. Zone presence sensors were installed, so each fume hood could be individually and automatically set back. The existing supply air blade dampers were replaced with Phoenix Controls 12-inch high-speed venturi valves, which helped with noise reduction. The accuracy of the venturi valves offered the exact make-up air needed; no more, no less.

With the success of the pilot project, AASU sought ARRA (American Recovery and Reinvestment Act) funding to retrofit the rest of the building. Funds totaling $1.5M were granted, and the project began immediately. The sweeping renovation would show a 36% reduction in energy consumption for the Science Center.

After the installation of the venturi valve system and sound attenuators, the ambient noise in the rooms measured 62 dBa. With the addition of sound baffles, that number dropped to 51 dBa with all the fume hoods operating at full capacity.

As AASU learned, the use of Phoenix Controls equipment can allow for a lab can be designed as both safe and energy efficient. See the full article from College Planning & Management magazine click here.

Air Equipment Company is the exclusive representative for Phoenix Controls in Kentucky and Southern Indiana. With over 20 years of experience, we are more than happy to help with design and selection of the right equipment for critical airflow applications.