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QUIET IN THE LAB of supplying only one-third of the needed make-up air. There were three key objectives for the pilot project: reduce noise level, correct the non-functional VAV operation of the exhaust system, and reduce energy consumption. MAKING IT WORK. The main project of installing the VAV remedy at Armstrong Atlantic State University was started in May 2011 and wrapped up in late November. Through the course of the seven-month project, the biggest challenge the team encountered was making modifications to an occupied building. School was in session for much of the project. One by one, the lab rooms were transformed. Small fans were removed, and decade-old airflow devices and lab controls were replaced with high-speed venturi valves. Big fans and sound attenuators started to populate the flat roof, and sound baffles were hung from the ceilings. Meeting of the Minds With repair and renovation funds from the Board of Regents Facilities Office, the University embarked on a test project to see if retrofitting the entire building was fi nancially feasible. A single-laboratory pilot project began in 2006. Faircloth assembled the ideal team. Chuck Hanning, P.E., was chosen to design the system. Hanning is senior mechanical engineer at Rosser International, an Atlanta-based architecture and engineering fi rm. 40 Atlanta-based Thermal Recovery Systems (TRS) contributed to the design and supplied many of the system components. TRS is a commercial and industrial manufacturer's rep firm that has served Georgia for over 30 years. Mock Plumbing and Mechanical was the contractor of choice, based on their prior work for the University. The test project would be General Chemistry Lab 2102. Originally, the 1,450-sq.-ft. room was equipped with a dozen constantvolume fume hoods, cantankerous controls, and a terminal unit that was capable COLLEGE PLANNING & MANAGEMENT / FEBRUARY 2013 Loud and Inefficient "While searching for the root of the problem, we learned, among other things, that the fume hoods would not modulate, the hoods lacked blank-off plates, and the fan bypass dampers were never powered," says Tim Crawford, of TRS. To comply with laboratory codes, the system needed to run 24 hours a day, seven days a week. But at the Science Center, the faulty system couldn't be turned down when the room was vacant. The Science Center's exhaust system evacuated more than enough air to fill the Empire State Building twice a day. Yes: 74,000,000 cubic feet. "Each lab room requires eight ACH when occupied, and half that when vacant, " says Hanning. "But these laboratories were getting 10 ACH around the clock." Combined, the fume hoods in Lab 2102 pulled 9,600 CFM out of the room, while the air-handling unit could only supply 3,000 CFM of conditioned air. The rest of the make-up air was drawn through transfer ducts connecting the room with the adjacent corridor. Prototype Instead of using one constant-volume fan at each fume hood, the new design called for a common fan system. On the roof, a 10-horsepower Danfoss VFD (variable frequency drive) was used to control a Hartzell exhaust fan, and ductwork was installed on the roof to consolidate exhaust from all of the fume hoods. Replacing numerous fans with one central fan immediately lowered the room's sound level. To further cut back on noise, a Kinetics Noise Control sound attenuator was used on the exhaust fan, and sound baffles were placed on the ceiling of the lab. WWW.PLANNING 4EDUCATION.COM