New cooling strategy introduces ductliner benefits to Arizona schools
In 2002-2003, the Tucson Unified School District (TUSD) is receiving nearly $72 million in state building improvement funding, much of which is being used to help convert a sizeable number of schools to A/C. According to mechanical consultant O.J. Clayton, principal and owner of Clayton Engineering and Consulting in Tucson, A/C will eventually become the standard cooling system in most Tucson schools. "And with so many schools going to year-round schooling and public interest growing in improving students' learning environments, it's inevitable that all qualifying schools will be making the changeover," he said.
Duct liner plays key role in conversionsNaturally, this movement to A/C systems has kept local mechanical contractors extremely busy. They have been working on the conversion to A/C in approximately 40-plus schools in the district, as well as the installation of A/C systems in new schools under construction. Qualified Mechanical Contractors, Inc. has handled much of the work, including the HVAC systems in two schools that opened last fall: Laura Nobles Banks Elementary School and Henry "Hank" Oyama Elementary School. The firm worked with general contractor Richard E. Lambert Construction.
Qualified Mechanical specified the use of CertainTeed ToughGard(tm) Duct Liner with Enhanced Surface within the air distributions systems. Each school used approximately 11,000 sq ft of the 1-in.-thick, 1 1/2-lb.-density, and moisture-repellent fiberglass duct liner. According to Nick Nieto of Richard E. Lambert Construction, it is the only duct liner he uses in his 4,500-sq-ft shop because of its consistency and the low dust level generated during fabrication.
And with concerns about IAQ at the forefront, Nieto chose ToughGard for its resistance to tearing, puncturing, and surface wear during installation and cleaning. "I'm here for the long run and know that air quality issues will be coming up," he said. "The moisture-resistant, enhanced surface upgrade is another safeguard to preserving the integrity of the insulation, especially during our humid monsoon season." Mechanical consultant Clayton agreed, adding that Tucson-area humidity levels have been rising in recent years.
Added benefit: quieter classroomsStudents in the TUSD schools will benefit from the conversion to A/C for another reason: quieter classrooms. "With evaporative cooling, air movement must be very high, so you have a problem with loud air rush noise," Clayton explained. "In my opinion, this is another obstacle to our students learning in the classroom." In fact, the U.S. General Accounting Office found duct system noise in our nation's schools is a frequent complaint of school administrators.
With the changeover to A/C systems with insulated ductwork, systems will operate more quietly, with air movement at a lower velocity and the ToughGard keeping down acoustical levels further to their lowest practical levels.
Many students will benefit from Tuscon's conversion project. The school district encompasses more than 100 schools, serving more than 61,000 students. More than 3,700 teachers, 3,600 support staff, and 200 administrators work within the system.ES