| So it’s no surprise engineer, Keith Hammelman, project coordinator and mechanical engineer at KJWW Engineering Consultants, was encouraged by Matt Overeem, Niles Township High Schools’ director of buildings, to use fabric duct instead of conventional metal duct in seven gymnasiums.
“With our ongoing retrofit program, we’re always on the look out for something innovative, green (ecological), or energy efficient that will help our engineers, architect (Legat Architects, Waukegan, IL), and HVAC contractors (Admiral Heating & Ventilating, Hillside, IL and Siemans Building Technologies, Mt. Prospect, IL) ‘think outside the box’” said Overeem. “So it made perfect sense to reduce our roof’s weight load with lightweight fabric duct instead using tons of steel. Fabric duct is easier to clean, it looks high tech, and it has better air distribution than round metal duct with widely-spaced registers.”
Previously the gyms—consisting of a dividable gymnastics room, dividable wrestling room, and a main gym with two balconies that are regularly partitioned off –were hot and stuffy for athletes and spectators due to outdated air handling systems that supplied and returned air from only single wall grills.
Hammelman took Overeem’s fabric duct suggestion and specified Sedona Comfort-Flow™ fabric duct from DuctSox, Dubuque, IA. This specification allows 15 percent of the air to flow through factory-engineered permeable fabric, which limits dust build-up. The other portion of airflow is dispersed gently and evenly through two linear mesh vents that run the entire length of the duct.
“With these high airflows, what you have to watch out for in large gyms is the fact that spectators and athletes get drafty blasts of air if they’re under registers on spiral or fiberglass duct, both of which we’ve used in previous applications,” said Hammelman. “With registers placed every 10 to 15 feet or so, some people get a draft and some people won’t. With the ability of fabric duct manufacturers to sew in linear diffusers along the duct—at a lower installed cost than installing linear diffusers on round metal duct--this problem is eliminated. It’s much easier to sew in a linear diffuser and the aesthetics are better.”
When considering gym duct, Hammelman notes fabric duct would be able to withstand dents from errant baseballs, basketballs and other flying objects during indoor practices.
Installation of all the gym ducts took less than a week with six-man crew, which helped keep the two-month summer time allotment for the gyms’ retrofits on a fast-track, according to Admiral’s Sam Gattuso, project manager. “I like the fact that we didn’t have to paint it and it required a short learning curve to install it,” said Gattuso.
Another advantage fabric duct has over metal duct with registers is balancing. Fabric duct needs only the assurance that the airflow through the air handler is within guidelines, which greatly reduces system balancing time.
Fabric duct also has sound attenuation qualities as well, which is important since the gyms have the dual purpose of athletic and speaking events. Air noise is lessened because of the decreased reverberation fabric offers versus metal.
“Probably the biggest savings is the lower installation costs associated with fabric duct,” Overeem added. “The fabric duct went up in a very short time at Nile North whereas if we had used metal, the sheet metal workers would still be up in the ceiling putting it together today." |