Auto facility hums along with aid of duct wrap
This dual personality of the H2 will actually mirror its new manufacturing environment: a careful juxtaposition of demanding, military-like quality standards with thoughtful design elements intended to create a more pleasant work experience. The details in the AM General's new 630,000-sq-ft facility near South Bend, IN, are almost military in their precision.
From the plant-wide air pressurization systems to pre-engineered blowout panels and spark-arresting fixtures in the paint-mixing room, the plant's rigorous code of safety and quality is apparent. And one of the tools that helped make that setting possible was white PSK Duct Wrap from Knauf Fiber Glass (Shelbyville, IN). But management also understands that the factory would quickly grind to a halt without an engaged, productive workforce. A comfortable ambience was clearly the intent of architects at Albert Kahn Associates (Detroit).
A finished finish"For the person who works here everyday, it's important for the plant to look nice," said Rick Bernard, mechanical/electrical coordinator for Kahn. "If the workers aren't happy with their environment, then the product that goes out the back door is going to reflect that."
That idea applied to duct insulation as well. Knauf duct wrap with white PSK facing was selected instead of a more conventional silver foil-faced product. The insulation's white PSK facing is a trilaminate material composed of a white, metalized polypropylene film; a fiberglass reinforcing scrim; and white kraft. PSK combines a bright finish with improved resistance against punctures, tears, and moisture.
"It looks clean and bright," Bernard said. "We don't have to paint it to get a nice, shiny finished look. That saves our contractors time, and you can see the difference it makes in the atmosphere it projects throughout the plant."
About 120,000 sq ft of 2-in. Knauf duct wrap was used on dual-service supply ducts in the plant's hvac system, which includes in-line gas burners for heating and three screw-type chillers that supply 44 degrees F chilled water for cooling. Seventeen AHUs, with an average capacity of 60,000 cfm each, distribute conditioned air.
Resisting wear and tearOne important challenge for the insulation was preventing condensation on ducts during thecooling operation (55 degrees supply air temperature), a daunting task given the use of 100% fresh air during humid Indiana summers.
One of the advantages that Knauf's PSK facing provided over traditional white vinyl was a significantly lower moisture vapor transmission rating to help prevent water vapor from migrating toward the cold ducts.
The insulation also had to resist the normal abuse and wear of the jobsite. The PSK facing offers a puncture resistance rating of 25 (TAPPI Test T803, Beach Units). "The tougher the insulation, the less rework that has to be done," Bernard noted. "This system has been working nicely; I've yet to see any of it come undone or lift up." The insulation contractor, Gribbins Insulation (Evansville, IN), finished the Hummer plant project in four months, with just four crew members on site.
The duct wrap delivered durability, excellent thermal and acoustical values, easy handling attributes, and a clean look that fit the vision for the AM General facility. As Brian Willet, project manager for Gribbins Insulation, said, "Our installers like it, and it solved a design challenge for the engineers. So it turned out to be a good solution all around." ES