As part of a multiyear renovation, Grant Towers, which consists of four 12-story residence halls, on the campus of Northern Illinois University (NIU) in DeKalb, Ill., received complete upgrades of its mechanical systems to improve both energy efficiency and occupant comfort.
Vertical fan-coil units in two of the residence towers were replaced with 740 200- to 600-cfm-capacity Vertical Floor Series fan-coil units from International Environmental (IEC). The triangular shape of the 50-plus-year-old buildings presented a significant challenge, as it created odd exterior walls for installation. IEC’s customization capabilities were key to keeping the project on track in meeting scheduling and budgetary goals.
“Without the ability to customize the fan-coil-unit sizing, NIU would have had to go in a completely different direction with the project,” Jake Vorac, vice president of Mechanical Sales Inc. in Davenport, Iowa, said. “It would have been a ‘waterfall effect’ of sorts, impacting everything from the architectural renderings to the furniture.”
According to Vorac, each unit was required to have fresh-air-intake capabilities, something not available with standard fan coils.
“Overall energy savings was a high priority for this project, as these were some of the most energy-intensive buildings on campus,” John Flemming, mechanical engineer and project manager for Rock Island, Ill.-based KJWW Engineering Consultants, explained.
According to Flemming, the existing mechanical systems were using 100-percent outside air to ventilate indoor spaces and exhaust air up to the roof. To make distribution more efficient, he and his team specified a glycol runaround coil that would bring fresh air indoors. The coil would work in conjunction with the outside-air openings designed as part of the custom fan-coil cabinets.
“This design enabled us to distribute fresh air to all floors much more efficiently,” Flemming said.
Installation of the IEC fan-coil units was executed floor by floor.
“This was a complete tear-out job, which was efficiently managed in stages by tackling and completing one floor of the building at a time,” Vorac explained.
Based on experiences with the first tower, the project team commissioned custom aesthetic panels for the units in the second tower to cover gaps resulting from differences in size between the existing units and replacement units.
“With the renovations, the buildings now feature three dorm-room layouts, so we decided to customize fan-coil-unit designs for each room type,” Flemming said. “One 3-ft-6¼-in. unit was specified for each corner room, while two 5.2-ft-¾-in. units would be installed in the two-window rooms, and a singular 7-ft-¾-in. unit would go into the one-window rooms.”
Further customization of the cabinet designs was provided to accommodate specially developed IEC valve packages required for the unusual installations.
“We’ve seen a significantly faster installation, which translates to hard dollars and cents because we’re not waiting on any outside suppliers,” John Lauer, project superintendent for Cherry Valley, Ill.-based Ringland-Johnson Construction, said. “When you’ve got a supplier making custom units and providing components like pre-fabricated end panels, you just have to hope it’s all going to come out uniform and look intentional. IEC definitely delivered on this, and everything looks very cohesive.”
Vorac added: “I don’t think there’s another manufacturer that could have gotten this right. It was a complex job with many specials required to get it done.”
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