GLENSIDE, PA. — Arcadia University located in the Philadelphia suburbs has been through plenty of changes since its founding in 1853. It has made the transition from seminary to college to university, while moving twice and changing its name once (from Beaver College). It now serves more than 4,000 students pursuing more than 80 different fields of study.
That the university has always looked back to its history and traditions is symbolized by the historic Gray Towers that rise like castle ramparts from the center of campus. That it looks ahead to the innovations of the future can be seen in the new 62,000-sq.ft. addition to its student commons area.
The addition built by GC Delran Builders includes offices, classrooms and an expansion of the university’s athletic center. It incorporates the latest in sustainable and energy-efficient technology, including geothermal heating and solar power. Principle construction began in 2010 and was completed at the beginning of 2012.
Powering the system is a geothermal field, drilled and installed by Kocher Geothermal Services and designed by Pennoni & Associates. At a point after making test bores and assessing the field’s thermal capacity, Rehau offered Pennoni & Assoc. a revised design, using a double-loop configuration and the company’s Raugeo PEXa pipe instead of HDPE pipe.
“The original design called for 50 boreholes at 450-ft. deep,” explained Bob Mellowhusky, a design engineer working for Pennoni & Assoc. “The double-loop design uses just 42 boreholes at 300-ft. depth to produce the same thermal capacity” — a savings of nearly 20%.
“The PEX pipe is definitely more flexible than the HDPE pipe,” said Jake Kocher of Kocher Geothermal, “and the fittings are very quick to make.” The Rehau system also allows the individual boreholes to be isolated on the manifold, making it easier to balance and control the system. Kocher Geothermal installed more than 50,000 feet of 1-in. PEXa pipe and 17,000 feet of 1.25-in. pipe.
Madsen Mechanical, a 60-year-old company headquartered in Broomall, Pa., installed the mechanical systems. Using six men in three crews, Madsen installed five Carrier in-line water-to-water heat pump/boilers hooked to the geothermal field. The heat pumps are staged back and forth to provide the system with redundancy.
The heat pumps in turn power the radiant floor heating throughout the 62,000-sq.ft. of the expansion. “We used Wirsbo PEX tubing for the floors,” explained Dave Madsen, estimator and manager for Madsen Mechanical. “We installed on top of the concrete floors, then poured two inches of Gypcrete on top of the whole thing. We used several circulators, but mainly the Armstrong brand.”
Madsen Mechanical also installed Aeon hot water/chilled water rooftop units, as well as doing extensive exhaust work, including installing a kitchen exhaust and makeup unit from Captiveair and a Greenheck energy recovery ventilator. “Air balancing with the outside air was a difficult problem to overcome,” explained Madsen.
Madsen Mechanical installed Honeywell controls to run the entire system, integrated with the campus’ JACE and Datamatrix building automation systems. The system can be monitored, alarms set for varying conditions, maintenance scheduled, all from within a browser window.
Complementing the mechanical systems is a rooftop photovoltaic array that provides a major portion of the building’s electricity, including the pumps and circulators used by the geothermal system. All told, the project was designed to achieve LEED Silver.
“The occupants moved in before Christmas 2011,” said Madsen, “and we were in there commissioning and adjusting things until about February of this year.” So far, students are enjoying the comfort of their new radiant floors.