LOCATION
Iowa City, Iowa

AREA
30,148 GSF

PROJECT DESCRIPTION
Iowa City Community School District’s Longfellow Elementary is an over 100-year-old building that underwent modernization renovations and an addition to accommodate a new main entrance, media center, art room, music room, and gymnasium.

PROJECT HIGHLIGHTS

• Vertical, self-contained, geothermal water source high-efficiency heat pumps with individual space control are utilized to provide space temperature control in each classroom. Support spaces use horizontal, geothermal water source high-efficiency heat pumps located above ceilings.
• A horizontal bored geothermal loop field was installed. Fifty-two 600-foot-long horizontal bores were installed to minimize disruption of the existing school site. Emergency backup heat for the ground-coupled heat pump loop is provided using an electric boiler.
• Three energy recovery units provide the code required for outside air for the ground-coupled heat pump system. The units include direct expansion cooling and hot gas reheat to dehumidify outdoor air and an electric heating coil to prevent frosting on the energy recovery unit heat transfer surface during extremely cold ambient air temperatures.
• Code-required lighting control systems were provided for interior lighting that incorporate vacancy sensors, occupancy sensors, manual dimming, multi-scene control, and automatic daylight harvesting where natural daylight is present. The interior lighting design proved to be 78% more efficient than the baseline code energy allowance, and the exterior lighting design proved to be 91% more efficient.
• Exterior lighting was controlled through a dusk-to-dawn exterior photocell wired in series with a programmable time clock within the building automation system. Exterior parking lot lighting includes bi-level control, allowing the district to reduce parking lot luminaires to 50% when desired through the building automation system.
• Energy saving strategies that were provided in the renovated Longfellow Elementary included:
  • Energy recovery unit zoning allows shut-off when areas are unoccupied.
  • Specifying heat pumps with efficiencies above minimum code requirement.
  • Energy-efficient LED luminaires with soft diffusing optical lenses and reflectors throughout the building’s interior and exterior.

You can check out more of our k-12 education experience here. 

Photography credit: Kessler Photography