Southeast Elementary School Geothermal Studies

Project Data:
Southeast Elementary School
Ankeny, Iowa
Ankeny Community School District initiated a project to provide air conditioning and upgrade the heating, ventilating, electrical and life safety systems serving the Southeast Elementary School. The school heating and ventilating system dated back to the original building construction in the 1960’s and had reached the end of its service life.

Heating/Cooling System:
Geothermal Heat Pump with vertical bores. Individual water source heat pump units replaced unit ventilators in each classroom. Separate ventilation systems using water to water heat pumps heat and cool outside air for ventilation.

Elementary school floor area:
37,850 sq. ft.

Installed Capacity:
130 tons

Installed Heat Pumps:
41 water source heat pump units sized from 1 to 10 tons.

Geothermal Heat Exchanger:
120 vertical bores at 175 feet deep. The bore field has 10 circuits with 12 bores per circuit. The Geothermal Heat Exchanger absorbs or rejects heat to the earth and replaces the cooling towers and boiler used for conventional system designs.

Underground Piping:
Over 10 miles of high density polyethylene underground piping. Pipe sizes range from 3/4” to 2.”

Bore Field Cost:
$60,500 incremental cost over a conventional system. An energy efficiency rebate incentive was provided by MidAmerican Energy.

Annual Cost Savings:
Projected $7,500 annual cost savings for energy, operation and maintenance costs.

Payback Period:
8 years.

Benefits:
Provides heating, air conditioning and ventilation for an improved indoor environment. Reduces maintenance and operating costs.