The Church of St. Joseph’s is an established parish since the 1850s with a K-8 school located in Rosemount, MN. In 2007, with financing in place and approval from the Archdiocese, the church began construction on a new 44,000 square foot addition to their existing building to house their education program.

The project was originally under design using conventional gas-fired/ DX mechanical systems. However, the church pastor had a passion for GeoExchange systems based on his experience with these systems in North Dakota. In turn, the project architect introduced TRAK International to present its GeoExchange system to the construction team. This system uses central plant hydronic (water-to-water) heat pumps, with four-pipe individual zone fan coil arrangements and various energy recycling components.

The energy-efficient TRAK International GeoExchange system consists of ground source heat pumps, hydronic solar panels, energy recovery coils, bore-field, and a building management system.

Two 60-ton hydronic heat pumps were implemented to provide simultaneous heating and cooling to zone fan coils. One 10-ton hydronic heat pump with a double-wall heat pump and exchanger was used to provide domestic hot water for the building. Forty hydronic solar panels provide either “free” direct heating, source heat for the heat pumps, or recharging of the ground loop depending upon which control sequence is initiated. The heat pumps are custom designed for each project by TRAK and were manufactured at Midwest Fabrication and Supply (MFS), located in Zumbrota, MN.

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Each fan coil has a TRAK Energy Device (TED box) that incorporates incoming hot and chilled water supply piping and supplies outgoing piping to the fan coils. The TED box switches the system from heating to cooling based upon inputs from the zone temperature control sensors. Two heat recovery coils are in the building relief air streams to capture energy from the warm air before it leaves the building. The heat recovery coils can be used to blow off system heat if needed to maximize the efficiency of the system as a whole. Harris Companies modelled the Mechanical Room in 3D and sent the information to MFS for full prefabrication of the Mechanical Room piping. 

Six circuits of ten geoexchange boreholes each compose the ground loop capacitor. Each hole was drilled approximately 165’ deep. The location and orientation provided many challenges due to possible future expansion.

The TRAK system incorporates the use of a KMC building automation system that operates the heat pumps, air handling units, fan coils, and several control valves to direct heating or cooling fluid and distribute the recycled energy for maximum system efficiency and performance. This web-enabled system allows the operations staff to view their system's operational performance from any place at any given time.