Owner: Lac Qui Parle County
Location: Madison, MN
Architect: Collaborative Design Group
Program: Courthouse facility and offices for multiple county
departments including county auditor/treasurer, county
recorder, county assessor and county correction.
Size: 19,000 sq. ft.
Construction Budget: $900,000
Geothermal Well Field cost: $150,000
Payback: 14 years
Steen was asked to provide engineering expertise to explore a new HVAC system replacing an outdated, inefficient system for the historical courthouse facility. The project was split into three phases, starting with a system study and including energy and life cycle analysis to develop a short list of potential options for replacing a system that was beyond its life expectancy. Creative problem solving allowed a geothermal system to be implemented, reusing most of the existing duct distribution which mitigated disruption of the occupied, historical spaces.
An insulated mechanical room located in the attic housed most of the heat pumps, strategically suspended to preserve the acoustically sensitive courtroom and office areas below. The 35 ton geothermal field consisted of 48 vertical heat exchangers, each 200 feet deep, located in the adjacent lot. A new high efficiency boiler plant also supplemented the heating system, including a Heat Recovery system that preheats required ventilation.