As the city of Verona, WI grew, the old Fire and EMS Station was removed to make room for a new complex that included living quarters. The department would expand from a 10,200 sq. ft. facility to a 41,500 sq. ft. facility, and they were motivated to reduce natural gas usage. MEP Associates, a Salas O’Brien Company, is a multi-disciplinary engineering consulting firm. They were tapped to provide HVAC, electrical, plumbing, and fire protection engineering design services. A high-level geothermal feasibility study was conducted to compare the performance of a traditional HVAC system to the proposed geothermal system. The city chose to go with a geothermal hybrid system.

The geothermal hybrid system includes a fan coil air-side system with ERV, a geothermal heat pump with a cooling efficiency of 0.761 kW per ton and heating efficiency of 4.6 COP, and a hybrid gas fired hot water boiler (rated 85% efficiency). A large portion of the square footage is heating only, as the garage space where the fire and EMS trucks are stored does not require cooling. The geothermal system meets most of the heating requirements and provides all of the cooling for the office and living quarters.