We're the Geothermal Experts in Grinnell! At Sherman Co. LLC, we specialize in WaterFurnace geothermal heating and cooling systems. Grinnell residents know we provide... the top geothermal systems in the industry today finest geothermal installation and service the kind of support that helps them recognize the complete comfort and energy-savings anticipated from a geothermal system (Our Geothermal Savings Calculator will suggest potential monetary savings. We believe you like what you see!) In Grinnell, Iowa, we're by far the best the geothermal heating and cooling contractor to call. Contact Sherman Co. LLC today.