The Geothermal Name to Trust in Winterset Forgive the pride, but that would be us: Sherman Co. LLC! Winterset, Iowa, residents have been turning to us to meet their geothermal heating and cooling needs for years, now. We'd like to gain your assurance, as well. If you've been thinking of “going geothermal” but have been holding off, you can certainly trust us on this: given today's shifting economy, there's never been a better time to learn more about the savings a geothermal heating and cooling system can offer. Want facts? Do a little simple math with our Geothermal Savings Calculator. Then contact Sherman Co. LLC for the finest geothermal system installation and service in Winterset - and beyond! Oh ... and talk about trust: We install geothermal heating and cooling systems by WaterFurnace. That's a name that resounds in the geothermal industry.