Geothermal.contractors

W.H. Demmons, Inc. is a Portland, Maine mechanical contractor and engineering firm founded in 1914, with over three decades of active geothermal system design and installation. The company's first geothermal project, a 22,000-square-foot building for Catholic Charities in Portland, was completed in 1992 and remains in service today. In 2014, W.H. Demmons engineered and installed a geothermal HVAC system for the CEI Office Building — a 20,000-square-foot Platinum LEED facility served by three standing-column wells each approximately 1,200 feet deep. Additional completed projects include the York County Courthouse (2006) and the Seashore Trolley Museum Model Railroad Building. The company employs professional engineers who conduct hydro-geological assessments and design standing-column-well and closed-loop systems for commercial and institutional clients. W.H. Demmons serves Maine and New Hampshire and provides engineering services nationally. Verified active operator per https://whdemmons.com/areas-of-expertise/geothermal-systems/ + https://whdemmons.com/about-us/project/cei/ (new import research 2026-05-28)