Dual-Fuel Domestic Hot Water Feasibility Study

The Northwest Energy Efficiency Alliance (NEEA) contracted with Ecotope to conduct a feasibility study of domestic hot water systems that integrate commercial electric heat pump water heaters and natural gas water heaters, primarily in multifamily buildings. The study examined the technical feasibility, gas savings potential, market opportunity, design considerations, and regulatory requirements associated with these dual-fuel systems. 

Findings suggest that dual-fuel systems can provide a practical approach to reducing natural gas consumption while helping address barriers to broader use of commercial heat pump water heaters, including high upfront costs, electrical infrastructure requirements, design complexity, and cold-weather performance considerations. The report identifies technical and regulatory considerations for implementation and presents system configurations, design practices, and operational strategies that could support wider market adoption. As a holistic evaluation of dual-fuel commercial water heating systems in the Northwest, the study provides a foundational framework to inform future market development and stakeholder engagement.