Invention Reference Number
A compact, energy-efficient 120V (15 amp) heat pump water heater (HPWH) for seamless replacement of conventional residential water heaters has been developed. This solution addresses common barriers in retrofitting existing units – such as limited space and insufficient hot water delivery – while maintaining ENERGY STAR® performance standards. By enabling broader adoption of low-power electric water heating, the technology supports electrification goals without requiring costly electrical upgrades.
Description
This innovation focuses on maximizing hot water delivery from a unit that matches the physical dimensions of conventional 240V electric or gas water heaters, making it ideal for drop-in replacements in space-constrained environments. Leveraging a combination of proven and novel design strategies, ORNL’s approach improves heat pump efficiency and water output while operating on a standard 120V (15 amp) circuit. The system aims to meet ENERGY STAR® criteria for efficiency (UEF ≥ 2.20) and First Hour Rating (≥ 45 gallons), with additional attention to reducing installation challenges. Successful development of this unit could enable homeowners to free up panel capacity for other electric appliances, accelerating whole-home electrification without expensive infrastructure modifications.
Benefits
- Enables drop-in replacement in standard residential water heater spaces
- Reduces need for costly electrical panel or service upgrades
- Supports increased home electrification with minimal disruption
Applications and Industries
- Residential water heating electrification
- Water heater manufacturing and original equipment manufacturer (OEM) collaboration
- Retrofit installations in existing housing stock
Contact
To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051
