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Constructed in 1972, the Bonners Ferry apartment complex provides long-term affordable housing across three buildings with 18 total units. When the current owners acquired the property in 2021, they prioritized energy efficiency, first upgrading windows and then tackling domestic hot water – a known pain point for residents who frequently reported inconsistent hot water.

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To address these challenges, the owners worked with a local plumber to install SANCO2 GS4-45HPC heat pump water heater systems in each building. The existing 55-gallon electric resistance tanks were left in place as “swing tanks,” ensuring residents had sufficient hot water while shifting most of the demand to the new, high-efficiency HPWHs.

The system design leverages the SANCO2’s ability to operate in extreme cold (down to -20°F) while incorporating freeze protection controls, insulated pipes, and heat trace tape for reliability. The electric resistance tanks serve as backup, trimming heat on the coldest days to guarantee consistent service.

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The retrofit brought measurable improvements for both residents and building owners:

• Resident Satisfaction
  ‍With the new systems, residents’ earlier complaints about inadequate hot water have been resolved, creating greater comfort and trust.
• Energy Savings
  ‍Each HPWH carried 89–98% of the hot water load, achieving winter coefficients of performance (COPs) between 1.8 and 2.3. The systems are expected to save 23,900 kWh annually – equivalent to $1,960 in electricity costs.
• Financial Viability
  ‍The $37,231 project received $19,812 in rebates from the City of Bonners Ferry and Bonneville Power Administration, reducing the owner’s payback period to just 9 years.

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This project exemplifies how HPWHs can be scaled in multifamily affordable housing – a sector often overlooked in energy efficiency upgrades. By integrating new technology with existing equipment, the owners were able to reduce energy costs, increase comfort, and successfully navigate rebate programs.

As more communities look for cost-effective strategies to modernize older buildings, projects like Bonners Ferry highlight the role of HPWHs in balancing energy efficiency, equity, and reliability. D+R International is proud to support these efforts by bringing together technology, program expertise, and real-world implementation.

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In addition to our case study work, we’re developing short educational videos on emerging energy topics. Keep an eye out in the next month for new releases on artificial intelligence (AI) in the energy sector and the role of virtual power plants (VPP) on grid stability.