Overview
Housing Hilltop is the Tacoma Housing Authority’s (THA) largest affordable housing development since New Salishan, bringing new housing and neighborhood-serving retail to the Hilltop community. The project includes 231 affordable housing units and 13,000 square feet of ground-floor commercial space, supporting a vibrant, mixed-use environment.
Central Heat Pump Water Heating
HVE provided plumbing engineering services for Housing Hilltop, including the complete design and controls for a centralized heat pump water heating system serving 231 residential units across two buildings.
Designed when industry experience with central heat pump water heating was still relatively limited, the system required careful coordination of heat pump equipment, hot water storage, recirculation, piping, and controls to provide reliable hot water while improving energy efficiency.
The completed system uses 34 CO₂ refrigerant heat pumps and approximately 3,090 gallons of hot water storage. Independent performance monitoring projects the system will operate about 2.5 times more efficiently than conventional electric water heating.
Featured in Industry Research
Housing Hilltop was featured in a case study published by the New Buildings Institute (NBI), examining the installation, commissioning, and performance of centralized heat pump water heating systems in multifamily housing.
While HVE was not the commissioning agent, our engineers were heavily involved throughout the commissioning process, working alongside the manufacturer, installer, and commissioning team. The case study highlights how collaboration and commissioning can help optimize the performance of these complex systems.
