Multi-family Central Heat Pump Water Heating
A simpler path to hot water electrification
Domestic hot water is one of the most important energy loads in multifamily housing. In apartment buildings, affordable housing, senior housing, student housing, and mixed-use developments, hot water must be reliable every day, for every resident.
As building teams move away from gas-fired systems, the challenge is not simply choosing efficient equipment. The challenge is delivering a complete central domestic hot water system that can be designed, installed, commissioned, monitored, and supported with confidence.
WaterDrop Systems provides factory-built central CO₂ heat pump water heating systems for multifamily buildings. Our approach brings heat pumps, thermal storage, piping, pumps, valves, controls, and monitoring together into a coordinated domestic hot water plant. By moving major system integration into the factory, WaterDrop helps reduce the field complexity that can come with custom site-built central DHW systems.
For developers and owners, that means a clearer path to all-electric domestic hot water. For engineers, it means a more complete system platform to specify. For contractors, it means less custom rooftop assembly and fewer disconnected components to coordinate in the field. For operators, it means better visibility into how the system performs after occupancy.
Why WaterDrop Fits Multi-Family Buildings
Central heat pump water heating performs best when it is treated as a system. Multifamily DHW performance depends on storage volume, recovery capacity, recirculation, temperature maintenance, controls, occupancy patterns, commissioning, and long-term monitoring. WaterDrop is designed around those realities.
A WaterDrop Skid System can help multifamily project teams:
-
Reduce custom field assembly
-
Simplify coordination between trades
-
Support centralized all-electric DHW design
-
Use CO₂ heat pump technology for high-efficiency hot water production
-
Incorporate thermal storage and load-management capability
-
Improve commissioning and performance visibility
-
Create a more repeatable path for future multifamily projects
Field-tested in
Multi-family Housing
A CalNEXT field demonstration evaluated packaged central CO₂ heat pump water heating systems installed at two neighboring seven-story multifamily buildings in Menlo Park, California. The studied WaterDrop Skid Systems served central domestic hot water loops in buildings with approximately 56 homes per building.
The study found that, under representative full-occupancy conditions with appropriate commissioning, the well-commissioned system achieved an annual system COP of 2.9, reduced greenhouse gas emissions by 86%, and improved total system benefit by 61% compared with a code-minimum natural gas baseline.
The study also demonstrated load-shifting potential, with the best tested schedule shifting 52% of energy out of peak hours.
The Menlo Park project also reinforced a practical lesson for multifamily electrification: central DHW systems need coordinated design, commissioning, and monitoring. The factory-built approach helped simplify installation, and field data from the study is now helping inform improved product design, re-circulation balancing, temperature-setting visibility, commissioning practices, and load-shift controls.
Built to Reduce Project Risk
Multifamily hot water electrification should not require every project team to rebuild a custom central plant from scratch. WaterDrop gives developers, engineers, contractors, utilities, and operators a more repeatable way to approach central heat pump domestic hot water.
WaterDrop helps make multifamily DHW electrification:
-
Easier to design
-
Easier to coordinate
-
Easier to install
-
Easier to commission
-
Easier to monitor
-
Easier to repeat across future projects
