This Central Heat Pump Water Heater (CHPWH) Design Guide—developed by Ecotope for Energy Trust of Oregon—is intended to help consulting design engineers become familiar with how to design CHPWH systems in commercial buildings, in particular multifamily and other multi-tenant residential uses. It gives an overview of different system configurations commonly used in multifamily residential building installations today, including pros and cons of each system configuration and the effect on overall energy usage. It also identifies publicly available design tools, covers products currently on the market, and includes case study references.
Current energy codes and standards are pushing for the adoption of more energy-efficient, load-flexible electric solutions to building energy usage. Heat pump water heaters (HPWH) are a key technology identified to meet carbon reduction and climate goals. They have the potential to reduce the energy used for water heating by a factor of approximately three, if properly designed. In addition to overall energy savings, HPWH systems naturally allow for load shift capability. A typical HPWH system is designed with less heat capacity and more storage than a traditional electric or gas water heating system. The high storage volume makes CHPWH systems available for load shift and demand response scenarios.