Strategy Guideline: Proper Water Heater Selection
This Strategy Guideline on proper water heater selection has been developed to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads. These procedures, developed both for individual water heater applications (both single and multi-family) and multifamily central systems, provide users with projections on operating cost savings over a 10- year time horizon for retrofit applications and on a cash flow basis for new construction. The savings information, combined with installation cost estimates, allows one to determine which alternatives make sense for a particular application. The information presented in this guideline is based on latest monitoring results from residential field assessments of advanced gas water heater systems and heat pump water heater (HPWH) systems. The methodology presented here can be further refined as more data becomes available on emerging water heating technologies. The tool is targeted at both single and multifamily new and retrofit applications. The intended audience includes: • Builders and Building Owners • Plumbers • General Contractors • Homeowners. This guideline fills an important need because it moves beyond a simplified approach of comparing alternative water heating systems based on a single performance metric. By recognizing the load variations on equipment performance, climate differences, and retail fuel rates, one can develop a more customized performance assessment of competing technologies. This guideline represents the first step in the process of developing a comprehensive system-based evaluation of optimal water heater system design, which will hopefully be developed in the near future. Other Building America-sponsored activities will lead to measure guidelines that focus on technology-specific implementation details related to installation issues in new and existing homes. These guidelines will address issues related to combustion air, venting requirements, space conditioning impacts, safety issues, and other implementation details. The CARB team has developed such a guideline on HPWHs, entitled “Heat Pump Water Heaters in New and Existing Homes”, and IBACOS is in the process of finalizing a tankless water heater guideline.