Research Project Information

Research Project Summary Information

Advanced Energy-Efficiency Hot Water Systems(ST9102A-1)

American Council for an Energy Efficient


Domestic hot water (DHW) accounts for a significant share of energy consumption in single family homes. Water heating is typically the second largest energy-use category after space heating and cooling and often accounts for $250 to $500 or more per family per year in energy costs. Real world seasonal efficiencies of most water heating systems range from 40 to 60 percent, depending on product type and application. Substantial efficiency gains, perhaps as much as 30 percentage points, would be feasible with new designs.

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Project Description

To prepare for market transformation in residential water heating, NYSERDA has teamed with California Energy Commission (CEC) and Energy Center of Wisconsin (ECW) to undertake a three year, integrated research, development, deployment, and dissemination program. Also included in this collaborative effort are the American Council for an Energy Efficient Economy (ACEEE), Lawrence Berkeley National Laboratory (LBNL), and Brookhaven National Laboratory (BNL). The project was competitively selected under the State Technologies Advancement Collaborative (STAC) solicitation which is intended to foster joint energy research, development, demonstration, and deployment (RDD&D) of technologies where common Federal and State objectives exist. The project will include the following five major tasks: (1) Develop and evaluate three promising alternative storage-type water heaters that reduce standby losses and improve seasonal efficiency; (2) Map the performance of integrated and DHW-only systems, and evaluate specific technology improvements; (3) Document infiltration impacts of gas-fired water heaters with draft hoods to identify benefits of powered-draft water heaters; (4) Improve the policy making environment for advanced water heaters through a review of test procedures, economics, and routes to market transformation; (5) Disseminate information to facilitate market transformation.


Primary benefit will be energy savings of up to 30% for water heating and associated emissions reduction. Nationwide this provides the foundation for saving one quad of energy over 20 years. Also revising the test methods will better characterize the performance of new and emerging technologies and allow consumers to make more informed decisions.

Project Results

ACEEE's role on this project was primarily information dissemination. They fostered development of the Hot Water Forum to bring industry, utilities, research groups, and government officials together to discuss the technogly as well as the associated regulations. ACEEE impacted DOE's rule making regarding hot water heaters and the regulations will now effectively mandate condensing or heat pump water heaters for units >55 gallons. ACEEE is also working with ASHRAE to modify the performance evaluation method as it is tailored toward atmospheric, storage water heaters and the benefits of condensing storage and tankless units may not be fully captured. ACEEE is also working with the industry to develop a method for standardizing performance in order to make adequate comparisons between the very different technologies.


American Council for an Energy Efficient
529 14th Street, NW Suite 600
Washington, DC 20045

Principle Investigator

Harvery Sachs

Universities Involved


Project Type:

Research Study

Technologies Types:

Building Systems
Domestic Hot Water

NYSERDA Contact Information

Nathan Russell


R&D - Buildings Research

Contract Details

Start Date: 1/11/2010
Project Status: Active
Contract Number: ST9102A-1

Last Updated: 9/15/2014