The energy and cost savings potential of HPWHs as replacements for gas and electric WHs is examined in this paper. This study demonstrates the regional variations in the efficiency and economic viability of an HPWH across the continental United States for several installation locations.

Prepared by:  National Renewable Energy Laboratory

Published:  July 2013

Since its launch in 2009, the ENERGY STAR® water heater program has given consumers independent validation of water heater efficiency claims and has helped manufacturers, distributors, plumbers, and retailers promote these products.

Prepared by:  ENERGY STAR®

Published:  September 2010

This consumer-facing web page offers overviews of different types of water heaters along with efficiency information and a product finder tool, among other resources.

Author: ENERGY STAR

Annual unit shipment data collected by the EPA for the ENERGY STAR Program from program partners and/or representative associations, used to project the market penetration of ENERGY STAR certified products. Reports for calendar 2010 to 2015 are available.

Prepared by:  ENERGY STAR®

Published:  2010-2015

The purpose of this project is to verify or refute many of the concerns raised by utilities regarding the ability of large tank HPWHs to perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services.

Prepared by:  Pacific Northwest National Laboratory

Published:  March 2015

Bonneville Power Administration partnered with the Electric Power Research Institute (EPRI) and Snohomish County PUD to be part of a national demonstration pilot for integrated heat pump water heaters (HPWH). 11 public utilities were selected to participate in this field test, which grew to 14 utilities.

Prepared by:  Bonneville Power Administration

Published:  October 2012

Performance Research Type:  Research Study

This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. Laboratory results demonstrate the efficiency of this technology under most of the conditions tested and show that differences in control schemes and design features impact the performance of the individual units. These results were used to understand current model limitations, and then to bracket the energy savings potential for HPWH technology in various US climate regions. Simulation results show that HPWHs are expected to provide significant energy savings in many climate zones when compared to other types of water heaters (up to 64%, including impact on HVAC systems).

Prepared by:  National Renewable Energy Laboratory

Published:  February 2012

This HPWH demonstration examines the overall performance of HPWHs installed in a conditioned space with a number of supply and/or exhaust ducting configurations, as well as the interactions between the HPWH and the home's heating/cooling system.

Prepared by:  Pacific Northwest National Laboratory

Published:  July 2014

Using the measurement and verification (M&V) plan developed by Ecotope to assess heat pump water heaters (HPWH), the AO Smith Voltex was evaluated at the National Renewable Energy Lab. This report is the third of three preliminary assessments of three different equipment models.

Prepared by:  Bonneville Power Administration

Published:  July 12, 2011

Using the measurement and verification (M&V) plan developed by Ecotope to assess heat pump water heaters (HPWH), the Rheem Hybrid HP50 was evaluated at the National Renewable Energy Lab. This report is the second of three preliminary assessments of three different equipment models.

Prepared by:  Bonneville Power Administration

Published:  July 12, 2011