Diagram of absorption heat pump water heater.

Diagram of absorption heat pump water heater.

Photo credit: Oak Ridge National Lab

Lead Performer: Oak Ridge National Laboratory - Oak Ridge, TN
-- General Electric - Louisville, KY
-- SRA International - Knoxville, TN
-- University of Florida - Gainesville, FL
-- Purdue University - West Lafayette, IN
-- Ionic Research Technologies, LLC - South Bend, IN
-- Yankee Scientific - Medfield, MA
DOE Funding: $2,870,000
Cost Share: Provided by CRADA partners
Project Term: October 1, 2010 - September 30, 2015

Project Objective

Oak Ridge National Laboratory (ORNL) is developing and promoting the market introduction of a residential absorption heat pump water heater that would use 40% less energy annually compared to a baseline minimum efficiency unit. These water heaters greatly boost water heater efficiency by transferring heat to the water from fuel and ambient air. However, absorption technology faces the barriers of high first cost and working fluid challenges. Absorption technology could result in naturally ventilated gas-fired water heaters that achieve an energy factor exceeding 1.0. This product can contribute to the 60% water heating energy savings required to meet the Building Technologies Office’s goal of reducing building energy use by 50% by 2030. 

Project Impact

According to ORNL, the technology has the potential for 40% energy savings over other gas-fired water heaters. Fully deployed, this would provide up to 0.45 Quads of primary energy savings per year. Additionally, this would be using nontoxic working fluids with zero global warming potential and zero ozone depletion potential.


DOE Technology Manager: Tony Bouza
Performer: Kyle Gluesenkamp, Oak Ridge National Laboratory

Related Publications

Photo of a Heat Pump Water Heater.