This report was .prepared as an account of work sponsored by an agency of t h e United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes a n y legal liability or responsibility for t h e accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of t h e United States Government or any agency thereof. DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. Preface ' The federal government A the largest single energy c o m e r in L e United States with consumption of nearly 1.5 quaddyear of energy (1 quad = 1015 Btu) and cost valued at nearly $10 billion annually. The U.S. Department of Energy's (DOE) Federal Energy Management Program (FEW) supports efforts to reduce energy use and associated expenses in the federal sector. One such effort, the New Technology Demonstration Program (NTDP), seeks to evaluate new energy-saving U.S. technologies and secure their more timely adoption by the U.S. government. Pacific Northwest Laboratory (PNL,)(a) is one of four DOE laboratories that participate in the New Technologies Demonstration Program, providing technical expertise and equipment to evaluate new, energy-saving technologies being studied under that program. I This interim report provides the results of a field evaluation that PNL conducted for DOEREMP and the U.S. Department of Defense @OD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of a candidate energy-saving technology-a hot water heater conversion system to convert electrically heated hot water tanks to natural gas fuel. The unit was installed at a single residence at Fort Stewart, a U.S. Army base in Georgia, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research &d Development Agreement (CRADA) were Gas Fired Products, developers of the technology; the Public Service Company of North Carolina;