U.S. Department of Energy Energy Efficiency and Renewable Energy

Side-by-Side Testing of Water Heating Systems: Results from the 2009-2010 Evaluation

The performance of seven differing types of residential water heating systems was compared in a side-by-side test configuration over a full year period. The Hot Water System Laboratory (HWS Lab) test facility at the Florida Solar Energy Center (FSEC) in Cocoa, FL was used for the tests. Simultaneous hot water draws occur on a daily basis for the following hot water heating systems at the HWS facility with the evaluation of two draw profiles:

  • Standard electric resistance 50-gallon tank
  • Solar flat plate collector (40 ft2) connected to an 80-gallon storage tank with temperature differential controlled pump – direct loop circulation
  • Integrated Collector System (ICS, 32 ft2) connected to a standard 50-gallon water heater
  • Solar Flat Plate collector (40 ft2) connected to an 80-gallon storage tank with photovoltaic pump – direct loop circulation
  • Standard residential 40-gallon natural gas water heater tank (storage upright vented type)
  • Natural Gas tankless water heater
  • Electric tankless water heater
United States
June, 2010
Resource Type
Resource Source
Carlos J. Colon, Danny S. Parker (Florida Solar Energy Center)
e-fsec-cr-1856-10.pdf5 MB