Water heating is the 1st to 3rd largest energy use in the typical home, the rank depending primarily on the number of people and the climate zone. As fuel prices have risen, there has been a great deal of interest in more efficient water heating. For several years, tankless water heaters, particularly natural gas, have been touted as the solution to our desire for more efficient water heating, but how well do their performance characteristics match those of our hot water use patterns? We will lay the groundwork for this topic by discussing hot water use patterns and what people want and expect from their hot water systems. Then we will compare the performance characteristics of tank and tankless water heaters, both gas and electric. While the primary focus will be on residential applications, multifamily and small commercial applications, including food service will also be discussed.

By attending this session, participants will

1.      Gain an appreciation for the relative importance of water heating compared to other energy uses

2.      Learn the basics of how tank and tankless water heaters, both gas and electric work

3.      Determine how well the performance characteristics of each water heater match typical hot water use patterns