Paper Conference

Proceedings of Building Simulation 2017: 15th Conference of IBPSA


Development of Realistic Water Draw Profiles for California Residential Water Heating Energy Estimation

Neal Kruis, Bruce Wilcox, Jim Lutz2, Chip Barnaby
1Big Ladder Software
2Hot Water Research

Abstract: Accurate estimation of domestic water heating energy use is critical to driving homes towards zero net energy (ZNE). Traditional approaches rely on estimating water heating energy by time of day by following an average daily profile, typically on an hourly basis. However, hot water draws tend to be short duration, high volume events that can cause water heaters to operate in recovery mode where the heaters are less efficient. New hot water event draw profiles are defined based on analysis of a large data set of measured draws from more than 700 California single-family homes. The draw data is processed to determine a set of representative days that reflect the same hourly average draws and same end-use sub-total volumes as the overall data set for six occupancy levels (1, 2, 3, 4, 5, and 6+ person homes) and three day types (5 weekdays, 2 weekends, and a holiday). This analysis is performed specifically for the purposes of California code compliance calculations, but the methodology may be generalized for other applications.
Pages: 876 - 884