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Title: Disaggregating Hot Water Use and Predicting Hot Water Waste in Five Test Homes

While it is important to make the equipment (or 'plant') in a residential hot water system more efficient, the hot water distribution system also affects overall system performance and energy use. Energy wasted in heating water that is not used is estimated to be on the order of 10 to 30 percent of total domestic hot water (DHW) energy use. This field monitoring project installed temperature sensors on the distribution piping (on trunks and near fixtures) and programmed a data logger to collect data at 5 second intervals whenever there was a hot water draw. This data was used to assign hot water draws to specific end uses in the home as well as to determine the portion of each hot water that was deemed useful (i.e., above a temperature threshold at the fixture). Five houses near Syracuse NY were monitored. Overall, the procedures to assign water draws to each end use were able to successfully assign about 50% of the water draws, but these assigned draws accounted for about 95% of the total hot water use in each home. The amount of hot water deemed as useful ranged from low of 75% at one house to a high ofmore » 91% in another. At three of the houses, new water heaters and distribution improvements were implemented during the monitoring period and the impact of these improvements on hot water use and delivery efficiency were evaluated.« less
Authors:
;
Publication Date:
OSTI Identifier:
1130167
Report Number(s):
DOE/GO-102014-4397
KNDJ-0-40347-03
DOE Contract Number:
AC36-08GO28308
Resource Type:
Technical Report
Resource Relation:
Related Information: Work performed by ARIES Collaborative, New York, New York
Research Org:
National Renewable Energy Laboratory (NREL), Golden, CO.
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy Building Technologies Office
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION RESIDENTIAL; RESIDENTIAL BUILDINGS; ARIES; BUILDING AMERICA; DOMESTIC HOT WATER; DHW; DISTRIBUTION SYSTEMS; HOT WATER WASTE; DISAGGREGATION; TANKLESS WATER HEATER; ENERGY; PLUMBING; Buildings