Research on Fixture-Level Peak Probability of Water Use in Commercial Buildings

Published

June 5, 2024

Author(s)

Tao Li, Steven Buchberger, Toritseju Omaghomi, Gary Klein, William M. Healy

Abstract

novel wireless sensor network is developed and demonstrated for monitoring indoor fixture level water use in buildings. The new technology consists of a low-cost, battery-powered, miniature wireless sensor module for non-invasive detection of flow through pipes. When deployed in a typical commercial, industrial, or residential building, the modules form a remote wireless sensor network that accurately monitors the incidence and patterns of water usage at individual fixtures. As proof of concept, the wireless sensor network was deployed and tested in a dormitory at the University of Cincinnati (UC) where several water fixtures were monitored at a 1-second interval for a period of five months. The water use data were analyzed to obtain peak period probabilities of fixture use (i.e., p-values). Fixture p-values are needed to estimate the instantaneous peak water demand in buildings, the key parameter for properly sizing premise plumbing systems. A dimensionless ramp function on the unit square is developed and demonstrated as a versatile approach to help engineers obtain reasonable estimates of fixture p-values in new buildings where water use data may be lacking or sparse. A protocol is suggested to guide investigators on how to compile, consolidate, and archive high resolution water use data into a cloud-based repository. Results include preliminary estimates of p-values for restroom fixtures in a large sports arena on the UC campus. Peak flows at the sport arena measured during five NCAA basketball game days are compared against predicted peak flows from the Water Demand Calculator. Finally, peak flow measurements at 20 large contemporary residential buildings across the US are compared against predictions of the 99th percentile from the Water Demand Calculator.

Citation

Grant/Contract Reports (NISTGCR) - 24-053

Report Number

24-053

NIST Pub Series

Grant/Contract Reports (NISTGCR)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.GCR.24-053

Local Download

Keywords

Commercial Buildings, Fixture Probability, Peak Water Demand, Wireless Sensor, Water Demand Calculator.

Citation

Li, T. , Buchberger, S. , Omaghomi, T. , Klein, G. and Healy, W. (2024), Research on Fixture-Level Peak Probability of Water Use in Commercial Buildings, Grant/Contract Reports (NISTGCR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.GCR.24-053, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958131 (Accessed October 9, 2025)