Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

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



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


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.
Grant/Contract Reports (NISTGCR) - 24-053
Report Number


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


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],, (Accessed June 17, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created June 5, 2024