Peak Water Demand Study: Full Study is a comprehensive analysis redefining water supply system sizing for residential and multifamily buildings. Based on real-world data from more than 1,000 households, the full study provides an evidence-based approach to right-sizing plumbing systems—demonstrating reductions in water waste, construction costs, and public health risks.
IAPMO and ASPE, along with funding from the Water Quality Research Foundation (WQRF), convened a special task force to revise the methodology for properly estimating premise water supply demands in response to the increased use of water-conserving plumbing fixtures, fixture fittings, and appliances and the subsequent decreased demand for water in commercial buildings and residences. The charge of the task group was to develop a statistically based probability model that would predict the peak water demand for single- and multifamily dwellings having water-conserving plumbing fixtures.
A revolutionary tool, IAPMO’s Water Demand Calculator® accurately predicts peak water demand in single-family homes and multifamily buildings. Right-sizing of the piping system helps decrease construction costs, reducing the carbon footprint of the structure and saving consumers on both their water and water heating-related energy utility bills for the entire life of the plumbing system. At the same time, right-sizing has the potential to reduce the threat of bacterial growth within the system, which can lead to such serious health risks as Legionnaires’ disease.
Key parts of the study include:
- Results and recommendations for the end use of fixture and appliance flow rates
- Description of the fixture use probabilities that were observed as part of a more than 1,000-home data set
- Explanation of the algorithms used in calculating peak flow rates as part of the Water Demand Calculator
“By leveraging real-world data, this study not only proves that right-sizing plumbing systems can reduce water waste and construction costs, but it also plays a crucial role in enhancing public health and minimizing environmental impact,” said Dan Cole, Senior Director of Technical Services and Research. “We’re excited to offer the Water Demand Calculator as a revolutionary tool that will empower builders, designers, and consumers to make smarter, more sustainable choices for the future.”
IAPMO encourages plumbing professionals, regulators, and builders to adopt these findings. The study supports the expanded use of the Water Demand Calculator, already implemented in multiple states and jurisdictions.
Access the full study at iapmo.org/research/whitepapers-and-studies/peak-water-demand-full-study.
