Water Conservation: Identifying Targets
December 23, 2013
With the growing need to reduce water use, maintenance and engineering managers might wonder which areas of facilities to focus on first. Before performing a plumbing retrofit with the latest and greatest water-efficiency technologies, managers need to understand the way a facility is performing in terms of water efficiency. The first step in this process is establishing a baseline for water use from current utility bills.
For example, compile the last five years of utility bills and document water use for each month in a format that enables a comparison from year to year. Set the first year as the baseline. If the facility has implemented water-efficiency measures in the past five years, compare current use against this baseline to determine how much the facility has improved.
The next step in the process is to determine all components and systems in the facility that use water. This step includes documenting restroom plumbing fixtures, as well as major systems that use water. These include systems considered process loads, such as cooling towers and commercial kitchens.
One strategy for understanding the amount of water each system consumes is using sub-meters. By installing sub-meters, managers can quantify consumption and specifically target conservation measures.
Typically, most water use in an office building relates to restroom plumbing fixtures. The building's construction can have a great deal to do with the types of fixtures installed. The Uniform Plumbing Code (UPC) and International Plumbing Code (IPC) typically dictate plumbing requirements for new construction. The table below compares plumbing fixture flow rates and requirements during different periods.