Page 38 - WaterSense at Work

WaterSense at Work: Best Management Practices for Commercial and Institutional Facilities
An important rule in water management is that you can’t manage what you don’t
measure. Tracking a facility’s total water use, as well as specific end uses, is a key com-
ponent of the facility’s water-efficiency efforts. Source meters measure the amount
of water being supplied to the facility, while submeters measure usage for specific
activities, such as cooling tower, process, or landscape water use. Accurately measur-
ing water use can help facility managers identify areas for targeted reductions and to
track progress from water-efficiency upgrades. Submeters can also help identify leaks
and indicate when equipment is malfunctioning.
Meters and submeters can be integrated into a centralized building management sys-
tem, making it easy to track usage and implement a water management plan (see
tion 1.2: Water Management Planning
These systems are capable of electronically storing
data frommeters and submeters, reporting hourly, daily, monthly, and annual water use.
They can also trigger alerts when leaks or other operational anomalies are detected.
Installing the correct meter and ensuring it functions properly are critical to accurate
water measurement. There are many types and sizes of meters intended for different
uses, so it is important to choose the correct one. Improper sizing or type can cause
problems for the building. For example, an undersized water meter can cause exces-
sive pressure loss, reduced flow, and noise. Oversized meters are not economical and
do not accurately measure minimal flow rates.
All utility-grade water meters manu-
factured and installed for domestic water service by a water utility in the United
States must comply with American Water Works Association (AWWA) standards. Sub-
meters that are installed for water management purposes and not used for revenue
purposes are not subject to such standards.
Best Practices
There are several best practices for metering water use, including correctly choos-
ing what to meter and submeter; selecting, installing, and maintaining meters; and
reading and recording metered data to track water use and integrate it into the water
management plan.
DeterminingWhat to Meter and Submeter
It’s best to meter all water conveyed to the facility, regardless of source. For example,
even if a building’s water is solely supplied by an alternative source (e.g., municipally
supplied reclaimed water), a source meter can still be installed to track and manage
water use.
If multiple sources of water are provided to a facility, each source should
be metered and tracked separately.
Metering and Submetering
Smith, Timothy A. Park Environmental Equipment Company, LTD. April 22, 2008.
Water-Meter Selection and Sizing
U.S. Green Building Council’s LEED.® November 2010.
Building Design and Construction
Page 151.