Page 70 - WaterSense at Work

October 2012
up over time. It is also important to carefully adhere to manufacturer-recommended
cleaning and maintenance requirements to ensure products continue to perform as
Savings Potential
Water savings can be achieved by replacing existing flushing urinals with WaterSense
labeled flushing urinals, which use no more than 0.5 gpf. To estimate facility-specific
water savings and payback, use the following information.
Current Water Use
To estimate the current water use of an existing flushing urinal, identify the following
information and use Equation 3-3:
Flush volume of the existing urinal. Urinals installed prior to 1994 have flush
volumes that typically range between 1.5 and 3.5 gpf. Urinals installed in 1994 or
later have flush volumes of 1.0 gpf.
Average number of times the urinal is flushed per day, which will be dependent
on the number of male building occupants. Male building occupants use the
urinal two times per day on average.
Days of facility operation per year.
Equation 3-3. Water Use of Urinal (gallons per year)
= Urinal Flush Volume x Number of Flushes x Days of Facility Operation
Urinal Flush Volume (gallons per flush)
Number of Flushes (flushes per day)
Days of Facility Operation (days per year)
Water Use After Replacement
To estimate the water use of a replacement WaterSense labeled flushing urinal, use
Equation 3-3, substituting the flow rate of the replacement WaterSense labeled flush-
ing urinal. WaterSense labeled flushing urinals use no more than 0.5 gpf.
Water Savings
To calculate water savings that can be achieved from replacing an existing flushing
urinal, identify the following information and use Equation 3-4:
Vickers, Amy. 2001.
Handbook of Water Use and Conservation
WaterPlow Press.