October 2012
4-33
4.7
Dipper Wells
Equation 4-14. Water Use of Push-Button, Metered Faucet (gallons per year)
= Flow Rate of Push-Button, Metered Faucet x Uses per Hour x Daily Use
Time x Days of Facility Operation
Where:
••
Flow Rate of Push-Button, Metered Faucet (gallons per cycle)
••
Uses per Hour (cycles per hour)
••
Daily Use Time (hours per day)
••
Days of Facility Operation (days per year)
Water Savings
To calculate the water savings that can be achieved from replacing an existing dipper
well with a push-button, metered faucet, identify the following information and use
Equation 4-13:
••
Current water use as calculated using Equation 4-12.
••
Water use after replacement as calculated using Equation 4-14.
Payback
To calculate the simple payback from the water savings associated with replacing
an existing dipper well with a push-button, metered faucet, consider the equipment
and installation cost of installing the new push-button, metered faucet; the water
savings as calculated in Equation 4-13; and the facility-specific cost of water and
wastewater.
After replacing an existing dipper well with a push-button, metered faucet, facilities
may save energy from the reduced hot water use. This energy savings will further
reduce the payback period and increase replacement cost-effectiveness.
Dipper Well Replacement With an ENERGY STAR Qualified Dishwasher
Although installing a dipper well retrofit is likely the most cost-effective choice for a
facility, significant water savings can also be achieved by replacing a dipper well with
an ENERGY STAR qualified commercial undercounter dishwasher.
Current Water Use
To estimate the current water use of an existing dipper well, use Equation 4-12.
