calculate the maximum potential water savings using the water use corresponding
to the fewest average number of rinse cycles needed at the facility.
To calculate the water savings that can be achieved from the replacement of an exist-
ing glassware washer, identify the following information and use Equation 7-10:
Current water use as calculated using Equation 7-9.
Water use after replacement as calculated using Equation 7-9.
Equation 7-10. Water Savings From GlasswareWasher Replacement (gallons per
= Current GlasswareWasher Water Use –Water Use After Glassware
Current Glassware Washer Water Use (gallons per year)
Water Use After Glassware Washer Replacement (gallons per year)
To calculate the simple payback from the water savings associated with replacing
an existing glassware washer, consider the equipment and installation cost of the
replacement glassware washer, the water savings as calculated using Equation 7-10,
and the facility-specific cost of water and wastewater.
By reducing water use in a glassware washer, facilities can also save a significant
amount of energy, since most of the water used during the rinse cycles is hot water.
This energy savings will further reduce the payback period and increase replacement
EPA and DOE, Energy Efficiency & Renewable Energy, Federal Energy Management
Program. May 2005.
Laboratories for the 21
Century: Best Practices, Water Efficiency
Guide for Laboratories