October 2012
7-23
7.4
Steam Sterilizers
that can be achieved from replacing an existing steam sterilizer with one that has an
electric liquid-ring vacuum pump, identify the current water use of the equipment, as
calculated using Equation 7-6, and use Equation 7-8.
Equation 7-8. Water Savings From Steam Sterilizer Retrofit With Liquid-Ring
Vacuum Pump (gallons per year)
= Current Steam Sterilizer VacuumWater Use x Savings (0.75)
Where:
••
Current Steam Sterilizer VacuumWater Use (gallons per year)
••
Savings (percent)
Payback
To calculate the simple payback from the water savings associated with replacing a
steam sterilizer with one with a liquid-ring vacuum pump, consider the equipment
and installation cost of the replacement, the water savings as calculated using Equa-
tion 7-8, and the facility-specific cost of water and wastewater.
By replacing a steam sterilizer with one with a liquid-ring vacuum pump, facilities
should also consider the potential increase or decrease in energy use. The energy use
will also affect the payback period and replacement cost-effectiveness.
Additional Resources
Alliance for Water Efficiency. Steam Sterilizer & Autoclaves Introduction.
EPA and DOE, Energy Efficiency & Renewable Energy, Federal Energy Management
Program (FEMP). May 2005.
Laboratories for the 21
st
Century: Best Practices, Water
Efficiency Guide for Laboratories
.
Pages 5-6.
.
DOE, Energy Efficiency & Renewable Energy, FEMP.
Water Efficiency Improvements at
Various Environmental Protection Agency Sites
.
.
Koeller, John, et al. August 2004.
A Report on Potential Best Management Practices
.
Prepared for the California Urban Water Conservation Council. Pages 23-34.
van Gelder, Roger E. and Leaden, John. University of Washington. 2003.
Field Evalua-
tion of Three Models of Water Conservation Kits for Sterilizer Trap Cooling at University of
Washington
.
.
