Equation 6-2. Water Savings From Retrofitting or Replacing Single-Pass Cooling
Equipment (gallons per year)
= Current Water Use of Single-Pass Cooling Equipment
Current Water Use of Single-Pass Cooling Equipment (gallons per year)
To calculate the simple payback from the water savings associated with replacing ex-
isting equipment cooled with single-pass water, consider the equipment and instal-
lation cost of the replacement option, the water savings as calculated using Equation
and the facility-specific cost of water and wastewater.
If single-pass cooling is eliminated by replacing equipment with air-cooled models,
facilities might see an increase in energy usage. The increased energy use, depending
upon how significant, might increase the payback time and decrease 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