October 2012
6-7
Equation 6-2. Water Savings From Retrofitting or Replacing Single-Pass Cooling
Equipment (gallons per year)
= Current Water Use of Single-Pass Cooling Equipment
Where:
••
Current Water Use of Single-Pass Cooling Equipment (gallons per year)
Payback
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
6-2,
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
cost-effectiveness.
Additional Resources
EPA and DOE, Energy Efficiency & Renewable Energy, Federal Energy Management
Program. May 2005.
Laboratories for the 21
st
Century: Best Practices, Water Efficiency
Guide for Laboratories
.
.
6.2
Single-Pass Cooling
