Publication Date

Spring 2011

Degree Type


Degree Name

Master of Science (MS)


Mechanical and Aerospace Engineering


Nicole Okamoto


Data Center, Economizer, Exergy

Subject Areas

Mechanical Engineering; Energy


Electrical consumption for data centers is on the rise as more and more of them are being built. Data center owners and operators are looking for methods to reduce energy consumption and electrical costs. One method of reducing facility costs for a chilled water plant is by adding an economizer. Most studies concerning economizer systems are conducted largely by looking at energy alone since the primary focus is reducing electrical costs. Understanding how much exergy is destroyed, where it is destroyed, and why it is destroyed provides a more complete view on how environmental impacts can be minimized while reducing energy usage.

The purpose of this study is to develop energy and exergy-based models of the most common economizer systems. A normal chiller plant without an economizer and a chiller plant with an indirect wet-side economizer (the most common type of economizer system) are compared. Results show outdoor conditions influence facility energy consumption and exergy destruction. For a chiller plant operating with an economizer, the CRAH is found to be the largest source for exergy destruction. For a chiller plant without an economizer, the chiller is the largest source for exergy destruction.